Radium concentrations in Adriatic coastal area and their dependence on circulation of sea

The study was conducted by the Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb as a part of an extensive monitoring program of the Croatian environment. The program also includes the Adriatic region with particular emphasis on coastal seawater of northern Adriatic, one of Croatia?s critical locations due to remarkable industrial activities and technologically enhanced radioactivity. The paper deals with the assessment of 226Ra levels in the bay of Croatian coast where the quality of sea water and its environment may be endangered by the operation of a coal-fired power plant located close to the seaside. The aim was to determine vertical and horizontal distribution of radium and its dependence on the seawater currents at different sea depths. The level of 226Ra activity was assessed in seawater four times a year, at three locations and at two sea depths. According to the results based on the analyses of samples collected at the sea surface and at the depth of 3 m, seasonal variations were not found at any location. Calculated correlations showed high conformity of the values by separate locations and samplings.