Election Section

SIOUX CITY, Iowa — A popcorn plant worker has been diagnosed with a rare lung disease that health authorities have linked to inhaling the artificial butter flavoring used in microwave popcorn. 

Federal health officials are testing other workers at American Pop Corn Co. for bronchiolitis obliterans, also known as popcorn packers’ lung, a severe and irreversible disease. 

The man, who was not identified, still works at the plant. He has a “light case” of the disease that is not life-threatening, company vice president Tom Elsen said Monday. He no longer works in the department where butter flavorings are mixed with other ingredients. 

Elsen said the man’s condition was discovered when a federal health team visited the plant last year after eight popcorn workers in Missouri were sickened by the disease, prompting a national investigation. 

The disease is caused by inhaling damaging amounts of chemicals such as chlorine or ammonia, according to the Centers for Disease Control and Prevention. A chemical called diacetyl in the butter flavoring of popcorn may be the cause of the illness found in the popcorn workers, the CDC said in an April report. 

The disease kills cells in the bronchial airway tubes in the lungs and causes scarring, which makes breathing more difficult. 

The CDC says scientists have found no evidence of danger to people who eat microwave popcorn.