THE METABOLISM OF RADIONUCLIDES BY MARINE ORGANISMS. II. THE UPTAKE, ACCUMULATION, AND LOSS OF YTTRIUM⁹¹ BY MARINE FISH, AND THE IMPORTANCE OF SHORT-LIVED RADIONUCLIDES IN THE SEA

¹ Hawaii Marine Laboratory, University of Hawaii, Honolulu 14, Hawaii

Only about 2 per cent of an ingested dose of yttrium⁹¹ was left in Tilapia mossambica after two days. This is much less than the amount of strontium retained by Tilapia in similar experiments. About 40 per cent of the radioisotope remaining is found in the visceral organs, but the muscles retain about 30 per cent after 14 days. The skeleton retained less than 20 per cent, the integument about 10 per cent, and the gills 5 per cent. These findings are in marked contrast with those obtained with strontium⁸⁹ in similar experiments. Attention is focused on the fact that yttrium⁹¹ may have little direct effect on man compared with the possible effects of Sr⁹⁰, but the retention of this and other short-lived fission products in marine organisms having a brief life span may possibly affect the biota, and thus affect man indirectly.