Re: cigs vs. hookah.
The thing that really makes me think these studies are bogus is the whole bit "as much tar as 100-200 cigs". Ok lets say hookah is worse for you, fine maby it is maby it isn't, but 200 cigs, there is not enough tobacco in the bowl to equal 5 cigs. Even if you incinirsted the bowl of shisha and inhailed every bit of the substance you still would not be able to match the volume of tobaco in say 10 cigs. You cant deny physics.
And the tobacco is not even burnt its roasted, so you are not inhaling the whole of the substance, a good amount remains unlike in cigaretes.
Now the bit about heavy metals in the coal i belive, and i think it may be the most harmfull part of smoking hookah.