Uptake and Concentration of Radioisotopes by Certain Fresh Water Fish

The uptake and concentration of 60Co and 65Zn by different organs of Oreochromis nilocicus fish, collected from the Egyptian Ismailia canal fresh water stream have been investigated. The concentration factors of these isotopes were found to increase with increasing contact time with with water, labeled with radioisotopes, higher than two up to six day for 60Co or nine day for 65Zn. Viscera were found to concentrate higher activity than do by bone or flesh especially in case of 65Zn where maximum concentration factor of 1700 was obtained. Values of radioactivity remained in contaminated fish organs at different contact times with fresh water, revealed that release of 60Co and 65Zn from fish bones, flesh and viscera takes place in a single step. The half-lives both radioisotopes in the fish organs were determined