Department of Soil Science and Agricultural Engineering, Federal University of Paraná, Paraná, Curitiba, Brazil.
Institute of Technology and Development (LACTEC), Curitiba, Paraná, Brazil.
Integr Environ Assess Manag. 2024 Jan;20(1):117-132. doi: 10.1002/ieam.4780. Epub 2023 May 26.
Previous studies of the Doce River basin (Brazil) seem to be contradictory regarding the contamination of soils with potentially harmful elements (PHE). This research aimed to perform an integrated assessment of PHE in the soil-plant-tailing system from the area most affected by the iron waste after the Fundão Dam disaster in 2015. Different fractions of PHE (exchangeable, nonexchangeable, reducible, and pseudo-total) were determined on deposited iron waste (DIW), soil waste mixture (SWM), and control soil (CS) samples. Total contents of PHE in Poaceae were also determined, and Allium cepa bioassays were performed to determine DIW and CS cytotoxicity and/or genotoxicity to plants. The Fe and Mn contaminations were the only ones related to the deposition of DIW on floodplains, and other harmful element content (such as As, Hg, Ni, Cd, Cr, and Pb) was not found above baseline values for soils. In addition, a significant part of the Fe and Mn in DIW is readily available or subject to acidification and prolonged flood reduction processes. The high available content of Fe favored its excessive accumulation by Brachiaria. The DIW chemical conditions reduced biological functions of A. cepa under a controlled environment. However, more drastic effects, such as genetic damage, were not seen. The postdisaster action of covering DIW with CS resulted in undesirable enrichment of Pb on the floodplain soils. The integrated results allow the conclusion that the iron waste is not a time bomb for PHE contamination of soils between the Fundão and Risoleta Neves Hydroelectric Dam (~100 km away from Fundão). Integr Environ Assess Manag 2024;20:117-132. © 2023 SETAC.
先前对多塞河盆地（巴西）的研究似乎对土壤中潜在有害元素（PHE）的污染存在矛盾。本研究旨在对 2015 年丰当大坝灾难后受铁废料影响最严重的地区的土壤-植物-尾矿系统中的 PHE 进行综合评估。在沉积铁废料（DIW）、土壤废料混合物（SWM）和对照土壤（CS）样品上测定了 PHE 的不同形态（可交换态、不可交换态、可还原态和总量）。还测定了 Poaceae 中的总 PHE 含量，并进行了洋葱生物测定，以确定 DIW 和 CS 对植物的细胞毒性和/或遗传毒性。Fe 和 Mn 的污染与 DIW 在冲积平原上的沉积有关，而其他有害元素（如 As、Hg、Ni、Cd、Cr 和 Pb）的含量并未超过土壤的基线值。此外，DIW 中很大一部分 Fe 和 Mn 是易于获得的，或易受酸化和延长洪水减少过程的影响。Fe 的高可用性含量有利于 Brachiaria 的过度积累。DIW 的化学条件降低了 A. cepa 在受控环境下的生物功能。然而，并没有看到更严重的影响，如遗传损伤。用 CS 覆盖 DIW 的灾后行动导致洪水泛滥平原土壤中 Pb 的富集。综合结果表明，丰当和里索莱塔内韦斯水电站（距离丰当约 100 公里）之间的铁废料不是土壤中 PHE 污染的定时炸弹。综合环境评估与管理 2024;20:117-132. © 2023 SETAC。
