Radiometric and health risk assessment of building materials collected from Tamil Nadu using gamma-ray spectrometry

Abstract

ABSTRACT The radiometric analysis was carried out on different building materials collected from Tamil Nadu, using gamma-ray spectroscopy with NaI(Tl) detector. The mean activity concentrations of 226Ra (38 Bq kg−1) and 40K (643 Bq kg−1) in all building materials were higher than the world-populated weighted average of 33 Bq kg−1 and 420 Bq kg−1, respectively, while for 232Th (28 Bq kg−1), it was lower than 45 Bq kg−1, as reported by UNSCEAR (2000). These results were compared with similar studies carried out around the world. The calculated radiological parameters, radium equivalent activity (127 ± 11 Bq kg−1), absorbed dose rate (61 ± 5 nGy h−1), annual effective dose equivalent (0.30 ± 0.02 mSv y−1), internal and external hazard index (0.45 ± 0.04 and 0.34 ± 0.03) and activity utilisation index (0.74 ± 0.08), are within the world-populated weighted average and safest limits. Moreover, the radiogenic heat production rate (RHP) due to the natural radionuclides in the building materials was calculated, and the total RHP was 0.94 µWm−3. Multivariate statistical analyses, such as Pearson correlation analysis, hierarchical cluster analysis and factor analysis, were implemented on activity concentration and radiological parameters to evaluate the interrelationship between them.