title: Cigarette smoking and occupational noise-induced hearing loss.
abstract: BACKGROUND
  Noise is the most common occupational hazard. Noise-induced hearing loss (NIHL) is a known occupational disease. The economic costs of NIHL have been estimated to be billions of dollars. Besides, cigarette smoking is a common habit worldwide.
  
  
  METHODS
  In a cross-sectional study, we surveyed the effect of smoking on NIHL in 504 workers in a large wagon manufacturing company exposed to noise >85 dBA. All required data were obtained using direct interview and questionnaires. To determine noise exposure level, we used industrial hygienist's reports of sound level measurements. A qualified audiologist assessed hearing status using standardized audiometric examination.
  
  
  RESULTS
  We concluded that the frequency of hearing loss in smokers was higher than non-smokers [based on Model 1: odds ratio (OR) = 9.35, 95% confidence interval (CI) = 5.74-15.22 and P-value < 0.001; and based on Model 2: OR = 9.06, 95% CI = 5.93-13.84 and P-value < 0.001]. Besides, these results were confirmed by logistic regression statistical method.
  
  
  CONCLUSIONS
  It can be concluded that smoking may accelerate NIHL, but for confirming this opinion, further studies are warranted.
authors.affiliation: Iran University of Medical Sciences and Occupational Medicine Research Center, Tehran, Iran.
authors.forename: Saber
authors.initials: S
authors.lastname: Mohammadi
authors.forename: Mohammad Mahdi
authors.initials: MM
authors.lastname: Mazhari
authors.forename: Amir Houshang
authors.initials: AH
authors.lastname: Mehrparvar
authors.forename: Mir Saeed
authors.initials: MS
authors.lastname: Attarchi
mesh_terms: D000328:Adult; D000368:Aged; D001299:Audiometry; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006317:Hearing Loss, Noise-Induced / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D007492:Iran; D016015:Logistic Models; D008297:Male; D008420:Manufactured Materials; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects; D016017:Odds Ratio; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires