Below is an email I sent to a coworker after he noticed me prepping a snack of microwave popcorn. He told me his health and safety instructor warned that eating popcorn may lead to lung cancer. I was pretty sure he was mistaken and laughed him off. As I was working my way through the bag, I decided to google it just in case. You have been warned.
Clem,
Ok, I googled it and found this website:
http://lungdiseases.about.com/od/generalinformation1/a/artificial_flav.htm
This article mentions direct inhalation exposure to the butter flavorings for popcorn industry workers.
This other scarier article:
http://pubs.acs.org/subscribe/journals/esthag-w/2005/nov/science/rr_popcorn.html
mentions that the waxy coating used in microwave popcorn bags are precursors to a chemical that is a likely carcinogen. It mentions that eating a bag a week over the course of 5-10 years results in a measurable amount of this carcinogen in your blood. Although that seems to be more popcorn than a normal person (such as I) would consume, the bad news is that the FDA cannot say for sure how much of this might actually cause cancer.
So looking down at my half eaten butter flavored microwave popcorn, I'm going to have to pass on eating my third favorite evening snack and do something else to curb my evening hunger pangs--smoking.