Cesium (137Cs and 133Cs), Potassium and Rubidium in Macromycete Fungi and Sphagnum Plants

Abstract

Radiocesium (137Cs) released in the environment as result of nuclear weapons tests in the 1950s and 1960s, and later due to the Chernobyl accident in 1986, is still a critical fission product because of its long half-life of 30 years and its high fission yield. The study of the cesium radioisotope 137Cs is important, as production and emission rates are much higher than other radioisotopes. This chapter comprises results obtained in several experiments in Swedish forest ecosystems and aims to discuss the behavior of cesium isotopes (137Cs and 133Cs) and their counterparts potassium (K) and rubidium (Rb) in the ”soil-fungi-plants transfer“ system. The chapter consists of two parts: one mainly dealing with 137Cs, 133Cs, K and Rb in forest soil and macromycete fungi, and the other with the same isotopes in separate segments of Sphagnum plants. The bioavailability of radionuclides controls the ultimate exposure of living organisms and the ambient environment to these contaminants. Consequently, conceptually and methodologically, the understanding of bioavailability of radionuclides is a key issue in the field of radioecology. Soil-fungi-plants transfer is the first step by which 137Cs enters food chains.