Distribution, Risk Assessment, and Source Analysis of Heavy Metals in Surface Sediment of Urban Lakes in Wuhan City

<p indent="0mm">As key ″sinks″ and secondary ″sources″ of heavy metals in lake systems, sediments play a critical role in the biogeochemical cycling of heavy metals by influencing their transformation, mobility, and release. This study focused on 15 urban lakes in Wuhan, analyzing the distribution of nine heavy metals in surface sediments, assessing their pollution status and ecological risks, and identifying their primary sources and contributions. The results revealed that Cd, Zn, Cu, and Pb concentrations in 80%, 73%, 60%, and 47% of the samples, respectively, were approximately twice their background levels. Both the geo-accumulation and potential ecological risk index indicated severe Cd pollution and significant ecological risks in the sediments of Wuhan′s urban lakes. Correlation analysis, principal component analysis, and the positive matrix factorization–multiple linear regression receptor model identified anthropogenic sources such as traffic and industrial activities as the major contributors to Pb, Zn, Cu, Cr, and Cd, while Co, Mn, Ni, and As concentrations were largely influenced by geological background. These findings provide a scientific basis for targeted lake pollution control and ecological restoration, derlivering valuable data to develop pollution source control strategies.