| 摘要: | 湖泊、河川和海洋之底泥一般可視為持久性有機汙染物在環境中之最終的儲存場，因此持久性有機汙染物於水體、懸浮微粒、底泥及生物體之個別濃度變化趨勢將可呈現該區域之污染特性。其中，底泥在環境介質中扮演著污染事件紀錄的角色，故藉由汙染物於底泥中之濃度了解其地區受汙染的程度及歷史變化趨勢。本研究利用鑽取式採樣器(Core sampler)收集翡翠水庫及日月潭之深層底泥，研究結果顯示翡翠水庫底泥岩芯樣品中戴奧辛類化合物毒性當量濃度為0.750~2.81 pg-WHO-TEQ/g d.w.。日月潭底泥岩芯樣品中戴奧辛類化合物毒性當量濃度為0.111~1.39 pg-WHO-TEQ/g d.w.。翡翠水庫底泥中PCDDs與PCDFs比值為24.6~190，日月潭底泥中PCDDs與PCDFs比值為7.02~183。在物種分布方面，翡翠水庫底泥岩芯中OCDD分布百分比界於91至98%，日月潭底泥岩芯中OCDD所佔比例介於81%至98%，比較其結果日月潭OCDD所佔比例變動性較翡翠水庫大，日月潭底泥岩芯OCDD毒性當量濃度於深度28-30公分開始逐漸上升至表層，初步推論該歷史年代大量OCDD物質進入日月潭。多氯聯苯於兩湖泊底泥岩芯中主要優勢物種皆為PCB-118、PCB-105及PCB-77。翡翠水庫底泥中有機氯農藥含量顯示主要物種為DDTs、Chlordane、Dieldrin及HCB，其中DDTs含量最高，濃度變化為7.54×102至4.37×103 pg/g d.w.，Chlordane、Dieldrin及Hexachlorobenzene (HCB)濃度變化分別為5.55×102至8.54×102 pg/g d.w.、 3.05×102至9.71×102 pg/g d.w.、1.40×102至4.91×102 pg/g d.w.。日月潭底泥中有機氯農藥含量顯示主要物種為DDTs、Chlordane、Dieldrin及HCB，其中DDTs含量最高，濃度變化為5.44×102至1.38×103 pg/g d.w.，Chlordane、Dieldrin及Hexachlorobenzene (HCB)濃度變化分別為5.01×102至1.11×103 pg/g d.w.、 2.83×102至6.74×103 pg/g d.w.、1.11×102至4.55×103 pg/g d.w.。 Persistent organic pollutants, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (co-PCBs), DDTs, Chlordane, aldrin, Dieldrin, endrin, heptachlor and Hexachlorobenzene were determined in sediment core samples from the Feitsui Reservoir and the Sun Moon Lake. The total concentration of dioxins and their toxic equivalent quantity (TEQ; calculated with the WHO 2005 Toxic Equivalency Factors) value ranged from 0.750 to 2.81 pg-WHO-TEQ/g d.w.( Feitsui Reservoir) and 0.111 to 1.39 pg-WHO-TEQ/g d.w.( Sun Moon Lake) in the sediment. Based on toxic equivalent quantity analysis, OCDD showed a gradual increase from 28-30 cm toward the surface, indicating that the pollution source at that period might be more influenced by PCP and CNP. Profiles of the concentration and composition of PCDDs and PCDFs congeners in all sediment layers were predominated by higher chlorinated PCDDs, in particular OCDD which contributed more than 90% to the total PCDD/DFs concentration in the Feitsui Reservoir and the Sun Moon Lake. The PCDDs/DFs-derived TEQ contributed more than 90% of ΣTEQ (PCDDs/DFs and co-PCBs) in all the sediment layers detected. PCB-118 is the most dominant congener in all detectable samples, followed by PCB-105 and PCB-77. The overall concentration of DDTs, Chlordane, Dieldrin and Hexachlorobenzene ranged from 7.54×102 - 4.37×103 pg/g d.w., 5.55×102 - 8.54×102 pg/g d.w., 3.05×102 - 9.71×102 pg/g d.w., 1.40×102-4.91×102 pg/g d.w. in the sediment from the Feitsui Reservoir. The overall concentration of DDTs, Chlordane, Dieldrin and Hexachlorobenzene ranged from 5.44×102 - 1.38×103 pg/g d.w., 5.01×102 - 1.11×103 pg/g d.w., 2.83×102 - 6.74×103 pg/g d.w., 1.11×102 - 4.55×103 pg/g d.w. in the sediment from the Sun Moon Lake. |
