Abstract
Understanding the sources and status of heavy metals in soils is essential for effective risk management. In this study, a typical industrial area was taken as an example. The pollution status of Hg, Cd, As, Pb, Cu, Cr, Zn and Ni were assessed using the pollution index method and potential ecological risk index method. Based on PCA, the APCS-MLR model was used to analyze the pollution sources of heavy metals. Results indicated that the average concentrations of Hg, Cu, Ni, Zn, As, Cr, Cd, and Pb were 0.05×10-6, 26.7×10-6, 19.0×10-6, 64.0×10-6, 6.5×10-6, 54.2×10-6, 0.17×10-6, and 29.5×10-6, respectively, and Hg, Cd, Pb, Zn, Cu, and As exceeded background values of Yantai City by 1.46, 1.40, 1.08, 1.06, 1.03 and 1.02 times. The average concentrations of heavy metals in different land types were arranged in the order of industrial area>agricultural area>residential area, with values of 313.7×10-6, 177.2×10-6, and 175.2×10-6. The average Nemerow pollution index was 1.60, indicating an overall alert-slight pollution level, and the comprehensive potential ecological risk index was 125.1, representing a slight ecological risk. Both the Nemerow pollution index and comprehensive potential ecological risk index demonstrated that the pollution degree followed the order of industrial zone>agricultural zone>residential zone. APCS-MLR identified four pollution sources, that is metal smelting industry, mixed soil parent material and agricultural sources, atmospheric deposition fossil fuel combustion sources, and waste water irrigation dominant mixed sources, with the contribution rates of 40.6%, 33.6%, 10.1%, and 15.8%, respectively. Cd, Zn, Cu, Cr and Pb were mainly derived from metal smelting industry, Ni and As was primarily attributed to mixed soil parent material and agricultural sources, and Hg mainly originated from fossil fuel combustion sources via atmospheric deposition. This study could provide scientific basis for regional soil heavy metal pollution prevention and management.
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