Relationship Between Ingestion, Excretion and Accumulation of Fallout Cesium-137 in Man on A Long-term Scale

Abstract

Investigations were made to follow the ingestion, excretion and accumulation of fallout 137Cs in five volunteers on a long-term scale, and, at the same time, using the data so obtained to determine the biological half life of Cs as well as the fraction of this nuclide in urine of that in total excreta. The dietary intake, daily excretion and body burden of 137Cs increased since 1962 to the maxima in the middle of 1964, but thereafter the levels began to decrease. The relationship between the body burden and the total excretion indicated biological half lives of from 57 to 138 days. The mean value was 80 days. It was noticed that the biological half lives varied somewhat between and for the same individuals. Urinary excretion divided by total excreta ranged from 0.74 to 0.91, and the mean value was 0.86 in the subjects. The corresponding values for K are also studied and they are compared with those for 137Cs.