Disposable e-cigarettes more toxic than traditional cigarettes
High levels of lead, other hazardous metals found in e-cigarettes popular with teens
image:
UC Davis Ph.D. candidate Mark Salazar, left, holds a disposable vape pod in the lab with Brett Poulin, a UC Davis assistant professor of environmental toxicology.
view moreCredit: Kat Kerlin, UC Davis
They may look like travel shampoo bottles and smell like bubblegum, but after a few hundred puffs, some disposable, electronic cigarettes and vape pods release higher amounts of toxic metals than older e-cigarettes and traditional cigarettes, according to a study from the University of California, Davis. For example, one of the disposable e-cigarettes studied released more lead during a day’s use than nearly 20 packs of traditional cigarettes.
The study, published June 25 in the journal ACS Central Science, noted that although most disposable e-cigarettes are illegal in the United States, they remain widely available. Most consumers of disposable e-cigarettes are teens or young adults, who are also highly susceptible to lead exposure. Inhaling certain metals can increase a person’s risk of cancer, respiratory disease and nerve damage.
“Our study highlights the hidden risk of these new and popular disposable electronic cigarettes — with hazardous levels of neurotoxic lead and carcinogenic nickel and antimony — which stresses the need for urgency in enforcement,” said senior author Brett Poulin, an assistant professor in the UC Davis Department of Environmental Toxicology. “These risks are not just worse than other e-cigarettes but worse in some cases than traditional cigarettes.”
‘What are you smoking?’
First author Mark Salazar, a Ph.D. candidate in Poulin’s lab, first saw a disposable vape pod when he was visiting a friend. The pods are self-contained cartridges that hold a battery, e-liquid and heating coil. Salazar was curious: What, exactly, was his friend smoking? He brought the pod back to the lab at UC Davis and tested its vapor for metal concentrations.
“When I first saw the lead concentrations, they were so high I thought our instrument was broken,” Salazar said. “That sparked us into looking further into these disposables.”
The scientists analyzed the metal and metalloids inside seven types of disposable devices from three of the most popular brands. Using an instrument to activate the disposable e-cigarettes and heat the internal liquid, they created between 500 and 1,500 puffs for each device. They found:
- Some devices emitted surprisingly high concentrations of elements in the vapor, including antimony and lead.
- Levels of chromium, nickel and antimony increased as the number of puffs increased.
- Most of the disposable e-cigarettes tested released markedly higher amounts of metals and metalloids into vapors than earlier, refillable vapes.
The scientists then took apart the devices to trace the sources of the metals.
“We found that these disposable devices have toxins already present in the e-liquid, or they’re leaching quite extensively from their components into e-liquids and ultimately transferred to the smoke,” Salazar said.
Leaded bronze alloy components in some devices leached nickel and lead to the e-liquid. Nickel was also released from heating coils, and antimony was present in unused e-liquids at high levels, both of which increase the risk of cancer.
Understudied health risks
The researchers also assessed the health risk for daily users. Vapors from three of the devices had nickel levels and two devices had antimony levels that exceeded cancer risk limits. Vapors from four of the devices had nickel and lead emissions that surpassed health-risk thresholds for illnesses besides cancer, such as neurological damage and respiratory diseases.
While the researchers tested only three of the nearly 100 disposable e-cigarette brands on the market, they say this initial work prompts concern given the popularity of disposable e-cigarettes, especially among adolescents.
The market is also outpacing science. Few studies of the relatively new devices are available, leaving consumers and regulators largely uninformed. The work underscores the need to enforce regulations around illegal e-cigarettes while continuing research to reveal the extent of the problem and its public health implications.
The study’s coauthors include Lalima Saini, Tran Nguyen, Kent Pinkerton, Amy Madi and Austin Cole of UC Davis.
The research was supported with funding from the UC Tobacco-Related Disease Research Program, the National Institute of Environmental Health Sciences T32 training program, and the University of California Agricultural Experiment Station.
Ph.D. candidate Mark Salazar holds a disposable vape pod in the lab at UC Davis, where he found high levels of metals, including lead, in the devices especially popular with teens.
Ph.D. candidate Mark Salazar, left, holds a disposable vape pod in the lab at UC Davis, where he found high levels of metals, including lead, in the devices especially popular with teens.
Mark Salazar of UC Davis opens a disposable e-cigarette, or vape pod, to show its internal components, including a metal coil battery and e-liquid. These components were found in some devices to leach hazardous metals into the inhaled vapor.
Credit
Kat Kerlin/UC Davis
Journal
ACS Central Science
Method of Research
Observational study
Article Title
Elevated toxic element emissions from popular disposable e-cigarettes: sources, life cycle, and health risks
Article Publication Date
25-Jun-2025
Metals found in disposable e-cigarette vapor could pose health risks
Brightly colored inexpensive and disposable electronic cigarettes and vapes continue to gain popularity. These devices turn flavored nicotine-containing liquid into a vapor that people inhale over hundreds or thousands of puffs — commonly called vaping. Researchers report in ACS Central Science that after a few hundred puffs, some disposable vaping devices released higher amounts of metals and metalloids than older refillable e-cigarettes and traditional cigarettes, thereby raising a user’s risk of health problems.
“Our study highlights the hidden risk of these new and popular disposable electronic cigarettes — with hazardous levels of neurotoxic lead and carcinogenic nickel and antimony — which stresses the need for urgency in enforcement,” says Brett Poulin, the corresponding author of the study from the University of California, Davis.
Studies on early generations of refillable e-cigarettes (e.g., refillable pens, box mods and pods) found that their heating components could release metals such as chromium and nickel ions into the internal liquid that then becomes the vapor people breathe. Inhaling certain metals and metalloids is potentially harmful, increasing a person’s risk of cancer, respiratory disease and nerve damage.
Although marketing of most disposable e-cigarettes is not authorized by the U.S. Food and Drug Administration, the devices remain widely available. In the past few years, disposable e-cigarette sales have overtaken sales of older refillable vapes, but little is known about the elemental composition of vapors from the newer devices. So, Poulin and colleagues assessed popular disposable e-cigarette brands to evaluate the potential health risks they could pose to a user.
The researchers first identified the metal and metalloids inside seven disposable devices from three brands, comparing liquids with light and heavy levels of flavoring. The original unused liquids had low levels of ionic metals and metalloids, though some devices had surprisingly high levels of lead and antimony. The team traced the source of lead to leaded copper alloys used for non-heating components, which leach into the e-liquid. Antimony did not have a definable source.
Then they activated the disposable e-cigarettes, which heated the internal liquid and created between 500 and 1,500 puffs for each device. Analyses of the vapors determined that:
- The levels of ionic metals and metalloids including chromium, nickel, and antimony increased as the number of puffs increased, whereas concentrations of ionic zinc, copper, and lead were elevated at the start, and each device had different emissions.
- Compared with previous studies, most of the tested disposable e-cigarettes released higher amounts of metals and metalloids into vapors than older refillable vapes.
- One of the disposable e-cigarettes studied released more lead during a day’s use than nearly 20 packs of traditional cigarettes.
The researchers next assessed the health risk faced by a daily user of these devices. For two of the disposable vapes, the team collected toxicity information for chromium and antimony, substances that have non-toxic and carcinogenic forms. Only the non-toxic form of chromium, Cr(III), was present, but a mixture was observed between the less toxic form of antimony, Sb(V), and the carcinogenic form, Sb(III), in the vapors. However, nickel levels in vapors from three devices and Sb(III) levels in vapors from two devices exceeded cancer risk limits. The vapors from four of the devices had nickel and lead emissions that surpassed health risk thresholds for diseases other than cancer.
The researchers tested only three of the nearly 100 disposable e-cigarette brands available on store shelves. They say the results are concerning because of the current popularity and extensive use of disposable e-cigarette products, especially among adolescents and young adults.
The authors acknowledge support from the University of California Tobacco-Related Disease Research Program, the National Institute of Environmental Health Sciences T32 training program, and the California Agricultural Experiment Station.
The paper’s abstract will be available on June 25 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acscentsci.5c00641
###
The American Chemical Society (ACS) is a nonprofit organization founded in 1876 and chartered by the U.S. Congress. ACS is committed to improving all lives through the transforming power of chemistry. Its mission is to advance scientific knowledge, empower a global community and champion scientific integrity, and its vision is a world built on science. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.
Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.
Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.
Follow us: Facebook | LinkedIn | Instagram
Journal
ACS Central Science
Article Title
“Elevated Toxic Element Emissions from Popular Disposable E‑Cigarettes: Sources, Life Cycle, and Health Risks”
Article Publication Date
25-Jun-2025
No comments:
Post a Comment