If you are exposed to asbestos, does it guarantee that you will develop mesothelioma, or do you have to smoke too?

Well posed ?'s! Not all that are exposed get meso, in fact very few. No "dose response", meaning those heavily exposed ma not get it; other's washing their miner husband clothes do...Lag time is long: 20-30 years; and smoking and asbestos do seem to co-conspire to cause both lung and mesothelioma. There are cases with no known exposure to either, and some with just asbestosis.