Estimating the hazards of less hazardous cigarettes. II. Study of cigarette yields of nicotine, carbon monoxide, and hydrogen cyanide in relation to levels of cotinine, carboxyhemoglobin, and thiocyanate in smokers

Abstract

Yields of chemical constituents such as tar, nicotine, CO and HCN defined by smoking machines are commonly assumed to provide a reasonable indication of the relative hazard associated with smoking a given brand of cigarette. Results suggest that this assumption should be carefully reexamined. Subjects (240), representing a wide range of smoking and brand characteristics, were recruited for an investigation of possible relations between brand yields and exposure (levels of HbCO, breath CO, plasma cotinine, plasma thiocyanate and saliva thiocyanate). Exposure was highly correlated with consumption (number of cigarettes/day) but there was no correlation between any estimate of exposure and brand yield when level of consumption was held constant. A comparison of levels of HbCO and plasma thiocyanate for 16 smokers of low-hazard and 15 smokers of high-hazard cigarette brands revealed little difference between the 2 groups, even though average cigarette yields differed as much as 2- to 3-fold. A possible explanation for the results may be that current values for average puff volume, duration and interval differed significantly from those used in programming smoking machines, particularly in the case of brands with low nicotine delivery.