Distribution patterns and risks posed of polycyclic aromatic hydrocarbons contaminated in the surface sediment of the Red Sea coast (Egypt)

Abstract

Coastal marine sediment samples collected from 17 locations along the Egyptian Red Sea coast in June 2009 were analyzed for aliphatic, polycyclic aromatic hydrocarbons (PAHs), and total organic carbon (TOC). Total concentrations of 16 Polycyclic Aromatic Hydrocarbons-Environmental Protection Agency (EPA-PAHs) in the studied sediment samples varied from 0.132 to 5.182 μg g−1 with an average value of 1.628 μg g−1 (dry weight). The total aliphatic concentrations fluctuated between 4.232 and 71.874 μg g−1 with an average value of 23.022 μg g−1 (dry weight). The carcinogenic PAHs (PAHCARC) concentrations were ranged between 0.063 and 3.522 μg g−1 (dry weight). The highest PAHs contents found in the samples from Ras Suder (∑5.182 μg g−1), El-Tour (4.052 μg g−1), and Sharm (3.367 μg g−1) locations. Good correlations were observed between the individual PAHs concentrations. The average total organic carbon percent (TOC%) varied between not-detected and 0.35%. The concentration of total pyrolytic hydrocarbons (∑COMB) was higher than the total fossil hydrocarbons (∑PHE), which indicated that the atmospheric fall-out was the significant source of PAHs to the Red Sea marine sediments. Principal component analysis (PCA) was used to determine the sources of hydrocarbon pollutants in the Red Sea sediments. Additionally, individual PAHs compound ratios suggested the pyrogenic origins. Human hazard risk assessment of PAHs was also studied to evaluate the possible risk of contaminated sediments to the public health concerning PAHs intakes.