ELLSWORTH, Maine — A study panel of health and environmental experts commissioned by the state of Massachusetts found insufficient evidence to support claims that noise from commercial wind turbines directly cause health problems or disease.
But the report, which is garnering attention from both advocates for and opponents of grid-scale wind power in Maine, cautioned that not all potential side effects of living near turbines are fully understood.
The Massachusetts Department of Environmental Protection and Department of Public Health commissioned the study panel in response to concerns that noise, vibrations and “shadow flicker” from spinning turbines can cause health problems in some people.
While Maine is New England’s largest producer of wind power, Massachusetts has set an ambitious goal of generating 2,000 megawatts of electricity from wind by 2020. And as in Maine, the move to develop wind farms has sparked debate over whether living or working near a 400-foot-tall turbine can affect a person’s health.
After reviewing scientific literature on the topic, the panel of seven scientists determined that “there is insufficient evidence that noise from wind turbines is directly (i.e., independent from an effect on annoyance or sleep) causing health problems or disease.” The panel included Dr. Dora Anne Mills, the former head of the Maine Centers for Disease Control and Prevention.
“There is no evidence for a set of health effects from exposure to wind turbines that could
be characterized as a ‘Wind Turbine Syndrome,’” the authors added, using a phrase used by critics of the wind power industry around the world.
The available scientific literature, however, was less clear or too incomplete on other potential impacts, the panel wrote in the January 2012 report.
For instance, the authors noted that while available science shows that “infrasound” — low-frequency pressure waves created by the massive blades spinning through the air — does not impact the vestibular system that contributes to balance and spatial orientation, the effects of infrasound on the inner ear are not fully understood.
The report also acknowledged that there is some evidence to suggest noise from wind turbines can affect sleeping patterns — a complaint made by some Maine residents living near wind farms in Mars Hill and Vinalhaven.
“In other words, it is possible that noise from some wind turbines can cause sleep disruption,” the report stated. “Whether annoyance from wind turbines leads to sleep issues or stress has not been sufficiently quantified. While not based on evidence of wind turbines, there is evidence that sleep disruption can adversely affect mood, cognitive functioning, and overall sense of health and well-being.”
The report stated that “limited scientific evidence” exists suggesting that so-called “shadow flicker” created by sunlight reflecting off of or being blocked by the spinning blades can cause annoyance as well as cognitive or other health effects after prolonged exposure.
The authors also urged Massachusetts regulators to adopt statewide setback standards and decibel levels while recommending that wind power developers minimize the “annoyance” factor by engaging the public in the process.
Not surprisingly, people on both sides of the debate over commercial wind power in Maine seized on parts of the report to support their arguments.
“For us, this is further confirmation that the questions about health impacts from wind power in Maine have been answered time and time again,” said Jeremy Payne, executive director of the Maine Renewable Energy Association, an industry trade group. “We are hoping that the folks concerned about this [issue] will acknowledge that there are no known impacts.”
The report’s authors acknowledged repeatedly that turbines can cause “annoyance” in neighbors. But Payne said he doesn’t believe the wind power industry — or many others, for that matter — will ever be able to eliminate the potential to annoy or irritate some people. He said the industry has changed practices to address concerns, however.
“I think the industry will continue to adapt and make changes if and when there is scientific and medical research to dictate that,” Payne said.
The industry’s critics see things differently.
Dr. Monique Aniel, a retired radiologist who is co-chair of the Citizen Task Force on Wind Power, pointed to the report’s careful wording on the possibility of turbine noise disrupting sleep.
“In other words, many people in this country and worldwide testified that wind turbine noise disturbs their sleep, but they have not been the subject of large controlled studies, so their testimony is ignored,” Aniel said.
Chris O’Neil, who represents the organization Friends of Maine’s Mountains at legislative hearings and during proceedings with regulators, wrote in an email that while “sleep disturbance may or may not be a direct cause of disease … it certainly does not enhance one’s health and well being.”
O’Neil also pointed out that the Maine Board of Environmental Protection, after holding lengthy hearings on the issue of turbine noise, voted last year to lower the maximum noise levels at nearby houses during evening hours to 42 decibels. That was still higher than O’Neil and other critics wanted, but he said it shows the board recognized turbine noise can impact neighbors.
Both O’Neil and Aniel also criticized Dr. Dora Anne Mills’ service on the panel because she has said publicly that she has seen no scientific evidence of adverse health effects from turbine noise apart from annoyance. Mills is now vice president for clinical affairs at the College of New England.