Oh, the woes of modern civilization. It seems that we humans find a way to screw up just about everything, even the simplest of life's pleasures, even...popcorn! Yes, the popcorn industry was hit with a blow when the US National Institute for Occupational Safety and Health (NIOSH) determined that the "artificial butter flavor" found in most all microwave popcorn bags causes Lung Disease. The additive causes a strange abrasion of the bronchials that makes it difficult to exhale. Recommendations were issued to workers in popcorn plants like Orville Redenbacher & Act II to avoid exposure to the chemical, and ConAgra, the largest popcorn manufacturer, is planning to phase out the chemical "in the near future."
They might want to get on it sooner. The disease seems to be spreading to popcorn-loving consumers and class-action lawsuits are in the works. If you feel like you may have been infected, visit the site of Dallas-based law firm HORP&B which provides a questionnaire as well as an extensive list of the top "defective products."