An ecotoxicological assessment of mine tailings from three Norwegian mines

Abstract

The study assessed the environmental toxicity of three Norwegian mine tailings from Omya Hustadmarmor, Sydvaranger, and Sibelco, which are all released into a seawater recipient. Ecotoxicity assessments were performed on the overlying water extracted from the mine tailings, the transformation/dissolution waters obtained from the mine tailings, and whole sediment assessment using a suite of marine organisms including algae, Crustacea, and Mollusca. Overall, based on the toxicity evaluation of the transformation/dissolution data, Sibelco tailings resulted in the highest toxicity albeit at relatively high concentrations, followed by Sydvaranger and Hustadmarmor. Sibelco was the only mine where process chemicals were not used. In contrast, the Corophium sediment contact assay revealed a significantly higher toxicity exerted by Hustadmarmor tailings, which may indicate a physical impact of the fine tailings. The effects observed were discussed with respect to both the measured chemical concentrations of the tailings and the potential physical impact of the tailing particles on organism health.

Keywords: Bioassays; Dissolution; Mine tailings; Sediment contact assay; Transformation.