The Carcinogenic Effects of Americium 241 and Plutonium 239 in the Rat

Abstract

A comparison has been made of the relative radiotoxicities of 239Pu and 241Am in terms of tumour production and, in particular, of bone tumour production. For approximately equivalent microcurie doses of the two nuclides, 241Am is far less effective in producing bone tumours than 239Pu. Fractionation of a single dose of 239Pu did not increase the number of tumours though there was a slight increase in the number of leukaemias. The fact that fewer bone tumours appear for equivalent microcurie doses of the two nuclides suggests that maximum permissible levels for 241Am might well be reconsidered.