Monitoring and Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Alexandria City, Egypt

ABSTRACT

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in the total suspended particulate (TSP) were measured simultaneously between January 30, 2015 and February 11, 2016 at urban, suburb, and rural sites at Alexandria City, Egypt, using pesticide samplers. Samples were extracted and analyzed using chromatography–mass spectrometric (GC–MS). There was a significant difference in concentrations between the three sites, and between particle- and vapor-phases. Mean total PAH concentrations were 502.48, 322.57, and 417.23 ng m⁻³ for the urban, the rural, and the suburban sites in particulate-phase and were 723.49, 402.26, and 543.15 for the same sites in vapor-phase, respectively. At the three sites, the most abundant compounds determined were Benzo[k]fluoranthene (BkF), followed by Benzo[a]pyrene (BaP) and Indeno [1,2,3-cd] pyrene (IcdP). These high molecular weight compounds are carcinogenic and known to originate mainly from vehicular emissions. The diagnostic ratios indicated PAHs in urban and suburban sites were predominantly from gasoline and diesel engines, while that in rural site was from biomass burning. Characterization of the emission sources was further substantiated by significant correlation between individual PAH species.

KEYWORDS:

• Alexandria
• ambient levels
• chemical speciation
• emission
• polycyclic aromatic hydrocarbons (PAHs)
• spatial variation

Acknowledgments

Authors are indebted to anonymous reviewers for their invaluable comments and suggestions.