Residues And Comparative Research Of Polychlorinated Biphenyls In Surface Sediments From Chukchi Sea And Xinghua Bay, Fujian Provice

Polychlorinated biphenyls (PCBs), as persistent organic pollutants, are of global concern because they exist in the environmental medium widely. In order to determine the contents and compositions of PCBs homologues in surface sediments, two different latitude areas (Chukchi Sea and Xinghua Bay) had been investigated in this study. The possible source identification was accurately analyzed by using principal component analysis (PCA) method. The ecological risk assessment and comparative study also had been studied with the qualitative and quantitative analyses in these two areas. Base on these dates of the survey, the spatial distribution and environmental behavior of PCBs could be further discussed. The main results were summarized as follows:(1)In this study, GC-MS was used for qualitative and quantitative analyses of PCBs.∑PCBs values were ranged from 152.14 to 610.83 pg/g dw with an average of 408.09 pg/g dw, and 23.81 to 37.18 ng/g dw with an average of 27.85 ng/g dw for the surface sediments from Chukchi Sea and Xinghua Bay, respectively. Compared with other oceanic areas around the world,∑PCBs in both the two areas were low.(2)According to the PCA, Tetra-PCBs were the dominant homologue in the surface sediments from Chukchi Sea, and Tetra-PCBs, Penta-PCBs were controlling the composition of the total PCBs in all samples which from Xinghua Bay. The facts that homologue compositions were characterized by mixtures with a respective low chlorination level indicated that both of Global Fractionation Effect and the atmospheric long-range transport might be the most efficient pathway for these pollutants entering into study areas. The positive correlation was testified between Tri-PCBs and total carbon (TOC), but the relationship was weaken when chlorine atomicity increasing in surface sediments from Chukchi Sea.(3) The qualitative and quantitative analyses were used in ecological risk assessment in study areas. It had been found that the concentrations of PCBs detected in surface sediments from Chukchi Sea were too low to cause biological effects, while the PCBs in sediments from Xinghua Bay might result in more then 10% of biological effects with 91% probability. No risk probability could cause more than 50% of biological effects in both areas, but it was still necessary to pay more attention, especially in Xinghua Bay.(4) The comparative study about contents, spatial distribution, compositions and ecological risk of PCBs in surface sediments between two different latitude areas had been discussed. The results demonstrated that the diversity of characters could be observed as latitude changing, clearly.