Abstract:
Historical mine wastelands resulting from historical gold and uranium mining are lasting legacies of mining, leaving environmental degradation and social challenges for nearby communities. This study assessed the environmental impacts, community perceptions and management challenges associated with the historical mine wastelands in Brakpan (Kwa-Thema), South Africa, while also identifying appropriate management strategies. An interdisciplinary approach was used to combine community perception surveys, erosion modelling, and water and soil quality laboratory analysis to assess post-mining environmental and community risks.
The community survey involved structured questionnaires administered to purposively identify 90 residents residing in close proximity to the mine wasteland investigated. Respondents of over 18 years of age and various occupations reported health concerns such as respiratory ailments, dust exposure and contaminated water, especially among children. These concerns were supported by qualitative feedback, where nearly half (48%) of the respondents demanded urgent government-led rehabilitation, expressing dissatisfaction with current interventions and a lack of accountability.
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) results on heavy metals revealed elevated concentrations of uranium (U: 10.731 mg/kg), Chromium (Cr: 156.802 mg/kg) and Nickel (Ni: 129.081 mg/kg) in soil samples collected from mine tailings and exposed surfaces within the Brakpan (Kwa-Thema) mine wastelands, exceeding commonly referenced soil quality guidelines values (U: 1.400 mg/kg, Cr: 6.500 mg/kg, and Ni: 50.000 mg/kg). Surface water samples collected from nearby stagnant ponds and drainage pathways within the same area showed metal concentrations exceeding the South African National Standards for Drinking Water Quality and WHO guidelines (U: 0.030 mg/L, Cr: 0.050 mg/L, and Ni: 0.070 mg/L).
Gamma spectrometry confirmed high uranium-238 decay activity, while thorium-232 levels were lower and its decay progenies were recorded. Radiological hazard indices, including Annual Effective Dose (AED: 1.414 mSv/y) and Excess Life Cancer Risk (ELCR: 0.99×10⁻⁴), with AED surpassing regulatory limits of the National Nuclear Regulator and International Commission of Radiological Protection, indicate significant long-term radiological health risks to exposed populations. RUSLE modelling estimated soil loss at 75.281 tons/ha/year, with erosion hotspots observed within mine wasteland, particularly on loosely compacted tailings and exposed slopes. On-site inspections carried out during field visits assisted in identifying observable human activities, such as illegal dumping and evidence of unregulated past mining operations, which contributed to the environmental conditions observed in the study area.
Findings highlight ongoing environmental and health risks from inadequate rehabilitation and weak regulation. The study recommends erosion control, phytoremediation interventions, targeted health campaigns and stronger enforcement of the “polluter pays” principle. This study provides practical insights into the impacts and rehabilitation of mine wastelands in Brakpan, offering broader relevance for managing post-mining landscapes across South Africa and other regions of the Global South facing similar challenges.
