Pollution, Noise
Noise pollution is undesired sound that is disruptive or dangerous and can cause harm to life, nature, and property. It is often said that noise differs from other forms of pollution in that, unlike atmospheric pollutants for example, once abated, noise leaves no residual accumulation in the environment or the human body. Noise does leave behind its effects, however, and these can deteriorate after continued exposure to harmful sounds. So it is not true, strictly speaking, that “noise … leaves no visible evidence” (Lai 1996, p. 389).
The hazardous effects of noise depend on its intensity (loudness in decibels), duration, and frequency (high or low). High and low pitch is more damaging than middle frequencies, and white noise covering the entire frequency spectrum is less harmful than noise of a specific pitch. Noise may be ambient (constantly present in the background) or peak (shorter, louder sounds).
Noise-induced hearing loss (NIHL) in humans is the major, though by no means only, problem stemming from noise pollution. In 1978 the U.S. Environmental Protection Agency (EPA) Office of Noise Abatement and Control estimated that around twenty million Americans were exposed daily to noise resulting in permanent hearing loss (EPA 1978). In 1990 about thirty million people in the United States were exposed daily to occupational noise levels above 85 decibels, compared with just over 9 million people in 1981. Exposure for more than 8 hours a day to sound in excess of 85 decibels is potentially hazardous. In Germany and other developed countries, as many as four to five million people, that is, 12 to 15 percent of all employed people, are exposed to noise levels of 85 decibels or more (World Health Organization 2001).
Loud, abrupt sounds can harm the eardrum, while sustained sounds at lower volume can damage the middle ear; both types of sounds can cause psychological damage. Noise disrupts sleep and communication, and numerous studies have documented the heart-related, respiratory, neurological, and other physiological effects of noise. Stress, high blood pressure, anger and frustration, lower resistance to disease and infection, circulatory problems, ulcers, asthma, colitis, headaches, gastrointestinal disorders, and many other physiological and psychological problems have been linked directly to noise. In addition, children have been shown to suffer from slower language development and disruption of learning as a result of noise. More than five million children in the United States, ages six to nineteen, suffer from noise-induced hearing impairment (Havas 2006). In the United Kingdom, Netherlands, and Spain, exposure to noise impaired children’s reading comprehension and caused a delay in reading skills development (Clark and Stansfeld 2005). In Austria, children in noisier neighborhoods were shown to suffer from increased stress and diminished motivation (Evans et al. 2001). A fetus exposed to noise may experience a change in heart rate, or it may suffer the impact of its mother’s noise-related stress.
In addition, noise can harm animals and the environment, as well as physical property. Livestock and pets are harmed by noise, as are animals in the wild. Noise can also disturb wildlife feeding and breeding. Noise-related property damage includes structural damage from vibrations induced by sound waves and economic harm in the form of lower property values. The true social costs of noise pollution also must include monetary losses from sickness, absenteeism, loss of productivity and earning capacity, and much more.
Noise pollution is not new, but it has become more problematic with the developments associated with industrialization and urbanization. Between 1987 and 1997, community noise levels in the United States were estimated to have increased by 11 percent and were predicted to continue increasing at that rate or more (Staples 1997). Commercial and industrial activities, construction, aircraft, vehicular traffic (highway and off-road), and the rapid increase in the use of machines and other technologies are all associated with noise pollution. Modern household appliances and lawn and gardening equipment are increasingly common sources of noise. Like many other forms of pollution, noise appears to disproportionately affect poor and disadvantaged minority communities, and so is also an environmental justice issue.