抄録
We found loopholes of laws and regulations for supervising radioactive materials. It is not obliged to measure the soil radioactivity of the sites that were formerly used as scientific or engineering institutes, or hospitals with a radioactive material control area. If the former institutes or hospitals made studies with radioactive materials before the enforcement of the law concerning prevention from radiation hazards due to isotopes and its detailed regulations, it is concluded that there was the period when the radioactive materials were not under management. If it is found that the radioactive materials were applied at the former site before the enforcement of the related laws and regulations, the radioactivity in the soil of the redeveloped area should be examined, which should be obliged by some laws or regulations.
