Smoking out e-cigarettes

Introduced in the United States two years ago, electronic cigarettes are no longer a novelty item but a popular option for many smokers — especially those who want to quit. Inhaling on the cigarette-shaped device activates a built-in battery, which heats up a mixture of water, nicotine and propylene glycol to give the “smoker” a vapor hit of the addictive substance found in cigarettes — but without the smoke. It even lights up at the other end, mimicking the tip of a cigarette. E-cigarettes ar