Source- and region-specific distribution of polycyclic aromatic hydrocarbons in sediments from Jinhae Bay, Korea

This study surveyed polycyclic aromatic hydrocarbons (PAHs) at 80 sites in sediment from Jinhae Bay, which consists of Masan Bay (MSB), Haengam Bay (HAB), Bay Proper (JBP), Wonmoon Bay (WMB), and Gohyun Bay (GHB). Levels of the EPA 16 priority PAHs, 5 groups of alkylated PAH homologues and 2 biogenic PAHs were determined. Total PAHs (sum of all target PAHs) ranged from 37.0 ng/g to 3,110 ng/g with a mean of 339 ng/g. WMB had the highest concentration (473 ± 665 ng/g: average ± standard deviation) followed by GHB (214 ± 141 ng/g), MSB (175 ± 358 ng/g), JBP (133 ± 86.0 ng/g) and HAB (118 ± 129 ng/g). A tiered-source identification approach using the pyrogenic index, PAH isomer ratios and alkylated PAH double ratios found that both pyrogenic and petrogenic PAHs were dominant, and identified three different source- and region-specific groups. Input pathway tracers, such as butyltins, nonylphenols and dibenzothiophenes, were used to track the main input pathways. A shipyard and urban runoff were identified as the major input pathways of PAHs into GHB, and urban runoff was identified as a major pathway into MSB and WMB. Used crankcase oil, diesel exhaust, tyre debris and asphalt were considered to be the dominant PAH sources in urban runoff. Several PAH compounds exceeded the interim marine sediment quality guidelines for the protection of aquatic environments, among which dibenz[a,h]anthracene exceeded the guidelines in 16% of surveyed sites. Current PAH levels in MSB indicated an improving situation following the implementation of a total pollutant load management system (TPLMS); this is in accordance with other studies. WMB was recognised as an area of concern within this bay, suggesting the update of the TPLMS in this region.