Noise hazards: the issues, the remedies and the trends in regulation

Abstract

In this paper the history of noise control legislation, its implementation and the possible future trends in legislation are outlined from the perspective of the electricity generation industry. The risks resulting from long-term noise exposure at noise levels associated with power plant operation are examined in some detail, but other effects such as stress, performance and heart disease are also considered. It is concluded that the current Noise at Work Regulation 1989 mandatory limit for employee noise exposure of 90 dB(A) Leq (8 h) and the lower advisory limit of 85 dB(A) Leq (8 h) are unlikely to be reduced in the medium term. However, the lower advisory limit is commonly applied as a mandatory level within the power industry. The practical implications of this decision are usually that such control is exercised at a sound level of 85 dB(A), rather than a noise exposure level of 85 dB(A) Leq (8 h). Where such a policy is implemented the noise-induced hearing loss element within overall hearing loss will become extremely small. This trend and the threshold risk levels suggest that in the future the two regulatory limits might eventually be reduced, respectively, by 5 dB(A). There are technical and practical limitations to the benefits arising from hearing protector usage so that the legal requirement ‘to reduce the risk of hearing damage… to the lowest level reasonably practical’ requires greater emphasis upon the need to reduce noise emission at source. It is possible that the inclusion of noise within the integrated pollution, prevention and control regulations during 1999 will give some impetus to this aim. Finally, it is shown that there is no conclusive evidence to date that demonstrates ‘that disease is caused or aggravated by noise exposure at sound pressure levels insufficient to cause hearing impairment’.