Abstract:

The effect of noise exposure in combination with other ototraumatic agents (e.g., solvents, metals, and pharmacologic agents) is an emerging area of concern for the development of comprehensive standards for hearing loss prevention. Noise exposure primarily damages the organ of Corti, while solvent exposures exhibit both central and peripheral effects in rats. Organic solvent-induced hearing loss presents impairment which is similar to noise-induced hearing loss in humans. Exposures to metals tend to affect the central nervous system. The effects of lead exposure on auditory brainstem response exhibit an increased threshold across all frequencies and increased latencies in humans. However, other metals, such as zinc and copper, do not produce similar effects. Combined exposures of noise with metals or solvents can produce nonadditive interactions both in humans and animals. This paper reviews the effects of exposure to commonly used organic solvents and metals found in occupational settings. The interactions of several solvents and metals will be classified according to their effects on the peripheral or central auditory system both in laboratory animals and humans.