title: Waterpipe tobacco and cigarette smoking: direct comparison of toxicant exposure.
abstract: BACKGROUND
  Waterpipe (hookah, shisha) tobacco smoking has spread worldwide. Many waterpipe smokers believe that, relative to cigarettes, waterpipes are associated with lower smoke toxicant levels and fewer health risks. For physicians to address these beliefs credibly, waterpipe use and cigarette smoking must be compared directly.
  
  
  OBJECTIVE
  The purpose of this study is to provide the first controlled, direct laboratory comparison of the toxicant exposure associated with waterpipe tobacco and cigarette smoking.
  
  
  METHODS
  Participants (N=31; M=21.4 years, SD=2.3) reporting monthly waterpipe use (M=5.2 uses/month, SD=4.0) and weekly cigarette smoking (M=9.9 cigarettes/day, SD=6.4) completed a crossover study in which they each smoked a waterpipe for a maximum of 45 minutes, or a single cigarette. Outcome measures included expired-air carbon monoxide (CO) 5 minutes after session's end, and blood carboxyhemoglobin (COHb), plasma nicotine, heart rate, and puff topography. Data were collected in 2008-2009 and analyzed in 2009.
  
  
  RESULTS
  On average, CO increased by 23.9 ppm for waterpipe use (SD=19.8) and 2.7 ppm for cigarette smoking (SD=1.8), while peak waterpipe COHb levels (M=3.9%, SD=2.5) were three times those observed for cigarette smoking (M=1.3%, SD=0.5; p's<0.001). Peak nicotine levels did not differ (waterpipe M=10.2 ng/mL, SD=7.0; cigarette M=10.6 ng/mL, SD=7.7). Significant heart rate increases relative to pre-smoking were observed at 5, 10, 15, 20, 25, and 35 minutes during the cigarette session and at 5-minute intervals during the waterpipe session (p's<0.001). Mean total puff volume was 48.6 L for waterpipe use as compared to 1.0 L for cigarette smoking (p<0.001).
  
  
  CONCLUSIONS
  Relative to cigarette smoking, waterpipe use is associated with greater CO, similar nicotine, and dramatically more smoke exposure. Physicians should consider advising their patients that waterpipe tobacco smoking exposes them to some of the same toxicants as cigarette smoking and therefore the two tobacco-smoking methods likely share some of the same health risks.
authors: Department of Psychology and Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, Virginia 23298, USA. teissenb@vcu.edu
authors: Thomas
authors: T
authors: Eissenberg
authors: Alan
authors: A
authors: Shihadeh
mesh_terms: D000293:Adolescent; D000328:Adult; D002248:Carbon Monoxide / Q000032:analysis*; D018592:Cross-Over Studies; D004867:Equipment Design; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008875:Middle Aged; D012907:Smoking; D014028:Tobacco Smoke Pollution / Q000032:analysis*; D014768:Virginia; D014867:Water; D055815:Young Adult
chemical_list: D014028:Tobacco Smoke Pollution; D014867:Water; D002248:Carbon Monoxide