E-cigarette warning as vaping outstrips puffing

Turns out, e-cigarettes are really a gateway drug, luring non-smokers into trying vaping.

A new USC study debunked the popular belief that electronic cigarettes are merely a substitute for cigarettes among teens. Instead, it suggested that some teens who never would have smoked cigarettes are now vaping.

E-cigarettes, which entered the U.S. market in 2007, vaporize liquids that may or may not contain nicotine. In 2011, about 1.5 percent of high schoolers had vaped in the past 30 days, according to the National Youth Tobacco Survey. Four years later, that number skyrocketed to 16 percent.

The study of 5,490 high school juniors and seniors showed tobacco use among teens in Southern California is on the rise.

In 2014, about 14 percent of 12th-graders said they had either smoked or vaped in the previous 30 days. A decade earlier, before e-cigarettes were sold in the United States, 9 percent of surveyed teens in this age group reported that they had smoked, said lead author Jessica Barrington-Trimis.

"If teenagers who vape are using e-cigarettes instead of cigarettes, we would have expected to see the decline in smoking rates continue through 2014," Barrington-Trimis noted.

She added, "But what we've seen is a downward trend in cigarette use from 1995 to 2004 but no further decrease in cigarette smoking rates in 2014. The combined e-cigarette and cigarette use in 2014 far exceeded what we would have expected if teens were simply substituting cigarettes with e-cigarettes. The data suggest that at least some of the teens who are vaping would not have smoked cigarettes."

Cigarette use is the largest preventable cause of death and disease in the United States. Cigarette smoking kills more than 480,000 Americans annually, according to the Centers for Disease Control.

"An important question in the rapidly evolving landscape of youth tobacco product use is whether e-cigarettes are replacing cigarettes," said senior author Rob McConnell.

He continued, "However, use of e-cigarettes by youth who would not otherwise have smoked results in exposure to the hazards of inhaled vaporized liquids and flavorings in e-cigarettes and may result in exposure to nicotine that can damage the adolescent brain."

"E-cigarettes may be recruiting a new group of kids to tobacco use," Barrington-Trimis said. "E-cigarettes may be safer than regular cigarettes for adults who are transitioning from smoking to vaping, but for youth who have never used any other tobacco products, nicotine experimentation could become nicotine addiction."

The study is published in the journal Pediatrics.