Hookah pipes – a new generation of smoking hazard

This posting receives significant ongoing visits and is one of the most visited blog postings for this site.   For those interested in the hookah topic, please see the update on science of Hookah posted DrPHealth February 17 2014     

The use of waterpipes stems from the 16^th century somewhere in the Indo-Persian region.  It is a product of the introduction of tobacco from the New World to European and subsequently Asian cultures.  Ironically, the intent in the use of waterpipe was to purify tobacco smoke by passing it through water before inhalation to reduce already suspect health impacts of the time.  The dating to only the 16^th century raises interesting questions on what historic value do certain practices need in order to be considered of “cultural significance”. 

The cooler and moister smoke makes for deeper inhalations rather than the more traditional “puff” of nicotine-seeking behaviour associated with cigarettes.  The process of heating tobacco also results in lower temperatures of the smoke, suggesting the potential for a different chemical mix. That the tobacco is heated by charcoal or other burning substances rather than directly burning the tobacco adds more chemicals to the mix.   Rather than the typical 7 minute cigarette, Hookah sessions tend to run 40-60 minutes.  During that time users will supposedly inhale anywhere from 100-200 times the smoke volume of a cigarette.   Granted, the weekly consumption totals will be highly varied as Hookah sessions are much less frequent. To complicate the analysis further, more recently there has been the shift from using tobacco to tobacco-free alternatives raising questions on different substances, their chemical composition when burnt and their potential health risks.

Newer technologies, newer forms of recreation, and once again public health authorities are needing to race to determine if the new form is safer or more harmful than the standard cigarette.   Similar debates have occurred with smokeless tobacco, pipes and cigars.  The WHO took an initial step in 2005 with a preliminary advisory report WHO and water pipes  and suggested that waterpipe smoking of tobacco is a serious potential health hazard. 

Initial work has focused mostly on the toxicology.  Simply put, there is nothing to suggest that Hookah tobacco smoke is any less toxic than cigarette smoke – in fact evidence leans to a greater complexity of potential health risks.  Some comparisons between tobacco and tobacco-free products suggest that the difference is minimal although nicotine is substantively reduced.   The following table was taken from a report that is not published but compares typical water pipe sessions with tobacco and tobacco free substances with a reference single cigarette. 

Shihadeh, Does switching to a tobacco-free waterpipe product reduce toxicant intake?  (undated manuscript)

The second step in the public health analysis takes to looking at human health impacts.  For this, Akl et al undertook a systematic review in 2010 http://ije.oxfordjournals.org/content/39/3/834.long  and found for tobacco related waterpipe smoking had elevated risks for lung cancer (Odds Ratio 2.1),  respiratory illness  (2.3) and Low birth weight (2.1).  Other associations were not seen as significantly increased.  The quality of the evidence for the review was considered very low to low – suggesting much to be done in epidemiological analysis before definitive health statements can be made.

The dilemma for the public health professional becomes to what extent does definitive negative health impact have to be proven before interventions are undertaken to reduce waterpipe use and its associated disease impacts?   As the popularity of the social event of sharing the Hookah increases, especially amongst youth, the need to intervene must be balanced with sufficient evidence to be able to legally defend any protective interventions.  It is truly an emerging public health threat.