Chemical and Radiological Risks of Drinking Water from Communities in Wonderfonteinspruit Catchment, South Africa

Abstract

A health risk assessment was carried in the Wonderfonteinspruit catchment for the informal and formal settlements of three towns (Bekkersdal, Khutsong and Carletonville) located along the river. The aim of the study was to establish the quality of drinking water from the identified sources and determine the health risks associated using risk quotients and annual radiological absorbed dose. 12 sampling points were chosen to represent the identified drinking water sources, consisting of 6 formal and 6 informal water sources. Three water samples were collected per point and these were analyzed using ICP-MS for As, Cd, Co, Pb, Zn and U isotopes. Further calculations for risk quotients and radiological absorbed doses as well as statistical analysis were carried out using MS Excel and SPSS. Findings revealed that As and U (235 and 238) concentrations along the river were in excess of the WHO and SANS 241 (2011) guidelines, thus risk quotients in excess of 1 were recorded at various points. Statistical correlations were observed between the As concentrations and the occurrence of skin cancers as well as the U concentrations and the occurrence of kidney cancer. The annual radiological absorbed dose was within the prescribed range of 0.1msv/year for all the age groups. These findings present serious health repercussions for the informal settlements that rely on this water for domestic consumption. A gap in knowledge surrounding the synergistic mechanisms of these metals on health poses uncertainty and warrants a baseline epidemiological study in the catchment.