Hematopoietic tumors in beagles with body burdens of bone-seeking radionuclides

The cumulative tumor rate for hematopoietic neoplasms in beagles with long-term body burdens of 90Sr, 224Ra, 226Ra, 228Ra, 228Th, 239Pu, 241Am, /sup 243/244/Cm, 249Cf, 252Cf or 253E was similar to that of the non-radioactive control dogs. In both instances, the earliest tumor appeared at 5 to 6 years of age and the incidence rate began to increase appreciably at approximately 10 years of age. Hematopoietic neoplasia was principally a disease of the older animals, and a definite relationship to the radionuclide burden was not apparent when all of the neoplasms were combined under the general category of hemic tumors. However, a difference between the control and irradiated groups was noted in the spectrum of tumor types. All of the myeloid and mast cell tumors occurred in the irradiated dogs