Figure 1 – Socially accepted: group of young adults smoking hookah at a festival 
Almost 50% of US-undergraduates report use of hookah as well as almost 60% of British adolescents using cigarettes. Every summer, I see dozens of people, most of whom are young adults, smoking shisha in public places, especially in bars or outside. Is this surprising? World tobacco day offers a great opportunity to check the most common stereotypes. But before we discuss the interesting part concerning the effects of shisha smoking, let’s quickly dive into some basic overview.
What’s the history?
It’s not exactly clear when water pipes emerged first, but it’s safe to say everything started centuries ago in Africa and Asia, where indigenous people invented a supposedly less harmful way of smoking. Today, shishas commonly are associated with India and most of the expressions surrounding it stemming from Hindi.
What does Hookah or shisha smoking mean?
Generally spoken, it translates best to water pipe tobacco smoking, where the syrupy tobacco mix, containing the tobacco itself as well as some extras, is called Mu’assel. Often special flavours such as watermelon, strawberry or even caramel are added as well. 
The tobacco itself is placed in the headpiece of the Hookah and topped with charcoal, causing it to burn. The inhaling smoker creates a vacuum that induces a hot air stream passing through the coal and the tobacco, moving via the body of the hookah into the bowl. After bubbling through the water-filled bowl, the smoke reaches the hose with a mouthpiece and is inhaled. To keep this system running, the coal needs to be refilled from time to time and the smokers pass around the hose.
What are the health effects?
To answer this question, it’s essential to keep in mind that the substance you are smoking is still tobacco and that the water does not exactly work like a filter. The smoke you inhale contains numerous toxicants such as hazardous gases (carbon monoxide) or cancer-causing chemicals, but also nicotine, the extremely addictive drug known from cigarettes. It is true that the water significantly reduces the nicotine dose per inhalation, but keep in mind that this is even more dangerous considering overdoses. Compared to cigarettes, the total dose per session is a lot greater choosing the Hookah as the volume per puff is significantly higher. On average, it takes five to seven minutes to smoke a cigarette as opposed to the social event of smoking a Hookah for one hour or even longer. In other words: The amount of smoke and hence all its (toxic and addictive) components inhaled during one shisha session is pretty much the same as smoking roughly 100 cigarettes.
You can probably imagine that the specific health risks are very similar to other kinds of tobacco use, including respiratory issues, heart diseases and many types of cancer.
What is so problematic?
Reviewing statistics, smoking shisha is an essential social event in many cultures, seen as hardly dangerous and therefore practised in family gatherings including children and among friends. Sharing the same mouthpiece within a group adds the risks of spreading diseases such as hepatitis or tuberculosis. Also, Hookahs seem to be quite attractive to young people due to a missing stigma and special tobacco flavours that are often sweet or fruity.
What can I personally do?
First, remember an easy take-home message: Water pipe smoking definitely is not a safe alternative to cigarettes! Depending on the coal, there are additional and unique risks concerning the smoke containing heavy metals and toxic chemicals. Tools reducing these risks have not been proven effective yet.  In order to protect yourself, also as a second-hand smoker, it is essential to inform people around you whenever this topic comes up. The concept is as simple as it sounds: Wiping out the current misconceptions is the best method of prevention!
 ”NW Folklife 2009 – Hookah smokers.jpg”, Wikimedia, May 2009https://commons.wikimedia.org/wiki/File:NW_Folklife_2009_-_Hookah_smokers.jpg
 “A comprehensive examination of hookah smoking in college students: Use patterns and contexts, social norms and attitudes, harm perception, psychological correlates and co-occurring substance use”, ScienceDirect, July 2013
 “Examining Hookah Smoking Among a Cohort of Adolescent Ever Smokers”, Oxford Academic, September 2011
 “Hookah”, Wikipedia, May 2020 https://en.wikipedia.org/wiki/Hookah
 “Mu’assel”, Wikipedia, April 2020 https://en.wikipedia.org/wiki/Mu%E2%80%98assel
 “Waterpipe Tobacco Smoking: Health Effects, Research Needs and Recommended Actions by Regulators”, WHO TobReg, June 2005 https://www.who.int/tobacco/global_interaction/tobreg/Waterpipe%20recommendation_Final.pdf
 “Hookahs”, Centers for Disease Control and Prevention, January 2020 https://www.cdc.gov/tobacco/data_statistics/fact_sheets/tobacco_industry/hookahs/index.htm