RESUMEN
We studied the carbon monoxide [CO] fractions in hookah and cigarette smoke, using a carbon monoxide micro smokeriyzer [model EC50, BEDFONT, U.K.]. Mean carbon monoxide fractions [% by volume] of hookah smoke, using domestic charcoal were 0.38 +/- 0.07 [large hookah; unfiltered]; 1.40 +/- 0.43 [small hookah; unfiltered]; 0.34 +/- 0.06 [large hookah; filtered]; 1.36 +/- 0.35 [small hookah; filtered] and 0.41 +/- 0.08 [cigarette smoke]. The highest fractions were obtained with small size hookah and increase in size of hookah [i.e., volume of air in water base, fire bowl volume, pipe length, etc.] reduced the CO fraction significantly [P<0.001]. The fractions of cigarette lie between large and small hookah. The fractions vary slightly with different varieties of tobacco, e.g., CO fractions with Dera wala tobacco are significantly low [P<0.05]. Use of commercial charcoal gives significant rise in CO fractions [P<0,001] Comparison of filtered and unfiltered smoke shows no significant difference in values. We conclude that the CO hazard is as high with hookah smoking as with cigarette smoking