Comparison of influences of sediments and sea water on accumulation of radionuclides by marine organisms.

上 田泰司,中 村 良一,鈴 木 譲:放 射線医 学総合研究所 海洋放射生態学研究部 茨城県那珂湊市磯崎町3609 〒311-12 Marine organism/CF/Sediment The concentration factors of 106Ru-106Rh and 137Cs for a marine bivalve and a alga were investigated. Furthermore, the transfer ratio ([cpm/g of organism] /[cpm/g of sediment]) of these nuclides from contaminated sediments to organisms was examined . Then the concent ration factors were compared with the transfer ratio to know the relative influence of sea water and sediments on the contamination of marine organisms . The obtained figures, we call the biological factor of the sediments (BFS), were 70 and 160 for red alga and bivalve on 137Cs, and 5400 and 2900 for them in case of 106Ru-106Rh, respectively . These figures were comparable to those for annelid worm, 40 on 137Cs and 1000 on 106Ru-106Rh.