Relative Biological Effectiveness of Radium and Other Alpha Emitters in CF No. 1 Female Mice

Abstract

Plutonium 239, polonium 210, uranium 233, and thorium 228 are 20 times more efficient than radium 226 in killing 50% of a population in 20-100 days. The relative biological effectiveness (RBE) varies with the criterion of effect and with the degree of the response being measured. The best present estimate of the RBE at near-tolerance levels, based on reduction of life expectancy and induction of malignant bone tumors, is 7 (Pu239): 3 (Po210): 2 (U232): 1 (U233): 1 (Ra226).