It is not just the act of smoking that creates the carcinogenic effects of marijuana. Hookahs, vaporizers, and brownies may all decrease the amount and potentcy of the carcinogens, but they are still there. Just as Ultra Light cigarettes contain less carcinogens than, say Pall Mall unfiltereds, the Ultra Lights still contain carcinogens.
However, you are correct that there is little to no evidence that THC alone is a carcinogen. Of course, there is little to no evidence that nicotene alone is a carcinogen (although, in all honesty, it appears it may be metabolized in the body as a carcinogen, but the medical jury is still out). It’s the way that these substances are grown, packaged, and, yes, used that increase the likelihood of carcinogens. I certainly think that the fact the substance, as used by a vast majority of users, is carcinogenic is an argument for it’s dangerousness and potential regulation.
Actually, I don’t find the argument illogical at all. Injesting marijuana is bad for you. The fact there are other things that are legal and are bad for you does not change that fact. Now, if you’re arguing that every single substance in the world, from pot to meth to X to cocaine to Oxycontin to PCP to any prescription medication, should be available for a person to decide to use (which is certainly an argument made here), you accept the fact that there should be some regulation as to what people should have at their disposal. The question then becomes, where are you going to draw that line. Very well-educated, rational people differ on where that line should be drawn. Personally, I’d include marijuana on the regulated side. Of course, looking now at the societal costs throughout the history of the U.S., of alcohol and tobacco, I may very well put those on the regulated side too. However, that isn’t going to happen anytime soon. Well, maybe for tobacco.
All in all, I guess I kinda come down with King’s Gambit and the benefits I see from marijuana use and it’s legalization are outweighed by the costs. Why add more problems to a world that is already rife with them from alcohol and tobacco. Now, if I were to create my own country (lets call it Hamletland), without all the history and social influences in the United States, I would very seriously consider making alcohol and cigarettes illegal and making thc legal. However, I’m dealt the world I live in, and make my judgments accordingly.