Concentration level, distribution model, source analysis, and ecological risk assessment of polycyclic aromatic...

To master the distribution patterns and environmental risk of 16 USEPA preferential polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Laizhou Bay, 20 samples were collected and investigated in this survey. The average PAH concentration in these sediments ranged from 268.97 ng/g to 895.37 ng/g with an average of 612.52 ng/g, thereby suggesting a relatively low PAH pollution in Laizhou Bay compared with other bays in the world. Tricyclic PAHs account for 79% of the total PAH content and were eventually identified as the most crucial component of these sediments. The PCA-MLR results identify fossil fuel combustion, biomass burning, and coke oven as the main sources of PAHs that account for 26.69%, 67.16%, and 6.15% of the total PAH concentration in the collected sediments, respectively. The effect range low/effect range median (ERL/ERM) reveal the low toxicity of PAHs in these sediments. However, the concentration of Fle at each survey site exceeds the ERL level. Meanwhile, the mean effects range-median quotient (M-ERM-Q) indicates the low level of ecological risk of PAHs in the surface sediments from Laizhou Bay. However, the contingency risk of Fle and Phe cannot be ruled out.