Development of technology on environmental monitoring, (6)

In the UNSCEAR 1982 Report, it was estimated that inhalation of radon and its short-lived decay products accounts on average for about one half of the effective dose equivalent from all natural sources of radiation. Furthermore, environmental monitoring in the vicinity of waste rock dumps from past uranium mining activities requires environmental radon monitoring. Therefore, radon measurements in resident area in the vicinity of Ningyo Toge Works have been carried out by electrostatic collection method. According to the monitoring experience, seasonal variation such as relatively high radon concentration in summer, and specified area which may have slightly high radon background have been determined. Furthermore, radon calibration chamber which consists of chamber, blower and gas loop has been instrumented. (author)