Prevalence of noise-induced hearing loss in metallurgical company

Abstract

OBJECTIVE: To analyze the prevalence of cases suggestive of noise-induced hearing loss (NIHL) among metalworkers who were potentially exposed to occupational noise (from 83 to 102 dB). METHODS: A cross-sectional study was carried out in a metalworking company providing services in Rio de Janeiro, Brazil. Clinical and occupational data on 182 workers who were active between November 2001 and March 2002 were obtained from the company's Hearing Conservation Program and analyzed. In order to characterize the noise exposure status within the work environment, the acoustic classifications from the operating units of the client companies were used, due to difficulty in quantification at an individual level. Associations between these cases and variables such as age, length of service in the company, length of exposure to occupational noise and degree of use of individual protection equipment were tested by means of prevalence ratios and logistic regression analysis. RESULTS: The prevalence of cases suggestive of NIHL was 15.9% and significant associations (p<0.05) were identified from multivariate analysis between these cases and the variables of age and degree of use of individual protection equipment. CONCLUSIONS: The results found contribute towards better understanding of the behavior of some of the main characteristics of NIHL, in a particular situation of the organizing of work that is relatively common in the Brazilian industrial context.