MEASUREMENT OF INDOOR RADON-THORON IN AIR AND EXHALATION FROM SOIL IN THE ENVIRONMENT OF WESTERN HARYANA, INDIA.

Abstract

Measurement of indoor radon and thoron is important because the inhalation of radon-thoron and their daughters contributes more than 50 % of the total dose from natural sources. One of the important parameters to find out the contribution of soil and building materials towards indoor radon is radon exhalation rates, which can be used for estimation of indoor radon levels. The indoor radon and thoron levels from the air and radon exhalation rates from soil samples collected from two districts (Hisar and Fatehabad) of Western Haryana are measured using pin-hole-based radon-thoron dosimeter and LR-115 solid-state nuclear track detector by canister technique. The results show that the indoor radon and thoron levels from Hisar district varied from 11 to 112 and 11 to 80 Bq m-3, while for Fatehabad district from 5 to 24 and 59 to 105 Bq m-3, respectively, in summer season. In winter season, indoor radon and thoron levels from Hisar district varied from 15 to 43 and 32 to 102 Bq m-3, while for Fatehabad district from 18 to 31 and 11 to 80 Bq m-3, respectively. The indoor radon levels of 95 % locations lie well below the limit recommended by International Commission of Radiation Protection, 2011. The radon mass exhalation rate varied from 6 to 56 mBq kg-1 h-1 The radon mass exhalation rates from the soil samples were lower than the worldwide average, i.e. 56 mBq kg-1 h-1 There exists a poor correlation between indoor radon and exhalation rates. More investigations of measurement of radionuclide contents from rock and stone of study area can improve the understanding.