[Hearing loss associated with smoking in male workers]

A cross-sectional study was designed to examine the effect of smoking habit on hearing loss at 1000 and 4000 Hz in the workplace. Among 1,875 male workers, including 287 subjects with occupational noise exposure, the ratio of the number with hearing loss at 1000 or 4000 Hz increased with smoking habits and that relation at 4000 Hz was statistically significant. These hearing losses showed a significant relation with age but not with working- duration under occupational noise exposure by multiple regression analysis. The amount of smoking showed a weak but significant association with hearing loss at 4000 Hz. However, among the 287 male subjects with occupational noise exposure, there was no significant relation between smoking habits and hearing loss. Therefore, both hearing loss induced by occupational noise exposure and that related with smoking habit were well controlled in this workplace. These results indicate that hearing check-ups and education to prevent noise-induced hearing impairment in the workplace might be useful to prevent the hearing loss associated with smoking habit among male workers.