Origin, fate and ecotoxicity of manganese from legacy metallurgical wastes

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