I wonder if people get emphysema or COPD or some other kind of chronic respiratory problem just from smoking pot. I've never heard of a case. Probably hard to say since most pot smokers also smoke cigarettes.
So, which country has the most pot smokers? New Zealand, according to Nationmaster.com. Nationmaster also says cannabis use correlates with volunteering and wealth, r2=0.6-0.7. Amphetamine use, on the other hand, seems to predict exports. It's all just based on about 20 countries, but it's funny how it fell out.