Exposure to organic solvent mixture and hearing loss: literature overview

The chemical sector is the third largest industry in Europe. There is increasing evidence from epidemiological and clinical studies that occupational exposures to organic solvents may have detrimental effect on hearing. Most of the literature data concern one of the three following types of exposure to industrial solvents: mixed solvent exposure (the most common type); styrene-only exposure; and toluene-only exposure. This paper overviews the effects of industrial exposure to a mixture of organic solvents on hearing, with special regard to the dose-response relationship. Although the existing data make it difficult to derive a correlation between solvent concentration and hearing outcome, the current occupational exposure limits for solvents seem to be inadequate with respect to the effect that solvents may have on the auditory system.