Chemical characteristics of atmospheric fallout in the south of Xi'an during the dust episodes of 2001-2012 (NW China)

Atmospheric fallouts (AFs) were collected in the south of Xi'an, NW China, during the dust episodes of 2001-2012. The chemical compositions of AFs dominated by coarse particles (PM10-50), including of trace elements and water-soluble ions (WS-ions), were identified and quantified by wavelength dispersive X-ray fluorescence spectrometry (WDXRF) and FTIR spectroscopy. The heavy metal hazards containing in AFs, for example, Cr, Cu, Ba, Sr, As, Pb and Zn were highly influenced by anthropogenic activities (e.g. traffic-related, non-ferrous metal industries, combustion of fuels, coal fly-ash sources). While, Al, Fe, Si, K, Ca, Na, Mg, coupled with the trace elements Co, V, Ce, Mn, Ni, Ga, Y, Rb, La, Br, Cs were predominated by crustal material sources. Simultaneously, the water-soluble ions (WS-ions) of NH4+, SO42−, SO32−, NO3−, SiO44−, HSO4− possibly originated from coal combustion with the aid of multivariate statistical analysis. This made it possible to trace the amount of trace element pollutants in time and in relation to dust storm conditions.222