FATE OF FALLOUT PLUTONIUM AND AMERICIUM IN THE ENVIRONMENT - SELECTEDEXAMPLES

At present, several isotopes of Pu and Am are in the biosphere as a re sult of above-ground nuclear weapons tests in the 1950s and 1960s. Eve n though their concentrations in most environmental samples are extrem ely low, they can be determined if methods are developed which allow c onvenient disintegration of very large samples before radiochemical an alysis. In this way, information on the long-term behavior of actinide s in the biosphere can be obtained under ideal natural conditions. The selected examples discussed here involve investigations on the follow ing: (1) the filter effect of coniferous trees for Pu and Am during th eir dry deposition; (2) the rate of vertical migration of Pu and Am in the different soil horizons of forest and grassland soils; (3) the tr ansfer of Pu and Am from soil to flour and bran from cereals; (4) the enrichment of Pu in some types of honey; (5) Pu and Am in the tissues of the general population in Germany.