Uptake of plutonium by the human liver

The hepatic uptake of Pu-237 in 12 healthy subjects who received it intravenously as Pu(IV) citrate is reported. The results were derived from the response of a scintillation counter viewing the right lateral surfaces of the lower thorax; calibration for individual subjects was performed with Pu-237-loaded phantoms based on anatomical data from magnetic resonance imaging. The highest levels (mean 73 +/- 12 (sd) % of injection) were reached variously after 7-230 days, with no conclusive evidence of a subsequent reduction: half of the accumulation occurred within 1-2 days. This uptake is much greater than predicted by the ICRP's present or previous metabolic models for plutonium, but the excess is strongly corroborated by other data from this study.