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

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.

Cigarette Smoking Trajectories in Adult Former Smokers Using the JUUL System.

Objective: In this study, we assessed cigarette smoking over 12 months among adult former smokers who newly purchased a JUUL Starter Kit (JSK). Methods: Prevalence of past 30-day smoking and factors associated with smoking were assessed among adult (age ≥ 21) former established smokers, stratified as recent (quitting ≤ 12 months) and long-term quitters (> 12 months), who purchased a JSK and completed ≥ 1 of 6 follow-up assessments (N = 4786). Results: Recent quitters had higher rates (16.6%-19.9%) of past 30-day smoking than long-term quitters (6.4%-9.2%) across the 12-month period; smoking prevalence did not significantly increase over time in either subgroup. Few participants (6.5% of recent quitters, 2.8% of long-term quitters) reported smoking at both 9 and 12 months, a pattern that might indicate persistent smoking. Past 30-day JUUL use remained high (≥ 87%) across the 12 months. Participants who used JUUL more frequently were less likely to smoke. Conclusions: Among former smokers who purchased JUUL, prevalence rates of smoking were low and stable across the 12-month period, suggesting there was not a growing cohort of former smokers resuming smoking. Smoking was more common in recent quitters than long-term quitters. Greater use of JUUL was associated with reduced odds of smoking resumption.

Smoking Trajectories of Adult Never Smokers 12 Months after First Purchase of a JUUL Starter Kit.

Objectives: We assessed adult never smokers' trajectories of smoking over 12 months after a first-time JUUL Starter Kit (JSK) purchase. Methods: Adult (≥ 21) never smokers (N = 3853) who purchased a JSK were recruited into an observational naturalistic study. Analyses distinguished those who had previously used ENDS (NS+E, N = 2848) from those who had not (NS-NE, N = 1005). Participants were invited to complete follow-up assessments at 1, 2, 3, 6, 9, and 12 months. "Smoking" was defined as any past-30-day smoking ("even a puff"). Results: Past-30-day smoking was reported by 5.01% of NS+E at month one, and 7.56% at month 12; for NS-NE, these were 10.23% and 12.35%. In both groups, < 5% reported smoking at both 9 and 12 months. Across follow-ups, 25%-49% of those reporting having smoked then said they were now smoking "not at all"; the remainder reported low frequency (10-12 days-per-month) and quantity (2-4 cigarettes-per-day) of smoking. Past-30-day use of JUUL remained at ≥ 80% across follow-ups. Each additional day-per-month of JUUL use decreased the odds of smoking by 1%. Conclusions: Some adult never smokers who purchased a JSK reported smoking during the suceeding year; smoking was light and intermittent. Participants who used JUUL more frequently were less likely to smoke.