Variations in Polycyclic Aromatic Hydrocarbon Contamination Values in Subtidal Surface Sediment via Oil Fingerprinting after an Accidental Oil Spill: A Case Study of the Wu Yi San Oil Spill, Yeosu, Korea

This study determined the PAH contamination variations in the subtidal surface sediment with oil fingerprinting in the Wu Yi San oil spill in Yeosu, Korea, in January 2014. The ∑16 PAHs and ∑alkyl PAHs were investigated in surface sediment and seawater 1 month after the oil spill for 1 year at 3-month intervals in the accident (St. A-F) and adjacent areas (St. 1-20). The averaged ∑16 PAHs and ∑alkyl PAH concentration in the five samplings were 42.2–171.7 ng/g and 211.5–221.8 ng/g, respectively. Comparing the PAH levels in St.E and St.17 indicated a decreased tendency, from 357.9 to 31.1 ng/g dw. in ∑16 PAHs, and from 1900.9 to 211.5 ng/g dw. in ∑alkyl PAHs. The PAHs were not statically correlated between surface sediment and seawater (p > 0.05), implying that the fate of PAHs was rapidly dispersed toward adjacent coasts and beaches. Pyrogenic origin was predominant in 16 PAHs, and petrogenic origin in alkylated PAHs. Notably, C2-D/C2-P and C3-D/C3-P ratios in the accident area during the first sampling were similar to accident oil, but the similarity was not shown in other samplings. Only the C2-naphthalene (St.A), C1-phenanthrene (St.A and St.B), and C2-phenanthrene (the entire accident area points) concentrations were higher than the ERL SQG.