Determination of Natural Radioactivity Levels and Evaluation of Radiological Hazards in Coastal Sediment of Kerala with Statistical Approach

High background radiation areas (HBRAs) have been identified in coastal locations of Kerala. As a result, the radiation protection of the inhabitants is a significant concern in this region. The sediment samples were collected from the Vellanathuruthu to Thumpoly regions of the Kerala Coast, which have been recognised as High Background Radiation Areas (HBRA). Sediment radionuclide concentrations were measured using a NaI (Tl) detector. The activity values and mean (in brackets) values for238U, 232Th, and 40K are 78.92 to 1493 Bq kg−1 (552.63), 94.76 to 2856.46 (851.24) Bq kg−1 and 30 to 2399.20 (678.61) Bq kg−1 and average radionuclide concentration exceed the recommended level which is significantly more than 35 Bq kg−1, 30 Bq kg−1 and400 Bq kg−1respectively. Radiological hazards associated with the sediments were determined by radiological parameters. The computed radiological parameters are above the recommended limits. Contour maps were generated using the kriging method and showed the spatial distributions for radionuclides. The activity concentrations exhibited in the order of 232Th > 40K > 238U using a box-whisker plot. Multivariate statistical methods are applied to determine relationships among the radionuclides and radiological hazard parameters. Future research could effectively address the issue of the possible impact of natural radiation on inhabiting this HBRA.