Debunking the myth that vaping causes popcorn lung

There is no evidence that e-cigarettes cause popcorn lung. In fact, all of the evidence points to the contrary.

By Michelle Minton of Reason. Excerpt:

"The persistence of the idea that vaping is directly linked to popcorn lung has prompted several health bodies, including Health Canada, the New Zealand Ministry of Health, and the UK Health Security Agency, to clarify that no evidence exists for such a link. Independent charities and research institutions, like Cancer Research UK and Action on Smoking and Health, have made similar statements. Yet, the myth continues to appear in news headlines around the world. (Credit where credit is due: The Washington Post, at least, published an article in 2019 debunking the myth.)  

These misleading headlines are being published at the same time anti-tobacco organizations are continuing to promote the mythical link between vaping and popcorn lung as a reason to support more restrictive policies on e-cigarettes. But, contrary to what frightening headlines would have you believe, there is no evidence that e-cigarettes cause popcorn lung. In fact, all of the evidence points to the contrary. 

For one thing, with the rise in popularity of e-cigarette use over the last 15 years, one would expect a concurrent increase in popcorn lung cases where the two are related. The news media periodically reports on individuals suffering from alleged vaping-induced popcorn lung, but none have been confirmed. Health authorities report no increase in bronchiolitis obliterans. Some countries’ health departments, such as Canada’s, have even admitted that there has never been a confirmed case of e-cigarette-associated popcorn lung in their country’s history. 

More importantly, if vaping nicotine e-cigarettes increases the risk of popcorn lung, one should expect an even clearer connection between popcorn lung and traditional smoking. Conventional combustible cigarettes contain diacetyl—significantly more than what was found in even early-generation e-cigarettes before voluntary industry changes and governmental prohibitions on diacetyl in e-cigarettes. 

The 2015 Harvard study, for example, found an average of nine micrograms of diacetyl per e-cigarette cartridge in the samples that tested positive for the chemical. Combustible cigarettes, meanwhile, contain approximately 336 micrograms of diacetyl per cigarette. This means that a cartridge-per-day vaper would be exposed to just nine micrograms of diacetyl, while pack-per-day smokers are exposed to more than 6,700 micrograms of diacetyl every day—750 times more diacetyl exposure than vapers. Yet, a link between smoking and popcorn lung has yet to materialize. In fact, during the initial studies of popcorn factory workers, researchers observed that those employees who reported smoking showed fewer signs of bronchiolitis obliterans than their non-smoking counterparts. 

If smokers are at no greater risk of popcorn lung because of the diacetyl in cigarettes, why would nicotine vapers be at risk of the disease when their exposure to diacetyl is several hundred times less than smokers? The answer: They aren’t."