Human Health Risk Assessment of Physicochemical and Selected Trace Metal Contents of Borehole Water from Zebediela Sub-Region, Limpopo Province, South Africa

Abstract

Access to safe drinking water remains a critical public health concern, particularly in rural communities. This study assessed borehole water quality from eight villages in Zebediela sub-region, Limpopo Province, South Africa. Twenty (20) borehole samples were collected and analyzed for physicochemical parameters (temperature, pH, total dissolved solids, electrical conductivity, dissolved oxygen, and salinity) and the concentration of selected trace metals (Boron, Magnesium, Iron, Copper, Manganese, Selenium and Molybdenum). The physicochemical water quality of some areas exceeded the WHO regulatory guidelines and trace metals such as Mn, Se Mo, Cu and Mg exceeded the threshold limit associated with aesthetic and long-term health exposure. Multivariate statistical analysis revealed that the hydrochemical parameters were enriched by natural geochemical processes including ion exchange, dissolution of silicate minerals from limestone and agricultural activities. The health risk assessment revealed that non-carcinogenic risks were higher for children than for adults, with long-term cumulative exposure identified as the key contributor to these risks. Se and Mo were the major contributors to non-carcinogenic risks in both age groups. Therefore, targeted monitoring and management of Se and Mo concentrations in groundwater are strongly recommended to reduce potential public health impacts.

Keywords: Borehole water, trace metals, physico-chemical properties, health risk assessment, Zebediela.