Activity of 226Ra, 232Th and 40K in riverine environs and evaluation of radiological hazards
This paper discusses the results of systematic measurement of activity concentrations of 226Ra, 232Th and 40K in riverine samples of river Sharavathi, one of the major rivers of coastal Karnataka in India. Activity concentrations of 226Ra, 232Th and 40K in soil, sediment and rock were measured by Na(I) Tl gamma-ray spectrometry. To assess the radiological hazards of the natural radioactivity in the samples, absorbed gamma-dose rates in air, radium equivalent activity, representative level index, external hazard index and internal hazard index values associated with the radionuclides were calculated and compared with the international recommended values. The representative level index (Igr) values are high in soil and sediment samples. The external hazard index (Hex) and internal hazard index (Hin) values are low in rock samples of the Sharavathi River.
Keywords: natural radioactivity, rivers, soil, sediment, rock, radiation hazards, low radiation, India