Natural activities of [formula omitted], [formula omitted] and [formula omitted] in some Indian building materials

Abstract

The activity concentrations of 226 Ra , 232 Th and 40 K have been determined by gamma-ray spectrometry. The measured activity in the selected building materials ranges from (3.2 to 151.7 Bq/kg ), 14 to 63.7 Bq/kg and 24.3 to 121.5 Bq/kg for 226 Ra , 232 Th and 40 K respectively. The activity concentration of 238 U has been determined using fission track technique and the value ranges from 0.11 to 3.85 ppm . The concentrations for these natural radionuclides are compared with the reported data from other countries. Radium-equivalent activities (Ra eq) are calculated for the measured samples to assess the radiation hazards arising due to the use of these materials in the construction of dwellings. All building materials have shown Ra eq activities lower than the limit set in the Organization for Economic Cooperation and Development (OECD) report (370 Bq/kg) , equivalent to external gamma dose of 1.5 mSv yr −1 . A good correlation has been observed between 238 U and 226 Ra in these materials.