The concentration of metals found in that study were below the legal limits for inhalational medicines. The type of vaping device studied was something called a

The concentration of metals found in that study were below the legal limits for inhalational medicines. The type of vaping device studied was something called a "cartomizer" of a design which is now broadly obsolete; these cartomizers feature heating elements with solder joints which remain immersed in the e-liquid solution, whereas more modern devices generally use a heating element comprising a single piece of stainless steel. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057987 https://journals.plos.org/plosone/article?id=10.1371/journal...