A person vapes on the street in July in New York. The percentage of middle and high school students reporting that they vaped tobacco products declined to about a third of the peak levels in 2019, a new survey shows. (Justin J Wee/The New York Times)

The number of teenagers who reported using e-cigarettes in 2024 has tumbled from a worrisome peak reached five years ago, raising hopes among public health officials for a sustained reversal in vaping trends among adolescents.

In an annual survey conducted from January through May in schools across the nation, fewer than 8% of high school students reported using e-cigarettes in the past month, the lowest level in a decade.

That's far lower than the apex, in 2019, when more than 27% of high school students who took the survey reported that they vaped -- and an estimated 500,000 fewer adolescents than last year.

The data is from the National Youth Tobacco Survey, a questionnaire filled out by thousands of middle and high school students that is administered each year by the Food and Drug Administration and the Centers for Disease Control and Prevention. Overall, it found that just under 6% of middle and high school students reported vaping in the last month, down from nearly 8% among those surveyed last year.

Public health experts said several factors may have contributed to the decline in teenage vaping, including flavored tobacco bans, a blitz of enforcement against sellers and public messaging campaigns about the dangers of vaping.

Some compared the news to the decline in smoking traditional cigarettes, which at about 1.6% of teenagers, has reached a notable low.

Many public health groups have raised alarms about the potential effects of e-cigarettes on young people, including exposure to toxins and carcinogens -- some of which are still unknown. Nicotine levels in these products can be very high, raising the risk of addiction and injury to the developing brains of adolescents.

"Definitely, risk perceptions of vaping have increased," said Kathy Crosby, president of the Truth Initiative, a nonprofit group that campaigns against youth vaping. "And as you see the increase in risk perceptions, you also see decreasing behaviors."

Some health officials cautioned that problems are still cropping up. The latest youth tobacco survey tracked an emergence of youth use of nicotine pouches such as Zyn, though at low levels, with about 2% of adolescents reporting use.