Characterization of 222Rn and meteorological parameters in Uro houses at South Kordofan state

Abstract

This study was carried out to assess and map indoor radon concentration and to estimate radiation dose in Uro town in Sudan's South Kordofan state. A portable radon meter (RRA-01M-03), equipped with simple sensors of meteorological parameters has been used for carrying out radon measurement. The annual absorbed dose from the corresponding measured radon concentration was calculated using dose rate conversion factors of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The corresponding annual effective dose and equivalent dose to the lungs were estimated. Measured activity concentrations of 222Rn, annual absorbed dose, annual effective dose and equivalent dose to the lungs were found in the range 20–4482 Bq/m3, 0.32–70.67 mSv/y, 0.76–169.61 mSv−y and 0.16 × 10−7 to 35,856 × 3.5856 × 10−11 mSv−y, with geometric mean 109.43 Bq/m3, 1.73, 4.16 and 1.1 × 10−7 mSv−y, respectively. Upon comparing the results with global data, it was found with the exception of six samples, the obtained values fall far below the action level of 200–600 Bq/m3 recommended by the International Commission on Radiological Protection. However, the geometric mean is higher than the reported average global indoor radon concentration. Meteorological parameters were measured and no correlation was noted between radon concentration and these parameters. The overall annual effective dose was higher than the UNSCEAR recommended reference dose level of 1.0 mSv−y.