The global burden of occupational noise-induced hearing loss

Background Excessive noise is a global occupational health hazard with considerable social and physiological impacts, including noise-induced hearing loss (NIHL). This paper describes the worldwide morbidity of occupational NIHL in the year 2000. Methods The proportion of the population exposed to occupational noise was estimated using noise exposure data from the US National Institute for Occupational Safety and Health (NIOSH), adjusted by data on the distribution of the workforce by occupational category and economic sector, and economic activity rates in each WHO subregion. These values for the exposed population and risk measures for NIHL were used to develop estimates o the attributable fraction (AF) of adult-onset hearing loss resulting from occupational noise exposure. The AFs were applied to WHO estimates of total disabilityadjusted life years (DALYs) from adult-onset hearing loss to estimate the DALYs due to occupational noise. Results Worldwide, 16% of the disabling hearing loss in adults (over 4 million DALYs) is attributed to occupational noise, ranging from 7% to 21 % in the various subregions. The effects of the exposure to occupational noise are larger for males than females in all subregions and higher in the developing regions. Conclusions Occupational noise is a significant cause of adult-onset hearing loss. The majority ofthis NIHL burden can be minimized by the use ofengineering controls to reduce the generation of noise at its source. Am. J. Ind. Med. 48:446-458, 2005. (c) 2005 Wiley-Liss, Inc.