Hey Mr. Green,

Is secondhand vapor from electronic cigarettes dangerous, and is “vaping” really as safe for users as has been insinuated?

—Eliot in Berkeley, California

About the only thing I can say with certainty about vaping is that it might reduce the number of polluting cigarette butts and filters flipped into the U.S. environment at the rate of 55,000 tons a year. Not much is known about e-cigarettes despite the fact that there are already more than 450 brands of them, officially known as Electronic Nicotine Delivery Systems (ENDS), whose ingredients have almost 8,000 different flavors.

The American Heart Association’s extensive review of ENDS research says that the few studies done so far indicate that vaporized nicotine is much less toxic than cigarette smoke, but that “the potential harm incurred by long-term use of these devices remains completely unknown.” The flavorings have been found to contain some harmful substances, and some e-cigs release bits of the metal, ceramic, and other material from which they’re made. Moreover, the organization warns, even without the carcinogens in smoke, nicotine by itself can increase heart rate and blood pressure, and is known to affect fetal development. So if you’re pregnant or have cardiac problems, don’t consider e-cigs to be a safe alternative to demon tobacco. Quit before you die or spawn a damaged kid.

The American Lung Association and the American Cancer Association have similar reservations about ENDS, while the American Physiological Society has documented short-term lung damage and inflammation from them. All these groups are calling for more research. The fact that three major tobacco companies, the original pushers, are buying up ENDS companies means we're unlikely to find out soon if the ends justify the ENDS.—Bob Schildgen