In this study, simultaneous occupational exposure to excessive levels of toluene and noise were found to increase the predicted probability of developing a hearing Joss significantly among rotogravure printers, when compared with a group of workers exposed to matching doses of noise.
Furthermore, in the paint manufacturing industry, occupational exposure to asolvent mixture containing mainly toluene, xylene, methyl ethyl ketone, and methyl isobutyl ketone was also shown to increase the probability of hearing loss,
with an adjusted relative risk greater than the one obtained in the noise-only group. The positive association
between occupational exposure to solvents and hearing disorders raises serious concerns.
Hitherto, occupational hearing conservation programs have not taken chemical exposures into consideration.
Thus there may be numerous workers with unmet needs concerning hearing conservation.