The contents of ten heavy metals (HMs) (Cu, Pb, Zn, Cd, Ni, Cr, Hg, As, Co, and Mn) in 80 surface soil samples (0–20 cm) were investigated in the Pearl River Delta (PRD), Guangdong Province, China. The average contents of Cu, Pb, Zn, Cd, Ni, Cr, Hg, As, Co, and Mn were 16.45, 40.20, 45.10, 0.09, 12.93, 47.93, 0.13, 14.44, 5.68, and 199.66 mg/kg, respectively. The soil quality was generally good, though slightly higher levels (1.17, 1.61, 1.67, and 1.62 times) of soil Pb, Cd, Hg, and As contents were observed compared with the soil background values. The spatial distribution of soil HM pollution in the PRD showed that 36% of sample sites were evaluated as sites without soil pollution, 32% as sites with slight pollution, 20% as sites with nearly moderate pollution, 9% as sites with moderate pollution, and 3% as site with serious pollution. Source apportionment analysis showed that the source of 64.33% of soil HMs in the PRD could be explained by natural and industrial sources, 24.80% by transportation, and 10.87% by agricultural activities.

Heavy metals in groundwater and soil are toxic to humans. An accurate risk assessment of heavy metal contamination can aid in environmental security decision making. In this study, the improved ecological risk index (RI) is used to comprehensively investigate the influence of heavy metals in soil and groundwater within electroplating factories and their surrounding regions. In the non-overlapping area, the RI of soil and groundwater is computed individually, and in the overlapping area, the greater RI of soil and groundwater is employed. Two typical electroplating factories are used to examine the heavy metal distribution pattern. The heavy metal concentrations are compared between Factory A, which is in operation, and Factory B, which is no longer in operation, in order to analyze the heavy metal concentrations and associated ecological risks. Heavy metals continue to spread horizontally and vertically after Factory B was closed. Heavy metal concentrations in groundwater surrounding Factory B are substantially greater, and the maximum concentration exists deeper than in Factory A. Because Cr, Cu, and Hg in soil contribute significantly to the RI, the primary high RI region is observed at Factory A and the region to the southwest. The RI of Factory B demonstrates a broad, moderate risk zone in the west and southwest.