Comparison of biomarkers of exposure among US adult smokers, users of electronic nicotine delivery systems, dual users and nonusers, 2018–2019

Abstract

The harm caused by cigarette smoking is overwhelmingly due to byproducts of tobacco combustion. Electronic Nicotine Delivery Systems (ENDS) provide nicotine to users without combustion, and may support tobacco harm reduction among cigarette smokers who would not otherwise quit in the near term. Analyses of Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study compared biomarkers of exposure (BOE) levels for nicotine, 3 metals, 2 tobacco-specific nitrosamines and 14 smoking-related volatile organic compounds in 151 exclusive ENDS users, 1341 exclusive cigarette smokers, 115 dual users (cigarettes and ENDS), and 1846 past 30-day nonusers of tobacco, adjusting for demographics. Nicotine exposure in ENDS users and dual users did not significantly differ from smokers. Among ENDS users, 16 of 18 other BOEs were significantly lower than smokers’; 9 BOEs were not significantly different from nonusers. Among dual users smoking < 10 cigarettes/day, 15 of 18 non-nicotine BOEs were significantly lower than smokers’, whereas in dual users smoking ≥ 10 cigarettes per day none of the BOEs significantly differed from smokers’. In this representative sample of US adults, exclusive use of ENDS (vs. cigarette smoking) was associated with much lower exposures to many harmful chemicals associated with smoking-related disease. BOE levels in dual users were directly related to their cigarette consumption. These BOE data provide further evidence that ENDS expose users to substantially lower levels of toxicants than combustible cigarettes, confirming their potential for harm reduction.

Metal in biological samples from electronic cigarette users and those exposed to their second-hand aerosol: a narrative review

“…Nathan et al ( 17 ) analyzed data from adults of at least 21 years who provided their urine samples for the PATH Study Wave ( 5 ). Participants were categorized into four groups based on their past 30-day use of ENDS and cigarette smoking.…”

“…Higher urinary Pb and Cd concentrations were found in e-cigarette smokers than in non-smokers by Goniewicz et al ( 11 ) and Kaplan et al ( 16 ). Nathan et al ( 17 ) showed a significantly higher concentration of Cd, Pb, and U in smokers and ENDS users than non-users and dual exposure (cigarette smoke/ENDS) is associated with higher Cd levels and that there is an exposure–response relationship with the number of cigarettes per day. From the PATH Study Wave 1, Lizhnyak et al ( 12 ) also found significantly higher urinary Cd levels in those who frequently smoke and vape than in those who only vape.…”

Randomized trial assessing the effect of the JUUL system on switching away from cigarettes and smoking reduction among U.S. adults who smoke cigarettes.

“…There is concern that concurrent cigarette smoking and use of ENDS (dual use) may be more harmful than smoking or ENDS use alone, as dual users may be exposed to toxicants from both cigarettes and ENDS (Coleman et al, 2022). However, data from studies that have evaluated biomarkers of exposure show that cigarette smoking is the primary driver of toxicant exposure among dual users (Holt et al, 2023; Majeed et al, 2020; Smith et al, 2021), and that if dual use is accompanied by substantial reductions in cigarette consumption it results in reduced exposure to toxicants known to be associated with smoking-induced disease (Anic et al, 2022; Cohen et al, 2021; D’Ruiz et al, 2016; Holt et al, 2023; Pulvers et al, 2020). Additionally, data from observational longitudinal studies suggest that dual use is often a transitional state on a pathway to complete switching (Martinez-Loredo et al, 2022; Selya et al, 2021).…”

Use of electronic nicotine delivery systems and cigarette smoking—Add-on vs. displacement dual use

“…The authors concluded that the frequency of cigarette use among those consuming both products was positively correlated with nicotine and toxicant exposure ( 15 ). A study funded by Juul labs (an e-cigarette company) using the same PATH Study, but data collected in 2018/19, compared dual users who smoked <10 cigarettes per day (“displacement dual users”) to those who smoked at least 10 cigarettes per day (“add-on users”) ( 16 ). Toxicant levels of displacement dual users were lower than those of add-on users, while the levels of add-on users were comparable to exclusive cigarette smokers ( 16 ).…”