摘要:Effect of radon exposure on the activities of superoxide dismutase (SOD) in blood, kidney, liver and spleen of male Wistar rats were investigated. Radon exposure was carried out in a newly developed chamber with 226 Ra as the radon source. SOD activity, measured by the spin trap method using an electron spin resonance spectrometer, increased greatly in liver and kidney after 4 hour exposure whereas it decreased significantly after 16 hour exposure. Despite approximately same total doses by the radon exposure, the stimulated SOD activity after 4 hour exposure was not observed after 16 hour exposure in kidney, liver and spleen except blood, suggesting that the stimulating effect could last for a short period.