Spatial distribution and source analysis of heavy metals in soils influenced by industrial enterprise distribution: Case study in Jiangsu Province.

Heavy metal pollution is frequent in China and has received increasing attention globally. This study investigated the influence of Chinese industrialization and urbanization on soil environmental quality. Soil samples from Jiangsu Province were collected, the Cd, Pb, Cr, Cu, Zn, Hg, and As contents were measured, and their spatial variability structure, spatial distribution pattern, and pollution degree were analyzed. The mean values of Hg, Cd, Pb, Cr, Cu, and As were all higher than the background values in Jiangsu Province. Cr and As levels represented moderate pollution, Cu, Zn, Cd, and Pb represented mild pollution, Cr and As represented slight pollution, and Hg was not a pollutant. Spatial distribution patterns were both zonal and concentrated in nature. High concentrations of heavy metals were distributed in developed cities and industrial parks along the Yangtze River. Soil heavy metal pollution showed a decreasing trend from south to north, consistent with the economic gradient. Industrialization had the greatest influence on the spatial heterogeneity of heavy metal pollution. Cr, Cu, Zn, and As were affected by both natural and anthropogenic sources, while Cd and Pb were mainly affected by the latter. Hg was mainly derived from industrial activities such as petrochemical production. There was spatial consistency between industrial enterprise distribution and soil heavy metal pollution with a tendency toward composite pollution accumulated by multiple elements in the soil surrounding industries.