Population dose in the vicinity of closed Hungarian uranium mine

In order to determine the exposure to natural sources of radiation for people in the vicinity of remediated Hungarian uranium mine regional surveys were carried out. The surveys evaluated indoor radon concentrations and outdoor and indoor external gamma dose rates. Radon concentration has been measured with nuclear etched track detectors for 4 months in 129 houses in Kovágószolos and in 23 houses in Cserkút. In some houses measurements have been carried out for a year and the measurement results of the 4 months were corrected according to these. The corrected radon concentrations altered between 15 and 2314 Bq m(-3). An average of 257 Bq m(-3) in Kovágószolos and 125 Bq m(-3) in Cserkút was measured. The average was 434 Bq m(-3) for the 48 houses within 100 m of the passage of the former mine that is under the village of Kovágószolos. The higher values of Kovágószolos are likely to be the result of the influence of mining. The terrestrial gamma-ray dose rate was measured outdoors and indoors at these houses. Values of 139 (62-233) nGy h(-1) and 133 (93-275) nGy h(-1) were measured in Kovágószolos and Cserkút, respectively. The average annual effective doses for the two villages studied were 3 and 5 mSv y(-1), but the maximum value was 40 mSv y(-1).