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.