Principal investigator Thomas Eissenberg of Virginia Commonwealth University says that in a hookah, tobacco is heated by charcoal, and the resulting smoke is passed through a water-filled chamber, cooling the smoke before it reaches the smoker. Some waterpipe users perceive this method of smoking tobacco as less harmful and addictive than cigarette smoking.

However, waterpipe and cigarette smoke contains some of the same toxins -- disease-causing tar and carbon monoxide, as well as dependence-producing nicotine, Eissenberg says.

Additionally, the exposure to these toxins through waterpipe smoking may be greater due to longer periods of use. Smokers take more and larger puffs with waterpipes, leading to inhalation of 100 times more smoke from a single waterpipe use episode relative to a single cigarette, Eissenberg explains.

The study, published in the Journal of Adolescent Health, finds that about 43 percent of those surveyed had smoked tobacco using a waterpipe in the past year; and 20 percent of them had smoked tobacco using a waterpipe in the past month.