yea, i made a reply about it earlier, lemme copy/paste.
Popcorn lung is a condition caused by diacetyl, a chemical that flavors stuff like microwave popcorn. It's okay to eat, but apparently very bad to inhale...Personally, I try to avoid the buttery flavors (found in a lot of the creamy desert flavors).
yea, the flavoring is where you'd introduce the most risk i think, so i think people should focus on that when making vaping decisions.