Browsing by Author "Turyahabwa, Evarist Rutahweire Silver"

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    Gamma ray activity levels and radiological hazard indices of Radionuclides in mine tailings from selected mines in Southwestern Uganda.
    (Kyambogo University [unpublished work], 2016-01) Turyahabwa, Evarist Rutahweire Silver
    This study was designed to determine and compare the specific activity levels and the radiological hazard indices of gamma ray emitting radionuclides in mine tailings from three selected mines in Southwestern Uganda. This was achieved by analyzing 72 soil and rock mine tailing samples using the GDM 20 Nal(TI) detector. The specific activities of the principal primordial radionucides of 238U, 232Th and 4°K in the samples were measured. The values obtained were used to determine the absorbed dose rates, the annual effective dose rates, the radium equivalent activity, external and internal hazard index and the excess lifetime cancer risk. The mean specific activities of 238U, 232Th and 4°K in mine tailings at 90% confidence level ranged from 23±14 Bqkg-1 to 59±16 Bqkg-1 for 238U, 49±39 Bqkg-1 to 244±19 Bqkg-1 for 232Th, and 226±232 Bqkg-1 to 893±167 Bqkg-1 for 4°K. The mean outdoor and indoor absorbed dose rates in air for Mashonga, Kikagati and B utare were (181±36 nGyh-1 and 338±67 nGyh-1 ), (167±23 nGyh-1 and 310±47 nGyh-1 ) and (192±16 nGyh-1 and 355±32 nGyh-1 ) respectively for waste soil samples and (67±50 nGyh-1and 127±102 nGyh-1 ), (85±37 nGyh-1 and 159±80 nGyh-1 ) and (115±33 nGyh-1 and 215±66 nGyh-1 ) respectively for waste rock samples. The ratio of the mean indoor to outdoor absorbed dose rates in all the samples was 1.9 but this was 36% higher than the world average. The total annual effective dose rates, radium equivalent activities, external and internal hazard indices for waste soil samples were above the maximum permissible limits recommended for members of the public. Potential radiological hazards on miners and the people living in the neighborhood of the sites due to external irradiation are significant. There is need to improve waste management practices in the mining sites in order to prevent health hazards associated with the radionuclides in the mine tailings.