Comparison of radiological changes in humans and beagles with skeletal deposits of radium.
At the Laboratory for Energy-related Health Research at the University of California, Davis, semimonthly injections of 226Ra were given to a group of beagle dogs, and periodic skeletal radiography followed, as well as histological studies of the bones. At the Center for Human Radiobiology (Argonne National Laboratory, Massachusetts Institute of Technology, New Jersey Radium Research Project) measurements were made of radium body content in 2259 occupationally or iatrogenically exposed persons. Of these, 1768 had skeletal radiography (one or more times). In humans, the radiographic changes were, in decreasing order of frequency, osteolytic cortical and cancellous bone destruction, bone sclerosis, pathological fracture, and avascular necrosis of bone. In beagles, osteolytic destruction and pathological fractures were common, avascular necrosis was not observed, but there was frequently cortical thickening and new-bone formation in cancellous bone. In both population groups, there was a high incidence of bone sarcoma. In the beagles, one high-dosage group numbering 38 dogs had 49 malignant bone tumors. Among the 2259 measured persons, there were 60 who had bone sarcoma, and 29 who had cancer of the mastoids or paranasal sinuses. No significant skeletal effects have been diagnosed radiologically in persons with systemic intakes of 226Ra or 228Ra below about 10 mu Ci or with skeletal doses below about 100 rad. In humans, the lowest skeletal dose at which a bone sarcoma has been diagnosed is 890 rad, and the lowest intake associated with a bone sarcoma is 96 mu Ci 226Ra or about 1.7 mu Ci per kg body weight.