Study links youth vaping to increased metal exposure, raising public health concerns

By Pooja Toshniwal PahariaReviewed by Lily Ramsey, LLMApr 29 2024

In a recent study published in BMJ Tob Control, researchers investigated factors associated with urinary biomarkers of metal exposure from e-cigarettes among United States (US) adolescents.

Study: Biomarkers of metal exposure in adolescent ecigarette users: correlations with vaping frequency and flavouring. Image Credit: Yarrrrrbright/Shutterstock.com

Background

E-cigarettes have become the predominant route of nicotine intake among US teens, with their use expanding dramatically.

These e-cigarettes are sold in various flavors and include potentially dangerous chemicals, including metals. Metal concentrations in e-cigarette aerosol formulations and liquids are frequent, making youth vaping a grave public health risk.

Metals ingested via tobacco and e-cigarette usage can cause systemic damage, especially throughout childhood and adolescence.

Chronic low-level lead exposure has a considerable impact on cardiovascular and cognitive consequences. Cadmium exposure raises the incidence of osteoporosis and serves as a significant carcinogen via a variety of biochemical processes.

Chronic low-level lead exposure hurts the cardiovascular and renal systems, cognitive and mental development, and both sexes' fertility. Uranium exposure can induce local cytotoxic effects, and renal tubular toxicity is particularly harmful.

About the study

In the present study, researchers analyzed metal exposure among teenage e-cigarette users, investigating correlations between metal concentrations and vaping frequency and flavor.

The researchers analyzed the Population Assessment of Tobacco and Health (PATH) study's fifth wave data, which was conducted between December 2018 and November 2019, and included 200 United States adolescents aged between 13 and 17 years.

Using mass spectrometry, they analyzed urinary exposure to uranium, cadmium, and lead by vaping frequency and flavor type. The detection limits for uranium, lead, and cadmium were 0.0024 µg/L, 0.022 µg/L, and 0.055 µg/L, respectively.

The team classified participants reporting e-cigarette use ≥1.0 days in the previous month as current e-cigarette users. They divided vaping frequencies as frequent (>20 days), intermittent (six to <20 days), and occasional (one to five days) within the previous month, and flavor types as mint/menthol, sweet (such as candy, chocolate, and desserts), and fruit.

They collected urinary samples from the fourth PATH wave participants, excluding those under nicotine replacement treatment in the previous three days and those with creatinine values ≤10.0 mg/dL or above 370 mg/dL.

The researchers also excluded individuals using other forms of tobacco (i.e., cigars, cigarettes, hookah, pipe, bidi, smokeless tobacco, or kretek), e-cigarette non-users, and users of e-cigarettes not containing nicotine.

They used multivariate linear regressions and geometric mean ratios (GMR) for analysis, adjusted for second-hand tobacco exposure, e-cigarette device type, age, sex, race, ethnicity, and household income.

Results

Among the participants (median age, 16 years, 63% female), 65 used occasionally, 45 used intermittently, and 81 used frequently.

The mean number of daily puffs showed exponential increases in vaping frequencies (0.90 puffs, 7.90 puffs, and 27 puffs for occasional use, intermittent use, and frequent use, respectively). The researchers noted that 33% preferred mint/menthol, 50% fruity, and 15% preferred sweet-based flavors.

Intermittent (0.2 ng/mg of creatinine) users and frequent e-cigarette users (0.2 ng/mg of creatinine) showed higher urinary lead concentrations compared to those who used e-cigarettes occasionally (0.2 ng/mg of creatinine).

Intermittent users showed higher urinary lead concentrations compared to occasional e-cigarette users (GMR, 1.4). Similarly, frequent e-cigarette users also showed higher urine lead levels than occasional users (GMR, 1.3).

Adolescents using e-cigarettes frequently also showed higher urinary uranium concentrations than those using e-cigarettes occasionally (0.0090 ng versus 0.0050 ng per mg of creatinine, GMR, 2.3).

Sweet flavor preferers showed higher uranium concentrations than those preferring mint/menthol flavors (0.0090 ng versus 0.0050 ng per mg of creatinine, GMR 1.9).

Conclusions

The study findings showed that early-life vaping increases the chance of metal exposure, which may damage organ development and alter brain function. Frequent and intermittent users reported higher lead and uranium levels in their urine compared to occasional users.

Sweet-flavor vapers had nearly double the amount of uranium that menthol or mint users did. The results are concerning since a considerable number of teenage vapers use candy-flavored e-cigarettes, which might reduce the unpleasant effects of nicotine while increasing its rewarding effects, resulting in increased brain cue responsiveness.

The study emphasizes the significance of enacting vaping legislation and developing focused preventative efforts for teenagers.

Future research with bigger sample sizes might consider regional differences and metal concentrations in e-cigarette aerosol forms or e-liquids as contaminants or byproducts.

Additional studies might reveal the particular sources and mechanisms of uranium exposure. Vaping regulations should protect young people from addiction and exposure to metals.