Assessment of the radiological hazards of sand sediments collected from streams and streamlets of the uranium deposit areas in West Khasi Hills District, Meghalaya, India

• Published in: Environmental earth sciences 2012-03, Vol.65 (6), p.1695-1703
• Main Authors: War, S. A., Nongkynrih, P., Khathing, D. T., Iongwai, P. S., Dkhar, L. M.
• Format: Article
• Language: English
• Subjects: Biogeosciences; Contaminated sediments; Creeks & streams; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Gamma rays; Geochemistry; Geology; Hills; Hydrology/Water Resources; Mineralization; Original Article; Radiation hazards; Radioactivity; Radioisotopes; Radium; Sand; Sediments; Streams; Terrestrial Pollution; Uranium
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-011-1147-0

Primordial radionuclides in sand sediments that are often used as constructing materials are one of the sources of radiation hazard in dwellings. Activity concentrations of the primordial radionuclides of 40 K, 226 Ra and 232 Th have been measured in sand sediments collected from streams and streamlets lying within and around the uranium mineralization deposit blocks of Kylleng-Pyndensohiong, Mawthabah Areas of West Khasi Hills District, Meghalaya, India. The technique of gamma-ray spectroscopy using a NaI(Tl) detector with a PC-based multi channel analyser was applied for determination of the activity concentrations. The activity of the sand sediments obtained in this study ranges from 95.3 to 1,088.8 Bq kg −1 for 40 K; 38.3 to 784.1 Bq kg −1 for 226 Ra and 78.0 to 316.1 Bq kg −1 for 232 Th. Sand sediments from two sampling locations lying within the mineralization zone show highest concentrations of these radionuclides. The radiological hazards of the sand sediments were calculated using various models given in the literature. The radium equivalent activity was found to be higher than the accepted standard criterion value of 370 Bq kg −1 and the values of external and internal hazard indices were also found to be higher than unity in these two sampling locations. Besides these two sampling locations, a sampling location lying at a nearby distance from the mineralization zone also exhibits hazard indices values greater than unity.