Although many college students believe that smoking tobacco through a hookah is safer than cigarettes, a growing number of legislators, college administrators and health groups are pushing to ban or limit hookah bars because of health concerns.

Hookahs, or water pipes, would be banned or limited under bills introduced in California, Connecticut and Oregon, The New York Times reports. Some cities in California and New York have already taken these steps, while Boston and Maine no longer exempt hookah bars from their indoor-smoking laws, the article notes.

Hookah bars feature water pipes that are used to smoke a blend of tobacco, molasses and fruit called shisha. Researchers say that contrary to the belief of many hookah smokers, the water in the pipe does not filter all the harmful chemicals in tobacco smoke. The World Health Organization (WHO) noted in a report that the smoke inhaled in a typical one-hour hookah session can equal 100 cigarettes or more. The WHO report also stated that even after it has been passed through water, the tobacco smoke in a hookah pipe contains high levels of cancer-causing chemicals.

A recent study of North Carolina college students found that 40.3 percent reported ever having smoked tobacco from a hookah, compared with 46.6 percent who reported ever having smoked a cigarette.