The plant has nothing to do with it? Its just the smoke? What the hell do you think is in the smoke? Do you even understand combustion? It doesn't neutralize and make all burning matter into the same "smoke" and inhaling marijuana smoke doesn't have the same cancer risk as some other smoke, it depends on what's burning.


Burning wood? That smoke isnt as bad, but you shouldn't breath it in that much anyway, now cigarettes and marijuana? That's burning all the chemicals and pesticides and poisons and crap the companies that manufactur the cigarettes make, and even just the marijuana tobacco is still bad, it still leaves tar, it's still burning the leaves and flowers, it's still in the smoke.
Of course there's plenty of worse smoke fumes to breath in than just marijuana and tobacco.