The role of hydrogeochemistry in defining geopathogenic zones of natural radionuclides influence in the living environment of rural settlements

Abstract

In accordance to geological-structural characteristics of the terrain, in the phase of regional researches of uranium, different methods of geochemical prospection were applied. By hydrogeochemical prospection areas of natural radionuclides influence on living environment of rural settlements were defined. The locations were selected in which contents of U, 226Ra and 222Rn were increased in underground and ground water. The locations were selected in different geological environments: - Area of Vršac mountains which is built of crystalline schists with traces of granite. In them using Monte Carlo method geochemical radiation burden and cancer incidence were calculated per 100000 inhabitants. - In the area of tertiary sediments of Zaplanjski and Barbeški basins, anomalous concentrations of U, 226Ra and 222Rn were detected in springs, wells and surface flows. The determined secondary scattering halos of uranium, radium and radon in underground and surface water define radio ecological halos of rural settlements at selected locations. Research results contribute to the identification of geopathogenic zones of natural radionuclides influence on human population in living environment. The prospected area within regional researches includes the area of over 1000 km2. Several thousand samples were collected in which: contents of U, Ra and Rn, anioniccationic composition, content of gases and microelements, pH, Eh, Ep, mineralization, firmness, were determined in the purpose of monitoring natural radionuclides distribution and their deposition at favorable geochemical barriers. In accordance to World Health Organization criteria (WHO) for radionuclides concentrations in drinking water in radio ecological halos, water check points were isolated in which U,226Ra and 222Rn contents exceed allowed concentrations, which is shown in: tables, diagrams and hydrogeochemical maps (1:50000).