Exhaled electronic cigarette emissions What’s your secondhand exposure?

By Jonathan Thornburg, Quentin Malloy, Seung-Hyun Cho, William Studabaker, Youn Lee

Electronic cigarettes (e-cigarettes) are a new category of nicotine delivery devices designed to closely mimic the experience of smoking conventional cigarettes. Little is known about the factors of e-cigarettes that determine non-user (secondhand) exposures that result from the vapors exhaled by the user. We found that the manufactured qualities of the e-cigarette device and the composition of the liquid determine the quantity, size, and chemical composition of the particles and vapors exhaled by the user. These factors determine the air concentration of the e-cigarette emissions and their residence time within the environment, which lead to potential secondhand exposures.


Thornburg, J., Malloy, Q., Cho, S-H., Studabaker, W., & Lee, Y. (2015). Exhaled electronic cigarette emissions: What’s your secondhand exposure? (RTI Press Publication No. RB-0008-1503). Research Triangle Park, NC: RTI Press. https://doi.org/10.3768/rtipress.2015.rb.0008.1503

© 2019 RTI International. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.


Jonathan ThornburgJonathan Thornburg received his PhD in aerosol physics and engineering from the University of North Carolina at Chapel Hill. He is Director of Exposure and Aerosol Technology at RTI International. His research interests over several decades involve four key areas of expertise: (1) development of aerosol exposure instrumentation, (2) aerosol exposure modelling, (3) understanding the physical and chemical properties of aerosols and (4) understanding aerosol fate and transport in outdoor and indoor environments. These cornerstones are applied in laboratory and field studies to effectively research the entire exposure-dose-response paradigm. He recently led a study of e-cigarette emissions characteristics and the potential for second-hand exposure. The study found that emissions are a mixture of nanometer-size particles and vapors composed of the carrier liquid, nicotine, flavorings, and artificial colors. Respiratory deposition modelling predicted that more than half of the emissions are exhaled into the ambient air by the user, so the potential for second-hand exposure is high.

Quentin MalloyQuentin Malloy, PhD, is an aerosol engineer at RTI. His research interests are aerosol chemistry and instrumentation and their relationship to personal exposure.

Seung-Hyun ChoSeung-Hyun Cho, PhD, is an aerosol engineer at RTI. Her research interests are personal exposure to aerosols and gases, and deposition within a person’s respiratory tract.

William StudabakerWilliam Studabaker, PhD, is the manager of RTI’s Trace Organic Chemistry program. His specialty is analytical chemistry methods for detection of trace organics in environmental and biological samples.

Youn LeeYoun Ok Lee, PhD, is a public health analyst at RTI. Her research interests include the implications of tobacco and vapor product marketing and design on public policy, regulation, and health behavior.

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