The use of electronic cigarettes by middle and high school students in the United States has dropped for the first time since the federal government started tracking the use of these products by young people.
The number of teenagers using e-cigarettes fell from 3 million in 2015 to 2.2 million in 2016, according to a report published Thursday in Morbidity and Mortality Weekly Report.
"It's actually quite remarkable from a public health standpoint," says Brian King, deputy director for research translation in the Centers for Disease Control and Prevention's Office on Smoking and Health, which produced the report.
Before the drop, the CDC had documented an exponential increase in the use of e-cigarettes by young people between 2011 and 2015, King says. That prompted widespread alarm among public health authorities. The devices were first imported into the U.S. from China in 2006.
E-cigarettes are devices that heat up a fluid containing nicotine to produce a vapor that users inhale; thus their use is sometimes called "vaping."
While e-cigarettes are believed to be less dangerous than smoking traditional tobacco cigarettes, their popularity has sparked an intense debate over benefits and harms.
Some public health researchers believe the devices could help prevent some people from starting to smoke tobacco cigarettes, or help smokers reduce the number of cigarettes they smoke or even kick the habit completely.
But the use of the devices among young people has triggered concern for a variety of reasons. Nicotine is believed to be dangerous for the developing brain, for example. There are also concerns that the vapor produced by the devices may contain hazardous ingredients. Some also worry the devices could hook a new generation on nicotine, which is addictive, thus leading more to start smoking regular cigarettes.
In December, the U.S. surgeon general said that "e-cigarettes have the potential to cause lasting harm to the health of young users."
King attributed the drop in e-cigarette use to a variety of factors, including high-profile public education campaigns about the potential dangers of e-cigarettes. New restrictions on sales to minors also probably played a role, he says.
While King says the drop is good news, he stressed that too many young people are still using the devices, as well as other tobacco products.
"We've made a lot of great progress, but we still have millions of youth that are using a product that is detrimental to their health," King says.
According to the report, e-cigarette use among high school students fell from 16 percent in 2015 to 11.3 percent in 2016. E-cigarette use among middle school students fell from 5.3 percent to 4.3 percent over that same period.
The drop was hailed by anti-smoking advocates.
"While the number of high school students who use e-cigarettes is still too high, this rapid decline is a positive indicator that much youth e-cigarette use has been experimental and that the current offering of products may be less appealing to youth than feared," Robin Koval, the CEO and president of the Truth Initiative, said in a statement.