Mineralogical characterization and environmental radiation health assessment in brick samples of Tamil Nadu

Abstract

Natural radioactivity due to 238U, 232Th, and 40K in brick samples from Tamil Nadu was determined using gamma-ray spectrometry. The calculated mean activity concentrations of 238U, 232Th, and 40K, 69 ± 6, 62 ± 6, and 462 ± 23 Bq kg− 1, are higher than the world recommended limits of 35, 45, and 420 Bq kg− 1, respectively, and they are compared with the other countries. The calculated radiological parameters radium equivalent activity (193 ± 17 Bq kg− 1), internal hazard index (0.71 ± 0.06), activity utilization index (1.43 ± 0.13) were lower, while absorbed dose rate (89 ± 8 nGy h− 1), annual effective dose equivalent (0.43 ± 0.04 mSv y− 1) and excess lifetime cancer risk (1.52 ± 0.13 mSv y− 1), which are slightly higher than the world’s recommended limits. The minerals presented in the soil samples were identified using FT-IR and XRD techniques. Both techniques revealed that the presence of quartz, orthoclase, kaolinite, microcline, albite, illite, calcite, montmorillonite and organic carbon in the samples. Bi-variate statistical analysis was estimated to corroborate the relationship between radionuclides and radiological hazards.