I'm a non-smoker...
As a general rule I don't mind smoking. Just as long as I'm not intoxicated in the fumes or something.
Everybody knows what effects that smoking has on your health, and if they don't mind running the risk then go for it. It's like alcohol as well. Okay I know maybe it's not as severe... but many an accident is caused by being 'drunk'.
We all know the dangers, and it's all in our control. If taken under moderation it should be alright. But of course I don't know xD.