Studies on the nicotine exposure of individual smokers. I. Changes in mouth-level exposure to nicotine on switching to lower nicotine cigarettes.

Twenty-four subjects smoked two brands of filter-tipped cigarettes delivering different amounts of nicotine, on the following 4-week schedule: 1. Smoking their usual brand for 1 week. 2. Smoking another brand similar in size, but delivering less nicotine, for 2 weeks. 3. Reverting to their usual brand for 1 week. The amount of nicotine entering the mouth, defined as the mouth-level exposure, was estimated from a determination of the amount of nicotine trapped in the filter of each cigarette smoked. The results indicate a substantial variation in mouth-level exposure for the subjects studied, even among smokers of cigarettes that deliver similar amounts of nicotine when smoked on a machine under standard conditions. For the majority of subjects, however, changing to a lower nicotine cigarette reduced the total daily mouth-level exposure to nicotine and, therefore, presumably the total tar intake.