Ecotoxicity of Mine Tailings: Unrehabilitated Versus Rehabilitated

• Published in: Bulletin of environmental contamination and toxicology Vol. 100; no. 5; pp. 702 - 707
• Main Authors: Maboeta, M. S., Oladipo, O. G., Botha, S. M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2018; Springer Nature B.V
• Subjects: Animals; Aquatic Pollution; Bioindicators; Biological Assay; Biomarkers; Biomass; Breeding success; Cadmium; Copper; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental Pollution - statistics & numerical data; Environmental Restoration and Remediation; Gold; Indicator species; Mining; Nickel; Oligochaeta - physiology; Pollution; Rehabilitation; Soil - chemistry; Soil Pollutants - analysis; Soil Pollutants - toxicity; Soil pollution; Soil Science & Conservation; South Africa; Tailings; Waste Water Technology; Water Management; Water Pollution Control; Post-mining restoration strategy; Biomarkers; Rehabilitated and unrehabilitated sites; Gold mine tailings; Soil pollution; Eisenia andrei
• ISSN: 0007-4861; 1432-0800
• DOI: 10.1007/s00128-018-2322-8

Earthworms are bioindicators of soil pollution. The ecotoxicity of tailings from selected gold mines in South Africa was investigated utilizing Eisenia andrei bioassays and biomarkers. Samples were obtained from unrehabilitated, rehabilitated and naturally vegetated sites. Biomass, neutral red retention time (NRRT), survival and reproduction were assessed using standardized protocols. Earthworm biomass, NRRT and reproductive success in rehabilitated tailings (comparable to naturally vegetated site) were significantly higher ( p  < 0.05) than in unrehabilitated tailings. In addition, significantly lower ( p  < 0.05) body tissue concentrations of As, Cd, Co, Cu and Ni contents were found in the rehabilitated tailings compared to the unrehabilitated. Further, significantly lower ( p  < 0.05) soil Mn and Zn concentrations were obtained in unrehabilitated tailings than the rehabilitated and naturally vegetated sites. Overall, reduced ecotoxicity effects were confirmed in rehabilitated compared to unrehabilitated tailings. This suggests that rehabilitation as a post-mining restorative strategy has strong positive influence on mine tailings.