Temporal Variation in Indoor Air and Soil-Gas Radon Concentrations

Airborne indoor radon activity ranged from 0.0 to 67.10 Bq/m3 with an average value of 20.71 Bq/m3 over a period of 48 hours, which was very less compared to the respective action level values of 148 and 100 Bq/m3 prescribed by EPA (1991) and WHO (2009). The radon progeny (PAEC) concentration varied from 0.0 to 7.25 mWL (average: 2.24 ± 2.11 mWL) while their resultant lifetime fatality risk varied from 0.0 x 10−4 to 0.90 x 10−4 (average: 0.28 x 10−4). The study area is categorized as low radon risk area (