Measurement of 226Ra, 232Th and 40K and the associated radiological hazards in Ponnai river sand, Tamilnadu, India using Gamma ray spectrometry

摘要

ABSTRACT River sand is a one of the important and commonly used building material in India and hence in the present study, activity concentration of natural radionuclides such as 226Ra, 232Th and 40?K have been measured in sand samples collected from Ponnai river, Tamilnadu using HPGe detector-based gamma ray spectroscopy. The measured activity concentrations vary from 13.30 to 54.83?Bq kg?1 with a mean value of 31.07?Bq kg?1 for 226Ra, from 26.15 to 245.33?Bq kg?1 with a mean value of 83.61?Bq kg?1 for 232Th, from 218.76 to 581.88?Bq kg?1 with a mean value of 416.36?Bq kg?1 for 40?K. These mean values of activity concentration of radionuclides have been compared with recommended limit and other similar work carried in the world. In order to assess the radiation associated with sands, radiological parameters such as air absorbed dose rate, annual indoor and outdoor effective dose rate, excess lifetime cancer risk, were calculated. The result shows that excess lifetime cancer risk (ELCR) for the indoor exposure varied from 0.775?×?10?3 to 3.216?×?10?3 with an average value of 1.440?×?10?3. An average ELCR for Ponnai river sand samples is slightly higher than the world average value of 1.16?×?10?3 mSv y?1. Finally, to assess the delivery of gamma radiation to organs, effective dose to body organ (Dorgn) was calculated for all river sand samples in the study area.