Wind energy is increasingly being considered a viable and attractive power source. Many countries, including the U.S., Germany, Spain, China, and India, are putting policies into place to drive the development of their wind energy industries. In Canada, the amount of wind energy being harnessed for use in our homes, offices, and factories has grown quickly over the past few years, led by Ontario with its Green Energy Act.
However, a backlash has been growing in many places where wind power is being developed. In Ontario, one of the main criticisms of wind development has been its impact on human health, mostly because of the noise that wind turbines produce. Yet, the peer-reviewed scientific research indicates that the sound from windmills, which generally falls into three categories (audible sound, low frequency, and infrasound), has little to no impact on human health.
This is especially true if windmills are built far enough away from residences. For example, the required setback in Ontario is 550 metres. At this distance, the audible sound from windmills has been found to be below 40 decibels, which is around the level of sound you'd find in most bedrooms and living rooms. Studies from the University of Massachusetts similarly found that even if the sound were audible, annoyance would be minimal.
Critics have also pointed to low frequency sound and infrasound as the source of health impacts from wind turbines. These are sounds that are either difficult to hear or inaudible to humans. However, Ontario's Chief Medical Officer of Health did a review of the scientific literature and found no evidence that low frequency sound from wind turbines causes adverse health effects.
Research from Sweden and the Netherlands may shed some light on the opposition that windmills are facing, despite the lack of evidence for human health impacts. At or just under 40 decibels, 73 per cent of people could notice the sound and six per cent were annoyed. But those who did not like windmills or found them ugly were more likely to notice the sound and were more likely to be annoyed by it.
Though we should always remain open-minded about new and emerging research on any issue, the evidence seems clear that wind turbines built with appropriate setbacks do not constitute a health hazard. And wind becomes a more attractive energy source when you consider the health impacts of the main energy alternative, burning coal and other fossil fuels.
The Canadian Medical Association estimated that in 2008 Canada's air pollution was responsible for 21,000 premature deaths, 92,000 emergency room visits, and 620,000 visits to a doctor's office. Even if you look only at the health impacts of Ontario coal-fired power plants, the numbers are significant and startling.
When considering whether Canada needs to curtail the development of its wind resources or expand wind power in the way that Ontario's Green Energy Act proposes, we should heed the conclusion of Maine's Center for Disease Control. After dismissing the notion of a moratorium on wind development due to its health impacts, the Center's Dr. Dora Ann Mills concluded, "If there is any evidence for a moratorium, it is most likely on further use of fossil fuels, given their known and common effects on the health of our population."
As for the impacts on wildlife, that's another story. But most scientific research shows that newer technologies and proper locating can overcome most of the threats to birds and bats. One recent study also noted that "the number of birds killed in wind developments is substantially lower relative to estimated annual bird casualty rates from a variety of other anthropogenic factors including vehicles, buildings and windows, power transmission lines, communication towers, toxic chemicals including pesticides, and feral and domestic cats."
It's never easy to find energy technologies that will satisfy everyone, but with the world facing ever-growing negative consequences of burning fossil fuels, we must weigh our options. In doing so, wind power comes out ahead. If we ensure that care is taken to use technologies with minimal environmental impact and to locate turbines in areas where effects on humans and animals are also minimal, there is no good reason to oppose wind power.
Written with contributions from David Suzuki Foundation climate change policy analyst Dale Marshall.
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