Spatial distribution, source analysis, and risk assessment of polycyclic aromatic hydrocarbons in dredged sediments of Chinese coastal ports

Abstract

In this study, dredged sediment samples were collected from 15 coastal ports in China during dredging operations. The spatial distribution characteristics, potential pollution sources, and possible risks of these sediments were analyzed and assessed to inform sustainable sediment management. GC-MS/MS revealed that the concentrations of the 16 Polycyclic Aromatic Hydrocarbons (PAHs) in 15 samples ranged from 26.0 ng g^-1 to 283 ng g^-1, with a mean value of 72.8 ng g^-1, with 4-6 ring congeners dominating (>60 % of ΣPAHs), and the highest content was benzo[g,h,i]perylene (BghiP) and indeno[1,2,3-cd]pyrene, each accounting for 13 %. Diagnostic ratios showed that the distribution of PAH sources by site location was dominated by mixed combustion; principal component analysis showed that the sources of PAHs at 15 sites were dominated by high-temperature combustion of petroleum and other fossil fuels, supplemented by combustion of biomass fuels and petroleum spills. The distribution of PAHs at different sites is mainly influenced by human activities and natural factors. The results of the risk assessment indicated that potential ecological risks associated with PAHs in coastal ports of China are low, however, benzo[a]pyrene (BaP) and dibenzo[a,h]anthracene (DahA) were the largest contributors to toxic equivalent. The incremental lifetime cancer risk (ILCR) values for adults at every site were in the range of 5.3 × 10^-8-5.2 × 10^-7 while 1.4 × 10^-7-1.4 × 10^-6 for children, indicating that child population pose a greater cancer health risk than adults. This study provides a scientific foundation for the safe disposal and utilization of dredged sediments under the effect of PAH pollution in Chinese coastal ports.

Keywords: Compositional characteristics; Marine sediments; Polycyclic aromatic hydrocarbons (PAHs); Principal component analysis; Regional pollution.