| Abstract: | 本研究的目的是探討台灣居民由攝食魚肉而累積多氯聯苯(Polychlorinated biphenyls,PCBs)個別異構物的曝露量(Exposure)及毒性當量(Toxic equivalent quantity)。過去研究顯示,多氯聯苯普遍存於台灣環境,包括空氣、水、土壤、底泥、及食物等介質中。而攝食魚類是一般民眾最主要的多氯聯苯曝露來源。 多氯聯苯各「個別異構物」(Congener)對人體有不同程度的毒性。故本研究欲由曝露量的最主要來源:魚類著手,分析其中可食用部分的多氯聯苯個別異構物,並以此濃度推估台灣居民由此途徑累積而來之曝露量及毒性當量。 本研究的目標魚種為:吳郭魚、虱目魚、白鯧、白帶及鱈魚。並於台中市的魚市場購買樣本。且以GC-ECD(Gas Chromatograph-Electron Capture Detector)分析18種選定的多氯聯苯個別異構物。 結果顯示,鱈魚中含最多種多氯聯苯個別異構物,且其含量為最高(3.17-24.77ppb),而白鯧、白帶僅含少數且少量之多氯聯苯異構物,吳郭魚與虱目魚的樣本間的變異數較大,有些樣本無任何多氯聯苯,有些含有數種相當濃度之異構物。 攝食鱈魚會累積最多之多氯聯苯,平均而言,每人每年所攝食之PCBs曝露量估計可能約為9.23.mu.g。且會造成最高之毒性當量,平均約為5.99* 10/sup -4/ng/g TEQ。
The objective of this research was to assess the exposure of Taiwan residents to polychlorinated biphenyl congeners (PCBs) from fish consumption. Previous studies indicated that PCBs exist in Taiwan's environment including air, water, soil, sediment, and food. And fish consumption is the major source of general public intake of PCBs. The toxicity of PCBs is strongly related to their structures, different congener has different toxicity to human. This project tried to estimate the potential toxic effects of PCBs in congener-specific basis by assessing the major PCB exposure route to general public: fish consumption. Five fish species were studied, including tilapia, milkfish, hairtail, white pomfret, and cod. Fishes were bought at local markets of Taichung city. Only the edible parts of fishes were analyzed. Analysis was conducted by GC-ECD (Gas Chromatograph-Electron Capture Detector). Totally, 18 congeners have been analyzed and quantified. Results showed that cod samples had the highest PCB concentrations among them (3.17-24.77ppb), they also had more kinds of congeners than any other fishes. Hairtail and white pomfret samples had the lowest concentrations and the least numbers of congeners. There were higher variation among those tilapia and milkfish samples; some of them had no PCB contamination, while others had few. Cod consumption would result in highest exposure and TEQ among those five species. On average, Taiwan residents' would obtain about 9.23.mu.g PCBs from cod consumption every year. And the mean TEQ from cod samples was 5.99*10/sup -4/ng/g TEQ. |
