Ecological disaster in the making: Assessing the impact of Sino-Metals Leach tailings dam collapse on the Kafue River ecosystem

Abstract

• Toxic mine spillage in Zambia's Kafue River: heavy metals exceed safe limits. • Acidification and metal contamination threaten aquatic life and ecosystem. • Sediments amplify pollution, increasing ecological risk. • Human health and livelihoods at risk due to ecosystem collapse. • Immediate action needed to mitigate long-term damage. The Kafue River ecosystem in Zambia was contaminated following the Sino-Metals Leach Zambia Limited tailings dam collapse on February 18, 2025. This study assessed the spillage's effects on water quality, heavy metal concentrations, and bioaccumulation in fish and pasture samples. Water samples showed altered pH, electrical conductivity, turbidity, and salinity, with elevated Cu, Fe, Zn, Pb, and As levels exceeding ZEMA limits and international thresholds. Sediment analysis revealed substantial contamination, with heavy metal levels exceeding those in the control site. Similar bioaccumulation patterns were observed in fish and pasture samples, suggesting widespread ecosystem contamination. The findings indicate devastating effects, with altered water quality, including severely low pH levels, high heavy metal concentrations, and bioaccumulation creating a toxic environment likely contributing to the observed widespread loss of aquatic life. The bioaccumulation and potential biomagnification of these elements pose health risks to wildlife and humans, highlighting the urgent need for effective remediation strategies. This study provides the first comprehensive assessment of the Sino-Metals Leach tailings dam collapse's impact on the Kafue River ecosystem, integrating water quality parameters, heavy metal concentrations, and bioaccumulation in fish and pasture samples, offering a holistic understanding of the disaster's ecological footprint. Effective action is necessary to restore the ecosystem and ensure the long-term health and sustainability of the Kafue River.