Sources and spatial distribution of heavy metals and arsenic in soils from Xiongan New Area, China

Conducting the soil environmental condition survey and accessing the distribution and potential sources of heavy metals and arsenic in soils in Xiongan New Area are of great significance for the land resources and environment management of the district. Based on the data of soil survey samples in the Xiongan New Area, spatial distributions of the elements (As, Hg, Cd, Cu, Pb, Zn, Ni and Cr) are analyzed and computed by using geostatistics and ArcGIS techniques. A combination of spatial analysis, multivariate statistical analysis, and positive matrix factorization model is used to assess the sources of these elements. The result show that the soil quality is good and the pollution risk is low. Approximately 4.35% of the soil samples for Cd and Cu have total concentrations higher than the risk screening values for soil contamination of agricultural land, and lower than the risk control values for soil contamination of agricultural land. However, moderate and significant enrichment in Cd, Cu, Pb, Zn and Hg in the surface soils was observed compared with their background values of Hebei province. The contents of As, Cd, Cu, Pb, Zn, Ni and Cr exhibite a gradually increasing trend from north to south. These elements principally concentrate in the southwest of the study area. The distribution of Hg is relatively dispersed, and the high-values are mainly located in the urban and industrial areas. The vertical distributions of heavy metals and arsenic in soils of different landuse types are dominantly controlled by physicochemical factors such as pH, organic carbon, and Fe/Al oxides. Anthropogenic sources contribute 67.12% of the heavy metal concentrations in soils, indicating the great influence on soil heavy metal accumulation. Hg is dominated by atmospheric deposition related to anthropogenic emissions such as coal combustion and smelting activities. As is principally affected by industrial activities. Cd, Cu, Pb and Zn are influenced by anthropogenic activities such as industrial production, sewage irrigation and vehicle emission.