We studied on the characteristics of changes in antioxidant function of mice brains at 4 h to 7 days after low-dose X-ray (0.1 to 2.0 Gy) irradiation, and the combination effect of this and administration of ascorbic acid (500 mg/kg body weight), an antioxidant enzyme. As a result, low-dose irradiation mostly showed decrease in lipid peroxide levels, increase in superoxide dismutase (SOD) activities and heat shock protein (HSP) levels. In addition, the combined use of 0.5 Gy irradiation with ascorbic acid administration showed a significant decrease in lipid peroxide level, suggesting the combined effect of antioxidant.

Internal education and training on the safety management of small quantities of nuclear material are introduced along with recent trends in the surrounding area. Due to regulatory changes, nuclear material management standards have become stricter. This article outlines the concepts and content of education and training for users, officers, and administrators working with small quantities of nuclear material started at the universities to which the authors belong.

The Fukushima Dai-ichi Nuclear Power Plant Accident released large quantities of radionuclides into the atmosphere, with subsequent fallout onto wide area of land surface in Fukushima and its neighboring prefectures. Because approximately 70％ of the radiocaesium deposited on land was in forest areas, an analysis of the spatial distribution and transfer of radiocaesium in forested landscapes is necessary to diagnose both the environmental impacts of the accident and the environmental recovery from radioactive contamination. This article summarizes research findings from an investigation into radiocaesium dynamics in terrestrial environments in and around Fukushima prefecture, and gives prospects in future prediction of impacts and recovery.

Radiocesium released from the Fukushima Dai-ichi Nuclear Power Plant migrates very slowly in soil as if it is immobilized at soil surface. The immobility of radiocesium is controlled by selective adsorption of radiocesium on the negatively-charged sites in phyllosilicates. This article introduces the principle and methodology to determine the selective adsorption site. Furthermore, this lecture introduces an example of the prediction model for soil-to-plant transfer of radiocesium by using the capacity of the selective adsorption site as an explanatory variable.