Comparison of Influences of Sediments and Sea Water on Accumulation of Radionuclides by Worms

Abstract

The accumulation and excretion of radionuclides by marine polychaete worms (Nereis japonica) were examined to know the influence of contaminated sediments on the contamination of marine organisms. The concentration factors of 60Co, 95Zr-95Nb, 106Rh-10GRh and 137Cs for unfed worms were 6, 4, 6 and 6 respectively, and they were similar to the concentration factors for unfed worms. The biological half lives of 60Co, 95Zr-95Nb and 106Ru-106Rh for fed worms were similar to each other (37, 32 and 35 days, respectively) except that of 137Cs (6 days), and all of them were a little shorter than those for unfed worms. The transfer ratios of radionuclides from sediments to worms were 5 per cent for 60Co, 0. 9 for 95Zr-95Nb, 0.6 for 106Ru-106Rh and 17.9 for 187Cs in cpm/g in regard to initial activity in sediments, and these figures were compared with the concentration factors to estimate the influence of sediments on the contamination of marine organisms. The obtained figures, we call the biological factor of the sediments, were 120, 440, 1000 and 30 for 60Co, 95Zr-95Nb, 106Ru-106Rh and 137Cs, respectively. © 1977, Journal of Radiation Research Editorial Committee. All rights reserved.