(HealthDay)—Many American adults who use electronic cigarettes also smoke tobacco cigarettes, a U.S. Centers for Disease Control and Prevention survey reveals.
The survey found that in 2015, 59 percent of all adult e-cigarette users were also current cigarette smokers. The survey also showed that 30 percent of e-cigarette users were former smokers and 11 percent using the devices had never smoked.
Among young adults ages 18 to 24, 40 percent of e-cigarette users were never smokers, 43 percent were current smokers and 17 percent were former smokers.
"If there is a public health benefit to the emergence of e-cigarettes, it will come only if they are effective at helping smokers stop using cigarettes completely, responsibly marketed to adult smokers and properly regulated to achieve these goals," said Matthew Myers, president of the Campaign for Tobacco-Free Kids.
Altogether, 3.5 percent of all U.S. adults were e-cigarette users in 2015, down slightly from 3.7 percent in 2014, the CDC survey found.
Myers said these findings raise concerns that many adults using e-cigarettes are using the devices in addition to tobacco cigarettes, rather than in place of them.
Myers' organization also said the finding that 40 percent of young adults who use e-cigarettes have never been smokers raises concerns that e-cigarettes may be introducing young nonsmokers to tobacco use and nicotine addiction.
There has been a sharp increase in use of e-cigarettes by youth. In 2015, 24 percent of high school students were current users of e-cigarettes, compared to 11 percent who smoked cigarettes, a previous CDC survey found.
E-cigarettes "will not benefit public health if smokers use them in addition to cigarettes instead of quitting or if they re-glamorize tobacco use among young people and attract nonsmokers," Myers said in a Campaign for Tobacco-Free Kids statement.
Current evidence on whether e-cigarettes help smokers quit is limited and inconclusive, he said.
Explore further: Study finds perception of e-cigarette harm growing among US adults
The U.S. National Institute on Drug Abuse has more about e-cigarettes.