title: Assessment of mouth-level exposure to tobacco constituents in U.S. snus consumers.
abstract: BACKGROUND
  When assessing the health risks associated with different tobacco product categories (e.g., combustible and noncombustible), it is important to understand exposure. Snus, a smokeless tobacco product with lower levels of most tobacco-related toxicants than cigarette smoke, has been recently introduced in the United States. The objective of this study was to evaluate the mouth-level exposure (MLE) to selected tobacco constituents from snus by adult consumers of Camel SNUS (CSNUS).
  
  
  METHODS
  For 7 days, 53 adult CSNUS consumers used their usual brand styles ad libitum, collecting their snus pouches after use. The collected pouches and unused product were analyzed for nicotine, N'-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N'-nitrosoanabasine (NAB), N'-nitrosoanatabine (NAT), benzo[a]pyrene (B[a]P), arsenic, cadmium, chromium, lead, and nickel. MLE was estimated using the difference between the constituent amounts in the used and unused snus products.
  
  
  RESULTS
  CSNUS consumption averaged 3.3 pouches/day or approximately 1.98 g/day. Mean nicotine MLE was 2.8 mg/pouch or 9.4 mg/day. Mean MLE to total tobacco-specific nitrosamines (TSNAs: NNK, NNN, NAB, and NAT) was 171.5 ng/pouch or 527.7 ng/day. B[a]P MLE averaged 0.2 ng/pouch or 0.68 ng/day.
  
  
  CONCLUSIONS
  This study is the first to report snus MLE under normal conditions of use in a group of adult, U.S. snus consumers. On average, approximately 60%-90% of the amounts of nicotine, TSNAs, and B[a]P initially present in a snus pouch remained in the pouch after use by snus consumers in this study. The results from this study provide a preliminary assessment of exposure to constituents present in snus, which is potentially useful in risk assessment.
authors.affiliation: Research and Development, R. J. Reynolds Tobacco Company, Winston-Salem, NC 27102-1487, USA. carawaj@rjrt.com
authors.forename: John W
authors.initials: JW
authors.lastname: Caraway
authors.forename: P X
authors.initials: PX
authors.lastname: Chen
mesh_terms: D000328:Adult; D001564:Benzo(a)pyrene / Q000032:analysis; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008297:Male; D019216:Metals, Heavy / Q000032:analysis; D008875:Middle Aged; D009055:Mouth; D009538:Nicotine / Q000032:analysis; D009602:Nitrosamines / Q000032:analysis; D012907:Smoking / Q000009:adverse effects*; D014030:Tobacco, Smokeless / Q000032:analysis*; D014481:United States; D055815:Young Adult
chemical_list: D019216:Metals, Heavy; D009602:Nitrosamines; D001564:Benzo(a)pyrene; D009538:Nicotine