Teen use of marijuana remains high, and vaping appears to be one reason, a new US survey shows. One in 10 high school seniors said they'd vaped marijuana at least once in the past year. It was the first time the annual survey asked about marijuana vaping, and "it's much higher than I expected," said Richard Miech, the University of Michigan researcher who led the study. For years, teen marijuana use in the US has been seen as relatively flat. Some experts have been expecting it to rise as states loosened marijuana laws, more adults used it, and fewer kids considered marijuana harmful. This year's survey—which included about 45,000 students in grades eight, 10, and 12 in schools nationwide—showed marijuana use was up overall about 1%, with nearly a quarter saying they'd vaped, smoked, or eaten marijuana in the previous year, per the AP.
Vaporizers, including e-cigarettes, are used with an assortment of liquids, such as oils with the active ingredients of marijuana; the oil is heated to create a vapor that's inhaled. "They're extremely discreet and they're very convenient" and aren't as messy or smelly as traditional joints, the owner of a Washington state marijuana shop said. Even in states that allow recreational marijuana use, it's illegal to sell weed to anyone younger than 21, and federal law prohibits sale of e-cigarettes to minors. But survey data suggests many teens are able to get the supplies to vape marijuana, often by ordering online. Experts say vaping marijuana is probably less harmful to the lungs than smoking joints, though they know less about its long-term effects and worry about its potency. Another survey find: About 5% of teens said they'd smoked cigarettes in the last 30 days, compared with nearly 15% who said they'd used pot.