Medical Journal of The Islamic Republic of Iran (MJIRI)

  Abstract

  Background : Noise is the most common hazard in the workplace and noise induced

  hearing loss considered to be the most common occupational disease as well.

  Cigarette smoking, in some studies, has been known to induce hearing loss. The purpose

  of this study was to evaluate the effect of contemporary exposure to occupational

  noise and cigarette smoking on hearing.

  Methods : 478 assembly workers of an automobile plant which were exposed to

  the noise more than TLV (threshold limit value) level included in this study. After

  considering the exclusion criteria, all participants according to the smoking status

  were divided in smoker and nonsmoker groups and compared for hearing impairment.

  Hearing impairment in this study was assessed with the offered method of

  American Academy of Otolaryngology (AAO).

  Results : Of 478 assembly workers, 225 persons were smokers and others non

  smokers. Prevalence of hearing impairment in smokers was significantly higher

  (p<0.001). Hearing impairment had a significant relation with smoking status even

  after adjusting for cofounders like age and duration of work (OR=8.23, 95%

  CI=3.63-18.66).

  Conclusion : The results of this study suggested that cigarette smokers had more

  hearing impairment than non smokers. According to these results we concluded that

  in working environments, especially in noisy ones, workers must be encouraged to

  quit smoking and regular audiometric tests, especially for smokers, must be applied.

  We must consider not only the noise, but indeed all effective elements of hearing impairment

  in working environment that could compromise the hearing.