In June 2019, hospitals across the U.S. began seeing cases of lung injuries that were linked to vaping. Patients complained of pneumonia-like symptoms, shortness of breath, cough and chest pain, and also fever, stomach pain and diarrhea. By the following February, 2,807 cases and 68 deaths were reported across all 50 states by the Centers for Disease Control and Prevention (CDC). (That same month, the CDC stopped collecting data on these cases, in part due to a decline in cases and the rise of COVID-19.)
A majority of these cases involved THC (tetrahydrocannabinol) vaporizers, which contain the active ingredient in cannabis, yet the CDC described these injuries as E-cigarette or Vaping use-Associated Lung Injury (EVALI). Most of these vapes were likely sold on the black market, not in state-legal dispensaries, and most injuries occurred in states where cannabis is not legal for adult use, according to a 2020 review published in JAMA Network Open. E-cigarettes and legally-sold cannabis vaporizers were not likely the problem.
Thanks in part to reporting from Leafly, the CDC has narrowed down a likely culprit of EVALI: vitamin E acetate, a chemical commonly used in skin creams and cosmetics. Scientists are still asking questions about how toxic vitamin E acetate actually is when heated and inhaled. So far, all studies of vitamin E acetate toxicity have been studied in rodents or sheep, not humans, according to a February 2021 analysis in the Journal of Medical Toxicology. Another culprit could be causing these injuries, but more research is needed.
The EVALI problem has stopped making major headlines. While some cases are still popping up, deaths seem to have become more rare. Yet, many researchers are concerned about other additives sometimes found in cannabis vaporizers: phytol and pine rosin, two natural products derived from plants that may be harmful when inhaled at vaping temperatures.
