the stupidity here is amazing. no they do not add rat poison or fibreglass to cigarettes. they do add some chemicals in order to make the cigarette burn faster. all-in-all, you are inhaling burnt material into your lungs. its not good for you...
which is my next point. weed isn't good for your lungs either. it may not have the carcinogens, but it has a shitload more tar. I could go back to smoking (1-5 cigs a day) like I used to, and my lungs would still be in better shape than the potsmokers posting here because I have a vaporizer and I rarely smoke weed these days.
like motumbo said, cigarettes give you a buzz. they are relaxing. I am not promoting cigarettes, but there is a reason people smoke them. not just "they are addicted." or they're stupid. anyways, if you want a totally safe cigarette, check out the njoy. I'll post about it in another forum that deals with this kinda shit, one without all these fools.