History of Research
There is a long history of acoustic and clinical research into the adverse health effects of noise on health (and sleep), including audible noise, infrasound, low frequency noise and vibration.
This has informed documents such as the various acoustic standards (e.g. whole body vibration), World Health Organisation (WHO) documents relating to community noise, night time noise and the burden of illness from environmental noise, and Australia’s own EnHealth document of 2004.
An excellent and detailed recent history of the research into wind turbine noise and other sources of infrasound and low frequency noise can be found in Rick James article published in the Bulletin of Science and Technology in 2012, entitled “Warning signs that went unheard”.
Another very useful summary of the knowledge available with respect to what was known about low frequency noise impacts on health ten years ago was a literature review by Professor Geoffrey Leventhall in 2003. Leventhall discusses the known connections between low frequency noise and physiological stress (eg in sleeping children), and acknowledges that if people are removed from the noise they will improve. In the conclusions he also acknowledges the additional stress and distress caused when people affected by noise are not understood by their health care providers.
Finally a brief literature review “Infrasound, a brief toxicological review” from the US National Institute of Environmental Health Sciences (NIEHS) in 2001 contains some useful animal and human research which clearly indicate there is animal research evidence of physiological stress effects and damage to tissue including heart muscle, with exposure to acute high ‘doses’ of infrasound.
What is less clear is the effect of chronic exposure to lower doses of infrasound, as there appears to be almost no research data in the public domain examining this issue in either animals or humans. However there is one study in the NIEHS infrasound literature review (#58 by Dadali et al on page 25) investigating chronic exposure of two groups of rats to infrasound at 100 dB of 8 Hz for 3 hours per day for 60 days. One group was given antioxidants, and their organ damage was less than those rats in the control group.
Symptoms from wind turbines documented in the UK, 2003
In 2003 Dr Amanda Harry, a rural general practitioner from Cornwall, UK, was the first medical practitioner to describe the health problems being reported by rural residents after the start up of a wind energy development.
Dr Amanda Harry conducted a survey on some of her longstanding patients and others she identified from elsewhere in the UK who developed disturbing new symptoms after a wind project commenced operation near their homes. She then wrote a ground breaking report on the issue.
Dr Harry has added multidisciplinary depth to her work through:
- Additional post graduate training in Ear, Nose and Throat disorders, and
- The advice she received from others with experience in related fields including:
- Dr David Manley, Acoustics
- Dr Mariana Alves-Pereira, Biomechanical Engineering, and
- Professor Ralph Katz, Epidemiology.
Reports emerge from Victoria, Australia, 2004
The second medical practitioner to investigate was Dr David Iser, a longstanding rural general practitioner from Toora in Victoria, Australia.
In 2004, Dr Iser contacted Dr Harry and used her survey form with his patients who had been recently exposed to a new wind turbine development. He conducted a small local population survey and found similar pathology was reported.
Dr Iser wrote to health authorities and politicians at that time expressing his concern but there was no response from health authorities, and no further investigation.
Some sick residents were silenced with confidentiality clauses
Over time, many of the seriously ill residents in the hills behind Toora in Victoria moved out, and their homes were bulldozed, relocated, or left unoccupied. A number of the residents were bought out by the wind developer, and signed agreements containing confidentiality clauses. As a result, these people could not speak publicly about their health problems, effectively keeping the problems hidden from public view. Slater & Gordon, the legal firm acting for these residents, publicly confirmed this practice of using confidentiality clauses in these circumstances in a letter to the Australian newspaper, on May 4, 2012.
This practice of preventing sick people from speaking about their health problems and the direct correlation with exposure to operating wind turbines has also been reported at other wind developments in Australia, and in the UK, the USA, and Canada. Residents impacted adversely by low frequency noise and vibration from mining and gas fired power stations in other locations in Australia have also signed these “gag” agreements in exchange for property buyouts.
Dr Nina Pierpont expands our knowledge, 2009
The third Medical Practitioner to investigate was Dr Nina Pierpont, who:
- Is a paediatrician from the USA
- Was a former assistant Clinical Professor in Paediatrics, at Columbia University, and a current Fellow of the American Academy of Paediatrics, and
- Had a prior research Masters and PhD in behavioural ecology (Princeton) and had conducted research examining animal behaviour in populations, so was familiar with research methodologies and statistical analyses not generally used in epidemiology, but which were ideally suited to examine this particular problem.
Dr Pierpont spent three years conducting a detailed and methodical case series cross-over study, which was extensively peer reviewed by experts in their respective fields, prior to its publication. These peers included Professors of Otolaryngology (Ear Noise and Throat specialists and researchers), a Neurologist, an Epidemiologist and a Behavioural Ecologist. Like Dr Harry, she also consulted with a variety of experts, including two experienced Noise Engineers from the USA – Mr Rick James and Mr George Kamperman.
The executive summary of Dr Pierpont’s study, ‘Wind Turbine Syndrome’ was self-published, as it was too long for inclusion in a medical journal, and was impossible to condense. Those who seek to dismiss Dr Pierpont’s findings frequently misleadingly assert that her study is not peer reviewed. This is untrue. The comments of her reviewers can be viewed here.
Peer reviewers of Dr Pierpont’s study include the following:
- Professor Jerome S Haller, former Professor of Neurology & Paediatrics, Albany Medical College, Albany, New York
- Professor Joel F Lehrer, Clinical Professor of Otolaryngology, (Ear Nose and Throat) University of Medicine & Dentistry of New Jersey, formerly Professor of Otolaryngology, Mount Sinai Medical School of Medicine, New York
- Professor Owen Black, Otolaryngologist & researcher with NASA and the US Navy
- Professor Ralph V Katz, Professor & Chair, Department of Epidemiology and Health promotion, New York University College of Dentistry, New York
Further details of Dr Pierpont’s study, including the executive summary and peer reviews are available from our Resources section, the Wind Watch website and Dr Pierpont’s website. Her book, ‘Wind Turbine Syndrome’, includes:
- A report for clinicians
- The raw data, including extensive case data and descriptions of symptoms by the subjects, and
- A report for people unfamiliar with medical and acoustic terminology
Dr Pierpont’s study, like a PhD dissertation, is too long for inclusion in a journal, but has been accepted by fellow clinicians looking after sick residents as an important and useful piece of research. Testament to the usefulness of Dr Pierpont’s research is the way sick residents and their treating family doctors have found it a valuable and credible source of information, and the number of languages into which it has been translated.
In addition, British Acoustician Professor Geoffrey Leventhall, who has worked closely with the wind industry, has acknowledged on a number of occasions, including during a presentation to the NHMRC that the symptoms Dr Pierpont listed are well known to acousticians to occur with exposure to low frequency noise. Historically the acoustic engineers have called the symptoms ‘annoyance’.
The Society for Wind Vigilance is established, January 2010
Professor Robert McMurtry is another Medical Practitioner to have directly investigated the reported health problems in wind turbine neighbours and as a result of his concern established the Society for Wind Vigilance in January 2010, together with another well regarded Canadian Health professional Ms Carmen Krogh.
Professor McMurtry is an extremely highly regarded Canadian medical practitioner, who amongst other roles in his career as a busy clinician was the former Dean of the Medical and Dental School of Western Ontario, and a senior adviser to a former Health Minister in Ontario.
Ms Carmen Krogh is a former senior Pharmacist for Health Canada, and former editor of the pharmaceutical compendium used by doctors and nurses across Canada.
Whilst based in Ontario, the Society (SWV) is an international organisation and includes relevant concerned professionals from health and acoustics from the UK, Canada and the USA on its board as directors or scientific advisers.
Carmen and Bob have individually spent countless hours listening to the affected residents and assisted with community education activities and both have greatly expanded our knowledge and thinking about the extent of the problems, the wide ranging consequences for the lives of rural residents, and have been tireless in their attempts to get the responsible authorities to investigate the reported health problems and take action to better protect health.
Carmen was instrumental in the WindVOiCE project survey and data analysis, which used Dr Amanda Harry’s survey as a basis for collecting preliminary data from residents living near wind developments in rural Ontario. The reported problems were consistent with those reported by Dr Harry in the UK, and Dr Iser in Australia over 5 years earlier, and included multiple episodes of home abandonment and families being split because of serious illness, as has happened in Australia at multiple sites in Victoria and South Australia particularly.
International symposium held in Ontario, Canada, October 2010
The Society for Wind Vigilance held the first international conference on the Adverse Health Effects of Wind Turbines in Ontario in October 2010, which was attended by many of the industry-independent researchers working in this area from around the world. Most of the proceedings from the symposium are available on the Society’s website. In addition to this, many of the presenters subsequently had papers published in a special edition of the Bulletin of Science and Technology. Many of the papers are also in our Resources section.
Neurophysiologist Professor Alec Salt’s contributions, 2010 onwards
Professor Salt and his co researchers including Professor Jeffrey Lichtenhan have been conducting animal model research to better understand the physiology of the inner ear (cochlear) in relation to the effects of infrasound and low frequency noise, for some years. They have identified a number of relevant pathophysiological mechanisms, which include causation of endolymphatic hydrops, excitation of subconscious pathways and amplitude modulation of audible sounds.
Most recently Professors Salt and Lichtenhan have been investigating what happens when the proportion of sound energy is down in the lowest frequencies. They have found that the inner ear is exquisitely sensitive to the lower frequencies when there is very little ambient background noise and most recently that “infrasound generated by wind turbines may cause amplitude modulation of the audible sounds”; note that this is often the basis for the complaints from neighbours.
This research is highly relevant to the problems of wind turbine noise in quiet rural environments, because many of the residents living in well insulated homes in quiet rural environments with little background noise will have and are having precisely the same problems one would expect with this stimulus of the mammalian inner ear.
Symptoms include those of vestibular disorders, and sleep disruption with repetitive sympathetic nervous system arousal via the fight flight response, which itself generates a physiological stress event each time it occurs. These are precisely the symptoms you would expect from Professor Salt’s findings and are of global importance in better understanding why these symptoms are occurring in quiet background noise environments, with a high proportion of inaudible sound energy present.
Dr Daniel Shepherd et al, Noise and Health, 2011
Dr Shepherd et al’s peer reviewed published study confirmed the negative effect of wind turbine noise on a number of parameters including sleep and health related quality of life, using internationally recognised standardised questionnaires. The data was obtained from New Zealand rural residents, comparing those living near wind turbines with those not so exposed.
Dr Michael Nissenbaum et al, Noise and Health, 2012
Dr Micheal Nissenbaum, Dr Chris Hanning and Associate Professor Jeffrey Aramini’s paper investigated sleep and general health indicators using internationally validated questionnaires at two wind developments in the USA, and utilised a case control design. Of note is their finding of a dose response effect with the data they collected.
They too found that sleep and general health was impacted adversely, with particular emphasis on mental health disorders. The size of the wind turbines in this study were smaller than those currently being built in Australia. This is one reason why the distance of reported negative effects is so much smaller in comparison to what is being reported in Australia with respect to disturbed sleep at wind developments, as identified by community noise impact surveys conducted by Wang, Morris and Schneider.
Canadian literature review of peer reviewed published evidence confirms NO studies show “no effect” February, 2013
In February 2013, two independent public health physicians from the Grey Bruce Health Unit in Ontario, Dr Ian Arra and Dr Hazel Lynn, presented the results of their comprehensive literature review. Salient features of this review are the confirmation that none of the published peer reviewed studies showed no effect from the operating wind turbines i.e. all studies showed there was relationship between the wind turbines and “human distress”.
Arra and Lynn also found there were a number of studies indicating that sleep deprivation was prevalent; some studies showing a dose response relationship between wind turbine noise and ‘the effect’ and that whilst the current levels of evidence were not strong using the accepted hierarchy of clinical evidence, still Dr Daniel Shepherd et al’s study and Dr Michael Nissenbaum et al’s study listed above were robust and of excellent quality.
Meta analysis confirms link between lack of sleep and cardiovascular disease, February 2011
Using the heirarchy of medical evidence chart on slide 8 of Arra and Lynn’s literature review, it is clear that meta analyses are top of the hierarchy of clinical evidence.
Now that the consistent reports of sleep deprivation from residents around the world are being reflected in the peer reviewed published evidence of Shepherd and Nissenbaum, as well as Australian data collected by Thorne and presented to the second Federal Senate Inquiry (see below), the timely meta analysis by Professor Capuccio can be better seen to be of vital importance and relevance. This meta analysis was tendered as evidence by the Waubra Foundation to the first Australian Senate Inquiry in February 2011 (as an attachment) .
It is well accepted that insufficient sleep will have damaging consequences for mental and physical health. In addition, the Capuccio et al meta analysis found that cardiovascular disease is also an increased health risk from insufficient sleep. Their meta analysis concludes with the following remarks:
“People reporting consistently sleeping 5 hours or less per night should be regarded as a higher risk group for cardiovascular morbidity and mortality”.
Concerns from Acousticians and Noise Engineers grow
Increasing numbers of Acousticians and Noise Engineers who are independent of the wind industry are now publicly expressing concerns at the level and severity of what has historically been called ‘annoyance’ associated with wind turbine noise.
Senior member of the acoustics profession in the USA Dr Paul Schomer (Director of Acoustics Standards) recently stated in his appendix D to the Cooperative Shirley Wind Farm Acoustic Survey report that:
“the fact that these residents largely report wind turbines as inaudible, and the reported effects on a baby, seem to rule out the illness being caused by extreme annoyance as some have suggested”.
Low frequency noise from wind turbines and other sources has long been known to cause ‘annoyance’ and other symptoms including sleep disturbance and physiological stress, as the literature review co-authored by Professor Geoffrey Leventhall in 2003 for DEFRA shows.
The World Health Organisation acknowledges ‘annoyance’ is an adverse health effect. The WHO also acknowledges that sleep deprivation is an adverse health effect. Professor Leventhall has acknowledged that sleep deprivation can be a consequence of exposure to low frequency noise and it is certainly well established that audible higher frequency noise can also cause sleep disruption.
Lack of full spectrum noise monitoring
Currently there are many reports from residents reporting that under certain conditions, the wind turbines can sound like “jet engines which never land”. There is currently no independent transparent real time monitoring of wind turbine noise anywhere in the world, unlike monitoring for airport noise monitoring. In addition, only dBA is measured, outside the home.
It is our suspicion that the audible noise guidelines are regularly exceeded by certain wind developments in Australia, but there is currently no way of proving that as the wind developers refuse to hand over the wind speed and power output data which would enable a truly independent compliance assessment with existing wind turbine noise guidelines. No wind developments have real time monitoring where the data is transparently available to all parties. It is also clear that the current wind turbine noise guidelines do not adequately protect sleep and health, because they fail to acknowledge the very quiet background noise environment, and they do not include the measurement of low frequency noise.
Professor Leventhall’s 2003 Literature Review also makes mention of the phenomena of ‘sensitisation’ whereby ongoing exposure results in worsening symptoms, and he states that provided the exposure ceases, and the person received sympathetic and informed clinical care, the affected person will improve. So whilst the precise mechanisms for this sensitisation are not yet clear, it is evident that this deterioration over time with ongoing exposure to low frequency noise was known to some acousticians back in 2003.
Clinicians are now concerned that the descriptor of ‘annoyance’ long used by engineers and acousticians is hiding some very serious pathology. This pathology has not previously been attributed to exposure to sound energy by most medical practitioners, who have been generally unaware of the known pathophysiological problems associated with infrasound, low frequency noise and vibration exposure.
NASA research, rediscovered
Early research for NASA by Hubbard and Sheppard in the 1980s showed that horizontal axis wind turbines emitted infrasound and low frequency noise. A detailed history of this and other research can be found in Mr Rick James’ article attached to Professor Colin Hansen’s submission to the second Federal Senate inquiry in Australia. We encourage you to view details of the relevant Senate inquiry and read submission 26.
Other NASA research showed that wind turbine generated infrasound was being measured in 1985 from downwind wind turbines.
Early European acoustics research
Research by Pedersen and Waye, published in 2004, clearly shows how wind turbine noise is uniquely and highly ‘annoying’ compared to rail, road and aircraft noise, which at the time was attributed primarily to the visual effect of the turbines and lack of economic benefits from being a turbine host.
Many acousticians and medical practitioners working in this area now believe that the obvious difference in ‘annoyance’ between these noise sources is due to the presence of low frequency noise. Wind turbine hosts who benefit financially are also reporting symptoms and people are consistently reporting effects when they cannot see the wind turbines, and the symptoms are occurring at times when low frequency noise is being measured.
The recent Arra & Lynn literature review from Ontario has a list of the relevant peer reviewed published papers they examined which include much of the early work from Europe (specifically the Netherlands and Sweden).
Dr Frits Van Den Berg (2006) examined wind turbine noise in his doctoral thesis and has worked in this area since. He noted that most of the sound energy present was down in the lower frequencies, including infrasound from horizontal axis wind turbines. At the time this sound energy was not thought by him and others to be important, because it was below the then accepted “thresholds of audible perception“.
Thresholds of perception vs audible perception
Since this time, the work of Professor Alec Salt and others including Dr Malcolm Swinbanks has raised the issue of the accuracy of the original “threshold of audible perception” data, because physiological effects such as elevated blood pressure, tachycardia and symptoms of nausea, headaches and feeling “fretful and tired” have been reported in peer reviewed published research at levels well below these thresholds of audible perception. A more accurate marker is therefore individual thresholds of perception (which are not necessarily audible).
It is important to note that the useful work done in Europe almost 10 years ago was done with much smaller wind turbines. As the next piece of the ‘puzzle’ shows below with Moller & Pedersen’s research – “SIZE MATTERS”.
Danish research shows increased LFN & annoyance as size increases
Professor Moller and Professor Pedersen have shown that as turbine size and power generation capacity increase, so does the proportion of low frequency noise emitted and thus the consequent increased reported ‘annoyance’ to neighbours. This is thought to be responsible for at least some of the symptoms some people are experiencing, in greater severity and over greater distances with the larger wind turbines particularly.
Origin of the 10km setback, & supportive evidence
The Waubra Foundation field evidence which informed our Explicit Cautionary Notice (ECN) choice of 10km distance resulted from credible and consistent reports of symptoms such as the characteristic sleep disturbance of waking suddenly in an anxious, frightened, panicked state, tinnitus and body vibrations which clearly correlated with wind turbine operation, and were occurring out to 10km from the nearest wind turbine. Since the ECN was issued reports of people being affected at distances of out to 30km and more have also been reported. These individuals describe a typical history of increasing sensitisation to ILFN.
Effects on sleep out to these distances 5km from the nearest wind turbine and beyond has been confirmed by three independent population surveys (Wang, Morris and Schneider) done in Australia at Waterloo wind development in South Australia (3MW V 90 VESTAS) and at Cullerin Range in New South Wales (2MW REPOWER). These population surveys revealed much greater proportions of the population were adversely affected by the wind turbine noise with respect to their sleep (eg Wang’s survey at Waterloo found that 50% of households out to 5km who responded were characterised as moderately to severely affected by the noise).
Acousticians Professor Colin Hansen and Mr Steven Cooper have measured infrasound and low frequency noise from wind turbines 8 – 10km from the homes of these residents at Waterloo. The wind turbines are not visible to those residents, but clearly audible under certain wind and weather conditions. These residents have reported the characteristic pattern of sleep disturbance, worsening tinnitus and body vibrations at the time they can perceive and sometimes hear the wind turbines.
Distances of adverse impact for other noise sources
Dr Steve Robinson found that residents in the Hunter region impacted by mining noise were affected out to 10km by the night time noise.
More recently Dr Geralyn McCarron’s field surveys at Tara CSG fields reported residents living out to 15km from the nearest field compressors were troubled by the night time low frequency noise emissions (p26).
American research & field studies
Noise Engineers in the USA have been expressing concerns about what they were seeing since 2007. Rick James and George Kamperman were two who realised there was a serious problem early, and did what they could to investigate and expose the problems.
More recently, Rick James and Wade Bray, have used Sound Quality analysis software to show that the turbines cause rapid changes in air pressure which routine acoustic instruments will not detect. They hypothesise that this change is contributing to the symptoms people are experiencing at sound pressure levels previously thought to be safe.
Rob Rand and Stephen Ambrose conducted an acoustic field survey in Falmouth, USA and reported on it in December 2011. They described the house as acting like an “acoustic drum”. They also found the proportions of sound energy inside the home was remarkably different to that outside, and that the proportions of ILFN inside the home were much greater than expected, and markedly different to outside the well insulated home. Unexpectedly both these acousticians developed the characteristic symptoms, and both took from days to weeks to recover. Both had conducted acoustic surveys at numerous wind developments previously, and did not experience those symptoms on those occasions.
Most recently in December 2012 the cooperative acoustic survey at the Shirley Wind Development, Wisconsin has broken new ground, by having four firms of acousticians present, including those working for the wind developer (Hesslers) and those working for the residents (Rob Rand), as well as two independent observers, Dr Paul Schomer and Mr Bruce Walker. The conclusions of ALL those acousticians in the joint report were as follows:
“The four investigating firms are of the opinion that enough evidence and hypotheses have been given herein to classify LFN and infrasound as a serious issue, possibly affecting the future of the industry. It should be addressed beyond the present practice of showing that wind turbine levels are magnitudes below the threshold of hearing at low frequencies”
Unfortunately, the wind developer refused to cooperate with requests to assist with “on off” testing, which would have helped definitively prove the measured impulses in fact came from the wind turbines and were causing the reported symptoms.
Australian research & field studies
Mr Steven Cooper has been measuring the full spectrum of acoustic emissions inside and outside homes for over a year. Cooper has used the “narrow band analysis” to better understand the precise exposures people are living with. He has measured the characteristic acoustic signature downwind, upwind and crosswind from the turbines, and has measured the same acoustic signature 8km away from the nearest wind turbine at Waterloo. The resident in that home has had poor sleep from repetitive sleep disruption since the turbines were erected.
Mr Les Huson has also conducted acoustic surveys at the homes of sick people, and is in the process of analysing that data.
Professor Con Doolan from Adelaide University, Australia, has shown in one case study from Waterloo wind development there is a dose response relationship and direct correlation between specific episodes of annoyance and low frequency noise. Unfortunately because of the lack of cooperation by the wind developer it was not possible to conduct the ‘on off ‘ testing which would have confirmed what that resident said – that the audible low frequency noise on those ‘annoyance’ episodes was coming from the wind turbines (VESTAS V9o) , the closest of which was 2.5km from their home.
Dr Bob Thorne, psychoacoustician, has conducted a seven year research program investigating wind turbine noise. Most recently, he conducted a small independent case series study (with a couple of controls for comparison) utilising subjects who live or lived near two Victorian wind developments, and collecting both acoustic and health data. Dr Thorne’s results are extremely concerning. For the first time, his data has captured what the residents and some of the clinicians are saying with respect to the severity of their illnesses and the severity of the sleep deprivation.
Dr Thorne found that both sleep deprivation, impaired sleep quality and mental health problems were common amongst this study population. Dr Thorne also found that comparing his data with previously established norms for different population groups, that the health of his study subjects was worse even than hospital in-patients, widely acknowledged to be the sickest of any population group.
Additional concerns have been raised about the possibility of Vibroacoustic Disease (VAD) developing with longer term exposure to IFLN and vibration. The initial research has been conducted in Portugal by Professor Mariana Alves-Pereira (biomedical engineer) and Dr Nuno Castelo Branco (pathologist) and their research team. Much of their work was informed by the pathologies being observed in a population of aviation workers in an ILFN rich environment, but expanded to include residents living near ILFN rich environments such as industrial facilities which included wind developments.
From their work, there is emerging clinical and research evidence of various pathological processes including characteristic thickening of collagen, in tissues such as pericardium (the connective tissue around the heart), and cardiac valves. Recent peer reviewed published research from Taiwan has confirmed this pathology in Taiwanese aviation workers with a dose response effect, and there are clinical reports coming from residents and their clinicians in Europe, and a very concerning case of a child in Portugal who was exposed in utero and in early childhood to an ILFN rich environment, and subsequently developed the characteristic cardiac valve pathology.
Further research must be undertaken
This is an evolving field of science, requiring further multidisciplinary research to determine the exact causative mechanisms of the sleep disturbance, physiological stress, and vestibular dysfunction symptoms being reported.
There is no doubt, however, that serious harm is being done to neighbouring rural residents all over the world from low frequency acoustic pollution from wind turbines and other sources – and that this increases over time, in both severity and the numbers of people affected.
To see the research priorities identified by the Waubra Foundation, please visit the Research Questions page.