Abstract
In this paper, the emission sources of PM10 are characterised by analysing its trace elements (TE) and ions contents. PM10 samples were collected for a year (2019-2020) at five sites and analysed. PM10 speciated data were analysed using graphical visualization, correlation analysis, generalised additive model (GAM), and positive matrix factorization (PMF). Annual average PM10 concentrations (mu g/m(3)) were 304.68 +/- 155.56 at Aziziyah, 219.59 +/- 87.29 at Misfalah, 173.90 +/- 103.08 at Abdeyah, 168.81 +/- 82.50 at Askan, and 157.60 +/- 80.10 at Sanaiyah in Makkah, which exceeded WHO (15 mu g/m(3)), USEPA (50 mu g/m(3)), and the Saudi Arabia national (80 mu g/m(3)) annual air quality standards. A GAM model was developed using PM10 as a response and ions and TEs as predictors. Among the predictors Mg, Ca, Cr, Al, and Pb were highly significant (p < 0.01), Se, Cl, and NO2 were significant (p < 0.05), and PO4 and SO4 were significant (p < 0.1). The model showed R-squared (adj) 0.85 and deviance explained 88.1%. PMF identified four main emission sources of PM10 in Makkah: (1) Road traffic emissions (explained 51% variance); (2) Industrial emissions and mineral dust (explained 27.5% variance); (3) Restaurant and dwelling emissions (explained 13.6% variance); and (4) Fossil fuel combustion (explained 7.9% variance).