Hookah use: A Science Update on a widely read subject

A DrPHealth posting from April 20 2012  on hookah hazards has recently come under significant activity. Now the second most visited posting and likely to move into the most viewed within a month.   The question of course being why?   Seems a moderate about of internationally directed traffic to the site.

For those following the issue, some recent publications are worth reviewing on health effects of hookah smoking.  CDC December 2013 with a key emphasis that while smoking sessions are less frequent, that their length results in inhalation levels comparable to more than a pack of cigarettes, and the actual amount of smoke inhaled may closer to a hundred or more cigarettes. However much of the CDC statement is based on equivalency risk for hookah smoking compared to cigarettes and not separately derived.  CDC delved deeper in policy options their Preventing Chronic disease 2012 publication again not based on specifically directed science. 

The science remains sketchy, though not reassuring.   A 2012 article in AJPH measured PM2.5 levels in hookah lounges with average readings for just being in the lounge.  For nine of ten lounges the ranges were 67 to 220 ug/m3, all unhealthy and comparable to significant fire smoke event situations.  One lounge averaged over 700, suggesting that even among hookah lounges there are characteristics that could mitigate or exacerbate potential health impacts. 

One case control study from Pakistan suggested lung cancer risk was six times greater than non-smokers, while smokers had a four times increase over non-smokers.  An early Pakistan study on increases in Carcinogenic Embryonic Antigen (CEA) has received considerable critique for biases. 

There is a minor research line on hypoxia impacts, carbon monoxide levels and related evidence of polycythemia among users.  There is considerable research focuses on behavioural sciences such as population use and decision processes, some looks at ecological relationships such as esophageal cancers over geographic regions. 

Conversely the number of papers on synthesis of knowledge, on policy implementation and on the purported health hazards of hookah appear to exceed primary research on the topic.

Hence, while policy has moved appropriately forward and science remains suggestive that the risks of hookah use are comparable or worse than cigarette smoking, our knowledge base on measured risks remains sketchy.   Certainly there is little published anywhere suggestive that hookah is a safer alternative than smoking.  

Hookah use is often precluded through appropriate smoking control regulation and the existing evidence continues to support its preclusion.