The Accumulation of Y90 from an Equilibrium Mixture of Sr90‐Y90 by Artemia salina (L.)1

Abstract

Artemia salina (L.) was chosen as a representative organism in the second trophic level for studying one phase of the process of transfer of radionuclides through a marine food chain. Adult Artemia were cultured in filtered sea water which contained Sr90‐Y90. They were not fed during the experiment which lasted 92 hours. They were removed at intervals, washed, and their radioactivity determined with an end‐window counter. At 16 hours the concentration of radioactivity in the Artemia was about 40 times that of an equal weight of sea water. The radioactivity decayed at a rate which was similar to the decay rate of Y90. It was estimated that only about 5 per cent of the activity remaining at secular equilibrium was due to Sr90, the remainder being Y90. This biological fractionation of Sr90‐Y90 may affect the transfer of these hazardous nuclides through food chains leading to human food. The fractionation of these nuclides by laboratory glassware is briefly discussed.