Indoor inhalation dose estimates due to radon and thoron in some areas of South-Western Punjab, India

LR-115 (type II)-based radonthoron discriminating twin-chamber dosemeters have been used for estimating radon (Rn-222) and thoron (Rn-220) concentrations in dwellings of south-western Punjab, India. The present study region has shown pronounced cases of cancer incidents in the public [Thakur, Rao, Rajwanshi, Parwana and Kumar (Epidemiological study of high cancer among rural agricultural community of Punjab in Northern India. Int J Environ Res Public Health 2008; 5(5):399407) and Kumar et al. (Risk assessment for natural uranium in subsurface water of Punjab state, India. Hum Ecol Risk Assess 2011;17:38193)]. Radon being a carcinogen has been monitored in some dwellings selected randomly in the study area. Results show that the values of radon (Rn-222) varied from 21 to 79 Bq m(3), with a geometric mean of 45 Bq m(3) [geometric standard deviation (GSD 1.39)], and those of thoron (Rn-220) from minimum detection level to 58 Bq m(3) with a geometric mean of 19 Bq m(3) (GSD 1.88). Bare card data are used for computing the progeny concentration by deriving the equilibrium factor (F) using a root finding method [Mayya, Eappen and Nambi (Methodology for mixed field inhalation dosimetry in monazite areas using a twin-cup dosemeter with three track detectors. Radiat Prot Dosim 1998;77(3):17784)]. Inhalation doses have been calculated and compared using UNSCEAR equilibrium factors and by using the calculated F-values. The results show satisfactory comparison between the values.