I have smoked nearly daily since I was 16 and have never smoked cigarettes. When I turned 30 last year I had a checkup on my lungs that revealed that I have ZERO lung damage after all this time. I attribute this to my active lifestyle and the fact that we don't really fully understand the effects that marijuana has on our bodies. I am a card-holder in my state and I fully support the legalization of all drugs for many different reasons.