Simon Chapman, University of Sydney
During the Abbott government, the often recalcitrant Senate cross bench was thrown a big, juicy bone plainly intended to sweeten their disposition toward government bills which needed their support to pass. The anti- wind farm Senators were outraged with the National Health and Medical Research Council’s (NHMRC) 2015 report on wind farms which found no strong evidence of health effects from turbine exposure. There have been 25 reviews with similar findings published since 2003. The government may have promised these Senators the gift of the office of the National Wind Farm Commissioner which by February 2015 had received just 42 complaints about 12 wind farms, seven of which have not even been built.
In August 2015, the Senate Select Committee on Wind Turbines published its report. The Committee was chaired by Senator John Madigan, an open opponent of wind farms, and consisted of eight members. Six of these had form in savagely criticising wind farms. The content of their final report was therefore utterly predictable, with Labor’s Senator Anne Urquhart’s minority dissenting report shining like a beacon of respect for evidence.
There was no greater display of the naked demonising agenda of the Madigan-aligned group’s anti wind farm show trial than the total absence in their report of any mention of the world’s largest and most important study of the question of whether living near wind farms was harmful to health.
Health Canada’s Wind Turbine Noise and Health study published its preliminary findings on October 30, 2014. Senator Urquhart’s minority report noted that many submissions to the inquiry recognised the great contribution of the Health Canada “Wind Turbine Noise and Health Study” to the body of knowledge on the potential impacts of wind farms on human health. But the 181-page report made no mention of the study.
The study data were collected between May and September 2013 from adults aged 18 to 79 (606 males, 632 females), randomly selected from each household. They lived between 0.25 and 11.22km from wind turbines in two Canadian provinces, Ontario and Prince Edward Island.
In March, the Health Canada study group published its full findings in a series of open-access papers in the Journal of the Acoustical Society of America, the world’s most cited acoustical research journal, and in Sleep, a leading journal in sleep research. Here is a summary of some of its chief findings.
Do wind turbines increase the prevalence of health problems and sleep disturbance?
The researchers assessed self-reported sleep quality over the past 30 days using the Pittsburgh Sleep Quality Index and a wrist monitor to record the total sleep time, and the rate of awakening bouts and how long these last, for a total of 3,772 nights.
Averaged over a year, the measured sound of the turbines reached a maximum of 46 dB(A) with an average of 35.6. Forty six decibels is around the sound of a dishwasher operating in a kitchen.
Since January 2012, I have collected and catalogued a remarkable 247 different symptoms and diseases wind farm opponents claim are caused or exacerbated by wind turbines in humans and animals.
But the Health Canada study found that:
Self-reported health effects (e.g., migraines, tinnitus, dizziness, etc.), sleep disturbance, sleep disorders, quality of life, and perceived stress were not related to wind turbine noise levels.
Both self-reported and objectively measured sleep outcomes consistently revealed no apparent pattern or statistically significant relationship to wind turbine noise levels.
But, unsurprisingly, sleep was affected by whether residents had other health conditions (including sleep disorders), their caffeine consumption, and whether they were personally annoyed by blinking lights on the wind turbines.
Sleeping problems affect around 29% of all communities, regardless of whether they are near wind farms or not.
Do wind turbines cause measurable stress?
The researchers used a recognised scale to measure self-reported stress (the perceived stress scale – PSS) as well as recording hair cortisol concentrations, resting blood pressure, and heart rate.
However, the majority (77%–89%) of the variance in the perceived stress scale (PSS) scores was unaccounted for by differences in these objective measures. And wind turbine noise exposure had no apparent influence on any of them.
Again, the study concluded that the findings did not support an association between exposure to wind turbines and elevated self-reported or objectively defined measures of stress.
Do wind turbines annoy people?
Expressions such as being “hot and bothered” are well understood. When people are annoyed by something in their life, this can lead to the onset of symptoms. Being annoyed is not health problem in itself, but chronic annoyance can have health consequences.
The Health Canada study reported:
Visual and auditory perception of wind turbines as reported by respondents increased significantly with increasing wind turbine noise levels as did high annoyance toward several wind turbine features, including the following: noise, blinking lights, shadow flicker, visual impacts, and vibrations … Beyond annoyance, results do not support an association between exposure to wind turbine noise up to 46 dBA and the evaluated health-related endpoints.
The prevalence of residents reporting that they were very or extremely annoyed by wind turbine noise increased from 2.1% to 13.7% when sound pressure levels were below 30 dB compared to when the noise was between 40–46 dB.
So in summary, those who found the turbines annoying, tended to be those who lived nearer to them.
What factors predict who gets annoyed?
Even for the most annoying features, more than 86% of residents were not very or extremely annoyed by them.
There is much variation among our families, friends working environments in the way people react to noise. A 2014 review of symptoms related to modern technology (including wind turbines) found those who were more anxious, worried, concerned, or annoyed by a source that they believed to be a health risk more commonly reported symptoms than those without such beliefs.
In this Health Canada study, while proximity to the turbines was statistically significantly associated with annoyance, the relationship was weak. It was better explained by factors such as holding negative views about the visual impact of the turbines (not liking the look of them), being able to the see aircraft warning blinking lights, the perception of vibrations when the turbines were turning and high concern about physical safety. These are all perceptual variables that bothered some but not most.
Less than 10% of the participants derived personal benefit from the turbines (such as income from hosting the turbines). Deriving personal benefit had a statistically significant, although modest relationship to not being annoyed. The authors concluded:
these findings would support initiatives that facilitate direct or indirect personal benefit among participants living within a community in close proximity to wind power projects.
This suggests that strategies such as community sharing of rental incomes, offers of free electricity or home improvement and amenity payments may reduce annoyance.
If a Labor government is elected in July, the future of the ill-conceived Office of the National Wind Farm Commissioner is likely to be vulnerable, as it may well be with the expected departure of several wind farm-obsessed cross bench senators in the double dissolution, should the Coalition be returned.
State governments are increasingly removing wind farm planning barriers and the availability now of the Health Canada health report should drive another large stake through the forces determined to slow the growth of wind energy in Australia.
Simon Chapman, Emeritus Professor in Public Health, University of Sydney
This article was originally published on The Conversation. Read the original article.