What causes popcorn lung? Short answer: we don’t know. That should terrify you. Short guess: the added aldehydes. Longer answer: Most states are scrambling to just identify e-cigarettes, to decide on when kids should be able to get them, and to regulate them in some way. It’s the Wild West out there, with ages anywhere from 18–21, and many states not classifying vaping in the same way as tobacco use. [1] A cynical person might be suspicious that vaping is an end run by certain manufacturers to entice and addict more young smokers. In my blog post on popcorn lung I connect the dots and - no surprise - vaping is funded and owned by big tobacco. [2] The two solvents most commonly used in vaping, PG and glycerine, are relatively nontoxic, but the flavoring agents they are often combined with can be extremely toxic. We have almost no regulation of these, as many are considered safe for eating. But the chemistry changes when you vaporize something. One study found “detectable leve