Comparison of Urinary Biomarkers of Exposure in humans Using Electronic Cigarettes, Combustible Cigarettes, and Smokeless Tobacco.

Introduction:
This text provides an in-depth analysis of a study that compares the levels of urinary biomarkers of exposure in humans using electronic cigarettes, combustible cigarettes, and smokeless tobacco. The study aims to determine the extent of exposure to volatile organic compounds (VOCs) due to the use of these tobacco products.

Key Points:

* The study recruited 48 healthy tobacco users and 12 nontobacco users.
* Urine samples were collected at baseline and after using the assigned tobacco product for 3 hours.
* The study measured urinary metabolites of VOCs, nicotine, and tobacco alkaloids.
* Compared to nontobacco users, e-cigarette users had higher levels of urinary metabolites of xylene, N,N-dimethylformamide, and acrylonitrile after e-cigarette use.
* Smokers had significantly higher levels of metabolites of acrolein, crotonaldehyde, and 1,3-butadiene than users of other products or nontobacco users.
* The VOC metabolite levels in the smokeless tobacco group were comparable to those found in nonusers, with the exception of xylene metabolite-2-methylhippuric acid (2Mha), which was almost threefold higher than in nontobacco users.
* Occasional users of first generation e-cigarettes had lower levels of nicotine exposure than the users of combustible cigarettes.
* The absence of anatabine in the urine of e-cigarette users suggests that measuring urinary levels of this alkaloid may be useful in distinguishing between users of e-cigarettes and combustible cigarettes.

Main Message:
The study shows that smoking results in exposure to a range of VOCs at concentrations higher than those observed with other products, and first generation e-cigarette use is associated with elevated levels of N,N-dimethylformamide and xylene metabolites. however, the levels of most VOCs are lower in e-cigarettes and smokeless tobacco products compared to combustible cigarettes. These findings have implications for tobacco regulation and public health efforts to reduce tobacco-related harm.

Lorkiewicz P, Riggs DW, Keith RJ, et al. Comparison of Urinary Biomarkers of Exposure in humans Using Electronic Cigarettes, Combustible Cigarettes, and Smokeless Tobacco. Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco. 2019;21(9):1228-1238. doi:10.1093/ntr/nty089