Toxicity of uranium and plutonium to the developing embryos of fish

The radiological and chemical toxicity of plutonium and uranium to the developing embryos of fish was investigated using eggs from carp, Cyprinus carpio, and fathead minnows, Pimephales promelas. Freshly fertilized eggs were developed in solutions containing high specific activity 238Pu or 232U or low specific activity 244Pu, 235U, or 238U. Quantitative tests to determine the penetration of these elements through the chorion indicated that plutonium accumulated in the contents of carp eggs reached a maximum concentration factor of approximately 3.0 at hatching. Autoradiographs of 16 μ egg sections showed that plutonium was uniformly distributed in the egg volume. Uranium localized in the yolk material, and the concentration factor in the yolk sac remained constant during development at approximately 3.3. Doses from 238Pu which affected hatchability of the eggs were estimated to be 1.6 x 104 rads and 9.7 x 103 rads for C. carpio and P. promelas, respectively; doses from 232U were 1.3 x 104 rads for C. carpio and 2.7 x 103 rads for P. promelas. A greater number of abnormal larvae than in control groups was produced by 238Pu doses of 4.3 x 103 rads to carp and 5.7 x 102 rads to fathead minnows; 3.2 x 103 rads and 2.7 x 102 rads were estimated from 232U. Eggs that were incubated in 20 ppM 244Pu did not hatch. This mortality may have been the result of chemical toxicity of plutonium. Concentrations of 60 ppM of 235U and 238U did not affect egg hatching. Based on these data, concentrations in fish eggs were calculated for representative concentrations of uranium and plutonium in waste waters and the corresponding dose levels are below those levels at which observable effects begin to occur