New Study Reveals High Levels of Toxic Metals in Disposable E-Cigarettes, Surpassing Traditional Cigarettes

Rising Concerns Over the Safety of Disposable E-Cigarettes

Over the past twenty years, electronic cigarettes—also known as e-cigarettes or vapes—have transformed the tobacco landscape, gaining remarkable popularity worldwide, especially among teenagers and young adults. Marketed as a modern and potentially safer alternative to traditional tobacco smoking, e-cigarettes have been positioned as a way to reduce harm from conventional cigarettes. However, new findings published on June 25 in the peer-reviewed journal ACS Central Science highlight that disposable e-cigarettes might pose more substantial health risks than previously understood.

New Evidence: Toxic Metal Exposure from Disposable Vapes

A research team led by scientists at the University of California, Davis, conducted in-depth chemical assessments of several leading disposable vape brands. The study specifically analyzed hazardous elements such as lead, chromium, antimony, and nickel—metals and metalloids known for their potential toxicity to the human body. These substances, when inhaled, are known to increase the risk of developing cancer, respiratory complications, and neurological disorders.

The key discovery is alarming: disposable vapes release toxic metals at concentrations far higher than those detected in both conventional cigarettes and refillable e-cigarettes. In one notable case, a single day’s usage of a specific disposable brand resulted in greater lead exposure than that from smoking nearly 20 packs of conventional cigarettes. Given the significant use of these products among adolescents, the authors urge immediate and robust regulatory intervention to minimize potential harm.

Expert Commentary Highlights Hidden Dangers

“These findings reveal that popular disposable e-cigarettes can expose users to dangerous levels of neurotoxic lead and carcinogenic nickel and antimony,” commented Brett Poulin, assistant professor of environmental toxicology and co-author of the study. “Such risks not only surpass those associated with other e-cigarettes but are, in some instances, even higher than traditional smoking.”

Regulatory Challenges and Ongoing Popularity Among Youth

Efforts by regulatory agencies like the U.S. Food and Drug Administration (FDA) have targeted the proliferation of flavored, disposable vapes, mainly due to rising concerns over underage access and associated health threats. Strategies have included issuing warning letters to major brands, imposing financial penalties, and blocking imports of unauthorized products, particularly from overseas manufacturers. Despite these measures, enforcement gaps have allowed a persistent rise in the availability and use of disposable e-cigarettes in the United States.

The 2025 National Youth Tobacco Survey conducted by the FDA highlights that disposable e-cigarettes now dominate youth tobacco usage, outpacing traditional and refillable vaping devices. Nearly 6% of middle and high school students reported current e-cigarette use, with disposable products accounting for more than half of these users. This trend underscores a critical need for more effective prevention and regulatory strategies.

Methodology: Evaluating Toxic Metals in Disposable Vape Products

While previous research has scrutinized the elemental makeup of refillable vape pens, this new study fills a crucial gap by analyzing the metallic content of disposable devices. The research team selected seven disposable vapes from three leading brands, incorporating both flavored and unflavored variants. Most of the devices contained nicotine, allowing for comparison between nicotine-containing and nicotine-free e-liquids—a factor hypothesized to affect metal concentrations in aerosol emissions.

Disposable vapes are constructed from a battery, a heating coil, and a nicotine or flavor solution (popularly called vape juice or e-liquid). When activated—either by a button or by direct inhalation—the coil heats the e-liquid and generates an aerosol for inhalation. Crucially, this process can leach metals from the heating element and internal components into the vapor, raising health concerns about inhaled toxins.

Researchers simulated usage by drawing 500 to 1,500 puffs per device under controlled conditions. Both unused e-liquids and generated aerosols were analyzed for metal content. The results revealed that hazardous metals such as antimony, lead, and nickel were either already present in unused vape juices or were introduced at concerning levels through sustained device use, especially as the number of puffs increased.

Key Findings: Aging Devices, Higher Metal Exposure

Lead author Mark Salazar, a doctoral candidate in environmental toxicology, noted, “Toxic substances either pre-exist in the e-liquid or are released in significant amounts from device components into the vapor, especially with prolonged use.” The study found that some e-liquids contained high concentrations of antimony before use, and device aging appeared to exacerbate metal leaching.

Additionally, heating coil degradation was found to be a primary source of nickel contamination. Some devices constructed with leaded bronze alloys leached both nickel and lead, posing a multifaceted risk to users. Aerosol samples from certain models exhibited metal concentrations that not only exceeded recommended cancer risk thresholds for nickel and antimony but also presented notable non-carcinogenic risks, such as nerve and lung damage, at levels surpassing established guidelines.

Implications for Public Health and Tobacco Policy

While the current study assessed only a subset of the nearly 100 disposable vape brands available in the U.S., the consistent findings of elevated toxic metal emissions point to a likely industry-wide issue. With youth uptake of disposable e-cigarettes continuing to climb, the research community stresses the necessity for expanded studies, more rigorous product testing, and heightened regulatory vigilance.

Despite regulatory initiatives, the popularity and accessibility of these products persist. The research team advocates for more comprehensive investigations into the chemical hazards of disposable vapes, emphasizing that these products represent an ongoing and potentially escalating public health challenge.

Conclusion

Emerging evidence suggests that disposable e-cigarettes may expose users, especially young people, to significantly higher levels of toxic metals and metalloids than either traditional cigarettes or refillable vape devices. This new research calls into question the perceived safety of disposable vapes and spotlights the urgent need for stronger regulatory action, enhanced surveillance, and independent scientific assessment. As disposable vape use continues to grow worldwide, understanding and mitigating their health risks should be a priority for policymakers, health professionals, and the broader scientific community.