http://en.wikipedia.org/wiki/HookahA hookah (Hindi: हुक्का, Urdu: حقہ hukka) or shisha (Arabic: شيشة or
أركيلة), is a single or multi-stemmed (often glass-based) water pipe device for smoking; originating in India> it has gained popularity, especially in the Arab World. A hookah operates by water filtration and indirect heat. It can be used for smoking many substances, such as herbal fruits and
tobacco. Depending on locality, hookahs may be referred to by many other names. Operation The jar at the bottom of the hookah is filled with water sufficient to submerge a few centimeters of the body tube, which is sealed tightly to it. Tobacco is placed inside the bowl at the top of the hookah and a burning charcoal is placed on top of the tobacco. Some cultures cover the bowl with perforated tin foil to separate the coal and the tobacco, which minimizes inhalation of coal ash with the smoke. When one inhales via the hose, air is pulled through the coal and into the bowl. The air, hot from the charcoal, roasts, not burns, the tobacco, producing smoke. This smoke passes down through the body tube, which extends into the water in the jar. It bubbles up through the water and fills the top part of the jar, to which the hose is attached. When a smoker inhales from the hose, smoke passes into the lungs, and the change in pressure in the jar pulls more air through the charcoal, continuing the process. The hookah''s components must be sealed tightly with grommets, or air which does not flow through the coal will dilute the smoke. Today there are also numerous varieties produced in the West with more coming to market each year. Besides being sold in little packets as is rolling tobacco, hookah is also sold in cardboard boxes and plastic jars. Packaging is generally illustrated with bright floral motifs, fruit, lush gardens and romantic images of sultans or pashas. The relative proportions of tobacco, treacle, fruits and spices, on average, 30%, 50% and 20% respectively
. The substance is generally valid for two years; boxes usually indicate the production date. Health warnings about lung cancer risks and cardiovascular disease appear on these products similar to other tobacco products elsewhere in the world. Some manufacturers like Soex produce tobacco-free flavored herbal blends and market these as shisha as well. These herbal blends typically advertise themselves as having no tar and nicotine, thus a safer alternative that is still enjoyable. Other Distributors provide tobacco-based flavored blends as well as a variety of hookahs. Health benefits and risks Today''s media sometimes suggests that hookah can be a more health threatening activity than smoking cigarettes. Research suggests that a session of hookah tobacco smoking (tobacco molasses) which lasts 45 minutes delivers slightly more tar and carbon monoxide (around 5-10%) than a packet of cigarettes.This study has, however, come under criticism for using unrealistically high temperatures for the tobacco (600-650 degrees C) and using arbitrary figures for tar filtration rates. This could possibly have skewed results, as the carcinogenic and toxin levels of smoke increases dramatically with temperature (Wynder 1958). Common practice is to keep temperatures to degrees which do not "char" the hookah; that is within a temperature range of 100-150 C. (Chaouachi K: Patologie associate all''uso del narghile). The effects of these lower temperatures on tar are inconclusive, though Chaouachi indicates the tar would be less harmful. Some hookah tobaccos claim to contain 0.0% Tar, but this is misleading due to the fact that tar is created when tobacco burns. However research has indicated that the use of the hookah may reduce comparative cancer risks, though such studies are not conclusive, Rakower, Salem 1983 and 90, Gupta Dheeraj 2001, Tandon 1995, Lubin 1992, Hazelton 2001, Stirling 1979). The levels of carbon monoxide produring a hookah session varies widely depending on the type of coal used. Japanese charcoals are thought to produce lower amounts of carbon monoxide. However there is a notable difference in areas of carbon monoxide absorption, in that while cigarettes have a notable effect on the small respiratory tracts rather, shisha smoking mostly affects the major airways (Bakir 1991, Kiter). This means a lessened FEV vs FEV1/FVC ratio compared to cigarettes, which is believed to be less harmful for the airways long-term. . this new method of smoking is aimed at replacing tobacco and its health effects. Since no reported problems have arisen with the use of Herbal shisha, there has been no need for any more extensive studies. Although the studies that have been done have shown that smoking herbal shisha as apposed to tobacco will greatly reduce the health risks associated with smoking tobacco. Many articles suggest that there is simply not enough research to provide answers to determine the effects of hookah smoking. Research is under way by Fogarty International Center-funded Syrian Center for Tobacco Studies, Egyptian Smoking Prevention Research Institute, Research for International Tobacco Control-funded Tobacco Prevention and Control Research Group at the American University of Beirut, Lebanon.