(CNN) Smoking isn't the only way teens are using cannabis. According to a study published Friday in the medical journal JAMA Network Open, they are also vaping it or using edibles.
The study surveyed 3,177 10th graders in southern California in 2015 and 1,077 reported ever using cannabis. It found that 61.7% of those who had used cannabis had tried at least two methods -- combustible, edible or vaporized cannabis.
Use of all three cannabis products was reported by 8.2% of those who'd used it.
"We found that cannabis use was highly prevalent, but what was interesting and new was that the majority of youth who had used cannabis in one form had not only used just one type of cannabis, but they used two or more different types of cannabis products," said Adam Leventhal, lead author of the study and director of the University of Southern California Health, Emotion and Addiction Laboratory.
Of those participants who had ever used cannabis, 31.3% had used combustible cannabis, 21.3% had used edibles and 10.5% had used vaporized cannabis. Those who had used cannabis in the past 30 days followed the same pattern.
"While use of the traditional smoked form of cannabis was still the most popular form, we did find a sizable portion of teens who had never smoked cannabis, but did report using edibles or vaporized," Leventhal said.
Among the 1,077 who had ever used any type of cannabis, 7.8% had never smoked it; 2.9% were exclusive vaporized cannabis users and 4.2% were exclusive edible users.
"Vaping is the newest and most substantial trend in adolescent cannabis use," Richard Meich, principal investigator at Monitoring the Future and professor at the Institute for Social Research at the University of Michigan, said via email. He was not involved with this study.
Previous research by Monitoring the Future found that in 2017 more than one in four US 12th graders had reported vaping cannabis in the past year.
"Adolescent cannabis use has been pretty steady the past couple of years," Meich said, "so it doesn't appear that these new alternatives are drawing in new cannabis users, at least not yet. Adolescents may be supplementing their standard cannabis smoking with new forms of cannabis use, or they may be substituting new forms (e.g. vaping and edibles) for smoking."
"We hope our study raises awareness of people who are concerned about the health of teens that these products exist, that they are commonly used, and it would be worth opening up a line of dialogue between teens and teachers and parents about these products," Leventhal said.