## 5 Conclusions  
A systematic analysis was conducted to investigate the spatial distribution characteristics, pollution sources, and health risks associated with HMs in sediments of the YRB. The results show that As, Zn, and Cd are the main elements causing HM pollution in sediments of the YRB, and the pollution levels of the studied HMs in the sediments are mostly \"low to moderate\". Source apportionment results demonstrated that HM contamination originated from three principal pathways: traffic-industrial sources (32.47%), agricultural-industrial sources (44.87%), and industrial emissions (22.66%). The clarification of the spatial distribution, main sources, and human health risk assessment of HMs indicates that As and Zn are the priority elements for human health risk control, and agricultural-industrial sources are the priority sources for pollution prevention and control.  
Given that the concentrations and sources of HMs in sediments of the YRB may be influenced by a variety of factors, it is recommended that long-term, site-specific monitoring studies be conducted across the entire basin in the future. Through monitoring data accumulated over several years, it will be possible to more accurately assess the dynamic trends in HM concentrations and their sources and to reveal their long-term interactions with human activities and climate change within the basin. In addition, current research has mainly focused on the characteristics of HM concentrations in sediments. In the future, the scope of research can be further expanded to conduct comprehensive studies of HMs in multiple media, such as water, soil, and biota. By analyzing the concentrations, speciation, and transformation relationships of HMs in different media, a comprehensive assessment system for HM pollution at the basin scale can be established.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15095188/sl](https://www.mdpi.com/article/10.3390/app15095188/sl)]([https://www.mdpi.com/article/10.3390/app15095188/sl](https://www.mdpi.com/article/10.3390/app15095188/sl)), Figure S1: Non-carcinogenic risk and total carcinogenic risk probability of HMs in the sediments of the Yellow River. Table S1: Parameter values of health risk assessment model in sediments via Monte Carlo simulation. Table S2: Slope factor and reference dose of HMs. Table S3: HM content in sediments. Table S4: Average non-carcinogenic and carcinogenic risks of HMs in sediments via different exposure pathways.  
Conceptualization, K.F. and G.X.; methodology, K.F. and X.C.; software, G.X. and Y.W.; validation, K.F., J.L., Y.W. and G.X.; formal analysis, K.F., B.W. and G.X.; investigation, K.F. and G.X.; resources, G.X.; data curation, Y.W., Y.C. and B.W.; writing--original draft preparation, K.F. and X.C.; writing--review and editing, K.F. and X.C.; visualization, J.L. and Y.C.; supervision, Y.C.; project administration, G.X.; funding acquisition, G.X. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the National Natural Science Foundation of China (Nos. 42377344, 42277191), and the Shaanxi Provincial Department of Education Project (Grant No. 23Y057).  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.