Being exposed to noise from wind turbines is only scientifically linked to one adverse health effect: chronic annoyance, a survey of research evidence shows.

A report released today by an expert panel of scientists found "sufficient evidence" that exposure to swishing, thumping and other noises from wind turbines "can contribute to annoyance."

If there were effects that were intense or prevalent, we would likely be seeing more evidence for them. - Tee Guidotti, researcher

But scientific evidence of other effects that some people have blamed on wind turbine noise – including stress, fatigue, nausea, dizziness, ringing in the ears, cardiovascular disease and diabetes – was "inadequate" to draw any conclusions about whether they are really linked to wind turbines, said the report titled Understanding the Evidence: Wind Turbine Noise, published today by the Council of Canadian Academies.

The scientific literature, "is not complete or extensive enough to address all conceivable issues," said panel chair Tee L. Guidotti in a statement. "However, it can give us a hint as to what may be there: annoyance and possibly sleep disturbance, though the evidence is limited.

"Just as important, it can give us a hint as to what is probably not there. I would note that if there were effects that were intense or prevalent, we would likely be seeing more evidence for them."

Guidotti is a physician and public health expert who is currently Fulbright Visiting Chair at the Institute for Science, Society and Policy at the University of Ottawa.

According to the Canadian Wind Energy Association, at the end of 2014 there were enough wind turbines installed across Canada to potentially generate 9,694 megawatts of electricity – enough to power over two million homes.

Controversy over wind farms

But the installation of many wind projects has been controversial in their communities. Opponents have blamed the noise from wind turbines for a variety of health problems. In 2011, a family in Thamesville, Ont., launched a $1.5-million lawsuit against Suncor Energy, alleging nearby wind turbines were causing health problems including headaches, stress, sleep disturbances, ringing in the ears and depression.

In 2012, in response to public concerns about possible health effects from wind turbines, Health Canada asked the Council of Canadian Academies to look into whether evidence exists to link exposure to wind turbine noise with adverse health effects.

The council is an independent, non-profit organization that provides evidence-based expert reports to federal government departments upon request, to help inform public policy.

Health Canada also conducted its own study and reported in 2014 that it found no link between wind turbine noise and health effects, including dizziness, chronic illnesses, stress or sleep disturbances.

The Council of Canadian Academies' 10-member expert panel identified more than 30 symptoms and health effects that have been blamed on wind turbine noise in research literature, on the web and in legal decisions. Its members pored through reports on studies in scientific journals, at conferences and in other documents, and analyzed 41 that were relevant.

Turbines don't cause hearing loss

In addition to the link between wind turbine noise and annoyance, the report found:

A relationship between wind turbine noise and sleep disturbances also "might exist."

Wind turbine noise does not cause hearing loss.

The report's inability to link wind turbine noise with health effects was "mainly as a result of lack of evidence or problems with the quality of the evidence," the panel wrote.

Christian Giguère, a professor of audiology and speech-language pathology who was a member of the panel, said that's largely because wind turbines are a relatively new source of noise and not that many studies have been done yet.

Some of the gaps have been filled by a new Health Canada study, he added, but that could not be included in the expert panel's analysis, as it was released too late.

The panel made note of a number of gaps that still need to be addressed, such as the effects of wind turbines on vulnerable populations, such as infants, children, and people with inner ear problems. For example, Giguère said, it's not known whether wind turbines could cause annoyance or affect cognitive development in children.