[17] Youth also reported product flavoring as a top reason for using tobacco within the past 30 days (81.5% of youth who use e-cigarettes, 78.9% of youth who use hookah, 73.8% of youth who smoke cigars, 69.3% of youth who use smokeless tobacco, and 67.2% of youth who use snus)
These things haven't been around long enough and been studied
Wang Y, Yue X, Kiesewetter DO, Niu G, Teng G, Chen X (2014)
Nearly 2,000 ChemicalsSome Potentially HarmfulFound in Vaping Aerosols Researchers discover industrial chemicals, a pesticide and caffeine during analysis of popular vaping products When vaping first became popular, proponents were quick to claim it was safer than smoking cigarettes
Do cigarettes make you sleepy or awake