An unidentified 15-year-old high school student displays a vaping device near the school's campus in Cambridge, Massachusetts, April 11, 2018. Credit: Steven Senne | AP

After years of decline, the percentage of American teenager who report smoking cigarettes rose last year. The percentage of teens who routinely use e-cigarettes continues to rise as well.

Although the numbers are small, a rise in teen smoking rates is cause for concern. Nearly 90 percent of current adult smokers began before they were 18. So, reducing teen smoking rates can have long-term positive consequences. Tobacco-related illnesses are the leading cause of preventable death in the United States, costing the U.S. about $300 billion a year in health care costs and lost productivity due to illness and premature deaths.

According to data released by the Centers for Disease Control and Prevention earlier this month, last year 8.1 percent of high school students reported smoking cigarettes in the prior 30 days. That’s an an increase from 7.6 percent in 2017. Previously, the rate had been declining. The data are from the CDC’s National Youth Tobacco Survey.

[Opinion: We cannot let e-cigarettes become an on-ramp for teenage addiction]

Overall use of tobacco products rose as well. In 2018, 27 percent of high school students reporting using tobacco products, including e-cigarettes. That’s a significant increase from nearly 20 percent the previous year.

E-cigarettes are the most commonly used tobacco products by teens, and their use is increasing. Last year, nearly 21 percent of high school students reported using e-cigarettes, a big jump from nearly 12 percent in 2017.

Here in Maine, 15 percent of high school students in a 2017 survey reported using e-cigarettes in the previous month.

Vaping is popular among teens because of cartridges that look like USB drives, which can be hidden from parents and school officials. They also come in flavors that appeal to teens, but have a high nicotine content.

The trend is troubling, but there is a conundrum with e-cigarettes. While early data show that vaping is a gateway to youth smoking, vaping has also been shown to help adults stop smoking cigarettes.

A study, published last month in the New England Journal of Medicine, found that e-cigarettes were more effective at smoking cessation than nicotine replacement products. This follows similar findings in England, which prompted the Royal College of Physicians to endorse e-cigarettes as a valuable tool in helping people to quit smoking. In England, e-cigarettes are now the most commonly used anti-smoking aid.

The challenge then for the Food and Drug Administration, which regulates tobacco products nationwide, and other policymakers is to find a balance that keeps e-cigarettes available to adults while minimizing their availability to children.

Maine has taken steps to reduce teen smoking and vaping. Last year, Maine raised its tobacco purchase age to 21. This includes e-cigarettes. However, people who turned 18 by July 1, 2018 are grandfathered and able to legally purchase tobacco products in the state. Maine is among six states and hundreds of municipalities that have raised the tobacco purchase age to 21.

[Editorial: Rapid increase in vaping threatens to reverse decline in teen smoking]

One rationale for the change is that raising the age to 21 would have a significant effect on high school-age smokers and potential smokers, because their 18- to 20-year-old peers no longer would be able to legally purchase tobacco for them. Breaking this link for e-cigarette purchases makes sense as well.

Sen. Rebecca Millett, D-Cape Elizabeth, has introduced a bill that would ban the possession and use of electronic smoking devices on school grounds by both students and staff. Smoking is already banned on school grounds. School officials and students testified in favor of the ban at a public hearing last week.

Another bill, LD 508, sponsored by Rep. Nicole Grohoski, D-Ellsworth, calls for a study potential restrictions on tobacco marketing with an emphasis on steps the state can take to restrict such marketing, especially of e-cigarettes, to both adults and children.

These bills will prompt needed discussion, but lawmakers must be certain they don’t succumb to overreach that harms the aims of protecting children and reducing smoking rates among adults.