PURPOSE: To assess the hearing status and signs of significant auditory threshold shifts in meat-processing facility workers who are exposed to noise levels below nationally and internationally recommended exposure limits, and to compare these results with data from workers exposed to excessive noise levels. METHODS: Longitudinal audiometric data from 266 workers were evaluated, and only workers with a minimum of three audiometric test results and noise exposure records were selected for this study. The 63 assessments selected were classified according to subjects' noise exposure into three levels: 79 to 84.9 dB(A), 85 to 89.9 dB(A), and 90 to 98.9 dB(A). Occurrences of hearing loss and significant auditory threshold shifts were assessed, in each group. RESULTS: Differences in the mean thresholds were observed in all test frequencies among the different groups. A significant correlation was found between occurrence of noise-induced hearing loss and duration of noise exposure (in years) at the present industrial facility (R=0.373; p=0.079). Significant auditory threshold shifts were found in all three levels of noise exposure. CONCLUSION: The findings of the present study suggest the existence of an association between significant auditory threshold shifts in workers and the years of exposure to low risk noise levels.
Permissible limits; Legislation as topic; Hearing loss; noise-induced hearing loss; Occupational exposure; Noise, occupational
