Public health officials are concerned that e-cigarettes may be recruiting a new generation of young cigarette smokers as the e-cigarette use among teenagers in the United States and Hawaii continue to rise, according to a recent study.

Researchers from the University of Hawaii Cancer Center found that nearly 30 percent of nearly 2,000 teens surveyed in Hawaii had tried e-cigarettes, and of those, 17 percent were using e-cigarettes only, the Examiner reported.

E-cigarettes are battery-powered vaporizers that deliver nicotine in a fine aerosol mist.

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

For the study, 14 and 15 year olds took a survey that assessed e-cigarette and cigarette use, alcohol and marijuana use, and psychosocial risk factors for substance use.

Based on the results, researchers found that 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.

They also found that 12 percent of the teens surveyed used both e-cigarettes and cigarettes; 3 percent used cigarettes only; 68 percent did not use either e-cigarettes or cigarettes; 96 percent of the participants were aware of e-cigarettes; and 67 percent considered e-cigarettes to be healthier than cigarettes.

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.

Wills also said e-cigarettes are widely available in the absence of restrictions on their sale, and that may help explain why the rate of use is so high in Hawaii.

"The marketing is very aggressive here," he said, adding that manufacturers place ads at venues such as movie theaters that are accessible to teenagers.

They also make flavored liquids in varieties such as mango and pineapple. Other reasons could include the high tax rate on cigarettes in Hawaii, which makes alternatives such as e-cigarettes more attractive from a cost perspective.

The findings, which are published in the journal Pediatrics, come as e-cigarettes grow in popularity and the Food and Drug Administration is considering how to regulate their sale.