Medical Officer of Health
REPORT TO THE BOARD
Wind Turbines and Sound/Noise
Review of Noise Impact Assessment Report Waubra Wind Farm ¹
There is extensive world-wide debate between acousticians, health professionals and the affected communities regarding potential adverse health effects due to the influence of wind farms.
Regulatory authorities who hear applications for wind farm planning are receiving an increased number of peer-reviewed acoustical and health impact related reports and professional evidence.
Many reports, from credible institutions such as the World Health Organization (WHO) and universities around the world, demonstrate that sound influences both psychological processes and physiological systems. Sound can affect the way we think and behave as well as cardiovascular, gastrointestinal and hormonal activities. Sound can produce a calming or distressing effect on an individual, depending on the nature of the sound and the person hearing it.
There is convincing evidence in the literature to conclude that, in some people, noise can induce annoyance and disrupted sleep including difficulty falling asleep and sleep interruption. Inadequate and disrupted sleep is associated with fatigue, cognitive impairment, increased risk of obesity, impaired glucose tolerance, high blood pressure, cancer, depression and impaired immunity.
This disruption from wind turbine noise is poorly predicted by simple measurements of the physical properties of the noise. As this disturbance can compromise health in susceptible individuals, care must be taken with respect to host communities in the siting of wind turbine installations.
Low Frequency Sound and Infrasound ²
Many animals including mammals can sense low amplitude, low frequency sound and infrasound. In nature, “infrasound” corresponds to potentially dangerous situations such as earthquakes, landslides, trees falling, predators approaching, etc. All animals studied respond to such sound by becoming more alert. This is a survival mechanism and prepares the animal for “fight or flight”. Blood is diverted from the digestive system to the muscles, adrenaline is released, cortisol levels rise which add to the state of arousal and fear. Sleep initiation is delayed and the pattern of sleep is disrupted.
Human hearing perception, mediated by the inner hair cells of the cochlea, is insensitive to infrasound. Other sensory cells or structures in the inner ear are more sensitive to infrasound and can be stimulated by low frequency sounds at levels below those that are heard. The concept that an infrasonic sound that cannot be heard can have no influence on the inner ear physiology is incorrect. Some clinical ear disease conditions may cause the individual to become more sensitive to infrasound.
It is hypothesized that since some people are more sensitive to low frequency sound than others, these people would be most affected by prolonged exposure to low frequency, low amplitude sound waves such as those generated by a wind farm.
Wind Turbine Syndrome ³
Dr. Nina Pierpont (Wind Turbine Syndrome) has completed a small epidemiological survey with 38 people who moved away from their homes because of distress after being exposed to wind turbine development. These people were from Canada, UK, Ireland, Italy and USA. The most common baseline, pre-exposure complaint from this small sample was motion sensitivity (53%). Migraine headaches and pre-existing hearing impairment such as tinnitus, deafness and previous noise exposure were also present in about 24% of subjects. Mental health disorders and serious medical illness was present in 21%. (see Table)A symposium regarding these topics is planned for late October in Picton ON.
First International Symposium
The Global Wind Industry and Adverse Health Effects: Loss of Social Justice?
October 29 – 31, 2010
Program and registration information are attached for your reference.
¹ – Report No 1537 Noise Measurement Services Pty Ltd. July 2010, Rev. 1, Noise Impact Assessment Report, Waubra Wind Farm
² – Salt, A.N., Hullar, T.E., Responses of the ear to low frequency sounds, infrasound and wind turbines, Hearing Research (2010), doi: 10.1016/j.hears.2010.06.007
³ – Pierpont, Nina, M.D., PhD., 2009, Wind Turbine Syndrome, A Report on a Natural Experiment