Preventative medical limits for chronic traffic noise exposure

Abstract

Because of an expert’s report on the medical effects of noise on healthy adults, permissible values for mainly traffic noise have been estimated by the standard of knowledge. If the permissible values are exceeded, then preventative medical action is necessary. Below this value the probability of noise-induced health hazards is essentially zero. The effect due to noise as a health hazard is, besides the mechanical damage of the inner ear, a psycho-physiological deregulation which can be either indirectly due to the annoyance or directly caused by stress of the vegatative-hormonal system. Therefore, different permissible values for annoyance, the stress on the vegetative-hormonal system, and for the loss of hearing are suggested, for both continuous and maximum noise levels. In addition, the deregulation depends on the time of the acoustic exposure because the sensitivity to noise follows a 24-h cycle (circadian rhythm). It is therefore necessary to give personal permissible limits for the evening noise and the nocturnal noise.