Metals in Cannabis Vaporizer Aerosols: Sources, Possible Mechanisms, and Exposure Profiles

In recent years, cannabis vaporizer cartridges have increased in popularity and availability, and there are concerns regarding exposure to heavy-metal compounds from their use. The physical components of the cartridge devices themselves have been implicated as a potential source of metal exposure, but it is not known if these metals migrate into the inhalable vapor. This study analyzes the components of vaporizer cartridges for 10 different metals and also collects aerosol mixtures from 13 randomly purchased commercially available cannabis cartridges from Washington State to compare their elemental profiles. Results indicate that chromium, copper, nickel, as well as smaller amounts of lead, manganese, and tin migrate into the cannabis oil and inhaled vapor phase, resulting in a possible acute intake of an amount of inhaled metals above the regulatory standard of multiple governmental bodies. Noncartridge heating methods of cannabis flower and concentrate were compared, and results indicate that the heating device itself is a source of metal contamination. As safety and compliance testing regulations evolve, it will be important to include more than the standard As, Cd, Hg, and Pb to the list of regulated metals.