Natural radioactivity content in Adyar River estuary of Chennai city, India

Abstract Natural radioactivity content in beach sands covering equally on both sides of Adyar River estuary of Chennai city, India, has been determined using gamma-ray spectroscopy. The average activity content of 238 U, 232 Th, and 40 K in the sand samples is found to be 34.1 ± 6.5 Bq.kg −1 , 40.8 ± 4.6 Bq.kg −1 , and 356 ± 34.1 Bq.kg −1 , respectively. It is observed that 232 Th alone is higher than the UNSCEAR 2000 world average value of 45 Bq.kg −1 , around the mouth of Adyar River, but its levels drop as one moves either side, i.e., upstream or downstream. 238 U and 40 K are in general below the UNSCEAR 2000 world average value of 33 and 420 Bq.kg −1 , respectively. Radiological parameters such as absorbed dose rate, annual effective dose, and radium equivalent activity are calculated to provide a vivid picture of radiological status existing in the beach sands around the Adyar River estuary. The results of the present study indicate that the beach sand samples obtained from around Adyar River estuary do not have any radiation effect to the members of the public in the environment due to natural radioactivity content.