I. Cesium-137 Metabolism in Man

Abstract

The study of the metabolism and distribution of cesium-137 is of particular interest at present because it is a biologically important fission product present in radioactive fallout. Animal experiments have shows species differences in the excretion patterns of parenterally and orally administered Cs137. For example, in rats and rabbits the primary route of excretion is via the kidney, whereas in cows and sheep most of the cesium is excreted in the feces (1-3). In sheep, 50% to 80% of orally ingested Cs137 was found to be absorbed (3). Tissue distribution studies in animals have shown that the largest concentration of cesium per gram of wet tissue is found in muscle (1-3). Previous investigations of cesium in man have been primarily concerned with the measurement of the levels of fallout-produced Cs137 in various population groups (4). Recently, with the development of total-body counters, it has also been possible to measure the biological half-life of Cs137 in man (5, 6). The results obtained with these measurements are discussed in Part II of this presentation. This report describes a study of the excretion and distribution of Cs137 man, after both oral and intravenous administration of tracer doses of this isotope. Attempts to increase the excretion rate of Cs137 by various chemical agents are also described.