Insistent wind critic Robert Bryce had a column in the National Review last week which raised a number of objections to wind power. Clean Line Energy’s Jimmy Glotfelty responded in an op-ed, to which Mr. Bryce has written an additional response. Among the issues Mr. Bryce discusses is that of wind turbine sound. The following comment on his assertions is from Christopher Long, AWEA’s Manager of Offshore Wind and Siting Policy.
With regards to the issue of wind turbines and human health, the credible peer-reviewed scientific data and various government reports in the U.S., Canada, Australia and the U.K. refute the claim that wind farms cause negative health impacts. For example, in their own independent reviews of available evidence, Ontario’s Chief Medical Officer of Health and Australia’s National Health and Medical Research Council found that sound from wind turbines does not cause negative health impacts. See http://news.ontario.ca/mohltc/en/2010/05/new-report-from-ontarios-chief-medical-officer-of-health-says-there-is-no-direct-causal-link-between.html (Ontario) and http://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/new0048_evidence_review_wind_turbines_and_health.pdf (Australia).
Furthermore, as part of the wind industry’s commitment to examining this issue, the American and Canadian Wind Energy Associations (AWEA and CanWEA) established a scientific advisory panel in early 2009 to conduct a review of current literature available on the issue of perceived health effects of wind turbines. This panel reached the same conclusion that the sound from wind turbines does not cause negative health impacts. To read the panel’s report, please visit http://www.awea.org/learnabout/publications/upload/AWEA_and_CanWEA_Sound_White_Paper.pdf.
Many of the quotes utilized by Mr. Bryce are taken out of context. For example, regarding the 2001 National Institutes of Health (NIH) report, he selectively quotes the results of a simulation which was conducted at higher sound levels than those associated with wind turbines and he fails to acknowledge that real world experience found no correlation with such symptoms. Furthermore, there was no mention of wind turbines in the 2001 study, though it does note that everyday activities such as driving in an automobile with the windows closed are a common source of infrasound exposure in the range of 90 to 110 dB, which is higher than the level that may be experienced near a wind farm.
In addition, regarding the issue of infrasound, an independent peer-reviewed study conducted on behalf of the Swedish Environmental Protection Agency and the Swedish Research Council found that: “Infrasound (1–20 Hz) from wind turbines is not audible at close range and even less so at distances where residents are living. There is no evidence that infrasound at these levels contributes to perceived annoyance or other health effects.” (Bolin, et al 2011: http://iopscience.iop.org/
Regarding the statement by Jim Cummings on the Massachusetts Department of Environmental Protection study, it has been well established that one’s reaction to environmental sound, be it a new roadway, airport expansion, mining activities or a new power plant, is subject to “many confounding factors that can affect the reactions and there is currently no clear relationship between a noise descriptor and a particular physiological effect.” (Burgess & Finegold in Crocker: Handbook of noise and vibration control ISBN 978047139599-7).
Furthermore, a recent sociological evaluation of rural wind farm development in Australia [Hall 2012] also found that community responses to wind facilities vary for a variety of non-acoustical reasons:
“Community members publicly opposing their local wind farm spoke as self-appointed representatives for others nursing grievances with wind farms. Most were hobby farmers with small acreages, former professionals and/or members of Landscape Guardian groups [groups concerned with visual impacts].” (p. 59)
And (p 52): “This opposition has several origins including a symbolic response of rural communities to political neglect from cities, an anti-development stance, and also opposition to a green or climate action political agenda … ”
[Hall, N., Ashworth, P., Shaw, H. “Exploring community acceptance of rural wind farms in Australia: a snapshot”, CSIRO Science into Society Group. January 2012]
Regarding the issue of sleep disturbance, the extensive literature on sleep disturbance from other sources of environmental sound over multiple decades does not provide precise guidance, which raises a serious question about the value of additional research and how similar inconclusive results may be valued.
Regarding references to research conducted by Alec Salt, Mr Bryce fails to acknowledge Massachusetts’s review of Salt’s hypothesis and also fails to express that the percentage of individuals reporting these symptoms is small. In their study, the authors of the Massachusetts study write “So at this moment, inner ear experts have not found a method for airborne infrasound to impact the inner ear. The potential exists such that the outer hair cells (OHC) respond to infrasound, but that the functional role of the connection between the OHC and the brain remains unknown. Further, the modulation of the sound received at the inner hair cells (IHC) itself has not been shown to cause nausea, headaches, or dizziness.”
Regarding the article published in Acoustics Today by undergraduate student Annie Chen and her advisor, Peter Narins, the undergraduate researcher apparently did not check her sources very thoroughly, as several had been critically critiqued. Sound expert Carl Bolin wrote in a paper sponsored by the Swedish EPA, “Two articles (Jung and Cheung 2008 and Sugimoto et al 2008) have been cited as arguments that wind turbines generate high levels of infrasound and LFN (Salt and Hullar 2010). However, the measurements reported in those articles were made in close proximity to wind turbines and are uncharacteristic of exposure in residential buildings. Jung and Cheung (2008) measured at 10 and 98 m from a 1.5-MW turbine with levels exceeding 80 dB in the frequency range 1–10 Hz. Sugimoto et al (2008) report levels of up to 80 dB in the frequency range 1–20 Hz inside a small shed 20 m from the wind turbine.” As noted above, the NIH study found that such levels of infrasound are experienced in passenger vehicles.
And furthermore, Ms. Chen’s reference to Moller & Pederson (2011) fails to acknowledge their statements that “… [T]urbines do emit infrasound (sound below 20 Hz), but levels are low when human sensitivity to these frequencies is accounted for. Even close to the turbines, the infrasonic sound pressure level is much below the normal hearing threshold, and infrasound is thus not considered as a problem with turbines of the investigated size and construction.”
Ms. Chen also states that, “In another study, Pedersen et al. interviewed 70,000 adults living within 2.5 km of wind farms”. Had the references been thoroughly reviewed and understood, she would have learned that this was a mail-in survey questionnaire with 700 participants rather than interviews of 70,000 adults. And the researchers involved in these efforts have not identified infrasound as a concern for modern wind turbines.
Despite the solid scientific studies from numerous credible sources, scare tactics live on. But, the fact remains that the combined benefits of wind energy–no pollution or water usage associated with energy production, zero carbon emissions–all serve to make wind power far more friendly to human health than other more traditional forms of energy production.”