Quantification of an alpha flux based radiological dose from seasonal exposure to 222Rn, 220Rn and their different EEC species

This study summarizes the seasonal experimental data on the activity concentrations of indoor Rn-222 (Radon), Rn-220 (Thoron) and their progeny in Mansa and Muktsar districts of Punjab (India) using LR-115 solid state nuclear track detector based time integrated pin-hole cup dosimeters and deposition based progeny sensors for the assessment of radiological dose. The indoor Rn-222 concentration was observed higher in the rainy and winter seasons while Rn-220 concentration was observed higher in the winter season. However, Equilibrium Equivalent Concentrations (EECs) of Rn-222 and Rn-220 exhibited distinct seasonal behaviour unlike their parent nuclides. The average equilibrium factors for Rn-222 (F-Rn) and Rn-220 (F-Tn) were found 0.47 +/- 0.1 and 0.05 +/- 0.01, respectively. The annual arithmetic means of unattached fractions of Rn-222 (f(rho)(Rn)) and Rn-220(f(rho)(Tn)) were found to be 0.09 +/- 0.02 and 0.10 +/- 0.02, respectively. The attachment rate (X-Rn) and attachment rate coefficients (beta) of Rn-222 progeny were also calculated to understand the proper behaviour of progeny species in the region. A new alpha flux based technique has been proposed and used for the assessment of absorbed dose rate and annual effective dose rate for radiation protection purpose.