LIN Manli¹, PENG Weihua², ZHANG Binzhen³, WANG Yao⁴

(1.School of Resources & Civil Engineering, Suzhou University, Suzhou 234000, China;
2.School of Space and Environment, Beihang University, Beijing, 100191, China;
3.Suzhou Meteorological Bureau, Suzhou 234000, China;
4.College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China)

Abstract: In order to analyze the pollution characteristics and ecological risk of heavy metals (HMs) in street dust of coal resources cities in China, 23 sampling sites in Suzhou City were selected and periodically sampled for 12 months throughout the year. A total of 276 samples were collected, and the concentrations of selected HMs (e.g. Cr, Cu, Mn, Pb, V and Zn) were examined with X-ray fluorescence spectrum analyzer. Result show that the mean concentrations of Cr, Cu, Mn, Pb, V and Zn were 112.9, 27.5, 410.3, 45.2, 75.6 and 225.3 mg/kg, respectively. With the exclusion of Mn and V, mean contents of the other four HMs are all exceeding their background values in soil of the study area. Results of geo-accumulation index reveal that Cu, Mn and V rank unpolluted, while Cr and Pb rank unpolluted to moderately polluted, and Zn ranks moderately polluted. The pollution load indexes of the selected HMs in each month are all between 1 and 2, suggesting unpolluted to moderately polluted level. Although the potential ecological risks of single heavy metal and the compound six HMs both classified as low ecological risk level totally, the spatial distribution of risk indexes (RI) shows that high content areas of RI are mainly located near the districts where human activities frequently, indicating that the concentrations of HMs and their ecological risks are significantly affected by anthropogenic activities. Meanwhile, Concentrations of HMs and their spatial and temporal distribution are also influenced by the direction and speed of wind of the study area.

Key words: street dust; heavy metal; pollution characteristics; ecological risk; coal resources city

EARTH AND ENVIRONMENT Vol.45, No.2, Tot No.316, 2017, Page 185-192