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Resource Documents: Noise (518 items)

RSSNoise

Also see NWW press release on noise

Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are provided to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate.


Date added:  November 26, 2014
Aesthetics, Environment, Noise, WildlifePrint storyE-mail story

Environmental issues associated with wind energy — a review

Author:  Dai, Kaoshan; Bergot, Anthony; Liang, Chao; Xoang, Wei-Ning; and Huang, Zhenhua

Recognized as one of the most mature renewable energy technologies, wind energy has been developing rapidly in recent years. Many countries have shown interest in utilizing wind power, but they are concerned about the environmental impacts of the wind farms. The continuous growth of the wind energy industry in many parts of the world, especially in some developing countries and ecologically vulnerable regions, necessitates a comprehensive understanding of wind farm induced environmental impacts. The environmental issues caused by wind farms were reviewed in this paper by summarizing existing studies. Available mitigation measures to minimize these adverse environmental impacts were discussed in this document. The intention of this paper is to provide state-of-the-art knowledge about environmental issues associated with wind energy development as well as strategies to mitigate environmental impacts to wind energy planners and developers.

Renewable Energy 75 (2015) 911–921

Sections:
Wind energy induced environmental issues:
Effects on birds
Effects on bats
Effects on marine species
Deforestation and soil erosion
Noise
Visual impact
Reception of radio waves and weather radar
Climate change

Mitigation of wind energy environmental risks:
Limiting the effects on birds and bats
Reducing influence on marine environment and climate
Noise reduction
Mitigating visual impact
Reducing electromagnetic interference

Download original document: “Environmental issues associated with wind energy — a review”

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Date added:  November 19, 2014
Health, NoisePrint storyE-mail story

Negative health impact of noise from industrial wind turbines: How the ear and brain process infrasound

Author:  Punch, Jerry; and James, Richard

This article, the final of three installments, discusses the relationship between various health effects and our current understanding of the processing of infrasound by the ear and brain. [Part 1: Some Background; Part 2: The Evidence.]

As noted in the second installment of this series, Dr. Geoff Leventhall, a co-author of the 2009 AWEA/CanWEA report, attributes the health complaints of people who live near industrial wind turbines (IWTs) to psychological stress, but does not acknowledge that IWTs can be detrimental to health because infrasound and low-frequency noise (ILFN) emitted by wind turbines are largely inaudible to humans. He stands on the argument, therefore, that what we can’t hear can’t hurt us.

We know that things we cannot see, touch, taste, or smell can hurt us, so why is it unreasonable also to believe that what we can’t hear might also hurt us?

Dr. Nina Pierpont, in describing Wind Turbine Syndrome (WTS), has expressed her belief that many of the symptoms comprising WTS are mediated by overstimulation of the vestibular system of the inner ear by ILFN. Recent evidence supports the general view that the functioning of both the vestibular and cochlear components of the inner ear, and their interconnections with the brain, mediate the type of symptoms that Pierpont and others have described.

INFRASOUND: MORE OF A PROBLEM THAN WE THOUGHT?

Industrial-scale wind turbines generate peak sound pressure levels at infrasonic frequencies, especially between 0.25 and 3 Hz, as the blades pass in front of the tower. Most of us do not experience the energy in this lowest of low-frequency regions as sound; instead, we perceive a variety of other sensations. When present, infrasound can be more of a problem than audible sound.

Recent basic research on the inner ear conducted by Dr. Alec Salt and colleagues at the Washington University School of Medicine in St. Louis has provided a feasible and coherent explanation of how sound that is normally not audible can result in the kinds of negative reactions reported by people who are exposed to wind turbine noise. That research has shown that extremely low-frequency sound is largely inaudible to humans because the outer hair cells (OHCs) in the inner ear detect and effectively cancel it before it reaches the inner hair cells (IHCs). The IHC stereocilia, which do not contact the tectorial membrane, are fluid-coupled and sensitive to stimulus velocity, while the OHC stereocilia are sensitive to displacement. IHCs rapidly become less sensitive as stimulus frequency is lowered.

Cross-section of the cochlea (left), with illustration of IHCs and OHCs (right). Used by permission of Alec Salt, Washington University School of Medicine.

Cross-section of the cochlea (left), with illustration of IHCs and OHCs (right). Used by permission of Alec Salt, Washington University School of Medicine.

Readers familiar with the anatomy of the ear know that approximately 95% of the fibers innervating the IHCs lead to the brain as afferent fibers, while only about 5% of the fibers innervating the OHCs are afferent fibers. Thus, we hear through our IHCs, and our hearing sensitivity is comparable to the calculated IHC sensitivity. The OHCs, which respond physiologically to infrasound, serve as a pathway for infrasound to reach the brain. Infrasonic signals that reach the brain are normally not perceived as sound, but are believed to stimulate centers other than auditory centers, resulting in perceptions that may be unfamiliar and disturbing.

Similar pathways to various centers of the brain also exist through the vestibular, or balance, mechanisms of the inner ear, meaning that it is biologically plausible for infrasound to produce the variety of sensations described by Pierpont, sensations such as pulsation, annoyance, stress, panic, ear pressure or fullness, unsteadiness, vertigo, nausea, tinnitus, general discomfort, memory loss, and disturbed sleep.

Salt and colleagues have also found that when higher-pitched sounds (150-1500 Hz) are present, they can suppress infrasound. This means that the ear is most sensitive to infrasound when higher-frequency sounds are absent. This occurs at night when wind turbine noise is present, ambient sound levels are low, and higher-pitched sounds are attenuated by walls and other physical structures.

Another relatively recent discovery is that there is likely a cause-effect relationship between AHEs and ILFN that mirrors that occurring in motion sickness. An experiment in the late 1980s, conducted using training-mission scenarios with Navy pilots, showed that motion sickness was associated with significant amounts of acoustic energy inside the flight cabin over the frequency range from just under 1 Hz to as low as 0.05 Hz (the nauseogenic range). Maximum sensitivity occurred at approximately 0.2 Hz. That experiment resulted in the conclusion that flight simulator sickness may be, to a significant extent, a function of exposure to infrasonic frequencies. This phenomenon is akin to seasickness, except that the acoustic energy causes nausea without body movement or visual stimulation.
wind noise

As utility-scale wind turbines increase in size and power, the blade-pass frequency goes increasingly deeper into the nauseogenic zone.

As utility-scale wind turbines increase in size and power, the blade-pass frequency goes increasingly deeper into the nauseogenic zone.

Dr. Paul Schomer, nationally and internationally known for his work in acoustics and acoustic-standards development, has suggested that because the Navy test subjects responded to acoustical/vibratory energy with symptoms similar to motion sickness, many of the similar symptoms reported by people living near IWTs can be explained by exposure to infrasound from wind turbines at frequencies similar to those observed in the Navy’s test environment. Persons affected by wind turbine noise appear to be responding directly to acoustic stimulation of the same nerves and organs affected in that experimental environment.

DATA SUPPORT REPORTED SYMPTOMS AS BIOLOGICALLY PLAUSIBLE

These research efforts of Salt and colleagues, Schomer, and others are leading the way in establishing the biological plausibility of the harmful effects of ILFN generated by wind turbines.

Dr. Salt dismisses the common perception that what we can’t hear can’t hurt us and has stated unequivocally that “Wind turbines can be hazardous to human health.”

Decisions regarding the siting of industrial wind turbines deserve careful attention to limiting noise exposure levels in community residents through specified restrictions on either distance or noise levels, or both. The right of the public to enjoy health and well-being should be paramount to the economic and political interests of the wind industry and governmental bodies. These rights need to be protected on a proactive, and not just on a retroactive, basis. Industrial-scale wind turbines should be sited only at distances from residents that are sufficient to minimize sleep disturbance and that do not put them at risk for a variety of other serious health problems.

Jerry Punch is an audiologist and professor emeritus at Michigan State University in the Department of Communicative Sciences and Disorders. Since his retirement in 2011, he has become actively involved as a private audiological consultant in areas related to his long-standing interest in community noise.

Richard James is an acoustical consultant with over 40 years of experience in industrial noise measurement and control. He served as an adjunct instructor in Michigan State University’s Department of Communicative Sciences and Disorders from 1985-2013 and currently serves as an adjunct professor in Central Michigan University’s Department of Communication Disorders.

[Originally published at Hearing Health & Technology Matters, Nov. 18, 2014]

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Date added:  November 12, 2014
Health, Noise, TechnologyPrint storyE-mail story

Negative health impact of noise from industrial wind turbines: The evidence

Author:  Punch, Jerry; and James, Richard

This post, the second of three installments, reviews the major research findings linking low-frequency noise and infrasound from industrial wind turbines with effects on health and quality of life.[1] [Part 1: Some Background; Part 3: How the Ear and Brain Process infrasound.]

Evidence that industrial wind turbines (IWTs) negatively impact human health is vast and growing. Although that evidence acknowledges that the exact exposures needed to impact health and the percentage of the affected population are still unknown, there is indisputable evidence that adverse health effects (AHEs) occur for a nontrivial percentage of exposed populations. Here, we give an overview of that evidence.[2]

Wind turbine noise is not known to cause hearing loss. Interestingly, though, individuals who have hearing disorders may be more susceptible than persons with normal hearing to AHEs from wind turbine noise, and people who are deaf can suffer the same ill effects as those who have normal hearing when exposed to wind turbine noise. The latter finding supports the view that infrasound, not just the audible whooshing, low-frequency noise emitted from wind turbines, is the cause of many of the health complaints.

The anecdotal evidence, documented on internet blogs, in newspaper articles, in expert testimony in legal proceedings, and recently in the documentary movies Windfall and Wind Rush, is compelling and illustrative of the similarity in symptoms. These adverse symptoms appear when people are exposed to operating wind turbines, and disappear when the turbines stop operating. These observations resemble single-subject research experiments, in which individuals serve as their own controls while being subjected to alternating conditions or treatments. Dr. Carl Phillips, noted epidemiologist, describes the use of adverse event reporting as a first step in establishing the existence, prevalence, and spread of a variety of health conditions, as well as adverse reactions to such agents as medications and environmental pollutants.

Reports that many families abandon their homes after IWTs begin operation make the anecdotal evidence particularly compelling.

Studies conducted in Denmark, the Netherlands, Germany, and Sweden, where residents have many decades of experience with IWTs, collectively indicate that wind turbine noise differs from and is more annoying than other sources of noise, including community, transportation, and industrial sources.

These differences are attributed to the substantial infrasound and low-frequency noise (ILFN) produced by the turbines. Such sounds are not easily masked by other environmental sounds, including wind noise.

As the blade passes the tower, infrasound pulses are emitted, while more audible low-frequency sounds are produced by blade movement. Used by permission of Esther Wrightman, Ontario.

As the blade passes the tower, infrasound pulses are emitted, while more audible low-frequency sounds are produced by blade movement. Used by permission of Esther Wrightman, Ontario.

Annoyance from turbine noise at 35 dBA corresponds to the annoyance reported for other common community-noise sources at 45 dBA. The World Health Organization (WHO) has concluded that observable effects of nighttime, outdoor noise levels of 40 dBA or higher will lead to diminished health. This also occurs when levels inside homes (especially bedrooms) rise above 30 dBA or contain non-steady and/or low-frequency noise.

Yet, the wind industry commonly promotes 50 dBA as an appropriate limit for homes, even though the World Health Organization has identified such high levels as a cause of serious health effects.[3]

HEALTH EFFECTS OF WIND TURBINE NOISE

By far, sleep disturbance is the most common complaint of families living near wind turbines. Prolonged lack of sleep affects our capacity to learn and negatively affects our memory, temperament, heart health, stress levels, and hormones that regulate growth, puberty and fertility. It can also lead to high blood pressure, changes in heart rate, and an increase in heart disease, as well as weight gain and lowered immunity to disease. These symptoms have regularly been reported by individuals who live near IWTs.

In a controlled clinical study, residents who lived within 1.4 kilometers, or 0.87 mile, of IWTs exhibited greater sleep disturbance and poorer mental health than those living at distances greater than 3.3 kilometers, or 2 miles, away, and scores on sleep and mental-health measures correlated well with noise exposure levels. Another study found lower quality of life (QoL) in residents living within 2 kilometers of a turbine installation than at longer distances. Abandonment of homes near wind turbines has been associated primarily with disruptions to sleep and QoL.

Nina Pierpont, MD, PhD,[4] and a practicing pediatrician, coined the term Wind Turbine Syndrome (WTS) in 2009 to describe the symptoms she observed in a cohort study of 38 members of 10 families. Those symptoms include: sleep disturbance; headache; Visceral Vibratory Vestibular Disturbance (VVVD); dizziness, vertigo, unsteadiness; tinnitus; ear pressure or pain; external auditory canal sensation; memory and concentration deficits; irritability and anger; and fatigue and loss of motivation. Although her case-series report, published as a book, has often been maligned by the wind industry as being non-scientific, an increasing body of scientific evidence supports her observations and their links to exposure to wind turbines. Dr. Robert McMurtry, a well-respected Ontario physician, recently proposed specific diagnostic criteria for a case definition of AHEs due to IWTs.

INDUSTRY REACTS TO CLAIMS

In 2009, a joint report of the American and Canadian Wind Energy Associations (AWEA/CanWEA) established the basis for arguments routinely used by wind energy advocates to persuade the public and public officials that IWTs present no health risks. The panel members who produced the report were handpicked by AWEA’s acoustical consultant, and all had prior positions on noise from wind turbines favorable to the industry.

The report concluded that exposure to wind turbine noise has no direct adverse physiological or health consequences, a conclusion shown to be erroneous by multiple lines of evidence, at least several of which were established prior to the report. The report’s major weaknesses were its comparisons of wind turbine noise levels to those produced by other environmental noises and its embrace of the A-weighted measurement scale as valid, even though that scale minimizes low-frequency sound and completely excludes infrasound.

Several scholarly researchers have rejected the AWEA/CanWEA report as misleading and unscientific. One of the report’s co-authors, Dr. Geoff Leventhall, whose own research demonstrates that ILFN leads to various health symptoms, attributes those symptoms to extreme psychological stress from low-frequency noise, but does not acknowledge that IWTs also cause such symptoms. He argues that the ILFN emitted by wind turbines falls below the threshold of hearing, claiming that what we can’t hear can’t hurt us—a topic we will address in our final installment.

Jerry Punch is an audiologist and professor emeritus at Michigan State University in the Department of Communicative Sciences and Disorders. Since his retirement in 2011, he has become actively involved as a private audiological consultant in areas related to his long-standing interest in community noise.

Richard James is an acoustical consultant with over 40 years of experience in industrial noise measurement and control. He is an adjunct instructor in Michigan State University’s Department of Communicative Sciences and Disorders and an adjunct professor in Central Michigan University’s Department of Communication Disorders.

[1] Part 1: Some Background. Part 3: How the Ear and Brain Process Infrasound.
[2] Of note: the authors of this series are currently preparing a comprehensive, fully referenced paper for publication elsewhere.
[3] Night Noise Guidelines for Europe set limit at 40 dBA.
[4] MD degree earned from Johns Hopkins and PhD from Princeton.

[Originally published at Hearing Health & Technology Matters, Nov. 11, 2014]

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Date added:  November 7, 2014
Canada, Health, Noise, Ontario, Prince Edward IslandPrint storyE-mail story

Self-reported and objectively measured health indicators among a sample of Canadians living within the vicinity of industrial wind turbines

Author:  Michaud, David; Keith, Stephen; et al.

This is the detailed description of the methodology used for the Health Canada/Statistics Canada “Wind Turbine Noise and Health Study”, the preliminary results of which are summarized at www.hc-sc.gc.ca/ewh-semt/noise-bruit/turbine-eoliennes/summary-resume-eng.php.

From the summary of results:

The following were not found to be associated with WTN exposure:

  • self-reported sleep (e.g., general disturbance, use of sleep medication, diagnosed sleep disorders);
  • self-reported illnesses (e.g., dizziness, tinnitus, prevalence of frequent migraines and headaches) and chronic health conditions (e.g., heart disease, high blood pressure and diabetes); and
  • self-reported perceived stress and quality of life.

While some individuals reported some of the health conditions above, the prevalence was not found to change in relation to WTN levels.

But:

Statistically significant exposure-response relationships were found between increasing WTN levels and the prevalence of reporting high annoyance. These associations were found with annoyance due to noise, vibrations, blinking lights, shadow and visual impacts from wind turbines. In all cases, annoyance increased with increasing exposure to WTN [wind turbine noise] levels. …

  • WTN annoyance was found to be statistically related to several self-reported health effects including, but not limited to, blood pressure, migraines, tinnitus, dizziness, scores on the PSQI, and perceived stress.
  • WTN annoyance was found to be statistically related to measured hair cortisol, systolic and diastolic blood pressure.
  • The above associations for self-reported and measured health endpoints were not dependent on the particular levels of noise, or particular distances from the turbines, and were also observed in many cases for road traffic noise annoyance.
  • Although Health Canada has no way of knowing whether these conditions may have either pre-dated, and/or are possibly exacerbated by, exposure to wind turbines, the findings support a potential link between long term high annoyance and health.
  • Findings suggest that health and well-being effects may be partially related to activities that influence community annoyance, over and above exposure to wind turbines.

Download original document: “Self-reported and objectively measured health indicators among a sample of Canadians living within the vicinity of industrial wind turbines: Social survey and sound level modelling methodology”

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