WASHINGTON - An anti-smoking group is reigniting its pressure on the FDA to study the safety, ingredients and potential health impacts on consumers of electronic cigarettes.

The Hill reports that the request from the American Cancer Society Cancer Action Network comes after the release of a U.S. Centers for Disease Control study that found one in five U.S. adult cigarette smokers have tried an electronic cigarette.

In 2011, about 21% of adults who smoke traditional cigarettes had used electronic cigarettes, also known as e-cigarettes, up from about 10 percent in 2010, according to the CDC. Overall, about 6% of all adults have tried e-cigarettes, with estimates nearly doubling from 2010. The CDC study is the first to report changes in awareness and use of e-cigarettes between 2010 and 2011.

During 2010-2011, adults who have used e-cigarettes increased among both sexes, non-Hispanic Whites, those aged 45-54 years, those living in the South, and current and former smokers and current and former smokers. In both 2010 and 2011, e-cigarette use was significantly higher among current smokers compared to both former and never smokers. Awareness of e-cigarettes rose from about four in 10 adults in 2010 to six in 10 adults in 2011.

"E-cigarette use is growing rapidly," said Tom Frieden, director of the Office on Smoking and Health at CDC. "There is still a lot we don??t know about these products, including whether they will decrease or increase use of traditional cigarettes."

The CDC noted that although e-cigarettes appear to have far fewer of the toxins found in smoke compared to traditional cigarettes, the impact of e-cigarettes on long-term health must be studied.

"If large numbers of adult smokers become users of both traditional cigarettes and e-cigarettes ?" rather than using e-cigarettes to quit cigarettes completely ?" the net public health effect could be quite negative," added Frieden.

Chris Hansen, president of American Cancer Society Cancer Action Network, said in a statement that e-cigarettes target children. "E-cigarettes are often manufactured to resemble traditional cigarettes, and are available in fruit and candy flavors that are appealing to youth. The familiar appearance and enticing flavors could actually encourage kids to try traditional cigarettes, rather than avoid them."

Hansen added that his group is calling on the FDA to "determine if e-cigarettes are safe for use and whether they can help youth and adults avoid actual cigarettes or quit the habit. We also urge the FDA to test these products to determine their potential as cessation aids so consumers have the best information available when deciding how to quit."

Meanwhile, the electronic cigarette industry is fighting back against the calls for increased regulations, notes The Hill. In January, The Consumer Advocates for Smoke-free Alternatives Association (CASAA) with the White House to prevent the FDA from regulating or banning the sale and use of electronic cigarettes, accessories and associated liquids.

"The FDA should not propose or approve any regulation that would deny cigarette smokers legal or affordable access to less hazardous smoke-free alternatives," wrote CASAA advisor Bill Godshall in the petition. A reply to the petition from the White House is pending.