Source identification of polycyclic aromatic hydrocarbons in surface sediments of Pohang New Harbor, South Korea, using compound-specific stable carbon and hydrogen isotope analysis

초록

Compound-specific isotope analysis (CSIA) of carbon and hydrogen provides a robust approach for identifying the sources and quantifying contributions of polycyclic aromatic hydrocarbons (PAHs) in complex coastal industrial environments. In this study, dual-isotope CSIA was applied to sediments from Pohang New Harbor, Korea, integrating molecular concentration and composition data with isotopic measurements to apportion PAH sources. Molecular compositions varied among environmental matrices, with the relative contribution of high-molecular-weight PAHs (HMW-PAHs, ≥4 rings) becoming increasingly dominant during transport. In contrast, the δ13C and δ2H values of HMW-PAHs exhibited coefficients of variation consistently below 10%, indicating their conservative behavior and reliability as source tracers. Dual-isotope plots and principal component analysis distinguished four source-related groups associated with differences in fuel type and combustion conditions. A Bayesian isotope mixing model indicated that coal debris contributed 54% of total PAHs in harbor sediments, partially combusted coal 37%, liquid fossil fuel combustion 5%, and mixed coal and fossil fuel sources 4%. Overall, 74% of PAHs originated from coal-related activities, highlighting the dominant role of coal handling, storage, and particle transport in this industrial harbor. This study demonstrates that combining dual-isotope CSIA with end-member modeling provides a rigorous framework for precise PAH source apportionment in dynamic coastal environments. © 2026 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

키워드