Exploring seasonal changes in radon/thoron and progeny concentration: a case study in south-west Punjab

An extensive investigation was undertaken to assess indoor radon and thoron concentrations in 50 residential dwellings of Fatehgarh district of Punjab. Single entry pin-hole dosimeter was employed at the dwellings for estimation of concentration of radon and thoron. For estimation of attached and unattached progeny concentration, direct radon and thoron progeny sensors (DRPS/ DTPS and wire-mesh DRPS/DTPS) were used. Continuous monitoring of radon/thoron and their progeny concentrations was conducted for a duration spanning from April 2022 to April 2023, encompassing all four seasons. Based on the obtained results regarding the concentration of these radioactive gases, additional assessments were made, including the estimation of the equilibrium factor, fine fraction inhalation doses through both mouth and nose, and the total annual absorbed dose. Based on the findings of this study, it can be inferred that the highest concentrations of these radioactive gases were observed during the winter season, while the lowest concentrations were recorded during the summer season. Furthermore, the average concentration values for these gases were found to be below the ICRP action level limit of 200–300 Bq/m³ for all seasons.