RADIOECOLOGY MONITORING SYSTEM FOR MOUNTINE AREAS OF THE TISZA RIVER BASIN (TRANSCARPATHIA, UKRAINE)

Abstract

Regularities of distribution, migration and accumulation of natural gamma-active nuclides 40K, series of uranium 238U (214Pb, 214Bi) and thorium 232Th (212Pb, 212Bi, 228Ac, 208Tl), as well as technogenic 137Cs in the bottom sediments of the Tisza region in Transcarpathia (Ukraine) have been established. It is shown that the content of these radionuclides in the bottom sediments is relatively stable along the entire length of the Tisza river and is proportional to the level of its siltation, which largely depends on the morphology of the river. It was found that the total specific activity of natural gamma-active radionuclides (excluding 40K) in bottom sediments ranges from 110…139.7 Bq/kg. Areas of accumulation of gamma-active nuclides in the bottom sediments of the studied river have been identified, and the probable causes of this phenomenon have been substantiated. The averaged data of the content of specific activity of radionuclides in the bottom sediments of the Tisza river were used for mapping and forecasting of migration processes, as well as for identification of the studied sections of the river taking into account the geochemical features of the region.