PLACENTAL TRANSFER OF AMERICIUM AND PLUTONIUM IN MICE*

Publisher Website
Google Scholar
Abstract
Actinide element release to the environment and subsequent transfer through food chains to pregnant women may present a radiation hazard to fetuses in utero. To measure Am incorporation, 4 groups of pregnant mice were i.v. dosed with 4 concentrations of 243Am citrate in late pregnancy. Concentrations of 243Am in fetuses, placentas and maternal femur, liver, carcass and pelt were determined 48 h after injection. Doses were chosen so that the number of atoms of 243Am in each injected dose was equal to the number of atoms of 239Pu used earlier for transplacental movement. Am was incorporated into fetal tissue in lesser amounts (10-25 .times.) than Pu when i.v. administered to pregnant mice in equal atom amounts. At low dose levels the average fraction of the dose incorporated into the fetuses decreased as the dose to the pregnant mouse was increased. A similar pattern was noted for placentas and maternal femurs. Extrapolations from only low dose data are necessary to make reasonable and realistic estimates of the transplacental movement and fetal incorporation of environmental levels of actinide elements in man and other species.