Laboratory of Environmental Geochemistry and Marine Pollution, Department of Oceanography, Center of Human and Natural Sciences, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil.
Laboratory of Marine Biogeochemistry, Department of Oceanography and Limnology, Center of Biosciences, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
Integr Environ Assess Manag. 2024 Jan;20(1):159-168. doi: 10.1002/ieam.4807. Epub 2023 Aug 2.
The coast of Espírito Santo state (Southeast Brazil) is recognized for its environmental arsenic (As) enrichment and, over the years, mining operations have potentialized it. We aimed to evaluate the effect of Rio Doce discharge on As inputs and the role of iron ore tailings from the Fundão dam disaster in enhancing As contamination in the marine sediment. Two scenarios were evaluated: Predisaster and Postdisaster; dry and wet conditions were considered in each period. High As concentrations were found in the Predisaster (28.44 ± 13.53 µg g ), but a significant increase in As was remarkable during the Postdisaster in the wet season, one year after the disaster (maximum of 58.39 µg g ; geoaccumulation index (I ) Class 3, moderately severe pollution). On that occasion, iron (Fe) oxy-hydroxides from tailings were remobilized from the Rio Doce channel and deposited on the continental shelf bottom. Therefore, chemical interactions among Fe, As, and carbonates were enhanced, resulting in As and Fe coprecipitation and the trapping by carbonate adsorption. Rio Doce discharge seems to be the main factor in As inputs to the inner continental shelf when flooding do not occur previously in samplings, which allows further dispersion of contaminants, although this hypothesis should be tested further. Integr Environ Assess Manag 2024;20:159-168. © 2023 SETAC.
巴西东南部圣埃斯皮里图州（Espírito Santo state）的海岸线以其环境砷（As）富集而闻名，多年来，采矿作业使其进一步恶化。我们旨在评估里约杜西（Rio Doce）河排放对砷输入的影响，以及丰当（Fundão）大坝灾难中铁矿石尾矿在增强海洋沉积物砷污染中的作用。评估了两种情景：灾难前（Predisaster）和灾难后（Postdisaster）；每个时期都考虑了干燥和潮湿条件。在 Predisaster（28.44 ± 13.53 μg g ）中发现了高浓度的砷，但在灾难后一年的潮湿季节中，As 的含量显著增加（最大值为 58.39 μg g ；地质累积指数（I ）为 3 级，中度严重污染）。在这种情况下，丰当尾矿中的铁（Fe）氢氧化物从里约杜西（Rio Doce）河道中重新迁移，并沉积在大陆架底部。因此，铁、砷和碳酸盐之间的化学相互作用增强，导致砷和铁共沉淀，并被碳酸盐吸附捕获。当洪水在采样前没有发生时，里约杜西（Rio Doce）河排放似乎是内大陆架砷输入的主要因素，尽管这一假设应该进一步检验，但这允许了污染物的进一步扩散。综合环境评估与管理 2024；20：159-168。2023 年 SETAC 版权所有。
