E-cigarette use among teenagers is growing in the U.S., and Hawaii teens take up e-cigarette use at higher rates than their mainland counterparts, a new study by University of Hawaii Cancer Center researchers has found. The findings come as e-cigarettes grow in popularity and the Food and Drug Administration is considering how to regulate their sale. Some public health officials are concerned that e-cigarettes may be recruiting a new generation of young cigarette smokers who otherwise might not take up smoking at all, and the study's results bolster this position.

Data from the study published in the journal Pediatrics showed that nearly 30 percent of the more than 1,900 teens surveyed in Hawaii had tried e-cigarettes, and of those, 17% were using e-cigarettes only. The overall rate is about three times larger than previously reported in U.S. studies in 2011 and 2012, which showed rates of 4.7 percent and 10 percent respectively. Additionally, very few adolescents in the national studies are e-cigarette only users.

The Hawaii teens were 14 and 15 years old and surveyed in public and private schools in 2013. The survey questions assessed e-cigarette and cigarette use, alcohol and marijuana use, and psychosocial risk factors for substance use. Teenagers who used only e-cigarettes were intermediate in levels of risk and protective factors between nonusers and those who used both cigarettes and e-cigarettes. This raises a question about whether e-cigarettes are recruiting low-risk youth (who would otherwise not try smoking) to tobacco product use.

Researchers also found: 12% used both e-cigarettes and cigarettes; 3% used cigarettes only; 68% did not use either e-cigarettes or cigarettes; 96% of the participants were aware of e-cigarettes; 67% considered e-cigarettes to be healthier than cigarettes

Dr. Thomas Wills, PhD, the interim director of the UH Cancer Center's Prevention and Control Program, said researchers aren't sure why the rate of e-cigarette use is so high among teens in Hawaii. The health benefits and risks of e-cigarettes remain under debate, but Wills cautioned parents and teens.

"You have to think carefully about the risks and benefits of using either tobacco or nicotine, which is known to be an addictive substance," he said. "A lot of teens think it is easy to quit smoking but it isn't true. It's hard for anybody to quit."