Assessment of gamma radiation and associated radiation hazards in coastal sediments of south east coast of Tamilnadu, India with statistical approach.

Gamma spectroscopy was performed to determine the concentrations of Ra, Th and K in sediment samples collected from Periyakalapet to Parangaipettai, East coast of Tamilnadu. The activity concentrations were determined by direct counting using a hyper pure germanium (HPGe) detector inter phased with a multi channel analyzer (MCA). The average activity concentrations of the corresponding nuclides were 30.81 Bq kg for Ra, 85.67 Bq kg for Th and 425.72 Bq kg for K. The average activity concentration of Th and K are slightly higher and Ra is lower than world average values. The radiation hazard indices namely Radium Equivalent Activity (Ra) Absorbed Gamma Dose Rate (D), Annual Effective Dose Rate (H), Representative Level Index (RLI), Annual Gonadal Dose Equivalent (AGDE), Internal Hazard Index (H) and External Hazard index (H) are calculated and compared with the previously reported data. The extracted values are comparable to the recommended values and they all fall within the safety limits. Hence harmful radiation effects are not posed to the public and tourists going to the beaches for recreation or to the fishermen involved in their activities in the area as a result of the natural radioactivity of sediments. Multivariate Statistical analyses were carried out between the parameters obtained from the radioactivity to know the existing relations and to study the spatial distribution of radionuclides.