Heavy metals in vape aerosol come primarily from two sources: the heating coil (chromium, nickel, copper) and the e-liquid itself (lead, arsenic, from raw material contamination).
Key findings:
- Chromium and nickel are consistently found in vape aerosol, leached from the metal coil. Levels are generally lower than cigarette smoke but higher than clean air (Goniewicz et al., 2023)
- pH matters. Lower pH e-liquids (acidic, common with fruit flavors) increase metal leaching from coils. We explain how pH affects nicotine delivery and coil chemistry
- Coil age matters. Older, gunked-up coils produce more metal particles than fresh coils
- Power level matters. Higher wattage = higher coil temperature = more metal leaching
Practical tip: You can reduce heavy metal exposure by: (1) replacing coils regularly (don't wait for burnt taste), (2) using moderate power settings, (3) choosing devices with ceramic coils where available (though ceramic has its own concerns about silicate particles), and (4) avoiding extremely acidic e-liquids that accelerate coil degradation.
For comparison, cigarette smoke contains dramatically higher levels of heavy metals — including lead, cadmium, and arsenic — plus radioactive elements like polonium-210. Vaping reduces but does not eliminate metal exposure.
