Quote Originally Posted by DRybes
A study once showed that tobacco through a hookah, during a half hour session, delivered the nicotine equivalent of 3 cigarettes, and the tar equivalent of 30 cigarettes. Hookahs are not designed for inhaling as far as safety goes, you just taste the smoke like with a cigar or pipe.

The smouldering charcoal has a more potent carcinogen than other tobacco forms. I'd use the hookah without charcoal for weed only, like a hosed bong.
To be fair, that study was highly criticized for methodologies employed. Well, maybe we're talking about different studies.

Research suggests that a session of hookah tobacco smoking (tobacco molasses) which lasts 45 minutes delivers slightly more tar and carbon monoxide (around 5-10%) than a packet of cigarettes. This study has, however, come under criticism for using unrealistically high temperatures for the tobacco (600-650 degrees C) and using arbitrary figures for tar filtration rates.