"Researchers from the Mayo Clinic found the lung damage was similar to a chemical burn. "It seems to be some kind of direct chemical injury, similar to what one might see with exposures to toxic chemical fumes, poisonous gases and toxic agents," Dr. Brandon Larsen, a surgical pathologist at the Mayo Clinic in Arizona, said in a hospital press release.
The researchers looked at samples of lung tissue from 17 people, all of whom had vaped and 70% had used marijuana or cannabis oils. Two of the samples were taken from patients who died, according to the Mayo Clinic.
The accumulation of fatty substances such as oils were suspected in the lung damage, but researchers said there was no evidence they were the cause. "Based on what we have seen in our study, we suspect that most cases involve chemical contaminants, toxic byproducts or other noxious agents within vape liquids," Larsen said.
The question that remains for researchers is what those chemicals are that may be causing the injuries. More investigation into that is needed" https://edition.cnn.com/2019/10/03/health/vaping-lung-disease-chemicals/index.html