Occupational noise exposure and hearing loss among pulse processing workers

Abstract

Occupational noise exposure and noise-induced hearing loss (NIHL) has been recognised as a problem among workers in Indian industries. The major industries in India are based on the processing of agricultural products. There are appreciable numbers of pulse processing units spread throughout the country. The purpose of this study was to determine the prevalence of hearing loss among pulse processing workers. As a part of hearing protection intervention, audiometric tests were conducted at the binaural low (250–1,500 Hz), the binaural mid (1,500–4,000 Hz) and the binaural high (3,000–8,000 Hz) frequency averages. The prevalence of hearing loss was determined based on hearing threshold levels (HTLs) with a low fence of 25 dB. Over 50% of pulse processing workers (dana bazaar and dal mill) showed hearing loss in the noise-sensitive higher (binaural mid and high) frequencies. The rate of hearing loss was particularly high among workers in the dal mill. The analyses show a higher risk of prevalence of hearing loss among the dal mill workers compared to the workers associated with the grain preprocessing activities. The study shows alarming signals of NIHL, especially in the dal mill workers. The occupational exposure to noise could be minimised by efficient control measures through engineering controls, administrative controls and the use of personal protective devices. Applications of engineering and/or administrative controls are frequently not feasible in developing countries for technical and financial reasons. A complete hearing conservation programme, including training, audiometry and the use of hearing protection devices, is the most feasible method for the protection of industrial workers from prevailing noise in workplace environments in the developing countries.