A new federal survey has found that e-cigarette use among teenagers has surpassed the use of traditional cigarettes, even as smoking of traditional cigarettes has continued to decline. Health advocates say the upward trend for e-cigarette use is dangerous because it is making smoking seem normal again. They also worry it could lead to an increase in smoking of traditional cigarettes, though the new data do not show that.

The survey, released Tuesday by the National Institute on Drug Abuse, measured drug and alcohol use this year among middle and high school students across the country. More than 41,000 students from 377 public and private schools participated. It is one of several such national surveys, and the most up-to-date.

E-CigarettesIt was the first time this survey measured e-cigarette use, so there were no comparative data on the change over time. Other surveys have shown e-cigarette use among middle and high school students to be much lower, but increasing fast.

“The numbers are stunning,” said Matthew L. Myers, president of theCampaign for Tobacco Free Kids, an advocacy group.

The survey found that 17 percent of 12th graders reported using an e-cigarette in the last month, compared with 13.6 percent who reported having an traditional cigarette. Among 10th graders, the reported use of e-cigarettes was 16 percent, compared with 7 percent for cigarettes. And among 8th graders, reported e-cigarette use was 8.7 percent, compared with just 4 percent who said they had smoked a cigarette in the last month.

A 2013 youth tobacco survey by the federal Centers for Disease Control and Prevention released in November found that the share of American high school students who use e-cigarettes rose to 4.5 percent in 2013 from 2.8 percent in 2012. The share of middle school students who use e-cigarettes remained flat at 1.1 percent over the same period.

E-cigarettes have split the public health world, with some experts arguing that they are the best hope in generations for the 18 percent of Americans who still smoke to quit. Others say that people are using them not to quit but to keep smoking, and that they could become a gateway for young people to take up real cigarettes.

But that does not seem to be happening, at least so far. Daily cigarette use among teenagers continued to decline in 2014, the survey found, dropping across all grades by nearly half over the past five years. Among high school seniors, for example, 6.7 percent reported smoking cigarettes daily in 2014, compared with 11 percent five years ago.

Most experts agree that e-cigarettes are far less harmful than traditional cigarettes. But they contain nicotine, an addictive substance that some experts contend is potentially harmful for brain development. Some experts also warn that nicotine use could establish patterns that leave young people more vulnerable to addiction to other substances.