|Fact sheet No 258: Occupational and Community Noise - February 2001 (WHO, 2001, 5 p.)|
The recognition of the noise as a serious health hazard as opposed to a nuisance is a recent development and the health effects of the hazardous noise exposure are now considered to be an increasingly important public health problem.
· Globally, some 120 million people are estimated to have disabling hearing difficulties. (ref. Guidelines p.X)
· More than half citizens of Europe live in noisy surroundings; a third experience levels of noise at night that disturb sleep. (ref. Guidelines p.XII)
· In the USA in 1990 about 30 million people were daily exposed to a daily occupational noise level above 85 dB, compared with more than nine million people in 1981; these people mostly in the production and manufacturing industries. (ref Noise Sources p.85)
· In Germany and other developed countries as many as 4 to 5 million, that is 12-15% of all employed people, are exposed to noise levels of 85 dB or more. In Germany, an acquired noise-related hearing impairment that results in 20% or more reduction in earning ability is compensatable; in 1993, nearly 12 500 new such cases were registered. (ref Noise Sources p.85 and p. 86)
· Prolonged or excessive exposure to noise, whether in the community or at work, can cause permanent medical conditions, such as hypertension and ischaemic heart disease. (ref. Guidelines p.XII)
· Noise can adversely affect performance, for example in reading, attentiveness, problem solving and memory. Deficits in performance can lead to accidents. (ref. Guidelines p.XII)
· Noise above 80 dB may increase aggressive behaviour. (ref. Guidelines p.XIII)
· A link between community noise and mental health problems is suggested by the demand for tranquillizers and sleeping pills, the incidence of psychiatric symptoms and the number of admissions to mental hospitals. (ref. Guidelines p.XII)
Noise can cause hearing impairment, interfere with communication, disturb sleep, cause cardiovascular and psycho-physiological effects, reduce performance, and provoke annoyance responses and changes in social behaviour. The main social consequence of hearing impairment is the inability to understand speech in normal conditions, which is considered a severe social handicap.
Whereas in the developed world hearing impairment is mostly restricted to the work setting, in cities in the developing world the problems are worse, with increasing hearing impairment due to community noise.