Carbon monoxide exposure from commercial brand cigarettes under controlled smoking conditions

Carbon monoxide (CO) exposure from ultralow-, low- and high-CO delivery commercial cigarettes was examined under controlled smoking conditions. Seven chronic smokers of mid- to high-CO delivery commercial cigarettes served in the experiment. CO level increases of 2.10, 5.76 and 7.38 ppm were obtained from ultralow-yield (1.6 mg CO delivery), low-yield (5.9 mg CO delivery) and high-yield (14.3 mg CO delivery) cigarettes, respectively. Subjects achieved significantly higher increases in CO levels from both low- and high-yield cigarettes than from ultralow-yield cigarettes, but increased levels of CO from low- and high-yield cigarettes were not different from each other. The data suggest that degree of CO absorption by the lungs during a short period of time may limit increases in CO levels obtained from high-yield cigarettes.