Hookah was invented centuries ago for an Indian emperor when the Portuguese gave him tobacco as a gift. The royal physician advised the emperor not to inhale anything foreign, but he devised a hookah for the emperor, who could not turn down the gift.

Hookahs turned popular in India and the Islamic World. Now, they are turning increasingly popular amongst US teens, a fact revealed by an increasingly hookah lounges number in the American towns and big cities. This could be due to the fact that hookahs are perceived as a fun way to relax, socialize and meet people, even picking up chicks.

Nowadays many youngsters start smoking hookah at very early ages, like 14, even before they lay their hands on cigarettes.

Even if there is some evidence that hookahs induce aggressive forms of cancer (like lung and testicular), hookah smokers perceive it less dangerous as water would filter out a lot of toxins in tobacco smoke. But one research showed that an average session of hookah smoking lasts an hour, or 171 puffs of tobacco smoke. This is similar to inhaling the smoke of about 100 cigarettes and sometimes the session can be longer than 2 hours.

Another approach found that each puff of hookah smoke has the same level of tar and almost three times the nicotine, the addictive alkaloid of tobacco, found in cigarette smoke.

"What's worse is how hookahs are lit, with a piece of charcoal. On top of extra nicotine and cancer-causing compounds, you inhale a lot more toxic carbon monoxide." said epidemiologist Samira Asma, the associate director for the Centers for Disease Control's global tobacco program.

Carbon monoxide is a colorless, odorless gas which in chronic exposure induces severe damages, including irreversible brain injury. Moreover, hookah smoke contains three times more carbon dioxide than cigarette smoke.

What fools the consumers is that hookah smoke doesn't smell bad and doesn't leave a bad taste in your mouth. But the water does not filter anything out; it just cools the smoke down: this prolongs inhalation and contact with teeth and gums. That's why hookah smokers are five times more vulnerable to develop mouth disease than nonsmokers, while cigarette smokers only by 3.8 times.

Asma warns about a severe lack of long-term researches to detect health problems linked to hookah smoking.