Laboratory determination of gravimetric correction factors for real-time area measurements of electronic cigarette aerosols

Abstract

Research on secondhand electronic cigarette (ECIG) aerosol exposure using aerosol monitors has demonstrated that ECIG use can generate high concentrations of particulate matter (PM) and impact indoor air quality. However, quantifying indoor air PM concentrations using real-time optical monitors with on-site calibration specifically for different PM exposures has not been established. Therefore, the ECIG aerosol filter correction factors were calculated for different PM sizes (PM₁, PM_2.5, and PM₁₀) and different aerosol optical monitors, the MiniWRAS, pDR, and SidePak. ECIG aerosol generation was achieved using five ECIGs representing three ECIG types, disposable, pod-mod, and box mod. The aerosol size distribution by mass was measured for the five ECIGs during PM generation. Compared to the discrete filter measurements, the MiniWRAS performed the best when the concentrations were low, followed by the pDR and SidePak. The average PM concentrations and correction factor ranges for the different ECIGs were 323–1,775 µg/m³ and 0.64–6.01 for the MiniWRAS, 1,388–13,365 µg/m³ and 0.41–0.80 for the pDR, and 4,632–55,339 µg/m³ and 0.13–0.20 for the SidePak, respectively. The mass median diameter ranged from 0.41 to 0.62 µm, and most particles generated from the ECIGs were smaller than 1 µm. This study demonstrates that aerosol size distribution varies between ECIGs. Likewise, the correction factors developed for the real-time aerosol monitors are specific to the ECIG used. Thus, these data can help improve ECIG aerosol exposure measurement accuracy.

Graphical Abstract

EDITOR:

• Mark Swihart

Data availability statement

The datasets generated from the current study are available from the corresponding author on reasonable request.

Acknowledgments

The authors would like to thank Dr. Timothy Wright, formerly of North Carolina State University, for his help during this study

Additional information

Funding

This research is supported by grant number R15ES032138 from the National Institute on Environmental Health Sciences of the National Institutes of Health. Part of E.S.’s efforts is also supported by grant numbers U54DA036105 from the National Institute on Drug Abuse and R21CA239188 from the National Cancer Institute of the National Institutes of Health and the Center for Tobacco Products (CTP) of the U.S. Food and Drug Administration. The content is solely the responsibility of the authors and does not necessarily represent the views of the NIH or the FDA.