Secondhand Exposure to Vapors From Electronic Cigarette

Introduction:

Electronic cigarettes (commonly referred to as e-cigarettes) are designed to generate inhalable nicotine aerosol (vapour). When an e-cigarette user takes a puff, the nicotine solution is heated and the vapour is taken into the lungs. Although no sidestream vapour is generated between puffs, some of the mainstream vapour is exhaled by an e-cigarette user. The aim of the study was to evaluate secondhand exposure to nicotine and other tobacco-related toxicants from e-cigarettes.

Materials and Methods:

We measured selected airborne markers of secondhand exposure: nicotine, aerosol particles (PM_2.5), carbon monoxide, and volatile organic compounds (VOCs) in an exposure chamber. We generated e-cigarette vapour from 3 various brands of e-cigarettes using a smoking machine and controlled exposure conditions. We also compared secondhand exposure with e-cigarette vapour and tobacco smoke generated by 5 dual users.

Results:

The study showed that e-cigarettes are a source of secondhand exposure to nicotine but not to combustion toxicants. The air concentrations of nicotine emitted by various brands of e-cigarettes ranged from 0.82 to 6.23 µg/m³. The average concentration of nicotine resulting from smoking tobacco cigarettes was 10 times higher than from e-cigarettes (31.60±6.91 vs. 3.32±2.49 µg/m³, respectively; p = .0081).

Conclusions:

Using an e-cigarette in indoor environments may involuntarily expose nonusers to nicotine but not to toxic tobacco-specific combustion products. More research is needed to evaluate the health consequences of secondhand exposure to nicotine, especially among vulnerable populations, including children, pregnant women, and people with cardiovascular conditions.