title: Exposure to tobacco smoke based on urinary cotinine levels among Israeli smoking and nonsmoking adults: a cross-sectional analysis of the first Israeli human biomonitoring study.
abstract: BACKGROUND
  Cotinine levels provide a valid measure of exposure to environmental tobacco smoke (ETS). The goal of this study was to examine exposure to tobacco smoke among smoking and nonsmoking Israeli adults and to identify differences in ETS exposure among nonsmokers by socio-demographic factors.
  
  
  METHODS
  We analyzed urinary cotinine data from the first Israeli human biomonitoring study conducted in 2011. In-person questionnaires included data on socio-demographic and active smoking status. Cotinine levels were measured using a gas chromatography-mass spectrometry procedure. We calculated creatinine-adjusted urinary cotinine geometric means (GM) among smokers and nonsmokers, and by socio-demographic, smoking habits and dietary factors. We analyzed associations, in a univariable and multivariable analysis, between socio-demographic variables and proportions of urinary cotinine ≥1 μg/l (Limit of Quantification = LOQ) or ≥4 μg/l.
  
  
  RESULTS
  Cotinine levels were significantly higher among 91 smokers (GM = 89.7 μg/g creatinine; 95% confidence interval [CI]: 47.4-169.6) than among 148 nonsmokers (GM = 1.3; 1.1-1.7). Among exclusive waterpipe smokers, cotinine levels were relatively high (GM = 53.4; 95% CI 12.3-232.7). ETS exposure was widespread as 62.2% of nonsmokers had levels ≥ LOQ, and was higher in males (75.8%) than in females (52.3%). In a multivariable model, urinary cotinine ≥ LOQ was higher in males (Prevalence ratio [PR] = 1.30; 95% CI: 1.02-1.64, p = 0.032) and in those with lower educational status (PR = 1.58; 1.04-2.38, p = 0.031) and decreased with age (PR = 0.99; 0.98-1.00, p = 0.020, per one additional year). There were no significant differences by ethnicity, residence type or country of birth.
  
  
  CONCLUSIONS
  Our findings indicate widespread ETS exposure in the nonsmoking Israeli adult population, especially among males, and younger and less educated participants. These findings demonstrate the importance of human biomonitoring, were instrumental in expanding smoke-free legislation implemented in Israel on July 2012 and will serve as a baseline to measure the impact of the new legislation.
authors.affiliation: Braun School of Public Health and Community Medicine, Hebrew University-Hadassah Faculty of Medicine, Kiryat Hadassah, Ein Kerem, Jerusalem, Israel. hlevine@hadassah.org.il.
authors.forename: Hagai
authors.initials: H
authors.lastname: Levine
authors.forename: Tamar
authors.initials: T
authors.lastname: Berman
authors.forename: Rebecca
authors.initials: R
authors.lastname: Goldsmith
authors.forename: Thomas
authors.initials: T
authors.lastname: Göen
authors.forename: Judith
authors.initials: J
authors.lastname: Spungen
authors.forename: Lena
authors.initials: L
authors.lastname: Novack
authors.forename: Yona
authors.initials: Y
authors.lastname: Amitai
authors.forename: Tamy
authors.initials: T
authors.lastname: Shohat
authors.forename: Itamar
authors.initials: I
authors.lastname: Grotto
mesh_terms: D000328:Adult; D000368:Aged; D003367:Cotinine / Q000652:urine*; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine