By Emily Scheie

(WNS)–A new survey about teen substance abuse shows drug and alcohol use is down, but it’s been replaced by something health experts say could have long-term, as-yet unknown effects—e-cigarettes.

The Monitoring the Future survey has gathered information on students’ drug, alcohol, and cigarette use for 40 years. But for the first time, this year’s survey measured students’ use of e-cigarettes—battery-powered devices that produce a vapor usually containing nicotine. The results of the survey, released this month, show e-cigarettes are more than twice as common among certain ages as traditional cigarettes, causing concern over health risks and the possibility of losing ground in the struggle against teenage smoking.

The survey, funded by the National Institute on Drug Abuse and conducted by the University of Michigan, included more than 41,500 students in 377 secondary schools. On many fronts, the results reveal positive changes, including declines in binge drinking, abuse of prescription painkillers, and use of traditional cigarettes. Only 8 percent of students in 8th, 10th, and 12th grades combined reported smoking traditional cigarettes in the past 30 days, compared to 10 percent in 2013 and 28 percent in 1998.

But more than 8 percent of 8th grade students reported using an e-cigarette in the past month, compared to the 4 percent who smoked a traditional cigarette. Slightly more than 7 percent of high school sophomores used a traditional cigarette in the past month, but more than twice as many—slightly more than 16 percent—reported using an e-cigarette in the past 30 days.

The difference for 12th grade students was also significant but less dramatic. More than 13 percent said they’d smoked a traditional cigarette in the past month while just more than 17 percent said they’d used an e-cigarette.

The newness and appeal to younger crowds are some of the main concerns surrounding the e-cigarettes. Supporters say the devices, which lack the smoke and tobacco in traditional cigarettes, are a healthier alternative. But the Food and Drug Administration website on electronic cigarettes says the devices “have not been fully studied,” so consumers don’t yet know the full risks or benefits.

E-cigarettes come in many flavors, such as Cherry and Piña Colada, which some say make them more attractive to teens. The Centers for Disease Control and Prevention says nicotine can harm adolescents whose brains are still developing. But as of mid-December, according to the CDC, 10 states and the District of Columbia allowed selling electronic nicotine delivery systems (ENDS), such as e-cigarettes, to minors.

“We know e-cigarettes are not safe for youth,” said Tim McAfee, director of the CDC’s Office on Smoking and Health, in a statement released a few days before the Monitoring the Future survey results. Though he said the devices might benefit adult smokers if they use them as a “complete substitute” for all smoked tobacco, McAfee said youth and non-tobacco users should not use e-cigarettes since they might open the door to “other forms of tobacco use.”

Researchers say time will tell whether e-cigarettes are a gateway to traditional smoking. “We can’t give teens e-cigarettes and see if they progress to harder drugs of course,” said Richard Miech, a research professor from the University of Michigan, in a teleconference on the Monitoring the Future results. “So the best we can do is follow people who have used e-cigarettes and see what happens to them as they age.”

Schools across the country are responding to the rise of e-cigarettes by creating prohibitions against them. Some teachers are concerned because it’s hard to know exactly what’s in the e-cigarette a student is using. Cartridges can range from high-nicotine to nicotine-free, and it’s possible to make cartridges containing THC, the active ingredient in marijuana, without users emitting the telltale smell of marijuana smoke.

“If I am running a school or a house and I have a nose, I can tell if my kids are smoking pot,” Mark Kleiman, professor of public policy at the University of California, Los Angeles, told NPR,. “But if they’re using a vape pen, forget about it.”