Evaluation of low-cost aerosol and gas sensors for real-time measurements of electronic cigarette exposure

Abstract

Indoor electronic cigarette (e-cigarette) use exposes bystanders to airborne PM_2.5 (particulate matter 2.5 µm and smaller) and volatile organic compounds (VOCs). To understand potential risks for bystanders, measuring real-time e-cigarette exposure is important. However, no study evaluates the performance of low-cost sensors for real-time measurements of indoor e-cigarette aerosol concentrations. Thirty-two low-cost GeoAir2 monitors were used to detect e-cigarette-generated PM_2.5 and VOCs inside a controlled laboratory exposure chamber. The GeoAir2 was compared to an OPC-N3 low-cost monitor and the MiniWRAS and MiniRae reference instruments. Three e-cigarette devices (JUUL, NJOY Daily, and VOOPOO DRAG 2) were used to generate emissions using a diaphragm pump programmed to puff based on e-cigarette-user puffing behaviors. The GeoAir2 PM_2.5 concentrations were similar to the raw MiniWRAS PM_2.5 concentrations for different e-cigarettes. For the JUUL, PM_2.5 measurements were close or on the 1-1 line, for the NJOY Daily measurements were on the 1-1 line for concentrations lower than 200 µg/m³, and PM_2.5 measurements were overestimated for the VOOPOO DRAG 2 (mean correlation ≥ 0.97). The OPC-N3 significantly underestimated concentrations compared to the raw and filter-corrected MiniWRAS concentrations (mean correlation ≥ 0.98). The GeoAir2 VOC concentrations compared to the MiniRAE were on the 1-1 line for the VOOPOO DRAG 2, overestimated for the JUUL and NJOY Daily (mean correlation ≥ 0.98). These results show that GeoAir2 is an effective tool for examining e-cigarette use in indoor settings, such as homes, vehicles, workplaces, vape shops, or other locations, to better understand bystander exposures to e-cigarette aerosols.

Copyright © 2022 American Association for Aerosol Research

GRAPHICAL ABSTRACT

EDITOR:

• Mark Swihart

Acknowledgments

The authors would like to thank Ms. Nicole Bertges for her help revising the Introduction section.

Disclosure statement

Eric Soule is named on a patent application for a device that determines electronic cigarette device and liquid characteristics.

Data availability statement

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

Additional information

Funding

This research is supported by grant number R15ES032138 and P30ES025128 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.