There is a mistaken belief that smoking a hookah, which filters smoke through water, removes toxic components of tobacco.

This Iranian study compared the effects of hookah and cigarette smoking on lung function and respiratory symptoms and found similarities between hookah smoking and deep inhalation cigarette smoking.

The study included 57 hookah smokers, 30 deep inhalation cigarette smokers, 51 normal inhalation cigarette smokers, and 44 non-smokers.

All measures of pulmonary function in hookah smokers and deep inhalation cigarette smokers were worse than those of non-smokers, as were some measures among regular inhalation cigarette smokers.

Wheezing, tightness of the chest, and coughing were more common and more severe among hookah smokers and cigarette smokers than among non-smokers.

Hookah smoking had “profound” effects on lung function and respiratory symptoms, which were similar to the effect seen with deep inhalation cigarette smoking.