Different chemical properties of lead in atmospheric particles from urban roadside and residential areas

Lead in atmospheric suspended particles was fractionized using simple acid extraction to assess differences in chemical properties of lead from roadside and residential areas. The Pb–LIII edge XANES measurement was also challenged to explore the possibilities of contamination from road dust into the air. Results suggest that 0.1 M–HCl extractable fractions of lead at the roadside area are significantly higher than those obtained at the residential area, especially for the coarse mode of the particulate samples. Moreover, the solubility characteristics of the roadside particulate lead have partially overlapped with those of the road dust samples. The XANES spectra for coarse mode of particulate lead also nearly correspond to that of the road dust collected around the roadside area. These results indicate effects by the re–suspension of road dust to the roadside air. However, it is difficult to clear the roadside contamination from specific lead material applied in this study. This might suggest that specific lead compounds do not exist exclusively in atmospheric particles but exist as mixtures or unknown complexes.