There is a strong association between water-pipe (shisha) smoking and cancers of the head and neck, oesophagus and lungs, it has been revealed in a comprehensive study by researchers at Weill Cornell Medicine-Qatar (WCM-Q).

The study, entitled ‘Cancer risk in water-pipe smokers: a meta-analysis’ has now been published in the International Journal of Public Health, WCM-Q announced on Monday.
A team of researchers led by WCM-Q’s Dr Ravinder Mamtani and Dr Sohaila Cheema, used a sophisticated meta-analysis technique to review 28 published scientific studies and examined the relationship between water-pipe smoking and various forms of cancer, including cancer of the head and neck, oesophagus, stomach, lung and bladder.
While the risks of smoking cigarettes are well known, the cancer risk associated with smoking from a water-pipe - also known as hookah and ‘hubble bubble’ - remain poorly understood.
Dr Mamtani, associate dean for Global and Public Health at WCM-Q, said the need for such a study had become urgent in recent years owing to the surge in popularity of shisha, especially among young people and women.
“There are many studies examining the risks of cigarette smoking but we must understand that smoking from a water-pipe is significantly different because the smoker generally inhales far more smoke, smokes for longer, and there are different concentrations of toxins in water-pipe smoke than in cigarette smoke.
“Further, there is a very dangerous wrong perception that water-pipe smoking is safe because the water somehow filters out the dangerous toxins in the smoke. The water only cools the smoke and does not filter out the toxins.”
Dr Cheema, director of Global and Public Health at WCM-Q, pointed out that water-pipe smoking is a very social act and in the Middle East it is more socially acceptable for women than smoking cigarettes.
“This means that patterns of use are quite different from cigarette smoking so it is vital that we study water-pipe use separately to understand the risks more clearly.”
Data from a 2014 World Health Organisation (WHO) study shows that tobacco kills up to half its users, amounting to nearly six million people each year. More than 600,000 deaths per year are the result of non-smokers being exposed to second-hand smoke. The Qatar WHO Step Survey of 2012 found that 29.1% of men in Qatar smoke, and 0.6% of women.
Unpublished WCM-Q data indicates that among adolescents in Qatar aged 15-18 years, 13% reported they had tried cigarettes and 22% that they had tried water-pipe. Among college students in Qatar, 27% said they were regular or social cigarette smokers, and 32% regular or social water-pipe smokers.
A shisha smoking session can expose the user to up to 50 litres of smoke over a 45-minute use period, compared to around one litre of smoke that is consumed by someone smoking a cigarette over about five minutes.
Shisha smokers are exposed to tar, addictive nicotine, carbon monoxide, and other harmful substances at similar levels and sometimes greater levels than cigarette smokers.
According to Dr Cheema added, WCM-Q’s analysis of the existing studies points to a clear association between water-pipe smoking and several forms of cancer and people need to be aware of this so that they can make informed choices about whether they smoke or not.
“We also determined that the number of high-quality studies into the effects of water-pipe smoking is very low, so there is a great need for more investigation in this area, especially as shisha is so popular nowadays.”
Dr. Mamtani observed that governments around the world have taken steps to reduce cigarette smoking in their populations through measures such as public health campaigns, tax policy, creating smoke-free areas and passing laws about what can be displayed on packaging.
“Until now, water-pipe smoking has managed to escape many of these measures. It is time for more studies about water-pipe smoking, more public awareness of the risks and we can also explore the opportunities for public policy on this issue to protect public health.”
Other contributing authors to the study are Dr Javaid Sheikh (dean, WCM-Q), Dr Ahmad al-Mulla (Smoking Cessation Programme, Hamad Medical Corporation), Dr Albert Lowenfels (Department of Surgery, New York Medical College), and Dr Patrick Maisonneauve (Division of Epidemiology and Biostatistics, European Institute of Oncology).