Teen use of marijuana remains high and vaping appears to be one reason, a new U.S. survey shows. One in 10 high school seniors said they had 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 leads the study, the Associated Press reports. For years, teen marijuana use in the U.S. has been seen as relatively flat. Some experts have expected it to rise as states loosened marijuana laws, more adults used it and fewer kids considered marijuana harmful. This year’s survey showed marijuana use was up overall about 1 percent, with nearly a quarter saying they’d vaped, smoked or eaten marijuana in the previous year. Included in the survey: about 45,000 students in grades 8, 10 and 12.
Marijuana use was significantly higher than cigarette smoking. About 5 percent of teens said they’d smoked in the last 30 days, compared to nearly 15 percent who said they’d used marijuana. The survey found that the use of cocaine, heroin and other illicit drugs continues to decline overall, to the lowest levels seen in the 43 years of the survey. Vaporizers, including electronic cigarettes, are used with a wide assortment of liquids, including oils that contain the active ingredients of marijuana. 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. Dr. Nora Volkow, director of the National Institute on Drug Abuse, which funds the Michigan study, said that clearly, marijuana use isn’t declining and that’s a problem.