Toxic solvents in car paints increase the risk of hearing loss associated with occupational exposure to moderate noise intensity.

Solvents in car paints are a recognised source of occupational toxicity. In particular, they can cause DNA damage and occupational rhinobronchitis. However, little is known about their toxic effect in noise-induced hearing loss (NIHL) in humans. In this study, a 160 pure tone audiometric test was performed in workers in two independent factories to investigate whether toxic solvents in car paints can result in noise-induced hearing loss in workers exposed to moderate noise levels of less than 85 decibels (dB). It is shown that toxic solvents in car paints increase the risk associated with moderate noise exposure of less than 85 dB, with levels of NIHL being similar to those in workers exposed only to loud noises between 92.5 dB and 107 dB. Tinnitus and spells of dizziness were associated symptoms in all workers with NIHL, and asthma was an associated disease in workers with NIHL exposed to car paints and moderate noises simultaneously. These results may indicate that toxic solvents in car paints act in synergism with moderate noise exposure, damaging the cochlear hair cells. The results also constitute firm grounds for monitoring the hearing of these workers and adherence to strict regulations about wearing special gowns and filtered masks during working hours to protect against this preventable occupational disease.