Effect of cigar smoking on carboxyhaemoglobin and plasma nicotine concentrations in primary pipe and cigar smokers and ex-cigarette smokers.

Five ex-cigarette smokers and five primary pipe and cigar smokers each smoked a large cigar. Carboxyhaemoglobin (COHb) and plasma nicotine levels were measured. In the ex-cigarette smokers mean COHb rose from 2.9% to 9.6% and plasma nicotine from 79.0 nmol/l to 281 nmol/l (12.8-45.6 ng/ml). This response was similar to that of cigarette smokers smoking cigarettes, which indicated that the subjects had inhaled and absorbed significant amounts of nicotine. In the primary pipe and cigar smokers the mean COHb rose from 0.8% to 1.0% and the plasma nicotine from 21 nmol/l to 32 nmol/l (3.4-5.2 ng/ml), indicating neither significant inhalation nor significant nicotine absorption.Since ex-cigarette smokers do not seem to lose their habit of inhaling when they change to cigars, measures aimed at persuading smokers to switch to cigars will have little effect on their health. Pipe and cigar smokers who have never smoked cigarettes do not inhale, which probably accounts for their reduced incidence of coronary heart disease and lung cancer. But they also appear not to absorb nicotine, which suggests that nicotine is absorbed largely from the lung and that the buccal mucosa is unimportant. It also raises the interesting question of why primary pipe and cigar smokers do smoke.