A CASE-CONTROL STUDY ON CHEMICAL EXPOSURE AND HEARING LOSS AT WORK PLACE

Abstract

Some researches reported that exposed to chemical led workers hearing impairment. In the review of literature, the chemicals be pointed out consistently by many investigators that could be dangerous to human hearing system: trichlorethylene, benzene compounds (including toluene, styrene, and xylene), carbon disulfide (CS2), arsenic, and heavy metals (such as, organic mercury, organic tin). Researches at present revealed a major question that still is incapable to clarify the toxic and interaction of noise and chemicals to the human hearing system. Currently, the main cause of worker hearing impairment is noise, and most of workers who exposed to the chemical were still exposed to noise. In this matter, some reports stated that the chemical exposure might be a ‘contributor’ to their hearing loss. The effects of the chemical to hearing loss are synthetic factors to their noise exposure. We used the cases of hearing loss (hearing threshold more than 40 dB) in the Kaohsiung Medical University Hospital, selecting their age below 65 year-old, without mid-ear diseases, matched the controls from the center of health examination with the same gender and similar age levels (± 3 years) and look for to get the approval accept the questionnaire to collect the matters of chemistry exposures, organic solvent (such as the benzene ethyl- benzene, styrene, toluene, polychlorinated biphenyls) exposures, the antibiotic uses, anti-cancer drugs. The results of this case-control study showed that the odds ratio of cases increased by 50% to 3.5, after adjusting smoking, drinking alcohol, and exposure of noise in the resident environment of the report.