Contamination and Ecological Risk Assessment of Heavy Metals in the Street Dust of Longyan, China

Street dust collected from 53 sampling sites in six regions in Longyan City, Fujian Province, China was examined for concentrations of heavy metals (Pb, Cd, Cu, Zn, and Hg). Pearson correlation coefficient, cluster, and principal component analyses were conducted to identify the relationship between the contaminants in the street dust and their probable sources. The pollution levels and potential ecological risks of heavy metals were assessed using the methods of potential ecological risk index. The concentration of heavy metal in the street dust of Longyan City was higher than the soil background values in China. Five kinds of metal in the sample dust exhibited strong variability, and their coefficients of variation were sorted as follows: Cu < Cd < Zn < Hg < Pb. The potential pollution sources of the heavy metals were grouped into three main categories. Traffic pollution is the first category, with Pb, Cd, and Zn as the major pollutants. The second category is copper pollution caused by copper-zinc ore mining and smelting emissions. The third category is mercury pollution generated by industrial and coal-fired processes. The potential ecological hazard index of heavy metals in Longyan reached a very strong ecological risk level, except for Caoxi Road, which exhibited a strong ecological risk..