Smoking among Minnesota teenagers has dropped to an all-time low, and other risky behaviors such as sexual activity and marijuana use are continuing a steady long-term decline.

At the same time, the number of teens reporting emotional or mental health problems has risen sharply, and teen use of tobacco and alcohol show persistent gaps along lines of race and income.

But overall, the latest Minnesota Student Survey, released Tuesday by the Department of Health, paints an encouraging picture of the state’s adolescents, public health officials said.

“Youth tobacco use is a harbinger of long-term good health,” said Laura Oliven, tobacco control manager for the Health Department. “If we can prevent youth from smoking by age 18, we have a much better shot at preventing them from becoming long-term smokers.”

Minnesota’s youth-smoking numbers match national statistics showing steep declines from peak levels in the late 1990s.

The survey, which is conducted every three years, also found that students generally gave high marks to their own health and said they felt safe at home, at school and in their neighborhoods.

They also felt highly engaged in school, with nearly two-thirds of respondents involved in out-of-school activities at least three days a week. It also found a sharp drop in use of indoor tanning devices by teen girls, following a ban for teenagers adopted by the Legislature.

While the trends are generally positive, disparities still exist for students of color, students living in poverty, American Indian and gay, lesbian or bisexual students. And in a sign that “vaping” is catching on, twice as many 11th-graders admitting to using e-cigarettes as those who lit up a traditional cigarette.

There also was a slight uptick overall in the number of students considered obese.

“That is not the direction that we want to see things going,” said Pete Rode, a Health Department research scientist. “It was not a sharp increase, but noticeable after a couple of years of being totally flat.”

The voluntary survey, completed by 169,000 students in the 85 percent of public school districts that participated, will help public health and school officials throughout the state craft targeted health improvement campaigns.

The new data are valuable because they show teens that smoking, drinking and sex are not widespread among their peers, health officials said.

“Teens want to fit in and do what other teens are doing,” said Holly Magdanz, who heads health promotion efforts for the Hopkins Public Schools. “Teens tend to underestimate healthy behaviors and overestimate unhealthy behaviors.”

Magdanz, who trained in public health and social work, has been waiting for the survey data to continue the district’s health promotion efforts. Many programs work through a community alliance known as the Hopkins One Voice Coalition, which got its start in the 1990s, when the student survey showed higher levels of student substance abuse.

The coalition’s program on alcohol, for example, reinforces the fact that abstaining is common. Many students are surprised to learn that only one-fifth of other students had used alcohol, Magdanz said.

The coalition has messages for parents as well. Although the data does not identify students by name, school districts are able to analyze results for their student populations to tailor preventive campaigns.

One analysis found that students were six times less likely to report marijuana use if they thought their parents would disapprove.

“We really stress with parents that talking with your teen or tween about these topics is important,” Magdanz said. “Just by sharing your disapproval and your expectations, it can influence their decision.”

Hopkins Public Schools also has a program, suggested by high school students, that teaches ninth-graders, who in the district are considered to be in junior high, what to expect in high school.

“Times of transition are times of higher risk. Substance use can happen at the time of transition,” Magdanz said.

While most of the questions that ninth-graders ask older students are common concerns, such as the quality of the cafeteria food, the schools aim to ease the anxiety that might come with change to prevent kids from trying risky behaviors.

“Being safe is certainly an issue,” Magdanz said. “I think kids are really looking for a healthy future.”