Promotion of Noise-Induced Hearing Loss by Chemical Contaminants

Abstract

Recent studies have underscored the ability of a wide range of chemical agents to potentate noise-induced hearing loss. Given the ubiquitous nature of noise exposure particularly in many work settings, the high rate of noise-induced hearing loss, the limited degree to which auditory function can recover following damage to the inner ear, and the disparate chemical structures that appear capable of impairing hearing, this issue appears to have great public health signifi-cance. A compendium of chemicals known to potentiate noise induced hearing loss is presented along with a hypothesis that might explain at least one basis for potentiation of noise-induced hearing loss by certain chemical toxicants. The use of benchmark dose analysis to undertake a risk assessment for promotion of noise-induced hearing loss by both carbon monoxide and hydrogen cyanide is described.

Research reported here was supported in part by grants from NIOSH (OH03481) and at facilities pro-vided by the Jerry Pettis Memorial VA Medical Center, Loma Linda, CA. The author is indebted to Caroline Gearhart and Linda Scher for assistance in preparing this article.