[Temporal distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons in sediment core from Miyun reservoir].

The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was measured in sediment core from Miyun reservoir, and the possible sources and the potential risk assessment also have been identified. The aim of the present work is to understand the temporal trend of PAHs in Miyun reservoir recently. The concentrations of sigma PAH16 in sediment ranged from 618.5 ng/g to 1087.9 ng/g, and roughly, increased continuously from the bottom (16 cm under the surface) to the surface sediment. The PAHs in sediment core were mainly composed of phenanthrene and fluorene. The concentrations of phenanthrene and fluorene in sediment core were 236.1-417.9 ng/g and 91-130.8 ng/g, respectively. Both of them accounted for 47.2%-58.1% of the sigma PAH16 in sediments. Nevertheless, high-rings aromatic hydrocarbons (5-6 rings) were increased steadily in recent years. PAHs compositional profile indicated that the main source of PAHs was originated from the combustion of coal and biomass. However, the vertical profiles of Flu/Flu + Pyr and INP/INP + BghiP ratios suggested that the vehicles emission was increased very recently. Risk assessment suggested that PAHs in sediment from Miyun reservoir was no significant biological impairment, and low toxicological risk of PAHs was found up to now.