A hookah is a water pipe that is used to smoke tobacco. It has been used for centuries in the Middle East and is gaining popularity in the West. With smoking cigarettes becoming more stigmatized, smoking hookah has become more popular and is even a social activity. However, the thinking that smoking hookah is safer is incorrect.
Hookah smoke is still unhealthy. It has the same and even more contaminants and carcinogens as cigarette smoke. (tar, carbon monoxide as well as nicotine) In addition, use of charcoal at the top delivers even more carcinogens. A greater amount of smoke is inhaled because of the longer period of smoking. It can create dependence just like cigarette smoking and it also presents the same second hand smoke dangers. According to Dr. Marc Siegal: (there is) "increasing evidence about hookah use being linked to lung and oral cancers, heart disease, and low birth weight in infants. Another risk comes in the form of infectious disease if users are sharing the same mouthpiece with others."
Take a look at these links to learn more.
http://www.cdc.gov/tobacco/data_statistics/fact_sheets/tobacco_industry/hookahs/
http://foxnewsinsider.com/2014/07/10/what-are-health-risks-hookah-smoking
http://www.washingtonpost.com/news/to-your-health/wp/2014/07/10/1-in-5-teens-smoke-hookah-half-think-its-healthful/