GUILFORD COUNTY -- A new study published in the Journal of Pediatrics reveals teens are using e-cigarettes to smoke marijuana.    

Yale University researchers conducted the survey that questioned more than 3800 students in 2014 at Connecticut high schools. The results showed 27.9 percent of high schoolers said they use e-cigarettes and 18.7 percent are “dual users,” who use it to also vaporize marijuana.

However, that trend doesn’t seem as frequent in the Triad. The Guilford County Sheriff’s Office said School Resource Officers haven’t seen any cases yet.

“Whether that's because they haven't necessarily known what they were looking for, it's not something we've had a lot of knowledge of prior to very recently," Lt. Brian Hall said. "It's not something they've been trained to look for. It's pretty much a new trend."

E-cigarettes are powered by batteries and turn on a heating element when a person inhales that vaporizes the liquid inside small tubes. In the study some teens admitted to using hash oil, dried cannabis leaves or wax infused with Tetrahydrocannabinol (THC)--an active ingredient in marijuana. 

Greensboro Police Department reports it's had one case. A Winston-Salem Police Department detective says they've had less than five cases in two years and they all involved adults.