Abstract
Fish and shellfish were collected from local supermarket and coastal area of Dalian, local supermarkets of Qingdao, Yantai, Tianjin and Zhuanghe surrounding polluted Bohai Sea in China and analyzed for the concentrations of PCDDs, PCDFs and Co-PCBs. Average concentrations of PCDDs, PCDFs and Co-PCBs in fish samples were 0.192, 0.357 and 368 pg/g on wet weight basis, respectively. Average value of total TEQ obtained from the analysis of fish samples was 0.340 pg-TEQ/g on wet weight basis which is lower compared to fish samples collected from coastal area of Japan. In the case of shellfish samples, average value of total TEQ in the samples collected from Dalian, Qingdao, Yantai, Tianjin and Zhuanghe was 0.149, 0.126, 0.124, 0.116 and 0.032 pg-TEQ/g on wet weight basis, respectively. These values of TEQ seem to be similar to those in shellfish samples collected from coastal areas of Japan.
The residue profiles of PCDFs in shellfish were different from those in fish. Compared to 2, 3, 7, 8-PCDFs, more non-2, 3, 7, 8-PCDFs were metabolized by fish. In addition, in fish and shellfish samples analyzed in this study, higher contributors to TEQ value of PCDDs were 2, 3, 7, 8-TeCDD and 1, 2, 3, 7, 8-PeCDD, higher contributors to TEQ value of PCDFs were 2, 3, 7, 8-TeCDF and 2, 3, 4, 7, 8-PeCDF Furthermore, IUPAC # 126 PCB was the highest contributor to TEQ value of Co-PCBs among all congeners of Co-PCBs determined.
According to profiles of individual isomers of PCDD/DFs detected in shellfish samples, it could be considered that incineration is the main sources of PCDD/DFs. Alike, it could be considered that use and leaching of commercial PCB products (# 1PCB and # 2PCB made by China, equivalent to KC-300 and KC-500, respectively) were the main sources of Co-PCBs.
