Assessment of Polycyclic Aromatic Hydrocarbons Pollution in Lake and Reservoir Sediments in Korea

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that require management as they are continuously formed by natural and anthropogenic processes. We assessed PAH pollution in freshwater sediment in major lakes and reservoirs of Korea. We collected samples of surface sediment in spring 2018; these were sieved to obtain sand, silt and clay (<2 mm). We extracted dry sediment using Hexane:Acetone(1:1) and analyzed the concentration of 16 PAHs by GC-MS. Measured concentration of PAHs was compared with threshold effect concentration(TEC) and probable effect concentration (PEC), and concentration ratio of chemical species was analyzed to track source. PAH concentrations ranged from 13 ng/g-dw to 1 337 ng/g-dw, (median 123 ± 204 ng/g-dw),which are below TEC and are similar or slightly lower than those reported by previous studies. At most sites, the dominant PAH source was natural combustion such as forest fires rather than anthropogenic such as petroleum. In contrast, the site with the highest PAH concentration (1 337 ng/g-dw) in Dae-am reservoir indicated natural and anthropogenic sources. Pollution levels of PAHs in reservoirs and lakes in Korea is not of concern in general. However, some sites with PAHs from anthropogenic sources need to be monitored to investigate possible increase in PAH concentrations in future. Key Words: PAHs, Sediment, Pollution assessment, Pollution evaluation guideline, Composition ratio of 16 PAHs