THE DEPOSITION OF AEROSOLS IN THE RESPIRATORY TRACT: II. DEPOSITION IN CIGARETTE SMOKING

Abstract

A computer program was developed which calculates the deposition of cigarette smoke particles in the respiratory tract of the smoker. The basic equations used to describe the particle deposition and the mixing of air in the respiratory tract have been described in a previous publication by the author on the deposition of aerosol particles during normal breathing. However, an improved model of the respiratory tract, similar to a model suggested by Weibel, was employed. Comparison of the computer results with experiments was difficult, because of the absence of complete data in the literature. However, when estimates were made regarding the true experimental conditions under which certain results on smoke retention were obtained, a partial correlation was made possible by assuming a much larger mean particle size than is known to exist in raw smoke. The increase in mean particle size was tentatively ascribed to water absorption in the respiratory tract. Even with this assumption, the correlation was extremely poor at very low smoke inhalation volumes.The computer program analysis indicated that it should be possible to substantially reduce smoke deposition, without reducing smoke inhalation, by puffing on the cigarette at some point in the breathing cycle other than at the end of expiration, as is customary. This method of smoking was found to be as pleasurable as the normal method by most of the smokers who have used it.