Rare earth elements as tracers of iron ore tailings on the Brazilian eastern continental shelf: Fid-Bau Portal

Rare earth elements as tracers of iron ore tailings on the Brazilian eastern continental shelf

Cagnin, Renata C. / Costa, Eduardo S. / Longhini, Cybelle M. / da Silva, Cesar A. / Sá, Fabian / Neto, Renato R.

AbstractIron ore tailings are stored in large dams and pose risks to the environment around the world. In Brazil, the rupture of these dams has become frequent and has generated environmental and social concern. Rare earth elements are good tracers of sediment sources and our results indicated chronic contamination of the seabed sediment from the marine region affected by the Fundão Dam tailings since 2015, including areas of environmental protection. This research, carried out between November 2018 and September 2021, with a database of 575 samples, showed a greater amount of contaminated material in the marine region adjacent to the Doce River mouth. Although data suggest prior mining contamination of the Doce River basin, the Fundão episode was an empirical and massive example of the environmental damage caused by these human activities over the centuries, showing that the impact remains in the shallow marine environments for years. Integr Environ Assess Manag 2024;20:179–188. © 2023 SETAC

ResumoOs rejeitos de minério de ferro são armazenados em grandes barragens que trazem riscos ao meio ambiente em todo o mundo. No Brasil, o rompimento dessas barragens tem se tornado frequente e gerado preocupação ambiental e social. Elementos terras raras são bons marcadores de fontes sedimentares e nossos resultados indicaram uma contaminação crônica da região marinha afetada pelos rejeitos da barragem de Fundão, incluindo áreas de proteção ambiental. Esta pesquisa teve com 575 amostras analisadas entre os meses de novembro de 2018 e outubro de 2021, com a região marinha adjacente a foz do Rio Doce apresentando o maior grau de impacto. Embora os dados ressaltem a contaminação histórica da mineração na bacia do Rio Doce, o episódio do Fundão foi um exemplo empírico e massivo dos danos ambientais causados por essas atividades ao longo dos séculos, mostrando que o impacto permanece nos ambientes marinhos rasos por anos. Integr Environ Assess Manag 2024;20:179–188. © 2023 SETAC

Key Points Rare earth elements are good tracers of sediment sources and our results indicated chronic contamination of the seabed sediment from the marine region affected by the Fundão Dam tailings since 2015, including areas of environmental protection. Although data suggest prior mining contamination of the Doce River basin, the Fundão episode was an empirical and massive example of the environmental damage caused by these human activities over the centuries, showing that the impact remains in the shallow marine environments for years.