Noise & Health Effects of Large Wind Turbines

Several physicians from around the world -- e.g., Amanda Harry in England, Robert McMurtry in Ontario, Robyn Phipps in New Zealand -- have recorded a common set of ill health effects among people living near industrial-scale wind turbines. The symptoms began when local turbines began to turn, and they are relieved when the victims leave the area. Many families have had to abandon their homes as unlivable.

The symptoms include:

Dr. Nina Pierpont of New York has called it "wind turbine syndrome" and determined that its primary cause is the effect of low-frequency wind turbine noise on the organs of the inner ear. Click here for her book and other information on the subject. Dr. Pierpont's work has led her to recommend that large wind turbines not be sited closer than 2 kilometers (1-1/4 miles) from a home -- click here for a petition for 2-km minimum setbacks.

Shadow flicker -- where the sun behind turbine blades creates a strobing effect on the ground -- may also be intrusive and harmful. Many people are also concerned about stray voltage, or ground current, caused by the hundreds of thousands of feet of buried electric cable in a typical wind power facility.

Finally, an increase in noise is itself disruptive and can cause sleep loss and stress, especially in rural areas where there is an expectation of quiet. The World Health Organization notes that "Measurable effects of noise on sleep begin at LAeq levels of about 30 dB. ... When noise is continuous, the equivalent sound pressure level should not exceed 30 dB(A) indoors, if negative effects on sleep are to be avoided. For noise with a large proportion of low-frequency sound [dB(C)] a still lower guideline value is recommended."

Acousticians Rick James and George Kamperman have extensively studied wind turbine noise: click here to read their siting guidelines. In brief, they recommend a limit at the property line of 35 dBA or 5 dBA above the preconstruction ambient level, whichever is lower, and a limit of 50 dBC or 20 dBC above the preconstruction ambient dBA level, whichever is lower, for low-frequency noise.

Conditions ratified by the U.K. High Court in May 2011 define pulsing "blade swish (or thump)" noise, or "amplitude modulation", such that the turbine noise (measured in 125-millisecond intervals 3.5-35 metres outside a dwelling) can not rise or fall by more than 3 dB within any 2-second period more than five times in any 1-minute period with an average sound level of 28 dBA or more, six or more times in any hour.

In Ontario, the Society for Wind Vigilance provides information about adverse health effects and wind turbines, including annoyance, stress, sleep disturbance, and physiological effects: click here.

For all of the items about wind turbine noise in the National Wind Watch Resource Documents, click here.

© National Wind Watch, Inc.