A new study published online last week in the Journal of Occupational and Environmental Hygiene provides strong new evidence that passive vaping poses very little health risk, at least for MarkTen e-cigarettes, the brand used in the study.
(See: Maloney JC, et al. Insights from two industrial hygiene pilot e-cigarette passive vaping studies. Journal of Occupational and Environmental Hygiene, November 17, 2015, doi: 10.1080/15459624.2015.1116693.)
In the study, a series of six 1-hour vaping sessions were held over the course of a 12-hour day in a 137 cubic meter room designed to simulate a conference room setting. MarkTen e-cigarettes were used. The room air exchange rate was approximately 1.5 per hour. Active air sampling was employed, both under background and vaping conditions. Air samples were analyzed for propylene glycol, glycerine, nicotine, menthol, particulate matter, and formaldehyde.
The major study results were as follows: "Results of the active samples were below the limit of quantitation of the analytic methods. Near real-time data were below the lowest concentration on the established calibration curves. Data from this study indicate that the majority of chemical constituents [all but formaldehyde] were below quantifiable levels. Formaldehyde was detected at consistent levels during all sampling periods [the levels were no different during vaping compared to background]."
The study concludes: "These two studies found that indoor vaping of MarkTen prototype e-cigarette does not produce chemical constituents at quantifiable levels or background levels using standard industrial hygiene collection techniques and analytical methods."
The study was conducted and reported by scientists at Altria Client Services.
The Rest of the Story
In summary, this study showed that under realistic conditions of vaping in a public place, MarkTen e-cigarettes did not produce ambient levels of propylene glycol, glycerine, nicotine, menthol, or particulate matter above detectable levels, and that while formaldehyde was detected, it was present at background levels measured without vaping occurring.
The results of the study suggest that there is minimal risk associated with passive vaping under realistic conditions, at least with the use of MarkTen e-cigarettes. Of course, one cannot determine from this study whether risks associated with the vaping of other brands of e-cigarettes would be similar. Thus, it is important for similar studies to be conducted with all brands of e-cigarettes.
Importantly, however, the study demonstrates that it is possible to produce an electronic cigarette that produces very low risk of adverse health effects upon bystanders. In this study, exposure of bystanders to nicotine, propylene glycol, menthol, particulates, and formaldehyde was not a problem.
Based on the overall evidence to date, any conclusion that passive vaping poses a substantial public health risk is not justified. Therefore, I would argue that there is not a sufficient scientific basis to support bans on vaping in all public places, as there is with secondhand smoke.
It should also be recognized that an additional benefit of electronic cigarettes is that they may be effective in reducing or eliminating secondhand smoke exposure for many nonsmokers in the population, especially for children living in homes with smokers who were previously smoking in the home but who are able to switch to vaping. This is an additional benefit of electronic cigarettes that has not adequately been considered in previous cost-benefit analyses.