Sept. 6, 2007 -- Many people love the buttery smell of microwave popcorn, but the savory aroma has recently been linked to a lethal lung disease in factory workers who make the popular snack.
Now, the first-known case of the illness has turned up in a man who consumed large amounts of popcorn. Popcorn fanatic Wayne Watson ate about two bags daily, but now he has quit because of the havoc it reeked on his lungs.
Watson had all the symptoms of a rare disease dubbed "popcorn lung," which derives its name because it was found in popcorn plant workers exposed to a flavoring ingredient called diacetyl. Diacetyl is a natural substance heated in a factory setting to give microwave popcorn its buttery taste.
While Watson initially didn't recognize the symptoms as popcorn lung, when he began speaking with a doctor who had done research on the disease, she suspected he might be suffering from the disease.
"She said, 'Are you ever around butter-flavored microwaved popcorn?' I said, 'I am microwave popcorn,'" Watson said.
Cecile Rose of the National Jewish Medical Center in Denver had studied the disease and wondered whether there was a consumer connection. She knew the symptoms.
"The very small airwaves called the bronchials become blocked by scar tissue and inflammation," Rose said. "You cannot blow air out."
The disease normally affects popcorn factory workers who inhale large amounts of the chemical's fumes. Some workers have died from it and many have needed lung transplants to survive.
To determine whether Watson had the same disease, Rose sent an industrial hygienist to Watson's home and he made a startling discovery.
"In your home microwave, you're seeing similar levels [of diacetyl] to what we've seen in microwave popcorn manufacturing plants," industrial hygienist Michael Van Dyke told Watson.
Even before Watson's case became public, the popcorn industry had started taking swift action.
Last week, Indiana-based Weaver Popcorn became the first company to announce it would remove the flavoring ingredient from its product.
"There had been such a consumer response that we felt it necessary to actually inform consumers that we had made the change," Weaver Popcorn CEO William Weaver.
And though the industry pointed out massive amounts of diacetyl are involved in the cases and their products remain safe, on Wednesday three more companies that produce some of nation's most popular brands said they'd change their formulas too.
Consumers can expect the change to arrive on store shelves in the next year.