Putting a Crimp in the Hookah

http://www.nytimes.com/2011/05/31/health/31hookah.html

In fact, because a typical hookah session can last up to an hour, with smokers typically taking long, deep breaths, the smoke inhaled can equal 100 cigarettes or more, according to a 2005 study by the World Health Organization. 

That study also found that the water in hookahs filters out less than 5 percent of thenicotine. Moreover, hookah smoke contains tar, heavy metals and other cancer-causing chemicals. An additional hazard: the tobacco in hookahs is heated with charcoal, leading to dangerously high levels of carbon monoxide, even for people who spend time in hookah bars without actually smoking, according to a recent University of Florida study. No surprise, then, that several studies have linked hookah use to many of the same diseases associated with cigarette smoking, like lung, oral and bladder cancer, as well as clogged arteries, heart disease and adverse effects during pregnancy. And because hookahs are meant to be smoked communally — hoses attached to the pipe are passed from one smoker to the next — they have been linked with the spread of  tuberculosis, herpes and other infections.