[Characterization and Risk Assessment of Heavy Metal Pollution in Amphibian Habitats in the Yellow River Basin].

values of the six metals followed the order： Cd>Zn>Cr>Cu>Ni>Pb， indicating moderate to severe pollution levels for Cd. Due to the elevated Cd concentrations， the overall ecological risk of heavy metals in the study area was at a relatively high level， with higher risks in the middle and lower reaches and the lowest in the source region. Source analysis revealed that Cu， Zn， Cd， and Pb mainly originated from industrial mining， metal smelting， and transportation activities， while Ni and Cr were primarily derived from agricultural activities and the weathering of parent materials. To mitigate the ecological hazards posed by heavy metal contamination in the Yellow River Basin and improve habitat quality， it is essential to strengthen the regulation of Cd and enhance environmental management in industrial pollution hotspots across the basin.