Jialing River is one of the largest tributaries of the Yangtze River and the tributary with the most extensive drainage area among all the tributaries. In recent years, it has suffered severe heavy metal pollution. To study the spatial distribution, sediment fractions, sources and risks posed by Cd, Hg, Cu, Pb and Zn downstream of the Jialing River, 10 sampling sites were selected along the river, we collected surface sediments (0–5 cm), and we measured total concentrations of these five typical heavy metals. The results showed that in the study region, heavy metal pollution was more serious in the downstream areas than in the upstream region. Cd and Hg were found to be the most serious pollutants in the study region, at 2- to fivefold and 2- to fourfold higher than background values, respectively. We found significant correlations between the individual metals, indicating that their sources were similar. A high correlation coefficient was observed between sediments and riverbank soils, indicating that heavy metal accumulation in sediments was primarily the result of erosion. Potential ecological risk assessment ranked the severity of pollution for these metals as Cd > Hg > Cu > Pb > Zn. The average contribution rates of Cd and Hg were 49.42% and 43.41%, respectively, with 40% of the sites reaching a considerable ecological risk level. The concentrations of Cd, Zn and Pb present in the exchangeable (F1) and reducing (F2) fraction were > 50% of total concentration. This finding indicated a strong potential for release into the aquatic ecosystem. Special attention should be paid attention to discharges of Cd and Hg, and strategies should be developed to prevent further Cd and Hg pollution in the downstream reaches of the Jialing River.

嘉陵江是长江最大的支流之一，是所有支流中流域最广的支流。近年来，它遭受了严重的重金属污染。为了研究嘉陵江下游的Cd，Hg，Cu，Pb和Zn的空间分布，沉积物成分，来源和风险，沿河选择了10个采样点，我们收集了地表沉积物（0-5 cm），并且我们测量了这五种典型重金属的总浓度。结果表明，在研究区域中，下游地区的重金属污染比上游地区严重。发现镉和汞是研究区域中最严重的污染物，分别比背景值高2至5倍和2至4倍。我们发现各个金属之间存在显着相关性，表明它们的来源相似。在沉积物和河岸土壤之间观察到较高的相关系数，表明沉积物中重金属的积累主要是侵蚀的结果。潜在的生态风险评估将这些金属的污染严重程度排序为Cd> Hg> Cu> Pb> Zn。镉和汞的平均贡献率分别为49.42％和43.41％，其中40％的地点达到了相当大的生态风险水平。可交换的（F1）和还原的（F2）馏分中Cd，Zn和Pb的浓度大于总浓度的50％。这一发现表明了释放到水生生态系统中的强大潜力。应特别注意镉和汞的排放，