Elevated Toxic Element Emissions from Popular Disposable E‑Cigarettes: Sources, Life Cycle, and Health Risks.

The rapidly evolving market of disposable e-cigarettes poses unknown health risks to adolescents and young adults. We report excessive emissions of toxic metallic elements in aerosols from flavored and "clear" versions of three popular products (Esco Bar, Flum Pebble, and ELF Bar), orders of magnitude higher in concentration than traditional cigarettes and other e-cigarettes. Heating coil elements (chromium (Cr), nickel (Ni)) likely leached into e-liquids and aerosols from coil degradation during use, increasing up to 1000-fold in concentration over the device life. In Esco Bar devices, high concentrations of lead (Pb, ≤175 ppm), Ni (≤38 ppm), copper (Cu, ≤546 ppm), and zinc (Zn, ≤462 ppm) were observed in both e-liquids and aerosols. We identified the illicit use of leaded bronze in nonheating device components in contact with e-liquid as the source of Pb. Elevated antimony (Sb) in Flum Pebble and Esco Bar samples had unknown origins. Analyses showed Cr was present as nontoxic Cr-(III), while Sb was a mixture of nontoxic Sb-(V) and carcinogenic Sb-(III). Risk assessments revealed cancer risks from Ni and Sb-(III) and noncancer toxicity risks from Pb and Ni exceeded safety thresholds. These findings highlight critical gaps in e-cigarette regulation, characterization, and enforcement, with implications for public health.