One out of 5 high school seniors say they have vaped, according to a University of Michigan study.

Dr. Paul Mustacchia, of Nassau University Medical Center, says it's a common misconception that vaping is safer than smoking traditional cigarettes.

"Any substance that you inhale could potentially hurt you," he says. "The lungs are a vehicle to get into your body, so vaping could hurt you."

He also says marketing for vaping and related products could be targeting children. In response, doctors have written a letter to Suffolk County legislators asking them to limit the amount of flavors added to vaporizors, which they believe is attractive to teens.

Doctors say education is the key to reverse the trend.

Teens told researchers that after vaping, alcohol remains popular, followed by marijuana. One in 4 teens said they have used marijuana, which has stayed at the same level. Vaping marijuana has gone up.