PARTICLES DO NOT INCREASE VAPOR-DEPOSITION IN HUMAN AIRWAYS

Highly water-soluble vapors deposit in the upper airways of the respir atory tract because they are rapidly absorbed by the mucus lining and therefore it has been thought that the pulmonary region is not exposed to these pollutants. Yet these vapors also dissolve in the liquid-wat er portion of atmospheric particles and these particles may be vectors for depositing the pollutants in the more-sensitive pulmonary region. In this work, we simulate hear and mass transport in the lumen during inhalation to predict the deposition patterns of inhaled water-solubl e vapors both in the presence and absence of aerosol liquid water. It is found that under atmospheric conditions particles do not significan tly alter the deposition pattern of water-soluble vapors. (C) 1998 Els evier Science Ltd. All rights reserved.