Distribution of polynuclear aromatic hydrocarbons in sediments from the Seki River system and coastal area near the river mouth.

Abstract

Horizontal distributions of 8 polynuclear aromatic hydrocarbons (PAHs), i.e. pyrene (Py), fluorantene (Fl), benzo [a] anthracene (B [a] A), benzo [k] fluorantene (B [k] F), benzo [b] fluorantene (B [b] F), benzo [a] pyrene (B [a] P), benzo [ghi] perylene (B [ghi] P) and perylene (Per), in sediments from the Seki River and coastal area near the river mouth were measured. Sediment cores from off the river mouth were also analyzed to provide data on historical changes of the 8 PAHs. Concentrations of the total 8 PAHs in the river sediment, the coastal sediment and the sediment core were ranged from <2.6 to 8119, 5.0-298 and 47.9-260 ng/g dry weight, respectively. B [a] P concentration, which was correlated to the other 6 PAHs except for Per, was ranged from <0.1 to 369 ng/g dry weight in the river sediment, 0.3-12ng/g dry weight in the coastal sediment and 0.8-19ng/g dry weight in the sediment core. Except for Per, every PAH-concentration per ignition-loss (PAH/IL) in the river sediment was high at downstream and extremely at the places where indutrial wastewater flowed. PAH/IL in the coastal sediment and surface of the sediment core which located at the places where suspended materials were flowed out from the Seki River was also high, and each PAH-concentration per B [a] P-concentration in the coastal sediment resembled those in the river sediment, suggesting that the river is an important route for supplying PAH to the coastal sediment. On the other hand, it seems that most of Per in sediment originated from natural source and the naturally derived Per-concentrations/IL in the sediment core was estimated at 1.4±0.32 mg/kg.