Mining the available scientific evidence, a new report from Ontario’s chief medical officer of health finds that while living near wind turbine farms “may annoy some people,” it’s a stretch to blame the turbines for health problems.
“According to the scientific evidence, there isn’t any direct causal link between wind turbine noise and adverse health effects,” Dr. Arlene King said last week on the release of her report.
Though the report does offer some public relations advice for developers planning wind power projects in the future, it also adds the weight of the province’s Health Department against criticisms now levelled against various wind power developments.
Some people living near wind turbines have previously reported symptoms such as “dizziness, headaches and sleep disturbance,” the province said, but King’s report finds no evidence of a direct link to those from the giant spinning blades now dotting a number of rural Canadian horizons.
In Ontario, where over 690 wind turbines now operate, the minimum setback distance for a single turbine is 550 metres, and that increases with the number of turbines at a given site.
For example, a wind project with five turbines, each with a sound power level of 107 decibels (dB), must have its turbines set back at least 950 metres from the nearest receptor. The setback regulations are meant to limit sound at the nearest residence to no more than 40 dB.
According to the World Health Organization (WHO), King wrote, this 40-dB guideline is below the level at which effects on sleep and health occur. The province, in its release May 20, noted 40 dB as “approximately the noise level experienced in a quiet office or library.”
“However,” King wrote in her report, “it is above the level at which complaints may occur.”
In the report, she noted, published papers in peer-reviewed scientific journals, and reviews by recognized health authorities such as the WHO, carry more weight in the assessment of health risks than “case studies and anecdotal reports.”
King notes a “key data gap” that could be dealt with in a future study: specifically, “sound measurements at residential areas around wind turbines and comparisons with sound levels around other rural and urban areas,” to see what the ambient noise levels are like in residential areas across Ontario, not just near wind farms.