A multi-platform mass spectrometry study has traced toxic metals from e-cigarette aerosols into lung tissue after short-term exposure, highlighting the device itself as a potential source of inhaled metal contaminants.
The researchers designed the study as a device-to-tissue analytical workflow, linking total metal measurements in refillable e-liquid with aerosol speciation and elemental imaging of exposed lung tissue. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify metals in the e-liquid, while thermal desorption gas chromatography–ICP-MS examined metal-containing aerosol species and laser ablation ICP-MS/MS mapped deposition in murine lung sections.
“From a risk perspective, the findings reveal under-recognized hazards associated with vaping,” said lead researcher Dayanne Bordin, lecturer in analytical chemistry at the University of Technology Sydney, in the team’s press release. “Metal emissions and their biological effects are rarely incorporated into current safety assessments or public understanding.”
Using a refillable KangerTech device, the team detected several toxicologically relevant metals in the e-liquid, including aluminum, nickel, copper, arsenic, tin, mercury, and lead. Aerosol analysis revealed metal-containing chromatographic species associated with aluminum, nickel, copper, arsenic, bromine, tin, and mercury. Because complementary GC-MS and GC×GC-TOF-MS did not provide definitive molecular assignments, the authors treated the signals as metal-containing aerosol species rather than fully characterized organometallic compounds.
To test whether aerosol exposure led to tissue deposition, the researchers exposed mice to nicotine-containing e-cigarette aerosols at 8, 16, or 32 puffs twice daily for four days, alongside air-exposed controls. Elemental imaging of lung sections showed exposure-associated changes in metal distribution, including significantly elevated mean nickel concentrations and increased maximum lead concentrations. Copper and tin also showed focal accumulation patterns, while pulmonary iron concentrations were significantly reduced.
The elemental maps showed spatially uneven metal deposition, with some signals concentrated in specific lung regions. The authors suggest that these patterns may reflect differences in aerosol particle size, chemical form, deposition pathway, and clearance dynamics. “The metal profiles observed are consistent with emissions from heating coils and electrical components, identifying the device itself as a critical source of exposure,” said Bordin.
The authors caution that the short-term mouse model and single refillable device cannot capture the full range of human exposures or commercial products. Even so, they argue that the findings support routine testing of metal and metal-containing aerosol emissions from e-cigarette devices, particularly from heating coils and internal components.
Further studies will be needed to determine whether deposited metals persist in lung tissue, enter circulation, or contribute to respiratory effects.
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