American Association for Aerosol Research - Abstract Submission

AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA

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Modeling Mainstream Cigarette Smoke Inhalation and Deposition in the Human Lung

BAHMAN ASGHARIAN, Owen Price, Caner Yurteri, John McAughey, Applied Research Associates, Inc.

     Abstract Number: 94
     Working Group: Health Related Aerosols

Abstract
Determination of dose to the lung of inhaled mainstream cigarette smoke aids in determining vulnerable sites in the respiratory tract, which experience enhanced deposition. Components of the cigarette smoke that may be responsible for the adverse effects can also be identified; thus providing a roadmap for harm reduction of cigarette smoking. A particle deposition model specific to cigarette smoke particles was developed for in vitro oral cavities and the lung by extending existing models for environmental particles and accounting for cigarette smoke particle size growth by hygroscopicity, phase change, and coagulation. In addition, since the cigarette puff enters the respiratory tract as a dense cloud, the impact of the cloud effect on particle drag and deposition was accounted for in the deposition model. Models of particle losses in the oral cavities were developed during puff drawing and subsequent mouth hold. Cigarette smoke particles were found to grow by hygroscopicity and coagulation, but shrank as a result of evaporation of nicotine and other volatile constituents. Predicted deposition of cigarette smoke particles was smaller than measurements when treated as a collection of non-interacting individual particles. Accounting for cloud movement provided the necessary physical mechanism to explain the greater than expected, experimentally-observed particle deposition. The deposition model for cigarette smoke particles can provide the necessary input to determine the fate of inhaled cigarette smoke particles in the lung and the rest of the body for health assessment, identification and removal of harmful components of cigarette smoke particles. This study was funded by British American Tobacco.