Source Identification and Spatial Variation Analysis of Potentially Hazardous Elements in Topsoil Based on Multi-Source Data in Longkou City, China

This study identified the sources and analyzed the spatial variation of potentially hazardous elements (Cr, Cu, Ni, Pb, Zn, Cd, As, and Hg) using land use, soil parent material, slope and elevation, combined with geostatistics and multi-source statistics in Longkou city, China. The results showed that Cr, Ni, and As were mainly controlled by natural factors such as granite and elevation, and high- concentration areas were mainly in the northeast and south of the study area. Higher Hg levels were derived from mixed sources, including industrial and transportation activities in the central urban area. Cd was mainly controlled by mixed sources, and its spatial variation was affected by elevation, industrial activities, and granite. Pb came from mixed sources, and its spatial variation was influenced by smelting and gilding industries and alluvial sediments. Cu originated from artificial sources and was affected by industrial and agricultural activities; it was mainly distributed in mining areas in the northwest and orchards in the southeast of the study area. Zn came from mixed sources, and its spatial variation was affected by industry, agriculture, and alluvial sediments; high concentrations were mainly found in mining areas in the northwest and orchards and farmland in the south.