A Heating Element, Not Vitamin E Acetate, May Be the Primary Factor in EVALI Cases, Study Says
E-cigarette devices with nickel-chromium heating elements may be linked to a significant risk of lung injury, say researchers from the University of California, Irvine, (UCI) School of Medicine and the Huntington Medical Research Institutes.
During a new animal model experimental vaping study, the researchers noticed that these devices were consistently resulting in cases of vaping product use-associated lung injury (EVALI) – even without the presence of nicotine, THC, or vitamin E acetate, all previously considered to be contributing risk factors.
The researchers’ early findings have now been published in the Journal of the American Heart Association.
Early results question previous EVALI assumptions
In the fall of 2019, the United States witnessed a sharp and significant uptick of EVALI cases. Reaching a peak in September 2019, the “vaping crisis” led to 2,807 hospitalizations, including 68 deaths.
An investigation from the US Centers for Disease Control and Prevention concluded that vitamin E acetate was “strongly linked to the EVALI outbreak,” but noted that the extent of the investigation at the time meant that it was impossible to fully rule out other compounds of interest, such as THC.
Still, vitamin E acetate remained the prime culprit behind the lung injuries, and some states went so far as to introduce bans on vitamin E acetate in all vape products. But according to this new research, the vitamin oil might not be the greatest concern after all.
“The results were so impactful, we felt it imperative to release the initial findings early so that electronic cigarette users could be cautioned sooner, especially considering E-cigarette users are at increased risk of Covid-19,” senior author Robert A Kloner, MD, PhD, chief science officer for HMRI and professor of medicine at USC, said in a statement.
Equipment swap led to the surprise discovery
The researchers had originally set out to perform a larger study on the general effects of vaping and e-cigarette use on the cardiovascular system. The experiments began with the researchers using a vape device with a stainless-steel heating element, but after the device was discontinued the researchers switched to an alternative. This alternative device was completely compatible with the original system the researchers had been using, the only difference being that it used a nickel-chromium alloy as a heating element.
“Within an hour of beginning an experiment, we observed evidence of severe respiratory distress, including labored breathing, wheezing and panting,” said Michael Kleinman, PhD, professor of occupational and environmental medicine at UCI School of Medicine and member of the UCI Center for Occupational and Environmental Health.
“After analyzing lung tissue from subjects in the study, we found them to be severely compromised and observed other serious changes such as lung lesions, red blood cell congestion, obliteration of alveolar spaces, and pneumonitis in some cases.”
In the previous almost-year of research, none of the study subjects exposed to vapors from the stainless-steel devices developed any respiratory distress on this level. One had experienced slight lung inflammation, but the researchers report this only affected less than 10 percent of the area of the lung. Only after the switch to the new nickel-chromium device were problems of this scale reported.
EVALI research moving forward
After further experimentation, the researchers determined that the lung injuries occurred with nickel-chromium device use even without the present of nicotine, THC, or vitamin E additives. They also note that the injuries could be related to differences in wattage and power settings between the two device types, and that this should be a target area for study in future follow-up investigations.
“While further research is needed, these results indicate that specific devices and power settings may play a key role in the development of EVALI as much as the additives do,” said Kloner. “The harms associated with e-cigarettes and vaping simply cannot be overstated.”
Outside of the risk of EVALI, vaping and e-cigarettes have been linked to other harms. Recent studies on vape product safety have uncovered dangerous amounts of lead in some older disposable vape cartridges, raising further questions for the e-cigarette industry.
“Even if the culprit for these vape related injuries turns out to be, say, vitamin E, it doesn't mean we should take stop focusing on the other potentials,” Dr Graham Wood, the chief scientific officer at Neptune Wellness Solutions, told Analytical Cannabis at the peak of the EVALI outbreak last year. “We need to keep our eyes on all the potential issues.”
“We have to look at the construction of the devices, the coils, what's used, whether it's a bare metal coil versus a ceramic heating element,” Wood advised. “I think all those things need to be taken into account.”