Introduction
Introduction
Electronic cigarettes have become hugely popular in the United States since their U.S. introduction in 2007. The devices, which currently are not regulated by the federal government, deliver nicotine, the addictive substance in conventional cigarettes, through a vapor, without burned tobacco's toxic tar and smoke. Advocates say e-cigarettes could free users from addiction to deadly cigarettes. About 42 million American adults smoke tobacco, and half of the heaviest users will ...