Resource Documents: Noise (538 items)
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.
Analysis of aerodynamic sound noise generated by a large-scaled wind turbine and its physiological evaluation
Author: Inagaki, T.; Li, Y.; and Nishi, Y.
Abstract — Aerodynamic noise generated from a modern large-scale wind turbine was measured and analyzed from an engineering point of view. The measurement items were the sound, the sound pressure level (including the infrasound with extremely low-frequency band) and the corresponding physiological evaluation. Fifteen test subjects received various sound stimuli, including the recorded aerodynamic noise and a synthetic periodical sound, [and] were examined with an electroencephalogram as a physiological evaluation. It was observed from the mapping patterns of brain waves that alpha₁ rhythm, which indicates a relaxed and concentrated state, after the sound stimulus with the frequency band of 20 Hz, showed the lowest value among the other cases. That is, the test subjects cannot keep relaxed and their concentration after hearing the sound stimulus at the frequency band of 20 Hz. The induced rate of alpha₁ rhythm almost decreased when the test subjects listened to all the sound stimuli, and further decreased with decreased frequency. Meanwhile, beta₁ rhythm, which shows a strain state, after the sound stimulus with the frequency band of 20 Hz showed the highest value among the other cases. Therefore, the infrasound (e.g., low frequency and inaudible for human hearing) was considered to be an annoyance to the technicians who work in close proximity to a modern large-scale wind turbine.
T. Inagaki, Y. Li, Y. Nishi
Department of Mechanical Engineering, College of Engineering, Ibaraki University, Hitachi-shi, Ibaraki-ken, Japan
International Journal of Environmental Science and Technology
June 2015, Volume 12, Issue 6, pp 1933-1944
Author: Swinbanks, Malcolm
The author first became aware of the adverse health problems associated with infrasound many years ago in 1974, when an aero-engine manufacturer approached him to consider the problems that office personnel were experiencing close to engine test facilities. He had been conducting research into the active control of sound, and the question was posed as to whether active sound control could be used to address this problem. At that time, this research was in its infancy, and the scale of the problem clearly lay outside practical implementation. Five years later, however, the author was asked to address a related problem associated with the low-frequency noise of a 15,000SHP ground-based gas-turbine compressor installation, having a 40 foot high, 10 foot diameter exhaust stack. This problem was of a more tractable scale, and the author and his colleagues successfully reduced the low-frequency noise of the installation by over 12dB. He subsequently was requested to address a similar installation of significantly greater size and power, again with accurately predicted results.
As a consequence of this and subsequent work, the author has gained considerable experience of the disturbing effects of low-frequency noise and infrasound. So when he first became aware of the nature of adverse health reports from windfarm residents, they were immediately recognisable as effects with which he had been familiar for as many as 35 years.
Since late 2009, the author has lived part-time within a Michigan community where windturbines have been increasingly deployed. Consequently he has had significant interaction with residents whose lives and well-being have been damaged, and moreover has experienced the associated very severe effects directly, at first hand. His resultant perspective is thus based on both detailed theoretical analysis, and extensive personal, practical experience.
M.A. Swinbanks, MAS Research Ltd, Cambridge, U.K.
Presented at Wind Turbine Noise 2015, Glasgow, 20–23 April
Author: Neville, Tania
There is a growing body of information, data, opinion, litigation and complaint surrounding the proliferation of industrial wind turbine developments worldwide. Governments have been quick to adopt the purported clean energy benefits of such development but slow to advance and implement appropriate guidelines, enforcement mechanisms and a means to examine what appears to be a growing public health issue related to noise.
This paper reviews case law to date and current health and independent noise data that indicate litigation in common law for private nuisance and negligence may succeed based on the common complaints associated with living near industrial wind turbines, that is, noise, health problems and property devaluation.
Planning and guidelines in relation to these developments now offer certainty to developers but have reduced the input of locals and local government. It is considered that the global view cannot override well established common law principles and that those impacted by these developments locally, should be able to seek redress in the courts.
Government responses to global problems should not result in harm or damage to individuals or small communities.
Download original document: “Industrial wind energy: When planning & guidelines fail the locals; Is common law an instrument to protect neighbours? A discussion on nuisance and negligence actions relating to noise and health”
Author: Evans, Alun
WIND TURBINES AND HEALTH
According to the World Health Organisation’s recent report, ‘Night Noise Guidelines for Europe,’ environmental noise is emerging as one of the major public health concerns of the twenty-first century. It observes that, “Many people have to adapt their lives to cope with the noise at night,” and the young and the old are particularly vulnerable. This is because hearing in young people is more acute and, in older people, a loss of hearing of higher sound frequencies renders them more susceptible to the effects of low frequency noise. It is a particularly troublesome feature of the noise generated by wind turbines due to its impulsive, intrusive and incessant nature. A recent systematic review considered 154 published studies, eventually including 18 on the basis that they examined the association of wind turbines and human distress and were published in peer-review journals in English from 2003-2013. All found between wind turbines and human distress with levels of evidence of four and five (Bradford Hill Criteria). In addition, two of these studies showed a dose response relationship between distance from wind turbines and distress. Thus there is a consistent relationship between the proximity of turbines and human distress.
The major adverse health effects caused by wind turbines seem to be due to sleep disturbance and deprivation with the main culprits identified to account for this being loud noise in the auditory range, and low frequency noise, particularly infrasound. This is inaudible in the conventional sense, and is propagated over large distances and penetrates the fabric of dwellings, where it may be amplified. It is a particular problem at night, in the quiet rural settings most favoured for wind farms, because infrasound persists long after the higher frequencies have been dissipated.
Sleep is a physiological necessity and the sleep-deprived are vulnerable to a variety of health problems. particularly Cardiovascular Disease in which nocturnal noise is an important factor. Sleep deprivation in children is associated with increased bodyweight, which is known to ‘track’ into later life, and predisposes to adult disease. That is why “Encouraging more sleep” is a sensible target in the current Safefood/HSE/NI Public Health Agency campaign to prevent obesity in children. Sleep deprivation also interferes with learning causes memory impairment because memory is laid down and reinforced during both Slow Wave and Rapid Eye Movement phases of sleep, and in mice it has been shown that sleep has a key role in promoting learning-dependent synapse formation and maintenance on selected dendritic branches, which contribute to memory storage.
There is an ever-mounting volume of research to show that sleep is essential for the brain and the physiological well-being of the entire body. For example, during sleep, neurotoxins are removed from the brain. Recently an association between sleep deprivation and loss of brain volume has been demonstrated. This study was based on serial MRI scans carried out in 147 community-dwelling adults.
Sleep deprivation is associated with an increased likelihood of developing a range of chronic diseases including Type II Diabetes, cancer (eg breast with shift work), Coronary Heart Disease, and Heart Failure. Although the quality of the data are mixed, those on Heart Failure reported recently from the HUNT Study are quite robust as they are based on 54,279 Norwegians free of disease at baseline (men and women aged 20-89 years). A total of 1412 cases of Heart Failure developed over a mean follow-up of 11.3 years. A dose-dependent relationship was observed between the risk of disease and the number of reported insomnia symptoms: i) Difficulty in initiating sleep; ii) Difficulty in maintaining sleep; and, iii) Lack of restorative sleep. The Hazard Ratios were ‘0’ for none of these; ‘0.96’ for one; ‘1.35’ for two; and, ‘4.53’ for three; this achieved significance at the 2% level. This means that such a result could occur once by chance if the study were to be repeated 50 times, Significance is conventionally accepted at the 5% level.
Another important, recent study is MORGEN which followed nearly 18,000 Dutch men and women, free of Cardiovascular Disease at baseline, over 10-14 years. In this period there were 607 events: fatal CVD, non-fatal Myocardial Infarction and Stroke. Adequate sleep, defined as at least seven hours, was a protective factor which augmented the benefits conferred by the absence of four traditional cardiovascular risk factors. For example, the benefit of adequate sleep equalled the protective contribution of not smoking cigarettes. Given that cigarette smoking is such a potent risk factor for Cardiovascular Disease, this result is striking. The findings built on earlier ones from the MORGEN study. It seems that adequate sleep is important in protecting against a range of Cardiovascular Diseases which result when arteries of different sizes are compromised: large (coronary, cerebral) arteries in heart attacks and stroke, small arteries (arterioles) in heart failure. The mechanisms are obscure, but it is known for example that exposing mice to stress activates hematopoietic stem cells, ie affects the immune system and accelerates atherosclerosis.
All of these studies share the weakness that they are ‘observational’ as opposed to ‘experimental’ and, as such, their results do not constitute ‘proof.’ We now have the evidence of an experimental study carried out in human volunteers which shows that the expression of a large range of genes is affected by sleep deprivation of fairly short duration. This might be the key to understanding why the health effects of sleep deprivation are so diverse. It could also shed light on the ‘Wind Turbine Syndrome (WFS),’ a cluster of symptoms which include sleep disturbance, fatigue, headaches, dizziness, nausea, changes in mood and inability to concentrate. In this condition infrasound is a likely causal agent. Another report from HUNT has examined insomnia in almost 25,000 persons and has demonstrated it to a robust risk factor for incident physical and mental disease, including several features of WFS.
This group has now shown in another small intervention study that mistimed sleep desynchronized from the central circadian clock has a much larger effect on the circadian regulation of the human transcriptome (i.e., a reduction in the number of circadian transcripts from 6.4% to 1% and changes in the overall time course of expression of 34% of transcripts). This may elucidate the reasons for the large excess of cardiovascular events associated with shift work found in a meta-analysis of over 2 million subjects in 34 studies. The results demonstrate that any interference in normal sleeping patterns is inimical to cardiovascular health.
The old admonition that ‘What you can’t hear won’t harm you,’ sadly isn’t true. It is now known that organ of Corti in the cochlea (inner ear) contains two types of sensory cells: one row of inner hair cells which are responsible for hearing; and, three rows of outer hair cells which are more responsive to low frequency sound. The infrasound produced by wind turbines is transduced by the outer hair cells and transmitted to the brain by Type II afferent fibres. The purpose is unclear as it results in sleep disturbance. Perhaps it served some vital function in our evolutionary past which has persisted to our detriment today? In fact, many animals use infrasound for communication and navigation. This could well have a genetic basis as it is only a minority, albeit a sizable one, which is affected. This may well be the group which is also liable to travel sickness. Schomer et al have now advanced the theory that as wind turbines increase in size they increasingly emit infrasound with a frequency below 1Hz (CPS). Below this frequency the otoliths in the inner ear respond in an exaggerated way in a susceptible minority who will suffer symptoms of the Wind Farm Syndrome. Previously it was thought that the brain was only under the control of electrical and biochemical stimuli but there is new evidence that it is sensitive, in addition, to mechanical stimuli.
The problem of infrasound and low frequency noise was well-recognised in a report by Casella Stanger, commissioned by DEFRA in 2001, and since ignored: “For people inside buildings with windows closed, this effect is exacerbated by the sound insulation properties of the building envelope. Again mid and high frequencies are attenuated to a much greater extent than low frequencies.” It continued: “As the A-weighting network attenuates low frequencies by a large amount, any measurements made of the noise should be with the instrumentation set to linear.” It drew heavily upon the DOE’s Batho Report of 1990. In fact, these problems had already been elucidated and the measurement issues addressed in a trio of papers by Kelley (et al) in the 1980s.
This research again has been ignored or forgotten so the problem continues to be seriously underestimated. When measured using a tool which can detect it, levels of infrasound and low frequency noise are disturbingly high, with ‘sound pressure levels’ greater than previously thought possible. It has also been demonstrated that infrasonic noise interferes with the micro- mechanics of the human inner ear.
There were other important studies which were carried out in the 1980s which appear to have been forgotten. Danielsson and Landstrom carried out a study in 20 healthy male volunteers who were bombarded with Infrasound for varying periods. Just 30 minutes bombardment with 125 dB at 16 Hz resulted in a mean 8 mm increase in diastolic blood pressure. On the other hand systolic BP was not affected whereas the Pulse Pressure decreased.
Scientists at the University of Toronto Institute for Aerospace and the University of Waterloo found a variability in response in volunteers exposed to Infrasound. The adverse responses of some individuals closely resembled motion sickness. They postulated that individual differences in the reaction to Infrasound might be explained by variability of inner-ear structure or central adaptive mechanisms.
There are a number of other adverse effects associated with sleep deprivation. Tired individuals are more likely to have road traffic accidents and injure themselves while operating machinery. In addition, wind turbines can, and do, cause accidents by collapsing, blade snap, ice throw, and even going on fire. They induce stress and psychological disorder from blade flicker, which also has implications for certain types of epilepsy and autism. Even the current planning process, with its virtual absence of consultation, is stress inducing, as is the confrontation between land owners, who wish to profit from erecting turbines, and their neighbours who dread the effects. Finally, wind turbines considerably reduce the value of dwellings nearby and this has a negative long term effect on their owners’ and their families’ health. On top of this, increasing numbers of families will be driven into fuel poverty by spiralling electricity costs which are subsidising wind energy.
‘Wind Turbine Noise’ was reviewed in an editorial in the British Medical Journal in 2012. The authors concluded that “A large body of evidence now exists to suggest that wind turbines disturb sleep and impair health at distances and noise levels that are permitted in most jurisdictions.” This remains the case today. The Public Health Agency has dismissed this editorial as falling short of a ‘systematic review,’ which is fair enough, given the constraints of the format, yet ignores at least two recent systematic reviews.
Interestingly, the Frey and Hadden review records the fact that in 1978 the British Government was found guilty in a case taken to Europe by the Irish Government of applying five techniques, including ‘Subjection to Noise’ and ‘Deprivation of Sleep.’ These were used in Ulster by the British Army to ‘encourage’ admissions and to elicit information from prisoners and detainees. They amounted to humiliating and degrading treatment, ie torture. This verdict was subsequently overturned and reduced to Inhuman and Degrading Treatment. It is ironic that the Irish is currently backing the pursuit of this case by ‘The Hooded Men’ when it is sanctioning the imposition of Noise and Sleep Deprivation on its rural citizens through its current setback guidelines
The Public Health Agencies in the UK are now relying on a document published in April 2013 which is also not peer-reviewed. It was written by a group of acousticians at the University of Salford, which begs the question as to why such a group was selected to give advice on health issues. Since acousticians derive a significant proportion of their income from the wind industry, their scientific objectivity might be open to question. Similarly, if a profession, which worked closely with the tobacco industry, was asked to report on health, questions would be asked.
The wind industry has at times acted in a way that is reminiscent of the tobacco industry in the past. Recently a Vestas Powerpoint presentation from 2004 has surfaced demonstrating that Vestas knew a decade ago that safer buffers were required to protect neighbours from wind turbine noise. They knew their pre-construction noise models were inaccurate and that “we know that noise from wind turbines sometimes annoys people even if the noise is below noise limits.” Some of this is due to the methods they use to measure noise. Presenting mean amplitude data means that 50% of the peak noise is disguised.
In 2011 the CEO of Vestas wrote to the Danish Minister of Environment admitting that it was not technically possible to produce wind turbines which produced less noise. Similarly, we are repeatedly told that modern turbines are quieter and produce less Infrasound and low frequency noise which in reality is the reverse of the case.
The Salford Report concludes that there is “some evidence for sleep disturbance which has found fairly wide, though not universal, acceptance.” The increasing weight of evidence of sleep deprivation’s association with several chronic diseases is totally ignored. The authors of the report are at pains to deny any ‘direct’ health effects. In terms of prevention any differentiation between ‘direct’ and ‘indirect’ is irrelevant: the introduction of iodine supplementation in milking cattle to improve their “reproductive performance” during the 1960s indirectly led to a reduction in endemic goitre in humans. This was thanks to the unforeseen spillover of iodine into milk and dairy products.
In 2008 the distinguished American acoustic engineers, George Kamperman, and Richard James posed the question, “What are the technical options for reducing wind turbine noise emission at residences?” They observed that there were only two options: i) Increase the distance between source and receiver; or, ii) reduce the source sound power emission. They added that neither solution is compatible with the objective of the wind farm developer to maximise the wind power electrical generation within the land available.
Although the associations between noise pollution and ill health can be argued against, and there are gaps in our knowledge, there is sufficient evidence to cause grave misgivings about its safety. Further research, supported by adequate funding, remains necessary. Good and caring Government should entail acting with greater caution when its policies could jeopardise the health and human rights of its people. It is essential that the ‘Primum non nocere,’ or ‘Precautionary’ principle should be applied. Another recent review on the ‘Cardiovascular effects of environmental noise exposure’ quotes the Nobel Prize winning microbiologist, Robert Koch. As early as 1910, Koch predicted, “One day man will have to fight noise as fiercely as cholera and plague.”
There is another aspect of the deployment of turbines in Ireland and which also impinges on human health. The siting of turbines on upland blanket bogs, and on lowland raised bog has the effect of increasing carbon dioxide emissions. There is mounting evidence that peatlands provide one of the best repositories of carbon dioxide on the planet. In Ireland alone it is estimated that the remaining near-intact peatlands store the equivalent of 200.000 tonnes a year. Unfortunately this process is reversed when the peatlands are degraded, as they have been on a grand scale. As a consequence they make a net contribution to greenhouse gas emissions which is running at the equivalent of 9.6 million tonnes of carbon dioxide released into the atmosphere every year. An article in the current ‘Natural World’ stresses the importance of peatlands as carbon dioxide sinks. It describes the vast lengths being gone to in Yorkshire to restore the damage done to the peatlands by a massive drainage programme undertaken between 1950 and 1980 to press more of the land into agricultural service. The article observes that “the draining and burning of South East Asian peat forests [sic] contributes eight per cent of the world’s carbon emissions as damaged bogs release their once-safely stored carbon to the atmosphere.” It goes on to quote the Head of the UN Environment Programme, who pronounced peatland restoration, “a low-hanging fruit, and the most cost- effective of options for mitigating climate change.” In fact “peatland restoration, … is a critical part of the world campaign to stop catastrophic climate change.”
A recent scientific paper reviewing the economics of such a policy has found that the carbon dioxide release involved in manufacturing and erecting turbines on blanket bogs is never recovered. The authors conclude: “Given the clear advantages in terms of carbon payback time of locating windfarms on mineral soils, and the marginal future savings of carbon by locating windfarms on peats, construction of windfarms on un-degraded peatlands is best avoided as far as practicable.” In short, erecting windfarms on blanket bog is likely to exacerbate Global Warming, and, in consequence, everyone’s health will suffer thanks to climate destabilization.
Worryingly, it is now predicted that the proliferation of wind farms will itself have an important contribution to make to climate change. Employing wind turbines to meet 10% or more of global energy demand could cause surface warming exceeding 1°C over land installations. A three-dimensional climate model used by Wang and Prinn forecasts that impacts resulting in significant warming or cooling can occur even in places remote from wind farms. Alterations of the global distributions of rainfall and clouds can also occur.
In conclusion, there are serious adverse health effects associated with noise pollution generated by wind turbines. It is essential that separation distances between human habitation and wind turbines are increased. There is an international consensus emerging for a separation distance of 2 km, indeed some countries are opting for 3 km. …
Professor Emeritus Alun Evans, February 2015