Uptake and elimination of some radionuclides by eggs and fry of rainbow trout (II).

The uptake and elimination of radionuclides, 60Co, 131I, 137Cs, 144Ce and 106Ru by artificially fertilized eggs of rainbow trout were studied under laboratory conditions. The uptake and accumulation of 60Co and 137Cs were more rapid than those of the other radioduclides. Theoretical curves of uptake based on exponential model were fitted to get the parameters, rate of uptake (u), and turnover rate (β), using the least squares method. The concentration factors calculated as the ratio u/β were 7.4 for 60Co, 0.4 for 131I, 0.4 for 137Cs, 146 for 144Ce, 9.9 for 106RuNO-nitro, 12.5 for 106RuNO-nitrato and 6.3 for 106RuNO-binuclear complexes, respectively. The retention curves of 60Co and 131I consisted of the initial short component and the following long one, whereas one component for 144Ce until hatching. The elimination of 106Ru was much slower than that of the other radionuclides and more than 99% of 137Cs was eliminated in about 10 days. The significant fraction of 60Co, 131I, 137Cs and 144Ce in the egg was associated with the perivitelline fluid, while the most part of 106Ru in the egg was accumulated in the egg capsule. The accumulation of the radionuclides in the embryo was rather small.