A new survey finds 73 percent of U.S. teens think e-cigarettes are less harmful than regular cigarettes. The researchers say teens who use e-cigarettes are more likely, than those who do not, to go on to use traditional cigarettes, HealthDay reports.

The survey, published in the journal Pediatrics, found 47 percent of teens believe e-cigarettes are less addictive than cigarettes.

“Concern exists that e-cigarettes are re-normalizing smoking,” said Dr. Stephen Amrock, from the department of medicine at Oregon Health and Science University in Portland. “Children and parents need to understand that these products contain nicotine and are potentially harmful, both now and because they have been linked to later cigarette use.”