Someone posted earlier bout cancer and smoking ganja, I found this in a magazine:
( Pot smoke cleared of cancer link)
Dr. Donald Tashkin has been studying the effects of marijuana on the respiratory system for decades and is cited as the source of dire claims that marijuana is more dangerous than tabbaco smoke. However, his latest study is not likely to garner much attention from the anti-cannabis propaganda machine because it decisively refutes the assertion that marijuana smoking leads to cancer.