Vaping deaths and lung illnesses could be triggered by toxic chemicals, not oils lodged in lungs as many had previously thought, a study released Wednesday suggests.

The research further complicates the national effort by medical experts to unravel the source of a vaping illness epidemic that has struck at least 805 people in the country, including eight in Oregon. Two of 13 deaths tied to vaping were in Oregon.

The new study, published in the New England Journal of Medicine, looked at 17 lung illness cases at Mayo Clinic branches in Arizona, Minnesota and Florida. Some of the victims involved in the study were hospitalized in September. Two were hospitalized in 2016 and 2017.

All of the patients in the study had vaped in the 90 days before they had symptoms and all had what appeared to be acute lung injuries. Two of the patients died. Of the patients the doctors had information for, 12 vaped cannabis oils and two said they vaped nicotine to quit tobacco.

When the doctors looked at samples of the patients’ lungs under a microscope, they saw that the lungs had filled with white blood cells and fluids, causing severe breathing problems. That reaction is what doctors typically see when patients have a toxic reaction to medications or to “noxious chemical fumes,” the doctors wrote.

None of the patients had oil droplets in their lungs, the doctors found.

But the researchers couldn’t say what specific chemicals were triggering the patients’ reactions.

“Vaping products,” they wrote, “allow the user to aerosolize essentially limitless combinations of chemicals.”

Vape juice can contain contaminants such as polycyclic aromatic hydrocarbons, a byproduct of burning coal, oil and gas, the doctors wrote.

According to the researchers, other doctors may have been relying on oil-detection tests when trying to diagnose vaping-related lung illnesses. The results of this study show that such tests might be inadequate when looking for a diagnosis, the 14 Mayo Clinic Doctors and PhDs wrote.

A study last month by the U.S. Centers for Disease Control and Prevention concluded that oil in the lungs of five North Carolina patients caused massive inflammation and lung injuries. The patients all had vaped marijuana not long before showing symptoms, the study said, and all had oil droplets in their lungs.

Vitamin E acetate is one chemical cited by federal officials as a possible culprit. The chemical is sometimes found in liquids used to dilute vape juice. Because of how hot it has to get before it turns into vapor, the chemical can turn back into a liquid before the lungs have a chance to absorb it into the blood stream.

The federal government said last week that cannabis vape juice was the most common factor among the 514 severe lung cases investigators analyzed. Most of the vape juice cartridges were bought off the street, officials said, making some of Oregon’s cases stand out: At least five of the eight known victims bought products at legal marijuana retail stores, state officials have said.

The state last week proposed a six-month ban on vaping products – including e-cigarettes, nicotine cartridges and marijuana cartridges – in response to Gov. Kate Brown’s demand for steps she could take to curb the epidemic in Oregon. The Oregon Health Authority also proposed expanding public education and making it easier for people to get help quitting tobacco and e-cigarettes.

The governor’s office hasn’t said when Brown will be ready to make a decision. A potential ban on tobacco products would first have to be reviewed by the Oregon Department of Justice.

The local epidemic is unlikely to end soon. More Oregon deaths and illnesses are likely, public health officer Dr. Dean Sidelinger said last week.

-- Fedor Zarkhin

fzarkhin@oregonian.com

desk: 503-294-7674|cell: 971-373-2905|@fedorzarkhin

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