Biomarkers of toxicant exposure among youth in Canada, England and the United States who vape and/or smoke tobacco or do neither.

Abstract

Background: Few studies examine biomarkers of exposure to vaping and tobacco products among youth. We compared biomarkers for toxicants between youth who vape, smoke, 'dual-use', or neither.

Methods: Participants aged 16-19 in Canada, England, and the United States (US) completed surveys and self-collected urine samples between September 2019 and January 2022 (N=364). Urine was tested for metabolites of tobacco-specific nitrosamine NNK and six volatile organic compounds (VOCs). Regression models examined differences in biomarker concentrations by past-week tobacco smoking and vaping, adjusting for creatinine, age, sex, country, and cannabis use.

Results: Compared to no vaping/smoking, exclusive vaping was associated with similar exposure to acrolein and acrylonitrile, but higher exposure to toluene (p=.04) and acrylamide (p=.034, only in sensitivity analysis using past-24-hour measure). Compared to dual-use or exclusive smoking, exclusive vaping was associated with lower exposure to NNK, acrolein, acrylamide, and acrylonitrile (p≤.01), but higher toluene exposure than dual use (p=0.012). Exposure was similar for dual-use and exclusive smoking. Benzene and xylene biomarkers were detected in <5% and not compared. Among those smoking, NNK exposure was higher in the US (geometric mean=25.4pg/mg creatinine) versus Canada (16.1pg/mg; p=0.006) and England (14.1pg/mg; p=0.018).

Conclusions: Youth exclusively vaping had similar exposure as no vaping/smoking except for two VOCs, and lower exposure than smoking or dual use except toluene. Higher NNK levels among US youth who smoke likely reflect differences in tobacco blend.

Impact: Findings are generally consistent with literature indicating lower toxicant exposure from vaping versus smoking, but elevated exposure versus no use for some.