Recent Progress in Decorporation of Plutonium, Americium and Thorium

The substances of choice for enhancing the excretion of transportable form of Pu, Am and Th from humans are the trisodium calcium or zinc salts of diethylenetriaminepentaacetic acid (DTPA). This paper summarises recent studies with laboratory animals which suggest that oral administration or infusion of DTPA would be an effective treatment for inhaled Pu and Am. The review is, however, devoted principally to progress achieved with siderophore analogues for the decorporation of Pu, Am and Th. Experimental evidence is presented which shows that the hydroxypyridinone derivative 3,4,3-LIHOPO, can be appreciably more effective than DTPA after their administration by intravenous injection, inhalation or wound contamination. Its use for humans must depend on the results of comprehensive toxicity testing, but the evidence available so far is encouraging. Potentially 3,4,3-LIHOPO represents a most significant advance for the decorporation of Pu, Am and Th. However, other siderophore analogues such as TREN-(3,2-HOPO) are worthy of further investigation.