Environmental Risk Assessment of Heavy Metals in Cultivated Soils Around Industrial Area and Source Identification under APCS-MLR Model: a Case of Suzhou in Northern China

To investigate the impact of industrial activities on the environmental accumulation and the health risks to humans of heavy metals in urban soils, the cultivated soil samples around different industrial areas were collected and analyzed. The heavy metal concentrations in the soil samples were in the decreasing order Mn>Zn>Cr>Ni>Cu>Pb>As>Sn>Cd>Hg, and the average concentrations of all heavy metals exceeding the corresponding background values. In addition to Cd and Hg, all the other eight metals were classified as low ecological risk; Cd had low, moderate, and considerable ecological risk and Hg were in low, high, and very high ecological risk. The proportion of RI in the four ecological risk levels of low risk, moderate risk, considerable risk and high risk were 69.6%, 13%, 8.7% and 8.7%, respectively. All Mn and some Cr pose non- carcinogenic risk to children primarily through inhalation exposure. Carcinogenic risk is Cr>Ni>As>Pb>Cd, and the exposure route is mainly by ingestion. For children, Cr, Ni and As were high carcinogenic risk and Pb, Cd were acceptable carcinogenic risk; for adults, Cr and Ni were high risk, As was acceptable risk, and Pb and Cd were no risk. The results of the APCS-MLR receptor model showed that the percentages of vehicle emission sources, coal transport industrial sources, coal-fired power plant sources and natural sources were 27.8%, 25.2%, 8.7% and 38.3%, respectively.