Comprehensive investigation of multi-trace metals/metalloids in urban soil and street dust within Xi'an ancient city wall (NW, China)

摘要

Multi-trace metals/metalloids pollutions prevail in different compartments of the urban environment. Understanding the status of multi-trace metals/metalloids in urban soil and street dust are critical for contaminant control and risks assessment as well as the security development of urban system. In this study, a total of 67 urban soils and 116 street dusts were collected within Xi'an ancient city wall (NW, China) with the purpose of investigating the status of trace metals/metalloids (TMs) like As, Ba, Ce, Co, Cr, Cu, Ga, La, Mn, Nb, Ni, Pb, Rb, Sr, Ti, V, Y, Zn, Zr in comprehensive contaminations and health risks for 0-6 aged children based on the potential ecological risk assessment model and health risk assessment indices. The results illustrated that the strong variation metals of Pb, Co, Cu and Zn associated with anthropogenic sources in terms of traffic and coal combustions discriminated by PMF model, which showed their high contamination levels and potential ecological risks compared to other TMs in related with nature sources. The multi-TMs in urban soils and street dusts posed the significant non-carcinogenic risks of total for children (HItotal 1), however, the total carcinogenic risks of Cr, Co, As, Ni and Pb were in ignored range. It was noted that the ancient city wall with 12 m height like urn environment would trap the multi-TMs emissions from the sources of traffic, coal combustion, natural and soil resuspension, and would enhance the exposure risks from TMs emissions to children consequently, especially for toxic Cr.