Identification of elemental composition of PM2.5 collected in Makkah,Saudi Arabia,using EDXRF

Makkah city, Saudi Arabia, represents the most attractive place for religious tourism for Muslims all over the world. More than 15 million visitors come to the city per year, especially during Hajj (pilgrimage) and Ramadan seasons. Due to the lack of air quality assessment data for Makkah, measurement of different pollutants in Makkah is of great interest. In the present work, airborne particulate matter with aerodynamic diameter equal to or less than 2.5 µm (PM_2.5) has been collected from two different sites in the city, namely the Grand mosque and Al‐Shraie, from December 2012 to January 2014 covering the different seasons of the year. The average mass concentrations at the sites are comparable, 48 ± 28 µg/m³ and 53 ± 27 µg/m³ for the Grand mosque and Al‐Shraie sites, respectively. For quantitative elemental analysis, energy dispersive X‐ray fluorescence (EDXRF) spectrometry was used. Twenty elements (Si, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Se, Br, Rb, Sr and Pb) were quantified in the PM_2.5 samples. Fortunately, the obtained results of Pb and S are below the maximum allowance level of European commission for air quality. However, the average concentration of Ni in both sites is close to the maximum allowance level 20 ng/m³ and the Ni concentration reaches 25 ng/m³ at Grand mosque site during August 2013. Based on the Positive Matrix Factorization (PMF) analysis, four source factors were found, some signalling mixed sources, showing the main influence from mineral dust, anthropogenic/industrial sources and a marine source. Copyright © 2017 John Wiley & Sons, Ltd.