The Ilha River is one of the main tributaries of the Sinos River, southern Brazil, and it is located in an area characterized by low population density and presence of agricultural activities. Thus, this study aimed to assess the water quality of two sites of the Ilha River (source and mouth, S1 and S2 respectively) in five sampling periods using water physicochemical and microbiological analyses, biomarkers, such as condition factor, micronucleus test, gill histopathological analysis, and metal bioaccumulation in the native fish Bryconamericus iheringii. Mean values of BOD₅, thermotolerant coliforms, aluminum, iron and lead exceeded the limits established by the Brazilian legislation for surface waters at both sampling sites. Significant higher micronucleus, nuclear abnormalities and mucous cells frequencies were found at S2 in, at least, one sampling period, whereas fish from S1 presented significant lower condition factor, higher frequencies of lamellar alterations and higher concentrations of chromium and nickel in muscle. Additionally, concentrations of cadmium, chromium and lead in fish muscle exceeded the limits considered for safe human consumption at both sites in at least one sampling period. Data from our study evidenced the mouth of the Ilha River suffers from point genotoxic effects, whereas the source is also contaminated by metals, despite being located in an area under minor anthropic activities.

中文翻译：

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巴西南部伊利亚河捕获的本地鱼类的水质参数，生物标志物和金属生物富集

伊利亚河（Ilha River）是巴西南部西诺斯河（Siins River）的主要支流之一，它位于人口密度低和从事农业活动的地区。因此，本研究旨在利用水的理化和微生物学分析，诸如条件因子，微核试验，g组织病理学等生物标记物，在五个采样期内评估伊利亚河两个站点（分别为水源和河口，S1和S2）的水质。分析和本地鱼类Bryconamericus iheringii中的金属生物富集。BOD _5的平均值，耐热大肠菌，铝，铁和铅超过了巴西法律规定的两个采样点地表水的限量。至少在一个采样周期内，S2处发现了较高的微核，核异常和粘液细胞频率，而S1处的鱼呈现出显着较低的条件因子，较高的层状变化频率和较高的肌肉中铬和镍浓度。此外，鱼肉中镉，铬和铅的浓度在至少一个采样周期内都超过了人类在两个地点安全食用的极限。我们的研究数据表明，伊利亚河的河口遭受点遗传毒性影响，尽管其源头位于人类活动较少的地区，但其来源也被金属污染。