Seriously, this is getting tiring. One of the causes of BO is diacetyl which is used in huge concentrations in popcorn factories. People in the factories contracted the rare disease BO from the diacetyl. So it acquired the coloquial name popcorn lung. There are other things that cause BO. They also are causes of popcorn lung, because it’s the SAME THING. As far as the other causes, they’ll probably not use the phrase popcorn lung because it wouldn’t make sense since these people didn’t catch it from working in a popcorn factory. In Scotland some people call influenza the lurgy. That doesn’t mean it’s any different. Similarly some people call chlamydia the clap. BSE is also known as mad cow disease.