Assessment of natural and fallout radioactivity in soil samples of Visakhapatnam

Environmental gamma radiation levels around the new Bhabha Atomic Research Centre site at Visakhapatnam have been assessed. Natural and anthropogenic radionuclide activity concentrations in soil samples collected were determined using high-resolution gamma spectroscopy. Average activity concentrations of 238U, 226Ra, 232Th and 40K were found to be 38, 38, 230 and 520 Bq kg-1, respectively. No anthropogenic radionuclide except fallout 137Cs having mean concentration range ≤ 0.2-2.2 Bq kg-1 was detected in the soil samples. The observed values are compared with the values reported for different areas in India and other parts of the world. The annual total external gamma radiation dose to the members of public estimated using the above observations ranged from 0.13 to 0.38 mSv y-1 with an average of 0.25 mSv y-1. (author)