Metabolism of injected plutonium in two healthy men

The metabolism of plutonium has been studied following intravenous injection of 237Pu as Pu (IV) citrate into two healthy male volunteers. Measurements of the tracer in samples of blood and excreta were made by gamma-ray spectrometry, and patterns of organ uptake were investigated through serial measurements with a scintillation counter viewing the liver and selected skeletal sites. Excretion in urine and feces measured during the first 3 wk accorded closely with the patterns deduced by Durbin from the report of Langham et al. on patients injected with 239Pu. However, concentrations in blood were roughly twice those suggested by Durbin during most of the 14 d covered by our measurements. In one subject, the liver deposit increased to a plateau after about 21 d, at roughly 55% of the injection; in the other, the increase was prolonged, reaching about 70% after several months.