Radon exhalation rates from stone and soil samples of Aravali hills in India

Background: The most popular building materials are soil bricks and different types of stones. Radon is released into ambient air from soil and stones due to ubiquitous uranium and radium in them, thus increasing the airborne radon concentration. The radioactivity in soils is related to radioactivity in the rocks from which the soil is formed. In the present investigation, the radon emanated from soil and stone samples collected from different locations of Aravali range of hills in the Haryana state of Northern India has been estimated. Materials and Methods: For the measurement of radon concentration emanated from these samples, alpha-sensitive LR-115 type II plastic track detectors have been used. The alpha particles emitted from the radon form tracks in these detectors. After chemical etching the track density of registered tracks is used to calculate radon concentration and exhalation rates of radon using required formulae. Results: The radon concentration in stone samples collected from Aravali range of hills varied from 729 Bq m(-3) to 1958 Bq m(-3) with an average of 1440 +/- 134 Bq m(-3) whereas it varied from 806 Bq m(-3) to 1325 Bq m(-3) with an average of 1040 +/- 101 Bq m(-3) in case of soil samples. Based upon the data, the mass and the surface exhalation rates of radon emanated from them have also been calculated. Conclusion: The measurements indicate normal to some higher levels of radon concentration emanated from the samples collected from Aravali range of hills of north India. Iran. J. Radiat. Res., 2011; 9(1): 57-61