Biomarkers of Exposure to Tobacco-Related Toxicants among Adult Nicotine Pouch Users

Abstract Introduction Nicotine pouches (NPs) are an emerging nicotine delivery system. Understanding nicotine and toxicant exposure among NP users compared with users of other tobacco products and non-users is critical for informing public health strategies. Methods Data (n = 4527) were drawn from the Population Assessment of Tobacco and Health Study Wave 7 (2022–2023). Participants were classified into four mutually exclusive groups: non-tobacco users, exclusive NP users, exclusive e-cigarette users, and exclusive cigarette smokers. Geometric mean concentrations of biomarkers from urinary nicotine metabolites, minor tobacco alkaloids, and heavy metals were compared across groups using general linear model adjusted for demographics and current marijuana use. Results Despite having higher levels of nicotine metabolites than non-tobacco users (eg, cotinine, 2137.2 vs. 0.2 ng/mg creatinine, p < .0001), exclusive NP users showed no significant differences in levels of metals or minor tobacco alkaloids (p > .05). Exclusive NP users had comparable levels of nicotine metabolites to exclusive cigarette smokers (p > .05), but significantly higher concentrations of certain nicotine metabolites than exclusive e-cigarette users (eg, TNE-2: 27.3 vs. 7.0, p = .02). Meanwhile, exclusive NP users exhibited lower levels of anabasine (0.6 vs. 9.3 ng/mg creatinine, p < .0001), anatabine (0.4 vs. 14.7 ng/mg creatinine, p < .0001), and lead (0.2 vs. 0.4 ng/mg creatinine, p = .003) than exclusive cigarette smokers and lower levels of lead (p = .02) than exclusive e-cigarette users. Conclusions NP users have substantially elevated nicotine exposure without a corresponding rise in selected tobacco alkaloids or metals. Findings from objective biomarker measures could inform harm reduction strategies and shape regulatory policies concerning emerging nicotine products. Implications Nicotine pouches (NPs) are gaining popularity in the United States. The long-term health effects of nicotine pouch use remain unknown, and this national study offered early evidence into the scope of toxicant exposure associated with nicotine pouch use. Exclusive nicotine pouch users exhibited higher levels of nicotine metabolites but lower concentrations of anabasine and lead compared to cigarette smokers, indicating that NPs may serve as a potential harm-reduction strategy for combustible cigarette smokers. Findings from this study add to the current field of tobacco regulatory science and may inform future efforts to evaluate their effectiveness in smoking cessation or substitution.