Polycyclic Aromatic Hydrocarbons in the Estuaries of Two Rivers of the Sea of Japan.

The seasonal polycyclic aromatic hydrocarbon (PAH) variability was studied in the estuaries of the Partizanskaya River and the Tumen River, the largest transboundary river of the Sea of Japan. The PAH levels were generally low over the year; however, the PAH concentrations increased according to one of two seasonal trends, which were either an increase in PAHs during the cold period, influenced by heating, or a PAH enrichment during the wet period due to higher run-off inputs. The major PAH source was the combustion of fossil fuels and biomass, but a minor input of petrogenic PAHs in some seasons was observed. Higher PAH concentrations were observed in fresh and brackish water compared to the saline waters in the Tumen River estuary, while the PAH concentrations in both types of water were similar in the Partizanskaya River estuary, suggesting different pathways of PAH input into the estuaries. The annual riverine PAH mass flux amounted to 0.028 t/year and 2.5 t/year for the Partizanskaya River and the Tumen River, respectively. The riverine PAH contribution to the coastal water of the Sea of Japan depends on the river discharge rather than the PAH level in the river water.

Polycyclic Aromatic Hydrocarbons in Surface Water of the Southeastern Japan Sea.

Surface water samples were collected at 15 sampling sites in the southeastern Japan Sea along the Japanese Archipelago for analysis of polycyclic aromatic hydrocarbons (PAHs). Water samples were fractionated by filtration through a glass fiber membrane (pore size 0.5 µm) and analyzed by high-performance liquid chromatography with fluorescence detection. Thirteen PAHs having 3 to 6 rings were found in the dissolved phase (DP) and 12 were found in the particulate phase (PP). The total (DP+PP) PAH concentration ranged from 6.83 to 13.81 ng/L with the mean±standard deviation (S.D.) concentration of 9.36±1.92 ng/L. The mean±S.D. PAH concentration in the DP and PP was 5.99±1.80 and 3.38±0.65 ng/L, respectively. Three-ring PAHs predominated in the DP, while the proportion of 4-ring PAHs was higher in the PP. The mean total PAH concentration in the southeastern Japan Sea was higher than the concentration in the northwestern Japan Sea (8.5 ng/L). The Tsushima Current, which originates from the East China Sea with higher PAH concentration, is considered to be responsible for this higher concentration.