Concentrations and Source Identification of Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) in Agricultural, Urban/Residential, and Industrial Soils, East of Oran (Northwest Algeria)

ABSTRACT

The aim of this study is to determine potential sources and concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in surface soils devoted to different land uses in northwest Algeria. Microwave-assisted extraction (MAE) and gas chromatography/mass spectrometry (GC–MS) methods were applied to quantify 16 PAHs and 7 PCB congeners in surface soils. The sum of the 16 US-EPA priority PAHs and the 7 European indicator PCBs ranged from 133.7 to 2068.0 ng g⁻¹ and from n.d. to 19.34 ng g⁻¹, respectively. PAHs with four to six fused rings were predominant in soils, and their concentrations ranged from 110.1 to 1768.0 ng g⁻¹. Principal component analysis (PCA) and isomeric ratios showed that pyrogenic processes and petrogenic contributions were the main sources of PAHs, while commercial mixtures of PCBs (Aroclor 1254 and 1260) were sources of PCBs in urban/residential and industrial sites. This is a first screening of data about PAHs and PCBs in soils around a Mediterranean city (Oran, North Africa), and a first step toward a better understanding of the impact of anthropogenic activities on land uses.

KEYWORDS:

• Isomeric ratio
• polycyclic aromatic hydrocarbons
• polychlorinated biphenyls
• principal component analysis
• soil level contamination
• source identification

Acknowledgments

The chemical analyses of this study were performed in the COBRA laboratory, UMR CNRS 6014, University of Rouen-Normandy, Evreux, France. We would like to thank all the members of the COBRA Evreux team directed by Prof. F. Le Derf, for their welcome, access to the required equipment, and all their useful explanations.