Characteristics and potential risk assessment of heavy metal contents in urban soil, Liaoyang City

The contents and pollution degree of As, Cd, Cr, Cu, Hg, Ni, Pb, Zn and other elements in surface soil samples of Liaoyang urban greenbelt were comprehensively analyzed by pollution load index method and ecological risk index method.The results show that, except As, the concentrations of other seven heavy metal elements in soil is higher than the national background value, of which Hg, Cd are the main pollution elements, and the degree of their contamination has reached heavy and moderate respectively.The trace elements of Zn, Pb, Cu, Cr and Ni are in slight pollution, while As is basically free of contamination.The evaluation of the ecological risk shows that Hg and Cd elements are the main ecological risk factors, and Hg and Cd belong to strong and medium ecological risk respectively.In general, Liaoyang City has slight heavy metal element pollution with medium potential ecological risk.The soil ecological environment in the new city is better than that in the old one, and it is recommended to further play the role of dredging function of the new city to relieve the urban pressure.