Should intake of carbon monoxide be used as a guide to intake of other smoke constituents?

The relation between blood carboxyhaemoglobin (COHb) and plasma nicotine concentrations was studied in a group of 12 smokers smoking cigarettes of three levels of standard delivery. While the intake of carbon monoxide from a single cigarette was unrelated to the intake of nicotine, presmoking "trough" concentrations of the two substances (reflecting longer-term exposure) were highly correlated. Various other measures of nicotine exposure were at best only moderately correlated with blood nicotine concentrations. Thus trough COHb concentrations might be used to provide a reliable indication of the exposure to nicotine of individual smokers smoking the same type of cigarette, and of the relative exposure to nicotine of populations smoking cigarettes of different standard deliveries.