The recent epidemic of vaping-related illnesses closely resemble injuries suffered by victims of mustard gas attacks and chemical factory accidents, according to new research from the Mayo Clinic.

Authorities have so far, pretty troublingly, been unable to identify the cause of the illness which has caused hundreds of known vape-users to be hospitalized and at least 16 to die from respiratory failure. A few weeks ago, an investigationreported by the New York Times turned up one suspect: Vitamin E thickening agent used in cannabis oils.

But the new study from the Mayo Clinic didn’t find any accumulation of the oil in patients it studied.

What they did find were immune cells known as macrophages which had turned white and foamy. This is a symptom closely tied to exposure from chemical burns, leading researchers down a new path.

“So maybe we need to look more closely at the chemical compounds, and not just oils, but the chemical constituents, to figure out which ones are injurious,” Dr. Brandon T. Larsen, a surgical pathologist at the Mayo Clinic, told the New York Times.

The samples that Larsen and his colleagues looked at came from 13 men and for women between the ages of 19 and 67.

“All 17 of our cases show a pattern of injury in the lung that looks like a toxic chemical exposure, a toxic chemical fume exposure or a chemical burn injury,” Larsen said.

Larsen went to compare the burns to those seen in World War I soldiers who endured mustard gas attacks and victims of chemical accidents.

“To be honest, they look like the kind of change you would expect to see in an unfortunate worker in an industrial accident where a big barrel of toxic chemicals spills, and that person is exposed to toxic fumes and there is a chemical burn in the airways,” he added.

Larsen’s sample size, like that of the study of vitamin e in vape cartridges, was relatively small, and it may be awhile before anyone can be creation what is behind the vaping illness. Larsen said he believes that cases may have gone unreported for quite some time before the explosion in the news of recent months.

Photo via Flickr user Vaping360