Effect of radionuclides cesium-137 and strontium-90 on oxidation of ascorbic acid by methylene blue in the presence of copper(II) ions

We have observed the different effects of the radionuclides Cs-137 and Sr-90 on the rate of oxidation of ascorbic acid by methylene blue in the presence of copper(II) aquo ions: introduction of Cs-137 into the solution leads to retardation of this process, while introduction of Sr-90 leads to acceleration. We discuss possible mechanisms for such different effects.