Hearing loss is still one of the most prevalent occupational diseases in the United States and most other
industri alized countries (1-3).
In the United States at least one million workers in manufacturing are estimated to have sustained job-related hearing impairment, and about a half million of these workers have moderate to severe hearing impairment (I ).
Occupational hearing loss has long been recognized as a direct health effect of overexposure to noise, but only
recently has expo sure to solvents been considered as a contributor to the development of hearing impairment (4-10). There is evidence which suggests that noise interact'> synergistically with various drugs and chemicals (11-18).
Evidence is also beginning to accumulate which suggests that an ototraumatic interaction may exist between noise and organic solvents.
Data on the ototoxic effects of solvents like toluene, xylene, and styrene come mainly from limited
animal studies and case report s on substanceabusers (19-24).