“Popcorn lung” is an irreversible scarring of the smallest airways in the lungs. It’s caused by inhaling vapors of a buttery-tasting chemical that some manufacturers may be adding to their microwave popcorn.
Diacetyl is a natural compound found in cheese, butter, yogurt, and wine. It’s not harmful when swallowed, but it can damage the lungs if large amounts are inhaled. Nearly all “popcorn lung” victims worked in popcorn or flavoring manufacturing facilities, where they breathed in the chemical every day. The most severe cases needed lung transplants.
Several consumers also claim to have popcorn lung, including a middle-aged man in Colorado who inhaled the buttery steam from the two bags of popcorn he microwaved every day for 10 years “because it smells good.” His $7 million award is being appealed by the supermarket chain that sold him the popcorn.