PRESENTED BY”
Ramasamy V , Senthil S and Prasath M2

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ABSTRACT
There has been great concern about the health risks associated with the exposure due to the natural radioactivity present in coastal sediments all over the world. In this context, 35 intertidal sediment samples were collected from north east coast of Tamilnadu, India, in order to evaluate their natural radioactivity. The activity concentrations of natural radionuclides such as 238U, 232Th and 40K in sediment samples were determined by gamma ray spectrometer. The measured activity concentrations are ranged from BDL to 20.83±7.23 Bqkg-1 for 238U, BDL to 113.71±7.84 Bqkg-1 for 232Th and 210.27±24.42 to 434.32 Bqkg-1 for 40K. The mean values are compared with recommended and reported values. In order to evaluate the radiological hazard of the sediment, the absorbed dose rate and annual effective dose rate have been calculated and discussed. Averages of the calculated radiological parameters are within the recommended level. However, some extreme values are also observed in Devanampattinam (S6) and Mahabalipuram (S22) samples due to the presence of black sands.
Keywords: Natural radioactivity, Intertidal sediments, absorbed dose rate