Disposable vapes are more toxic than traditional vapes and release more heavy metals than cigarettes, according to a study.

Some vapes, or disposable e-cigarettes, although they look like travel-size shampoo bottles and smell like bubblegum, release higher amounts of toxic metals after a few puffs than rechargeable e-cigarettes and traditional cigarettes.

That's the conclusion of a study led by the University of California, Davis (United States) and published in the journal ACS Central Science .

More lead than 20 packs of cigarettes

The authors found, for example, that one of the disposable e-cigarettes studied released more lead during a day of use than nearly 20 packs of traditional cigarettes .

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The study notes that most disposable e-cigarette users are teenagers or young adults, who are also highly susceptible to lead exposure . Inhaling certain metals can increase the risk of cancer, respiratory diseases, and nerve damage.

"Our study highlights the hidden risks of these popular new disposable e-cigarettes , which contain dangerous levels of neurotoxic lead and carcinogenic nickel and antimony," said Brett Poulin, an assistant professor in the Department of Environmental Toxicology at the University of California, Davis. "These risks are not only worse than those of other e-cigarettes, but in some cases, even worse than those of traditional cigarettes."

Metalloids

Mark Salazar, a PhD candidate in Poulin's lab, first saw a disposable vape cartridge while visiting a friend. They are self-contained devices that contain a battery, e-liquid, and a heating element.

Salazar was curious about what exactly his friend was smoking. He took the cartridge to the lab and analyzed its vapor for metal concentrations.

"When I first saw the lead concentrations, they were so high that I thought our instrument was broken. That motivated us to investigate these disposables further," he adds.

Scientists analyzed the metals and metalloids present in seven types of disposable devices from three of the most popular brands. Using an instrument to activate the disposable e-cigarettes and heat the liquid inside, they generated between 500 and 1,500 puffs from each device.

They found that some devices emitted surprisingly high concentrations of elements in the vapor, including antimony and lead . In addition, the levels of chromium, nickel, and antimony increased as the number of puffs increased.

Most of the disposable e-cigarettes tested released significantly higher amounts of metals and metalloids into the vapor than previous refillable vaporizers.

The scientists then disassembled the devices to trace the sources of the metals. "We found that these disposable devices either have toxins already present in the e-liquid or that they largely leach from their components into the e-liquids and ultimately transfer into the smoke," Salazar emphasizes.

Leaded bronze alloy components in some devices released nickel and lead into the vaping liquid. Nickel was also released from heating elements, and antimony was found at elevated levels in unused vaping liquids, factors that increase the risk of cancer.

Little-studied risks

The researchers also assessed the health risks to everyday users. Vapors from three of the devices contained levels of nickel and two of antimony that exceeded cancer risk limits.

Similarly, the fumes from four of the devices emitted nickel and lead, exceeding the risk thresholds for diseases other than cancer, such as neurological damage and respiratory illnesses.

Although the researchers tested only three of the nearly 100 brands of disposable e-cigarettes on the market, they note that this initial work raises concerns, given the popularity of disposable e-cigarettes, especially among teens.

Few studies are available on these relatively new devices, leaving consumers and regulators uninformed. The work underscores the need to enforce regulations on illegal e-cigarettes , while continuing research to reveal the magnitude of the problem and its implications for public health.

References

Mark R. Salazar, Lalima Saini, Tran B. Nguyen, Kent E. Pinkerton, Amy K. Madl, Austin M. Cole, Brett A. Poulin. Elevated Toxic Element Emissions from Popular Disposable E-Cigarettes: Sources, Life Cycle, and Health Risks. ACS Central Science (2025). DOI: https://doi.org/10.1021/acscentsci.5c00641

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