Abstract:
This study systematically collected 467 cultivated soil samples and 97 leafy vegetable edible part samples from six prefectures in the eastern region of Yunnan Province. Laboratory analyses were conducted to determine basic physical and chemical indicators such as pH, organic matter, and concentrations of heavy metals (As, Hg, Cu, Zn, Pb, Cd, Cr). A pollution characteristic evaluation system and a health risk assessment model were established using the single-factor pollution index method and the United States Environmental Protection Agency (US EPA) health risk assessment model. Spatial distribution patterns of heavy metals were visualized using ArcGIS 10.8. Key findings included: (1) Average concentrations of six heavy metals (excluding As) exceeded Yunnan soil background values by 34%-97%, with Cu exceeding by 0.43 times and Cd by 0.78 times agricultural soil pollution risk screening thresholds. (2) Spatial analysis revealed significant regional Cd contamination, identifying the central region of Yunnan Province around Qujing City as a severe pollution zone (
Pi=3.12), with moderate contamination belts in northern Zhaotong and southern Wenshan (
Pi=1.85-2.43). Cu pollution clustered in the central region (
Pi=1.67), while Zn-Pb composite pollution dominated the Kunming-Yuxi transitional zone in the central and southern regions (
Pi=1.12-1.35). (3) Health risk assessment indicated that carcinogenic risks via ingestion and dermal pathways remained below the 10
−4 safety threshold. However, non-carcinogenic hazard indices for children (HI=1.26) significantly exceeded adult values (HI=0.87), particularly in Qujing City (HI=1.43). This underscores the need to prioritize research on the translocation mechanisms of heavy metals in agricultural products. The multi-dimensional risk assessment provides scientific support for establishing heavy metal pollution prevention systems and vegetable safety early-warning mechanisms in eastern Yunnan's cultivated soils.