An interspecies comparison of the lung clearance of inhaled monodisperse cobalt oxide particles- Part 1: objectives and summary of results
An interspecies comparison of the lung clearance of a well-defined, moderately soluble material was conducted to aid in the development of models used to relate inhalation of radioactive particles to organ doses and bioassay measurements, and in particular to aid in the extrapolation of animal data to man. Lung retention and excretion of 57Co were followed for at least six months after inhalation of monodisperse 0.8 and 1.7 micron diameter cobalt oxide particles by human volunteers, baboons, dogs, guinea-pigs, rats (three strains) and hamsters, and of the 0.8micron particles by mice. At six months after inhalation of the 0.8micron particles, lung retention ranged from 1% of the initial lung deposit (ILD) in HMT and Sprague-Dawley rats to 45% ILD in man; and for the 1.7micron particles from 8% ILD in HMT rats to 56% in man. Supplementary experiments were conducted to determine 57Co excretion patterns following injection of Co(NO(3))(2) into the blood and following ingestion of cobalt oxide particles, in order to calculate lung clearance rates due to translocation of dissociated 57Co to the blood, S(t), and due to particle transport to the GI tract, M(t). Initially, S(t) for 0.8micron particles ranged from 0.4% of the contemporary lung content/day in humans and baboons to 1.6%/day in HMT rats. Initial values for 1.7micron particles were lower in all species, and ranged from 0.2% in baboons to 0.6%/day in HMT rats. Estimated values of M(t) were consistent with the assumption that M(t) is similar for different materials in the same species.
Bibliographic Reference: Article: J. Aerosol Sci., Vol. 20 (1989) No. 2, pp. 169-188
Record Number: 198911017 / Last updated on: 1994-12-01
Original language: en
Available languages: en