Toxic element enrichment and potential ecological risks from asbestos-bearing mine wastes

In developing countries, such as those in Africa, the existence of empirical data characterising the chemical composition and ecological and health risks of solid mine wastes, such as asbestos, is extremely limited. While the geological properties and carcinogenic risks of asbestos fibres have been long-known and well-researched, the potential ecological impacts of exposed asbestos mine wastes and asbestos-bearing geological deposits have largely been ignored. In this study a preliminary assessment of heavy metal pollution from asbestos-mine wastes is presented using different pollution indices in the context of source contamination. The quantitative contamination indices (enrichment factor, geo-accumulation index (I geo ), contamination factor (C f ), degree of contamination (C degree ) and pollution load index (PLI)), ecological risks and hazards quotient (HQ) were determined for chrysotile, amosite, crocidolite and anthophyllite mine waste types. The results indicate that the asbestos mine wastes contain high concentrations of heavy metals, greater than their respective background levels, with significant implications for ecological and human health risks.