Pollution history, source and transport path for PAHs in dated sediment cores from four lakes in Northern China

Abstract

In this paper, concentrations and compositions of 16 USEPA priority control polycyclic aromatic hydrocarbons (PAHs) in the sediment cores collected from four lakes in northern China were analyzed. Pollution history of PAHs were reconstructed based on 210Pb and 137Cs age-dating. Positive definite matrix factorization (PMF) was adopted to quantify the source and relative contribution rate of PAHs. Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) was used to analyze the input trajectory and potential pollution source areas of PAHs under the influences of different air masses. Potential ecological risks of PAHs were assessed based on Effects Range Low (ERL) and Effects Range Median (ERM). The average concentrations of 16 PAHs in sediment cores from four lakes were 596.53 ng/g, 596.47 ng/g, 216.91 ng/g, and 197.57 ng/g dry weight, respectively. The sedimentary history tended to show a similar pattern. It increased from the bottom to the surface layers, with a dominance of 3- and 4- rings PAHs. Due to the expansion of human activities, there has been a rapid increase in 16 PAHs in the sediments of the four lakes since the late 1970s. According to source apportionment, the combustion of fossil fuel combustion contributed 34.71%, 60.80%, 58.12%, 53.02%, to the PAHs in the four sediment cores, respectively, which were the main sources. HYSPLIT showed that the atmospheric inputs of PAHs in the sediment cores of CG Lake, HL Lake, WLS Lake and BST Lake was mainly local air masses with a short distance, and the input directions were southeast, east, southwest, and northwest, accounting for 16.21%, 12.94%, 15.54%, 22.19% of the total trajectory, respectively. Although there was no potential ecological risk for Σ16PAHs, toxicological assessment suggested that Flu and Ace in the four lakes and Ant in CG Lake could create negative biological consequences. More attention should be paid to seven teratogenic and carcinogenic PAHs, the concentrations of which tended to increase in recent years.