WASHINGTON - The number of middle and high school students using electronic cigarettes tripled between 2013 and 2014, according to government figures released Thursday, a startling increase that public-health officials fear could reverse decades of efforts combating the scourge of smoking.
The popularity of e-cigarettes among teenagers now eclipses traditional cigarettes, the use of which has fallen to the lowest level in years.
Tom Frieden, director of the Centers for Disease Control and Prevention, called the spike in e-cigarette use "shocking."
"It's a really bad thing, and it is subjecting another generation of our children to an addictive substance," he said in an interview, adding that any type of nicotine exposure can harm the teenage brain and that some e-cigarette smokers undoubtedly will go on to use traditional cigarettes.
Not everyone sees such cause for alarm in the new numbers.
"The CDC should really be jumping for joy at the fact that smoking rates are declining. This is a huge success," said Michael Siegel, a professor and tobacco control specialist at Boston University's School of Public Health. "Instead, they are using this as another opportunity to demonize e-cigarettes."
Siegel said he agrees that minors shouldn't have access to any tobacco product. But he said the CDC numbers suggest that rather than serving as a gateway to cigarette smoking, e-cigarettes might be diverting teens from traditional cigarettes, which still account for nearly a half-million tobacco-related deaths in the United States each year.
Thursday's findings came as little surprise to many educators around the country, who have increasingly wrestled with how to handle the swift rise in e-cigarette use among students.
Patricia Sheffer, superintendent of Union County Public Schools in Kentucky, grew so frustrated this year over the dozens of incidents of students being caught with e-cigarettes that last month she sent a recorded message to district parents and posted a plea on Facebook asking for help cracking down on the problem. The K-9 dogs that perform a sweep of the schools about once a month also are being trained to sniff out e-cigarettes, she said.
"It's just growing at such a rapid pace," said Sheffer, who worries about the various substances students might be smoking in the devices. "I thought, 'We have to take a stand.' "
Districts around the country, such as Haywood County Schools in North Carolina, have begun classifying e-cigarettes as drug paraphernalia, rather than as normal cigarettes, in the hope that the harsher penalties will discourage students from bringing them to campus.
Antismoking advocates insist the rise in the popularity of e-cigarettes stems in part from aggressive marketing campaigns that Frieden called "straight out of the playbook" of ads that targeted young people in earlier generations.
E-cigarettes remain unregulated by the federal government, although numerous cities and states have passed laws restricting sales to minors and banning the devices in public places. But e-cigarettes do not face the same federal restrictions on television and radio advertising that apply to traditional cigarettes.
At the heart of the public-health debate over e-cigarettes lies a series of unanswered questions: Are e-cigarettes unequivocally less harmful than tar-laden, chemical-filled tobacco cigarettes, as many people assume? Will they prove to be a healthier alternative that helps people avoid cigarette smoking and reduce tobacco-related deaths, or simply devices that could undermine decades of public health efforts?
Siegel, the Boston University professor, said it "shouldn't take a rocket scientist" to figure out that "vaping" is safer than smoking, given that the liquids used in e-cigarettes involve no combustion and very few chemicals. And Cabrera said regulators shouldn't "lose perspective about the potential" for e-cigarettes to eliminate harm caused by smoking cigarettes.
But plenty of uncertainty remains. A study this week in the journal Tobacco Control, for instance, found that the chemicals used to flavor e-cigarettes could prove unsafe when inhaled over time. Public health officials say far more research is needed given how little data exist on the long-term effects of e-cigarettes.
This much seems certain from Thursday's results, based on an annual survey of 22,000 students around the country: Teens are experimenting as much as ever. Roughly a quarter of high school students and nearly 8 percent of middle school students still report having used a tobacco product at least once during the previous 30 days.
But between 2013 and 2014, the findings say, e-cigarette use among high school students had increased from 4.5 percent to 13.4 percent.
During that same period, the use of hookahs - water pipes used to smoke specially made tobacco - roughly doubled for middle and high school students, equaling and eclipsing the use of regular cigarettes, respectively. Meanwhile, the use of conventional cigarettes sank to the lowest levels in years. According to the CDC, 9.2 percent of high school students reported smoking a cigarette over the past month, compared with 12.7 percent a year earlier.