Use of e-cigarettes has more than tripled among middle school and high school students since 2011, with 16% of high school students reporting use of a vaping product within the past 30 days in 2015 and 40% reporting having used e-cigarettes at least once.

In a press briefing Thursday morning, Surgeon General Vivek Murthy, MD, said that while more research into the health impact of e-cigarettes is needed, it is already known that nicotine exposure can harm the developing adolescent brain.

"The message from the report is clear. Nicotine-containing products, including e-cigarettes, are not safe for youth," he said.

Murthy noted that use of e-cigarettes among adolescents and young adults "went from being rare in 2010 to being the most common tobacco product used [by] kids, teens, and young adults in the U.S, surpassing traditional cigarettes, hookah, and chewing tobacco."

"This represents a staggering development in a relatively short period of time," he said. "It also threatens 50 years of hard-fought progress in curbing tobacco use and it places a whole new generation at risk for addiction to nicotine."

The report calls on lawmakers at all levels of government to take action to address the rising use of e-cigarettes among kids, adolescents, and young adults, including:

• Incorporating e-cigarettes into smoke-free policies

• Passing laws to prevent the purchase of vaping products by children and teens

• Significantly increasing taxes on e-cigarettes

• Regulating e-cigarettes marketing that is aimed at youth and young adults

• "Many e-cigarette companies are using advertising and strategies employed by the traditional cigarette industry, including the use of flavorings, celebrity endorsements, themes such as rebellion and sex, and sponsorship of sports and music events," Murthy said. "These strategies are working to reach kids."

He noted that in a 2014 survey, seven out of 10 middle school and high school students reported having seen e-cigarette advertisements.

"To be certain, there is more to learn about e-cigarettes, including the full health impact that e-cigarettes have and the factors that lead to youth use," he said. "Additionally, the important question about whether e-cigarettes can help adults quit smoking has yet to be answered with high quality scientific data."

Murthy said it is important to remain open-minded about the potential role e-cigarettes might play in helping adult smokers kick the cigarette habit.

"But we now know enough about the potential health risks of e-cigarettes to young people to take action," he said.

American Academy of Pediatrics President Benard Dreyer, MD, highlighted concerns about the potential dangers of secondhand e-cigarette smoke and e-cigarette liquid poisoning at Thursday's press conference.

"The Surgeon General's report clearly states that aerosol from e-cigarettes is not harmless," he said. "It includes nicotine and other potentially harmful chemicals, including heavy metals and carcinogens. Since there is no safe level of exposure, it is especially important to protect children from secondhand e-cigarette aerosol."

He added that liquid nicotine used in e-cigarettes comes in more than 7,000 different flavors, including Gummy Bear and Cotton Candy, that are marketed to be appealing to children.

Regulation of e-cigarettes by the FDA went into effect in August, and their sale is now prohibited to anyone under the age of 18. Distribution of free samples of e-cigarettes and vending machine sales are also prohibited, but the new regulations did not remove flavored e-cigarettes from the market, as anti-smoking groups had hoped.

The newly released report noted that flavored e-cigarette use among users younger than 25 exceeds that of older users, and that a majority of adolescent e-cigarette users report using flavored products the first time they vaped

"The most commonly cited reasons for using e-cigarettes among both youth and young adults are curiosity, flavoring/taste, and low perceived harm compared to other tobacco products," the report stated.

It also noted that e-cigarette use is "strongly associated with the use of other tobacco products among adults and young adults."