title: Comparison of exposure to selected cigarette smoke constituents in adult smokers and nonsmokers in a European, multicenter, observational study.
abstract: BACKGROUND
  This multicenter, observational study was conducted in three European countries (Germany, Switzerland, and the United Kingdom) to determine the exposure of adult cigarette smokers and nonsmokers to selected cigarette smoke constituents: 1,3-butadiene, 2-naphthylamine, 4-aminobiphenyl, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), acrolein, benzene, carbon monoxide, nicotine, pyrene, and o-toluidine.
  
  
  METHODS
  Smokers were grouped by tar category (TC) according to the tar yield of their regular cigarette brand: TC1: ≤4 mg tar, TC2: 5-7 mg tar, and TC3: ≥8 mg tar [to the legal tar yield ceiling in the respective countries (10 or 12 mg tar)]. Levels of biomarkers of exposure to the aforementioned cigarette smoke constituents were compared between smokers and nonsmokers, and within smokers across tar categories.
  
  
  RESULTS
  The full population consisted of 1,631 subjects (1,223 smokers and 408 nonsmokers). Biomarkers of exposure were analyzed for 1,558 subjects (valid case population) as follows: 1,159 smokers (TC1: n = 402, TC2: n = 379, TC3: n = 378), and 399 nonsmokers. Exposure levels were higher in smokers than nonsmokers and increased with increasing tar yield and cigarette consumption. An association of tar category and exposure level was observed for all smoke constituents, except pyrene, 4-aminobiphenyl, and o-toluidine, whereas only NNK exposure was different in all three tar categories.
  
  
  CONCLUSIONS
  Smoking status and, among smokers, daily cigarette consumption and tar yield were observed to affect biomarker of exposure levels.
  
  
  CONCLUSIONS
  This research provides a comprehensive evaluation of smoke constituent exposure of adult cigarette smokers and nonsmokers in three European countries.
authors: Philip Morris International R&D, Philip Morris Products S.A., Neuchâtel, Switzerland. dirk.lindner@clinopsis.com
authors: Dirk
authors: D
authors: Lindner
authors: Stephen
authors: S
authors: Smith
authors: Claire Martin
authors: CM
authors: Leroy
authors: Anthony R
authors: AR
authors: Tricker