Distribution of Freely Dissolved Polycyclic Aromatic Hydrocarbons in the Yellow Sea: Application of Improved Passive Sampling Technique

Abstract

A high-speed rotation-type passive sampling device (HSR-PSD) was designed to effectively measure the freely dissolved hydrophobic organic contaminants in an aquatic environment, and the operating conditions of the HSR-PSD were optimized. In addition to the HSR-PSD, a conventional high-volume water sampler was applied to the Yellow Sea near Korea, and the distributions of three environmental phases of polycyclic aromatic hydrocarbons (PAHs) were investigated. The HSR-PSD, operating for under 12 h at 1000 rpm, can measure the freely dissolved concentrations of PAHs up to log K-OW = 6. Total freely dissolved PAH concentrations obtained from the HSR-PSD were from 0.67 to 1.9 ng/L in the Yellow Sea. The PAH levels were higher by one order of magnitude than those in other oceans. Concentrations of PAHs in dissolved and particulate phases ranged from 10 to 20 ng/L and from 0.0062 to 0.060 ng/L, respectively. Unlike the spatial distribution of dissolved PAHs, the concentrations of freely dissolved PAHs in water and predicted PAHs in fish are higher in the central regions than in coastal areas of the Yellow Sea. Locations with high bioavailable PAHs are adjacent to identified potential sources, demonstrating that PAHs, in the freely dissolved phase, tend to be more consistently distributed near to potential sources than those in the dissolved phase.