Residential radon exposure in Astana and Aqsu, Kazakhstan.

A pilot study was carried out to measure indoor radon concentrations in a uranium mining area of northern Kazakstan. A total of 80 places at kindergartens, elementary schools, and dwellings were selected in Aqsu village and Astana city as the uranium mining area and background area for comparison, respectively. In Astana and Aqsu, the 3-month radon concentrations from late summer to autumn in 2022 were measured using the RADUET passive radon detectors. Radon concentrations ranged from 4 to >2,000 Bq m-3 (mean ± standard deviation: 290 ± 173 Bq m-3) throughout the study areas. The concentrations were higher in Aqsu, and 70% of the dwellings there exceeded 300 Bq m-3, whereas only 5% of them exceeded 300 Bq m-3 in Astana. Accordingly, the new dose conversion factor for radon recommended by ICRP Publication 137 was applied to calculate the annual effective dose. The annual effective dose from the inhalation of radon was estimated to be 3.6 ± 4.6 mSv y-1 for Astana and 23.7 ± 15.6 mSv y-1, for Aqsu, which are both higher than the world average value of 2.5 mSv y-1.