natural tobbacco?

ok first of all, like someone else said before, smoke itself does not cause cancer. carcinigens do. secondly, all plants have chemicals, THC is a chemical, it's just that all of marijuana's chemicals are competley natural. and finally, i know alot of tobbaco smokers that hold their smoke in for at least 10 seconds. a common misconecption is that all pot smokers hold it in their lungs longer to get more high, but in reality, it really only needs to be held in for a couple seconds, the THC is absorbed within the first half second. alot of people that i know who smoke pot know that as well.