Conference Paper 1)
Purpose: Electronic cigarettes (e-cigarettes) are new battery-powered devices that resemble tobacco cigarettes and convert nicotine solutions into inhalable vapors.
The e-cigarette vapor contains primarily nicotine dissolved in a propylene glycol or glycerin. Thirdhand exposure occurs when smoke constituents such as nicotine remain on surfaces, are re-emitted into the gas phase, or react with oxidants and other compounds in the environment to form secondary pollutants, such as carcinogenic nitrosamines 2) . Exposure can continue long after smoking has ceased and is a major health concern. We assessed the possibility of the deposition of nicotine on various surfaces as a marker of thirdhand exposure from e cigarettes.
Materials and Methods: Three brands of e-cigarettes were refilled with varying nicotine concentrations and then smoked (“vaped”) with a syringe 3) in an exposure chamber in four experiments. Surface wipe samples were taken from several indoor 100 sq. cm surfaces (window, walls, floor, wood and metal).
Nicotine was extracted with methanol from the wipes and analyzed using gas chromatography with a selective nitrogen-phosphorus detector (GC-NPD). Blank samples were collected from each surface before the experiments to estimate background exposure.
Results: Three out of four experiments showed significant increases in the amount of nicotine on all five surfaces. Some surfaces were easier for nicotine to adsorb to. The floor and glass windows had the greatest increases in nicotine, on average by a factor of 28 and 4, respectively. The average amount of nicotine deposited on a floor during each experiment was 24 ng per sq. cm, and varied from 0.5 to 55 ng per sq. cm.
Conclusions: Our work indicates that nonsmokers can be exposed to nicotine released from e-cigarettes and deposited on surfaces. Thirdhand exposure levels differ depending on the surface and e-cigarette brand, creating the potential danger of e-cigarettes exposing people to carcinogens. Future research should explore the risks of thirdhand exposure to carcinogens from e-cigarettes.
FUNDING: This work was supported by Roswell Park Cancer Institute, National Cancer Institute (NCI) grant #P30 CA016056, and NCI CURE Supplement (LL).
JUSTIFICATION: The findings of this study might inform regulators whether e-cigarettes should be included under smoke-free policies to protect nonusers from inhaling the toxicants. CORRESPONDING AUTHOR: Maciej Goniewicz, Ph.D., Assistant Professor, Roswell Park Cancer Institute, Department of Health Behavior, Elm and Carlton Streets, Buffalo, NY 14263, United States, Phone: 7168458541, Fax: 7168451265, Email: firstname.lastname@example.org