Characterization of PM10 atmospheric aerosol at urban and urban background sites in Fuzhou city, China
PM10 aerosol samples were simultaneously collected at two urban and one urban background sites in Fuzhou city during two sampling campaigns in summer and winter. PM10 mass concentrations and chemical compositions were determined. Water-soluble inorganic ions (Cl-, NO3-, SO42-, NH4+, K+, Na+, Ca2+, and Mg2+), carbonaceous species (elemental carbon and organic carbon), and elements (Al, Si, Mg, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, and Pb) were detected using ion chromatography, thermal/optical reflectance and proton-induced X-ray emission methods, respectively. PM10 mass concentrations, as well as most of the chemical components were significantly increased from urban background to urban sites, which were due to enhanced anthropogenic activities in urban areas. Elements, carbonaceous species and most of ions were more uniformly distributed at different types of sites in winter, whereas secondary ion SO42-, NO3- and NH4+ showed more evident urban-background contrast in this season. The chemical mass closure indicated that mineral dust, organic matters, and sulfate were the most abundant components in PM10. The sum of individually measured components accounted for 86.9-97.7% of the total measured PM10 concentration, and the discrepancy was larger in urban area than in urban background area. According to the principal component analysis-multivariate linear regression (PCA-MLR) model, mineral dust, secondary inorganic ions, sea salt, and motor vehicle were mainly responsible for the PM10 particles in Fuzhou atmosphere, and contributed 19.9, 53.3, 21.3, and 5.5% of PM10, respectively.
