Mammalian biology group

Opposition to accelerated nuclear power development is based largely on concern that the potential health hazards of transuranium elements are excessive and that current health protection standards are inadequate. Because no cancer ascribable to plutonium has occurred to date in occupationally exposed populations, an attempt to estimate carcinogenicity in experimental animals has been initiated. Plutonium-bearing ceramic microspheres have been administered by both intravenous and endotracheal routes, and polonium-210 sols have been insufflated for the purpose of comparing localized ''hot particles'' and diffuse irradiation on lifetime tumor incidence. Additional studies involve life shortening, measurement of delayed radiation injury, and histopathological and chromosomal damage as criteria for assessing the hazards of various conditions of radiation exposure. The retention patterns for specific radionuclides in several species are now being extended to include other potential environmental toxic agents