Estimation of radioactivity in soil and drinking water samples from Northern Gulbarga District of Karnataka

The gamma activity of the radionuclides ²³⁸U, ²³²Th and ⁴⁰K were measured in surface soil samples collected from 40 villages of Aland, Afzalpur, Ganaghapur and Kamalapur talukas of Northern Gulbarga district, Karnataka. The gamma activity of natural radionuclides were measured using 4'x4' NaI (Tl) scintillation detector, the spectrum was analysed using a PC based 1 k MCA (winTMCA 32 scinti SPEC) and the ²²²Rn activity concentrations in drinking water were determined by the Emanometry method. The activity of ²³⁸U, ²³²Th and ⁴⁰K was found to be in the range from 14.3 ± 0.3 to 64.5 ± 6.1, 15.4 ± 0.2 to 95.0 ± 4.1 and 21 ± 06 to 323 ± 09 Bq kg^-1, respectively. Outdoor AED from 0.023 to 0.07 mSv y^-1 and all the radiological hazards indices were well within the safe limit. The ²²²Rn activity in ground water is found to vary from 1.11 to 66.6 Bq l^-1. The total annual effective doses due to ²²²Rn inhalation and ingestion range from 3.02 to 181.81 μSv y^-1, respectively, with an average value of 77.18 μSv y^-1. (authors)