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EE111010220267487223, Swedbank EE162200221068426764
Terviseamet
kuupäev digitaalallkirjas nr 7-1/165
Selgituse küsimine
Põhja-Pärnumaa Vallavalitsuse menetluses on tuuleparkide eriplaneeringu asukoha
eelvaliku otsuste eelnõude ja keskkonnamõju strateegilise hindamise esimese etapi aruande
koostamine. Eriplaneeringu koostamise eesmärgiks on elektrienergia tootmiseks rajatavatele
tuuleparkidele ja selle toimimiseks vajalikule taristule sobivate arendusalade leidmine.
Eriplaneeringu avalikul väljapanekul esitati asukoha eelvaliku otsuste eelnõude ja
keskkonnamõju strateegilise hindamise esimese etapi aruande kohta arvamusi. Palume Teie
selgitust MTÜ Looduse ja Inimeste Eest poolt esitatud „Rahvusvahelise Akustiliste
Uuringute Organisatsiooni [International Acoustics Research Organization (IARO)]
teaduslik eksperthinnang“-le vastamisel.
• Palume selgitada, kas Eestis kehtivad normid kaitsevad ainult kuulmiskahjustuse
eest aga ei kaitse muude tervisehädade eest?
• Tuugenite tekitatava müra modelleerimisel peetakse kokkupuute tagajärjena silmas
vaid kuulmislangust, sest kõik arvandmed on esitatud A-kaalutud detsibellides
(dBA), mis tähendab, et vaadeldakse ainult kuuldavat müra. Miks kasutatakse
peamiselt A-korrektsiooni, kas seda võib pidada asjakohaseks lähenemiseks?
• Kas on teada, et Eestis kasutatav tuulikute müra hindamise metoodika on
tunnistatud ebakompetentseks?
• Kas esitatud arvamus on teaduslik ja omab sisulist mõju Eesti tuulikute müra mõju
hindamise praktikale?
• Kas KSH-s kasutatud müra mõju hindamise osas on vaja kasutatud metoodika osas
teha muudatusi?
Ootame Teie selgitusi, et arvamuse avaldajale vastata ja eriplaneeringu menetlusega jätkata.
Lugupidamisega
(allkirjastatud digitaalselt)
Madis Koit
vallavanem
Lisa: 7-1-1003-321.
2 (2)
Lisa: 321 lisa 15JAN25—ANNEX B—Excerpt from 2024 IARO Arnicle Health Report
Lisa: 321 lisa 15JAN25—MAP—Estonian Response Report
Lisa: 321 lisa 15JAN25—ANNEX A —English Translation of Kobras SEA Report –
Section 4-6-1—Noise
Lisa: 321 lisa IARO 2025-Jan- 15 aruanne PP valla EP KSH (2024- nov) kohta- kokkuvõte
Erich Palm
Annex B Excerpt from Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland, UK (IARO Document IARO24-C1, pp 59-71)
(Annexed to IARO Report No. IARO25-1)
The full Health Report is available at: IARO.org.nz
January 2025
Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland
Document IARO24-C1
June 2024
Page 2 of 162 International Acoustics Research Organization 37 Weston Ave, Palmerston North, New Zealand T +64 21 033 6528 http://IARO.org.nz
International Acoustics Research Organization
IARO is an international group of researchers with a mission to investigate acoustical environments, especially with respect to features that affect humans and animals, and to publish the results. IARO holds the ethics approval for the CSI-ACHE, the Citizen Science Initiative into Acoustical Characterisation of Human Environments, the results of which are publicly disseminated.
Contacts:
IARO, 37 Weston Ave, Palmerston North, 4414, New Zealand
Tel: +64 21 033 6528
Email: [email protected]
This Health Report accompanies the December 2023 IARO Report No. IARO23-C1—High- Resolution Infrasonic and Low-Frequency Sound Recordings conducted at Arnicle Farm, Glenbarr, Argyll, Scotland in 2022 and 2023.
IARO does not use generative language artificial intelligence tools to construct their reports.
Authors of this Report (alphabetical)
Mariana Alves-Pereira, Ph.D., Lusófona University, Lisbon, Portugal
Huub Bakker, Ph.D., IARO, Palmerston North, New Zealand
Susan Crosthwaite, Citizens’ Initiative UK, Scotland
Rachel Summers, IARO, Palmerston North, New Zealand
Page 3 of 162 International Acoustics Research Organization 37 Weston Ave, Palmerston North, New Zealand T +64 21 033 6528 http://IARO.org.nz
CONTENTS
SYNOPSIS ................................................................................................................................................ 8
EXECUTIVE SUMMARY .................................................................................................................................. 9
A. INTRODUCTION .................................................................................................................................. 11 I. Goals of this IARO Health Report ............................................................................................................... 11 II. Disclaimer ................................................................................................................................................... 11 III. International Acoustics Research Organization, IARO ................................................................................ 12 IV. Ethics Approval ........................................................................................................................................... 12 V. Acronyms and Variables Used in this Report and Appendices ................................................................... 12
B. BACKGROUND ON ARNICLE FARM ...................................................................................................... 14 I. Arnicle Farm, Glenbarr, Tarbert, Scotland ................................................................................................. 14 II. Noise measurements at Arnicle Farm ........................................................................................................ 15 III. Medical issues among Arnicle Farm residents ........................................................................................... 16
C. RATIONALE FOR THE ORGANISATION OF THIS REPORT ....................................................................... 17 I. Prior assertions by NHS Consultants on the matter at hand ...................................................................... 17 II. NHS-Highland Letter dated 20 November 2023 ......................................................................................... 18 III. The mandatory requirement for an educational approach ....................................................................... 19
D. THE 20-NOV-2023 NHS LETTER TO ARNICLE FARM AS AN EDUCATIONAL TOOL ................................... 21 1. “Alleged Noise” .................................................................................................................................... 21
I. The “alleged noise” .................................................................................................................................... 21 II. Medical professionals and industry-employed acousticians ...................................................................... 25 III. ‘Dose’ in the Medical Sciences’ dose-response relationship ...................................................................... 26 IV. ‘Dose’ of infrasound and low frequency noise ........................................................................................... 27
2. The Measured ‘Dose’ at Arnicle Farm .................................................................................................... 30 I. Physical attributes of the Dose of the physical agent ................................................................................ 30 II. Quantifying WTAS to establish a measure of Dose .................................................................................... 33 III. Quantifying exposure time to the measured WTAS Dose .......................................................................... 34 IV. Cumulative exposures from multiple WPPs ............................................................................................... 36
3. "From a Health Perspective” ................................................................................................................. 38 I. “Excessive noise is increasingly recognised as a significant public health issue” ....................................... 38 II. Exposure time at Arnicle Farm ................................................................................................................... 41 III. “Relieving factors” ...................................................................................................................................... 42
4. “As described by the World Health Organization” ................................................................................. 44 5. The Expert Panel of the Council of Canadian Academies ....................................................................... 45
I. The Charter given to the Expert Panel ....................................................................................................... 45 II. ‘Dose’ according to the Expert Panel of the Council of Canadian Academies ............................................ 46 III. The ‘Response’ of the dose-response relationship according to the Expert Panel .................................... 53 IV. Summary of the results achieved by the Expert Panel of Council of Canadian Academies ....................... 56
6. Other studies cited in the Letter ............................................................................................................ 59 I. Immediate effects of infrasound exposure ................................................................................................ 60 II. The Government-Sponsored Finnish Study ................................................................................................ 64 III. Intuitive symptoms ..................................................................................................................................... 67
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7. 2018 WHO Guidelines for Environmental Noise ..................................................................................... 68 8. The Diagnosis, or Rather, the Misdiagnosis ............................................................................................ 71
I. “This is a commonly recognized phenomenon” ......................................................................................... 71 II. “Although there may not be any direct physical health effects” ............................................................... 72 III. The physical agent of disease that is dismissed, and then tries to emerge as a psychosocial factor ......... 73
9. Therapeutic course of action: “Mindfulness, Meditation and Cognitive Behavioural Therapy” ............... 73
E. FURTHER EDUCATIONAL EFFORTS TO AUGMENT NHS-HIGHLAND’S UNDERSTANDING OF THE CLINICAL SITUATION AT ARNICLE FARM ............................................................................................................ 76 I. The Onset of Symptoms ............................................................................................................................. 76 II. Prior noise-exposures and current exposure times ................................................................................... 79 III. Increased susceptibility to this agent of disease ........................................................................................ 81 IV. Animal Data ................................................................................................................................................ 83
F. DISCUSSION ....................................................................................................................................... 86 I. Changing a paradigm or recognizing the obvious? .................................................................................... 86 II. Arnicle Farm and Blary Hill ......................................................................................................................... 87 III. What to do? ................................................................................................................................................ 89
G. CONCLUSIONS .................................................................................................................................... 91
H. RECOMMENDATIONS ......................................................................................................................... 93
I. APPENDIX 1—MEDICAL SCIENCES ....................................................................................................... 94 I. What is a Physical Agent of Disease? ......................................................................................................... 94 II. What parameters are important when investigating the biological effects of exposures to physical
agents of disease? ...................................................................................................................................... 94 a. Exposure Times: ............................................................................................................................... 94 b. Cumulative Effects: .......................................................................................................................... 95 c. Recovery Times: ............................................................................................................................... 95
III. How are physical agents of disease quantified? ........................................................................................ 95 IV. How is noise quantified? ............................................................................................................................ 95 V. What is the difference between ‘noise’ and ‘vibration’? ........................................................................... 96 VI. What are Dose-Response relationships? .................................................................................................... 97 VII. How is Dose measured? ............................................................................................................................. 98 VIII. How is Response measured? ...................................................................................................................... 98 IX. Is annoyance a proper measure of Response for wind turbine noise exposure? ...................................... 99 X. How are control populations selected for noise studies? ........................................................................ 100 XI. What happens when control populations are incorrectly selected? ....................................................... 101
J. APPENDIX 2—PHYSICS OF ACOUSTICS .............................................................................................. 104 I. What is Sound? ......................................................................................................................................... 104 II. What is Infrasound and Low Frequency Noise? ....................................................................................... 106 III. Why is noise generally measured in dBA? ................................................................................................ 106 IV. Can infrasound and low frequency noise be measured in dBA? .............................................................. 108 V. Can infrasound and low frequency be measured in dBC or dBG? ............................................................ 110 VI. How are infrasound and low frequency noise properly quantified? ........................................................ 112 VII. Why is a psychosomatic (nocebo) origin attributed to the effects of infrasound and low frequency noise?
.................................................................................................................................................................. 113 VIII. What happens when people complain of infrasound and low frequency noise to industry-employed
acousticians? ............................................................................................................................................ 117
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K. APPENDIX 3—WIND TURBINE ACOUSTIC SIGNATURES ..................................................................... 119 I. What is a wind turbine acoustic signature? ............................................................................................. 119 II. How are wind turbine acoustic signatures measured? ............................................................................ 120 III. What are Harmonic Prominences? .......................................................................................................... 122 IV. How is Dose measured when the agent of disease is WTAS? .................................................................. 123 V. If each wind turbine model generates its own WTAS, what happens when there are more than one WPP
with different wind turbine models? ....................................................................................................... 124
L. APPENDIX 4—CLINICAL & BIOLOGICAL MATTERS ............................................................................. 127 1. Cellular and Tissue Biology .................................................................................................................. 127
I. What is the structure of a mammalian cell? ............................................................................................ 127 II. What is a cellular mechanoreceptor? ...................................................................................................... 130 III. Biological tissues are viscoelastic—What does this mean? ..................................................................... 131 IV. What are dermal mechano-receptors? .................................................................................................... 134 V. What is the Fascia? ................................................................................................................................... 135 VI. Is oxidative stress an important factor in infrasonic exposures? ............................................................. 137
2. The Brain and the Ear ........................................................................................................................... 139 I. What is the brainstem? ............................................................................................................................ 139 II. What is the respiratory drive or the hyperventilatory reflex? ................................................................. 140 III. How is the respiratory drive evaluated? .................................................................................................. 140 IV. Is the measure of the respiratory drive an appropriate Response for the dose-response relationship
when the Dose is an acoustic agent of disease? ...................................................................................... 140 V. Is there other evidence of brainstem lesions among infrasound and low frequency noise-exposed
persons? ................................................................................................................................................... 142 VI. Have other effects of infrasound on the brain been studied? ................................................................. 142 VII. Is there evidence of respiratory pathology among infrasound and low frequency noise-exposed persons?
.................................................................................................................................................................. 143 VIII. How does the ear process infrasonic information? ................................................................................. 145 IX. Why is the ear considered an ‘organ of alarm’? ...................................................................................... 146 X. Why is sleeping in this type of contaminated environment so detrimental to health? ........................... 148
3. Occupational and Residential Exposures .............................................................................................. 148 I. Why are occupational exposures important to understand environmental exposures? ......................... 148 II. What extra-auditory medical conditions do noise-exposed workers develop? ....................................... 149 III. Do the extra-auditory medical conditions seen in noise-exposed workers also emerge in residential
infrasonic exposures? ............................................................................................................................... 152 IV. What is pericardial thickening in noise-exposed persons? ...................................................................... 153 V. Can noise act as a genotoxic agent? ......................................................................................................... 157 VI. Are balance disturbances an example of extra-auditory medical conditions developed among noise-
exposed persons? ..................................................................................................................................... 159 VII. Are auto-immune disorders an example of extra-auditory medical conditions developed among noise-
exposed persons? ..................................................................................................................................... 161
ANNEX A: Technical Background for Laypersons ANNEX B1 through B6: Documentation.
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min averages), and the concomitant ill-chosen health endpoints (such as annoyance, salivary cortisol levels, hearing loss) as measures of health effects.
9 Research on long-term exposure to wind turbine noise would provide a better understanding of the causal associations between wind turbine noise exposure and certain adverse health effects. In theory, this would be true, but not if the same unscientific assumptions are maintained, if the same incomplete assessment of dose is continued, and if the same non-primary and subjective adverse health effects are chosen for investigation.
10 Technological development is unlikely to resolve, in the short term, the current issues related to perceived adverse health effects of wind turbine noise. “Perceived”? 296 (see Paragraphs 45, 57 and 58).
11 Impact assessments and community engagement provide communities with greater knowledge and control over wind energy projects and therefore help limit annoyance. Annoyance is here clearly implied to be a result of psychosocial factors, and it appears to be the only health endpoint that merits attention.
212. The work produced by the 2015 Expert Panel on Wind Turbine Noise and Health of the Council of Canadian Academies, and the conclusions at which it arrives, are only marginally relevant to the matter at hand.
6. Other studies cited in the Letter
The dearth of knowledge on the matter at hand continues to be demonstrated by the signatory of the Letter:
“In addition to the impacts of audible noise itself, the contribution from low frequency infrasound to health effects has also been postulated although findings from recent studies have suggested that this is not supported. 297,298 Similarly, Turunen et al. whilst unable to assess a causal relationship due to the
296 See Appendix 2—Physics of Acoustics: VII. Why is a psychosomatic (nocebo) origin attributed to the effects of infrasound and low frequency
noise?
297 Footnote 5 of the Letter. Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/ [website added]
298 Footnote 6 of the Letter. Maijala PP, Kurki I, Vainio L, Pakarinen S, Kuuramo C, et al. (2021) Annoyance, perception, and physiological effects of wind turbine infrasound. Journal of the Acoustical Society of America, 149(4): 2238-2248. https://pubmed.ncbi.nlm.nih.gov/33940893/ [website added]
Page 60 of 162 International Acoustics Research Organization 37 Weston Ave, Palmerston North, New Zealand T +64 21 033 6528 http://IARO.org.nz
cross-sectional nature of the study, suggested that interpretations of symptoms are affected by other factors in addition to the actual exposure.299”
213. For educational purposes,300 a brief review is conducted of the three studies cited above by the NHS-Highland medical representative.
I. Immediate effects of infrasound exposure
214. In the 2023 study by Marshall et al.,301, 302 the objective is stated as follows:
We aimed to test the effects of 72 h of infrasound (1.6–20 Hz at a sound level of ∼ 90 dB pk re 20 microPa, [303 , 304 ] simulating a wind turbine infrasound signature) exposure on human physiology, particularly sleep.
215. In Medical Sciences, this type of study purports to investigate the immediate effects of exposure, as opposed to long-term effects:
Our principal hypothesis was that exposure to infrasound in healthy individuals, at a level of ∼ 90 dB pk re 20 microPa compared with the sham infrasound, increases WASO [305] —a measure of sleep disturbance—and worsens other measures of sleep quality, mood, WTS [306] symptoms, and other electrophysio- logical measures. In addition, as a positive control, we also tested whether audible traffic noise, a mixture of road (motorbike, truck, car) and aircraft noise
299 Footnote 7 of the Letter. Turunen AW, Tittanen P, Yli-Tuomi T, Taimisto P, Lanki T. (2021) Symptoms intuitively associated with wind turbine infrasound.
Environmental Research, 192: 1-9. https://pubmed.ncbi.nlm.nih.gov/33131679/ [website added]
300 As indicated in Paragraphs 37 and 40, the primary reason for such a comprehensive approach to this IARO Health Report is to
provide an educational and instructive document for the NHS-Highland medical staff, with the ultimate purpose of benefiting
the Scottish Citizen.
301 Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/
302 Disclaimer included in the 2023 Marshall et al. paper: “All of the authors have superannuation accounts which are compulsory
in Australia and these accounts may contain investments in both traditional and renewable energy, including wind turbines.
R.T. is the founding principal of Renzo Tonin Associates who have previously worked as consultants for the NSW Department
of Planning on several wind farms in NSW, Australia. None of the investigators have any other pecuniary interest or academic
conflicts of interest in the outcomes of this study.“
303 See Appendix 1—Medical Sciences: IV. How is noise quantified?
304 See Appendix 2—Physics of Acoustics: I. What is Sound?
305 WASO = Wakefulness After Sleep Onset is the total number of minutes that an individual is awake after having initially fallen
asleep.
306 WTS = Wind Turbine Syndrome. See: Pierpont N. (2009) Wind Turbine Syndrome: A Report on a Natural Experiment. K-Selected Books: Santa Fe, New Mexico, USA. https://www.researchgate.net/publication/265247204_Wind_Turbine_Syndrome_A_Report_on_a_Natural_Experiment
Page 61 of 162 International Acoustics Research Organization 37 Weston Ave, Palmerston North, New Zealand T +64 21 033 6528 http://IARO.org.nz
(at a sound level of 40–50 dB LAeq; night and 70 dB LAFmax transient maxima)
had an adverse impact on these same outcomes, when compared with sham infrasound.307
216. The conclusions of this study were:
Our study found no evidence that 72 h of exposure to a sound level of ∼ 90 dB pk re 20 microPa of simulated wind turbine infrasound in double-blind conditions perturbed any physiological or psychological variable. None of the 36 people exposed to infrasound developed what could be described as WTS. Our study is unique because it measured the effects of infrasound alone on sleep. This study suggests that the infrasound component of WTN [wind turbine noise] is unlikely to be a cause of ill-health or sleep disruption, although this observation should be independently replicated.
217. The dose presented to these subjects “simulating a wind turbine infrasound signature” was questioned by IARO scientists, and correspondence with co-author R. Tonin was exchanged (in May 2023) to ascertain what “simulated wind turbine infrasound” meant.
218. Regrettably, the material provided by co-author R. Tonin was regarded by IARO scientists as unsatisfactory, if “simulating a wind turbine infrasound signature” was the objective.308
219. Nevertheless, for the sake of scientific discussion, it will be temporarily accepted that the subjects of this study were actually presented with a properly simulated wind turbine infrasound signature.
307 Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind
Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/ [Footnotes contained in the original text are not included.]
308 The acoustic pattern used to simulate the wind turbine signal had a sawtooth profile, not the short-duration pulses of WTAS,
see Figure 3. A sawtooth-shaped wave has a quick onset, a slow decay, and only locally oscillates the air. WTAS has a rapid
onset and decay, and ‘pumps the air’ (as proposed by Dr Stephan Kaula, Germany), rather than only causing the local
oscillations that are typically seen in airborne, acoustic propagation phenomena.
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220. The idea seems to have been to investigate immediate responses to the simulated wind turbine infrasound signature, but as measured by parameters that, perhaps, were not so relevant for assessing immediate responses.309, 310, 311, 312, 313, 314, 315
221. Another questionable practice was the selection of the “healthy individuals” as study subjects. To the understanding of IARO scientists, no evaluation was made regarding prior exposures 316 to infrasound and low frequency noise.317, 318
222. Marshall et al. explain the viewpoint that foundationally justifies their study:
People who suffer from WTS [Wind Turbine Syndrome 319] report that their symptoms begin quickly when they are exposed to infrasound from wind turbines and are then sustained.[320] Our scientifically robust study provides evidence to address this claim. The Australian NHMRC [National Health and Medical Research Council] report that gave rise to our study made note of this “absence of evidence” rather than concluding an “evidence of absence” owing to the lack of any laboratory-controlled double-blind experiments of sufficient duration and intensity to hypothetically induce WTS in a human.321
309 See Appendix 4—Clinical & Biological Matters, Section 3-Occupational and Residential Exposures: I. Why are occupational exposures important
to understand environmental exposures?
310 See Appendix 4—Clinical & Biological Matters, Section 3-Occupational and Residential Exposures: II. What extra-auditory medical conditions do noise-exposed workers develop?
311 See Appendix 4—Clinical & Biological Matters, Section 3-Occupational and Residential Exposures: III. Do the extra-auditory medical conditions seen in noise-exposed workers also emerge in residential infrasonic exposures?
312 Mohr GC, Cole JJN, Guild E, von Gierke HE. (1965) Effects of low-frequency and infrasonic noise on man. Aerospace Medicine, 36: 817-24.
313 Ponomarkov VI, Tysik A, Kudryavtseva VI, Barer AS. (1969) Biological action of intense wide-band noise on animals. Problems of Space Biology NASA TT F-529, 7(May): 307-9.
314 Castelo Branco NAA, Gomes-Ferreira P, Monteiro E, Costa e Silva A, Reis Ferreira J, Alves-Pereira M. (2003) Respiratory epithelia in Wistar rats after 48 hours of continuous exposure to low frequency noise. Journal of Pneumology, formerly Revista Portuguesa Pneumologia, IX (6): 474-79. https://pubmed.ncbi.nlm.nih.gov/15190432/
315 Castelo Branco NAA, Reis Ferreira J, Alves-Pereira M. (2007). Respiratory pathology in vibroacoustic disease: 25 years of research. Journal of
Pneumology, formerly Revista Portuguesa Pneumologia, XIII (1): 129-135. https://pubmed.ncbi.nlm.nih.gov/17315094/
316 Including, foetal, childhood and young adult exposures in residential, occupational, and leisurely settings. See Appendix 1— Medical Sciences: II. What parameters are important when investigating the biological effects of exposures to physical agents of disease.
317 See Appendix 1—Medical Sciences: X. How are control populations selected for noise studies.
318 See Appendix 1—Medical Sciences: XI. What happens when control populations are incorrectly selected?
319 Pierpont N. (2009) Wind Turbine Syndrome: A Report on a Natural Experiment. K-Selected Books: Santa Fe, New Mexico, USA. https://www.researchgate.net/publication/265247204_Wind_Turbine_Syndrome_A_Report_on_a_Natural_Experiment
320 See Appendix 4—Clinical & Biological Matters, Section 1-Cellular and Tissue Biology. III. Biological tissues are viscoelastic—What does this mean?
321 Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/ [Footnotes contained in the original text are not included.]
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223. “Induce WTS in a human”? 322 As far as is understood by IARO scientists, WTS is not commonly viewed as an immediate effect of the exposure to this agent of disease.323
224. The expression “laboratory-controlled double-blind experiments of sufficient duration and intensity” as applied to the matter at hand is simultaneously unethical, dangerous, and unnecessary.324, 325
225. Is it the desire of the Australian NHMRC to expose subjects to a toxic agent—which is very difficult, if not impossible, to reproduce in laboratory settings—until some clearly severe health endpoint is observed? While tens of thousands of citizens are sitting in real- life laboratories being ‘accused’ of developing psychosomatic disorders? 326
226. This methodology is considered by IARO scientists to reflect sub-standard practices of Scientific Inquiry.
227. In conclusion, in the opinion of IARO scientists, the effort expended by these authors to conduct this study is laudable (particularly given the position of the Australian NHMRC), even though, scientifically, within the realm of Medical Sciences and dose-response relationships, its results are inconsequential.
322 “The causes of this syndrome have been the subject of substantial international controversy. Proponents have contended that the symptoms
that compose this syndrome are caused by low frequency subaudible infrasound generated by wind turbines. Critics have argued that these symptoms are psychological in origin and are attributable to nocebo effects. The Australian National Health and Medical Research Council Wind Farms and Human Health Reference Group concluded that the available evidence was not sufficient to establish which, if either, of these explanations is correct.” See: Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/
323 Pierpont N. (2009) Wind Turbine Syndrome: A Report on a Natural Experiment. K-Selected Books: Santa Fe, New Mexico, USA. https://www.researchgate.net/publication/265247204_Wind_Turbine_Syndrome_A_Report_on_a_Natural_Experiment
324 What kind of “laboratory-controlled double-blind experiments of sufficient duration and intensity” were conducted for asbestos
contamination leading to asbestosis? Or for issues related to second-hand smoking, use of glyphosates, etc?
325 Alves-Pereira M, Rapley B, Bakker H, Summers R. (2019) Acoustics and Biological Structures. In: Abiddine Fellah ZE, Ogam E. (Eds) Acoustics of
Materials. IntechOpen: London. DOI: 10.5772/intechopen.82761.
326 In the opinion of IARO scientists, had this study been performed on 3 groups of people, differentiated by the extent of their
prior exposures (mild, moderate, or extensive), and, abiding by appropriate selection criteria of the study population, then,
perhaps, statistically useful numbers could have been obtained, and scientifically useful results could have been achieved. The
inability to reproduce ‘wind turbine infrasound’ under laboratorial conditions, however, would still render this study as
irremediably flawed, while its overall design could be deemed ethically questionable.
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II. The Government-Sponsored Finnish Study
228. The 2021 study by Maijala et al.327 is based on the 169-page 2020 Governmental Report on a Research Project carried out by Maijala et al.328
229. The main objective was “to find out whether wind turbine infrasound has harmful effects on human health.”329
230. Table 3 lists the specific objectives of this 2020 Research Project.
Table 3. Specific objectives of the 2020 Research Project sponsored by the Government of Finland.330
A. To characterize wind turbine noise as an exposure
1 What are the full spectrum sound levels, down to 0.1 Hz, inside houses near the wind power plants?
2 What are the characteristics of the sound, both audible and inaudible infrasound?
B. To describe symptoms that are intuitively associated with infrasound from wind turbines, i.e., wind turbine infrasound related symptoms.
3 What is the prevalence of wind turbine infrasound related symptoms in the vicinity of wind power plants?
4 What factors are associated with wind turbine infrasound related symptoms?
C. To study how infrasound produced by wind turbines affects humans, in particular, perception, annoyance, and physiological responses
5 Can low-frequency and infrasound wind turbine noise be perceived at typical and at extreme noise levels?
327 Maijala PP, Kurki I, Vainio L, Pakarinen S, Kuuramo C, et al. (2021) Annoyance, perception, and physiological effects of wind turbine infrasound. Journal
of the Acoustical Society of America, 149(4): 2238-2248. https://pubmed.ncbi.nlm.nih.gov/33940893/
328 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. https://julkaisut.valtioneuvosto.fi/handle/10024/162329
329 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 6. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
330 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 6-7. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
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6 What is the dependence between the depth of amplitude modulation and annoyance at low frequencies?
7 Does infrasound increase reported annoyance and psychophysiological responses?
8 What is the reactivity of the autonomic nervous system (ANS) to audible wind turbine sounds and its infrasound?
9 Are individuals who attribute their symptoms to wind turbines more sensitive to infrasound? Are they more able to detect infrasound and do they experience more annoyance compared to controls?
231. Objectives A1 and A2 were accomplished, and Figure 7 shows a representative example of the identified ‘dose.’
Figure 7. Representative example of the noise characterization (Raahe, indoors, 600-second sample). 331 LZ levels refer to unweighted dB values. LG refers to G-weighted values.332 LA refers to A-weighted values. Maximum and minimum LZ values are shown as curves.
331 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 21. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
332 See Appendix 2—Physics of Acoustics: V. Can infrasound be measured in dBC or dBG?
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232. Figure 7 shows a one-third-octave-band segmentation of the acoustic spectrum (similar to that shown in Figure 2). The solid black curve (LZ max) shows the highest sound pressure levels measured in unweighted dB.
233. There is no cut-off of spectral data as was seen in Figure 6 (i.e., the lower limiting frequency is 0.1 Hz and not 10 Hz), but there is also no recognition of a “wind turbine infrasound signal” as in the previous Marshall et al. study (see Paragraph 214). It was however recognized that “the most important frequencies were less than 2 Hz.”333
234. Objectives B3 and B4 (see Table 3) were more difficult to achieve, as “infrasound related symptoms” were established by questionnaires and telephone calls. While these types of surveys may have a certain usefulness, their direct results cannot be considered as a measure of Response within the realm of the Medical Sciences’ dose-response relationship,334 nor as per the WHO definition of noise-induced adverse health effects (see Paragraph 189).
235. Furthermore, there seems to not have been any stratification of the study population regarding prior noise exposure histories.335
236. Objectives C5 through C9 used “provocation experiments” conducted in an “infrasound chamber” whereby “systematically selected samples from real wind turbine sounds from wind power plant areas where inhabitants report symptoms associated with wind turbine infrasound or sound were used as stimuli.”336
237. As with the study by Marshall et al. (Paragraphs 224 to 226), it is not entirely understood why there is a perceived need to subject individuals in laboratory to a potentially noxious agent (which is very difficult, if not impossible, to reproduce under laboratorial conditions), while tens of thousands of individuals are living in ‘real-life laboratories,’ awaiting an objective, clinical observational study on behalf of the competent authorities.337
333 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 77. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
334 See Appendix 1—Medical Sciences: VIII. How is ‘Response’ measured?
335 See Appendix 1—Medical Sciences: II. What parameters are important when investigating the biological effects of exposures to physical agents of disease?
336 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 36 and 40. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
337 Although it is unclear to IARO scientists who (or what agency) could be classified as ‘the competent authorities.’
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III. Intuitive symptoms
238. In the third study of this series, the goal of Turunen et al.338 was to assess “the prevalence and severity of these wind turbine infrasound related symptoms:”
No matter what the true cause for the symptoms is, it is clear that symptoms are real and lead to worry, decreased quality of life, and potentially further to deteriorated health. High prevalence of this kind of phenomenon could be a serious threat to public health. The aim of this questionnaire study was to describe symptoms intuitively associated with infrasound from wind turbines.339
239. The immense wealth of data collected by this team of scientists was used to establish the prevalence of these self-reported “intuitive symptoms” from individuals living at different distances from WPPs: ≤ 2.5 km, 2.5–5 km, 5–10 km, and 10–20 km.
240. Figure 8 provides interesting information on the variation of self-reported “intuitive symptoms” with respect to distance from the WPP.
338 Please note that the authors of this study are the same as those of the Finnish Governmental study by Maijala et al. (see
Paragraph 228), and the data collected through questionnaires and telephone calls in the Maijala et al. study are the same data
used in this study. See: Turunen AW, Tittanen P, Yli-Tuomi T, Taimisto P, Lanki T. (2021) Symptoms intuitively associated with wind turbine infrasound. Environmental Research, 192: 1-9. https://pubmed.ncbi.nlm.nih.gov/33131679/
339 Turunen AW, Tittanen P, Yli-Tuomi T, Taimisto P, Lanki T. (2021) Symptoms intuitively associated with wind turbine infrasound. Environmental Research, 192: 1-9. https://pubmed.ncbi.nlm.nih.gov/33131679/
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Figure 8. “Smoothed association between distance to the closest wind turbine and the probability (logit scale) of wind turbine infrasound related symptoms (n = 1301)” (Footnote 339).
241. “Intuitive symptoms”, however, cannot be considered a bona fide Response applicable to the Medical Sciences’ dose-response relationships 340, 341 (see Paragraph 189).
7. 2018 WHO Guidelines for Environmental Noise
242. Environmental Noise Guidelines for the European Region is a 2018 document published by the WHO and that was quoted in the Letter sent by the NHS-Highland medical representative:
“In 2018, the WHO published guidelines342 to provide recommendations for protecting human health from exposure to environmental noise originating from a variety of sources including that of wind turbines. The importance of complete health which encompasses mental and social well-being and not solely the absence of disease was acknowledged in the development of the guidelines. As such, impacts on well-being, self-reported sleep disturbance and long-term annoyance were also considered. The guidelines included conditional recommendations in relation to wind turbine noise due to the quality of evidence. For average noise exposure, the conditional recommendation was to reduce noise levels produced by wind turbines below 45 dB Lden [343] [see Paragraph 66] as wind turbine noise above this level is associated with adverse health effects, specifically that of annoyance [344]. It was noted that there could be an increased risk factor for annoyance below this noise exposure level but that the lack of evidence meant that it could not state whether there was an increased risk for other health outcomes below this level. Similarly, as a result of the low quantity and heterogeneous nature of the
340 See Appendix 1—Medical Sciences: VI. What are Dose-Response relationships?
341 See Appendix 1—Medical Sciences: VIII. How is ‘Response’ measured?
342 Footnote 8 of the Letter. World Health Organization, Regional Office for Europe. Environmental Noise Guidelines for the European Region. Geneva: World health Organization; 2022. [The publication date of the document with this title is 2018.] https://www.who.int/europe/publications/i/item/9789289053563 [website added]
343 For a brief description of Lden see Table 1—Acronyms and variables used in this IARO Health Report.
344 Annoyance cannot be considered an “adverse health effect” (Response) within the context of the Medical Sciences’ dose-
response relationship (see Paragraphs 194 to 198), nor under the WHO definition for noise-induced adverse health effect (see
Paragraph 189).
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evidence the guideline group was not able to develop a recommendation in relation to sleep disturbance due to wind turbine noise at night.”
243. The principal goal of this 181-page WHO document was “to provide recommendations for protecting human health from exposure to environmental noise originating from various sources: transportation (road traffic, railway and aircraft) noise, wind turbine noise and leisure noise.”345
244. Figure 9 shows the recommendations for wind turbine noise put forth by this intergovernmental body.
Figure 9. WHO recommendation for wind turbine noise (GDG=Guideline Development Group).346 Although not specifically indicated, the Lden metric implies the use of A-frequency weighting 347, 348, 349 (see Paragraph 66).
345 World Health Organization. (2018) Environmental Noise Guidelines for the European Region. Regional Office for Europe: Geneva. pp. xiii.
https://www.who.int/europe/publications/i/item/9789289053563
346 World Health Organization. (2018) Environmental Noise Guidelines for the European Region. Regional Office for Europe: Geneva. pp. xiii. https://www.who.int/europe/publications/i/item/9789289053563.
347 “When prominent low-frequency components are present, noise measures based on A-weighting are inappropriate”— World Health Organization. (1999) Guidelines for community noise. Stockholm University & Karolinska Institute: Stockholm, Sweden. pp. xiii. https://www.who.int/publications/i/item/a68672.
348 See Appendix 2—Physics of Acoustics: IV. Can infrasound and low frequency noise be measured in dBA?
349 See Appendix 2—Physics of Acoustics: VII. Why is a psychosomatic (nocebo) origin attributed to the effects of infrasound and low frequency noise?
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245. Curiously, a search of this document for the word ‘infrasound’ revealed one single instance, reproduced in Figure 10.
Figure 10. The only instance of the word ‘infrasound’ appeared within the context of the above paragraphs, under the sub-section heading of “Additional considerations or uncertainties.”350, 351
246. “Standard methods of measuring sound, most commonly including A-weighting, may not capture the low-frequency sound and amplitude modulation characteristic of wind turbine noise”—this assertion is referenced with the 2015 Expert Panel of the Council of Canadian Academies (see Paragraph 212).352
247. And yet, in 1999, the WHO already had much of this information (even though WPPs were not yet an issue at that time):
A noise measure based only on energy summation and expressed as the conventional equivalent measure, LAeq, is not enough to characterize most noise environments. It is equally important to measure the maximum values of noise fluctuations, preferably combined with a measure of the number of noise events. If the noise includes a large proportion of low-frequency components, still lower values than the guideline values below will be needed. When
350 World Health Organization. (2018) Environmental Noise Guidelines for the European Region. Regional Office for Europe: Geneva. pp. 85.
https://www.who.int/europe/publications/i/item/9789289053563.
351 Amplitude modulation is a technically incorrect, although commonly used, expression for the audible acoustic disturbances
associated with the “whooshing” and “swishing” sounds emanating from WPPs. The preponderance of attention given to this
audible disturbance [Institute of Acoustics (UK) Good Practice Guide to the Application of ETSU-R-97 for the Assessment and Rating of Wind Turbine Noise, 2013] further underlies the limited focus of acousticians and health professionals who restrict their study
of WPP acoustic disturbances exclusively to the audible range. See: Annex A—Technical Background for Laypersons, Section 3: II. Harmonic Analysis. Paragraphs 45 to 49, and Figure 15.
352 The Expert Panel on Wind Turbine Noise and Human Health, Council of Canadian Academies (2015) Understanding the evidence: wind turbine noise.
Council of Canadian Academies: Ottawa. pp. xiii-xviii. https://cca-reports.ca/wp-content/uploads/2018/10/windturbinenoisefullreporten.pdf.
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prominent low-frequency components are present, noise measures based on A-weighting are inappropriate.353 [Emphasis added.]
248. To finalize this section of the Letter, a final paragraph is transcribed, reiterating the acceptance, on behalf of NHS-Highland Public Health, of a Dose (in the form of Lden354) and a Response (in the form of annoyance, see Paragraphs 194 to 198) both of which are at odds with the foundational axioms of the Medical Sciences’ dose-response relationship:
“As detailed above, we have undertaken a review into the potential health effects of the noise from wind turbines. This review has identified that whilst much of the literature is more limited in both quality and quantity, it is recognized that exposure to excessive wind turbine noise can impact on health through that of annoyance. Having said this, it is acknowledged that other factors can also play a contributory part in this over and above that of exposure to noise alone. In order to reduce potential impacts on health the noise levels produced by wind turbines should be below 45 dB Lden.”
8. The Diagnosis, or Rather, the Misdiagnosis
I. “This is a commonly recognized phenomenon”
249. IARO scientists are often duty-bound to point out the more absurd statements that are generally contained in these types of documents, particularly those emanating from acousticians.
250. But here, a didactic stance355 must be maintained considering that:
a. The signatory of this Letter is a medical professional, representing the position of NHS-Highland on this matter, and
b. The authors of this IARO Health Report are vigorously attempting to make this document an educational tool, for the benefit of the Scottish citizen.
251. To that end, the final paragraphs of the Letter will now be scrutinized:
353 World Health Organization. (1999) Guidelines for community noise. Stockholm University & Karolinska Institute: Stockholm, Sweden. pp. xiii.
https://www.who.int/publications/i/item/a68672.
354 For a brief description of Lden, see Table 1—Acronyms and variables used in this IARO Health Report.
355 As laid out in Paragraphs 37 and 40, a comprehensive approach is being taken by IARO scientists with this Health Report to
educate and inform NHS-Highland medical staff, for the benefit of the Scottish Citizen.
The Acoustic Impact of Wind Power Plants on Neighbouring Residents
A Scientific Response to Section 4.6 “Impact on Human Health and Well-Being”, Subsection 4.6.1 “Noise”, as submitted in the Report on Phase 1 of “Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnu Municipality”, Estonia (Job No. 2021-256, September 2024).
Document IARO25-1
January 2025
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International Acoustics Research Organization
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International Acoustics Research Organization
IARO is an international group of researchers with a mission to investigate acoustical environments, especially with respect to features that affect humans and animals, and to publish the results. IARO holds the ethics approval for the CSI-ACHE, the Citizen Science Initiative into Acoustical Characterisation of Human Environments, the results of which are publicly disseminated.
Contacts:
IARO, 37 Weston Ave, Palmerston North, 4414, New Zealand
Tel: +64 21 033 6528
Email: [email protected]
Authors of this Report (alphabetical)
Mariana Alves-Pereira, Ph.D., Lusófona University, Lisbon, Portugal
Huub Bakker, Ph.D., IARO, Palmerston North, New Zealand
Paulo Pereira-Sousa, University of Porto, Portugal
Rachel Summers, IARO, Palmerston North, New Zealand
Acknowledgements
The authors of this report would like to acknowledge the longstanding assistance of Dr Bruce Rapley of Sound Analytics for development of the SAM technology that generated all the recordings used to create this report. The authors would also like to acknowledge the many insights provided by Les Huson of L Huson & Associates and the vast experience in acoustics made available by Dr Philip Dickinson, Senior Researcher at IARO.
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CONTENTS
EXECUTIVE SUMMARY 4
A. INTRODUCTION 5 I. Background 5 II. Goal 5 III. Disclaimer 5 IV. International Acoustics Research Organization, IARO 6 V. Acronyms and Variables Used in IARO Reports 6
B. SUBSECTIONS 4.6.1–3 OF THE KOBRAS REPORT 7
C. WHAT DO NUMBERS EXPRESSED IN A-WEIGHTED DECIBELS MEAN? 8 I. Target Values 8 II. Target Values expressed in dBA 8
D. ANNOYANCE AND THE PURPOSE OF NOISE STANDARDS 12 I. Annoyance 12 II. Noise standards 13
E. NOISE FROM WIND POWER PLANTS 15 I. Audible Noise 15 II. Aerodynamic Noise 16 III. Wind Turbine Acoustic Signatures (WTAS) 19
F. BRIEF REVIEW OF THE HEALTH EFFECTS CAUSED BY EXPOSURE TO INFRASOUND AND LOW FREQUENCY NOISE 23
I. “What you can’t hear won’t hurt you” 23 II. Sources of Infrasound and Low Frequency Noise 24 III. Studies cited by the Kobras Report 27
G. CONCLUSIONS 29
H. RECOMMENDATIONS 30 I. Acoustics 30 II. Public Health 30 III. Livestock Health 31
ANNEX A: TRANSLATION IN ENGLISH OF SUBSECTION 4.6.1 OF THE KOBRAS REPORT
ANNEX B: EXCERPT FROM THE 2024 IARO ARNICLE HEALTH REPORT—CRITICAL ANALYSIS OF THE 2020 MAIJALA STUDY AND THE 2023 MARSHALL STUDY
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EXECUTIVE SUMMARY
1. In December 2024, IARO scientists were contacted by For Nature and People, based in Estonia, and were requested to provide a review of the Section 4.6 “Impact on Human Health and Well-Being”, Subsection 4.6.1 “Noise,” contained in “Report on Phase 1 of Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnu Municipality,” prepared by Kobras OÜ and submitted to the Local Government of the North-Pärnu, in Estonia.
2. The Kobras Report has followed the protocols stipulated by the Strategic Environmental Assessment (SEA) Directive, as required by EU standards.
3. By doing so, profound scientific flaws are introduced into the prediction of the impact of Wind Power Plants (WPPs) on the health and well-being of neighbouring residents and livestock.
4. These profound scientific flaws are ingrained into SEA protocols which, in turn, profoundly misinform, mislead and deceive governmental officials, decision-making hierarchies and the general public, regarding the health effects caused by the acoustic output of WPPs on neighbouring residents and livestock.
5. The scientific basis for the above statement is provided in this report with the aim of educating laypersons.
6. Computer modelling techniques for evaluating the noise emitted by WPPs only consider deafness as a consequence of exposure, because all numerical data is expressed in A- weighted decibels (dBA), meaning, only audible noise is considered.
7. The most important acoustic outputs of WPPs, which are harmful to human health, are contained within the infrasonic and lower frequency components of the acoustical spectrum (exposure to which does not cause deafness), and this is not taken into consideration by the computer modelling techniques, nor by SEA directives.
8. Recommendations are suggested for the second phase of this strategic planning project, assuming that the health of the general public and that of livestock are considered factors worth protecting.
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A. INTRODUCTION
I. Background
9. In December 2024, IARO scientists were contacted by For Nature and People [MTÜ Looduse ja Inimeste Eest], a not-for-profit organization based in Estonia. It was requested that IARO provide a review of the Section 4.6 “Impact on Human Health and Well-Being”, Subsection 4.6.1 “Noise,” contained in the Report prepared by Kobras OÜ and submitted to the Local Government of the North-Pärnu, in Estonia: “Report on Phase 1 of Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnu Municipality” [Põhja-Pärnumaa valla tuuleparkide eriplaneeringu asukoha eelvalik ja keskkonnamõju strateegilise hindamise I etapi aruanne] (Job No. 2021-256, September 2024).
10. The English translation of Subsection 4.6.1. of the above mentioned Kobras Report (pp. 146-162) that was received by IARO scientists, is provided in Annex A.
II. Goal
11. To provide a scientific review of Section 4.6.1 of the Kobras Report, regarding the acoustic output (i.e. noise) of wind power plants and its effects on human and animal health.
III. Disclaimer
a. The report provided herein has one, and only one, agenda; that of pure scientific inquiry.
b. The authors of this report are not party to anti-technology sentiments and do not harbour anti-wind-energy sentiments.
c. In no way can or should this scientific review be construed as a document arguing for or against the implementation of wind power plants, or any other type of infrastructure or industrial complexes that generate acoustic pollution.
d. IARO members and authors of this report hold no financial interest in the SAM Technology.
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IV. International Acoustics Research Organization, IARO
12. The International Acoustics Research Organization represents a group of scientists who, collectively, hold over 200 years of scientific experience in the field of infrasound and low frequency noise, and its effects of human health. Since 2016, IARO researchers have been recording and analysing acoustical data in and near homes located in the vicinity of onshore wind power plants, in the following countries (alphabetical): Australia, Canada, Denmark, England, France, Germany, Ireland, New Zealand, Northern Ireland, Portugal, Scotland, Slovenia, and The Netherlands. Prior to 2016, all IARO scientists were already working either in acoustics alone or in acoustics and health. All research conducted by IARO is part of the Citizen Science Initiative for Acoustic Characterization of Human Environments (CSI-ACHE).
V. Acronyms and Variables Used in IARO Reports
13. Table 1 lists the acronyms and variables used in IARO Reports.
Table 1. Acronyms and Variables that may appear in IARO Reports
dB Decibel unweighted (measure of sound pressure level) dBA Decibel A-weighted (measure of sound pressure level) Hz Hertz (measure of frequency)
ILFN Infrasound and Low Frequency Noise IWT Industrial Wind Turbine SEA Strategic Environmental Assessment SPL Sound Pressure Level
WHO World Health Organization WPP Wind Power Plant
WTAS Wind Turbine Acoustic Signature
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B. SUBSECTIONS 4.6.1–3 OF THE KOBRAS REPORT
14. Section 4 of the Kobras Report is dedicated to the Strategic Environmental Assessment (SEA), with Section 4.6 covering the overall “Impacts on Human Health and Well-Being”. This, in turn, is divided into Subsection 4.6.1, covering “Construction Noise,” Subsection 4.6.2 covering “Operational Noise,” and Subsection 4.6.3 covering “Low Frequency Noise.”
15. It is understood that:
a. The authors of the Kobras Report are constrained by the SEA protocols that have been previously established.
b. SEA protocols impose specific methodologies for the environmental assessment of this agent of disease, i.e., “noise.”
c. The authors of the Kobras Report have duly complied with SEA protocols.
d. The authors of Kobras Report may have limited knowledge regarding the type of “noise” emitted by Wind Power Plants (WPPs, also known as “wind farms”).
e. Even if the authors of the Kobras Report had proper scientific knowledge on acoustics in general, and on the acoustic output of WPPs in particular, they would be unable to implement this knowledge in their report, as it would be mostly incompatible with, and irrelevant to, SEA directives.
16. The dire consequence of this situation is that governmental officials, decision-making hierarchies and the general public are ill-informed and greatly misled regarding the noise output from WPPs and its effects on the surrounding human and animal populations.
17. It is the purpose of this IARO Report to scientifically inform governmental officials, decision-making hierarchies and the general public regarding the acoustic output of WPPs.
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C. WHAT DO NUMBERS EXPRESSED IN A-WEIGHTED DECIBELS MEAN?
I. Target Values
18. On page 147 of the Kobras Report, it is stated:
For residential areas, the noise limit value for industrial noise is 60 dBA during the day and 45 dBA at night. The target value is 50 dBA during the day and 40 dBA at night.
19. It is understood that these numerical values are imposed by pre-existing directives from the Estonian government, including a 2016 Supreme Court ruling demanding that WPPs comply with “target” values rather than with the Ministry of Environment’s noise limit values.
20. Scientifically, however, there are significant flaws with this type of noise characterization, and these become blatantly obvious (and a serious health concern) when WPPs are the noise source.
21. Since acoustics is a complex topic, IARO scientists have often used graphs to explain the meaning of these numerical values to laypersons (i.e., governmental officials, decision- making hierarchies and the general public). The same will be done here.
II. Target Values expressed in dBA
22. The “A” in the dBA metric refers to the application of the A frequency-weighting filter. This filter has been applied to the measurement of noise levels for almost a century because it simulates sensitivity of human hearing. When noise levels are measured directly, without A-weighting, they are expressed in dB units, and not in dBA units.1
1 For further understanding of this issue, please see: Alves-Pereira M, Rapley B, Bakker H, Summers R. (2019) Acoustics
and Biological Structures. In: Abiddine Fellah ZE, Ogam E. (Eds) Acoustics of Materials. IntechOpen: London. DOI: 10.5772/intechopen.82761.
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23. Figure 1 compares two acoustic environments, one with a measured value of 36 dBA and the other of 38 dBA, i.e., within the target value.2, 3
Figure 1. Frequency distribution of two acoustic environments, represented as 10-minute averages. Both were measured in the same location (see text) at different times of day: Environment A at 11:55H and Environment B at 17:05H. The last bar on the right side of either graph (in black circles) represent the overall noise level as expressed in dBA (red bar) and in dB unweighted (pink bar). The similarity of values when expressed in dBA leads most mainstream scientists to the belief that these are acoustically comparable environments. In reality, however, they are significantly different as shown by their sound levels in unweighted dB: 74 vs 58 dB.
2 The use of logarithm scale to define the acoustic decibel (referenced to 20 micropascal) means that the amplitude of
the sound doubles every 6 dB.
3 The acoustical data presented in this report are reproduced from a paper previously published in a Portuguese Technical Journal: Sousa-Pereira P, Bakker HHC, Alves-Pereira M. (2024) [The dose-response relationship in occupational noise exposures.] Revista Segurança, 271: 13-18. This work was awarded the best e-poster prize by the III Symposium on Occupational Health, organized by the School of Medicine of the University of Porto, Portugal (23 September 2024).
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24. Please note that these numerical values are based on field measurements, and not computer modelling techniques. The measurement location was in the animal shed of a livestock farm located near WPPs (For more information on this case, see4.).
25. Figure 2 is an educational representation of Figure 1, pointing out the portions of the graph that are relevant for understanding the matter at hand.
Figure 2. Educational representation of Figure 1, pointing out portions of the graph that are relevant for understanding the matter at hand. This is a representation of the distribution of acoustic energy over frequency in an environment, based on the average of a 10-minute measurement. Infrasound (below 20 Hz) and low frequency noise (20–200 Hz) correspond to the frequency ranges as indicated. The red bars indicate that noise level that is measured after the application of the A frequency-weighting filter (dBA), as required by legislation.5 The pink bars reflect the acoustical environment that is physically present, as measured with no filters applied (dB unweighted, or dB Linear, or dBZ), but this is not required by legislation.
4 Bakker HHC, Alves-Pereira M, Mann R, Summers R, Dickinson P. (2023) Infrasound exposure: High resolution
measurements near wind power plants. In: Suhanek M, Kevin Summers J. (Eds) Management of Noise Pollution. IntechOpen: London. DOI: 10.5772/intechopen.109047
5 Only the range 0.5–1000 Hz is shown here because above 1000 Hz, A-weighted sound levels and unweighted sound levels are essentially equal.
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26. As shown in Figure 1, when noise levels are measured after applying A-weighting, and expressed in dBA (red bars), a large portion of the soundscape is not taken into consideration (pink bars).
27. Mainstream scientists assume that “what you can’t hear won’t hurt you” (see Section F-I below), presuming that the only impact of sound on human health is mediated through auditory pathways and, therefore, the only health consequence is hearing impairment or deafness.
28. This (erroneous) notion justifies why a large portion of the soundscape (pink bars) is not considered within the context of human health.
29. Instead, this portion of the soundscape (pink bars) is considered inaudible to humans and, therefore, irrelevant to human health.
30. More importantly, Figure 1 shows that expressing noise levels in dBA does not differentiate between two, significantly different, acoustical environments (74 vs. 58 dB).
31. Therefore, determining a target value of 40 dBA for residential areas surrounding WPPs is merely protecting the human hearing function from becoming impaired due to continuous noise exposure.
32. The proposed target value will not protect any other aspect of human health with the exception of hearing impairment (See Section D-II below) and, possibly, speech intelligibility and overall auditory fatigue.
33. Establishing a target value of 40 dBA for residential areas surrounding WPPs does not guarantee the protection of health in human (and livestock) populations.
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D. ANNOYANCE AND THE PURPOSE OF NOISE STANDARDS
It should also be noted that there is a distinction between noise levels exceeding regulatory limits and noise levels causing annoyance. Noise standards are designed to ensure noise levels do not harm human health. This does not mean that the noise source will be inaudible. In the case of annoyance, the noise source is audible and may be unpleasant, but it does not constitute a health-threatening situation. The perceived annoyance of noise depends significantly on individual perception. Various studies have proposed 35 dB as the annoyance threshold for WPP noise (Schmidt et al., 2014). However, as mentioned, individual sensitivity to wind turbine noise varies. (Kobras Report, pp. 147)
I. Annoyance
34. The paragraph transcribed above illustrates a generalized idea which has practically zero scientific veracity, rendering it essentially irrelevant to the matter at hand.
35. “Annoyance” is not a scientifically valid medical or clinical endpoint.
36. In fact, the term “annoyance” does not appear in the 2017 edition of Mosby’s Medical Dictionary,6 nor does it appear in the 2018 edition of the Medical Dictionary published by the British Medical Association.7 In the 2020 edition of the Oxford Medical Dictionary, one single entry is found for this word:
Glare n. the undesirable effects of scattered stray light on the retina, causing reduced contrast and visual performance as well as annoyance and discomfort.8
37. In accordance with the World Health Organization (WHO):
An adverse effect of noise is defined as a change in the morphology and physiology of an organism that results in impairment of functional capacity, or an impairment of capacity to compensate for additional stress, or
6 O’Toole MT et al. (Eds). (2017) Mosby’s Medical Dictionary. 10th Ed. Elsevier: St Louis, MI, USA.
7 British Medical Association. (2018) Medical Dictionary. 4th Edition. Dorling Kindersley: London, UK.
8 Martin E, Law J. (Eds) (2020) Concise Colour Medical Dictionary. 7th Ed. Oxford University Press: Oxford, UK.
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increases the susceptibility of an organism to the harmful effects of other environmental influences.9
38. Clearly, the concept of “annoyance” does not comply with this WHO definition.
39. “The perceived annoyance of noise depends significantly on individual perception.” This is the classical definition of a subjective parameter.
40. Annoyance is commonly studied within the realm of Psychoacoustics, and not within the realm of Clinical/Medical Sciences, where objective medical endpoints are required to properly assess a medical situation.
41. “Individual sensitivity to wind turbine noise varies” because, individually, prior exposures to infrasound and low frequency noise (ILFN) also vary, oftentimes significantly.
42. Sensitivity to wind turbine noise increases with increasing exposures to (any type of) ILFN due to the physiological damage to the mechanisms involved in hearing. These prior exposures can be occupational, residential or recreational in nature. The time-profile over which these exposures occur are variable, depending on the nature and location of the source. For more detailed information on this topic, see 10,11,12.
II. Noise standards
43. “Noise standards are designed to ensure noise levels do not harm human health.” This is not entirely accurate.
44. Current noise standards in the European Union are designed to ensure that noise levels, ultimately, do not cause hearing impairment or deafness.
45. The assumption that these noise standards have been designed to protect “human health” is quite erroneous; they only protect human hearing and hearing-related issues.
9 World Health Organization. (1999) Guidelines for community noise. Stockholm University & Karolinska Institute:
Stockholm, Sweden. pp. 21. https://www.who.int/publications/i/item/a68672
10 IARO. (2024) Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland. Document No. IARO24-C1. Redacted version available at: IARO.org.nz.
11 Alves-Pereira M, Rapley B, Bakker H, Summers R. (2019) Acoustics and Biological Structures. In: Abiddine Fellah ZE, Ogam E. (Eds) Acoustics of Materials. IntechOpen: London. DOI: 10.5772/intechopen.82761.
12 Stepanov V. (2001) Biological effects of low frequency acoustic oscillations and their hygienic regulation. State Research Center of Russia, Moscow. https://archive.org/details/DTIC_ADA423963
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46. This is plainly visible in Figure 1. “Noise standards” only demand that the audible part of the acoustic environment be measured by mandating A-weighting (in dBA, red bars). All other possible impacts to human health via acoustical phenomena are ignored.
47. If “human health” had been a concern when designing these standards, infrasound and low frequency noise would not have been excluded from consideration, i.e., the pink bars in Figure1 would have been taken into account.
48. In the Russian Federation, for example, noise standards were indeed designed to protect human health because they also considered limiting values for infrasonic exposures, as shown in Figure 3.
Figure 3. Permissible exposure levels for infrasonic exposures in the Russian Federation.13 Notably, a) the infrasonic range has been segmented into one-octave bands at 2, 4, 8 and 16 Hz, each with different values for exposure limits, b) noise levels are expressed in dB “Lin,” meaning, unweighted dB, and c) permissible exposure levels are provided for two different types of occupational environments and two different types of environmental exposures.
49. Note that the numerical values shown in Figure 3 were established before the advent of WPPs, and therefore refer to tonal noise, and not pulsed trains of acoustic pressure waves, as are emitted from WPPs (See Section E-III below).
13 Reproduced from: Stepanov V. (2001) Biological effects of low frequency acoustic oscillations and their hygienic
regulation. State Research Center of Russia, Moscow. https://archive.org/details/DTIC_ADA423963
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E. NOISE FROM WIND POWER PLANTS
The noise sources in WPP’s can be divided into two categories:
-- Mechanical noise generated by the gearbox, motor, and other mechanisms of the wind turbine.
-- Aerodynamic noise created by the rotor blades moving through the air.
Modern wind turbines have been designed with considerable attention to noise reduction. Mechanical noise has been significantly minimized through the use of various insulation materials and technical solutions. Similarly, technical measures have been implemented to reduce aerodynamic noise. However, since these are large technical devices, some level of noise emission is inherent during the operation of wind turbines. (Kobras Report, pp. 146)
I. Audible Noise
50. “Mechanical noise,” as described above, usually occurs within the audible range. With the current noise standards (including tonal analyses), this category of acoustic disturbance can be mitigated or even eliminated in a relatively easy manner.
51. Computer modelling programs that are used worldwide for predicting the acoustic output of WPPs are based on the current noise standards. As has been shown, these do not protect human health, they merely protect human hearing.
52. All the images presented in the Kobras Report (Figure 76, pp. 153 through Figure 85, pp. 159) are based on this type of computer modelling.
53. The conclusion is, therefore, that none of these WPPs pose a risk for classical hearing impairment (as measured through audiograms) among the residents in the surrounding areas.
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II. Aerodynamic Noise
54. “Aerodynamic noise,” however, is an entirely different matter, because most of its acoustical energy resides in the infrasonic and lower-frequency part of the acoustic spectrum.14
55. Therefore, even when “technical measures [are] implemented to reduce aerodynamic noise,” these fall short of protecting the health of the general public.
The noise generated by turbines depends on wind strength. With weaker winds, the rotational speed of the turbine is lower, resulting in a lower noise level. As wind speed increases, the rotational speed rises, but natural ambient noise also increases, partially masking the turbine noise. (Kobras Report, pp. 147)
56. While wind speed is an obvious factor in the amount of aerodynamic noise produced by a rotating industrial wind turbine (IWT), blade size is another very important factor.
57. Aerodynamic noise is related to the amount of air that is pushed by the blade. The larger the area of the blade, the larger the amount of air that is displaced during rotation.
58. Therefore, the statement contained in the above-cited paragraph, “The noise generated by turbines depends on wind strength,” is incomplete. It depends on wind strength and blade size.
59. Regarding the last statement in the above paragraph, it is pertinent to transcribe the emails exchanged between RES (Renewable Energy Systems) and residents of Arnicle Farm in Argyle, Scotland, regarding the Blary Hill Wind Power Plant, owned and operated by RES, and installed in November/December 2021.15,16
60. On 14 June 2022, Arnicle Farm Resident (EM) questioned RES as to:
14 As the size of the wind turbine increases more and more of the sound energy moves to the lower-frequency and
infrasonic region.
15 IARO. (2024) Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland. Document No. IARO24-C1. Redacted version available at: IARO.org.nz.
16 IARO. (2023) Report on the High-Resolution Infrasonic and Low-Frequency Sound Recordings conducted at Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland in 2022 and 2023. Document No. IARO23-C1. Redacted version available at: IARO.org.nz.
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Why are the five turbines that are supposed to be stopped, turning slowly? We are experiencing more disturbance at Arnicle since they started, also disturbed sleep.17
61. Response from RES employee:
The turbines are currently under automatic curtailment. This automatic curtailment this [sic.] is below the normal speed of rotation and there will be no generation from the turbines. My colleagues continue to look into the issues you reported starting on Friday night and we will certainly investigate if anything has recently changed with the turbine operation, but I can’t see anything from the data I am looking at.18
62. Apparently, it is believed that “no generation” of electricity is synonymous with “no generation” of noise,19 not understanding that it is the displacement of air by rotating blades that is causing disturbance. Arnicle Farm Resident EM’s response less than one hour later:
Take my word for it, there is more disturbance here, my husband has just gone back to bed ......which is unheard of.......as he has had a very disturbed night and is exhausted.20
63. On 07 July 2022, Arnicle Farm Resident EM wrote to Argyll & Bute Council:
The disturbance from Blary Hill Windfarm is affecting us really badly since RES changed the front five turbines from being completely off to freewheeling. We have requested a few times that they keep them at a standstill, but they refuse saying that there is no change. (…) We are finding it very hard to carry on living at Arnicle and have to go away most days for a few hours to get some relief from the windfarm.21
64. On 27 September 2022, Arnicle Farm Resident (EM) again wrote to RES: “If today is a taste of what’s to come with all the turbines turning, you will drive us from our homes if this continues;”22 And again, on the following day:
17 Email from Arnicle Farm Resident (EM) to RES (MG) on 14 June 2022, at 10:31.
18 Email from RES (MG) to Arnicle Farm Resident (EM) on 14 June 2022, at 10:49.
19 This might even be true if only A-frequency weighted sound pressure levels were to be exclusively considered, see Figure 1.
20 Email from Arnicle Farm Resident (EM) to RES (MG) on 14 June 2022, at 11:24.
21 Email from Arnicle Farm Resident (EM) to Argyll & Bute Council (Senior Planning Officer AK) on 07 July 2022, at 15:12.
22 Email from Arnicle Farm Resident (EM) to RES (MG) on 27 September 2022, at 13:58.
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Why are you ignoring our request to monitor the low frequency noise, as that is what is causing the disturbance in the atmosphere at Arnicle not the audible noise that you are monitoring? 23
65. On 29 September 2022, RES insisted:
Our monitoring has shown a vast improvement in the noise performance of these turbines following this remedial work and we have decided to restart three machines so far.24
66. The response came from the husband of Arnicle Farm Resident (EM) and was unsurprising:
In reply to your email of 29th September I do not appreciate either myself or [EM] being called a liar.25
67. This short transcription of email exchanges shows the position taken by acousticians who are working for wind-industry related companies.
68. A “vast improvement of the noise performance” was considered to have occurred, but this appears to have translated into an aggravated acoustic disturbance for the residents.
69. This situation occurs because industry-employed acousticians, following legislated guidelines, base their noise levels solely on values expressed in dBA.
70. These acousticians, as well as the authors of the Kobras Report, are gravely misinformed on the topic of health and noise exposure.
71. The consequence of relying solely on SEA protocols for the evaluation of the acoustic output of WPPs is the severe health deterioration of human and animal populations that reside in the neighbouring areas.
The noise level is not directly dependent on the size of the turbine. Rather, for turbines with the same noise emission, the noise level reaching residential areas is somewhat lower for taller turbines, as the distance is greater. (Kobras Report, pp.148-9)
72. If this “noise level” refers to the audible noise, generated by gearboxes and mechanical components of the IWT, then, indeed, with taller IWT, these devices are theoretically (slightly) further away from residences.
23 Email from Arnicle Farm Resident (EM) to RES (MG) on 28 September 2022, at 15:43.
24 Email from RES (MG) to Arnicle Farm Resident (EM) on 29 September 2022 at 17:02.
25 Email from Arnicle Farm Resident (DM) to RES (MG) on 30 September 2022, at 09:27.
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73. If this “noise level” is supposed to refer to aerodynamic noise as well, then this statement is a profound scientific fallacy.
74. Not only do taller IWTs produce much more infrasonic energy, the taller the IWT, the further and stronger the infrasonic components will propagate.26
III. Wind Turbine Acoustic Signatures (WTAS)
75. Figure 1 is representative of the methodology imposed by legislation for the measurement of noise levels: temporal resolution of 10-minute averages, spectral resolution of 1/3rd of an octave, and sound pressure levels expressed in dBA.27
76. Scientists, however, are not constrained or restricted by these oversimplistic and antiquated methodologies.
77. Herein, acoustic environments are studied with a temporal resolution of 1 second and a spectral resolution of 1/36th of an octave.
78. For the layperson, one could say that IARO scientists are examining an acoustical environment with a microscope rather than a magnifying glass. That is, the resolution (temporal and spectral) is greatly increased.
79. Using new techniques to analyse recorded soundscapes,28 the significant differences detected in Environment A and Environment B (See Figure 1) become understandable.
80. Figure 4 shows the same frequency distribution in Environment A and Environment B, but with the above-mentioned increased spectral resolution: 1/36th of an octave instead of the 1/3rd of an octave as shown in Figure 1.
81. Figure 5 shows an educational representation of this same Figure 4.
26 Moller H, Pedersen CS. (2011) Low frequency noise from large wind turbines. Journal of the Acoustical Society of
America, 129(6):3727-44. doi: 10.1121/1.3543957.
27 It should be noted that these technical specifications are derived from the abilities of the best measuring instruments that existed almost a century ago.
28 Bakker HHC, Rapley BI, Summers SR, Alves-Pereira M, Dickinson PJ. (2017). An Affordable Recording Instrument for the Acoustical Characterisation of Human Environments. Paper presented at ICBEN-(International Commission for the Biological Effects of Noise)-2017, Zurich, Switzerland (Paper No. 3654). https://www.icben.org/2017/ICBEN%202017%20Papers/SubjectArea05_Bakker_P40_3654.pdf.
** The authors of this IARO Report hold no financial interest in the SAM technology.
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Figure 4. Frequency distribution of the same two environments shown in Figure 1, but with increased spectral resolution—1/36th of an octave instead of 1/3rd of an octave— and increased temporal resolution—1-second averages instead of 10-minute averages. Noticeably, Environment A presents with a series of peaks indicating a harmonic series (indicative of a train of pulses in the signal), while in Environment B this acoustic phenomenon is absent. It is pertinent to recall that both these environments have comparable “noise levels” as expressed in dBA (36 vs. 38 dBA) (See Figure 1).
82. It is pertinent to recall that the characterization of the two Environments, A and B, are the result of direct, scientific-grade field-measurements (not computer modelling) and
a. have similar noise levels as expressed in dBA (36 vs. 38 dBA),
b. have noise levels below the Target Value of 40 dBA, and,
c. are acoustically significantly different (74 vs. 58 dB-unweighted).
Figure 4 shows the presence of an acoustic phenomenon in Environment A which is absent in Environment B, namely, a train of pulses.
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Figure 5. Educational representation of Figure 3, pointing out portions of the graph that are relevant for understanding the matter at hand. This is the representation of the distribution of acoustic energy in an environment over frequency, based on the average of a 600-second (10- min) measurement. Infrasound (below 20 Hz) and low frequency noise (20–200 Hz) correspond to the frequency ranges as indicated. The noise level is expressed in dB on the Y axis. The red circle shows the spectral components of a train of pulses as a harmonic series with a fundamental frequency of 0.8 Hz, as indicated by the blue inverted triangles. They are generated by an IWT with a blade-pass frequency of 0.8 Hz.
83. For mathematical reasons, entirely explained in other scientific and peer-reviewed publications,29,30 these trains of pulses are representative of the acoustic output of IWTs, referred to as Wind Turbine Acoustic Signature (WTAS).
84. The existence of WTAS in Environment A is responsible for the significantly higher noise level in A (74 dB) when compared to Environment B (58 dB).
85. However, as can be seen in the comparative Figure 1, if the temporal and spectral resolution imposed by legislation is maintained—10-minute averages and 1/3rd octave
29 Bakker HHC, Alves-Pereira M, Mann R, Summers R, Dickinson P. (2023) Infrasound exposure: High resolution
measurements near wind power plants. In: Suhanek M, Kevin Summers J. (Eds) Management of Noise Pollution. IntechOpen: London. DOI: 10.5772/intechopen.109047,
30 Alves-Pereira M, Krough C, Bakker HHC, Summers R, Rapley B. (2019) Infrasound and low frequency noise guidelines – Antiquated and irrelevant for protecting populations. Proceedings of the 26th International Congress on Sound & Vibration, Montreal, Canada, July 7-11, No. 682. (Peer-Reviewed Conference Paper).
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band segmentation—then this type of information is not captured, and Environments A and B are (erroneously) considered comparable.
86. WTAS is deemed irrelevant to human health because it occurs, mainly, within the infrasonic range, which is considered to be inaudible to humans and, consequently, have no impact on human health.31
87. If WTASs are considered to be important enough to be quantified within the context of human health, the currently legislated noise-measurement methodologies would make this quantification impossible.
88. In a peer-reviewed scientific paper published in 2022, WTAS was specifically (strongly) correlated with sleep disturbance: When present the residents did not sleep, when absent they slept peacefully.32
31 Using ‘Light’ as an analogy, this is equivalent to believing that electromagnetic radiation that is not perceived through
the eyes (such as x-rays, microwaves, ultraviolet) are irrelevant to human health because they cannot be seen as light through the eyes. Moreover recent studies have shown that infrasonic signals can be processed by the brain but not conducted through the classical auditory pathways. See: Weichenberger M, Bauer M, Ku¨hler R, Hensel J, Forlim CG, Ihlenfeld A, et al. (2017) Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold: Evidence from fMRI. PLoS ONE, 12(4): e0174420. https://doi.org/10.1371/journal.pone.0174420.
32 Bakker HHC, Alves-Pereira M, Mann R, Summers R, Dickinson P. (2023) Infrasound exposure: High resolution measurements near wind power plants. In: Suhanek M, Kevin Summers J. (Eds) Management of Noise Pollution. IntechOpen: London. DOI: 10.5772/intechopen.109047,
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F. BRIEF REVIEW OF THE HEALTH EFFECTS CAUSED BY EXPOSURE TO INFRASOUND AND LOW
FREQUENCY NOISE
I. “What you can’t hear won’t hurt you”
The human hearing threshold begins at medium frequencies (500–4000 Hz) with a sound pressure level of 0–20 dB. For low-frequency ranges (0–200 Hz), the sound pressure must be significantly higher for the sound to be perceived—around 80 dB near 20 Hz and about 107 dB at 4 Hz. This principle must be considered when discussing the low-frequency noise impact of WPP’s. (Kobras Report, pp. 161)
89. There are several inaccuracies in the above paragraph, transcribed from the Kobras Report.
90. The most profound flaw is the assumption that health effects due to infrasound and low frequency noise exposures are only related to acoustic energy audible through the hearing function, i.e., “what you can’t hear won’t hurt you.”
91. This idea was shown to be a scientific fallacy as early as 1978, when it was proved that genetically deaf mice were greatly affected by infrasound exposures.33
92. More recently, it has been shown that the brain processes infrasound signals that are not relayed by the classical auditory pathways.34
93. The “principle [that] must be considered when discussing the low-frequency noise impact of WPP’s,” in the opinion of the authors of the Kobras Report is, in reality, a false issue.
94. Where WPPs are concerned, and contrary to the foundational precepts of Medical Sciences, great emphasis is placed on the question of perception or non-perception of
33 Busnel RG, Lehmann AG (1978). Infrasound and sound: Differentiation of their psychophysiological effects through
use of genetically deaf animals. Journal of the Acoustical Society of America, 63(3):974-977. https://pubmed.ncbi.nlm.nih.gov/670562/
34 Weichenberger M, Bauer M, Ku¨hler R, Hensel J, Forlim CG, Ihlenfeld A, et al. (2017) Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold: Evidence from fMRI. PLoS ONE, 12(4): e0174420. https://doi.org/10.1371/journal.pone.0174420.
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the “noise,” insinuating that, if the “noise” is not perceived through the auditory pathways, then it is not harmful.35
95. This notion is, of course, absurd (see Footnote 31).
96. Therefore, while the statement “For low-frequency ranges (0–200 Hz), the sound pressure must be significantly higher for the sound to be perceived—around 80 dB near 20 Hz and about 107 dB at 4 Hz” may be true, it has no relevance to health effects other than the hearing function.
II. Sources of Infrasound and Low Frequency Noise
Low-frequency components are present in most sounds, caused by both human-made sources (e.g., traffic) and natural sources (e.g., wind). For low- frequency sound to be disruptive or harmful to health, its sound pressure level is crucial. (Kobras Report, pp. 161)
97. Here, again, several inaccuracies are insinuated.
98. While it is true that “[l]ow-frequency components are present in most sounds, caused by both human-made sources (e.g., traffic) and natural sources (e.g., wind),” it is misleading to insinuate that these sources are similar or comparable. Indeed, they are significantly different. “[M]ost sounds” do not contain pulse trains, or even tonality, in this range.
99. The time profile over which acoustic events occur is of fundamental importance to determine health effects caused by this type of physical agent of disease (noise)—not merely the average level of sound pressure.
100. When statements such as “[f]or low-frequency sound to be disruptive or harmful to health, its sound pressure level is crucial” are provided, it misleads government officials and laypersons into believing that the sound level pressure is the most important factor (if not the only one) that matters when evaluating the health effects of ILFN exposures.
101. As shown in Figure 1, the generally used sound pressure level (expressed in dBA), does not differentiate between two significantly different acoustic environments.
Wind turbines, like many other sound sources, produce low-frequency sounds. However, current measurements and studies conducted at WPP’s
35 The word noise is here presented with quotes due to semantics: If the acoustical event is non-audible to humans,
and noise is defined as unwanted sound, then the noise that can be perceived but not heard must be presented as “noise.”
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have not detected low-frequency sounds at levels where they would be audible or cause health effects. (Kobras Report, pp.161)
102. Here, again, the scientific fallacies are shown to be deeply ingrained into SEA protocols:
103. “Current measurements… have not detected low-frequency sounds at levels where they would be audible...” Again, classical audibility of sound is deemed to be all-important, to the exclusion of all else. It is insinuated that action is necessary if, and only if, the low- frequency sound measurements are at levels considered audible. This perpetuates the notion “what you can’t hear won’t hurt you.”
104. “Current measurements… have not detected low-frequency sounds at levels where they would…. cause health effects.” This is not a scientifically proven, or provable, statement. The fact that some studies have found no health effects cannot be taken to prove that no health effects exist, especially when other studies disagree. See Annex B for an example of this situation.
Studies to date indicate that the low-frequency sounds caused by wind turbines are at a level comparable to ordinary environmental background noise (Leventhall, 2006). (Kobras Report, pp.161)
105. The average level of sound pressure may be comparable to ordinary background noise when using analyses with a spectral resolution of 1/3rd of an octave and a temporal resolution of 10-minute averages and, under these circumstances, could mask any differences in the character of the noise.
106. Yet, this is an antiquated methodology that is still in practice today (as imposed by legislative documents and guidelines), even though technology and analytical techniques have existed for many decades that permit a more scientific analysis of acoustic environments, with higher resolution.
107. Figure 6 shows the same two environments, A and B, as in Figure 1 and Figure 4, but here the data is presented in the form of Sonograms. Spectral resolution is 1/36th of an octave while the temporal resolution is 1-second, for a duration of 600 seconds (10 minutes).
108. Figure 7 is an educational representation of Figure 6.
109. Figure 6 shows, in each successive second, what SPL (in unweighted dB, given by the colour-scale) was present at each 1/36th octave band of the frequency spectrum.
110. The difference between the environmental background noise with and without the presence of a WTAS can be seen by any layperson.
111. The train of pulses of the WTAS, seen as the peaks of a harmonic series, in Figure 4 are manifested as the unbroken, horizontal lines seen in the corresponding sonogram
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(Environment A). That is, the peaks of energy seen in Figure 4 are present in each successive second, creating the horizontal lines.
112. These horizontal lines are absent in Environment B, as can be seen in the corresponding sonogram.
Figure 6. Sonograms of Environment A (top) and Environment B (bottom). The significant difference between these two acoustical environments is visually evidenced.
113. With these types of scientific-grade analyses, where the observation of the acoustic environment is accomplished with a higher temporal and spectral resolution of measurements —from magnifying glass to microscope-—natural background noise can be clearly differentiated from human-made noise. Nature does not generally produce acoustic events in straight lines (harmonic series) over such an extended period of time.
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Figure 7. Educational representation of Figure 6, pointing out portions of the graph that are relevant for understanding the matter at hand. This is the representation of the frequency distribution of an environment, based on the average of a 600-second (10-min) measurement. The regions corresponding to Infrasound (below 20 Hz) and low frequency noise (20-200 Hz) are indicated. Examples of SPLs as read with the colour-coded scale are given.
III. Studies cited by the Kobras Report
114. The Kobras Report refers to two studies in order to substantiate their position that noise emanating from WPPs has no impact on health (unless it is audible).
115. These studies are:
a. Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki.36 (Kobras Report, pp. 161), and
b. Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised
36 https://julkaisut.valtioneuvosto.fi/handle/10024/162329
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Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10.37 (Kobras Report, pp. 162)
116. IARO scientists have already performed a critical analysis of these (and other) studies. Regrettably, in the opinion of IARO scientists, these two studies have profound methodological flaws which fully invalidate the reported conclusions.
117. In Annex B, an excerpt of the 2024 IARO Arnicle Health Report is provided, where the critical analyses of these two studies are put forth, and the reasons why their conclusions are not based on the foundational principles of the Scientific Method are explained.
37 https://pubmed.ncbi.nlm.nih.gov/36946580/
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G. CONCLUSIONS
118. It is fully recognized by IARO scientists that Governments worldwide have been informed of the perceived economic benefits that WPPs might bring to their nations.
119. As demonstrated herein, these perceived economic benefits are accompanied by a substantial cost that is associated with the significant reduction in the health of human and animal population living in and around the vicinity of WPPs.
120. The Kobras Report submitted to the local government officials in Estonia, because of its good compliance with SEA Directives, perpetuates flawed and archaic methodologies regarding noise assessments for the prevention of harmful effects to health.
121. These flawed and archaic methodologies are used to justify conclusions that are, oftentimes, outright scientific fallacies.
122. This is particularly true for the health impacts induced by the acoustic output of WPPs.
123. Because Subsection 4.6.1 of the Kobras Report appears to be in good compliance with Estonian governmental legislation and EU SEA Directives, it continues to propagate the scientific fallacy that “what you can’t hear, can’t hurt you.”
124. It is hoped that the relevant authorities and the general public will take the following Recommendations under consideration.
a.
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H. RECOMMENDATIONS
125. The Kobras Report states that a second phase for this project, proposing the installation of multiple WPPs throughout the Estonian countryside, might be undertaken.
126. If a second planning phase is undertaken, the following recommendations are suggested for decision-makers, governmental officials and the general public (as applicable):
I. Acoustics
127. Baseline noise recordings should be conducted prior to any initial construction of any WPP and must include the infrasonic region of the acoustic spectrum.
128. Analysis of these recordings must include low-resolution averages expressed in dB unweighted and must include high-resolution samples over the infrasonic and low- frequency regions.
129. This means that noise measurement protocols cannot be exclusively dictated by current legislation, but rather, by proper scientific practices.
130. These noise measurements cannot be substituted by computer modelling techniques.
131. After the installation of WPPs, these noise recordings and analyses should be regularly performed for a minimum of five years (assuming that all approved WPPs will be fully installed and operational within the next five years).
132. As the propagation of WTAS is directional, the recordings and analyses should include the full range of wind directions and weather conditions present over all seasons.
133. These actions should be taken under the auspices of the Estonian governmental agency responsible for Public Health. In their absence, these actions should be taken by individual citizens under Citizens’ Science Initiatives.
II. Public Health
134. Prior to the installation of any WPP, neighbouring residents (up to 20 km away from the proposed WPPs) should be interviewed to ascertain their a) extent of prior ILFN exposures, b) current clinical situation, and c) past medical histories.
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135. During and after the installation of WPPs, residents should be monitored as to pertinent and relevant clinical and reproductive outcomes (and not merely for subjective, psychoacoustic parameters) for a minimum of five years.
136. These actions should be taken under the auspices of the Estonian governmental agency responsible for Public Health. In their absence, these actions should be taken by individual citizens under Citizens’ Science Initiatives.
III. Livestock Health
137. Detailed reports should be prepared by livestock owners regarding mortality, birth rates and sickness among their animals before the installation of any WPP.
138. Monitoring of these parameters must be maintained for a minimum of 5 years after the installation of the WPPs.
139. These actions should be taken under the auspices of the Estonian governmental agency responsible for Animal & Livestock Health. In their absence, these actions should be taken by individual citizens, under Citizens’ Science Initiatives.
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Report on Phase 1 of Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnumaa Parish Prepared by Kobras OÜ in November 2024
Ordered by Local Government of Põhja-Pärnumaa Parish
Translated by NPO For Nature and People (MTÜ Looduse ja Inimeste Eest) with the assistance of AI translator (ChatGPT)
4.6 IMPACT ON HUMAN HEALTH AND WELL-BEING
4.6.1 Noise
Noise is an unpleasant, disturbing, or otherwise health- and well-being-damaging sound. It is one of the most common and significant factors that degrade the quality of the living environment. Noise affects health and well-being in various ways—it can interfere with or make working, communication, and resting difficult, cause permanent ear damage leading to hearing impairment, induce stress, or trigger various functional disorders. The transmission of noise to the affected object depends on wind speed and direction, air humidity, and thermal stratification. The propagation of sound waves in the near-ground atmospheric layer is significantly influenced by the terrain characteristics, particularly the nature of the surface— topography, vegetation, water bodies, and buildings.
4.6.1.1 Construction Noise
Noise associated with the construction of WPP’s is similar to that of typical construction activities. Considering that all potentially suitable areas are located at least 1 km away from the nearest residence, it is unlikely that significant construction-related noise disturbances will occur for people.
4.6.1.2 Operational Noise The noise sources in WPP’s can be divided into two categories:
• Mechanical noise generated by the gearbox, motor, and other mechanisms of the wind turbine.
• Aerodynamic noise created by the rotor blades moving through the air.
Modern wind turbines have been designed with considerable attention to noise reduction. Mechanical noise has been significantly minimized through the use of various insulation materials and technical solutions. Similarly, technical measures have been implemented to reduce aerodynamic noise. However, since these are large technical devices, some level of noise emission is inherent during the operation of wind turbines.
The assessment of operational noise from wind turbines was conducted based on the Atmospheric Air Protection Act and the Minister of the Environment Regulation No. 71 of 16 December 2016 on "Limit values for noise transmitted in ambient air and methods for measuring, determining, and assessing noise levels."
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Wind turbine noise is classified as industrial noise.
According to the Atmospheric Air Protection Act, the limit values for noise transmitted in ambient air are as follows:
1. Noise limit value – the maximum permissible noise level, exceeding which causes significant environmental disturbance and necessitates the implementation of noise reduction measures.
2. Target Noise Level – the maximum permitted noise level for areas designated under new general plans.
For residential areas, the noise limit value for industrial noise is 60 dBA during the day and 45 dBA at night. The target value is 50 dBA during the day and 40 dBA at night.
A newly planned area, as defined in Regulation No. 71, is a previously undeveloped noise-sensitive area located outside densely populated or compactly built-up areas. The Ministry of the Environment has provided guidance (Ministry of the Environment, 2021b) and positions (letter No. 7-15/21/3300- 2 dated 13.09.2021) recommending that WPP planning adhere to noise limit values. However, the Supreme Court has determined that WPP projects should comply with target values (referred to as "design values" in applicable legislation) (Supreme Court ruling No. 3-3-1-88-15, 2016).
Since wind turbines operate continuously, and their noise can be considered more disturbing than some other types of industrial noise, it is recommended that WPP plans and projects aim to achieve the nighttime target value of 40 dB in residential areas. This means that the total noise emitted by the entire WPP, not just an individual turbine, must not exceed 40 dB.
It is important to note that noise limit values apply to the average noise level during the day (7:00– 23:00) and night (23:00–7:00). However, noise assessments for WPP’s are based on worst-case scenarios, assuming turbines operate continuously.
It should also be noted that there is a distinction between noise levels exceeding regulatory limits and noise levels causing annoyance. Noise standards are designed to ensure noise levels do not harm human health. This does not mean that the noise source will be inaudible. In the case of annoyance, the noise source is audible and may be unpleasant, but it does not constitute a health-threatening situation. The perceived annoyance of noise depends significantly on individual perception. Various studies have proposed 35 dB as the annoyance threshold for WPP noise (Schmidt et al., 2014). However, as mentioned, individual sensitivity to wind turbine noise varies.
The noise generated by turbines depends on wind strength. With weaker winds, the rotational speed of the turbine is lower, resulting in a lower noise level. As wind speed increases, the rotational speed rises, but natural ambient noise also increases, partially masking the turbine noise.
For new plans, wind turbine noise is assessed through computational modeling. In this case, the specialized software WindPRO 3.6 was used. The calculations were based on the international standard ISO 9613-2: "Acoustics – Attenuation of sound propagation outdoors, Part 2: General method of calculation," which is the recommended industrial noise calculation method for European Union member states without national calculation methods (European Parliament and Council Directive 2002/49/EC, 25 June 2002, concerning the assessment and management of environmental noise). This standard is widely used for evaluating noise propagation from WPP’s globally.
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Estonia has not established detailed requirements for input parameters in wind turbine noise modeling. In this case, noise propagation was modeled under unfavorable conditions – with a tailwind maximally favorable for noise transmission in all directions. According to technical data from turbine manufacturers, turbine noise emission typically increases up to wind speeds of 7–8 m/s. Additionally, at wind speeds above 8 m/s, natural wind noise begins to mask turbine noise.
The WindPRO calculation software allows for noise propagation assessments at various wind speeds; in this study, the worst-case conditions were considered.
The worst-case wind speed was used, meaning that noise maps were presented for conditions where noise levels were at their maximum (the program's automatic "Highest noise value" setting was applied). Noise modeling was conducted at a height of 2 m above the ground (the standard "ear" height used in Estonia for creating national noise maps). The calculation grid resolution was set at 10 m.
The meteorological coefficient was set to 1, and the ground roughness factor was set to 0.5 for the entire area. The terrain data were imported into the model based on elevation data from the Estonian Land Board (5 m resolution digital elevation model). Atmospheric conditions were modeled using WindPro's default settings (temperature 10°C and 70% humidity).
Objects that could directly block noise propagation, such as trees and forest areas, were not considered in the modeling. Similarly, existing buildings were not designated in the program as noise-blocking objects. In reality, if forest patches or auxiliary buildings lie between turbines and receptors, the actual noise levels experienced will be lower than those shown in the calculations. Therefore, the daily noise levels caused by the turbines are expected to be lower than the modeling results.
Considering research findings that wind turbine noise is inherently more disturbing than, for example, traffic noise, and the fact that ISO 9613-2 is not explicitly designed for noise assessments over long distances, a conservative approach to WPP noise assessments is justified.
Noise maps were created to depict A-weighted equivalent sound pressure levels LpA,eq in decibels, presented in 5 dB noise intervals. Noise levels at specific residential areas within the affected zone were not calculated (no receptor points were assigned). A more detailed noise assessment for each residential area within the impact zone is appropriate for the next phase of the special plan (e.g., detailed design or construction project preparation), once specific turbine locations are known.
In collaboration with stakeholders, the maximum potential number of turbines and their locations in potentially suitable areas were forecasted (illustrations in Schemes 72–74) to conduct noise modeling. The maximum number of turbines for each area is provided in Table 12. The turbine locations at this pre-selection stage are illustrative and will be refined in the next phase of the special planning process (detailed design or construction project preparation).
The noise map was created for a scenario in which all suitable areas under the Põhja-Pärnumaa Parish special plan were developed, accounting for potential cumulative impacts.
As input for noise modeling, a theoretical wind turbine with an emitted noise level of 108 dB was used for potentially suitable areas under the special plan. According to the WindPro database, modern turbines generally do not emit such high noise levels; most turbine models have emitted noise levels between 105–107 dB. As an exception, for the area marked as No. 11 in Schemes 72 and 73, an
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emitted noise level of 106 dB was considered. The theoretical rotor diameter was assumed to be 180 m, and the tower height was 200 m.
The noise level is not directly dependent on the size of the turbine. Rather, for turbines with the same noise emission, the noise level reaching residential areas is somewhat lower for taller turbines, as the distance is greater.
Table 12. Allowed maximum amount of IWT’s on special planning suitable areas
Scheme 72. Number of wind turbines and their potential locations in the areas deemed suitable under the special plan.
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Scheme 73. Number of wind turbines and their potential locations in the areas deemed suitable under the special plan.
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Scheme 74. Number of wind turbines and their potential locations in the areas deemed suitable under the special plan. Additionally, a noise map was created for a scenario where, in addition to the areas planned under Põhja-Pärnumaa Parish special plan, the areas designated by the Tootsi Suursoo WPP thematic plan and the Tori Northern Area special plan, as well as the development areas P7, P9, P10, P11, and P25 from the Pärnu County Wind Energy Thematic Plan, are fully realized (see Scheme 75 and Table 13). For the Tori Northern Area special plan, theoretical turbines with a rotor diameter of 180 meters and a tower height of 200 meters were used in noise modeling. According to the Pärnu County Wind Energy Thematic Plan, the rotor diameter of turbines in development areas P7, P9, P10, P11, and P25 was set at 180 meters, with a tower height of 160 meters. For both plans, the noise emission of turbines was considered to be 108 dB(A). As an exception, for area P9, a noise level of 106.9 dB(A) was used, based on the detailed plans for the P9 and P10 WPP’s.
Regarding the Tootsi Suursoo WPP, it is known that Nordex turbines are planned to be used, with a rotor diameter of 163 meters and a height of 164 meters. The noise emission level of a Nordex turbine is 106.4 dB(A). The results of the noise modeling are presented in Appendix 3.
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Table 13. Basis for noise modelling based on the amount of IWT’s from other plannings Planeering – planning Tuulikute arv – Amount of IWT’s
Scheme 75. Locations of areas potentially suitable under the special plan, alongside other planned WPP areas within and near Põhja-Pärnumaa Parish. Results Noise modeling revealed that if all areas are developed to the maximum extent indicated in Table 12, the nighttime noise target value (40 dB) may potentially be exceeded (or reached) in residential areas surrounding potential suitable area no. 3 (see Scheme 76). For the other potential suitable areas (5, 7, 8, 9, 10, 11, and 12), no exceedance of the nighttime noise target value in residential areas was observed.
In this case, residential areas where the noise limit value is applied instead of the target value due to agreements with landowners were not considered in the analysis. For all areas, the nighttime noise limit value (45 dB) is ensured in residential areas.
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In the development of potential suitable area no. 3, the nighttime noise target value is exceeded (or reached) in 3 residential areas. Residential areas are defined as land designated for residential purposes and the yard areas of residences located on agricultural land.
In a scenario where all potential suitable areas within the Põhja-Pärnumaa Parish special plan are developed, cumulative noise effects occur between areas 10 and 12. The remaining areas are located sufficiently far apart to avoid cumulative noise impacts. Despite the cumulative effect between areas, the nighttime noise target value is not exceeded in residential areas.
Scheme 76. Noise propagation modeling results for Potentially Suitable Area 3 under the maximum development scenario of the WPP.
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Scheme 77. Noise propagation modeling results for Potentially Suitable Areas 5 and 11 under the maximum development scenario of the WPP.
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Scheme 78. Noise propagation modeling results for Potentially Suitable Area 7 under the maximum development scenario of the WPP.
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Scheme 79. Noise propagation modeling results for Potentially Suitable Area 8 under the maximum development scenario of the WPP.
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Scheme 80. Noise propagation modeling results for Potentially Suitable Area 9 under the maximum development scenario of the WPP.
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Scheme 81. Noise propagation modeling results for Potentially Suitable Areas 10 and 12 under the maximum development scenario of the WPP. A noise map was created for the scenario where, in addition to the areas planned under the Põhja- Pärnumaa Parish’s special plan, all other WPP areas planned within Põhja-Pärnumaa Parish and its vicinity are realized (Schemes 82–84). The map indicates two main regions where the cumulative impact of different plans worsens the noise situation: Tellissaare Bog and Pitsalu Village Area. In the Pitsalu Village area, cumulative impacts arise between potential suitable area 12 and development area P7 of the Pärnu County wind energy thematic plan, affecting approximately three residential areas (plots Anni (18801:003:0075), Annuse (18801:003:0136), and Liiva (18801:003:0021)).
In the Tellissaare Bog area, cumulative noise impacts occur between potential suitable areas 7 and 8 and development areas P9 and P10 of the Pärnu County wind energy thematic plan. When potential suitable area 7 and development area P10 are developed, the nighttime noise target value in Põhja- Pärnumaa Parish is exceeded for approximately five residential areas. Additionally, the combined impact of potential suitable area 8 and development area P9 results in the target value being exceeded for approximately two residential areas.
In such a case, the Kruse cadastral unit (93005:002:0103) may also experience an exceedance of the nighttime noise limit value applicable to residential land. Noise modeling results show that the 45 dB limit is barely met on the Kruse residential land area.
Exceeding the noise limit poses a risk to human health and constitutes a significant negative impact.
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Scheme 81. Noise propagation modeling results for Potentially Suitable Areas 10 and 12 under the maximum development scenario of the WPP.
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Scheme 82. Results of the cumulative noise modeling between the Potentially Suitable Areas of the Põhja-Pärnumaa Special Plan and WPP areas from other plans.
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Scheme 83. Results of the cumulative noise modeling between the Potentially Suitable Areas of the Põhja-Pärnumaa Special Plan and WPP areas from other plans.
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Scheme 84. Results of the cumulative noise modeling between the Potentially Suitable Areas of the Põhja-Pärnumaa Special Plan and WPP areas from other plans. When considering the noise modeling results, it is important to recognize that the modeling did not account for noise-dampening objects, including vegetation. Several potential areas in the special plan are located in forested regions, which means that, in reality, the noise levels caused by wind turbines in residential areas are lower than what is reflected on the noise maps. Additionally, the noise from wind turbines has been overestimated in the modeling process. The noise level near the closest noise-sensitive buildings largely depends on the placement of the turbines. For potential area 3, the residential areas where the nighttime target value is exceeded are marginally affected. Therefore, during the next phase of the special plan (preparation of a detailed solution or construction project), adjustments to the turbine locations can ensure compliance with the target value for these residential areas.
Since the turbine layout at the site pre-selection stage is indicative, a new noise level model must be conducted during the detailed solution or construction project phase of the special plan. This new modeling must be based on the actual planned turbine locations and the best available knowledge at the time regarding the calculation of wind turbine noise.
It must be ensured that only new (not used) turbines are utilized in the WPP’s. Additionally, the noise emissions of the turbines placed in the area must not exceed 108 dB, and for area 11, this limit is 106 dB. The turbine placement in the detailed solution or construction project of the special plan must be optimized to ensure that the nighttime target value for industrial noise is met on residential land, in accordance with the Minister of the Environment's regulation No. 71 of December 16, 2016.
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Exceptions include the Kruse cadastral unit (identifier: 93005:002:0103) in Vihtra village, Koiva (93002:004:0135) in Kadjaste village, and Uue-Auru (93002:004:0034) in Oriküla (Geoportal of the Land Board, December 16, 2022). For these cadastral units, the nighttime limit value for industrial noise must be ensured. The owners of the Koiva and Uue-Auru cadastral units are given their consent to Enefit Green, which is interested in developing area 11, to install wind turbines at distances of 800 meters and 600 meters from residential buildings located on the cadastral units (800 meters for the Koiva cadastral unit and 600 meters for the Uue-Auri cadastral unit).
6.1.3 Low-Frequency Noise
The human hearing threshold begins at medium frequencies (500–4000 Hz) with a sound pressure level of 0–20 dB. For low-frequency ranges (0–200 Hz), the sound pressure must be significantly higher for the sound to be perceived—around 80 dB near 20 Hz and about 107 dB at 4 Hz. This principle must be considered when discussing the low-frequency noise impact of WPP’s. Low- frequency components are present in most sounds, caused by both human-made sources (e.g., traffic) and natural sources (e.g., wind). For low-frequency sound to be disruptive or harmful to health, its sound pressure level is crucial.
Wind turbines, like many other sound sources, produce low-frequency sounds. However, current measurements and studies conducted at WPP’s have not detected low-frequency sounds at levels where they would be audible or cause health effects. Studies to date indicate that the low-frequency sounds caused by wind turbines are at a level comparable to ordinary environmental background noise (Leventhall, 2006).
Low-frequency noise has consistently been a significant topic concerning wind turbines, as noise propagation can cover a large area. During propagation, the normal and higher frequency components of sound attenuate faster in air than low-frequency components (Hansen et al., 2017).
One of the most comprehensive studies on low-frequency noise related to wind turbines was conducted in Finland and published in English in 2020 (Maijala et al., 2020). The study, commissioned by the Finnish government, was carried out by the VTT Technical Research Centre of Finland. It combined long-term measurements (308 days) of sound levels at WPPs, as well as hearing tests and surveys among residents living near WPPs. The aim was to determine the characteristics of low-frequency noise produced by turbines and its potential effects on humans.
The study was prompted by complaints from some residents near WPPs, who attributed health issues—particularly sleep disturbances—to the presence of turbines. According to the study, 5% of residents near WPPs included in the survey (so-called “symptomatic respondents”) associated their health problems with low-frequency noise from turbines. Most symptomatic respondents lived within 2.5 km of the WPP, which was defined as the near area in the study. Among these residents, 15% identified as symptomatic.
Measured low-frequency noise in WPP areas generally ranged between 0.1–1 Hz, which is below the human hearing threshold (16–20 Hz). The lower the sound frequency, the higher the sound pressure must be for the sound to be audible.
The study identified a new aspect: wind turbines can produce occasional low-frequency noise peaks (short bursts of sound pressure up to 102 dB). These peaks might theoretically be audible to some
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individuals. However, it could not be demonstrated that individuals who reported health effects attributed to wind turbines were better able to perceive low-frequency noise. Hearing tests attempted to detect nervous system responses to low-frequency noise among individuals reporting health problems, but no such connection was found.
No reactions in the nervous system or other physiological parameters of these individuals were observed when they were exposed to low-frequency noise from turbines.
The study also found that within a 1.5 km radius of a WPP, changes in the sound spectrum could be noted, resulting in a more “urban” profile—increasing the proportion of low-frequency noise in the frequency distribution. The resulting sound spectrum becomes very similar to that in urban environments.
The study concluded that low-frequency noise from wind turbines cannot be linked to the health effects reported by individuals. However, a hypothesis was raised that the fluctuation in the amplitude of the turbine sound could potentially be more significant than low-frequency noise itself. One of the most recent studies on turbine infrasound was published in 2023, which investigated the long-term impact of infrasound on human health. The Woolcock Institute of Medical Research in Australia studied how infrasound from wind turbines affected 37 healthy adults over a 72-hour period. During the experiment, participants were placed in a sleep laboratory where unique sounds were played to them, including infrasound levels that mimic the infrasound produced by wind turbines. A control group was also included in the study, which was not exposed to infrasound but was exposed to traffic noise. At the end of the three-day experiment, it was concluded that infrasound had no effect on various health indicators of the participants (e.g., sleep, blood pressure, balance, hearing, etc.) (Marshall et al., 2023).
The noise levels for low-frequency noise are set by the Minister of Social Affairs in Regulation No. 42 of 04.03.2002 "Noise Norms for Living and Recreation Areas, Residential Buildings, and Shared Buildings, and Methods for Measuring Noise Levels" (Annex, Table 14). The noise levels in the annex refer to the sound pressure levels for assessing the disturbance caused by low-frequency noise in living and sleeping areas of residential buildings, and equivalent spaces during the night. These are not outdoor norms, but rather those that apply inside buildings.
Tabel 14. Low frequency noise values inside living quarters.
1/3 oktaaviriba kesksagedus Hz – 1/3 of octave band center frequency.
Helirõhutase - SPL
In Estonia, there are no national guidelines on how to calculate the propagation of low-frequency noise from wind turbines and its compliance with the values applicable in indoor spaces. However, in Finland, such an assessment guideline exists (Ympäristöhallinnon Ohjeita 2, 2014). Based on
Translation in English of section 4.6.1 of the Kobras OÜ’s report
20 MTÜ Looduse ja Inimeste Eest
December 2024
low-frequency noise modeling for other WPPs using this guideline, it has been found that at a distance of 1 km from the wind turbines, residential areas are not expected to exceed the recommended low-frequency noise value in living spaces (LEMMA OÜ, 2022). In this case, the potentially suitable areas are located at least 1 km away from residential buildings, so it can be assumed that the low-frequency noise values in living spaces are ensured.
Annex 3
Special planning noise map of Põhja-Pärnumaa Parish.
Translation in English of section 4.6.1 of the Kobras OÜ’s report
21 MTÜ Looduse ja Inimeste Eest
December 2024
"Noise map for a theoretical scenario where the areas of Põhja-Pärnumaa Parish’s special plan (EP), Tootsi Suursoo WPP (TP), and the northern part of Tori's special plan (EP), as well as the development areas P7, P9, P10, P11, and P2 of the Pärnu County plan (MP), have been realized."
Põhja-Pärnumaal, 19. jaanuaril 2025
MTÜ Looduse ja Inimeste Eest
täiendav arvamus ja ettepanekud
„PÕHJA-PÄRNUMAA VALLA TUULEPARKIDE ERIPLANEERINGU ASUKOHA EELVALIK JA
KESKKONNAMÕJU STRATEEGILISE HINDAMISE I ETAPI ARUANNE (redaktsioon: november 2024)“
kohta
MTÜ Looduse ja Inimeste Eest („MTÜ“) leiab, et Põhja-Pärnumaa valla tuuleparkide eriplaneeringu
keskkonnamõju strateegilise hindamise I etapi aruandes („KSH aruanne“) viidatud uuringud ja
modelleeringud, mis käsitlevad müra, sh infraheli, on ebaadekvaatsed.
MTÜ on tellinud teadusliku eksperthinnangu (lisatud käesolevale täiendavale arvamusele), mis seab
kahtluse alla KSH aruandes refereeritud teadusuuringute – näiteks, Maijala (2020) ja Marshalli (2023)
uuringud – sobivuse tuuleelektrigeneraatorist („tuugen“) lähtuva müra tervisemõjude hindamiseks.
Samuti seab IARO eksperthinnang kahtluse alla müra, sh inframüra mõõtmise metoodika sobivuse
tuugenist lähtuva müra adekvaatseks mõõtmiseks.
Sellest tulenevalt leiab MTÜ, et KSH aruandes aluseks võetud teadusuuringud ei ole piisavad
tuvastamaks, et infraheli on ohutu inimestele ja loomadele.
MTÜ Looduse ja Inimeste Eest teeb ettepaneku peatada Põhja-Pärnumaa valla tuuleparkide
eriplaneering, kuni on veenvalt ja teaduspõhiselt tuvastatud, et tuuleparkidest tulenev infraheli on
inimesele ja loodusele täiesti ohutu, seda ka pikaajalise kokkupuute ehk tuulepargi mõjualas
elamise korral, ning järgida IARO soovitusi (IARO eksperthinnangu punktid 125–139).
Märkus:
MTÜ Looduse ja Inimeste Eest tellitud IARO eksperthinnang koos selle lisadega A ja B on MTÜ
Looduse ja Inimeste Eest intellektuaalomand. Seda tohib levitada ainult koos viitega
mittetulundusühingule Looduse ja Inimeste Eest.
Lugupidamisega,
Urmas Maranik
MTÜ Looduse ja Inimeste Eest
/allkirjastatud digitaalselt/
PÕHJA-PÄRNUMAA VALLAVALITSUS
Pärnu-Paide mnt 2 / Vändra alev / Põhja-Pärnumaa vald/ 87701 Pärnu maakond
+372 5333 8609 / [email protected] / http://www.pparnumaa.ee / registrikood 77000234 / SEB pank
EE111010220267487223, Swedbank EE162200221068426764
Terviseamet
kuupäev digitaalallkirjas nr 7-1/165
Selgituse küsimine
Põhja-Pärnumaa Vallavalitsuse menetluses on tuuleparkide eriplaneeringu asukoha
eelvaliku otsuste eelnõude ja keskkonnamõju strateegilise hindamise esimese etapi aruande
koostamine. Eriplaneeringu koostamise eesmärgiks on elektrienergia tootmiseks rajatavatele
tuuleparkidele ja selle toimimiseks vajalikule taristule sobivate arendusalade leidmine.
Eriplaneeringu avalikul väljapanekul esitati asukoha eelvaliku otsuste eelnõude ja
keskkonnamõju strateegilise hindamise esimese etapi aruande kohta arvamusi. Palume Teie
selgitust MTÜ Looduse ja Inimeste Eest poolt esitatud „Rahvusvahelise Akustiliste
Uuringute Organisatsiooni [International Acoustics Research Organization (IARO)]
teaduslik eksperthinnang“-le vastamisel.
• Palume selgitada, kas Eestis kehtivad normid kaitsevad ainult kuulmiskahjustuse
eest aga ei kaitse muude tervisehädade eest?
• Tuugenite tekitatava müra modelleerimisel peetakse kokkupuute tagajärjena silmas
vaid kuulmislangust, sest kõik arvandmed on esitatud A-kaalutud detsibellides
(dBA), mis tähendab, et vaadeldakse ainult kuuldavat müra. Miks kasutatakse
peamiselt A-korrektsiooni, kas seda võib pidada asjakohaseks lähenemiseks?
• Kas on teada, et Eestis kasutatav tuulikute müra hindamise metoodika on
tunnistatud ebakompetentseks?
• Kas esitatud arvamus on teaduslik ja omab sisulist mõju Eesti tuulikute müra mõju
hindamise praktikale?
• Kas KSH-s kasutatud müra mõju hindamise osas on vaja kasutatud metoodika osas
teha muudatusi?
Ootame Teie selgitusi, et arvamuse avaldajale vastata ja eriplaneeringu menetlusega jätkata.
Lugupidamisega
(allkirjastatud digitaalselt)
Madis Koit
vallavanem
Lisa: 7-1-1003-321.
2 (2)
Lisa: 321 lisa 15JAN25—ANNEX B—Excerpt from 2024 IARO Arnicle Health Report
Lisa: 321 lisa 15JAN25—MAP—Estonian Response Report
Lisa: 321 lisa 15JAN25—ANNEX A —English Translation of Kobras SEA Report –
Section 4-6-1—Noise
Lisa: 321 lisa IARO 2025-Jan- 15 aruanne PP valla EP KSH (2024- nov) kohta- kokkuvõte
Erich Palm
Annex B Excerpt from Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland, UK (IARO Document IARO24-C1, pp 59-71)
(Annexed to IARO Report No. IARO25-1)
The full Health Report is available at: IARO.org.nz
January 2025
Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland
Document IARO24-C1
June 2024
Page 2 of 162 International Acoustics Research Organization 37 Weston Ave, Palmerston North, New Zealand T +64 21 033 6528 http://IARO.org.nz
International Acoustics Research Organization
IARO is an international group of researchers with a mission to investigate acoustical environments, especially with respect to features that affect humans and animals, and to publish the results. IARO holds the ethics approval for the CSI-ACHE, the Citizen Science Initiative into Acoustical Characterisation of Human Environments, the results of which are publicly disseminated.
Contacts:
IARO, 37 Weston Ave, Palmerston North, 4414, New Zealand
Tel: +64 21 033 6528
Email: [email protected]
This Health Report accompanies the December 2023 IARO Report No. IARO23-C1—High- Resolution Infrasonic and Low-Frequency Sound Recordings conducted at Arnicle Farm, Glenbarr, Argyll, Scotland in 2022 and 2023.
IARO does not use generative language artificial intelligence tools to construct their reports.
Authors of this Report (alphabetical)
Mariana Alves-Pereira, Ph.D., Lusófona University, Lisbon, Portugal
Huub Bakker, Ph.D., IARO, Palmerston North, New Zealand
Susan Crosthwaite, Citizens’ Initiative UK, Scotland
Rachel Summers, IARO, Palmerston North, New Zealand
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CONTENTS
SYNOPSIS ................................................................................................................................................ 8
EXECUTIVE SUMMARY .................................................................................................................................. 9
A. INTRODUCTION .................................................................................................................................. 11 I. Goals of this IARO Health Report ............................................................................................................... 11 II. Disclaimer ................................................................................................................................................... 11 III. International Acoustics Research Organization, IARO ................................................................................ 12 IV. Ethics Approval ........................................................................................................................................... 12 V. Acronyms and Variables Used in this Report and Appendices ................................................................... 12
B. BACKGROUND ON ARNICLE FARM ...................................................................................................... 14 I. Arnicle Farm, Glenbarr, Tarbert, Scotland ................................................................................................. 14 II. Noise measurements at Arnicle Farm ........................................................................................................ 15 III. Medical issues among Arnicle Farm residents ........................................................................................... 16
C. RATIONALE FOR THE ORGANISATION OF THIS REPORT ....................................................................... 17 I. Prior assertions by NHS Consultants on the matter at hand ...................................................................... 17 II. NHS-Highland Letter dated 20 November 2023 ......................................................................................... 18 III. The mandatory requirement for an educational approach ....................................................................... 19
D. THE 20-NOV-2023 NHS LETTER TO ARNICLE FARM AS AN EDUCATIONAL TOOL ................................... 21 1. “Alleged Noise” .................................................................................................................................... 21
I. The “alleged noise” .................................................................................................................................... 21 II. Medical professionals and industry-employed acousticians ...................................................................... 25 III. ‘Dose’ in the Medical Sciences’ dose-response relationship ...................................................................... 26 IV. ‘Dose’ of infrasound and low frequency noise ........................................................................................... 27
2. The Measured ‘Dose’ at Arnicle Farm .................................................................................................... 30 I. Physical attributes of the Dose of the physical agent ................................................................................ 30 II. Quantifying WTAS to establish a measure of Dose .................................................................................... 33 III. Quantifying exposure time to the measured WTAS Dose .......................................................................... 34 IV. Cumulative exposures from multiple WPPs ............................................................................................... 36
3. "From a Health Perspective” ................................................................................................................. 38 I. “Excessive noise is increasingly recognised as a significant public health issue” ....................................... 38 II. Exposure time at Arnicle Farm ................................................................................................................... 41 III. “Relieving factors” ...................................................................................................................................... 42
4. “As described by the World Health Organization” ................................................................................. 44 5. The Expert Panel of the Council of Canadian Academies ....................................................................... 45
I. The Charter given to the Expert Panel ....................................................................................................... 45 II. ‘Dose’ according to the Expert Panel of the Council of Canadian Academies ............................................ 46 III. The ‘Response’ of the dose-response relationship according to the Expert Panel .................................... 53 IV. Summary of the results achieved by the Expert Panel of Council of Canadian Academies ....................... 56
6. Other studies cited in the Letter ............................................................................................................ 59 I. Immediate effects of infrasound exposure ................................................................................................ 60 II. The Government-Sponsored Finnish Study ................................................................................................ 64 III. Intuitive symptoms ..................................................................................................................................... 67
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7. 2018 WHO Guidelines for Environmental Noise ..................................................................................... 68 8. The Diagnosis, or Rather, the Misdiagnosis ............................................................................................ 71
I. “This is a commonly recognized phenomenon” ......................................................................................... 71 II. “Although there may not be any direct physical health effects” ............................................................... 72 III. The physical agent of disease that is dismissed, and then tries to emerge as a psychosocial factor ......... 73
9. Therapeutic course of action: “Mindfulness, Meditation and Cognitive Behavioural Therapy” ............... 73
E. FURTHER EDUCATIONAL EFFORTS TO AUGMENT NHS-HIGHLAND’S UNDERSTANDING OF THE CLINICAL SITUATION AT ARNICLE FARM ............................................................................................................ 76 I. The Onset of Symptoms ............................................................................................................................. 76 II. Prior noise-exposures and current exposure times ................................................................................... 79 III. Increased susceptibility to this agent of disease ........................................................................................ 81 IV. Animal Data ................................................................................................................................................ 83
F. DISCUSSION ....................................................................................................................................... 86 I. Changing a paradigm or recognizing the obvious? .................................................................................... 86 II. Arnicle Farm and Blary Hill ......................................................................................................................... 87 III. What to do? ................................................................................................................................................ 89
G. CONCLUSIONS .................................................................................................................................... 91
H. RECOMMENDATIONS ......................................................................................................................... 93
I. APPENDIX 1—MEDICAL SCIENCES ....................................................................................................... 94 I. What is a Physical Agent of Disease? ......................................................................................................... 94 II. What parameters are important when investigating the biological effects of exposures to physical
agents of disease? ...................................................................................................................................... 94 a. Exposure Times: ............................................................................................................................... 94 b. Cumulative Effects: .......................................................................................................................... 95 c. Recovery Times: ............................................................................................................................... 95
III. How are physical agents of disease quantified? ........................................................................................ 95 IV. How is noise quantified? ............................................................................................................................ 95 V. What is the difference between ‘noise’ and ‘vibration’? ........................................................................... 96 VI. What are Dose-Response relationships? .................................................................................................... 97 VII. How is Dose measured? ............................................................................................................................. 98 VIII. How is Response measured? ...................................................................................................................... 98 IX. Is annoyance a proper measure of Response for wind turbine noise exposure? ...................................... 99 X. How are control populations selected for noise studies? ........................................................................ 100 XI. What happens when control populations are incorrectly selected? ....................................................... 101
J. APPENDIX 2—PHYSICS OF ACOUSTICS .............................................................................................. 104 I. What is Sound? ......................................................................................................................................... 104 II. What is Infrasound and Low Frequency Noise? ....................................................................................... 106 III. Why is noise generally measured in dBA? ................................................................................................ 106 IV. Can infrasound and low frequency noise be measured in dBA? .............................................................. 108 V. Can infrasound and low frequency be measured in dBC or dBG? ............................................................ 110 VI. How are infrasound and low frequency noise properly quantified? ........................................................ 112 VII. Why is a psychosomatic (nocebo) origin attributed to the effects of infrasound and low frequency noise?
.................................................................................................................................................................. 113 VIII. What happens when people complain of infrasound and low frequency noise to industry-employed
acousticians? ............................................................................................................................................ 117
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K. APPENDIX 3—WIND TURBINE ACOUSTIC SIGNATURES ..................................................................... 119 I. What is a wind turbine acoustic signature? ............................................................................................. 119 II. How are wind turbine acoustic signatures measured? ............................................................................ 120 III. What are Harmonic Prominences? .......................................................................................................... 122 IV. How is Dose measured when the agent of disease is WTAS? .................................................................. 123 V. If each wind turbine model generates its own WTAS, what happens when there are more than one WPP
with different wind turbine models? ....................................................................................................... 124
L. APPENDIX 4—CLINICAL & BIOLOGICAL MATTERS ............................................................................. 127 1. Cellular and Tissue Biology .................................................................................................................. 127
I. What is the structure of a mammalian cell? ............................................................................................ 127 II. What is a cellular mechanoreceptor? ...................................................................................................... 130 III. Biological tissues are viscoelastic—What does this mean? ..................................................................... 131 IV. What are dermal mechano-receptors? .................................................................................................... 134 V. What is the Fascia? ................................................................................................................................... 135 VI. Is oxidative stress an important factor in infrasonic exposures? ............................................................. 137
2. The Brain and the Ear ........................................................................................................................... 139 I. What is the brainstem? ............................................................................................................................ 139 II. What is the respiratory drive or the hyperventilatory reflex? ................................................................. 140 III. How is the respiratory drive evaluated? .................................................................................................. 140 IV. Is the measure of the respiratory drive an appropriate Response for the dose-response relationship
when the Dose is an acoustic agent of disease? ...................................................................................... 140 V. Is there other evidence of brainstem lesions among infrasound and low frequency noise-exposed
persons? ................................................................................................................................................... 142 VI. Have other effects of infrasound on the brain been studied? ................................................................. 142 VII. Is there evidence of respiratory pathology among infrasound and low frequency noise-exposed persons?
.................................................................................................................................................................. 143 VIII. How does the ear process infrasonic information? ................................................................................. 145 IX. Why is the ear considered an ‘organ of alarm’? ...................................................................................... 146 X. Why is sleeping in this type of contaminated environment so detrimental to health? ........................... 148
3. Occupational and Residential Exposures .............................................................................................. 148 I. Why are occupational exposures important to understand environmental exposures? ......................... 148 II. What extra-auditory medical conditions do noise-exposed workers develop? ....................................... 149 III. Do the extra-auditory medical conditions seen in noise-exposed workers also emerge in residential
infrasonic exposures? ............................................................................................................................... 152 IV. What is pericardial thickening in noise-exposed persons? ...................................................................... 153 V. Can noise act as a genotoxic agent? ......................................................................................................... 157 VI. Are balance disturbances an example of extra-auditory medical conditions developed among noise-
exposed persons? ..................................................................................................................................... 159 VII. Are auto-immune disorders an example of extra-auditory medical conditions developed among noise-
exposed persons? ..................................................................................................................................... 161
ANNEX A: Technical Background for Laypersons ANNEX B1 through B6: Documentation.
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min averages), and the concomitant ill-chosen health endpoints (such as annoyance, salivary cortisol levels, hearing loss) as measures of health effects.
9 Research on long-term exposure to wind turbine noise would provide a better understanding of the causal associations between wind turbine noise exposure and certain adverse health effects. In theory, this would be true, but not if the same unscientific assumptions are maintained, if the same incomplete assessment of dose is continued, and if the same non-primary and subjective adverse health effects are chosen for investigation.
10 Technological development is unlikely to resolve, in the short term, the current issues related to perceived adverse health effects of wind turbine noise. “Perceived”? 296 (see Paragraphs 45, 57 and 58).
11 Impact assessments and community engagement provide communities with greater knowledge and control over wind energy projects and therefore help limit annoyance. Annoyance is here clearly implied to be a result of psychosocial factors, and it appears to be the only health endpoint that merits attention.
212. The work produced by the 2015 Expert Panel on Wind Turbine Noise and Health of the Council of Canadian Academies, and the conclusions at which it arrives, are only marginally relevant to the matter at hand.
6. Other studies cited in the Letter
The dearth of knowledge on the matter at hand continues to be demonstrated by the signatory of the Letter:
“In addition to the impacts of audible noise itself, the contribution from low frequency infrasound to health effects has also been postulated although findings from recent studies have suggested that this is not supported. 297,298 Similarly, Turunen et al. whilst unable to assess a causal relationship due to the
296 See Appendix 2—Physics of Acoustics: VII. Why is a psychosomatic (nocebo) origin attributed to the effects of infrasound and low frequency
noise?
297 Footnote 5 of the Letter. Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/ [website added]
298 Footnote 6 of the Letter. Maijala PP, Kurki I, Vainio L, Pakarinen S, Kuuramo C, et al. (2021) Annoyance, perception, and physiological effects of wind turbine infrasound. Journal of the Acoustical Society of America, 149(4): 2238-2248. https://pubmed.ncbi.nlm.nih.gov/33940893/ [website added]
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cross-sectional nature of the study, suggested that interpretations of symptoms are affected by other factors in addition to the actual exposure.299”
213. For educational purposes,300 a brief review is conducted of the three studies cited above by the NHS-Highland medical representative.
I. Immediate effects of infrasound exposure
214. In the 2023 study by Marshall et al.,301, 302 the objective is stated as follows:
We aimed to test the effects of 72 h of infrasound (1.6–20 Hz at a sound level of ∼ 90 dB pk re 20 microPa, [303 , 304 ] simulating a wind turbine infrasound signature) exposure on human physiology, particularly sleep.
215. In Medical Sciences, this type of study purports to investigate the immediate effects of exposure, as opposed to long-term effects:
Our principal hypothesis was that exposure to infrasound in healthy individuals, at a level of ∼ 90 dB pk re 20 microPa compared with the sham infrasound, increases WASO [305] —a measure of sleep disturbance—and worsens other measures of sleep quality, mood, WTS [306] symptoms, and other electrophysio- logical measures. In addition, as a positive control, we also tested whether audible traffic noise, a mixture of road (motorbike, truck, car) and aircraft noise
299 Footnote 7 of the Letter. Turunen AW, Tittanen P, Yli-Tuomi T, Taimisto P, Lanki T. (2021) Symptoms intuitively associated with wind turbine infrasound.
Environmental Research, 192: 1-9. https://pubmed.ncbi.nlm.nih.gov/33131679/ [website added]
300 As indicated in Paragraphs 37 and 40, the primary reason for such a comprehensive approach to this IARO Health Report is to
provide an educational and instructive document for the NHS-Highland medical staff, with the ultimate purpose of benefiting
the Scottish Citizen.
301 Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/
302 Disclaimer included in the 2023 Marshall et al. paper: “All of the authors have superannuation accounts which are compulsory
in Australia and these accounts may contain investments in both traditional and renewable energy, including wind turbines.
R.T. is the founding principal of Renzo Tonin Associates who have previously worked as consultants for the NSW Department
of Planning on several wind farms in NSW, Australia. None of the investigators have any other pecuniary interest or academic
conflicts of interest in the outcomes of this study.“
303 See Appendix 1—Medical Sciences: IV. How is noise quantified?
304 See Appendix 2—Physics of Acoustics: I. What is Sound?
305 WASO = Wakefulness After Sleep Onset is the total number of minutes that an individual is awake after having initially fallen
asleep.
306 WTS = Wind Turbine Syndrome. See: Pierpont N. (2009) Wind Turbine Syndrome: A Report on a Natural Experiment. K-Selected Books: Santa Fe, New Mexico, USA. https://www.researchgate.net/publication/265247204_Wind_Turbine_Syndrome_A_Report_on_a_Natural_Experiment
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(at a sound level of 40–50 dB LAeq; night and 70 dB LAFmax transient maxima)
had an adverse impact on these same outcomes, when compared with sham infrasound.307
216. The conclusions of this study were:
Our study found no evidence that 72 h of exposure to a sound level of ∼ 90 dB pk re 20 microPa of simulated wind turbine infrasound in double-blind conditions perturbed any physiological or psychological variable. None of the 36 people exposed to infrasound developed what could be described as WTS. Our study is unique because it measured the effects of infrasound alone on sleep. This study suggests that the infrasound component of WTN [wind turbine noise] is unlikely to be a cause of ill-health or sleep disruption, although this observation should be independently replicated.
217. The dose presented to these subjects “simulating a wind turbine infrasound signature” was questioned by IARO scientists, and correspondence with co-author R. Tonin was exchanged (in May 2023) to ascertain what “simulated wind turbine infrasound” meant.
218. Regrettably, the material provided by co-author R. Tonin was regarded by IARO scientists as unsatisfactory, if “simulating a wind turbine infrasound signature” was the objective.308
219. Nevertheless, for the sake of scientific discussion, it will be temporarily accepted that the subjects of this study were actually presented with a properly simulated wind turbine infrasound signature.
307 Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind
Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/ [Footnotes contained in the original text are not included.]
308 The acoustic pattern used to simulate the wind turbine signal had a sawtooth profile, not the short-duration pulses of WTAS,
see Figure 3. A sawtooth-shaped wave has a quick onset, a slow decay, and only locally oscillates the air. WTAS has a rapid
onset and decay, and ‘pumps the air’ (as proposed by Dr Stephan Kaula, Germany), rather than only causing the local
oscillations that are typically seen in airborne, acoustic propagation phenomena.
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220. The idea seems to have been to investigate immediate responses to the simulated wind turbine infrasound signature, but as measured by parameters that, perhaps, were not so relevant for assessing immediate responses.309, 310, 311, 312, 313, 314, 315
221. Another questionable practice was the selection of the “healthy individuals” as study subjects. To the understanding of IARO scientists, no evaluation was made regarding prior exposures 316 to infrasound and low frequency noise.317, 318
222. Marshall et al. explain the viewpoint that foundationally justifies their study:
People who suffer from WTS [Wind Turbine Syndrome 319] report that their symptoms begin quickly when they are exposed to infrasound from wind turbines and are then sustained.[320] Our scientifically robust study provides evidence to address this claim. The Australian NHMRC [National Health and Medical Research Council] report that gave rise to our study made note of this “absence of evidence” rather than concluding an “evidence of absence” owing to the lack of any laboratory-controlled double-blind experiments of sufficient duration and intensity to hypothetically induce WTS in a human.321
309 See Appendix 4—Clinical & Biological Matters, Section 3-Occupational and Residential Exposures: I. Why are occupational exposures important
to understand environmental exposures?
310 See Appendix 4—Clinical & Biological Matters, Section 3-Occupational and Residential Exposures: II. What extra-auditory medical conditions do noise-exposed workers develop?
311 See Appendix 4—Clinical & Biological Matters, Section 3-Occupational and Residential Exposures: III. Do the extra-auditory medical conditions seen in noise-exposed workers also emerge in residential infrasonic exposures?
312 Mohr GC, Cole JJN, Guild E, von Gierke HE. (1965) Effects of low-frequency and infrasonic noise on man. Aerospace Medicine, 36: 817-24.
313 Ponomarkov VI, Tysik A, Kudryavtseva VI, Barer AS. (1969) Biological action of intense wide-band noise on animals. Problems of Space Biology NASA TT F-529, 7(May): 307-9.
314 Castelo Branco NAA, Gomes-Ferreira P, Monteiro E, Costa e Silva A, Reis Ferreira J, Alves-Pereira M. (2003) Respiratory epithelia in Wistar rats after 48 hours of continuous exposure to low frequency noise. Journal of Pneumology, formerly Revista Portuguesa Pneumologia, IX (6): 474-79. https://pubmed.ncbi.nlm.nih.gov/15190432/
315 Castelo Branco NAA, Reis Ferreira J, Alves-Pereira M. (2007). Respiratory pathology in vibroacoustic disease: 25 years of research. Journal of
Pneumology, formerly Revista Portuguesa Pneumologia, XIII (1): 129-135. https://pubmed.ncbi.nlm.nih.gov/17315094/
316 Including, foetal, childhood and young adult exposures in residential, occupational, and leisurely settings. See Appendix 1— Medical Sciences: II. What parameters are important when investigating the biological effects of exposures to physical agents of disease.
317 See Appendix 1—Medical Sciences: X. How are control populations selected for noise studies.
318 See Appendix 1—Medical Sciences: XI. What happens when control populations are incorrectly selected?
319 Pierpont N. (2009) Wind Turbine Syndrome: A Report on a Natural Experiment. K-Selected Books: Santa Fe, New Mexico, USA. https://www.researchgate.net/publication/265247204_Wind_Turbine_Syndrome_A_Report_on_a_Natural_Experiment
320 See Appendix 4—Clinical & Biological Matters, Section 1-Cellular and Tissue Biology. III. Biological tissues are viscoelastic—What does this mean?
321 Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/ [Footnotes contained in the original text are not included.]
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223. “Induce WTS in a human”? 322 As far as is understood by IARO scientists, WTS is not commonly viewed as an immediate effect of the exposure to this agent of disease.323
224. The expression “laboratory-controlled double-blind experiments of sufficient duration and intensity” as applied to the matter at hand is simultaneously unethical, dangerous, and unnecessary.324, 325
225. Is it the desire of the Australian NHMRC to expose subjects to a toxic agent—which is very difficult, if not impossible, to reproduce in laboratory settings—until some clearly severe health endpoint is observed? While tens of thousands of citizens are sitting in real- life laboratories being ‘accused’ of developing psychosomatic disorders? 326
226. This methodology is considered by IARO scientists to reflect sub-standard practices of Scientific Inquiry.
227. In conclusion, in the opinion of IARO scientists, the effort expended by these authors to conduct this study is laudable (particularly given the position of the Australian NHMRC), even though, scientifically, within the realm of Medical Sciences and dose-response relationships, its results are inconsequential.
322 “The causes of this syndrome have been the subject of substantial international controversy. Proponents have contended that the symptoms
that compose this syndrome are caused by low frequency subaudible infrasound generated by wind turbines. Critics have argued that these symptoms are psychological in origin and are attributable to nocebo effects. The Australian National Health and Medical Research Council Wind Farms and Human Health Reference Group concluded that the available evidence was not sufficient to establish which, if either, of these explanations is correct.” See: Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10. https://pubmed.ncbi.nlm.nih.gov/36946580/
323 Pierpont N. (2009) Wind Turbine Syndrome: A Report on a Natural Experiment. K-Selected Books: Santa Fe, New Mexico, USA. https://www.researchgate.net/publication/265247204_Wind_Turbine_Syndrome_A_Report_on_a_Natural_Experiment
324 What kind of “laboratory-controlled double-blind experiments of sufficient duration and intensity” were conducted for asbestos
contamination leading to asbestosis? Or for issues related to second-hand smoking, use of glyphosates, etc?
325 Alves-Pereira M, Rapley B, Bakker H, Summers R. (2019) Acoustics and Biological Structures. In: Abiddine Fellah ZE, Ogam E. (Eds) Acoustics of
Materials. IntechOpen: London. DOI: 10.5772/intechopen.82761.
326 In the opinion of IARO scientists, had this study been performed on 3 groups of people, differentiated by the extent of their
prior exposures (mild, moderate, or extensive), and, abiding by appropriate selection criteria of the study population, then,
perhaps, statistically useful numbers could have been obtained, and scientifically useful results could have been achieved. The
inability to reproduce ‘wind turbine infrasound’ under laboratorial conditions, however, would still render this study as
irremediably flawed, while its overall design could be deemed ethically questionable.
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II. The Government-Sponsored Finnish Study
228. The 2021 study by Maijala et al.327 is based on the 169-page 2020 Governmental Report on a Research Project carried out by Maijala et al.328
229. The main objective was “to find out whether wind turbine infrasound has harmful effects on human health.”329
230. Table 3 lists the specific objectives of this 2020 Research Project.
Table 3. Specific objectives of the 2020 Research Project sponsored by the Government of Finland.330
A. To characterize wind turbine noise as an exposure
1 What are the full spectrum sound levels, down to 0.1 Hz, inside houses near the wind power plants?
2 What are the characteristics of the sound, both audible and inaudible infrasound?
B. To describe symptoms that are intuitively associated with infrasound from wind turbines, i.e., wind turbine infrasound related symptoms.
3 What is the prevalence of wind turbine infrasound related symptoms in the vicinity of wind power plants?
4 What factors are associated with wind turbine infrasound related symptoms?
C. To study how infrasound produced by wind turbines affects humans, in particular, perception, annoyance, and physiological responses
5 Can low-frequency and infrasound wind turbine noise be perceived at typical and at extreme noise levels?
327 Maijala PP, Kurki I, Vainio L, Pakarinen S, Kuuramo C, et al. (2021) Annoyance, perception, and physiological effects of wind turbine infrasound. Journal
of the Acoustical Society of America, 149(4): 2238-2248. https://pubmed.ncbi.nlm.nih.gov/33940893/
328 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. https://julkaisut.valtioneuvosto.fi/handle/10024/162329
329 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 6. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
330 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 6-7. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
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6 What is the dependence between the depth of amplitude modulation and annoyance at low frequencies?
7 Does infrasound increase reported annoyance and psychophysiological responses?
8 What is the reactivity of the autonomic nervous system (ANS) to audible wind turbine sounds and its infrasound?
9 Are individuals who attribute their symptoms to wind turbines more sensitive to infrasound? Are they more able to detect infrasound and do they experience more annoyance compared to controls?
231. Objectives A1 and A2 were accomplished, and Figure 7 shows a representative example of the identified ‘dose.’
Figure 7. Representative example of the noise characterization (Raahe, indoors, 600-second sample). 331 LZ levels refer to unweighted dB values. LG refers to G-weighted values.332 LA refers to A-weighted values. Maximum and minimum LZ values are shown as curves.
331 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 21. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
332 See Appendix 2—Physics of Acoustics: V. Can infrasound be measured in dBC or dBG?
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232. Figure 7 shows a one-third-octave-band segmentation of the acoustic spectrum (similar to that shown in Figure 2). The solid black curve (LZ max) shows the highest sound pressure levels measured in unweighted dB.
233. There is no cut-off of spectral data as was seen in Figure 6 (i.e., the lower limiting frequency is 0.1 Hz and not 10 Hz), but there is also no recognition of a “wind turbine infrasound signal” as in the previous Marshall et al. study (see Paragraph 214). It was however recognized that “the most important frequencies were less than 2 Hz.”333
234. Objectives B3 and B4 (see Table 3) were more difficult to achieve, as “infrasound related symptoms” were established by questionnaires and telephone calls. While these types of surveys may have a certain usefulness, their direct results cannot be considered as a measure of Response within the realm of the Medical Sciences’ dose-response relationship,334 nor as per the WHO definition of noise-induced adverse health effects (see Paragraph 189).
235. Furthermore, there seems to not have been any stratification of the study population regarding prior noise exposure histories.335
236. Objectives C5 through C9 used “provocation experiments” conducted in an “infrasound chamber” whereby “systematically selected samples from real wind turbine sounds from wind power plant areas where inhabitants report symptoms associated with wind turbine infrasound or sound were used as stimuli.”336
237. As with the study by Marshall et al. (Paragraphs 224 to 226), it is not entirely understood why there is a perceived need to subject individuals in laboratory to a potentially noxious agent (which is very difficult, if not impossible, to reproduce under laboratorial conditions), while tens of thousands of individuals are living in ‘real-life laboratories,’ awaiting an objective, clinical observational study on behalf of the competent authorities.337
333 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 77. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
334 See Appendix 1—Medical Sciences: VIII. How is ‘Response’ measured?
335 See Appendix 1—Medical Sciences: II. What parameters are important when investigating the biological effects of exposures to physical agents of disease?
336 Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the
Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki. pp. 36 and 40. https://julkaisut.valtioneuvosto.fi/handle/10024/162329.
337 Although it is unclear to IARO scientists who (or what agency) could be classified as ‘the competent authorities.’
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III. Intuitive symptoms
238. In the third study of this series, the goal of Turunen et al.338 was to assess “the prevalence and severity of these wind turbine infrasound related symptoms:”
No matter what the true cause for the symptoms is, it is clear that symptoms are real and lead to worry, decreased quality of life, and potentially further to deteriorated health. High prevalence of this kind of phenomenon could be a serious threat to public health. The aim of this questionnaire study was to describe symptoms intuitively associated with infrasound from wind turbines.339
239. The immense wealth of data collected by this team of scientists was used to establish the prevalence of these self-reported “intuitive symptoms” from individuals living at different distances from WPPs: ≤ 2.5 km, 2.5–5 km, 5–10 km, and 10–20 km.
240. Figure 8 provides interesting information on the variation of self-reported “intuitive symptoms” with respect to distance from the WPP.
338 Please note that the authors of this study are the same as those of the Finnish Governmental study by Maijala et al. (see
Paragraph 228), and the data collected through questionnaires and telephone calls in the Maijala et al. study are the same data
used in this study. See: Turunen AW, Tittanen P, Yli-Tuomi T, Taimisto P, Lanki T. (2021) Symptoms intuitively associated with wind turbine infrasound. Environmental Research, 192: 1-9. https://pubmed.ncbi.nlm.nih.gov/33131679/
339 Turunen AW, Tittanen P, Yli-Tuomi T, Taimisto P, Lanki T. (2021) Symptoms intuitively associated with wind turbine infrasound. Environmental Research, 192: 1-9. https://pubmed.ncbi.nlm.nih.gov/33131679/
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Figure 8. “Smoothed association between distance to the closest wind turbine and the probability (logit scale) of wind turbine infrasound related symptoms (n = 1301)” (Footnote 339).
241. “Intuitive symptoms”, however, cannot be considered a bona fide Response applicable to the Medical Sciences’ dose-response relationships 340, 341 (see Paragraph 189).
7. 2018 WHO Guidelines for Environmental Noise
242. Environmental Noise Guidelines for the European Region is a 2018 document published by the WHO and that was quoted in the Letter sent by the NHS-Highland medical representative:
“In 2018, the WHO published guidelines342 to provide recommendations for protecting human health from exposure to environmental noise originating from a variety of sources including that of wind turbines. The importance of complete health which encompasses mental and social well-being and not solely the absence of disease was acknowledged in the development of the guidelines. As such, impacts on well-being, self-reported sleep disturbance and long-term annoyance were also considered. The guidelines included conditional recommendations in relation to wind turbine noise due to the quality of evidence. For average noise exposure, the conditional recommendation was to reduce noise levels produced by wind turbines below 45 dB Lden [343] [see Paragraph 66] as wind turbine noise above this level is associated with adverse health effects, specifically that of annoyance [344]. It was noted that there could be an increased risk factor for annoyance below this noise exposure level but that the lack of evidence meant that it could not state whether there was an increased risk for other health outcomes below this level. Similarly, as a result of the low quantity and heterogeneous nature of the
340 See Appendix 1—Medical Sciences: VI. What are Dose-Response relationships?
341 See Appendix 1—Medical Sciences: VIII. How is ‘Response’ measured?
342 Footnote 8 of the Letter. World Health Organization, Regional Office for Europe. Environmental Noise Guidelines for the European Region. Geneva: World health Organization; 2022. [The publication date of the document with this title is 2018.] https://www.who.int/europe/publications/i/item/9789289053563 [website added]
343 For a brief description of Lden see Table 1—Acronyms and variables used in this IARO Health Report.
344 Annoyance cannot be considered an “adverse health effect” (Response) within the context of the Medical Sciences’ dose-
response relationship (see Paragraphs 194 to 198), nor under the WHO definition for noise-induced adverse health effect (see
Paragraph 189).
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evidence the guideline group was not able to develop a recommendation in relation to sleep disturbance due to wind turbine noise at night.”
243. The principal goal of this 181-page WHO document was “to provide recommendations for protecting human health from exposure to environmental noise originating from various sources: transportation (road traffic, railway and aircraft) noise, wind turbine noise and leisure noise.”345
244. Figure 9 shows the recommendations for wind turbine noise put forth by this intergovernmental body.
Figure 9. WHO recommendation for wind turbine noise (GDG=Guideline Development Group).346 Although not specifically indicated, the Lden metric implies the use of A-frequency weighting 347, 348, 349 (see Paragraph 66).
345 World Health Organization. (2018) Environmental Noise Guidelines for the European Region. Regional Office for Europe: Geneva. pp. xiii.
https://www.who.int/europe/publications/i/item/9789289053563
346 World Health Organization. (2018) Environmental Noise Guidelines for the European Region. Regional Office for Europe: Geneva. pp. xiii. https://www.who.int/europe/publications/i/item/9789289053563.
347 “When prominent low-frequency components are present, noise measures based on A-weighting are inappropriate”— World Health Organization. (1999) Guidelines for community noise. Stockholm University & Karolinska Institute: Stockholm, Sweden. pp. xiii. https://www.who.int/publications/i/item/a68672.
348 See Appendix 2—Physics of Acoustics: IV. Can infrasound and low frequency noise be measured in dBA?
349 See Appendix 2—Physics of Acoustics: VII. Why is a psychosomatic (nocebo) origin attributed to the effects of infrasound and low frequency noise?
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245. Curiously, a search of this document for the word ‘infrasound’ revealed one single instance, reproduced in Figure 10.
Figure 10. The only instance of the word ‘infrasound’ appeared within the context of the above paragraphs, under the sub-section heading of “Additional considerations or uncertainties.”350, 351
246. “Standard methods of measuring sound, most commonly including A-weighting, may not capture the low-frequency sound and amplitude modulation characteristic of wind turbine noise”—this assertion is referenced with the 2015 Expert Panel of the Council of Canadian Academies (see Paragraph 212).352
247. And yet, in 1999, the WHO already had much of this information (even though WPPs were not yet an issue at that time):
A noise measure based only on energy summation and expressed as the conventional equivalent measure, LAeq, is not enough to characterize most noise environments. It is equally important to measure the maximum values of noise fluctuations, preferably combined with a measure of the number of noise events. If the noise includes a large proportion of low-frequency components, still lower values than the guideline values below will be needed. When
350 World Health Organization. (2018) Environmental Noise Guidelines for the European Region. Regional Office for Europe: Geneva. pp. 85.
https://www.who.int/europe/publications/i/item/9789289053563.
351 Amplitude modulation is a technically incorrect, although commonly used, expression for the audible acoustic disturbances
associated with the “whooshing” and “swishing” sounds emanating from WPPs. The preponderance of attention given to this
audible disturbance [Institute of Acoustics (UK) Good Practice Guide to the Application of ETSU-R-97 for the Assessment and Rating of Wind Turbine Noise, 2013] further underlies the limited focus of acousticians and health professionals who restrict their study
of WPP acoustic disturbances exclusively to the audible range. See: Annex A—Technical Background for Laypersons, Section 3: II. Harmonic Analysis. Paragraphs 45 to 49, and Figure 15.
352 The Expert Panel on Wind Turbine Noise and Human Health, Council of Canadian Academies (2015) Understanding the evidence: wind turbine noise.
Council of Canadian Academies: Ottawa. pp. xiii-xviii. https://cca-reports.ca/wp-content/uploads/2018/10/windturbinenoisefullreporten.pdf.
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prominent low-frequency components are present, noise measures based on A-weighting are inappropriate.353 [Emphasis added.]
248. To finalize this section of the Letter, a final paragraph is transcribed, reiterating the acceptance, on behalf of NHS-Highland Public Health, of a Dose (in the form of Lden354) and a Response (in the form of annoyance, see Paragraphs 194 to 198) both of which are at odds with the foundational axioms of the Medical Sciences’ dose-response relationship:
“As detailed above, we have undertaken a review into the potential health effects of the noise from wind turbines. This review has identified that whilst much of the literature is more limited in both quality and quantity, it is recognized that exposure to excessive wind turbine noise can impact on health through that of annoyance. Having said this, it is acknowledged that other factors can also play a contributory part in this over and above that of exposure to noise alone. In order to reduce potential impacts on health the noise levels produced by wind turbines should be below 45 dB Lden.”
8. The Diagnosis, or Rather, the Misdiagnosis
I. “This is a commonly recognized phenomenon”
249. IARO scientists are often duty-bound to point out the more absurd statements that are generally contained in these types of documents, particularly those emanating from acousticians.
250. But here, a didactic stance355 must be maintained considering that:
a. The signatory of this Letter is a medical professional, representing the position of NHS-Highland on this matter, and
b. The authors of this IARO Health Report are vigorously attempting to make this document an educational tool, for the benefit of the Scottish citizen.
251. To that end, the final paragraphs of the Letter will now be scrutinized:
353 World Health Organization. (1999) Guidelines for community noise. Stockholm University & Karolinska Institute: Stockholm, Sweden. pp. xiii.
https://www.who.int/publications/i/item/a68672.
354 For a brief description of Lden, see Table 1—Acronyms and variables used in this IARO Health Report.
355 As laid out in Paragraphs 37 and 40, a comprehensive approach is being taken by IARO scientists with this Health Report to
educate and inform NHS-Highland medical staff, for the benefit of the Scottish Citizen.
The Acoustic Impact of Wind Power Plants on Neighbouring Residents
A Scientific Response to Section 4.6 “Impact on Human Health and Well-Being”, Subsection 4.6.1 “Noise”, as submitted in the Report on Phase 1 of “Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnu Municipality”, Estonia (Job No. 2021-256, September 2024).
Document IARO25-1
January 2025
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International Acoustics Research Organization
37 Weston Ave, Palmerston North, New Zealand T +64 21 033 6528 http://smart-technologies.co.nz
International Acoustics Research Organization
IARO is an international group of researchers with a mission to investigate acoustical environments, especially with respect to features that affect humans and animals, and to publish the results. IARO holds the ethics approval for the CSI-ACHE, the Citizen Science Initiative into Acoustical Characterisation of Human Environments, the results of which are publicly disseminated.
Contacts:
IARO, 37 Weston Ave, Palmerston North, 4414, New Zealand
Tel: +64 21 033 6528
Email: [email protected]
Authors of this Report (alphabetical)
Mariana Alves-Pereira, Ph.D., Lusófona University, Lisbon, Portugal
Huub Bakker, Ph.D., IARO, Palmerston North, New Zealand
Paulo Pereira-Sousa, University of Porto, Portugal
Rachel Summers, IARO, Palmerston North, New Zealand
Acknowledgements
The authors of this report would like to acknowledge the longstanding assistance of Dr Bruce Rapley of Sound Analytics for development of the SAM technology that generated all the recordings used to create this report. The authors would also like to acknowledge the many insights provided by Les Huson of L Huson & Associates and the vast experience in acoustics made available by Dr Philip Dickinson, Senior Researcher at IARO.
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CONTENTS
EXECUTIVE SUMMARY 4
A. INTRODUCTION 5 I. Background 5 II. Goal 5 III. Disclaimer 5 IV. International Acoustics Research Organization, IARO 6 V. Acronyms and Variables Used in IARO Reports 6
B. SUBSECTIONS 4.6.1–3 OF THE KOBRAS REPORT 7
C. WHAT DO NUMBERS EXPRESSED IN A-WEIGHTED DECIBELS MEAN? 8 I. Target Values 8 II. Target Values expressed in dBA 8
D. ANNOYANCE AND THE PURPOSE OF NOISE STANDARDS 12 I. Annoyance 12 II. Noise standards 13
E. NOISE FROM WIND POWER PLANTS 15 I. Audible Noise 15 II. Aerodynamic Noise 16 III. Wind Turbine Acoustic Signatures (WTAS) 19
F. BRIEF REVIEW OF THE HEALTH EFFECTS CAUSED BY EXPOSURE TO INFRASOUND AND LOW FREQUENCY NOISE 23
I. “What you can’t hear won’t hurt you” 23 II. Sources of Infrasound and Low Frequency Noise 24 III. Studies cited by the Kobras Report 27
G. CONCLUSIONS 29
H. RECOMMENDATIONS 30 I. Acoustics 30 II. Public Health 30 III. Livestock Health 31
ANNEX A: TRANSLATION IN ENGLISH OF SUBSECTION 4.6.1 OF THE KOBRAS REPORT
ANNEX B: EXCERPT FROM THE 2024 IARO ARNICLE HEALTH REPORT—CRITICAL ANALYSIS OF THE 2020 MAIJALA STUDY AND THE 2023 MARSHALL STUDY
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EXECUTIVE SUMMARY
1. In December 2024, IARO scientists were contacted by For Nature and People, based in Estonia, and were requested to provide a review of the Section 4.6 “Impact on Human Health and Well-Being”, Subsection 4.6.1 “Noise,” contained in “Report on Phase 1 of Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnu Municipality,” prepared by Kobras OÜ and submitted to the Local Government of the North-Pärnu, in Estonia.
2. The Kobras Report has followed the protocols stipulated by the Strategic Environmental Assessment (SEA) Directive, as required by EU standards.
3. By doing so, profound scientific flaws are introduced into the prediction of the impact of Wind Power Plants (WPPs) on the health and well-being of neighbouring residents and livestock.
4. These profound scientific flaws are ingrained into SEA protocols which, in turn, profoundly misinform, mislead and deceive governmental officials, decision-making hierarchies and the general public, regarding the health effects caused by the acoustic output of WPPs on neighbouring residents and livestock.
5. The scientific basis for the above statement is provided in this report with the aim of educating laypersons.
6. Computer modelling techniques for evaluating the noise emitted by WPPs only consider deafness as a consequence of exposure, because all numerical data is expressed in A- weighted decibels (dBA), meaning, only audible noise is considered.
7. The most important acoustic outputs of WPPs, which are harmful to human health, are contained within the infrasonic and lower frequency components of the acoustical spectrum (exposure to which does not cause deafness), and this is not taken into consideration by the computer modelling techniques, nor by SEA directives.
8. Recommendations are suggested for the second phase of this strategic planning project, assuming that the health of the general public and that of livestock are considered factors worth protecting.
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A. INTRODUCTION
I. Background
9. In December 2024, IARO scientists were contacted by For Nature and People [MTÜ Looduse ja Inimeste Eest], a not-for-profit organization based in Estonia. It was requested that IARO provide a review of the Section 4.6 “Impact on Human Health and Well-Being”, Subsection 4.6.1 “Noise,” contained in the Report prepared by Kobras OÜ and submitted to the Local Government of the North-Pärnu, in Estonia: “Report on Phase 1 of Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnu Municipality” [Põhja-Pärnumaa valla tuuleparkide eriplaneeringu asukoha eelvalik ja keskkonnamõju strateegilise hindamise I etapi aruanne] (Job No. 2021-256, September 2024).
10. The English translation of Subsection 4.6.1. of the above mentioned Kobras Report (pp. 146-162) that was received by IARO scientists, is provided in Annex A.
II. Goal
11. To provide a scientific review of Section 4.6.1 of the Kobras Report, regarding the acoustic output (i.e. noise) of wind power plants and its effects on human and animal health.
III. Disclaimer
a. The report provided herein has one, and only one, agenda; that of pure scientific inquiry.
b. The authors of this report are not party to anti-technology sentiments and do not harbour anti-wind-energy sentiments.
c. In no way can or should this scientific review be construed as a document arguing for or against the implementation of wind power plants, or any other type of infrastructure or industrial complexes that generate acoustic pollution.
d. IARO members and authors of this report hold no financial interest in the SAM Technology.
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IV. International Acoustics Research Organization, IARO
12. The International Acoustics Research Organization represents a group of scientists who, collectively, hold over 200 years of scientific experience in the field of infrasound and low frequency noise, and its effects of human health. Since 2016, IARO researchers have been recording and analysing acoustical data in and near homes located in the vicinity of onshore wind power plants, in the following countries (alphabetical): Australia, Canada, Denmark, England, France, Germany, Ireland, New Zealand, Northern Ireland, Portugal, Scotland, Slovenia, and The Netherlands. Prior to 2016, all IARO scientists were already working either in acoustics alone or in acoustics and health. All research conducted by IARO is part of the Citizen Science Initiative for Acoustic Characterization of Human Environments (CSI-ACHE).
V. Acronyms and Variables Used in IARO Reports
13. Table 1 lists the acronyms and variables used in IARO Reports.
Table 1. Acronyms and Variables that may appear in IARO Reports
dB Decibel unweighted (measure of sound pressure level) dBA Decibel A-weighted (measure of sound pressure level) Hz Hertz (measure of frequency)
ILFN Infrasound and Low Frequency Noise IWT Industrial Wind Turbine SEA Strategic Environmental Assessment SPL Sound Pressure Level
WHO World Health Organization WPP Wind Power Plant
WTAS Wind Turbine Acoustic Signature
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B. SUBSECTIONS 4.6.1–3 OF THE KOBRAS REPORT
14. Section 4 of the Kobras Report is dedicated to the Strategic Environmental Assessment (SEA), with Section 4.6 covering the overall “Impacts on Human Health and Well-Being”. This, in turn, is divided into Subsection 4.6.1, covering “Construction Noise,” Subsection 4.6.2 covering “Operational Noise,” and Subsection 4.6.3 covering “Low Frequency Noise.”
15. It is understood that:
a. The authors of the Kobras Report are constrained by the SEA protocols that have been previously established.
b. SEA protocols impose specific methodologies for the environmental assessment of this agent of disease, i.e., “noise.”
c. The authors of the Kobras Report have duly complied with SEA protocols.
d. The authors of Kobras Report may have limited knowledge regarding the type of “noise” emitted by Wind Power Plants (WPPs, also known as “wind farms”).
e. Even if the authors of the Kobras Report had proper scientific knowledge on acoustics in general, and on the acoustic output of WPPs in particular, they would be unable to implement this knowledge in their report, as it would be mostly incompatible with, and irrelevant to, SEA directives.
16. The dire consequence of this situation is that governmental officials, decision-making hierarchies and the general public are ill-informed and greatly misled regarding the noise output from WPPs and its effects on the surrounding human and animal populations.
17. It is the purpose of this IARO Report to scientifically inform governmental officials, decision-making hierarchies and the general public regarding the acoustic output of WPPs.
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C. WHAT DO NUMBERS EXPRESSED IN A-WEIGHTED DECIBELS MEAN?
I. Target Values
18. On page 147 of the Kobras Report, it is stated:
For residential areas, the noise limit value for industrial noise is 60 dBA during the day and 45 dBA at night. The target value is 50 dBA during the day and 40 dBA at night.
19. It is understood that these numerical values are imposed by pre-existing directives from the Estonian government, including a 2016 Supreme Court ruling demanding that WPPs comply with “target” values rather than with the Ministry of Environment’s noise limit values.
20. Scientifically, however, there are significant flaws with this type of noise characterization, and these become blatantly obvious (and a serious health concern) when WPPs are the noise source.
21. Since acoustics is a complex topic, IARO scientists have often used graphs to explain the meaning of these numerical values to laypersons (i.e., governmental officials, decision- making hierarchies and the general public). The same will be done here.
II. Target Values expressed in dBA
22. The “A” in the dBA metric refers to the application of the A frequency-weighting filter. This filter has been applied to the measurement of noise levels for almost a century because it simulates sensitivity of human hearing. When noise levels are measured directly, without A-weighting, they are expressed in dB units, and not in dBA units.1
1 For further understanding of this issue, please see: Alves-Pereira M, Rapley B, Bakker H, Summers R. (2019) Acoustics
and Biological Structures. In: Abiddine Fellah ZE, Ogam E. (Eds) Acoustics of Materials. IntechOpen: London. DOI: 10.5772/intechopen.82761.
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23. Figure 1 compares two acoustic environments, one with a measured value of 36 dBA and the other of 38 dBA, i.e., within the target value.2, 3
Figure 1. Frequency distribution of two acoustic environments, represented as 10-minute averages. Both were measured in the same location (see text) at different times of day: Environment A at 11:55H and Environment B at 17:05H. The last bar on the right side of either graph (in black circles) represent the overall noise level as expressed in dBA (red bar) and in dB unweighted (pink bar). The similarity of values when expressed in dBA leads most mainstream scientists to the belief that these are acoustically comparable environments. In reality, however, they are significantly different as shown by their sound levels in unweighted dB: 74 vs 58 dB.
2 The use of logarithm scale to define the acoustic decibel (referenced to 20 micropascal) means that the amplitude of
the sound doubles every 6 dB.
3 The acoustical data presented in this report are reproduced from a paper previously published in a Portuguese Technical Journal: Sousa-Pereira P, Bakker HHC, Alves-Pereira M. (2024) [The dose-response relationship in occupational noise exposures.] Revista Segurança, 271: 13-18. This work was awarded the best e-poster prize by the III Symposium on Occupational Health, organized by the School of Medicine of the University of Porto, Portugal (23 September 2024).
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24. Please note that these numerical values are based on field measurements, and not computer modelling techniques. The measurement location was in the animal shed of a livestock farm located near WPPs (For more information on this case, see4.).
25. Figure 2 is an educational representation of Figure 1, pointing out the portions of the graph that are relevant for understanding the matter at hand.
Figure 2. Educational representation of Figure 1, pointing out portions of the graph that are relevant for understanding the matter at hand. This is a representation of the distribution of acoustic energy over frequency in an environment, based on the average of a 10-minute measurement. Infrasound (below 20 Hz) and low frequency noise (20–200 Hz) correspond to the frequency ranges as indicated. The red bars indicate that noise level that is measured after the application of the A frequency-weighting filter (dBA), as required by legislation.5 The pink bars reflect the acoustical environment that is physically present, as measured with no filters applied (dB unweighted, or dB Linear, or dBZ), but this is not required by legislation.
4 Bakker HHC, Alves-Pereira M, Mann R, Summers R, Dickinson P. (2023) Infrasound exposure: High resolution
measurements near wind power plants. In: Suhanek M, Kevin Summers J. (Eds) Management of Noise Pollution. IntechOpen: London. DOI: 10.5772/intechopen.109047
5 Only the range 0.5–1000 Hz is shown here because above 1000 Hz, A-weighted sound levels and unweighted sound levels are essentially equal.
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26. As shown in Figure 1, when noise levels are measured after applying A-weighting, and expressed in dBA (red bars), a large portion of the soundscape is not taken into consideration (pink bars).
27. Mainstream scientists assume that “what you can’t hear won’t hurt you” (see Section F-I below), presuming that the only impact of sound on human health is mediated through auditory pathways and, therefore, the only health consequence is hearing impairment or deafness.
28. This (erroneous) notion justifies why a large portion of the soundscape (pink bars) is not considered within the context of human health.
29. Instead, this portion of the soundscape (pink bars) is considered inaudible to humans and, therefore, irrelevant to human health.
30. More importantly, Figure 1 shows that expressing noise levels in dBA does not differentiate between two, significantly different, acoustical environments (74 vs. 58 dB).
31. Therefore, determining a target value of 40 dBA for residential areas surrounding WPPs is merely protecting the human hearing function from becoming impaired due to continuous noise exposure.
32. The proposed target value will not protect any other aspect of human health with the exception of hearing impairment (See Section D-II below) and, possibly, speech intelligibility and overall auditory fatigue.
33. Establishing a target value of 40 dBA for residential areas surrounding WPPs does not guarantee the protection of health in human (and livestock) populations.
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D. ANNOYANCE AND THE PURPOSE OF NOISE STANDARDS
It should also be noted that there is a distinction between noise levels exceeding regulatory limits and noise levels causing annoyance. Noise standards are designed to ensure noise levels do not harm human health. This does not mean that the noise source will be inaudible. In the case of annoyance, the noise source is audible and may be unpleasant, but it does not constitute a health-threatening situation. The perceived annoyance of noise depends significantly on individual perception. Various studies have proposed 35 dB as the annoyance threshold for WPP noise (Schmidt et al., 2014). However, as mentioned, individual sensitivity to wind turbine noise varies. (Kobras Report, pp. 147)
I. Annoyance
34. The paragraph transcribed above illustrates a generalized idea which has practically zero scientific veracity, rendering it essentially irrelevant to the matter at hand.
35. “Annoyance” is not a scientifically valid medical or clinical endpoint.
36. In fact, the term “annoyance” does not appear in the 2017 edition of Mosby’s Medical Dictionary,6 nor does it appear in the 2018 edition of the Medical Dictionary published by the British Medical Association.7 In the 2020 edition of the Oxford Medical Dictionary, one single entry is found for this word:
Glare n. the undesirable effects of scattered stray light on the retina, causing reduced contrast and visual performance as well as annoyance and discomfort.8
37. In accordance with the World Health Organization (WHO):
An adverse effect of noise is defined as a change in the morphology and physiology of an organism that results in impairment of functional capacity, or an impairment of capacity to compensate for additional stress, or
6 O’Toole MT et al. (Eds). (2017) Mosby’s Medical Dictionary. 10th Ed. Elsevier: St Louis, MI, USA.
7 British Medical Association. (2018) Medical Dictionary. 4th Edition. Dorling Kindersley: London, UK.
8 Martin E, Law J. (Eds) (2020) Concise Colour Medical Dictionary. 7th Ed. Oxford University Press: Oxford, UK.
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increases the susceptibility of an organism to the harmful effects of other environmental influences.9
38. Clearly, the concept of “annoyance” does not comply with this WHO definition.
39. “The perceived annoyance of noise depends significantly on individual perception.” This is the classical definition of a subjective parameter.
40. Annoyance is commonly studied within the realm of Psychoacoustics, and not within the realm of Clinical/Medical Sciences, where objective medical endpoints are required to properly assess a medical situation.
41. “Individual sensitivity to wind turbine noise varies” because, individually, prior exposures to infrasound and low frequency noise (ILFN) also vary, oftentimes significantly.
42. Sensitivity to wind turbine noise increases with increasing exposures to (any type of) ILFN due to the physiological damage to the mechanisms involved in hearing. These prior exposures can be occupational, residential or recreational in nature. The time-profile over which these exposures occur are variable, depending on the nature and location of the source. For more detailed information on this topic, see 10,11,12.
II. Noise standards
43. “Noise standards are designed to ensure noise levels do not harm human health.” This is not entirely accurate.
44. Current noise standards in the European Union are designed to ensure that noise levels, ultimately, do not cause hearing impairment or deafness.
45. The assumption that these noise standards have been designed to protect “human health” is quite erroneous; they only protect human hearing and hearing-related issues.
9 World Health Organization. (1999) Guidelines for community noise. Stockholm University & Karolinska Institute:
Stockholm, Sweden. pp. 21. https://www.who.int/publications/i/item/a68672
10 IARO. (2024) Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland. Document No. IARO24-C1. Redacted version available at: IARO.org.nz.
11 Alves-Pereira M, Rapley B, Bakker H, Summers R. (2019) Acoustics and Biological Structures. In: Abiddine Fellah ZE, Ogam E. (Eds) Acoustics of Materials. IntechOpen: London. DOI: 10.5772/intechopen.82761.
12 Stepanov V. (2001) Biological effects of low frequency acoustic oscillations and their hygienic regulation. State Research Center of Russia, Moscow. https://archive.org/details/DTIC_ADA423963
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46. This is plainly visible in Figure 1. “Noise standards” only demand that the audible part of the acoustic environment be measured by mandating A-weighting (in dBA, red bars). All other possible impacts to human health via acoustical phenomena are ignored.
47. If “human health” had been a concern when designing these standards, infrasound and low frequency noise would not have been excluded from consideration, i.e., the pink bars in Figure1 would have been taken into account.
48. In the Russian Federation, for example, noise standards were indeed designed to protect human health because they also considered limiting values for infrasonic exposures, as shown in Figure 3.
Figure 3. Permissible exposure levels for infrasonic exposures in the Russian Federation.13 Notably, a) the infrasonic range has been segmented into one-octave bands at 2, 4, 8 and 16 Hz, each with different values for exposure limits, b) noise levels are expressed in dB “Lin,” meaning, unweighted dB, and c) permissible exposure levels are provided for two different types of occupational environments and two different types of environmental exposures.
49. Note that the numerical values shown in Figure 3 were established before the advent of WPPs, and therefore refer to tonal noise, and not pulsed trains of acoustic pressure waves, as are emitted from WPPs (See Section E-III below).
13 Reproduced from: Stepanov V. (2001) Biological effects of low frequency acoustic oscillations and their hygienic
regulation. State Research Center of Russia, Moscow. https://archive.org/details/DTIC_ADA423963
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E. NOISE FROM WIND POWER PLANTS
The noise sources in WPP’s can be divided into two categories:
-- Mechanical noise generated by the gearbox, motor, and other mechanisms of the wind turbine.
-- Aerodynamic noise created by the rotor blades moving through the air.
Modern wind turbines have been designed with considerable attention to noise reduction. Mechanical noise has been significantly minimized through the use of various insulation materials and technical solutions. Similarly, technical measures have been implemented to reduce aerodynamic noise. However, since these are large technical devices, some level of noise emission is inherent during the operation of wind turbines. (Kobras Report, pp. 146)
I. Audible Noise
50. “Mechanical noise,” as described above, usually occurs within the audible range. With the current noise standards (including tonal analyses), this category of acoustic disturbance can be mitigated or even eliminated in a relatively easy manner.
51. Computer modelling programs that are used worldwide for predicting the acoustic output of WPPs are based on the current noise standards. As has been shown, these do not protect human health, they merely protect human hearing.
52. All the images presented in the Kobras Report (Figure 76, pp. 153 through Figure 85, pp. 159) are based on this type of computer modelling.
53. The conclusion is, therefore, that none of these WPPs pose a risk for classical hearing impairment (as measured through audiograms) among the residents in the surrounding areas.
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II. Aerodynamic Noise
54. “Aerodynamic noise,” however, is an entirely different matter, because most of its acoustical energy resides in the infrasonic and lower-frequency part of the acoustic spectrum.14
55. Therefore, even when “technical measures [are] implemented to reduce aerodynamic noise,” these fall short of protecting the health of the general public.
The noise generated by turbines depends on wind strength. With weaker winds, the rotational speed of the turbine is lower, resulting in a lower noise level. As wind speed increases, the rotational speed rises, but natural ambient noise also increases, partially masking the turbine noise. (Kobras Report, pp. 147)
56. While wind speed is an obvious factor in the amount of aerodynamic noise produced by a rotating industrial wind turbine (IWT), blade size is another very important factor.
57. Aerodynamic noise is related to the amount of air that is pushed by the blade. The larger the area of the blade, the larger the amount of air that is displaced during rotation.
58. Therefore, the statement contained in the above-cited paragraph, “The noise generated by turbines depends on wind strength,” is incomplete. It depends on wind strength and blade size.
59. Regarding the last statement in the above paragraph, it is pertinent to transcribe the emails exchanged between RES (Renewable Energy Systems) and residents of Arnicle Farm in Argyle, Scotland, regarding the Blary Hill Wind Power Plant, owned and operated by RES, and installed in November/December 2021.15,16
60. On 14 June 2022, Arnicle Farm Resident (EM) questioned RES as to:
14 As the size of the wind turbine increases more and more of the sound energy moves to the lower-frequency and
infrasonic region.
15 IARO. (2024) Health Report on Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland. Document No. IARO24-C1. Redacted version available at: IARO.org.nz.
16 IARO. (2023) Report on the High-Resolution Infrasonic and Low-Frequency Sound Recordings conducted at Arnicle Farm, Glenbarr, Tarbert, Argyll, Scotland in 2022 and 2023. Document No. IARO23-C1. Redacted version available at: IARO.org.nz.
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Why are the five turbines that are supposed to be stopped, turning slowly? We are experiencing more disturbance at Arnicle since they started, also disturbed sleep.17
61. Response from RES employee:
The turbines are currently under automatic curtailment. This automatic curtailment this [sic.] is below the normal speed of rotation and there will be no generation from the turbines. My colleagues continue to look into the issues you reported starting on Friday night and we will certainly investigate if anything has recently changed with the turbine operation, but I can’t see anything from the data I am looking at.18
62. Apparently, it is believed that “no generation” of electricity is synonymous with “no generation” of noise,19 not understanding that it is the displacement of air by rotating blades that is causing disturbance. Arnicle Farm Resident EM’s response less than one hour later:
Take my word for it, there is more disturbance here, my husband has just gone back to bed ......which is unheard of.......as he has had a very disturbed night and is exhausted.20
63. On 07 July 2022, Arnicle Farm Resident EM wrote to Argyll & Bute Council:
The disturbance from Blary Hill Windfarm is affecting us really badly since RES changed the front five turbines from being completely off to freewheeling. We have requested a few times that they keep them at a standstill, but they refuse saying that there is no change. (…) We are finding it very hard to carry on living at Arnicle and have to go away most days for a few hours to get some relief from the windfarm.21
64. On 27 September 2022, Arnicle Farm Resident (EM) again wrote to RES: “If today is a taste of what’s to come with all the turbines turning, you will drive us from our homes if this continues;”22 And again, on the following day:
17 Email from Arnicle Farm Resident (EM) to RES (MG) on 14 June 2022, at 10:31.
18 Email from RES (MG) to Arnicle Farm Resident (EM) on 14 June 2022, at 10:49.
19 This might even be true if only A-frequency weighted sound pressure levels were to be exclusively considered, see Figure 1.
20 Email from Arnicle Farm Resident (EM) to RES (MG) on 14 June 2022, at 11:24.
21 Email from Arnicle Farm Resident (EM) to Argyll & Bute Council (Senior Planning Officer AK) on 07 July 2022, at 15:12.
22 Email from Arnicle Farm Resident (EM) to RES (MG) on 27 September 2022, at 13:58.
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Why are you ignoring our request to monitor the low frequency noise, as that is what is causing the disturbance in the atmosphere at Arnicle not the audible noise that you are monitoring? 23
65. On 29 September 2022, RES insisted:
Our monitoring has shown a vast improvement in the noise performance of these turbines following this remedial work and we have decided to restart three machines so far.24
66. The response came from the husband of Arnicle Farm Resident (EM) and was unsurprising:
In reply to your email of 29th September I do not appreciate either myself or [EM] being called a liar.25
67. This short transcription of email exchanges shows the position taken by acousticians who are working for wind-industry related companies.
68. A “vast improvement of the noise performance” was considered to have occurred, but this appears to have translated into an aggravated acoustic disturbance for the residents.
69. This situation occurs because industry-employed acousticians, following legislated guidelines, base their noise levels solely on values expressed in dBA.
70. These acousticians, as well as the authors of the Kobras Report, are gravely misinformed on the topic of health and noise exposure.
71. The consequence of relying solely on SEA protocols for the evaluation of the acoustic output of WPPs is the severe health deterioration of human and animal populations that reside in the neighbouring areas.
The noise level is not directly dependent on the size of the turbine. Rather, for turbines with the same noise emission, the noise level reaching residential areas is somewhat lower for taller turbines, as the distance is greater. (Kobras Report, pp.148-9)
72. If this “noise level” refers to the audible noise, generated by gearboxes and mechanical components of the IWT, then, indeed, with taller IWT, these devices are theoretically (slightly) further away from residences.
23 Email from Arnicle Farm Resident (EM) to RES (MG) on 28 September 2022, at 15:43.
24 Email from RES (MG) to Arnicle Farm Resident (EM) on 29 September 2022 at 17:02.
25 Email from Arnicle Farm Resident (DM) to RES (MG) on 30 September 2022, at 09:27.
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73. If this “noise level” is supposed to refer to aerodynamic noise as well, then this statement is a profound scientific fallacy.
74. Not only do taller IWTs produce much more infrasonic energy, the taller the IWT, the further and stronger the infrasonic components will propagate.26
III. Wind Turbine Acoustic Signatures (WTAS)
75. Figure 1 is representative of the methodology imposed by legislation for the measurement of noise levels: temporal resolution of 10-minute averages, spectral resolution of 1/3rd of an octave, and sound pressure levels expressed in dBA.27
76. Scientists, however, are not constrained or restricted by these oversimplistic and antiquated methodologies.
77. Herein, acoustic environments are studied with a temporal resolution of 1 second and a spectral resolution of 1/36th of an octave.
78. For the layperson, one could say that IARO scientists are examining an acoustical environment with a microscope rather than a magnifying glass. That is, the resolution (temporal and spectral) is greatly increased.
79. Using new techniques to analyse recorded soundscapes,28 the significant differences detected in Environment A and Environment B (See Figure 1) become understandable.
80. Figure 4 shows the same frequency distribution in Environment A and Environment B, but with the above-mentioned increased spectral resolution: 1/36th of an octave instead of the 1/3rd of an octave as shown in Figure 1.
81. Figure 5 shows an educational representation of this same Figure 4.
26 Moller H, Pedersen CS. (2011) Low frequency noise from large wind turbines. Journal of the Acoustical Society of
America, 129(6):3727-44. doi: 10.1121/1.3543957.
27 It should be noted that these technical specifications are derived from the abilities of the best measuring instruments that existed almost a century ago.
28 Bakker HHC, Rapley BI, Summers SR, Alves-Pereira M, Dickinson PJ. (2017). An Affordable Recording Instrument for the Acoustical Characterisation of Human Environments. Paper presented at ICBEN-(International Commission for the Biological Effects of Noise)-2017, Zurich, Switzerland (Paper No. 3654). https://www.icben.org/2017/ICBEN%202017%20Papers/SubjectArea05_Bakker_P40_3654.pdf.
** The authors of this IARO Report hold no financial interest in the SAM technology.
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Figure 4. Frequency distribution of the same two environments shown in Figure 1, but with increased spectral resolution—1/36th of an octave instead of 1/3rd of an octave— and increased temporal resolution—1-second averages instead of 10-minute averages. Noticeably, Environment A presents with a series of peaks indicating a harmonic series (indicative of a train of pulses in the signal), while in Environment B this acoustic phenomenon is absent. It is pertinent to recall that both these environments have comparable “noise levels” as expressed in dBA (36 vs. 38 dBA) (See Figure 1).
82. It is pertinent to recall that the characterization of the two Environments, A and B, are the result of direct, scientific-grade field-measurements (not computer modelling) and
a. have similar noise levels as expressed in dBA (36 vs. 38 dBA),
b. have noise levels below the Target Value of 40 dBA, and,
c. are acoustically significantly different (74 vs. 58 dB-unweighted).
Figure 4 shows the presence of an acoustic phenomenon in Environment A which is absent in Environment B, namely, a train of pulses.
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Figure 5. Educational representation of Figure 3, pointing out portions of the graph that are relevant for understanding the matter at hand. This is the representation of the distribution of acoustic energy in an environment over frequency, based on the average of a 600-second (10- min) measurement. Infrasound (below 20 Hz) and low frequency noise (20–200 Hz) correspond to the frequency ranges as indicated. The noise level is expressed in dB on the Y axis. The red circle shows the spectral components of a train of pulses as a harmonic series with a fundamental frequency of 0.8 Hz, as indicated by the blue inverted triangles. They are generated by an IWT with a blade-pass frequency of 0.8 Hz.
83. For mathematical reasons, entirely explained in other scientific and peer-reviewed publications,29,30 these trains of pulses are representative of the acoustic output of IWTs, referred to as Wind Turbine Acoustic Signature (WTAS).
84. The existence of WTAS in Environment A is responsible for the significantly higher noise level in A (74 dB) when compared to Environment B (58 dB).
85. However, as can be seen in the comparative Figure 1, if the temporal and spectral resolution imposed by legislation is maintained—10-minute averages and 1/3rd octave
29 Bakker HHC, Alves-Pereira M, Mann R, Summers R, Dickinson P. (2023) Infrasound exposure: High resolution
measurements near wind power plants. In: Suhanek M, Kevin Summers J. (Eds) Management of Noise Pollution. IntechOpen: London. DOI: 10.5772/intechopen.109047,
30 Alves-Pereira M, Krough C, Bakker HHC, Summers R, Rapley B. (2019) Infrasound and low frequency noise guidelines – Antiquated and irrelevant for protecting populations. Proceedings of the 26th International Congress on Sound & Vibration, Montreal, Canada, July 7-11, No. 682. (Peer-Reviewed Conference Paper).
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band segmentation—then this type of information is not captured, and Environments A and B are (erroneously) considered comparable.
86. WTAS is deemed irrelevant to human health because it occurs, mainly, within the infrasonic range, which is considered to be inaudible to humans and, consequently, have no impact on human health.31
87. If WTASs are considered to be important enough to be quantified within the context of human health, the currently legislated noise-measurement methodologies would make this quantification impossible.
88. In a peer-reviewed scientific paper published in 2022, WTAS was specifically (strongly) correlated with sleep disturbance: When present the residents did not sleep, when absent they slept peacefully.32
31 Using ‘Light’ as an analogy, this is equivalent to believing that electromagnetic radiation that is not perceived through
the eyes (such as x-rays, microwaves, ultraviolet) are irrelevant to human health because they cannot be seen as light through the eyes. Moreover recent studies have shown that infrasonic signals can be processed by the brain but not conducted through the classical auditory pathways. See: Weichenberger M, Bauer M, Ku¨hler R, Hensel J, Forlim CG, Ihlenfeld A, et al. (2017) Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold: Evidence from fMRI. PLoS ONE, 12(4): e0174420. https://doi.org/10.1371/journal.pone.0174420.
32 Bakker HHC, Alves-Pereira M, Mann R, Summers R, Dickinson P. (2023) Infrasound exposure: High resolution measurements near wind power plants. In: Suhanek M, Kevin Summers J. (Eds) Management of Noise Pollution. IntechOpen: London. DOI: 10.5772/intechopen.109047,
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F. BRIEF REVIEW OF THE HEALTH EFFECTS CAUSED BY EXPOSURE TO INFRASOUND AND LOW
FREQUENCY NOISE
I. “What you can’t hear won’t hurt you”
The human hearing threshold begins at medium frequencies (500–4000 Hz) with a sound pressure level of 0–20 dB. For low-frequency ranges (0–200 Hz), the sound pressure must be significantly higher for the sound to be perceived—around 80 dB near 20 Hz and about 107 dB at 4 Hz. This principle must be considered when discussing the low-frequency noise impact of WPP’s. (Kobras Report, pp. 161)
89. There are several inaccuracies in the above paragraph, transcribed from the Kobras Report.
90. The most profound flaw is the assumption that health effects due to infrasound and low frequency noise exposures are only related to acoustic energy audible through the hearing function, i.e., “what you can’t hear won’t hurt you.”
91. This idea was shown to be a scientific fallacy as early as 1978, when it was proved that genetically deaf mice were greatly affected by infrasound exposures.33
92. More recently, it has been shown that the brain processes infrasound signals that are not relayed by the classical auditory pathways.34
93. The “principle [that] must be considered when discussing the low-frequency noise impact of WPP’s,” in the opinion of the authors of the Kobras Report is, in reality, a false issue.
94. Where WPPs are concerned, and contrary to the foundational precepts of Medical Sciences, great emphasis is placed on the question of perception or non-perception of
33 Busnel RG, Lehmann AG (1978). Infrasound and sound: Differentiation of their psychophysiological effects through
use of genetically deaf animals. Journal of the Acoustical Society of America, 63(3):974-977. https://pubmed.ncbi.nlm.nih.gov/670562/
34 Weichenberger M, Bauer M, Ku¨hler R, Hensel J, Forlim CG, Ihlenfeld A, et al. (2017) Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold: Evidence from fMRI. PLoS ONE, 12(4): e0174420. https://doi.org/10.1371/journal.pone.0174420.
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the “noise,” insinuating that, if the “noise” is not perceived through the auditory pathways, then it is not harmful.35
95. This notion is, of course, absurd (see Footnote 31).
96. Therefore, while the statement “For low-frequency ranges (0–200 Hz), the sound pressure must be significantly higher for the sound to be perceived—around 80 dB near 20 Hz and about 107 dB at 4 Hz” may be true, it has no relevance to health effects other than the hearing function.
II. Sources of Infrasound and Low Frequency Noise
Low-frequency components are present in most sounds, caused by both human-made sources (e.g., traffic) and natural sources (e.g., wind). For low- frequency sound to be disruptive or harmful to health, its sound pressure level is crucial. (Kobras Report, pp. 161)
97. Here, again, several inaccuracies are insinuated.
98. While it is true that “[l]ow-frequency components are present in most sounds, caused by both human-made sources (e.g., traffic) and natural sources (e.g., wind),” it is misleading to insinuate that these sources are similar or comparable. Indeed, they are significantly different. “[M]ost sounds” do not contain pulse trains, or even tonality, in this range.
99. The time profile over which acoustic events occur is of fundamental importance to determine health effects caused by this type of physical agent of disease (noise)—not merely the average level of sound pressure.
100. When statements such as “[f]or low-frequency sound to be disruptive or harmful to health, its sound pressure level is crucial” are provided, it misleads government officials and laypersons into believing that the sound level pressure is the most important factor (if not the only one) that matters when evaluating the health effects of ILFN exposures.
101. As shown in Figure 1, the generally used sound pressure level (expressed in dBA), does not differentiate between two significantly different acoustic environments.
Wind turbines, like many other sound sources, produce low-frequency sounds. However, current measurements and studies conducted at WPP’s
35 The word noise is here presented with quotes due to semantics: If the acoustical event is non-audible to humans,
and noise is defined as unwanted sound, then the noise that can be perceived but not heard must be presented as “noise.”
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have not detected low-frequency sounds at levels where they would be audible or cause health effects. (Kobras Report, pp.161)
102. Here, again, the scientific fallacies are shown to be deeply ingrained into SEA protocols:
103. “Current measurements… have not detected low-frequency sounds at levels where they would be audible...” Again, classical audibility of sound is deemed to be all-important, to the exclusion of all else. It is insinuated that action is necessary if, and only if, the low- frequency sound measurements are at levels considered audible. This perpetuates the notion “what you can’t hear won’t hurt you.”
104. “Current measurements… have not detected low-frequency sounds at levels where they would…. cause health effects.” This is not a scientifically proven, or provable, statement. The fact that some studies have found no health effects cannot be taken to prove that no health effects exist, especially when other studies disagree. See Annex B for an example of this situation.
Studies to date indicate that the low-frequency sounds caused by wind turbines are at a level comparable to ordinary environmental background noise (Leventhall, 2006). (Kobras Report, pp.161)
105. The average level of sound pressure may be comparable to ordinary background noise when using analyses with a spectral resolution of 1/3rd of an octave and a temporal resolution of 10-minute averages and, under these circumstances, could mask any differences in the character of the noise.
106. Yet, this is an antiquated methodology that is still in practice today (as imposed by legislative documents and guidelines), even though technology and analytical techniques have existed for many decades that permit a more scientific analysis of acoustic environments, with higher resolution.
107. Figure 6 shows the same two environments, A and B, as in Figure 1 and Figure 4, but here the data is presented in the form of Sonograms. Spectral resolution is 1/36th of an octave while the temporal resolution is 1-second, for a duration of 600 seconds (10 minutes).
108. Figure 7 is an educational representation of Figure 6.
109. Figure 6 shows, in each successive second, what SPL (in unweighted dB, given by the colour-scale) was present at each 1/36th octave band of the frequency spectrum.
110. The difference between the environmental background noise with and without the presence of a WTAS can be seen by any layperson.
111. The train of pulses of the WTAS, seen as the peaks of a harmonic series, in Figure 4 are manifested as the unbroken, horizontal lines seen in the corresponding sonogram
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(Environment A). That is, the peaks of energy seen in Figure 4 are present in each successive second, creating the horizontal lines.
112. These horizontal lines are absent in Environment B, as can be seen in the corresponding sonogram.
Figure 6. Sonograms of Environment A (top) and Environment B (bottom). The significant difference between these two acoustical environments is visually evidenced.
113. With these types of scientific-grade analyses, where the observation of the acoustic environment is accomplished with a higher temporal and spectral resolution of measurements —from magnifying glass to microscope-—natural background noise can be clearly differentiated from human-made noise. Nature does not generally produce acoustic events in straight lines (harmonic series) over such an extended period of time.
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Figure 7. Educational representation of Figure 6, pointing out portions of the graph that are relevant for understanding the matter at hand. This is the representation of the frequency distribution of an environment, based on the average of a 600-second (10-min) measurement. The regions corresponding to Infrasound (below 20 Hz) and low frequency noise (20-200 Hz) are indicated. Examples of SPLs as read with the colour-coded scale are given.
III. Studies cited by the Kobras Report
114. The Kobras Report refers to two studies in order to substantiate their position that noise emanating from WPPs has no impact on health (unless it is audible).
115. These studies are:
a. Maijala P, Turunen A, Kurki I, Vainio L, Pakarinen S, et al. (2020) Infrasound does not explain symptoms related to wind turbines. Publications of the Finnish Government’s Analysis, Assessment and Research Activities, 2020:34. Prime Minister’s Office: Helsinki.36 (Kobras Report, pp. 161), and
b. Marshall N, Cho G, Toelle BG, Tonin R, Bartlett DJ, et al. (2023) The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomised
36 https://julkaisut.valtioneuvosto.fi/handle/10024/162329
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Crossover Study in Noise-Sensitive, Health Adults. Environmental Health Perspectives, 131(3): 1-10.37 (Kobras Report, pp. 162)
116. IARO scientists have already performed a critical analysis of these (and other) studies. Regrettably, in the opinion of IARO scientists, these two studies have profound methodological flaws which fully invalidate the reported conclusions.
117. In Annex B, an excerpt of the 2024 IARO Arnicle Health Report is provided, where the critical analyses of these two studies are put forth, and the reasons why their conclusions are not based on the foundational principles of the Scientific Method are explained.
37 https://pubmed.ncbi.nlm.nih.gov/36946580/
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G. CONCLUSIONS
118. It is fully recognized by IARO scientists that Governments worldwide have been informed of the perceived economic benefits that WPPs might bring to their nations.
119. As demonstrated herein, these perceived economic benefits are accompanied by a substantial cost that is associated with the significant reduction in the health of human and animal population living in and around the vicinity of WPPs.
120. The Kobras Report submitted to the local government officials in Estonia, because of its good compliance with SEA Directives, perpetuates flawed and archaic methodologies regarding noise assessments for the prevention of harmful effects to health.
121. These flawed and archaic methodologies are used to justify conclusions that are, oftentimes, outright scientific fallacies.
122. This is particularly true for the health impacts induced by the acoustic output of WPPs.
123. Because Subsection 4.6.1 of the Kobras Report appears to be in good compliance with Estonian governmental legislation and EU SEA Directives, it continues to propagate the scientific fallacy that “what you can’t hear, can’t hurt you.”
124. It is hoped that the relevant authorities and the general public will take the following Recommendations under consideration.
a.
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H. RECOMMENDATIONS
125. The Kobras Report states that a second phase for this project, proposing the installation of multiple WPPs throughout the Estonian countryside, might be undertaken.
126. If a second planning phase is undertaken, the following recommendations are suggested for decision-makers, governmental officials and the general public (as applicable):
I. Acoustics
127. Baseline noise recordings should be conducted prior to any initial construction of any WPP and must include the infrasonic region of the acoustic spectrum.
128. Analysis of these recordings must include low-resolution averages expressed in dB unweighted and must include high-resolution samples over the infrasonic and low- frequency regions.
129. This means that noise measurement protocols cannot be exclusively dictated by current legislation, but rather, by proper scientific practices.
130. These noise measurements cannot be substituted by computer modelling techniques.
131. After the installation of WPPs, these noise recordings and analyses should be regularly performed for a minimum of five years (assuming that all approved WPPs will be fully installed and operational within the next five years).
132. As the propagation of WTAS is directional, the recordings and analyses should include the full range of wind directions and weather conditions present over all seasons.
133. These actions should be taken under the auspices of the Estonian governmental agency responsible for Public Health. In their absence, these actions should be taken by individual citizens under Citizens’ Science Initiatives.
II. Public Health
134. Prior to the installation of any WPP, neighbouring residents (up to 20 km away from the proposed WPPs) should be interviewed to ascertain their a) extent of prior ILFN exposures, b) current clinical situation, and c) past medical histories.
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135. During and after the installation of WPPs, residents should be monitored as to pertinent and relevant clinical and reproductive outcomes (and not merely for subjective, psychoacoustic parameters) for a minimum of five years.
136. These actions should be taken under the auspices of the Estonian governmental agency responsible for Public Health. In their absence, these actions should be taken by individual citizens under Citizens’ Science Initiatives.
III. Livestock Health
137. Detailed reports should be prepared by livestock owners regarding mortality, birth rates and sickness among their animals before the installation of any WPP.
138. Monitoring of these parameters must be maintained for a minimum of 5 years after the installation of the WPPs.
139. These actions should be taken under the auspices of the Estonian governmental agency responsible for Animal & Livestock Health. In their absence, these actions should be taken by individual citizens, under Citizens’ Science Initiatives.
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Report on Phase 1 of Strategic Environmental Assessment for Dedicated Spatial Plan of Wind Power Plants, including Pre-selected Locations in Põhja-Pärnumaa Parish Prepared by Kobras OÜ in November 2024
Ordered by Local Government of Põhja-Pärnumaa Parish
Translated by NPO For Nature and People (MTÜ Looduse ja Inimeste Eest) with the assistance of AI translator (ChatGPT)
4.6 IMPACT ON HUMAN HEALTH AND WELL-BEING
4.6.1 Noise
Noise is an unpleasant, disturbing, or otherwise health- and well-being-damaging sound. It is one of the most common and significant factors that degrade the quality of the living environment. Noise affects health and well-being in various ways—it can interfere with or make working, communication, and resting difficult, cause permanent ear damage leading to hearing impairment, induce stress, or trigger various functional disorders. The transmission of noise to the affected object depends on wind speed and direction, air humidity, and thermal stratification. The propagation of sound waves in the near-ground atmospheric layer is significantly influenced by the terrain characteristics, particularly the nature of the surface— topography, vegetation, water bodies, and buildings.
4.6.1.1 Construction Noise
Noise associated with the construction of WPP’s is similar to that of typical construction activities. Considering that all potentially suitable areas are located at least 1 km away from the nearest residence, it is unlikely that significant construction-related noise disturbances will occur for people.
4.6.1.2 Operational Noise The noise sources in WPP’s can be divided into two categories:
• Mechanical noise generated by the gearbox, motor, and other mechanisms of the wind turbine.
• Aerodynamic noise created by the rotor blades moving through the air.
Modern wind turbines have been designed with considerable attention to noise reduction. Mechanical noise has been significantly minimized through the use of various insulation materials and technical solutions. Similarly, technical measures have been implemented to reduce aerodynamic noise. However, since these are large technical devices, some level of noise emission is inherent during the operation of wind turbines.
The assessment of operational noise from wind turbines was conducted based on the Atmospheric Air Protection Act and the Minister of the Environment Regulation No. 71 of 16 December 2016 on "Limit values for noise transmitted in ambient air and methods for measuring, determining, and assessing noise levels."
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Wind turbine noise is classified as industrial noise.
According to the Atmospheric Air Protection Act, the limit values for noise transmitted in ambient air are as follows:
1. Noise limit value – the maximum permissible noise level, exceeding which causes significant environmental disturbance and necessitates the implementation of noise reduction measures.
2. Target Noise Level – the maximum permitted noise level for areas designated under new general plans.
For residential areas, the noise limit value for industrial noise is 60 dBA during the day and 45 dBA at night. The target value is 50 dBA during the day and 40 dBA at night.
A newly planned area, as defined in Regulation No. 71, is a previously undeveloped noise-sensitive area located outside densely populated or compactly built-up areas. The Ministry of the Environment has provided guidance (Ministry of the Environment, 2021b) and positions (letter No. 7-15/21/3300- 2 dated 13.09.2021) recommending that WPP planning adhere to noise limit values. However, the Supreme Court has determined that WPP projects should comply with target values (referred to as "design values" in applicable legislation) (Supreme Court ruling No. 3-3-1-88-15, 2016).
Since wind turbines operate continuously, and their noise can be considered more disturbing than some other types of industrial noise, it is recommended that WPP plans and projects aim to achieve the nighttime target value of 40 dB in residential areas. This means that the total noise emitted by the entire WPP, not just an individual turbine, must not exceed 40 dB.
It is important to note that noise limit values apply to the average noise level during the day (7:00– 23:00) and night (23:00–7:00). However, noise assessments for WPP’s are based on worst-case scenarios, assuming turbines operate continuously.
It should also be noted that there is a distinction between noise levels exceeding regulatory limits and noise levels causing annoyance. Noise standards are designed to ensure noise levels do not harm human health. This does not mean that the noise source will be inaudible. In the case of annoyance, the noise source is audible and may be unpleasant, but it does not constitute a health-threatening situation. The perceived annoyance of noise depends significantly on individual perception. Various studies have proposed 35 dB as the annoyance threshold for WPP noise (Schmidt et al., 2014). However, as mentioned, individual sensitivity to wind turbine noise varies.
The noise generated by turbines depends on wind strength. With weaker winds, the rotational speed of the turbine is lower, resulting in a lower noise level. As wind speed increases, the rotational speed rises, but natural ambient noise also increases, partially masking the turbine noise.
For new plans, wind turbine noise is assessed through computational modeling. In this case, the specialized software WindPRO 3.6 was used. The calculations were based on the international standard ISO 9613-2: "Acoustics – Attenuation of sound propagation outdoors, Part 2: General method of calculation," which is the recommended industrial noise calculation method for European Union member states without national calculation methods (European Parliament and Council Directive 2002/49/EC, 25 June 2002, concerning the assessment and management of environmental noise). This standard is widely used for evaluating noise propagation from WPP’s globally.
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Estonia has not established detailed requirements for input parameters in wind turbine noise modeling. In this case, noise propagation was modeled under unfavorable conditions – with a tailwind maximally favorable for noise transmission in all directions. According to technical data from turbine manufacturers, turbine noise emission typically increases up to wind speeds of 7–8 m/s. Additionally, at wind speeds above 8 m/s, natural wind noise begins to mask turbine noise.
The WindPRO calculation software allows for noise propagation assessments at various wind speeds; in this study, the worst-case conditions were considered.
The worst-case wind speed was used, meaning that noise maps were presented for conditions where noise levels were at their maximum (the program's automatic "Highest noise value" setting was applied). Noise modeling was conducted at a height of 2 m above the ground (the standard "ear" height used in Estonia for creating national noise maps). The calculation grid resolution was set at 10 m.
The meteorological coefficient was set to 1, and the ground roughness factor was set to 0.5 for the entire area. The terrain data were imported into the model based on elevation data from the Estonian Land Board (5 m resolution digital elevation model). Atmospheric conditions were modeled using WindPro's default settings (temperature 10°C and 70% humidity).
Objects that could directly block noise propagation, such as trees and forest areas, were not considered in the modeling. Similarly, existing buildings were not designated in the program as noise-blocking objects. In reality, if forest patches or auxiliary buildings lie between turbines and receptors, the actual noise levels experienced will be lower than those shown in the calculations. Therefore, the daily noise levels caused by the turbines are expected to be lower than the modeling results.
Considering research findings that wind turbine noise is inherently more disturbing than, for example, traffic noise, and the fact that ISO 9613-2 is not explicitly designed for noise assessments over long distances, a conservative approach to WPP noise assessments is justified.
Noise maps were created to depict A-weighted equivalent sound pressure levels LpA,eq in decibels, presented in 5 dB noise intervals. Noise levels at specific residential areas within the affected zone were not calculated (no receptor points were assigned). A more detailed noise assessment for each residential area within the impact zone is appropriate for the next phase of the special plan (e.g., detailed design or construction project preparation), once specific turbine locations are known.
In collaboration with stakeholders, the maximum potential number of turbines and their locations in potentially suitable areas were forecasted (illustrations in Schemes 72–74) to conduct noise modeling. The maximum number of turbines for each area is provided in Table 12. The turbine locations at this pre-selection stage are illustrative and will be refined in the next phase of the special planning process (detailed design or construction project preparation).
The noise map was created for a scenario in which all suitable areas under the Põhja-Pärnumaa Parish special plan were developed, accounting for potential cumulative impacts.
As input for noise modeling, a theoretical wind turbine with an emitted noise level of 108 dB was used for potentially suitable areas under the special plan. According to the WindPro database, modern turbines generally do not emit such high noise levels; most turbine models have emitted noise levels between 105–107 dB. As an exception, for the area marked as No. 11 in Schemes 72 and 73, an
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emitted noise level of 106 dB was considered. The theoretical rotor diameter was assumed to be 180 m, and the tower height was 200 m.
The noise level is not directly dependent on the size of the turbine. Rather, for turbines with the same noise emission, the noise level reaching residential areas is somewhat lower for taller turbines, as the distance is greater.
Table 12. Allowed maximum amount of IWT’s on special planning suitable areas
Scheme 72. Number of wind turbines and their potential locations in the areas deemed suitable under the special plan.
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Scheme 73. Number of wind turbines and their potential locations in the areas deemed suitable under the special plan.
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Scheme 74. Number of wind turbines and their potential locations in the areas deemed suitable under the special plan. Additionally, a noise map was created for a scenario where, in addition to the areas planned under Põhja-Pärnumaa Parish special plan, the areas designated by the Tootsi Suursoo WPP thematic plan and the Tori Northern Area special plan, as well as the development areas P7, P9, P10, P11, and P25 from the Pärnu County Wind Energy Thematic Plan, are fully realized (see Scheme 75 and Table 13). For the Tori Northern Area special plan, theoretical turbines with a rotor diameter of 180 meters and a tower height of 200 meters were used in noise modeling. According to the Pärnu County Wind Energy Thematic Plan, the rotor diameter of turbines in development areas P7, P9, P10, P11, and P25 was set at 180 meters, with a tower height of 160 meters. For both plans, the noise emission of turbines was considered to be 108 dB(A). As an exception, for area P9, a noise level of 106.9 dB(A) was used, based on the detailed plans for the P9 and P10 WPP’s.
Regarding the Tootsi Suursoo WPP, it is known that Nordex turbines are planned to be used, with a rotor diameter of 163 meters and a height of 164 meters. The noise emission level of a Nordex turbine is 106.4 dB(A). The results of the noise modeling are presented in Appendix 3.
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Table 13. Basis for noise modelling based on the amount of IWT’s from other plannings Planeering – planning Tuulikute arv – Amount of IWT’s
Scheme 75. Locations of areas potentially suitable under the special plan, alongside other planned WPP areas within and near Põhja-Pärnumaa Parish. Results Noise modeling revealed that if all areas are developed to the maximum extent indicated in Table 12, the nighttime noise target value (40 dB) may potentially be exceeded (or reached) in residential areas surrounding potential suitable area no. 3 (see Scheme 76). For the other potential suitable areas (5, 7, 8, 9, 10, 11, and 12), no exceedance of the nighttime noise target value in residential areas was observed.
In this case, residential areas where the noise limit value is applied instead of the target value due to agreements with landowners were not considered in the analysis. For all areas, the nighttime noise limit value (45 dB) is ensured in residential areas.
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In the development of potential suitable area no. 3, the nighttime noise target value is exceeded (or reached) in 3 residential areas. Residential areas are defined as land designated for residential purposes and the yard areas of residences located on agricultural land.
In a scenario where all potential suitable areas within the Põhja-Pärnumaa Parish special plan are developed, cumulative noise effects occur between areas 10 and 12. The remaining areas are located sufficiently far apart to avoid cumulative noise impacts. Despite the cumulative effect between areas, the nighttime noise target value is not exceeded in residential areas.
Scheme 76. Noise propagation modeling results for Potentially Suitable Area 3 under the maximum development scenario of the WPP.
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Scheme 77. Noise propagation modeling results for Potentially Suitable Areas 5 and 11 under the maximum development scenario of the WPP.
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Scheme 78. Noise propagation modeling results for Potentially Suitable Area 7 under the maximum development scenario of the WPP.
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Scheme 79. Noise propagation modeling results for Potentially Suitable Area 8 under the maximum development scenario of the WPP.
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Scheme 80. Noise propagation modeling results for Potentially Suitable Area 9 under the maximum development scenario of the WPP.
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Scheme 81. Noise propagation modeling results for Potentially Suitable Areas 10 and 12 under the maximum development scenario of the WPP. A noise map was created for the scenario where, in addition to the areas planned under the Põhja- Pärnumaa Parish’s special plan, all other WPP areas planned within Põhja-Pärnumaa Parish and its vicinity are realized (Schemes 82–84). The map indicates two main regions where the cumulative impact of different plans worsens the noise situation: Tellissaare Bog and Pitsalu Village Area. In the Pitsalu Village area, cumulative impacts arise between potential suitable area 12 and development area P7 of the Pärnu County wind energy thematic plan, affecting approximately three residential areas (plots Anni (18801:003:0075), Annuse (18801:003:0136), and Liiva (18801:003:0021)).
In the Tellissaare Bog area, cumulative noise impacts occur between potential suitable areas 7 and 8 and development areas P9 and P10 of the Pärnu County wind energy thematic plan. When potential suitable area 7 and development area P10 are developed, the nighttime noise target value in Põhja- Pärnumaa Parish is exceeded for approximately five residential areas. Additionally, the combined impact of potential suitable area 8 and development area P9 results in the target value being exceeded for approximately two residential areas.
In such a case, the Kruse cadastral unit (93005:002:0103) may also experience an exceedance of the nighttime noise limit value applicable to residential land. Noise modeling results show that the 45 dB limit is barely met on the Kruse residential land area.
Exceeding the noise limit poses a risk to human health and constitutes a significant negative impact.
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Scheme 81. Noise propagation modeling results for Potentially Suitable Areas 10 and 12 under the maximum development scenario of the WPP.
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Scheme 82. Results of the cumulative noise modeling between the Potentially Suitable Areas of the Põhja-Pärnumaa Special Plan and WPP areas from other plans.
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Scheme 83. Results of the cumulative noise modeling between the Potentially Suitable Areas of the Põhja-Pärnumaa Special Plan and WPP areas from other plans.
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Scheme 84. Results of the cumulative noise modeling between the Potentially Suitable Areas of the Põhja-Pärnumaa Special Plan and WPP areas from other plans. When considering the noise modeling results, it is important to recognize that the modeling did not account for noise-dampening objects, including vegetation. Several potential areas in the special plan are located in forested regions, which means that, in reality, the noise levels caused by wind turbines in residential areas are lower than what is reflected on the noise maps. Additionally, the noise from wind turbines has been overestimated in the modeling process. The noise level near the closest noise-sensitive buildings largely depends on the placement of the turbines. For potential area 3, the residential areas where the nighttime target value is exceeded are marginally affected. Therefore, during the next phase of the special plan (preparation of a detailed solution or construction project), adjustments to the turbine locations can ensure compliance with the target value for these residential areas.
Since the turbine layout at the site pre-selection stage is indicative, a new noise level model must be conducted during the detailed solution or construction project phase of the special plan. This new modeling must be based on the actual planned turbine locations and the best available knowledge at the time regarding the calculation of wind turbine noise.
It must be ensured that only new (not used) turbines are utilized in the WPP’s. Additionally, the noise emissions of the turbines placed in the area must not exceed 108 dB, and for area 11, this limit is 106 dB. The turbine placement in the detailed solution or construction project of the special plan must be optimized to ensure that the nighttime target value for industrial noise is met on residential land, in accordance with the Minister of the Environment's regulation No. 71 of December 16, 2016.
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Exceptions include the Kruse cadastral unit (identifier: 93005:002:0103) in Vihtra village, Koiva (93002:004:0135) in Kadjaste village, and Uue-Auru (93002:004:0034) in Oriküla (Geoportal of the Land Board, December 16, 2022). For these cadastral units, the nighttime limit value for industrial noise must be ensured. The owners of the Koiva and Uue-Auru cadastral units are given their consent to Enefit Green, which is interested in developing area 11, to install wind turbines at distances of 800 meters and 600 meters from residential buildings located on the cadastral units (800 meters for the Koiva cadastral unit and 600 meters for the Uue-Auri cadastral unit).
6.1.3 Low-Frequency Noise
The human hearing threshold begins at medium frequencies (500–4000 Hz) with a sound pressure level of 0–20 dB. For low-frequency ranges (0–200 Hz), the sound pressure must be significantly higher for the sound to be perceived—around 80 dB near 20 Hz and about 107 dB at 4 Hz. This principle must be considered when discussing the low-frequency noise impact of WPP’s. Low- frequency components are present in most sounds, caused by both human-made sources (e.g., traffic) and natural sources (e.g., wind). For low-frequency sound to be disruptive or harmful to health, its sound pressure level is crucial.
Wind turbines, like many other sound sources, produce low-frequency sounds. However, current measurements and studies conducted at WPP’s have not detected low-frequency sounds at levels where they would be audible or cause health effects. Studies to date indicate that the low-frequency sounds caused by wind turbines are at a level comparable to ordinary environmental background noise (Leventhall, 2006).
Low-frequency noise has consistently been a significant topic concerning wind turbines, as noise propagation can cover a large area. During propagation, the normal and higher frequency components of sound attenuate faster in air than low-frequency components (Hansen et al., 2017).
One of the most comprehensive studies on low-frequency noise related to wind turbines was conducted in Finland and published in English in 2020 (Maijala et al., 2020). The study, commissioned by the Finnish government, was carried out by the VTT Technical Research Centre of Finland. It combined long-term measurements (308 days) of sound levels at WPPs, as well as hearing tests and surveys among residents living near WPPs. The aim was to determine the characteristics of low-frequency noise produced by turbines and its potential effects on humans.
The study was prompted by complaints from some residents near WPPs, who attributed health issues—particularly sleep disturbances—to the presence of turbines. According to the study, 5% of residents near WPPs included in the survey (so-called “symptomatic respondents”) associated their health problems with low-frequency noise from turbines. Most symptomatic respondents lived within 2.5 km of the WPP, which was defined as the near area in the study. Among these residents, 15% identified as symptomatic.
Measured low-frequency noise in WPP areas generally ranged between 0.1–1 Hz, which is below the human hearing threshold (16–20 Hz). The lower the sound frequency, the higher the sound pressure must be for the sound to be audible.
The study identified a new aspect: wind turbines can produce occasional low-frequency noise peaks (short bursts of sound pressure up to 102 dB). These peaks might theoretically be audible to some
Translation in English of section 4.6.1 of the Kobras OÜ’s report
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individuals. However, it could not be demonstrated that individuals who reported health effects attributed to wind turbines were better able to perceive low-frequency noise. Hearing tests attempted to detect nervous system responses to low-frequency noise among individuals reporting health problems, but no such connection was found.
No reactions in the nervous system or other physiological parameters of these individuals were observed when they were exposed to low-frequency noise from turbines.
The study also found that within a 1.5 km radius of a WPP, changes in the sound spectrum could be noted, resulting in a more “urban” profile—increasing the proportion of low-frequency noise in the frequency distribution. The resulting sound spectrum becomes very similar to that in urban environments.
The study concluded that low-frequency noise from wind turbines cannot be linked to the health effects reported by individuals. However, a hypothesis was raised that the fluctuation in the amplitude of the turbine sound could potentially be more significant than low-frequency noise itself. One of the most recent studies on turbine infrasound was published in 2023, which investigated the long-term impact of infrasound on human health. The Woolcock Institute of Medical Research in Australia studied how infrasound from wind turbines affected 37 healthy adults over a 72-hour period. During the experiment, participants were placed in a sleep laboratory where unique sounds were played to them, including infrasound levels that mimic the infrasound produced by wind turbines. A control group was also included in the study, which was not exposed to infrasound but was exposed to traffic noise. At the end of the three-day experiment, it was concluded that infrasound had no effect on various health indicators of the participants (e.g., sleep, blood pressure, balance, hearing, etc.) (Marshall et al., 2023).
The noise levels for low-frequency noise are set by the Minister of Social Affairs in Regulation No. 42 of 04.03.2002 "Noise Norms for Living and Recreation Areas, Residential Buildings, and Shared Buildings, and Methods for Measuring Noise Levels" (Annex, Table 14). The noise levels in the annex refer to the sound pressure levels for assessing the disturbance caused by low-frequency noise in living and sleeping areas of residential buildings, and equivalent spaces during the night. These are not outdoor norms, but rather those that apply inside buildings.
Tabel 14. Low frequency noise values inside living quarters.
1/3 oktaaviriba kesksagedus Hz – 1/3 of octave band center frequency.
Helirõhutase - SPL
In Estonia, there are no national guidelines on how to calculate the propagation of low-frequency noise from wind turbines and its compliance with the values applicable in indoor spaces. However, in Finland, such an assessment guideline exists (Ympäristöhallinnon Ohjeita 2, 2014). Based on
Translation in English of section 4.6.1 of the Kobras OÜ’s report
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low-frequency noise modeling for other WPPs using this guideline, it has been found that at a distance of 1 km from the wind turbines, residential areas are not expected to exceed the recommended low-frequency noise value in living spaces (LEMMA OÜ, 2022). In this case, the potentially suitable areas are located at least 1 km away from residential buildings, so it can be assumed that the low-frequency noise values in living spaces are ensured.
Annex 3
Special planning noise map of Põhja-Pärnumaa Parish.
Translation in English of section 4.6.1 of the Kobras OÜ’s report
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"Noise map for a theoretical scenario where the areas of Põhja-Pärnumaa Parish’s special plan (EP), Tootsi Suursoo WPP (TP), and the northern part of Tori's special plan (EP), as well as the development areas P7, P9, P10, P11, and P2 of the Pärnu County plan (MP), have been realized."
Põhja-Pärnumaal, 19. jaanuaril 2025
MTÜ Looduse ja Inimeste Eest
täiendav arvamus ja ettepanekud
„PÕHJA-PÄRNUMAA VALLA TUULEPARKIDE ERIPLANEERINGU ASUKOHA EELVALIK JA
KESKKONNAMÕJU STRATEEGILISE HINDAMISE I ETAPI ARUANNE (redaktsioon: november 2024)“
kohta
MTÜ Looduse ja Inimeste Eest („MTÜ“) leiab, et Põhja-Pärnumaa valla tuuleparkide eriplaneeringu
keskkonnamõju strateegilise hindamise I etapi aruandes („KSH aruanne“) viidatud uuringud ja
modelleeringud, mis käsitlevad müra, sh infraheli, on ebaadekvaatsed.
MTÜ on tellinud teadusliku eksperthinnangu (lisatud käesolevale täiendavale arvamusele), mis seab
kahtluse alla KSH aruandes refereeritud teadusuuringute – näiteks, Maijala (2020) ja Marshalli (2023)
uuringud – sobivuse tuuleelektrigeneraatorist („tuugen“) lähtuva müra tervisemõjude hindamiseks.
Samuti seab IARO eksperthinnang kahtluse alla müra, sh inframüra mõõtmise metoodika sobivuse
tuugenist lähtuva müra adekvaatseks mõõtmiseks.
Sellest tulenevalt leiab MTÜ, et KSH aruandes aluseks võetud teadusuuringud ei ole piisavad
tuvastamaks, et infraheli on ohutu inimestele ja loomadele.
MTÜ Looduse ja Inimeste Eest teeb ettepaneku peatada Põhja-Pärnumaa valla tuuleparkide
eriplaneering, kuni on veenvalt ja teaduspõhiselt tuvastatud, et tuuleparkidest tulenev infraheli on
inimesele ja loodusele täiesti ohutu, seda ka pikaajalise kokkupuute ehk tuulepargi mõjualas
elamise korral, ning järgida IARO soovitusi (IARO eksperthinnangu punktid 125–139).
Märkus:
MTÜ Looduse ja Inimeste Eest tellitud IARO eksperthinnang koos selle lisadega A ja B on MTÜ
Looduse ja Inimeste Eest intellektuaalomand. Seda tohib levitada ainult koos viitega
mittetulundusühingule Looduse ja Inimeste Eest.
Lugupidamisega,
Urmas Maranik
MTÜ Looduse ja Inimeste Eest
/allkirjastatud digitaalselt/