Popcorn lung is better known as bronchiolitis obliterans. Popcorn lung destroys the small airways of the lungs leaving victims with a terrible cough and a lack of oxygen. A chemical called diacetyl causes popcorn lung and is found in microwave popcorn. Diacetyl gives the popcorn a buttery taste and is mixed in large boiling vats at factories. Factory workers stir vats of diacetyl and inhale the damaging vapors for years until they are diagnosed with bronchiolitis obliterans.
Scientists have not officially proven that diacetyl causes popcorn lung, but they are almost positive that it is the cause. Diacetyl is not only dangerous as a vapor but also as the popcorn flavoring. Studies have shown that a man who ate at least two bags of butter-flavored microwave popcorn every day for several years was diagnosed with bronchiolitis obliterans because of diacetyl. A victim of popcorn lung, Keith Campbell, was diagnosed with popcorn lung in 2002, after working at a microwave popcorn plant for two years. He said, "They tell me that I’ve got the lungs of an 80-year-old [at age 50]." Popcorn lung is very hazardous to the health of popcorn plant workers and consumers of microwave popcorn.