Abstract
The effects of chelation therapy by combined administration of Ca-DTPA and Zn-DTPA on the removal of inhaled “high-fired” plutonium oxide initiated at different times after exposure were examined in rats. After inhalation of plutonium oxide, the rats were divided into four groups of five. Chelation therapy was initiated 1 day after the inhalation in the first group, 7 days after in the second group, and 14 days after in the third group, the final group was a control (no DTPA treatment). A daily dose of 150μmol/kg of Ca-DTPA was administered by peritoneal injection for the first four days and subsequently, a same dose of Zn-DTPA was given orally for 26 days. In order to examine the effects of chelation therapy, we measured lung retention of plutonium with a phoswich detector, the amount of plutonium in excreta after Ca-DTPA injection, and the plutonium contents in various organs at the end of the experiment. The results indicate that DTPA therapy is not effective in removing “high-fired” plutonium oxide from the body.
