Abstract
CaSO4: Tm thermoluminescence dosimeters and radiophotoluminescence dosimeters were used to carry out an investigation of indoor and outdoor environmental radiation in Akita Prefecture, Japan, during the period from April to October 1994. The results showed that the average absorbed-dose rate in air from outdoor terrestrial gamma-radiation was 38.8nGy h-1 with a range of 26.6-50.2nGy h-1. The indoor average absorbed-dose rate of wooden houses was 40.2nGy h-1 with a range of 29.5-50.4nGy h-1, and for concrete buildings it was 55.3nGy h-1 with a range of 41.7-66.9nGy h-1. The indoor weighted average absorbed-dose rate of concrete buildings was 42.9nGy h-1. Among different geological areas, the gamma-radiation absorbed-dose rate of andesite was the highest (50.2nGy h-1), and alluvium was the lowest (30.3nGy h-1). As for the results of measurement the two kinds of dosimeters were quite similar. Eighty-two percent of the results of measurement from twenty-eight monitoring sites where the two kinds of dosimeters were used coincided within ±5%, and there were only two sites where the difference was larger than 10%; deviations were +10% and +11%, respectively. These results indicated that the radiophotoluminescence dosimeter is also suitable for the measurement of environmental radiation.
