Origin, fate and ecotoxicity of manganese from legacy metallurgical wastes. (August 2021)

• Record Type: Journal Article
• Authors: Petitjean, Quentin; Choulet, Flavien; Walter-Simonnet, Anne-Véronique; Mariet, Anne-Lise; Laurent, Hervé; Rosenthal, Patrick; de Vaufleury, Annette; Gimbert, Frédéric
• Is Part Of: Chemosphere. Volume 277(2021)
• Publication Date: 2021-08
• Subjects: Slags -- Weathering -- Metals -- Chemical extraction -- Bioavailability -- Snails; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.130337
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Over the course of history, mining and metallurgical activities have influenced the socioeconomic development of human populations. However, these past and current activities can also lead to substantial environmental contamination by various metals. Here, we used an interdisciplinary approach (incorporating archaeology, mineralogy, environmental chemistry and ecotoxicology) to investigate the origin, fate and potential ecotoxicity of anomalous manganese (Mn) concentrations detected in the ancient mining district of Berthelange (medieval period, eastern France). Mineralogical investigations of slag samples showed that smelting temperature conditions in medieval bloomeries led to the production of slags mainly composed of Fe- and Mn-rich olivine, i.e ., fayalites. Further mineralogical analyses of bulk soil and clay fractions allowed us to identify the presence of serpentine. This evidence of olivine weathering can account for the release of Mn from slags into the soil. In addition, chemical analyses of total and available (exchangeable and reducible) Mn concentrations in soil samples clearly showed the contribution of slags deposited 1000 years ago to soil contamination. A complementary ecotoxicity bioassay performed on soils from a slag heap using the land snail Cantareus aspersus confirmed that a significant fraction of the Mn detected in soils remains available for partitioning with the soil solution and transfer to soil organisms. Although no growth inhibition of snails was observed after 28 days of exposure, the animals accumulated quite elevated Mn concentrations in their tissues. Our study emphasizes the environmental availability and bioavailability of Mn from ancient metallurgical wastes to soil-dwelling invertebrates, i.e ., snails, even one millennium after their deposition. Hence, as for more recent industrial sites, past mining ecosystems must be a cause of concern for the scientific community and public authorities. Graphical abstract: Image 1 Highlights: Slags from the 11th century contain high amounts of Mn mostly found in fayalite. Slag weathering over centuries has led to Mn release and soil contamination. Ecotoxicity tests using snails revealed the bioavailability of Mn in soils. Sites of past metallurgical activities remain a cause of environmental concern.