DYNAMICS OF CHERNOBYL-FALLOUT RADIONUCLIDES IN SOIL SOLUTIONS OF FOREST ECOSYSTEMS

The long-term dynamics of radionuclides in soil solutions of various s ubhorizons of litter and mineral layer of soddy-podzolic sandy forest soils at 30-km zone around Chernobyl nuclear power station was studied . One year after the accident the relative contents of Sr-90, Ru-106, Cs-134,Cs-137 Ce-144 in soil solutions (radionuclide fractions in the liquid phase of soil) for the whole contaminated layer of soil were ve ry low (0.034-3.5%) and varied from one plot of zone to another becaus e of unequal physico-chemical properties of nuclear deposition. By 198 9 this parameter for radiocesium decreased 5-9 times and then varied s lightly The data indicate that since the accident three processes have taken place: radiocesium transfer from fallout into soluble forms, it s migration down the soil profile and fixation of radionuclide in orga nic-mineral layer of soil under the forest litter. (C) 1998 Elsevier S cience Ltd.