Broncheolitis obliterans, also known as “popcorn lung disease” is apparently a new kind of medical illness.

The first consumer case of “popcorn lung” was discovered in Denver, Colorado, where a 53-year-old man who has been eating three bags of microwave popcorn a day for the past 10 years was rushed to the hospital after complaining throat pains.

The effect of “popcorn lung” is the permanent scars it leaves on the airways and tracheae, making it very hard to inhale and exhale.

The first known contact with this disease was reported in microwave  popcorn flavoring and packaging factories. As opposed to the workers in these factories, officials assured  consumers that they  were out of harm’s way due to relatively low exposure to butter-flavor fumes and powders.

Apparently they were wrong, and after treating the man, a furniture salesman, earlier this year, a doctor at National Jewish Medical and Research Center sent letters describing the case to four federal regulatory agencies.

“We cannot be sure that this patient's exposure to butter-flavored microwave popcorn ... has caused his lung disease," wrote Dr. Cecile Rose. "However, we have no other plausible explanation.”

The Flavor and Extract Manufacturers Association on Tuesday recommended that members who make butter flavors with diacetyl, the chemical suspected to be harmful, consider cutting its concentration in flavors. However, the association made clear that the new information does not suggest any risk from eating popcorn.

"No, it's inhalation," Dr. Rose said. "This patient described enjoying the smell so much he was actually inhaling the steam."

Dr. Rose's July letter to the Food and Drug Administration was posted Tuesday on The Pump Handle, a blog maintained by David Michaels, a professor at the George Washington University School of Public Health.

She also wrote to the Environmental Protection Agency, the Centers for Disease Control and Prevention, and the Occupational Safety and Health Administration.

The Food and Drug Administration (FDA,) which is evaluating diacetyl's link to lung disease, is considering the Colorado case, spokesperson Mike Herndon said.