Originally Posted by hazetwostep
you don't consume any carcinogens from eating except if there were chemicals used on the plant or on the soil containing them. marijuana itself has positive nutritional values when ingested.
vaporizing eliminates the vast marjority (95% i believe) of carcinogens, not to mention that it is tar-free, when used properly. it however does not release all the different kinds of cannabinols present, though it does release the main one that is attributed for causing the desired effects (delt-9-tetrahydrocannibinol).
ice in the bong technically is a less healthy smoke, but is nice as it is easy on your throat. it is less healthy because it allows you to pull more smoke in, resulting in more tissue irritation. it allows you to hold it longer, also leading to more irritation. it also causes parts of the lungs to contract, pulling in more THC as well as carcinogens. water in general also strips the smoke of some THC, which sucks to lose! haha
there are a couple other negative aspects that have been suggested by research that i cannot recall right now as my mind has shutdown to recharge after this semester.