Radioactivity in the Mediterranean flora of the Kaštela Bay, Croatia.

This study refers to background activity concentrations of (238)U, (226)Ra, (232)Th, (208)Tl, (40)K, and (137)Cs in soil and plants of the Kaštela Bay, Croatia and related plant-soil concentration ratios (CR's). Fourteen different Mediterranean plant species growing in natural conditions have been included and were divided into three major plant groups (grasses and herbs, shrub, tree). Radionuclide activity concentrations were determined by means of high resolution gamma-ray spectrometry. Soil parameters (pH, electrical conductivity, and organic matter content) were also analysed. CR ranges were within one order of magnitude for (40)K (10(-2)-10(-1)), (238)U, and (226)Ra (10(-3)-10(-2)), and two orders of magnitude for (232)Th, (208)Tl, and (137)Cs (10(-4)-10(-2)). There was no statistical difference between the plant groups in radionuclide uptake. Overall statistical analyses indicated a moderate negative relationship between soil concentrations and CR values, and no relationship with soil parameters, except a negative one for (137)Cs. Comparison with literature showed more agreement with studies that were done in the Mediterranean than with ICRP and IAEA databases. Our data not only describe the natural radioactivity of the Bay, but also create a dataset that could be relevant for further radioecological assessments of the Kaštela Bay.