Exposure to Toxicants associated With Use and Transitions Between Cigarettes, e-Cigarettes, and No Tobacco.

Introduction:
This text provides an analysis of a longitudinal cohort study examining changes in urinary biomarkers of exposure to harmful and potentially harmful constituents (hPhCs) among adult tobacco users who transition between cigarettes, e-cigarettes, and no tobacco use. The study aimed to estimate national estimates for changes in a wide range of 55 urine biomarkers across 5 classes of hPhCs in association with transition patterns between cigarette and e-cigarette use from baseline to 1-year follow-up.

Key Points:

* The study used data from the Population assessment of Tobacco and health Study (PaTh) and focused on adult tobacco users who voluntarily provided biospecimens at two waves.
* Participants were divided into three mutually exclusive groups at baseline: exclusive cigarette smokers, exclusive e-cigarette users, and dual users.
* The study examined changes in 55 biomarkers of exposure (BOEs) to hPhCs, including nicotine metabolites, tobacco-specific nitrosamines (TSNas), metals, polycyclic aromatic hydrocarbons (Pahs), and volatile organic compounds (VOCs).
* The primary analysis selected a panel of 12 BOEs that are most relevant to the health effects of cigarette and e-cigarette use.
* Transitions from cigarettes or dual use to exclusive e-cigarette use or no tobacco use were associated with reduced exposure to TSNas, Pahs, and VOCs.
* Transitions from exclusive e-cigarette use to exclusive cigarette use or dual use were associated with increased exposure to BOEs.
* Transitioning between exclusive cigarette use and dual use was not associated with a decrease in levels of toxicant biomarkers in urine.

Main Message:
The findings of this study highlight the potential harm reduction associated with transitioning from exclusive cigarette use or dual use to exclusive e-cigarette use or no tobacco use. The results suggest that switching completely from combustible cigarettes to e-cigarettes may provide meaningful health benefits for current smokers. however, the study also emphasizes that transitioning to dual use of cigarettes and e-cigarettes is not associated with a decrease in levels of toxicant biomarkers in urine, suggesting that e-cigarettes may appeal to cigarette smokers as a complementary product instead of a replacement for combustible cigarettes. The results of this study may inform regulatory strategies and public health policies to guide tobacco users toward harm reduction transition patterns.

Dai h, Benowitz NL, achutan C, Farazi Pa, Degarege a, Khan aS. Exposure to Toxicants associated With Use and Transitions Between Cigarettes, e-Cigarettes, and No Tobacco. JaMa network open. 2022;5(2):1. doi:10.1001/jamanetworkopen.2021.47891