Natural radioactivity assessment in the sands from Tirunelveli District, Tamil Nadu, India

Abstract Natural sand, which is predominantly observed in river bottoms, is widely used in construction projects. In the current study, the NaI (Tl) gamma-ray spectrometer was employed to evaluate the natural radioactivity caused by the presence of 226 Ra, 232 Th, and 40 K in sand samples collected from the Tirunelveli district, Tamil Nadu, India. The concentrations of 226 Ra, 232 Th, and 40 K varied from ≤5.1 (minimum detectable activity [MDA]) to 33 ± 3 Bqkg −1 , ≤5.0 (MDA) to 329 ± 29 Bqkg −1 , and 392 ± 37–706 ± 69 Bqkg −1 for 226 Ra, 232 Th, and 40 K, respectively. A number of radiological hazard indices were evaluated, including the absorbed dose rate, radium equivalent activity (R eq ), indoor and outdoor annual effective dose (H R[In] and H R[Out] ), alpha index (I α ), and gamma index (I γ ). To interpret the findings, univariate statistical analyses were performed. The significance of environmental radiation monitoring for public safety is demonstrated by this study.