COMPARATIVE ANALYSIS OF SOIL HEAVY METAL POLLUTION ON DIFFERENT ROADS: A CASE STUDY IN A TYPICAL INDUSTRIAL CITY OF CHINA

A total of 22 surface soil samples beside three different types of roads (trunk road, sub-trunk road and branch road) collected in Ma'anshan City, Anhui Province, China, were analyzed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and multivariate statistics. Besides, spatial distribution characteristics analysis was employed to identify the possible sources. The results indicate that the average concentrations of heavy metals following in the order of Mn > Pb > Co > Cr > As > Cd, and Cr content in the sub-trunk road are much lower than that in the trunk road and branch road. Geoaccumulation index shows that heavy metal pollution exists beside urban roads. Moreover, Cd pollution is the most serious, while Co and Pb are at a high pollution level. Potential ecological risk index shows that Cd poses a severe ecological risk; Pb and Co reach the medium ecological risk degree. Furthermore, two principal components (PC1 and PC2) of the heavy metal elements have been extracted by factor analysis, and the cluster analysis was consistent with the factor analysis. Based on spatial distribution characteristics, two sources have been identified: PC1 (Pb, Mn, Co) are contributed mainly by industrial pollution, and PC2 (Cd, As, Cr) are primarily influenced by traffic pollution.