ASSESSMENT OF AUDITORY FUNCTIONS IN WORKERS EXPOSED TO STYRENE

Abstract

Introduction: Ototoxicity is commonly medication-induced; however, there are increasing scientific data indicating that exposure to some industrial solvents and chemicals, including styrene, are associated with a risk of auditory impairment in humans. Many studies reported auditory system effects and poorer audiometric thresholds in styrene exposed individuals. Aim of work: The aim of the current study is to investigate the relationship between workers exposed to styrene in fibreglass reinforced plastic manufacturing and hearing threshold changes. Materials and Methods: All workers who met the inclusion criteria and agreed to participate in the study were 20 males. A control group of 24 individuals were randomly selected as to be matched with the exposed group. Full medical history was taken including personal, occupational, present, past and family histories. Pure-tone audiometry was done to the studied groups using portable audiogram device. Results: The prevalence of hearing impairment was higher among styrene-exposed group when compared to the non-exposed group; however, difference was not statistically significant. Different degrees of hearing impairment were found among the exposed group (mild, moderate and severe), whereas only a mild degree of hearing impairment was detected among the control group. In addition, there was no significant difference between exposed and non-exposed groups concerning hearing thresholds at all tested frequencies of audiometry in both ears. Conclusion: The results of this study did not support the assumption that occupational exposure to styrene is related to a significant decrease in hearing acuity.