Strontium-90 and radium-226 toxicity: experimental design and current status

The biologic effects of 90Sr and 226Ra in the beagle dog are being investigated to predict the possible long-term hazards to people from chronic exposure to low levels of irradiation. Animals received graded dosages of either radionuclide by several means of administration: (a) continual ingestion of 90Sr; (b) a single intravenous injection of 90Sr; or (c) a series of eight intravenous injections of 226Ra. Although administration of 90Sr and 226Ra ended at 540 days of age, the animals throughout life continued to receive chronic, low level radiation doses from these important bone-seeking radionuclides. The significance of these low doses given at low dose rates is being investigated with regard to cancer production, physiologic well-being, and shortening of life