Radionuclides in terrestrial ecosystems of the zone of Kyshtym accident in the Urals

It was shown that along the Eastern Ural Radioactive Trace central axis, about 100 km in length, decrease of the 90Sr and 137Cs deposition densities in soil samples may be described as an exponential function. At the western and eastern periphery of the trace, 90Sr contents in soils approached to the background level due to global fallout. 90Sr and 137Cs concentrations in seeds of some herbaceous plants have been determined. The radionuclide concentrations and the resulting dose loads upon plant seeds showed an excess over the background level of about two or three orders of magnitude.