Abstract
A hyper-pure germanium (HPGe) detector was used to measure the activity concentrations in sediment samples of rivers in South Africa, and the associated radiological hazard indices were evaluated. The results of the study indicated that the mean activity concentrations of 226Ra, 232Th and 40K in the sediment samples from the oil-rich areas are 11.13, 7.57, 22.5 ; 5.51, 4.62, 125.02
and 7.60, 5.32, 24.12
for the Bree, Klein-Brak and Bakens Rivers, respectively. In contrast, the control site (UMngeni River) values were 4.13, 3.28, and 13.04
for 226Ra, 232Th, and 40K. The average excess lifetime cancer risks are 0.394 ×
, 0.393 ×
, 0.277 ×
and 0.163 ×
for sediment samples at Bree, Klein-Brak, Bakens, and uMngeni rivers. All obtained values indicated a significant difference between the natural radionuclide concentrations in the samples from the rivers in oil-rich areas compared to those of the non-oil-rich area. The values reported for the activity concentrations and radiological hazard indices were below the average world values; hence, the risk of radiation health hazard was negligible in all study areas.
ACKNOWLEDGEMENTS
The authors are grateful to iThemba LABS, Capetown, South Africa, most notably Dr Peane Maleka and Mistura B. Ajani, for giving us access to their Environmental Research Laboratory (ERL) to measure the radioactivity levels in the samples. They were supportive during the analysis of the samples. Acknowledgements are also extended to the research farm's technical staff and the School of Life Sciences, University of KwaZulu–Natal Pietermaritzburg campus, for their professional contributions.
DISCLOSURE STATEMENT
No potential conflict of interest was reported by the author(s).