Summary

The authors examined the combined effect of noise and exposure to chemical substances on hearing by using human and animal data from the scientific literature. They note that there are only some fifty studies that characterize exposure to both noise and chemical substances with sufficient precision and reliability. In addition, the definitions given for exposure to a “strong” or “weak” noise vary from one study to the next. The result is that it is very difficult to combine all of the data to arrive at solid conclusions. Of all the articles consulted, there are only two cases of interaction with noise: toluene and noise acting synergistically, and carbon monoxide possibly potentiating the effect of noise. This does not exclude the possibility that other chemical substances can worsen hearing losses due to noise. The authors encourage workplace preventionists to stay abreast of any new information on this protential problem.