NEW YORK (AP) — Health officials said Tuesday they have more evidence that a certain chemical compound is a culprit in a national outbreak of vaping illnesses.

Researchers analyzed black market vaping cartridges seized in Minnesota during the outbreak this year, and vaping liquid seized in that state last year. The newer cartridges contained the compound vitamin E acetate, but none of the older samples did.

They also looked at vaping cartridges collected from a dozen patients. Vitamin E acetate was commonly found in those, too.

The study was small, but it echoes other work that found the compo...