Apart from such diverting facets, in the ’90s, the discovery that wind turbines emit weak levels of infrasound soon stirred up protests. The growing list of symptoms reportedly caused by infrasound arguably culminated in the 2009 publication Wind Turbine Syndrome: A Report On a Natural Experiment, by Nina Pierpont. Her list includes: panic, sleep disturbance, headache, tinnitus, dizziness, nausea, and visual blurring. This list has since become central to a growing anti-wind community, but has not been recognized by any formal international classification. Today there are more than 2,200 anti-wind groups globally.
Yet infrasound from wind turbines is no different than infrasound caused by other harmless, common sources. “Everyone is surrounded by infrasound every day. It’s emitted by natural sources like the surf, storms, wind itself, our own heartbeat and respiration. We also are exposed to it in cars, from ceiling fans, motors, and urban noise,” says Simon Chapman, a professor emeritus at the University of Sydney. “If wind turbines were harmful to nearby residents, entire cities and small nations would be stricken across much of Europe, where we see the highest density. Copenhagen is surrounded by turbines but my Danish colleagues are not seeing queues of sick people.”
I emailed Pierpont to ask about her position, in light of the scientific evidence against it. She offered a new take on how wind turbines cause harm, seemingly different from the attribution to infrasound heavily implied in her book: “Wind turbines produce rhythmic, repeated air-pressure pulses that noise analyzers characterize as infrasound … but it isn’t,” she wrote. Her current belief is that the the negative effects are caused by “repetitive stimulus the body is interpreting as seasickness.”
She elaborated: “I called this simply ‘infrasound’ in my 2009 book because the specific qualities of the wind turbine infrasound/low frequency ‘acoustic emissions’ had not at that point been defined. My calling it ‘infrasound’ got me into hot water with certain acousticians, though I was attempting to sidestep the issue of exactly what the acoustic emission was and focus on the associated symptoms.”
What is certain is that prolonged exposure to unwanted noise at any level can be a source of great stress, and thus be very harmful despite a lack of any direct physical symptom. If people who live near turbines are continually told about wind-turbine syndrome, harmless infrasound can easily become very problematic. Geoff Levanthall, a senior U.K. acoustician, provided me with an example: “The proportion of sleep disturbance, which people attribute to wind turbines, is not very different from the proportion of sleep disturbance reported in general—about 30 percent. So a lot of people wake up during the night, and if they happen to live near a turbine, they say it was the turbine that woke them up.”