“When I first saw the lead concentrations, they were so high I thought our instrument was broken…” Salazar and his colleagues discovered concentrations of toxic forms of metals like nickel, chromium, and antimony in most of the tested vapes. To quickly sum up what makes these metals bad: the type of nickel the researchers detected can cause lung and nasal cancer; chromium is also considered a carcinogen; and antimony can lead to heart and lung problems when inhaled as a dust and cause vomiting when swallowed.

Yikes. https://futurism.com/neoscope/vape-clouds-horrifying-chemicals