A strategy for a rapid radiological screening survey in large scale radiation accidents: A lesson from an individual survey after the fukushima daiichi nuclear power plant accidents

摘要

To establish a strategy for a rapid screening survey of surface contamination among a large number of people after nuclear power plant (NPP) accidents, the authors analyzed the measured surface contamination of subjects. From 12 March through 25 March 2011, a screening survey was conducted in a hospital on 336 subjects who had stayed within a 50-km radius of the Fukushima Daiichi NPPs. The count rates from measuring points of each subject were measured and compared in association with individual characteristics such as survey timing, gender, age, and distance between their location and the Fukushima Daiichi NPPs. The count rates from the head, hands, and clothes of subjects were correlated to the survey timing and distance by multiple regression analyses. When subjects were divided into two-by-two groups of survey timing and distance, the count rates from hands were not significantly different from those of the head and clothes. However, the count rates from the shoes of the subjects, excluding one group, were significantly higher than those of the other points. In addition, the count rate from a married couple showed a significant correlation. These findings suggest that measurement of at least two regions, such as one hand and one shoe, can be used as representative survey data in order to save surveillance time for a large number of people.