EFFECTS OF OCCUPATIONAL EXPOSURE TO ORGANIC-SOLVENTS AND NOISE ON HEARING

This study explored the effects of occupational exposure to solvents a nd noise on hearing. Interviews and hearing tests were conducted for p rinting and paint manufacturing workers. The experimental groups inclu ded unexposed (N = 50) workers and workers exposed to noise (N = 50), noise and toluene (N = 51), or an organic solvent mixture (N = 39). Th e risk of hearing loss was greater for the exposed groups than for the unexposed group. The adjusted relative risk estimates were four times greater [95% confidence interval (95% CI) 1.4-12.2] for the noise gro up, 11 times greater (95% CI 4.1-28.9) for the noise and toluene group , and five times greater (95% CI 1.4-17.5) for the solvent-mixture gro up. The findings suggest that exposure to the studied solvents had a t oxic effect on the auditory system and that an interaction between noi se and toluene took place. The audiological results of the noise and t oluene group suggest a central auditory pathway involvement in the hea ring losses observed.