Elemental composition and source apportionment of atmospheric aerosols collected from urban and residential areas of Jordan using multi-secondary targets energy dispersive X-ray fluorescence

In the present work, the elemental composition of airborne particulate matter with aerodynamic diameter <= 2.5 mu m (PM2.5) collected from urban and residential areas of Jordan was determined and the associated pollution sources were identified. The sampling was performed in sites located in Zarqa and Amman during the winter and spring seasons of 2014/2015. The quantitative elemental analysis of nineteen (19) elements was carried out using an energy dispersive X-ray fluorescence (EDXRF) spectrometer utilizing the polarization geometry and the three secondary targets (CaF2, Ge and Mo). Remarkable enhancement in terms of analytical range, low Z-elements quantification (including Al, Na and Cl), and limits of detection were achieved. The total concentration of the PM2.5 samples in winter is higher than its concentration during spring due to the lower dispersion of atmospheric aerosols. Despite the lower concentration of PM2.5 collected from the urban location, Zarqa, high concentrations of the elements Ca, V, Cu, Zn and Pb were recognized which could be an indication to the industrial and anthropogenic activities at Zarqa. The average concentration of Ca in the urban area is approximately twice the concentration in the residential site which indicates the heavy cement industries at Zarqa city. A similar concentration of S was found in both locations which indicates the same anthropogenic sources such as consuming fuels and electrical power plants. The average percentages of the total detected elements at Amman and Zarqa are equal to 48% and 86% from the total mass concentration, respectively, which confirm the heavy anthropogenic activities at Zarqa. Based on the calculations of Pearson's correlation coefficients and the principle component analysis, source apportionments of the detected elements in the two locations were evaluated.