[en] The effect of γ radiation on the adsorption efficiency of silver impregnated and non-impregnated Amberlite IR-120 (H⁺) in the presence of air and water has been studied. The values of per cent adsorption of ¹³¹I on Ag-impregnated and non-impregnated Amberlite resins for different media are shown tabulated from which it is seen that for up to nearly 1 Mrad dose exposure there is negligible effect of radiation on non-impregnated Amberlite resin and at higher doses the capacity of this resin decreases, reaching 61% of the original value at about 17 Mrads. In the case of Ag-impregnated resin, there is no decrease in the capacity of resin even at 20 Mrad dose exposure. Also, Ag-impregnated and non-impregnated Amberlite resin when irradiated in presence of water show no decrease in the capacity. The results are discussed. (U.K.)