People who use e-cigarettes are often inhaling high levels of nicotine, but many teenagers who vape don't realize it, according to a new study in the journal Pediatrics.
NBC News reported that 40 percent of teens who thought their e-cigarettes were free of nicotine tested positive for it.
"This is one of the first studies showing the amount of nicotine kids are getting from e-cigarettes," said the study's lead author, Dr. Rachel Boykan, a clinical associate professor of pediatrics at Stony Brook University. "They're getting a lot — as much or more than they would with traditional cigarettes."
Some experts think e-cigarettes that contain nicotine may produce a generation of young addicts who may later turn to cigarettes.