Radium ( Ra226) and Radon (${\rm Em}^{222}$) Metabolism in Dogs

The metabolism of radium in beagle dogs after a single intravenous injection was studied. Radon exhalation in dogs was compared with radon exhalation data for other species, and a theoretical method for calculating radon retention and excretion ratios is presented. The metabolism of radium and calcium-46 in dogs was compared, and considerable differences were found in renal clearance rates, plasma levels, and skeletal binding. Radium retention in beagles was found to decrease as age at injection increased. Calculations of average radiation dosage from deposited radium in beagles are compared with dosage measurements made on humans. (C.H.)