INCIDENCE AND PREVALENCE OF NOISE INDUCED HEARING LOSS IN WORKERS OF A METALLURGICAL COMPANY IN MANAUS - AM, BRAZIL.

Purpose: to estimate the incidence and prevalence of hearing loss suggestive of Noise Induced Hearing Loss and its association with age and time of service in metallurgical industrial pole workers in Manaus. Methods: cross-sectional study in workers who underwent audiometric testing periodical in 2012, totaling 1499 subjects. To estimate the incidence were selected 763 audiometrys with normal hearing at the reference testing and after compared with the current audiometry. Statistical analyses were performed using measures of central tendency, dispersion and frequency distributions. To verify statistically significant differences, we used the chi-square test, with significance level (p ⩽ 0.05). Results: the prevalence of hearing loss was estimated at 44.23% and 28.89% suggestive of Noise Induced Hearing Loss. There was a higher prevalence of hearing loss among workers aged from 45 years and time of service exceeding 21 years. Only 11.1% of workers over 21 years of service have normal hearing and 61.9% loss of these features suggestive of Noise Induced Hearing Loss. The classification of Not Suggestive of Noise Induced Hearing Loss remains stable in individuals below 20 years of occupational exposure (14.9%), and in people exposed to more than 20 years, increases to 27%. The incidence of hearing loss was 28% and within this total, 19.7% were suggestive of Noise Induced Hearing Loss. Most hearing loss, both suggestive of Noise Induced Hearing Loss, or not, were classified in light. Conclusion: the prevalence and incidence of hearing loss increased with age and time of service. Companies should strive to implement Hearing Conservation Program to minimize these losses. [ABSTRACT FROM AUTHOR]