Written by Alun Evans Professor Emeritus Belfast University
According to the World Health Organisation’s recent report, ‘Night Noise Guidelines for Europe’ , environmental noise is emerging as one of the major public health concerns of the twenty-first century. It observes that, “Many people have to adapt their lives to cope with the noise at night,” and the young and the old are particularly vulnerable.
This is because hearing in young people is more acute and, in older people, a loss of hearing of higher sound frequencies renders them more susceptible to the effects of low frequency noise. It is a particularly troublesome feature of the noise generated by wind turbines due to its impulsive, intrusive and incessant nature.
A recent case-control study conducted around two wind farms in New England has shown  that subjects living within 1.4 km of an IWT had worse sleep, were sleepier during the day, and had poorer SF36 Mental Component Scores compared to those living further than 1.4 km away. The study demonstrated a strongly significant association between reported sleep disturbance and ill health in those residing close to industrial wind turbines.
The major adverse health effects caused seem to be due to sleep disturbance and deprivation with the main culprits identified as loud noise in the auditory range, and low frequency noise, particularly infrasound. This is inaudible in the conventional sense, and is propagated over large distances and penetrates the fabric of dwellings, where it may be amplified. It is a particular problem at night, in the quiet rural settings most favoured for wind farms, because infrasound persists long after the higher frequencies have been dissipated.
Sleep is a physiological necessity and the sleep-deprived are vulnerable to a variety of health problems [2,3]. particularly Cardiovascular Disease in which nocturnal noise is an important factor . Sleep deprivation in children is associated with increased bodyweight [3,5], which is known to ‘track’ into later life, and predisposes to adult disease.
That is why “Encouraging more sleep” is a sensible target in the Public health Agency’s current campaign to prevent obesity in children. It also causes memory impairment because memories are normally reinforced in the later, Rapid Eye Movement, phase of sleep; again, it is the young and the old who are most affected. Sleep deprivation is associated with an increased likelihood of developing a range of chronic diseases including Type II Diabetes, cancer (eg breast with shift work ), Coronary Heart Disease [7,8] and Heart Failure .
Although the quality of the data are mixed, those on Heart Failure reported recently from the HUNT Study  are quite robust as they are based on 54,279 Norwegians free of disease at baseline (men and women aged 20-89 years). A total of 1412 cases of Heart Failure developed over a mean follow-up of 11.3 years.
A dose-dependent relationship was observed between the risk of disease and the number of reported insomnia symptoms: i) Difficulty in initiating sleep; ii) Difficulty in maintaining sleep; and, iii) Lack of restorative sleep. The Hazard Ratios were ‘0’ for none of these; ‘0.96’ for one; ‘1.35’ for two; and, ‘4.53’ for three; this achieved significance at the 2% level. This means that such a result could occur once by chance if the study were to be repeated 50 times, Significance is conventionally accepted at the 5% level. Continue reading here….