““There’s consistent evidence that road traffic noise leads to heart attacks,” says Dr Yutong Samuel Cai, an epidemiologist at Imperial College London. He recently analysed the health data of 356,000 people in Britain and Norway and found that long-term exposure to traffic noise affects our blood biochemistry, over and above the effects of exhaust fumes. “Noise and air pollution usually co-exist, but we can adjust our statistical model to factor out the air pollution. Noise seems to have its own effect on the cardiovascular system.” Another study, from Barts and the London School of Medicine, has linked noise pollution from road traffic to instances of type 2 diabetes. Cai stresses that more study is needed, for example, to quantify the different health impacts of constant low-frequency noise (a motorway) and intermittent peak noise (your neighbour playing techno at 3am). “There’s relatively little study of railway noise or airport noise, for example. But it is a growing area of research at the moment.”
The World Health Organization has calculated that at least 1m healthy life-years are lost every year in western European countries because of environmental noise, with cardiovascular disease contributing to the vast majority of these deaths, especially high blood pressure, heart attacks and coronary heart disease. It is thought that noise triggers the release of the stress hormone cortisol, which damages blood vessels over time. Humans evolved our acute hearing millions of years ago, when we were prey animals and had to pinpoint predators, so it is no wonder we find noise stressful. It is hardwired. A leading acoustics engineer, Trevor Cox, hypothesises that the noises we find most stressful are distress calls – screams with an unhinged roughness to them, caused by the vibrations of the vocal folds when someone is truly terrified. The frequencies are similar to the archetypal horrible sound, fingers scraping down a blackboard; and to an electric drill angrily ripping through plasterboard.
Noise exposure has also been linked with cognitive impairment and behavioural issues in children, as well as the more obvious sleep disturbance and hearing damage. The European Environment Agency blames 10,000 premature deaths, 43,000 hospital admissions and 900,000 cases of hypertension a year in Europe on noise. The most pervasive source is road-traffic noise: 125 million Europeans experience levels greater than 55 decibels – thought to be harmful to health – day, evening and night. However, airport noise and railway noise cause more complaints – ask any of Boris Johnson’s constituents. Hacan, a campaign group for residents living under the Heathrow flight path, claims that 620,000 to 920,000 people are affected by noise from the airport – vastly more than for any other airport in Europe.” …
East Devon Watch 