Determination of radioactivity levels and associated hazards of coastal sediment from south east coast of Tamil Nadu with statistical approach

The concentration of U-238, Th-232 and K-40 in sediment samples collected from Thazhankudato Kodiyakkarai along the east coast of Tamil Nadu, India was measured using gamma-spectrometry. Measured mean activity concentrations are 3.3, 40.45 and 389.28 Bq kg(-1) for U-238, Th-232 and K-40, respectively. The average activity concentration of Th-232 is slightly higher than the world average value. The radiation hazards such as radium equivalent activity, absorbed gamma dose rates in air, the annual gonadal dose equivalent, annual effective dose equivalent, external hazard index, internal hazard index, representative level index and excess lifetime cancer risk associated with the radionuclides were calculated. Heat production rate of sediments and spatial distribution of radionuclides is studied. The multivariate statistical analysis, such as Pearson correlation, principal component and cluster analysis were applied to know the existing relation between radiological variables. From the analysis, the radioactivity levels in sediment samples do not pose any environmental health problem. Thus, the presented data provide a general background of the detectable radionuclides for the study area and can be helpful in future epidemiological studies.