that's not true at all. cannabis smoke contains around 3x the amount of tar found in tobacco smoke and 50 percent more carcinogens. also a lot more of it is getting into the lungs because a lot of joints are hand rolled and without filters. the one thing going for cannabis smokers is that they tend to smoke less than tobacco, but comparing head on, it's no comparison, it is worse. now as a doctor, i do find marijuana an intriguing topic as i believe there is credible evidence for symptomatic effects, but to ignore the consequences is just pure ignorant. i am aware there are many ways to consume marijuana, but even still there are so many s*** effects, you can't dismiss it as being safe.