The decline in the quality of water resources in the Amazon is very rapid in cities suffering from unplanned urban growth. The region has two defined seasons, winter (wet) and summer (dry), which directly affect the behavior of contaminants in aquatic ecosystems. The aim of this study was to assess the ecological and human health risks associated with the use of the watershed. In addition, an ecological index was proposed: the Quality Index for Aquatic Life, for the risk of contaminants to aquatic life. Sampling was carried out at six points in the Juá watershed. Physicochemical parameters, major anions, metals and total phosphorus were analyzed at both stations between 2020 and 2021. The highest concentrations of contaminants were found in the rainy season, due to the washing away of the banks. In this sense, Cl presented a concentration more than 307 times higher than that permitted by Brazilian legislation (wet). The ecological index showed that the watershed has a high risk of metals such as Cr III and Cr VI for the biota. The human health risk analysis showed a low risk; however, the lack of basic sanitation in the city indicates that monitoring of urban water resources is necessary.

在遭受无计划城市增长的城市中，亚马逊河流域的水资源质量下降得非常快。该地区有两个明确的季节，冬季（潮湿）和夏季（干燥），直接影响水生生态系统中污染物的行为。本研究的目的是评估与流域的使用相关的生态和人类健康风险。此外，还提出了一个生态指数：水生生物质量指数，用于衡量水生生物污染物的风险。在 Juá 流域的六个点进行了采样。 2020 年至 2021 年间，对两个监测站的理化参数、主要阴离子、金属和总磷进行了分析。由于河岸被冲走，在雨季发现污染物浓度最高。从这个意义上说，Cl 的浓度比巴西立法允许的浓度（湿）高出 307 倍以上。生态指数显示，该流域对生物群具有较高的Cr III、Cr VI等金属风险。人体健康风险分析显示风险较低；然而，城市缺乏基本的卫生设施表明有必要对城市水资源进行监测。