title: Electronic cigarettes are a source of thirdhand exposure to nicotine.
abstract: BACKGROUND
  Substances remaining on the surfaces in areas where people have smoked contribute to thirdhand exposure. Nicotine from tobacco smoke has been shown to react with oxidizing chemicals in the air to form secondary pollutants, such as carcinogenic nitrosamines. While previous studies have demonstrated thirdhand exposure to nicotine from tobacco smoke, none have investigated whether nicotine from electronic cigarettes (e-cigarettes) can also be deposited on various surfaces.
  
  
  METHODS
  Three brands of e-cigarettes were refilled with varying nicotine concentrations. We released 100 puffs from each product directly into an exposure chamber. Surface wipe samples were taken from 5 indoor 100 cm(2) surfaces (window, walls, floor, wood, and metal) pre- and post-release of vapors. Nicotine was extracted from the wipes and was analyzed using gas chromatography.
  
  
  RESULTS
  Three of the 4 experiments showed significant increases in the amount of nicotine on all five surfaces. The floor and glass windows had the greatest increases in nicotine, on average by a factor of 47 and 6, respectively (p < .05). The average amount of nicotine deposited on a floor during each experiment was 205 μg/m(2) and varied from limit of quantitation to 550 μg/m(2).
  
  
  CONCLUSIONS
  This study indicates that there is a risk for thirdhand exposure to nicotine from e-cigarettes. Thirdhand exposure levels differ depending on the surface and the e-cigarette brand. Future research should explore the potential risks of thirdhand exposure to carcinogens formed from the nicotine that is released from e-cigarettes.
authors.affiliation: Department of Health Behavior, Division of Cancer Prevention and Population Sciences, Roswell Park Cancer Institute, Buffalo, NY maciej.goniewicz@roswellpark.org.
authors.forename: Maciej L
authors.initials: ML
authors.lastname: Goniewicz
authors.affiliation: Department of Health Behavior, Division of Cancer Prevention and Population Sciences, Roswell Park Cancer Institute, Buffalo, NY.
authors.forename: Lily
authors.initials: L
authors.lastname: Lee
mesh_terms: D066300:Electronic Nicotine Delivery Systems / Q000009:adverse effects*; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D009538:Nicotine / Q000009:adverse effects / Q000032:analysis*; D014028:Tobacco Smoke Pollution / Q000032:analysis*
chemical_list: D014028:Tobacco Smoke Pollution; D009538:Nicotine