Opponents of the growing number of wind turbines across Iowa complain sound and flickers from the massive towers are hurting their health, but researchers say there’s little scientific evidence to support those claims.
A paper released Thursday from three Iowa groups looked at research around the public health impact of wind turbines and found little evidence they’re harming neighbors.
Neighbors complain that the sights and sounds of the spinning blades cause headaches, nausea and other health problems. Critics also complain both about the noise from the rotors and low-frequency “infra-sound.”
Controversy around wind turbines has grown as Iowa utilities have rapidly adopted wind energy. Thirty-seven percent of the state’s electricity comes from wind, the largest share in the nation.
Research studies found sound from wind turbines may be annoying, but they “have established no adverse health effects,” said Peter Thorne, a professor and head of the University of Iowa’s Department of Occupational and Environmental Health.
The paper focused on sound, but researchers also found no health impacts from turbine flickers, such as seizures. “That’s not happening,” Thorne said.
He wrote the paper with David Osterberg, founder of the Iowa Policy Project, and Kerri Johannsen, energy program director at the Iowa Environmental Council. Both groups support expanding wind, solar and other forms of renewable energy across the state.
The groups looked most closely at two studies: a 2015 review by the Council of Canadian Academies and a 2014 report from a [researcher at] the Massachusetts Institute of Technology.
The Canadians compiled a list of 32 symptoms and health concerns associated with turbines, with the most common including annoyance, sleep disturbance and stress-related conditions.
“Wind turbines produce sound pressure, but if the frequency is at or below the threshold of human perception and the sound pressure level is low at area residences, there is little or no exposure to cause human health problems,” the Iowa report says.
With the studies finding no link between health outcomes and wind turbines, researchers dug into how people’s feelings about turbines affected their symptoms.
“When people tell you they’re experiencing some sort of symptoms – that they have compromised health and there’s not enough evidence beyond annoyance – you have to look at what else there might be” going on, Osterberg said.
Researchers found that test subjects who looked at “provocative videos” about turbines got more “more symptoms,” Osterberg said.
The two studies found that “beliefs and what people are told about the risks and benefits of wind turbines have a major impact on reported health” effects, whether or not they were actually exposed to turbine-like sound pressure, the Iowa groups reported.
They called it “nocebos” – “a detrimental effect on health produced by psychological or psychosomatic factors such as negative expectations of treatment or prognosis.”
“It relates to the cause of the symptoms they experience,” Thorne said. “We’re not denying somebody the claim of symptoms associated with the wind.”
“Moving a turbine further away probably isn’t going to do any good. That’s probably not what’s having the effect” on people’s health, Osterberg said.
“There may be non-health policies that help,” he said.
The research indicates that counties need strong policies around where turbines should be located, Johannsen said, giving neighbors greater voice in the decisions.
She said the Iowa Environmental Council initiated the health review to determine if wind energy could be introducing problems across the state.
A member of the Coalition for Rural Property Rights didn’t immediately respond to a request for comment Thursday.
[*NWW note: The McCunney et al. study was funded by the Canadian Wind Energy Association.]