The gamma activity of the radionuclides238U, 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" × 4" NaI (Tl) scintillation detector, the spectrum was analysed using a PC based 1k 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 Bqkg-1, respectively. Outdoor AED from 0.023 to 0.07 mSvy-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 Bql-1. The total annual effective doses due to 222Rn inhalation and ingestion range from 3.02 to 181.81μSvy-1, respectively, with an average value of 77.18μSvy-1.
Read full abstract