Modeling of deposition and clearance of inhaled Ni compounds in the human lung

Hsieh, TH; Yu, CP; Oberdörster, G

HERO ID

758251

Reference Type

Journal Article

Year

1999

Language

English

PMID

10464043

HERO ID 758251
In Press No
Year 1999
Title Modeling of deposition and clearance of inhaled Ni compounds in the human lung
Authors Hsieh, TH; Yu, CP; Oberdörster, G
Journal Regulatory Toxicology and Pharmacology
Volume 30
Issue 1
Page Numbers 18-28
Abstract By extrapolation from the rat study, a mathematical model of deposition, clearance, and retention kinetics for inhaled Ni compounds (high-temperature (green) NiO, Ni(3)S(2), and NiSO(4). 6H(2)O) in the alveolar region of the human lung has been developed. For human deposition, an updated version of an earlier model (C. P. Yu and C. K. Diu, 1982, Am. Ind. Hyg. Assoc. J.) was used in this study. Because of the profound differences in physiological and ventilation conditions between humans and rats, humans were found to have a higher alveolar deposition fraction than rats when exposed to the same Ni compounds. However, when normalized to the lung weight, the deposition rate per gram of lung in humans is much smaller than in rats. In the development of a clearance model, a single-compartment model in the lung was used and a general assumption was made that the clearance of the insoluble and moderately soluble nickel compounds (high-temperature (green) NiO and Ni(3)S(2), respectively) depends highly on the volume of retained particles in the lungs. As for the highly soluble nickel compound (NiSO(4). 6H(2)O), the clearance rate coefficient was assumed to depend on the retained particle mass and total alveolar surface. These clearance rate coefficients were extrapolated from the rat data. The retention half-times for high temperature (green) NiO and Ni(3)S(2) particles in humans were found to be much longer than in rats, whereas the retention half-time for NiSO(4). 6H(2)O particles was about the same for both species. The lung burden results in humans for various exposure conditions are predicted and the equivalent exposure concentrations for humans which lead to the same lung burdens found in rats were calculated.
Doi 10.1006/rtph.1999.1313
Pmid 10464043
Wosid WOS:000082772100003
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English