Radioactivity in coral skeletons and marine sediments collected from the St. Martin's Island of Bangladesh

Although the coral island 'St. Martin's' serves as the most attractive place for leisure and tourism, but no data on radioactivity in coral skeleton is reported elsewhere. The mean activity concentrations (Bq/kg) for natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the sediment and coral reefs collected from the coastal waters of the Island were found to be 30.7 ± 2.1, 36.8 ± 2.8 and 388 ± 30, and 16.5 ± 1.3, 28.7 ± 1.9 and 334 ± 26, respectively; all lie within the respective world average values of 35, 35 and 450 Bq/kg except ²³²Th in sediment sample. Thus, the environment of coral reefs ecosystem of St. Martin's Island pose an insignificant radiological threats to the local dwellers and tourists.