Retention modeling of diesel exhaust particles in rats and humans

Journal Article · Wed May 01 00:00:00 EDT 1991 · Research Report Health Effects Institue; (United States)

DOI:https://doi.org/10.1089/jam.1991.4.79· OSTI ID:6261770

Yu, C P; Yoon, K J ^[1]

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1. Department of Aerospace and Mechanical Engineering, State University of New York, Buffalo, Amherst (United States)

The objective of this study was to predict the lung burden in rats and humans of diesel exhaust particles from automobile emissions by means of a mathematical model. The authors previously developed a model to predict the deposition of diesel exhaust particles in the lungs of these species. In this study, the clearance and retention of diesel exhaust particles deposited in the lung are examined. A diesel particle is composed of a carbonaceous core (soot) and adsorbed organics. These materials can be removed from the lung after deposition by two mechanisms: (1) mechanical clearance, provided by mucociliary transport in the ciliated airways as well as macrophage phagocytosis and migration in the nonciliated airways, and (2) clearance by dissolution. To study the clearance of diesel exhaust particles from the lung, they used a compartmental model consisting of four anatomical compartments: nasopharyngeal, tracheobronchial, alveolar, and the lung-associated lymph node compartments. They also assumed a particle model made up of material components according to the characteristics of clearance: (1) a carbonaceous core of about 80 percent of particle mass, (2) slowly cleared organics of about 10 percent of particle mass, and (3) fast-cleared organics accounting for the remaining 10 percent of particle mass. The kinetic equations of the retention model were first developed for Fischer-344 rats. The transport rates of each material component of diesel exhaust particles (soot, slowly cleared organics, and fast-cleared organics) were derived using available experimental data and several mathematical approximations. The lung burden results calculated from the model showed that although the organics were cleared at nearly constant rates, the alveolar clearance rate of diesel soot decreased with increasing lung burden. This is consistent with existing experimental observations.

• OSTI ID: 6261770
• Journal Information: Research Report Health Effects Institue; (United States), Vol. 40; ISSN 1041-5505
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DIESEL ENGINES
EXHAUST GASES
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LUNGS
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560300* - Chemicals Metabolism & Toxicology