Three full joints a day equals the tar from 20 cigarettes a day. Folks, the methodology in these studies is as flawed as the methodology in the UCLA studies I participated in in the mid '70's.
Almost NO ONE smokes three full joints themselves a day. No one I've ever known well, even back in the day, did. People pass and share, you know, or they use a one hitter or pipe. Using that "three full joints a day" as a benchmark is just plain ignorant BS.
In the UCLA studies in which I participated (six of us at a time lived there for 94 day under completely controlled conditions), EACH JOINT was the size of a commerical 100mm cigarette, with more weed where the filter would be. No one rolls Buffalo bombers that big! Each of us had to smoke that joint fully ourselves, without passing -- that was considered one dose. Folks, that is BULLCRAP!
Even back then, you could get ten people reasonably high on the amount of weed in what they considered a one person, one time dose.
These days, I don't smoke the amount of weed in three of those cigarettes in three months (or more) time, yet I would have to smoke that much each day, every day, to do the damage that a pack a day ciggy habit causes to my lungs.
The methodology of these researchers is so fundamentally flawed, so ridiculously and pervasively flawed, (I could tell you in depth about the lame bs from the study I was in) that there findings bear no resemblance whatsoever to the truth.
When people have to lie to make their point, you know something's up.