A STUDY ON THE RADIATION DOSE DUE TO DISSOLVED 222RN IN WATER SAMPLES OF MANDYA CITY, KARNATAKA, INDIA

Abstract

Abstract Measurement of dissolved radon concentrations in the water samples collected from selected borewells (depth ~300 ft), wells (depth ~25 ft) and overhead tanks (height ~30 ft) of Mandya city, Karnataka, India, has been carried out by using Emanometry method. The radon concentrations in the waters of borewell, well and overhead tank ranges from 1.5 ± 0.1 to 102.8 ± 5.1, 1.3 ± 0.1 to 3.8 ± 0.4 and 2.5 ± 0.2 to 9.7 ± 1.1 Bq l−1 with the mean values of 16.8, 2.5 and 6.2 Bq l−1, respectively. Majority of borewell water samples showed higher concentrations of dissolved 222Rn compared to waters of well and overhead tank. The overall mean value of dissolved radon concentration of 12.2 Bq l−1 is found to be close to the maximum contaminant level of 11 Bq l−1 suggested by US Environment Protection Agency. The physicochemical parameters like pH, TDS and conductivity were also measured, and dependence of dissolved 222Rn on these parameters has been studied. Using the mean value of dissolved radon concentration, a new attempt has been made to compute the doses imparted to different organs and tissues of the human body. Dosimetric calculations showed that stomach and small intestine receive greater doses due to dissolved radon compared to other organs.