Intrapulmonary deposition and retention modeling of chrysotile asbestos fibers in rats.
Yu-CP; Asgharian-B; Pinkerton-KE
J Aerosol Sci 1991 Jan; 22(6):757-763
A theoretical model was presented to simulate the deposition and clearance processes of chrysotile (12001295) asbestos fibers in an asymmetric lung in order to explain the observed nonuniformity. The lung burdens of fibers of different size ranges in each alveolar region of the rat lung were calculated for an exposure condition of 7 hours a day, 5 days a week for a 12 month period. Regions with fewer airway generations in their path had a higher value of fiber retention and a longer mean length. The smaller fiber accumulation in the region with high airway generation number was attributed to the greater loss by deposition along the airway path. The authors note that because deposition of fibers occurs mostly at airway bifurcations, an airway path ending at a higher airway generation number would have a larger deposition loss. Since long fibers have a higher deposition efficiency at the bifurcation than the short ones, a smaller fraction of long fibers will reach the alveolar space. The mean fiber length in a region of higher generation number will therefore be smaller.
Tissue-distribution; Body-burden; Laboratory-animals; Lung-irritants; Alveolar-cells; Respiratory-system-disorders; In-vivo-study; Inhalation-studies; Asbestos-fibers; Airborne-fibers
Journal of Aerosol Science
University of California - Davis