Partitioning and mobility behavior of metals in road dusts from national-scale industrial areas in Korea

In this study, we investigated the characteristics of heavy metal contamination in road dusts collected from industrial areas in Korea. A total of 12 sampling sites, including nine sites in three different industrial complexes (ICs), two IC vicinity areas and one background area, were selected for this study. The collected road dusts were divided into four categories. The heavy metals (Cd, Cu, Pb, Zn, and Ni) were extracted from the road dust by an aqua regia extraction method and analyzed by atomic absorption spectrometry. The highest concentrations of Cd, Cu, and Pb were identified in road dusts from areas near the non-ferrous metal IC, followed by those from the petrochemical IC. The petrochemical IC and the mechanical/shipbuilding IC showed the highest concentrations of Ni and Zn in their road dusts, respectively. The concentration of heavy metals in the road dusts collected from the IC vicinity areas, even those located in a rural environment, were very high. The concentration of heavy metals increased with decreasing particle size of the road dusts. This study also analyzed the mobility of the heavy metals in the road dusts using partial sequential extraction with the Tessier procedure. The order of mobility identified, based on exchangeable and carbonate fractions of the heavy metals, was Cd > Zn > Pb > Cu > Ni.