It seems logical that smoking weed could lead to lung cancer. The American Lung Association says pot smoke has more carcinogens than cigarette smoke. Pot smokers also tend to inhale more deeply and hold the smoke in their lungs longer than tobacco smokers do, which increases the lungs' exposure. But the evidence, at this point, doesn't seem to back up the theory. A large study in 2006 found no link between weed and lung cancer. Surprising the UCLA research team, whose members expected to find a correlation. - CBS news
