By Brian Coon, MA, LCAS, CCS, MAC with Becky Shipkosky

Back in 2023, Mark Salazar saw his friend smoking a disposable vape pod. This was his first exposure to e-cigarette products, and he was curious about it. Salazar happens to be a Ph.D.-candidate in pharmacology and toxicology at the University of California Davis, and he had a hunch there might be something of interest inside.

He took the device into the lab and tested it for metals. The results initially made him think his instrument was broken.

Over the next couple of years, Salazar and colleagues thoroughly analyzed metal and metalloid content in three popular disposables. They found that all three products leach lead, nickel, chromium, antimony, copper, and zinc at levels that “exceed acceptable non-cancer and cancer risk thresholds” for these elements (Salazar et al., 2025).

The disposable pods featured in Salazar’s study, published in July 2025, appear to emit more such toxins than earlier e-cigarette products, other disposable e-cigarettes, and traditional cigarettes. Meanwhile, disposable pods are the most popular type of vape device, and two of the three in the study are among the most popular with youth.

Vaping is a smokeless method of using nicotine, the toxic and addictive alkaloid found in tobacco. A vape device, or e-cigarette, consists of a battery, a metal heating element and a reservoir of carrier liquid. Additionally, a wick delivers the liquid to the heating element, and a firing mechanism delivers aerosol through a mouthpiece to be inhaled by the user.

To place vaping into context: it has emerged over the past two decades as an alternative to smoking, a tech-savvy substance delivery system, and a stealth-use product. It has been worryingly popular among teens and young adults. While just 6.5% of adults and 5.9% of teens in the U.S. report regular e-cigarette use (Vahratian et al., 2025), recent polling data, plus prevalence data in regions where the products were available just one to three years earlier, offer a sense of where we may be headed.

As so many products have, e-cigarettes became widely available to consumers long before the health impact was well understood. It still isn’t. Gaps in knowledge are commonly filled with optimistic assumptions, but as Carl Sagan pointed out: Absence of evidence is not evidence of absence.

We know that vape products contain dozens of chemicals, compared to 6500–7000 present in conventional cigarettes (Margham, 2010). We do not........

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