Comparative deterministic effects of inhaled, insoluble alpha- and beta-particle-emitting radionuclides in dogs

This report compares the deterministic effects from an alpha-particle-emitt ing radionuclide, (PUO2)-P-239, and a beta-particle emitter, Ce-144 in fuse d aluminosilicate particles (FAP). The studies were conducted in beagle dog s of both genders exposed by inhalation to aerosols of the radionuclides. T he initial lung burdens of (PU)-P-239 and Ce-144 were determined by whole-b ody counting of the Yb-169 added to the plutonium aerosol during its prepar ation or the Ce-144 and its progeny Pr-144. In addition, organ retention da ta were obtained from parallel serial sacrifice studies with the same aeros ols. After exposure, the dogs were observed for health effects over their l ifetime. The deterministic effects observed for both of these relatively in soluble aerosols were lymphopenia, fibrosis, atrophy of the lung-associated lymph nodes, and-radiation pneumonitis. Due to the longer half-life of plu tonium, the lymphopenia was more prolonged and the clinical course of the r adiation pneumonitis more chronic than that resulting from cerium. The grea ter tissue penetration of the beta-particle emissions from the cerium resul ted in more uniform dose distribution over the lung and the atria of the he art than from the alpha-particle emissions from plutonium. (C) 1999 by Radi ation Research Society.