Geochemia poczarnobylskiego cezu w glebach i roślinach anomalii opolskiej

Abstract

GEOCHEMISTRY OF POST-CHERNOBYL CAESIUM IN SOILS AND PLANTS IN OPOLE REGION Summary The accident at the of nuclear power plant at Chernobyl resulted in surface contamination of soils across large areas of Europe, including Poland. Mappings aimed of defining the scale of contamination were done in Poland in 1993, using gamma spectrometry. Maps of uranium, thorium, potassium, post-Chernobyl caesium (a sum of radioisotopes 134Cs + 137Cs) content and of gamma dose rate have been published in scale 1 : 750,000 basing on data from over 20,000 measurement points, located regularly each 1000 m along traverse lines (40 traverses) oriented N-S and spaced each 15”longitude in the whole country. In Poland several areas with increased concentration of caesium isotopes were identified. The largest one is so the called Opole anomaly located in the south-western Poland. In 1994 in the area of Opole anomaly were realised the precise mappings in 1 : 100,000 scale. During these studies the first geochemical soil profiles of caesium distribution and of caesium bioaccumulation in grasses were obtained. The results shown that in 1994, 8 years after the fall-out of radioactive caesium, 80–90% of it resides in the top, 10 cm thick, layer of soil in turn leading to a higher caesium content in grasses. In 1996–1997 the spectrometric analyses and studies of distribution of natural and artificial radioisotopes in soil profiles were repeated in the Opole region. They included also concentration analyses of post-Chernobyl caesium within plants and duffs. In 189 soil samples the concentrations of caesium radioisotopes: (137Cs and 134Cs) and of natural radionuclides were determined. Results of radioecological analysis indicate a lack of caesium radioisotope concentrations higher than doses accepted for edible crops. Thus, the studied regions, although the most contaminated in the whole Poland area, are not areas of radiological hazard.