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The indoor 222Rn and 220Rn were measured by using deposition progeny sensors and single-entry pinhole dosimeter around Kolar Gold Fields of Karnataka state, India. The thirty different places were identified and fixed the dosimetry cups for the determination. The 222Rn and 220Rn concentrations of indoor environment range from 26.2 ± 1.3 to 138.4 ± 1.6 and 21.2 ± 0.8 to 133.3 ± 1.5 Bq/m3 with a mean value of 68.8 ± 1.6 and 61.8 ± 1.5 Bq/m3, respectively. The equivalent concentrations of 222Rn and 220Rn values vary from 0.9 ± 0.4 to 7.6 ± 1.1 and 6.8 ± 0.8 to 19.8 ± 1.8 Bq/m3 with a standard value of 4.3 ± 0.8 and 14.2 ± 1.3 Bq/m3, respectively. The values between the equilibrium factor between 222Rn, 220Rn, and their daughter were also calculated and found to be 0.23 and 0.07, respectively. The average annual intake of 222Rn, 220Rn, and their daughters' products is 2.28 mSv/y1, slightly below the global average of 2.4 mSv/y1 from all components. The data obtained compare average values in the world. [ABSTRACT FROM AUTHOR]

Radon activity concentration in soil gas has been studied in and around Bharathinagara, Mandya district (12° 13|| N and 77° 20|| E) using Solid State Nuclear Track Detectors with Twin cup dosimeter. The activity concentration of 222Rn in soil gas was studied at two depths. Radon in soil gas was found to increase with depth and decrease with increase in moisture content of the soil. Radon in soil gas was found to be higher in winter season which varies from 0.22 ± 0.01 to 1.31 ± 0.01 kBq/m3 with a Geometric mean value of 0.56 ± 0.01 kBq/m3 in 1 m depth and lower radon soil gas was found to be 0.16 ± 0.01 to 0.60 ± 0.01 kBq/m3 with a Geometric mean value of 0.30 ± 0.01 kBq/m3 in 0.5 m depth during summer season. The activity concentrations of radon soil gas from in and around Bharathinagara are lower compared to those in other parts of the world. [ABSTRACT FROM AUTHOR]

An extensive studies on the indoor activity concentrations of thoron, radon and their progeny in the granite region in the state of Karnataka, India, has been carried out since, 2007 in the scope of a lung cancer epidemiological study using solid-state nuclear track detector-based double-chamber dosemeters (LR-115, type II plastic track detector). Seventy-four dwellings of different types were selected for the measurement. The dosemeters containing SSNTD detectors were fixed 2 m above the floor. After an exposure time of 3 months (90 d), films were etched to reveal tracks. From the track density, the concentrations of radon and thoron were evaluated. The value of the indoor concentration of thoron and radon in the study area varies from 16 to 170 Bq m−3 and 18 to 300 Bq m−3 with medians of 66 and 82.3 Bq m−3, respectively, and that of their progeny varies from 1.8 to 24 mWL with a median of 3.6 mWL and 1.6 to 19.6 mWL, respectively. The concentrations of indoor thoron, radon and their progeny and their equivalent effective doses are discussed. [ABSTRACT FROM PUBLISHER]

Indoor radon and its progeny levels were measured during 2005-06 in Bangalore rural district and in Bangalore City by using Solid State Nuclear Track Detector (SSNTD)-based twin cup dosemeters, and the activity of radium present in soils and rocks was measured by using HPGe detector. Fifty dwellings of different types were chosen for the measurement. The dosimeters containing the detector (LR-115 Type II Film) used in each house were fixed 2 m above the floor. After an exposure time of 90 days, films were etched to reveal tracks. From the track density, the concentrations of radon were evaluated. The value of radon concentration in the indoor air near granite quarries varies from 55 to 300 Bq.m-3 with a median of 155 Bq.m-3 and its progeny varies from 0.24 to 19.6 mWL with a median of 8.4 mWL. In Bangalore City, the concentration of radon varies from 18.4 to 110 Bq.m-3 with a median of 45 Bq.m-3 and its progeny varies from 1.62 to 11.24 mWL with a median of 4.15 mWL. Higher concentrations of radon and its progeny were observed in granite quarries compared with Bangalore City. The main reason for the higher indoor radon and its progeny concentration is due to the mining activity and the types of the bedrock. The concentration of radon mainly depends on the activity of radium present in soils and rocks and the types of building materials used. The activity of radium varies in granitic regions of Bangalore rural district from 42.0 to 163.6 Bq.kg-1 with a median of 112.8 Bq.kg-1. The concentrations of indoor radon and its daughter products and equivalent effective dose are discussed. [ABSTRACT FROM AUTHOR]