...California food-flavoring workers recently diagnosed with bronchiolitis obliterans, a rare and life-threatening form of fixed obstructive lung disease. Also known as popcorn workers lung, because it has turned up in workers at microwave-popcorn factories, the disease destroys the lungs. A transplant is the only cure.
Granted, the amount of artificial butter flavor (diacetyl) they work with is probably more than the average person is ever going to encounter. But I believe it's good to minimize ingestion of bizarre chemicals whenever you can.
Did you know you can pop plain kernels in a brown paper bag? We learned this method from Alton Brown on the Good Eats episode Ear Apparent. This is pretty much the only way we eat popcorn now at home (or if we bring some, at school). The secret to brown bag popcorn:
Put about 1/4 cup of popcorn in a small paper lunch bag. Fold the top and staple closed. Microwave! Voila!
AB suggests olive oil, kosher salt, and seasoning, but I've found that the olive oil gets the bag greasy and isn't necessary. You can fiddle a bit with the amount of popcorn and microwave time, but as evidenced by the photograph, 1/2 a cup seems to be too much. If you want more flavor, something I have found effective is to spray a bit of olive oil on the popcorn after it's been popped, sprinkle in some kosher salt, and shake up the bag. Less messy all around.
Try the brown bag popcorn. It's better for you, and the texture compared to the other stuff (movie popcorn included) can't be beat.