Comparison of Hookah and Cigarette Smoking

Water pipes have been used to smoke various substances for at least four centuries,
particularly in certain Asian countries, the Middle East, and Northern Africa. It is
estimated that about 100 million people worldwide smoke tobacco in water pipes, which are
also known as hookahs (Indian subcontinent and Africa), shisha, borry, goza (Egypt, Saudi
Arabia), narghile, argilhe (Jordan, Lebanon, Syria, and Israel), shui yan dai (China), or
hubble-bubble.

Water pipes consist of a head (to hold tobacco) which is connected to a body, which in turn
is connected to a bowl containing water. A tobacco preparation is placed in the head, and
burning charcoal is placed on top of the tobacco, often separated by perforated aluminum
foil. The smoker inhales through the mouthpiece, which draws air over the burning charcoal
and through the tobacco, creating an aerosol consisting of volatilized and pyrolized tobacco
components. The smoke passes through the water in the bowl, cooling the smoke, before being
carried through the hose to the smoker.

Hookah tobacco is different from ordinary tobacco in that it is a moist paste-like
preparation made from about 30% crude, cut tobacco that is fermented with honey, molasses,
and pulp of different fruits to add flavor. Consequently, differences in composition of the
products smoked and different temperatures involved in the smoking process result in
substantial difference in the composition of hookah smoke compared to cigarette smoke.
Hookah smoke is produced at about 450° C compared to about 900° C for cigarettes. In
addition, hookah smoke contains charcoal combustion products, which includes substantial
amounts of carbon monoxide (3).

In one study, Shihadeh and Saleh found that hookah tobacco produced substantially more tar
(100-fold), nicotine (4-fold), carbon monoxide (11-fold), and polycyclic aromatic
hydrocarbons (PAHs, 2 to 5-fold) than did comparable amounts of cigarette tobacco. Shafagoj
et al compared expired CO and plasma nicotine in cigarette and hookah smokers, and found
that the hookah smokers had about 2-fold higher carbon monoxide levels and about 3-fold
higher nicotine levels than cigarette smokers. The high delivery of nicotine is unexpected
in light of its high water solubility.

Recently, smoking tobacco in water pipes has gained popularity in the US, particularly in
areas with sizable Arab-American populations, and also among young non-Arab-Americanpeople,
with a number of hookah bars being located near college campuses. A typical session at a
hookah bar involves smoking for 45-60 minutes, often with a group of friends (1). In
addition, hookahs, hookah tobacco, and accessories are advertised over the Internet. Most
users of hookah tobacco believe that it is not addictive, and less harmful than cigarette
smoking.

In light of published studies indicating high nicotine and carbon monoxide exposures in
hookah smokers, the lack of data on exposure to other toxic substances, and global increases
in the prevalence of hookah tobacco use, it is apparent that further research is needed. In
the August, 2005 newsletter, TRDRP invited research grant applications on all aspects of
hookah smoke.