Comparison of Hookah and Cigarette Smoking
Condition: Smoking
Study type: Interventional
Phase: Phase 1

Summary: 
      The aim of this study is to compare exposure to tobacco smoke toxins in individuals who smoke
      both cigarettes and Hookah pipes. Sixteen subjects will be hospitalized on the research ward
      for two visits of 4 days each. At one visit they will smoke their usual cigarettes in
      approximately normal frequency, and at the other visit they will smoke Hookah at least twice
      per day. The order of the visits will be randomized. On the fourth day of each visit (when
      nicotine, carbon monoxide (CO), and some carcinogen levels will be in a steady state
      condition), circadian blood and urine and expired air samples will be collected.
    

Detailed description: 
      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, Tobacco-Related Disease Research Program (TRDRP) invited
      research grant applications on all aspects of hookah smoke.
    

Intervention name(s): Cigarette; Hookah
Intervention type(s): Drug; Drug
Other intervention name(s): Participant will smoke their usual brand of cigarette; participant will smoke hookah
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Keywords: hookah; cigarette; smoking