The radiological impacts of radioactivity in the Crown Mines gold tailings

Mining is the main source of environmental radioactivity in areas where nuclear weapons tests are not conducted. The dispersion of radioactivity in the form of dust is inevitable for residents living near mine tailings. There have been complaints in areas such as Riverlea, in Soweto, Johannesburg, about dust pollution causing skin irritations and severe respiratory problems. The area is very close to the gold mine tailings. Soil samples were randomly collected from the Crown Mines gold tailings and the abandoned mines located west of Johannesburg, behind Soccer City Stadium. The specific activity was assessed using coaxial HPGe γ-spectroscopy, which measured the γ-signals in the soil samples, and the comprehensive radiological indices were subsequently evaluated. The results showed that the mean activity concentrations in some samples exceeded the global average, particularly for radium. The average concentrations of Formula: see textRa, Formula: see textTh, and Formula: see textK were 302.99 ± 6.60, 8.25 ± 1.31, and 113.34 ± 20.80 Bq/kg, respectively. The average radiological indices exceeded their globally recommended values with the values of 1006.34 ± 22.10 Formula: see textSv/y for AGDE, 323.50 ± 7.04 Bq/kg for RaFormula: see text, 293.98 ± 6.40 nGy/h for ADR, 5.05 ± 0.11 Formula: see text for ELCR, 1.69 ± 0.05 for HFormula: see text, 1.44 ± 0.03 mSv/y for AEDE, 1.09 ± 0.04 for IFormula: see text and 1.51 ± 0.03 for IFormula: see text. Statistical analyses, including skewness, kurtosis, Pearson correlation coefficients, and ANOVA, were used to characterise radionuclide distributions and relationships. The Pearson correlation matrix revealed a strong positive correlation between Formula: see textRa and all estimated radiological hazard indices, while Formula: see textTh and Formula: see textK showed a weak but positive correlation with Formula: see textRa and all indices. These findings suggest that radioactivity from the ambient geology of the mining tailings under survey poses a serious health risk, even if the impacts are not immediate. Therefore, close monitoring and evaluation of these tailings are necessary to ensure that residents' exposure remains as low as reasonably achievable. These are significant indicators of potential harm to human health, wildlife, and ecosystems, as ionising radiation can damage living cells and genetic material, specifically DNA.