http://www.menshealth.com/health/does-smoking-pot-cause-lung-cancer It doesn't matter what kind of smoke you put in your lungs you can still get lung cancer from it. Sure smoking a cigarette has more chemicals but if you smoke weed it still is smoke going into a part of ur body that isn't supposed to have smoke in it. Many research says it causes cancer and some say it doesn't, this is because researchers don't quite understand it. It is still proven that smoking weed has proven to be very unhealthy. If there are any weed smokers reading this I encourage you to stop smoking weed, it still damages ur lungs. There are many ways to get MJ in you. Eat it, put a weed patch on, spray it on you. Anything but smoking it.