marijuana vs. tobacco, which is more harmful for lungs?

[barret]

I believe a bong(water bong) is safer to smoke out of because the water filters out some harmful products in the smoke.

-peace

That is true, but there have been reports that the amount of hits people take from bongs increases because each hit lacks the amount of potentcy as smoking out of a pipe or joint would, thus causeing the user to smoke more ( of harmeful and non harmfuel chemicals) to ge the same effect.