BIOKINETICS OF 3 INDUSTRIAL PLUTONIUM NITRATE MATERIALS - IMPLICATIONS FOR HUMAN EXPOSURE

This study describes the biokinetics of three plutonium (Pu) nitrate b earing materials formed in industry and uses transfer rates to blood t o derive ALIs and doses per unit intake. The behaviour of these was pr edicted by combining transfer rates determined in rat experiments with a mucociliary clearance function obtained from human volunteers expos ed to fused aluminosilicate particles. It is concluded that the biokin etics of Pu nitrate can be best described as between a Class W and Y c ompound, with aged residues being very similar to Class Y. Calculation s have demonstrated that despite the beta emitting plutonium being in great excess, the doses per unit intake are dominated by the alpha emi tting radionuclides. The adoption of the most recent ICRP recommendati ons will reduce the calculated doses per unit intake (CEDE vs. CED) an d hence the ALI may increase. The new lung model, currently in its fin al development, is unlikely to alter these predictions substantially.