The intestinal absorption of plutonium nitrate is increased approximately 700-fold when chelated with DTPA. Within 2 days, virtually all of the absorbed plutonium-DTPA complex is excreted in the urine. Thus, plutonium retention in the liver and skeleton is quite low, but more than twice as high as when DTPA is not present. Citrate is less effective than DTPA in increasing absorption, but more effective in increasing retention, Since both absorption and retention are increased by chelation, consideration must be given to this added risk when therapeutic procedures result in the chelation of plutonium entering the GI tract.