AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Modeling Deposition of Cigarette Puff Mixture in Human Lungs
BAHMAN ASGHARIAN, Owen Price, Caner Yurteri, John McAughey, Applied Research Associates, Inc.
Abstract Number: 25 Working Group: Health Related Aerosols
Abstract Biological response from smoking is directly related to the dose of inhaled cigarette puff. Thus, to study the health impact of smoking, the inhalation of cigarette puff must be studied to determine the site and amount of deposition on lung airway surfaces. Deposition and uptake of components of cigarette smoke in the lung, which may be present in both droplet and vapor forms, are directly related to their thermodynamic states in the smoked air. Uptake of a vapor component depends on partition coefficient while droplet deposition depends on physical size. The smoke mixture undergoes a continuous phase change, which affects both vapor uptake and droplet deposition. To study the fate of inhaled smoke puff, a unified model of vapor uptake and droplet deposition for cigarette smoke was developed in which a two-way coupling was assumed between the vapor and droplet phases. Droplet evaporation reduced its size while increasing the concentration of its components in the vapor phase of the smoke. In addition, droplets underwent coagulation and hygroscopic growth while their movement and deposition were affected by their colligative behavior (particle-particle interaction or cloud effect). The cigarette puff was assumed to be made up of nicotine, water, soluble and insoluble components of tar. The presence of vapor nicotine reduced the evaporation rate compared with the case of no vapor nicotine present in the air. However, cigarette droplets were void of nicotine when reaching the alveolar region. Hence, lung dose of nicotine was mainly due to vapor uptake. Model predictions were in agreement with reported measurements. This study was funded by British American Tobacco Investments Ltd.