PAHs in the Northwestern Japan Sea

Abstract

This chapter discusses the level of PAH pollution in the surface and deep waters of the northwestern part of the Japan Sea (NWJS). The investigated area included the river estuaries of the NWJS basin, the coastal regions, and the pelagic zone of the Japan Sea. As to spatial distributions, the concentration of 13 total PAHs ranged from 6.5 to 66.5 ng/L for river estuaries of South Primorye, and the concentration of 8 total PAHs was 31.2–105 ng/L for the Amur River Estuary. In the bays, the PAH content was 8–148.7 ng/L. The PAH pollution directly correlated with anthropogenic loads on surrounding territories. The open part of the Japan Sea demonstrates that the particulate PAH concentrations varied from 1.2 to 4.4 ng/L in 2009. There was an increasing trend for PAH content from the northeast of the Japan Sea to the southwest. Additionally, PAHs from coal and wood combustion predominated in surface waters of the north of the Japan Sea, while the main source of PAHs in the southwest of the Japan Sea was oil product combustion. In 2010 total PAH content ranged from 7.4 to 10.2 ng/L. The seasonal variation in the PAH concentrations was associated with emissions from the central and domestic heating systems. The results of the PAH distributions in the water column show that surface and intermediate waters (0–500 m) were more polluted than deep waters. Observed enhanced PAH levels on the depths from 30 to 500 m corresponded to biological pump activity.