Optimising the removal of inhaled plutonium and americium from the rat by administration of ZnDTPA in drinking water

1 The efficacy of ZnDTPA administered in drinking water has been investigated for removing 238 Pu and 241Am from the rat after their simultaneous inhalation as nitrates. 2 The continual administration of ZnDTPA 95 μmol kg-1 d-1 over a 21 d interval commencing 1 h after exposure reduced the 238Pu content of the lungs and total body to 2% and 8% of those in untreated animals; the corresponding values for 241Am were 3% and 5%. 3 The continual intakes of 950 μmol kg-1 d-1, intermittent intakes of 3600 μmol kg-1 d-1 and the repeated injection of 30 μmol kg-1 body weight were considered no more effective. 4 All orally administered concentrations of ZnDTPA, commencing 7 d after exposure, reduced the total body contents of 238Pu and 241Am to 17% and 20% of controls by 28 d. 5 Histopathological examination of the kidneys, liver and gastrointestinal tract showed no apparent effects of these treatment protocols. 6 It is concluded that the oral administration of ZnDTPA could be an effective treatment for the removal of inhaled transportable forms of Pu and Am after human exposure.