^ binion, that has nothing to do with CD, please keep the posts on topic.
You can get pneumonia, upper respiratory infections from any sort of lung irritation, and smoking just about anything is bad for your lungs. Pneumonia isn't contagious, so being around someone who has it isn't going to cause you to get it. It's pretty much fluid in the lungs.
Anyway, OP, the act of smoking anything in general is not good for the health of your lungs. Some have many problems, others have no problems, it's just one of those things.