Buch Andressa Cristhy, Niemeyer Júlia Carina, Marques Eduardo Duarte, Silva-Filho Emmanoel Vieira
Postgraduate Environmental Geochemistry Program, Fluminense Federal University, Outeiro São João Baptista, s/n., Centro, 24020-141, Niterói, RJ, Brazil.
Postgraduate Program in Agricultural and Natural Ecosystems, Federal University of Santa Catarina (UFSC), Center of Curitibanos, Rod. Ulysses Gabordi, Km 3, 89520-000, Curitibanos, SC, Brazil.
J Hazard Mater. 2021 Feb 5;403:123852. doi: 10.1016/j.jhazmat.2020.123852. Epub 2020 Sep 14.
Environmental impacts caused by mine dam ruptures or inappropriate tailing depositions represent a global concern. An ecological risk assessment was performed in 18 areas affected by the collapse of a major mining dam in southeastern Brazil, in two monitoring periods (2015 and 2018). In these areas, pedogeochemical surveys, and ecological risk levels were determinate. In addition, ecotoxicological assays with Proisotoma minuta (Collembola) were carried out in laboratory. Soil screening values indicated that all contaminated areas were above regional reference values for soil quality for at least one metal (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn), likewise exceeding threshold values for potential ecological and human health risks. In two monitoring years, significant ecotoxicity in the avoidance and reproduction of P. minuta (> 60 % and >80 %, respectively) were evidenced in most soils; and lethal responses in some areas like Córrego Novo, Governador Valadares and Tumiritinga. Results suggest changes in soil physical-chemical properties due to tailing deposition, thus affecting soil dwellers. This study can elucidate the use of appropriate tools to ecological risk assessments, helping to identify the priority areas for defining remediation and monitoring strategies.
矿坝破裂或尾矿不当排放所造成的环境影响是一个全球关注的问题。在巴西东南部一座大型矿坝坍塌影响的18个区域，于两个监测期（2015年和2018年）进行了生态风险评估。在这些区域，开展了土壤地球化学调查并确定了生态风险水平。此外，在实验室中用微小原等节跳虫（弹尾目）进行了生态毒理学测定。土壤筛选值表明，所有受污染区域至少有一种金属（砷、镉、铬、铜、汞、镍、铅和锌）超过了土壤质量的区域参考值，同样也超过了潜在生态和人类健康风险的阈值。在两个监测年份中，大多数土壤中都证明微小原等节跳虫的回避和繁殖出现了显著的生态毒性（分别>60%和>80%）；在新科雷戈、瓦拉达雷斯州长市和图米里廷加等一些地区出现了致死反应。结果表明尾矿排放导致土壤理化性质发生变化，从而影响土壤生物。本研究可以阐明在生态风险评估中使用适当工具的情况，有助于确定定义修复和监测策略的优先区域。
