Article Text
Abstract
Objectives In order to estimate the hearing impairment in occupational environment due to the co-exposure to noise and solvents, we have undertaken a cross-sectional study to evaluating the prevalence of hearing loss due the co-exposure to both solvents and noise.
Method We recruited 144 workers, working in electronic materials manufacturing plant, one group is exposed to solvents alone, and the other one exposed to both noise and solvents. In another hand, we followed two other groups in a construction company of farm implements. 136 workers exposed to noise, 96 administrative workers none exposed. The data were collected by means of questionnaire and of an introductory tonal audiometry between 0,125 and 8 KHz
Results The prevalence of hearing loss of more 20dB in the group exposed to the noise and solvents was mush greater (57. 8%) than that of the noise alone (35. 3%), and that of administrative workers (27.7%) (P < 0.0001).
Multivariate logistic regression analysis showed that the solvents and noise group had an estimated risk for hearing loss >20 dB about 4.4 times higher than that of the noise group.
Hearing impairment was greater for speech frequency than for high frequency.
Conclusions Our results suggest that solvents increase potentially the hearing loss in a noisy environment, with a higher impact on the speech frequencies.