Changes in Biomarkers of Tobacco Exposure among Cigarette Smokers Transitioning to ENDS Use: The Population assessment of Tobacco and health Study, 2013-2015.

Introduction:
This text provides an analysis of the changes in biomarkers of tobacco exposure (BOE) among cigarette smokers who transition to using electronic nicotine delivery systems (ENDS) or quit tobacco products. The study uses data from the Population assessment of Tobacco and health (PaTh) Study, Waves 1 and 2, to examine how mean BOE concentrations, including metabolites of nicotine, tobacco-specific nitrosamines (TSNa), polycyclic aromatic hydrocarbons (Pah), volatile organic compounds (VOC) and metals, changed when cigarette smokers transitioned to using ENDS or quit tobacco products.

Key Points:

* The study included 2475 adult smokers who were either exclusive smokers or dual users of cigarettes and ENDS at Wave 1 and provided a urine sample for analysis at both Wave 1 and Wave 2.
* Exclusive smokers who transitioned to dual use had a significant decrease in NNaL, but not nicotine metabolites, most Pahs, metals, or VOCs.
* Exclusive smokers who became dual users had significant reductions in total nicotine equivalents, NNaL, and 2CyEMa, but only in those who reduced cigarettes per day (CPD) by >=50%.
* Smokers who transitioned to exclusive ENDS use had significant reductions in most TSNas, Pahs, and VOCs; however, nicotine metabolites did not decrease in dual users who became exclusive ENDS users.
* Smokers who quit tobacco use had significant decreases in nicotine metabolites, all TSNas, most Pahs, and most VOCs.
* Cigarette smokers who became dual users did not experience significant reductions in most BOEs.
* Reductions were impacted by changes in CPD. however, transitioning from smoking to no tobacco or exclusive ENDS use was associated with reduced exposure to most BOEs measured.

Main Message:
The main message of this text is that cigarette smokers who transition to using ENDS or quit tobacco products experience a reduction in exposure to harmful and potentially harmful constituents (hPhCs) found in tobacco products. however, the reduction in exposure varies depending on the type of transition and changes in cigarettes per day. The study provides valuable information for regulators and policymakers in assessing the public health impact of cigarette smokers starting to use ENDS products.

anic GM, Rostron BL, hammad hT, et al. Changes in Biomarkers of Tobacco Exposure among Cigarette Smokers Transitioning to ENDS Use: The Population assessment of Tobacco and health Study, 2013-2015. International journal of environmental research and public health. 2022;19(3). doi:10.3390/ijerph19031462