Noise exposure is a well-known contributor to work-related hearing loss. Recent biological evidence suggests that exposure to ototoxic chemicals such as organic solvents and heavy metals may be additional contributors to hearing loss.
Some studies suggest that the effect of noise may be enhanced by ototoxic chemicals. Therefore, this study investigated whether co-exposure to organic solvent and/or heavy metals in the workplace modifies the risk of noise exposure on hearing loss in a background of excessive noise.
30,072 workers were examined nationwide in a wide range of industries. Data on industry exposure and subject-specific health outcomes were collected.
The results showed that pure-tone averages (PTA) increments with occupational noise were 1.64-fold and 2.15-fold higher in individuals exposed to heavy metals and organic solvents than in unexposed workers.
In conclusion, the study proves nationwide evidence that co-exposure to these chemicals may increase the risk of hearing loss in workers. The findings suggest that workers in industries dealing with heavy metals and organic solvents are susceptible to such risks.