Carbon monoxide uptake in cigarette smoking.

A study was carried out to determine whether smoking (1) regular, (2) low-nicotine-low-tar, or (3) nontobacco (lettuce leaf) cigarettes has a differential effect upon an individual’s carboxyhemoglobin (COHb) level. Each subject in the study population participated twice in five “smoking treatments” in which they smoked various tobacco and nontobacco cigarettes. Expired-air carbon monoxide (CO) samples were taken four times daily to estimate COHb concentrations. Results indicate that different cigarette preparations do not result in significant variation in a subject’s COHb level. There was a significant difference, however, in COHb between individual smokers. It may be that differences in inhalation practices or factors such as pulmonary function are of some importance in determining whether an individual achieves low, moderate, or high COHb levels while smoking.