A new study by a Colorado lab points to a new potential culprit in the nationwide wave of lung injuries caused by vaping: a rare disease caused by inhalation of a chemical present in many cheap vape pens that is used to fuse metals together.

The study used data from 53 patient cases in Wisconsin and Illinois who suffered severe lung illness due to vaping. From that study, the lab concluded that the vaping illness symptoms directly correlate to an advanced stage of a very rare disease, almost exclusively suffered by welders and others who inhale chemical concoctions, called Metal Fume Fever.

The advanced stage of Metal Fume Fever, which the lab believes are the equivalent of the vaping illnesses, is called Cadmium Pneumonitis.

The culprit chemical, according to the lab? Silver solder, which helps binds metals together in many cheaply manufactured vape pens, which contains the chemical cadmium. When inhaled, cadmium oxide fumes are highly toxic to organs, and according to the study the fumes "directly injure lung cells, leading to fluid accumulation, impaired lung function, and respiratory failure."

Silver solder is used to "make stable unions between dissimilar metals such as copper and stainless steel," the study reads. The appeal of lower-end vape pen manufacturers using silver solder is its low price: "Cadmium-containing silver solder is less expensive than cadmium-free alternatives and has improved flow properties which facilitate the joining of dissimilar metals found in vape pen electrical components," the study reads.

The study, conducted by the Colorado Green Lab , is the latest evidence as health officials try to solve a wave of lung illnesses—including two deaths in Oregon—linked to vaping.

Several high-profile studies have come to different conclusions. While some have blamed black market cartridges and possible cutting agents like vitamin E acetate causing oil build-up in the lungs, others have likened the lung injuries to chemical burns.

Last week, Gov. Kate Brown implemented a six-month temporary ban against all flavored vaping products. The ban restricts all additives and flavors in cartridges including artificial flavors and botanically-derived terpenes. The ban will take effect within the week.

The new Colorado study suggests that Oregon's ban on flavored cartridges won't slow the wave of vaping-related sickness—because the source of the illness is the vape pens themselves, not the oils inside.

But if the newest study from the Colorado Green Lab holds any bearing, Gov. Brown's flavor ban will have missed the mark.

But Susan Pinnock, a nurse who spoke on behalf of the Oregon Nurses Association, says she's read all the research—and isn't convinced the illnesses are being caused by just one culprit. If hardware is found to be the issue, she says, it won't mean that Brown's flavor ban is pointless.

“I feel like [the ban] still holds validity, because again we’re trying to reduce the risk and harm. A lot of the kids aren’t going to use if there’s no flavor,” Pinnock says. “The flavor ban is just going to help reduce the kids’ access.”

Pinnock also thinks it will take longer than six months to identify the source of illness—and if chemicals in the hardware is a factor, then she says Brown should consider an all-out ban on vaping.