For decades, any would-be soldier, sailor, airman or Marine has had to check a box on a form at their initial medical processing, declaring whether or not they smoke cigarettes. But despite the rise in its popularity, that form still doesn’t ask a thing about vaping.

The Defense Department needs to update its records to better track the use of e-cigarettes in the ranks, according to a military manpower expert with CNA, a nonprofit research and analysis organization in Arlington, Virginia, the same way it keeps records of which troops are smokers.

“There is no time like the present for DoD to be concerned about the growing trend of e-cigarette use among America’s youth,” Elizabeth Clelan wrote.

Clelan outlined her concerns in a blog posted Friday, a follow-up to her past research on the topic.

In 2016, CNA published “Potential Consequences of E-Cigarette Use: Is Youth Health Going Up in Smoke?", a study that found youth e-cigarette use was linked to a higher use of traditional cigarettes, among the roughly 10 percent of youth who were vaping at the time.

That number has doubled in the two years since, Clelan wrote. And, she added, the DD 2807-2 form that once helped the services track tobacco use got rid of the cigarette question altogether in 2011.

It’s concerning, she wrote, that while teen use of nicotine products is on the rise, DoD is collecting less data on troops who have high risks of health problems down the road because of them.

What they do track, via the Health Related Behaviors Survey every three years, is a small sample of troops and whether they smoke or vape.

The most recent results, in 2015, showed that vaping has overtaken smoking in popularity

“Based on the recent unexplained medical emergencies associated with e-cigarettes, we continue to urge DoD to collect information on the e-cigarette use of those whom it is accessing,” she wrote. “That way, the department will be better prepared to know the population at risk for these illnesses and assess whether it should create policies associated with e-cigarette use for both new recruits and current service members.”

Recent reports of otherwise unexplained respiratory illness in e-cigarette users have thrown local and state health departments into an uproar over the safety of the products.

The issue has gone as far as the Oval Office.

“It’s causing a lot of problems and we’re going to have to do something about it,” President Trump told reporters Wednesday after a White House meeting with health policy advisers. “There have been deaths and there have been a lot of other problems.”

Six people have so far died from lung disease related to vaping, out of 380 cases reported to the Centers for Disease Control and Prevention. Illinois reported the first death in August.

“As the risks of e-cigarette use become clearer, more data on military e-cigarette use will enable DOD and the Department of Veterans Affairs to better prepare for the costs of those risks imposed on military recruits, service members, and our nation,” Clelan wrote.