Studies on the nicotine exposure of individual smokers. II. An analysis of smoking habits during a one-week period.

The smoking habits of 30 smokers, consisting of monozygotic and dizygotic twins, were investigated in order to order check whether a subgroup of these smokers exhibited a pattern which could be associated with addiction to nicotine. The results showed that smoking patterns varied in the course of a day, although no consistent pattern emerged which indicated that a significant sub-group of smokers was addicted strongly to nicotine. Moreover, on the basis of the associations of mouth level exposure obtained from a specific cigarette, and the time intervals when a cigarette was smoked before or after a specific cigarette was smoked, it appears that the sub-groups of smokers which self-titrate nicotine to any appreciable extent is probably small.