The objectives of this study were (i) to evaluate the quality of the Ouro River, a tropical Brazilian river, assessing the concentration of the metals in surface waters, sediments, and benthic macroinvertebrates; (ii) to investigate the possible sources of pollution in Ouro River basin through field research and spatial analysis (G.I.S.); (iii) to evaluate the possible occurrence of metals bioaccumulation in the trophic chain, by comparing the concentration of the metals in water, sediments (total and bioavailable) and in benthic macroinvertebrates; and (iv), to assess the biological metrics of benthic macroinvertebrates that inhabit the Ouro River, and the possible relation regarding its distribution (richness, abundance, dominance) with the human occupancy. Water, sediment, and macroinvertebrates samples were assessed in five sample sites for 9 months. The macroinvertebrates were arranged, identified, and analyzed taxonomically. The concentrations of Cu, Zn, Fe, Mn, Cd, Pb, and Cr in waters and sediments (total and Mehlich-1) were determined, the obtained results were compared to Brazilian and international standards indexes (Igeo and E.F.). According to our findings, the quality of Ouro River is directly affected by the human activities carried out in the watershed, and despite that the vast majority of the assessed metals in water was found below the legislation maximum levels, these accumulate in sediments, with extremely high enrichment of Cd, and moderately to heavily contamination of Cd, Mn, and Cu. Also, Zn and Pb high bioaccumulation in macroinvertebrates was observed, in which concentrations were 172% and 92% higher than the mean total concentration in sediment. The fit's goodness indicates that Mehlich-1 could be used as an extractant solution for the correlation of Pb in sediments and B.M.I. On average, Pb levels in the benthic are 14.94× higher than the bioavailable fraction in sediments (Mehlich-1). Mainly for Decapoda, Bivalve, and Gastropoda, results indicate high adsorption rates of Pb and Zn. The probable metal contamination in the Ouro River basin is from diffuse sources such as agriculture erosion (fertilizers and fertilizers with heavy and toxic heavy metals).

这项研究的目的是：（i）评估巴西的热带河流欧鲁河的质量，评估地表水，沉积物和底栖大型无脊椎动物中金属的浓度；（ii）通过野外研究和空间分析来调查欧鲁河流域可能的污染源；（iii）通过比较水，沉积物（全部和生物利用度）和底栖大型无脊椎动物中金属的浓度，来评估营养链中金属生物富集的可能发生；（iv）评估居住在欧鲁河底栖无脊椎动物的生物学指标，以及其分布（丰富度，丰度，优势度）与人类居住的可能关系。水，沉积物，在五个采样点对大无脊椎动物样品进行了为期9个月的评估。对大型无脊椎动物进行分类，鉴定和分类。测定了水和沉积物中铜，锌，铁，锰，镉，铅和铬的含量（总计和Mehlich-1），并将所得结果与巴西和国际标准指标（Igeo和EF）进行了比较。根据我们的调查结果，乌鲁河的水质直接受到流域中人类活动的影响，尽管水中的绝大多数被评估金属含量都低于法律规定的最高水平，但这些金属却沉积在沉积物中，其中极高的水平Cd富集度高，Cd，Mn和Cu污染程度中等至重度。此外，在大型无脊椎动物中还发现了Zn和Pb的高生物蓄积性，其浓度分别比沉积物的平均总浓度高172％和92％。拟合的良好性表明，Mehlich-1可用作提取物解决方案，用于沉积物中铅与BMI的相关性。平均而言，底栖动物中的Pb水平比沉积物中生物利用度（Mehlich-1）高14.94倍。主要用于十足目，双壳纲和腹足纲，结果表明Pb和Zn的高吸附率。欧鲁河流域可能的金属污染来自诸如农业侵蚀（含有重金属和有毒重金属的肥料和肥料）之类的扩散源。比沉积物中的生物利用度高94倍（Mehlich-1）。主要用于十足目，双壳纲和腹足纲，结果表明Pb和Zn的高吸附率。欧鲁河流域可能的金属污染来自诸如农业侵蚀（含有重金属和有毒重金属的肥料和肥料）之类的扩散源。比沉积物中的生物利用度高94倍（Mehlich-1）。主要用于十足目，双壳纲和腹足纲，结果表明Pb和Zn的高吸附率。欧鲁河流域可能的金属污染来自诸如农业侵蚀（含有重金属和有毒重金属的肥料和肥料）之类的扩散源。