Comparison of Systemic Exposure to Toxic and/or Carcinogenic Volatile Organic Compounds (VOC) during Vaping, Smoking, and abstention.

Introduction:
This text discusses the results of a cross-over study that aimed to assess the exposure of e-cigarette users to toxic and/or carcinogenic volatile organic compounds (VOCs) compared to cigarette smokers and non-smokers. The study measured urinary biomarkers of VOCs in participants who used e-cigarettes only, cigarettes only, and had a period of enforced nicotine and tobacco product abstention.

Key Points:

* The study found that e-cigarette users were exposed to lower levels of toxic VOCs compared to cigarette smokers, supporting the harm reduction potential of e-cigarettes among smokers.
* however, some e-cigarettes potentially expose users to VOCs such as acrylamide, benzene, and propylene oxide, and may pose health risks to nonsmoking users.
* The study found that within-subject concentrations of metabolites of acrylamide, benzene, and propylene oxide were higher in participants who used e-cigarettes during the second arm, indicating a potential carryover effect on biomarker levels from smoking cigarettes.
* The 1,3-butadiene metabolite (MhBMa-3) and the propylene oxide metabolite (2-hPMa) were significantly different across e-cigarette devices, with higher levels in variable-power tank users.
* The correlation between plasma nicotine aUC and 2-hPMa (propylene oxide) was small and statistically significant for e-cigarette use.
* The study found that during e-cigarette use, most participants had higher levels of aaMa (acrylamide), PMa (benzene), and 2-hPMa (propylene oxide) compared to abstention.
* The study found that users of variable-power e-cigarettes had elevated excretion of the propylene oxide metabolite (2-hPMa) compared with users of other types of e-cigarettes.

Main Message:
The study highlights the potential harm reduction benefits of e-cigarettes for smokers, but also the need for regulation to minimize the risks to nonsmoking users. The study found that some e-cigarettes expose users to toxic VOCs such as acrylamide, benzene, and propylene oxide, and that certain device types and flavors may contribute to higher exposure. The study suggests that regulation of e-cigarettes must include a balanced approach to maximize their potential for harm reduction among adult smokers and minimize their risk to nonsmoking users, including minimizing exposure to toxic VOCs.

St helen G, Liakoni E, Nardone N, addo N, Jacob P, Benowitz NL. Comparison of Systemic Exposure to Toxic and/or Carcinogenic Volatile Organic Compounds (VOC) during Vaping, Smoking, and abstention. Cancer prevention research (Philadelphia, Pa). 2020;13(2):153-162. doi:10.1158/1940-6207.CaPR-19-0356