Contamination, morphological status and sources of atmospheric dust in different land-using areas of a steel-industry city, China

Abstract

To know about the element composition, morphology and potential Pb-sources of the atmospheric dust in a steel-industry city in southwest China, the atmospheric dust samples were collected from three different land-using areas, including heavy traffic areas (HTA), residential areas (RA) and industrial areas (RA) were analysed by ICP-MS, SEM-EDX and MC-ICP MS. Results showed the atmospheric dust particles in Panzhihua were characterized by spherical, massive, columnar, layered, and irregular morphologies, and the particles containing minerals were mainly composed of quartz, calcite, gypsum, feldspar, dolomite, iron and titanium minerals. The average concentrations of Zn (795.9 μg/g), Pb (225.3 μg/g), Cr (507.3 μg/g), Cu (134.7 μg/g) in atmospheric dust were higher than the local soil background values except Cd (0.86 μg/g). Lead was enriched in these areas, and it was on “significant enrichment” level. The potential ecological risk index (RI) is in low pollution risk in these three areas. The results of lead isotopic ratios showed that the main sources of lead in atmospheric dust in Panzhihua City were smelting, motor vehicle exhaust and soil. Based on the results of the Pb ternary mixed model, these sources contributed an average of 50.97%, 29.41% and 19.62% of the lead in atmospheric dust, respectively.