The influence of organic solvents on hearing and balance: A literature review

Abstract

This manuscript presents an overview of current knowledge on the influence of organic solvents on the hearing and balance systems. The authors analyzed - the literature data concerning the results of all human and the most relevant animal studies, published untill 2012. Moreover, the guidelines for occupational medicine specialists were proposed on the basis of literature review and the authors' own scientific experience. The literature data and our studies revealed the increased risk of hearing loss in workers exposed to organic solvents only, and well documented potentiation of harmful effects of combinedexposure to organic solvents and noise. Hearing impairment is mainly observed in high frequencies, but lower frequencies can also be involved (0.5-4 kHz). The impairment induced by exposure to organic solvents is mild, up to several dBs. In the combined exposure to noise and solvents, the noise effect predominates. Organic solvents affect the central pathways of vestibular system although unilateral or bilateral vestibular hypofunction might also be a possible consequence of solvent exposure. Occupational exposure to organic solvents is a risk factor for hearing and balance impairments. Therefore, workers exposed to solvents should be covered by hearing loss prevention programs. Speech in noise test (HINT) and posturography seem to be the most suitable tests for hearing and balance prevention programme for organic solvent exposed workers.