The more federal authorities investigate dangers associated with vaping, the more we discover how much we do not know about the dangers of this suddenly popular habit.

The Centers for Disease Control and Prevention recently revealed that its investigation into the serious lung conditions related to vaping that began emerging last year have been largely traced to E acetate, a chemical compound found in THC vaping products. Of the nearly 2,000 cases of vaping-related lung illnesses reported through early this year, 82% of patients said they had used THC vaping products. A little more than one-third of the patients said they exclusively used THC vaping products.

More alarmingly, many of the patients reported using noncommercial vaping products. In other words, they were not buying name-brand, commercial vaping products that can be regulated by authorities. Instead, they may have been sickened by homemade or illicit vaping products.

In response to the lung illnesses that began showing up last year, many states and local governments banned the menthol and fruit-flavored vaping products that experts contend are most likely to attract — and hook — young people. Though it may not directly address the issue of dangerously formulated black-market vaping products, it is still a solid strategy for protecting young people from a dangerous habit.

Vaping among America’s young people is increasing dramatically in just a few short years. Early data from the 2019 National Youth Tobacco survey indicates that more than 5 million American youths report that they have used vaping products in the last month. That’s up from 3.6 million in 2018.

E-cigarettes are such a new product that federal authorities did not even begin asking youths about their vaping habits on the survey until 2016.

Like the sale of the products themselves, research into the long-term health effects of e-cigarettes has only gotten started, and the effects remain unknown.

The rate at which we learn the true dangers of vaping — for adults or teenagers — does not seem to be keeping pace with the growing popularity of e-cigarettes. And the dangers posed by illicit or homemade vaping products remain even harder to understand.