Radionuclide and heavy metal contamination of drinking water sources in the Wonderfonteinspruit catchment, South Africa
The Wonderfonteinspruit (WFS) catchment is home to thousands of people, amongst them a significant number of informal settlement inhabitants, which largely rely on the Wonderfonteinspruit for domestic consumption on a daily basis or during water scarce periods. This research was aimed at: establishing the water sources and uses, the water quality and consequently the health risks arising from consumption of the water. Another aim was to investigate the challenges associated with accessing potable drinking water, and the effectiveness of the implementation of the water institution in South Africa with special reference to this catchment. Using questionnaires administered to communities, mines and the municipalities, data was gathered on the drinking water sources, from which water samples were collected and analyzed for heavy metals (As, Cd, Pb, Zn, Cd) and radionuclides (U isotopes) using inductively coupled plasma mass spectrometry (ICPMS) in the dry and wet seasons. In addition, the radiological absorbed dose and risk quotients for the various contaminants were computed using the contaminant concentrations. Research in the area has shown that there are radionuclides and heavy metals trapped in sediments of the Wonderfonteinspruit River. The findings revealed that there is significant usage of river water from the WFS for domestic consumption, either as an alternative or a main water source especially in the informal settlements. The quality of water from this river is not in compliance with the SANS 241 and WHO 2011 drinking water standards for As and U, thus statistically significant associations were observed between the concentrations of these contaminants in water and the occurrence of skin lesions and kidney inflammation respectively. As such, informal settlements of Carletonville, Bekkersdal and Khutsong are at potential risk of serious health problems as a result of their usage of the WFS for domestic consumption. A review of contemporary literature and government publications revealed that the poor implementation of the water institution could be attributed to non-collaboration between the various stakeholders. This study developed useful indices which can be used to measure community perception and a model for integrated waste and water resources management. Findings from this study are thus pertinent as they provide a baseline from which further epidemiological studies can be undertaken. Furthermore, these findings also have serious policy implications and could then be used in advancing water resources management in South Africa.