One out of 10 American high school students used electronic cigarettes in 2012, along with nearly 3% of middle school students, according to a new federal report. That's about double the rate of e-cigarette use in 2011 and translates into 1.78 million children and teens who have tried the battery-powered devices.
The sharp increase has public health experts worried. Electronic cigarettes contain the addictive chemical nicotine and traces of cancer-causing compounds called nitrosamines. The safety profile of the devices has not been fully studied, according to warnings from the Food and Drug Administration.