Summary
Introduction:
This article reports a study on the formation of hydroxyl radicals (•Oh), one of the most harmful components in e-cigarette vapor, under various e-cigarette use patterns. The study aims to assess the levels of •Oh in e-vapor under real-world relevant vaping patterns, including device settings, vaping topographies, and e-liquid compositions. The key points and main message of the study are summarized below.
Key Points:
* The study found that increased power output and puff volume correspond with the formation of significantly higher amounts of •Oh in e-vapor due to elevated coil temperature and oxygen supply.
* Vegetable glycerin (VG) e-liquids generated higher •Oh levels than propylene glycol (PG) e-liquids, as did flavored e-liquids relative to nonflavored e-liquids.
* E-vapor in combination with ascorbic acid, which is an abundant biological molecule in human epithelial lining fluid, can also induce •Oh formation.
* The dose of radical per puff associated with e-cigarette vaping was 10-1000 times lower than the reported dose generated by cigarette smoking. however, the daily average •Oh dose can be comparable to that from cigarette smoking depending on vaping patterns.
* The safe range of e-cigarette power output and vaping frequency needs to be assessed, communicated, and regulated to protect public health, especially for e-cigarette users who use VG-based flavored e-cigarettes at higher power output settings.
* Popular use of flavored e-liquids might increase e-vapor •Oh exposures and result in potential health problems.
* Coexisting environmental exposures, such as airborne particulate matter, might further elevate oxidative stress in e-cigarette users.
Main Message:
The study suggests that e-cigarette users who use VG-based flavored e-cigarettes at higher power output settings may be at increased risk for •Oh exposures and related health consequences such as asthma and chronic obstructive pulmonary disease. The study highlights the need for further research on the health impacts of e-cigarette use, especially in the context of real-world vaping patterns. The study also underscores the importance of regulatory measures to protect public health, such as limiting the power output and nicotine content of e-cigarettes and restricting the use of flavored e-liquids.
Citation
Son Y, Mishin V, Laskin JD, et al. hydroxyl Radicals in E-Cigarette Vapor and E-Vapor Oxidative Potentials under Different Vaping Patterns. Chem Res Toxicol. 2019;32:1087-1095. doi:10.1021/acs.chemrestox.8b00400
