JASPER, Mo. -- Health investigators say they know workers at a popcorn plant are getting sick, but they're not sure why.
Eight workers at the Gilster Mary Lee Corp. popcorn plant in Jasper have developed bronchiolitis obliterans, a rare pulmonary disease that makes it difficult for them to breathe.
Recent lung tests showed that 12 workers had significant declines in lung function between April and August, after the company made changes to lower chemical and dust levels. On Sunday, federal and state health investigators told the workers that they're getting sick in the room where butter flavorings, soybean oil and salt are mixed. They suspect something in the flavoring, possibly diacetyl, is causing the damage to workers' lungs.
The company has begun encouraging workers to wear respirators in the room, following recommendations by the National Institute for Occupational Safety.
Since 1992, eight workers have developed the incurable bronchial disease. Four of them await lung transplants.