Biomarkers of metal exposure in adolescent e-cigarette users: correlations with vaping frequency and flavouring.

BACKGROUND: Youth vaping poses a significant public health concern as metals have been detected in e-cigarette aerosols and liquids. This study investigated factors associated with biomarkers of metal exposure.

METHODS: Data were drawn from Wave 5 of the Population Assessment of Tobacco and Health (PATH) Study Youth Panel, a nationally representative sample of US adolescents aged 13-17 years. Urinary biomarkers of exposure to cadmium, lead, and uranium were assessed by vaping frequency (occasional (1-5 days), intermittent (6-19 days), and frequent (20+ days)) in the past 30 days and flavour type (menthol/mint, fruit, and sweet).

RESULTS: Among 200 exclusive e-cigarette users (median age 15.9 years, 62.9% female), 65 reported occasional use, 45 reported intermittent use, and 81 reported frequent use. The average number of recent puffs per day increased exponentially by vaping frequency (occasional: 0.9 puffs, intermittent: 7.9 puffs, frequent: 27.0 puffs; p=0.001). Both intermittent (0.21 ng/mg creatinine) and frequent users (0.20 ng/mg creatinine) had higher urine lead levels than occasional users (0.16 ng/mg creatinine). Frequent users also had higher urine uranium levels compared with occasional users (0.009 vs 0.005 ng/mg creatinine, p=0.0004). Overall, 33.0% of users preferred using menthol/mint flavours, 49.8% fruit flavours, and 15.3% sweet flavours. Sweet flavour users had higher uranium levels compared with menthol/mint users (0.009 vs 0.005 ng/mg creatinine, p=0.02).

CONCLUSIONS: Vaping in early life could increase the risk of exposure to metals, potentially harming brain and organ development. Regulations on vaping should safeguard the youth population against addiction and exposure to metals.