Radium in Human Bone: The Dose in Microscopic Volumes of Bone

Abstract

The terminal Rn/sup 226/ distributions found in bone samples from individuals who carried radium 20 years or raore have been measured. These distributions have been expressed as terminal dose rates, in units of rads per day. The activity in the diffuse distribution of radium has been found to be relatively uniform in cortical bone. The average magnitude of this activity is about one-half of the hypothetical uniform distribution, i.e., the body burden divided by the bone weight. The specific activities found in the hotspots are, on the average, ninety times as great as that in the diffuse distribution, or thus about forty-five times as great as a hypothetical uniform distribution. From a calculated blood curve, constructed to describe the disappearance of Ra/ sup 226/ from the blood of those patients who received equal weekly injections of RaCl/sub 2/, we can predict the specific activity at which the hotspots were formed. Since the terminal activities are less than onetenth this value, we assume that a long-term exchange process may have removed nine-tenths of the original activity over a 26-year period. (auth)