[Spatial Distribution and Source Apportionment of Soil Heavy Metals Around a Typical Industrial Park in Central South...

A total of 242 sampling points were established around a typical industrial park in central-southern China, where 726 soil samples were collected from three depths. The contents of Cd, Pb, Zn, As, and Ni were measured, followed by spatial distribution pattern mapping and potential pollution zoning using sequential Gaussian simulation. Source apportionment was quantitatively analyzed through positive matrix factorization. The results indicated that surface layer contents of Cd, Zn, Pb, and As were significantly higher than those in the lower layers, with high-value areas concentrated in the southern and eastern parts of the study area. In contrast, Ni exhibited similar concentrations across all three depths, showing predominantly high values in northern and western regions. Pollution zoning revealed high-risk areas predominantly in southern and eastern sectors, where Cd demonstrated the highest contamination risk. Notably, the probability of Cd exceeding the regulatory threshold for soil pollution risk in agricultural land exceeded 95% across 80.45% of the total study area. Source apportionment showed that industrial activities and transportation collectively contributed 87.86%, 76.47%, and 68.68% to Cd, Zn, and Pb pollution, respectively. Agricultural practices involving irrigation and agrochemical application accounted for 69.23% of As contamination, while natural sources dominated Ni inputs with an 85.62% contribution.