Determination of natural radionuclides and radioactive minerals in urban coastal zone of South India using Geospatial approach

The present study aims to investigate the geospatial variations in natural radioactivity, radiological risks, and the heavy mineral content along the urban costal zone of Chennai, South India. During the period of March 2019, ambient gamma radioactivity was measured proposed site using a Ludlum Model 19 micro-R survey meter and gamma-ray spectrometry using a Gamma-ray spectrometer with NaI (Tl) detector. The ambient gamma radiation levels at 13 urban beaches in Chennai megacity along the Bay of Bengal range from 18 to 965 nGy/h, with an average of 148 nGy/h. The natural radionuclides contributed to the effective dose in the order of ⁴⁰K > ²³²Th > ²³⁸U. The radionuclide activity concentration values confirmed that the sediments belong to the fluvial sources of beach placer or heavy minerals in the study area. (author)