Bronchiolitis obliterans, an irreversible lung disease, first attracted attention 16 years ago when it was diagnosed in a handful of workers at a microwave popcorn processing plant in rural Missouri. The disease, now referred to as “popcorn lung,” has been linked to diacetyl exposure. The disease happens when the smallest airways of the lung become scarred and restricted. The only treatment is lung transplant.
David Egilman, a doctor and clinical professor of family medicine at Brown University in Providence, R.I., said of the disease, “It’s like you’re drowning all the time.”
Diacetyl and its substitute, 2,3-pentanedione, is a flavoring agent that is used in many products such as microwave popcorn flavoring, flavored coffee, baking products, and many more. People who work at coffee roasters are at risk for exposure, as well.
“It’s so important when somebody is working in a facility with flavoring chemicals like diacetyl or 2,3-pentanedione, if they have any respiratory symptoms at all – cough, shortness of breath or wheezing – they be removed from exposure until they’re evaluated,” said Rachel Bailey, medical officer in the NIOSH Respiratory Health Division. “Because if they have this disease, it doesn’t improve. We don’t want it to get worse over time.”
“The exposure is much more widespread than we thought initially,” said Dan Morgan, head of the Respiratory Toxicology Group at the National Institute of Environmental Health Sciences in Research Triangle Park, NC. “Any industry where the flavorings are mixed or heated can result in higher exposures. They’ve been looking at more and more different industries, and they’ve seen exposure in a lot of places where they haven’t really looked before.”
Diacetyl and 2,3 pentanedione has also been found in e-cigarette flavorings, as well, putting vapers at risk of the disease with every pull.