A study on environmental pollution caused by radioactive substances and its countermeasure techniques (part 1), present situation of radioactive pollution and decontamination

Fukushima and the neighboring area have been polluted by the accident of the nuclear plant and there are some locally contaminated areas called as "hot spot". Although the radioactive substance that piled up on the road or the roof of buildings is moved away by the rain, the decontamination is indispensable to prompt reduction. Especially, the decontamination in urban areas is an urgent subject. In present research, in order to clarify the actual condition of contamination, the radioactive concentration of the soil and the plant in Koriyama city was measured. It turned out that the radioactive concentration of soil or plants were heavily polluted by caesium-134 and 137, and iodine-131 was already disappeared by its lifetime. Especially, cesium-134 + 137 was ranged 3400 Bq/kg at the surface of soil in garden, however, it was remarkably decreased in the deeper point at 10cm and ranged 23 Bq/kg, and we cannot detect the cesium at 15cm. It is necessary for people in Fukushima to decontaminate for reducing radioactivity level. And it turned out that the evergreen plants have been polluted at high radioactive concentration and decontamination by cutting down the plant was decreased by 14% average. Most of radioactive material is removed by removing soils.