FATE OF CESIUM IN THE ENVIRONMENT - DISTRIBUTION BETWEEN THE ABIOTIC AND BIOTIC COMPONENTS OF AQUATIC AND TERRESTRIAL ECOSYSTEMS

Interest in the fate of ratiocaesium in the environment has heightened considerably in recent years in the wake of the Chernobyl accident in 1986. The distribution of released Cs-137 and Cs-134 is related to th e chemical properties of Cs+, which generally dictate a high degree of mobility and bioavailability of the radionuclide. The partitioning of Cs+ between abiotic (i.e. soils, sediments, water) and biotic compone nts of terrestrial and aquatic ecosystem is complex and dependent on a number of factors, e.g. inorganic mineral content of the solid substr ates and rite abundance of monovalent cations. Direct biological Cs ac cumulation from the environment occurs readily in lower organisms and primary producers, e.g. micro-organisms and plants, Cs+ accumulation b y higher animals results predominantly from consumption of contaminate d foodstuffs, although direct inhalation/absorption from the environme nt may also occur. The evidence discussed here indicates that radiocae sium continues to be recirculated in biological systems for many years following a pulse of contamination.