Original scientific paper
https://doi.org/10.2478/10004-1254-61-2010-2013
Combined Effects of Ototoxic Solvents and Noise on Hearing in Automobile Plant Workers in Iran
Saber Mohammadi
; Department and Occupational Medicine Research Center of Iran University of Medical Sciences, Tehran, Iran
Yasser Labbafinejad
; Department and Occupational Medicine Research Center of Iran University of Medical Sciences, Tehran, Iran
Mirsaeed Attarachi
; Department and Occupational Medicine Research Center of Iran University of Medical Sciences, Tehran, Iran
Abstract
Exposure of workers to mixtures of organic solvents and to occupational noise is frequent in a number of industries. Recent studies suggest that exposure to both can cause a more severe hearing loss than exposure to noise alone. Our cross-sectional study included 411 workers of a large automobile plant divided in three
groups. The fi rst group included assembly workers exposed to noise alone; the second included workers in a new paint shop, who were exposed to a mixture of organic solvents at a permissible level; and the third group included paint shop workers exposed to both noise and higher than permissible levels of organic solvents in an old paint shop. These groups were compared in terms of low-frequency hearing loss (model 1; average hearing threshold >25 dB at 0.5 kHz, 1 kHz, and 2 kHz) and high-frequency hearing loss (model
2; average hearing threshold >25 dB at 3 kHz, 4 kHz, 6 kHz, and 8 kHz). High-frequency hearing loss was more common in workers exposed to a combination of noise and mixed organic solvents even at permissible levels than in workers exposed to noise alone even after correction for confounding variables. This study shows that combined exposure to mixed organic solvents and occupational noise can exacerbate hearing loss in workers. Therefore, an appropriate hearing protection programme is recommended, that would include short-interval audiometric examinations and effi cient hearing protectors.
Keywords
assembly line; hearing loss; occupational exposure; paint shop
Hrčak ID:
58418
URI
Publication date:
17.9.2010.
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