Spatial Distribution and Radiological Risk Quantification of Natural Radioisotopes in the St. Martin’s Island, Bangladesh

Abstract

AbstractThe radioactivity concentrations of 226Ra, 232Th and 40K were measured by HPGe gamma-ray spectroscopy in beach sand and water samples collected from and around the only coral reefed Island (St. Martin’s), in the Bay of Bengal. Average activity concentrations of 226Ra, 232Th and 40K are 15.53, 15.42 and 372.32 Bq kg−1 for beach sand samples, and 4.96, 4.67 and 22.78 Bq kg−1 for water samples, respectively. No artificial radionuclides (e.g., 134Cs, 137Cs) were detected in any of the analyzed samples. Lower activity concentrations of sand samples compared to those of other coastal areas of the Bay of Bengal may be due to the thick coral reef of this island. The estimated radiation hazard parameters including radium equivalent activity, radiation hazard index, annual effective dose rate, absorbed dose rate and excess lifetime cancer risk are lower than the permissible limits. In terms of radiological parameters, this island is quite safe for tourism.KeywordsCoral reefed islandNaturally occurring radionuclidesBeach sand and waterRadiological hazard indicesSt. Martin’s IslandBangladesh