Tobacco use by young Minnesotans has increased for the first time in 17 years, driven by a 50-percent increase in teen use of e-cigarettes in the past three years, the Department of Health reported Thursday.

While the number of teenagers smoking conventional cigarettes continued to decline to less than 10 percent of high school students, state health officials said that progress could be undermined by the rise of e-cigarettes.

The numbers, released as part of the state's 2017 youth tobacco survey, come on the heels of a federal report indicating that teens are twice as likely to try cigarettes if they first use e-cigarettes.

The state's new health commissioner, Jan Malcolm, blamed tobacco companies for marketing e-cigarettes in ways that appeal to children, including selling liquid cartridges in fruit and candy flavors.

"Just as we reduced cigarette usage to under 10 percent of high school students — giving us the hope that a smoke-free generation was in reach — the industry responded with new products designed to get youth addicted to nicotine," Malcolm said.

TMA, a leading industry trade group, did not respond to a request for comment Thursday.

While numerous signs have pointed to e-cigarettes' popularity among teens, the youth tobacco survey, which canvasses public school students in grades six through 12, is considered a definitive source. It has been conducted every three years since 2000.

Among high school students, 19.2 percent said they used e-cigarettes in the 30 days before completing the 2017 survey — up from 12.9 percent in 2014. The share of high school students who used any form of tobacco increased over the same period from 24.6 percent to 26.4 percent.

News of rising e-cigarette use came as little surprise Thursday morning to four students in a school leadership organization at Johnson Senior High School in St. Paul. All four had tried e-cigarettes.

One recalled a student using an e-cigarette two years ago in the back row of a class, because he didn't think it was smoking or violated school policy. All four said they believe e-cigarettes are hazardous but said friends don't think that way.

"They think it's just, like, air and steam and stuff," said senior Kaung Win, who tried an e-cigarette on a dare.

Senior Tule Xiong said he tried discouraging friends from vaping, but over time he started to use e-cigarettes himself for occasional stress relief. "I don't know what happened," he muttered.

Gateway drug?

E-cigarettes are battery-operated heating elements that convert cartridges of liquids containing varying amounts of nicotine into inhaled vapor — hence the nickname vaping.

Many adult users have reported that vaping helped them give up cigarettes. A recent report from the National Academies of Sciences, Engineering and Medicine acknowledged that e-cigarettes can help adults quit smoking, noting that e-cigarettes contain fewer cancer-causing chemicals than traditional cigarettes.

However, the study said there is no evidence that e-cigarettes are safer for teens and said they might serve as gateway drugs that lead teens to cigarettes or other substances.

Results from the latest state survey, which included 4,112 students, showed that one in three high school students who recently used e-cigarettes had also tried using the devices to smoke marijuana.

E-cigarettes are a "platform for illicit drugs," said Dr. Peter Dehnel of the Twin Cities Medical Society, but he added that nicotine itself is harmful to children.

"Even in small doses, nicotine exposure in adolescents causes long-term and lasting changes in brain development," he said, "which can have negative implications for adolescent learning, memory, attention, and behavior."

State health officials urged communities to restrict access by raising the legal age for purchasing all tobacco products, currently 18 across most of Minnesota, and limiting locations where flavored and menthol tobacco products can be sold.

ClearWay Minnesota, an advocacy group that aims to reduce tobacco use and exposure to secondhand smoke, lists 23 counties and 31 cities as expanding their clean indoor air policies to include e-cigarettes. Edina, St. Louis Park, Bloomington and Plymouth increased the minimum age for tobacco purchases from 18 to 21 last year.

Minneapolis and St. Paul both banned convenience stores from selling the candy- or fruit-flavored e-cigarette cartridges that appeal to minors.

At the convenience store a block from Johnson High on Thursday, only a small selection of standard flavors was available behind the counter.

Secret vaping lounge

Malcolm announced the survey results in her first public health news conference since being reappointed commissioner. She held the same post from 1999 to 2003, and she presided over the first state youth tobacco survey.

"It's kind of fitting for my first press conference ... that we're still talking about the critical issue that tobacco is for the health of our state," she said.

Malcolm said new policy proposals have been discouraged in the upcoming limited session of the state Legislature, but said she would forward the survey data to lawmakers anyway.

Joining state officials at the news conference was Sagit Nachmias, a junior at Hopkins High School. She advocated an increase from 18 to 21 in the minimum age for buying tobacco products in her hometown of Plymouth.

Nachmias said one restroom at her high school has basically become a "secret vaping lounge" and that it has almost become a competition among classmates to try different flavors.

Many start with nicotine-free versions but switch over time, she added. "They still don't consider it to be smoking."