U.S. health officials have narrowed in on vitamin E acetate as a "potential toxin of concern" related to recent vaping-related health issues that have killed at least 39 people. 

"We have a potential toxin of concern from biological samples in patients," Centers for Disease Control and Prevention Principal Director Dr. Anne Schuchat said on Friday. "We are in a better place than we were a few weeks ago in terms of finding a culprit." 

The compound used in supplements, cosmetics and some vaping products was detected in all 29 lung tissue samples from patients health officials tested, Schuchat said. THC, the active ingredient in marijuana, was found in 23 of the 29 samples tested, while nicotine was found in 16 samples.

.@CDCMMWR compares adult use of e-cigarette, or vaping, products in IL between patients w/ lung injury & individuals w/o lung injury. Findings reinforce recommendations not to use products containing THC, esp. those obtained from informal sources. https://t.co/vuzBR4e0Aw pic.twitter.com/8UxSSnh8an

— CDC (@CDCgov) November 8, 2019

The findings may be seen as somewhat positive for e-cigarette maker Juul, partly owned by tobacco giant Altria Group (MO - Get Report) , which earlier this week announced that it is halting all sales of its popular mint flavor in the wake of two studies showing the company's role in a dramatic spike in teen use.

Studies published Tuesday in the Journal of the American Medical Association found that more than half of teens who vape do so with a Juul product, and that mint was the most popular flavor. Juul said it made the decision to pull mint in light of the results.

In its quarterly earnings report last week, Altria said it recorded a $4.5 billion pretax charge to cut its $12.8 billion stake in Juul by a third, citing the Trump administration's plans to remove flavored e-cigarettes from the market, as well as e-cigarette bans that cities, states and countries are putting into effect.