| 摘要: | 戴奧辛與戴奧辛類多氯聯苯具有環境荷爾蒙的特性，被聯合國環境規劃署列為斯德哥爾摩公約中優先管制的持久性有機污染物，對人體的健康深具影響。
本研究針對數種具代表性的事業共25座廠址放流水中戴奧辛及戴奧辛類多氯聯苯含量進行檢測分析。調查結果毒性當量方面戴奧辛/?喃(PCDD/Fs)濃度介於0.067~112 pg WHO-TEQ/L，就毒性當量而言PCDDs 7種同源物當中以1,2,3,7,8-PeCDD為主要貢獻物種，而PCDFs 10種同源物當中則以2,3,4,7,8-PeCDF為主要貢獻物種；另戴奧辛類多氯聯苯(DLPCBs)毒性當量濃度則介於0.003~0.616 pg WHO-TEQ/L，12種同源物當中以PCB#126(3,4,5,3’,4’-PeCB)為主要貢獻物種。顯示在毒性當量方面本研究的PCDD/Fs與DLPBCBs多種同源物當中以低氯數的五氯同源物貢獻度最高。
另在樣品檢測的原始物種濃度方面，PCDD/Fs以高氯數的OCDD、OCDF為優勢物種；DLPCBs則以PCB#118為優勢物種。
就整體樣品而言，當中除了某一醫院放流水之外，其餘樣品測值皆在國內現行的放流水管制標準值以內，並未高於鄰國日本。
本研究中另針對4個工業區污水處理廠同時採集放流水與放流口底泥進行檢測比對，結果顯示放流水戴奧辛同源物與底泥戴奧辛同源物濃度分布極為類似，顯示事業放流水戴奧辛類化合物的總毒性當量不高原因，有可能並非因為受到破壞或分解而是移轉至污泥中。事業廢水排放之前若能有效進行懸浮粒狀物的攔截、沉降、濾除等程序並妥處最終污泥，將可降低排放廢水中的戴奧辛類化合物。
Dioxin-like compounds (DLCs), which include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs), have been listed in the Stockholm Convention on Persistent Organic Pollutants (POPs). PCDD/Fs and DLPCBs are considered as environmental hormones with high toxicity to human health and environment.
In this study, PCDD/Fs and DLPCBs from 25 wastewater facilities were analyzed and characterized. The results indicate that the toxic equivalents of PCDD/Fs released from 25 industrial facilities range from 0.067 to 112 pg WHO-TEQ/L. The compound 1,2,3,7,8- pentachlorodibenzo-p-dioxin was found to contribute the most TEQ among 7 PCDD congeners and 2,3,4,7,8- pentachlorodibenzofuran was of the highest TEQ among 10 PCDF congeners. The toxic equivalent of DLPCBs range from 0.003 to 0.616 pg WHO-TEQ/L. It was found that 3,3’,4,4’,5-pentachlorobiphenyl (PCB#126) is the primary contributor among 12 DLPCB congeners. This result indicates the 5 chlorine substitutes have the greatest contribution to the toxic equivalent of PCDD/Fs. However, octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) is of the highest concentration among chlorinated substituted PCDD/Fs and PCB#118 is of the highest concentration of DLPCBs. Except one medical facility, the overall analytic PCDD/Fs concentrations from 25 facilities are below national effluent discharge standard(10 pg I-TEQ/L).
This study also includes sediment samples collected from 4 industrial effluent discharge sites where liquid samples were also taken. The concentration and distribution of dioxin in the sediments are comparable to the liquid samples, which suggest that it was due to mass transfer, not decomposition or degradation of dioxins in the sediment. However, the DLCs can be effectively reduced by proper precipitation and filtration of suspended solids (SS) before liquid effluent is discharged out of facilities. |
