title: Environmental tobacco smoke exposure among non-smoking waiters: measurement of expired carbon monoxide levels.
abstract: BACKGROUND
  Exposure to environmental tobacco smoke is a health risk that is of concern to patrons and of particular concern to employees of restaurants and bars.
  
  
  OBJECTIVE
  To assess environmental tobacco smoke exposure (using expired carbon monoxide levels) in non-smoking waiters before and after a normal day's shift and to compare pre-exposure levels with non-smoking medical students.
  
  
  METHODS
  An observational study.
  
  
  METHODS
  Restaurants with more than 50 tables or 100 places in São Paulo.
  
  
  METHODS
  100 non-smoking restaurant waiters and 100 non-smoking medical students in São Paulo, Brazil.
  
  
  METHODS
  Levels of expired carbon monoxide, measured with a Smokerlyser (Bedfont EC 50 Scientific), before and after a normal day's work.
  
  
  RESULTS
  Waiters' pre-exposure expired carbon monoxide levels were similar to those of medical students, but after a mean of 9 hours exposure in the workplace, median levels more than doubled (2.0 ppm vs. 5.0 ppm, P <0.001). Post-exposure carbon monoxide levels were correlated with the number of tables available for smokers (Kendall's tau = 0.2, P <0.0001).
  
  
  CONCLUSIONS
  Exposure to environmental tobacco smoke is the most likely explanation for the increase in carbon monoxide levels among these non-smoking waiters. These findings can be used to inform the ongoing public health debate on passive smoking.
authors.affiliation: UNIAD - Alcohol and drugs research unit, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Laranjeira
authors.forename: S
authors.initials: S
authors.lastname: Pillon
authors.forename: J
authors.initials: J
authors.lastname: Dunn
mesh_terms: D000293:Adolescent; D000328:Adult; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D012147:Restaurants; D018709:Statistics, Nonparametric; D013337:Students, Medical; D014028:Tobacco Smoke Pollution / Q000032:analysis*; D017132:Workplace
chemical_list: D014028:Tobacco Smoke Pollution; D002248:Carbon Monoxide