title: Kinetics of Exhaled Carbon Monoxide After Water-pipe Smoking Indoors and Outdoors.
abstract: Despite accumulating evidence about its adverse health effects, water-pipe tobacco smoking has become very popular among youth. The aim of this study was to compare smoke exposure and the kinetics of exhaled carbon monoxide (eCO) between water-pipe and cigarette smokers under different conditions.
  
  
  
  Using a cross-over study design, changes in eCO and urinary cotinine levels were measured in a cohort of 32 healthy university students after sessions of water-pipe smoking indoors and outdoors. An indoor cigarette smoking session with equal amounts of tobacco was conducted for reference purposes. Both active and passive smokers participated in all sessions.
  
  
  
  In indoor sessions, we found that among active participants, eCO levels were approximately 7.5-fold higher in water-pipe users than cigarette smokers. eCO levels remained significantly elevated even 10 h after discontinuing water-pipe smoking. Notably, eCO levels in passive water-pipe smokers were in the same range as in active cigarette smokers. Compared with indoor sessions, eCO levels in active water-pipe users were reduced in outdoor environments. Nonetheless, levels were still higher in these subjects than those in active cigarette smokers measured in indoor sessions. Urinary cotinine levels were comparable in active water-pipe and cigarette smokers.
  
  
  
  Our results suggest that water-pipe smoking is associated with significantly higher toxicant exposure than cigarette smoking even in outdoor environments. Furthermore, even passive, indoor water-pipe smoke exposure may have significant health hazards compared with those of active cigarette smoking.
authors.affiliation: Department of Pathophysiology, National Koranyi Institute of TB and Pulmonology, Budapest, Hungary.
authors.forename: Agnes
authors.initials: A
authors.lastname: Juhasz
authors.affiliation: Department of Pathophysiology, National Koranyi Institute of TB and Pulmonology, Budapest, Hungary.
authors.forename: Dalma
authors.initials: D
authors.lastname: Pap
authors.affiliation: Department of Pathophysiology, National Koranyi Institute of TB and Pulmonology, Budapest, Hungary.
authors.forename: Imre
authors.initials: I
authors.lastname: Barta
authors.affiliation: Department of Pathophysiology, National Koranyi Institute of TB and Pulmonology, Budapest, Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Drozdovszky
authors.affiliation: Wessling Hungary Kft, Budapest, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Egresi
authors.affiliation: Department of Pathophysiology, National Koranyi Institute of TB and Pulmonology, Budapest, Hungary; Department of Pulmonology, National Koranyi Institute of TB and Pulmonology, Budapest, Hungary. Electronic address: antusb@hotmail.com.
authors.forename: Balazs
authors.initials: B
authors.lastname: Antus
mesh_terms: D016902:Air Pollution, Indoor; D001944:Breath Tests; D002248:Carbon Monoxide / Q000378:metabolism*; D015331:Cohort Studies; D003367:Cotinine / Q000652:urine; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007700:Kinetics; D008297:Male; D012907:Smoking / Q000378:metabolism*; D062789:Tobacco Products; D014028:Tobacco Smoke Pollution; D055815:Young Adult
chemical_list: D014028:Tobacco Smoke Pollution; D002248:Carbon Monoxide; D003367:Cotinine
keywords: carbon monoxide; smoking; tobacco; water pipe