Comprehensive assessment of pollution status, health risks and source apportionment of heavy metals in surface wetland soils of Yellow River Delta using Monte Carlo simulation and positive matrix factorization

Excessive heavy metals (HMs) exposure in surface soils may cause non-negligible health risks to human beings; however, the potential health risk assessment of HMs in Yellow River Delta wetland (YRDW) soils has rarely been evaluated. In this study, we sampled surface wetland soils from ten typical functional areas in YRDW, assessed the HMs pollution status, evaluated their potential health risks, stimulated their probabilistic distributions of health risks and analyzed their potential source apportionment using Positive matrix factorization and Monte Carlo simulation. Enrichment factor (EF) and geo-accumulation index (Igeo) indicated significant anthropogenic impacts, particularly in oil-contaminated sites, while Sediment Quality Guidelines (SQGs) comparison results suggested potential ecological risks, especially for As and Ni, which were occasionally above threshold effect levels. The potential health risks based on Monte Carlo simulations revealed no non-carcinogenic health risks to all populations, but highlighted potential carcinogenic risks within the acceptable range (1E-06 to 1E-04), especially for children. Positive Matrix Factorization (PMF) identified primary HMs sources as industrial emissions, agricultural activities and local geochemical background. This study underscores the need for continuous monitoring and remediation to mitigate health and ecological risks in the YRDW soils.