Application of multivariate technique to evaluate spatial distribution of natural radionuclides along Tamil Nadu coastline, east coast of India

Abstract

The study focuses on the spatial mapping of naturally occurring radionuclides along entire Tamil Nadu coast, which constitute nearly 30% of the east coast of India. In view of this, a total of 37 beach sediment samples are collected, and spectral measurement was carried out by High Purity Germanium detector. The average activity concentrations were found to be in the range of 34.33 ± 32.94 Bq kg−1 for 238U, 51.55 ± 40.39 Bq kg−1 for 238Th and 282.59 ± 84.45 Bq kg−1 for 40K. The contour maps showed the spatial distributions of each radionuclide and were drawn using the kriging method. Box-whisker plot shows the variation of activity concentrations of radionuclides, which follows the order 40K > 232Th > 238U in all the sediment samples. To understand the complex relationships among the radioactive variables and its environmental classifications, a multivariate statistical technique such as correlation matrices, and cluster analysis were applied to the radioactive data sets.