Uptake of Fission Products and Neutron-Induced Radionuclides by the Clam

Abstract

Summary

A study of the uptake of 3 neutron-induced radionuclides (Zn⁶⁵, Fe⁵⁹, and Co⁶⁰) and a 2-month-old mixture of fission products by the clam demonstrated the ability of this marine animal rapidly to concentrate significant quantities of these radionuclides in both the shell and soft tissue. The uptake of radioactive material in the soft tissue is a metabolic incorporation, while the higher uptake by the shell appears to be a surface adsorption phenomenon. Rate of incorporation by the soft tissues was constant and was highest for the rare earth group of fission products. Uptake of Co⁶⁰, Zn⁶⁵, and Fe⁵⁹ was also constant but occurred at a much lower rate. Sr⁸⁹ and Ru^{103 106} were taken up only in equilibrium with the radioactive medium in the experimental interval studied. Further study with the radionuclide Co⁶⁰ indicated that rate of uptake varied as a power function with level of concentration of the radionuclide in the medium.

The ability of the clam to concentrate radioelements to a high degree makes it valuable as a biological indicator of radioactivity. It may be particularly useful in assessing contamination of marine areas with low levels of radioactivity.