Are our beaches safe? Evaluating natural radioactivity ((238)U, (232)Th, and (40)K) and radiological hazards in selected beaches of India.

内容摘要

This study investigated the radiation footprints of primordial radioisotopes within sand deposits across the intertidal, berm, and dune zones of India's Blue Flag beaches located adjacent to granite-gneissic plutons, ophiolites, and the Deccan Plateau. The study aimed to establish a baseline data to contribute to the global natural radioactivity database. A gamma-ray spectrometer using a high-purity germanium (HPGe) detector with 100% relative efficiency was used to measure the radioactivity concentrations. The average primordial radionuclide activities in the beach sands ranged from 2.02 ± 0.17 to 9.55 ± 0.27 Bq kg-1 for 238U, 3.55 ± 0.26 to 26.33 ± 0.61 Bq kg-1 for 232Th, and 42.55 ± 1.50 to 353.68 ± 3.35 Bq kg-1 for 40K. The association and covariation among the radionuclides were studied using multivariate analysis to ascertain distribution pattern, possible common origins, and controlling factors. Ionizing radiation and associated environmental and human health hazards were assessed using various radioactivity indices-such as external hazard index, absorbed dose rates, annual effective dose equivalent, annual gonadal dose equivalent, gamma index, and excess lifetime cancer risk. The estimated values of radioactivity indices of the studied Blue Flag beaches were less than the global reference values established by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). This suggested that the exposure levels remained within the acceptable health safety margins for tourism and recreational activities.