| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 89 === After the prohibition of polychlorinated biphenyls (PCBs) production and use globally in 1970s, direct emissions to the atmosphere had been greatly reduced. PCBs are persistent organic pollutants (POPs) with long half-lives in various environmental components. Through the transport in the atmosphere, which is an effective transport medium, PCBs can be found around the world.
Wan-Li area, in the southern Tainan, used to be an industrial park of recovering and disposing waste electronics from 1983 to 1992. There were many capacitors in the waste electronics, which were treated by open-burning and digested with strong acids. Pollutants including PCBs were accumulated in the soils and sediments in that area.
Samples from five different phases ( air, water, soil, sediment and fish ) in An-Jen station were analyzed. PCB concentration in the air was 2.59 ng/m3, in the river water was 6.94∼26.3 ng/L, in soils was 23.8 ng/g, in the column was 22.3∼263 ng/g, in the fishes was 91.6∼180 ng/g. It was found that PCBs was moving from the sediment, fishes and soils to the water; and was moving from the water and the soils to air. Air and soil samples were collected simultaneously in nine different sample stations in Wan-Li area. PCB concentration in the air was 1.61~5.07 ng/m3, in soils was 7.34∼796 ng/g. Higher PCBs concentrations in soil appeared in those stations near Er-Jen river. Air-soil fugacity ratio (fA/fS ) varied with different chlorine numbers on biphenyl. PCB concentrations in the air and soils were much lower in 2001 than in 1990. The fugacity ratio approached 1 in 1990, but it was equal to about 0.05 in 2001. This indicates that pollutant source from air has been significantly reduced. According to the trend of the distribution of PCBs between the air and soils between 1990 and 2001, PCB concentrations in soils and the air will slowly be equilibrated in the next five to ten years. If the weight distribution of the PCB congeners in air is the same as the reference material, we estimate that the air TEQ to be 0.27 pg/m3. Comparing this value with those in the literature, it is not significantly high.
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