From 0 to 10 million: Vaping takes off in the U.S.

An employee of Irie Hawaii Smoke Shop in Hilo demonstrates a variety of devices and e-liquids for vaping. (HOLLYN JOHNSON/Tribune-Herald)
Puna resident Tim Michel demonstrates vapor from an electronic cigarette outside the county building in Hilo on Thursday. (Nancy Cook Lauer/West Hawaii Today)

Some experts have suggested that e-cigarettes can help wean people off regular cigarettes; others believe that they reinforce the smoking habit and increase the user’s exposure to nicotine.