Problem, however, is that eventhough "you do it because you want to do", you also drag people that don't want to down with you. Smoking doesn't just tackle yourself, it tackles those around you, as the smoke you exhale is as bad (if not worse) as the smoke you inhale. So your decission to smoke puts others in danger.
I'm not sure about as worse your lungs pick up all the crap from the smoke, probably filtering it even more, but what is filtered is probably minimal.
That being said, if you smoke, be conscientious about it. Even if it were perfectly safe for those around you, nobody likes the smell. If smokers smell it on you, it's likely that they will want to burn one soon after as well. Our rival college about an hour or so away has put a ban on smoking on campus, and if it starts to happen here, I'm likely to push for it as well, so long as staff here can at least get a smoking area or two set away from where a lot of people walk.
It's my body, I'll do what I want with it, but that's no reason for me to cause others discomfort with my nasty habit.
I smoked from age 11 or 12 to 15 or so, then quit. I liked smoking, but decided it wasn't worth it. Everything tastes a lot better when you don't smoke. Smoking always relaxed me (which is contradicting to the fact that cigarettes are a stimulant, but still). I went cold turkey overnight. I still think about it now and again, but I never get cravings. I don't think I'll smoke again, or if I do, it won't be for a long time.
I've got a lot of friends who argue with me about it being a stimulant. It is. It's just that when you're addicted, you tend to go through slight withdrawals when you don't smoke for a bit, compounding or creating any stress you're having. Lighting up gets rid of that.
