The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real-world conditions

Introduction:
This text is a summary of an exposure study that investigates the impact of three electronic cigarette (e-cigarette) models on indoor fine and ultrafine particulate matter (PM) concentrations under real-world conditions. The study aims to estimate concentrations of PM2.5 and UFPs from indoor e-cigarette use at 0.5 meters and 1 meter away from an e-cigarette user and to compare the concentrations produced by the three e-cigarette models.

Key Points:

* The study found that e-cigarette vapors influence PM2.5 and UFP concentrations at close proximity distances indoors.
* Following the initiation of e-cigarette use, levels of PM2.5 increased 160-fold at a distance of 0.5 meters, and 103-fold at 1 meter. The corresponding increases in UFP counts were 5.2, and 3.0-fold higher, respectively.
* The PM2.5 concentrations and UFP counts between e-cigarette models were statistically significantly different at 1 meter, but not at 0.5 meters.
* There was substantial variability between distances, e-cigarettes, and replicates.
* The study did not include an analysis of the chemical constituents resulting from e-cigarette vapors.
* The measurements were taken in a -38m3 office on the fifth floor of a university building with the room's two windows and one door kept closed during testing.
* One volunteer e-cigarette user was situated near the center of the room facing the fine particulate matter measurement devices.
* The identical e-liquid containing 12 mg of nicotine per ml was used in all tests.
* Continuous 1-s interval measurements of PM2.5 and UFPs were taken for 22 min; 5.5 min before (pre), 6.5 min during e-cigarette use (exposure), and 10 min after (post) to observe the return to pre-exposure concentrations.

Main Message:
The key takeaway from this study is that e-cigarette vapors can significantly increase PM2.5 and UFP concentrations at close proximity distances indoors, which may represent a new source of air pollution. The study highlights the need for further research to characterize the composition of those particles and evaluate the impacts of other e-cigarette solutions on indoor air quality. The findings suggest that regulations may be necessary to limit e-cigarette use in indoor environments, particularly in public places where vulnerable populations such as children, the elderly, or those with pre-existing respiratory conditions are present.

Volesky, Karena D., Anthony Maki, Christopher Scherf, Louis Watson, Keith Van Ryswyk, Bruce Fraser, Scott A. Weichenthal, Edana Cassol, and Paul J. Villeneuve. “The Influence of Three E-Cigarette Models on Indoor Fine and Ultrafine Particulate Matter Concentrations under Real-World Conditions.” Environmental Pollution 243 (December 2018): 882–89. https://doi.org/10.1016/j.envpol.2018.08.069.