A new study by American health and engineering experts has found no evidence that wind turbines can directly cause a set of physical and psychological symptoms dubbed “wind turbine syndrome” by some wind farm critics.

The state of Massachusetts last week published the Wind Turbine Health Impact Study, in a bid to address questions local residents may have about the health implications of wind farms at a time when the state is preparing to ramp up its wind power capacity from 40MW currently to 2GW by 2020.

The panel of health and engineering experts that carried out the review found people living near turbines may become annoyed by noise, vibrations, or shadow flickering, but concluded there was no evidence that psychological distress or mental health problems were caused by proximity to turbines.

Significantly, the panel dismissed a controversial book by Nina Pierpont, which has claimed infrasonic to ultrasonic noise and vibrations emitted by wind turbines caused a series of symptoms, including abnormal heart beats, sleep disturbance, headaches, tinnitus, nausea, visual blurring, panic attacks, and general irritability.

The experts argued Pierpont’s method of documenting case studies was not rigorous enough to draw any real conclusions, adding that no other study had so far revealed a link between noise from wind turbines and physical symptoms.

“Limitations to the design employed make it impossible for this work to contribute any evidence to the question of whether there is a causal association between wind turbine exposure and health effects,” it said.

“Given this, the very term “Wind Turbine Syndrome” is misleading as it implies a causal role for wind turbines in the described health symptoms.”

The panel also said there was no evidence to back up claims that infrasound directly impacts the inner ear system, which helps people to retain their balance, or that shadow flicker from rotating turbines could cause seizures.

However, the study did acknowledge wind turbines can cause sleep disruption, if the machine installed is particularly loud or very close by.

Interestingly, one Dutch study cited in the report found that people who made financial gains from turbines reported virtually no annoyance, despite noticing the noise just as much as those who did not benefit economically and reported much higher levels of annoyance.

The researchers said the results suggested that people’s attitudes towards turbines could help determine the level of annoyance caused. However, they added that people who benefit economically could switch off the turbines when they became annoying.

“This is a complex issue that the panel spent many months studying. We took our work very seriously,” said panel member Wendy Heiger-Bernays, PhD, a professor of environmental health who worked on the study.

“By reviewing the available data and information, we believe that we have significantly added to the understanding of the potential for health effects from wind turbines.”

Robert Norris, head of communications at trade association RenewableUK, told BusinessGreen that it has always maintained there was no evidence to show Wind Turbine Syndrome existed.

“We welcome the thorough research undertaken by the Massachusetts Department of Environmental Protection, as it exposes some of the unscientific myths which have been pedalled by small but vociferous anti-wind campaign groups,” he said.

“The fact is that harnessing the power of wind is one of the safest, cleanest ways to generate electricity. It forms a significant part of this country’s plans to reduce our dependence on expensive and polluting fossil fuels, so that we can utilise an abundant, natural low carbon resource instead. That change will have hugely beneficial effects on everyone’s health.