Studies on concentration of minor stable elements in marine environmental samples

Information on the physico-chemical state and quantity of stable elements in marine environments is frequently required to analyze the radioecological behavior of radionuclides released from nuclear facilities into the sea. In this work, determination of stable Mn, Fe, Co, Zn, Zr, Rb, Cs and some rare earth elements (Ce, Eu, Tb, Yb and Lu) in seawater and marine organisms was carried out and the concentration factors were estimated. Seawater and marine organisms were collected on the seashore of Ibaraki Prefecture and analysed by means of neutron activation analysis or atomic absorption spectrometry depending on the elements or samples. Average concentration factors of the rare earth elements by marine organisms are estimated as 3 x 101: muscle of fish, 5 x 102: soft part of clams, and 2 x 102: algae, respectively. Concentration factors by muscle of fishes were 103: Fe, 2 x 102: Co, 5 x 102: Zn, and 5 x 101: Cs, and those by soft part of shellfishes were 104: Fe, 103: Co, 2 x 103: Zn, and 101: Cs, whereas those by algae were 2 x 104: Fe, 5 x 102: Co, 103: Zn, and 3 x 101: Cs, respectively. The high concentration factors for numerous stable elements by shellfishes and algae suggested their suitabilities to the indicator organisms for monitoring of marine pollution by these heavy metals and corresponding radioisotopes and also their significant contribution to the internal radiation exposure to man as radioactive seafoods. (author)