Distribution characteristics, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in sediments from Haizhou Bay, China

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography-mass spectrometry. Twenty samples were collected from the surface sediments of Haizhou Bay in this survey. This research aimed to identify the PAHs' contamination level, composition pattern, pollution sources, and assess the ecological risk of PAHs. The results showed that the sum of PAH concentrations ranged from 116.6 ng g(-1) to 2414.9 ng g(-1) (mean: 662.42 ng g(-1)), which is higher than the reported values for different wetlands worldwide. Three- and four-ring PAHs (accounts for more than 70% of the total PAH content) were predominant in the wetland sediment. The PAHs source distribution in the surface sediments were determined using diagnostic ratio and PCA/MLR. Consequently, multiple PAHs sources were found. Of the total PAH, 79.25% was derived from vehicular emission, 20.75% from coal combustion. The effect range low/effect range median (ERL/ERM) values indicated a low toxicity risk level. However, the fluoranthene concentrations exceeded the ERL level, and even the ERM level, in some stations. The mean effects range-median quotient (M-ERM-Q) suggests a low ecological risk for the PAHs in the sediments.