Occupational noise exposure and hearing loss of workers in two plants in eastern saudi Arabia

Objective: To determine the prevalence of hearing loss associated with occu pational noise exposure and other risk factors. Design: A cross-sectional study involving 269 exposed and 99 non-exposed su bjects (nonindustrial noise exposed subjects) randomly selected, Current no ise exposure was estimated using both sound level meter and noise-dosimeter . Past noise exposure was estimated by interview questionnaire. Otoscopic e xamination and conventional frequency (0.25-8 kHz) audiometry were used to assess the hearing loss in each subject. Results: 75% (202 subjects) from the exposed group were exposed to a daily Leg above the permissible level of 85 dB(A) and most (61%) of these did not and had never used any form of hearing protecion, Nearing loss was found t o be bilateral and symmetrical in both groups. Bivariate analysis showed a significant hearing loss in the exposed vs non-exposed subjects with a char acteristic dip at 4 kHz, Thirty eight percent of exposed subjects had heari ng impairment, which was an 8-fold higher rate than that found for non-expo sed subjects. Multivariate analysis indicated exposure to noise was the pri mary, and age the secondary predictor of hearing loss. Odds of hearing impa irment were lower for a small sub-group of exposed workers using hearing pr otection (N=19) in which logistic regression analysis showed the probabilit y of workers adopting hearing protective devices increased with noise expos ure, education, acid awareness of noise control, Hearing loss was also grea ter amongst those who used headphones to listen to recorded cassettes. Conclusion: Gross occupational exposure to noise has been demonstrated to c ause hearing loss and the authors believe that occupational hearing loss in Saudi Arabia is a widespread problem, Strategies of noise assessment and c ontrol are introduced which mag help improve the work environment. (C) 2001 British Occupational Hygiene Society. Published by Elsevier Science Ltd. A ll rights reserved.