[The waterpipe (shisha) - indoor air quality, human biomonitoring, and health effects]

Waterpipe (WP) smoking, also known as shisha or hookah smoking, is growing in western countries as an alternative to cigarette smoking, especially in younger age groups. A majority of smokers mistakenly believe that shisha smoking is a social entertainment practice that leads to more social behavior and relaxation and that this type of smoking is safe or less harmful and less addictive than cigarette smoking.In reality, WP smokers are exposed to hundreds of toxic substances that include well-known carcinogens. High exposures to carbon monoxide and nicotine are major health threats. There is growing evidence that WP smoke causes adverse effects on the pulmonary and cardiovascular systems and there are indications that WP smoke is associated with cancer. Persons exposed to secondhand WP smoke are also at risk.More research on the health effects of WP is urgently needed and more preventive measures for public health protection. Moreover, public WP facilities should be implemented under specific nonsmoker protection laws and consequently controlled.This review summarizes recent data on exposure to WP smoking in indoor environments, the results of biomonitoring data, and the known health effects based on currently available toxicological or epidemiological studies.