I have an own hookah right with me at home. It's actually standing beside me on my desktop atm.
Even so, I've never been to a hookah lounge.
I've been told that while it doesn't taste like it, it's more harmful for the lungs than smoking cigarettes - at least when consumed in equal amounts. (Which no one who also smokes or used to smoke cigarettes would do, but still.)
That's just hearsay though, I don't have sources or know of any studies. I personally think that smoking tobacco after being filtered through water can't be that bad. I never noticed any short term negative effects.
