Toxicity of inhaled 91YCl3 in Beagle dogs. XVI

The metabolism, dosimetry and biological effects of inhaled 91YCl3 in Beagle dogs are being studied. Forty-two dogs with initial 90Y body burdens from 14 to 1300 μCi per kilogram body weight and 12 control dogs are being maintained for lifetime observation. Four additional dogs with a mean initial body burden of 180 μCi 91Y per kilogram body weight were placed in a sacrifice study. Forty-four of the exposed dogs and all 12 of the control dogs have died. Dogs with the highest initial body burdens died with bone marrow damage and pancytopenia. Three dogs died with nasal cavity carcinomas, three dogs died with pulmonary carcinomas and one dog died with hepatic hemangiosarcoma; these cancers all appeared to be related to radiation injury. Control dogs died of miscellaneous neoplastic and chronic diseases. Observations are continuing on the two surviving exposed dogs