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全國持久性有機污染物大氣沈降特性及湖泊底泥歷史變動趨勢研究(2/3)

中文摘要 本研究針對日月潭大氣戴奧辛沈降量、湖泊底泥及湖泊水體進行量測,以建立戴奧辛於環境受體之累積、轉化速率與沈降量之關聯性。研究結果顯示日月潭地區大氣戴奧辛沈降通量於2009年4月最高達1.88至2.95 pg-I-TEQ/m2-day。大氣乾濕沈降觀測結果與傳統落塵之分析結果顯示,相同的採樣地點大氣乾濕沈降自動採樣器採樣所得之戴奧辛沈降通量(1.19至3.43 pg-I-TEQ/m2-day)皆略大於以傳統落塵桶所獲致之結果(0.978至2.95 pg-I-TEQ/m2-day)。由於雨滴可將不同粒徑之粒狀物帶至地面,故大氣中戴奧辛濕沈降通量(17.3至471 pg-I-TEQ/m2-雨天)明顯高於乾沈降(0.379至2.55 pg-I-TEQ/m2-晴天)。另外,在底泥泥芯戴奧辛含量歷年變動趨勢方面,日月潭南灣(1.64至4.78 ng-I-TEQ/kg d.w.)之泥芯樣品戴奧辛濃度明顯高於日月潭出水口(0.917至2.89 ng-I-TEQ/kg d.w.)及日月潭中心點(0.092至1.91 ng-I-TEQ/kg d.w.)之採樣結果,日月潭南灣泥芯樣品戴奧辛濃度於深度14-16公分處開始增加並於深度12-14公分處達最高(4.78 ng-I-TEQ/kg d.w.),同位素樣品分析結果顯示其所對應之歷史年代為1973年,推估該時期農民大量使用農藥化學品導致戴奧辛進入日月潭累積。國內主管機關依農藥管理法開始將DDT禁用於農藥後(1973年),日月潭底泥中戴奧辛濃度開始呈現下降趨勢,但隨者國內五氯酚(PCP)及三氯酚(CNP)使用量提高(1975至1985年),導致1985至1991日月潭沉積底泥中戴奧辛濃度未能呈現持續下降趨勢。
中文關鍵字 戴奧辛, 持久性有機污染物, 大氣沈降, 岩芯

基本資訊

專案計畫編號 EPA-98-E3S4-02-05 經費年度 098 計畫經費 1662 千元
專案開始日期 2009/01/22 專案結束日期 2009/12/31 專案主持人 紀凱獻
主辦單位 環檢所 承辦人 李慈毅 執行單位 中央研究院

成果下載

類型 檔名 檔案大小 說明
期末報告 期末報告定稿 _NIEA格式_.pdf 5MB

Evaluation of Atmospheric PCDD/F Dry/wet Deposition and Historical Trends of PCDD/Fs in Sediments Buried in a Reservoir in Central Taiwan (2/3)

英文摘要 In this study, PCDD/F deposition was measured at Sun Moon Lake via automated PCDD/F ambient air precipitation sampler and traditional cylindrical vessels from January 2009 to December 2009. Significantly higher atmospheric PCDD/F deposion flux (1.88 to 2.95 pg-I-TEQ/m2-day) were measured at this area in April 2009. Additionally, the sampling results also indicate that the PCDD/F deposition fluxes measured with the automated PCDD/F precipitation sampler (1.32 to 3.43 pg-I-TEQ/m2-day) are higher than that sampled with cylindrical vessels (0.978 to 2.95 pg-I-TEQ/m2-day). That is attributed to the fact that part of PCDD/Fs collected by traditional cylindrical vessels are photodegraded. Furthermore, the wet deposition flux of PCDD/Fs (17.3 to 471 pg-I-TEQ/m2-rainy day) observed in this study is significantly higher than dry deposition flux (0.379 to 2.55 pg-I-TEQ/m2-sunny day). This study also reports vertical profiles of a wide variety of PCDD/F in a sediment core, collected from different locations of Sun Moon Lake. The PCDD/F contents in sediment cores measured at Southern bay (1.64 ~ 4.78 ng-I-TEQ/kg d.w.) of Sun Moon Lake quite higher than those measured at outlet (0.917 ~ 2.89 ng-I-TEQ/kg d.w.) and central (0.092 ~ 1.91 ng-I-TEQ/kg d.w.) of Sun Moon Lake. Our results also demonstrated that PCDD/F concentrations in the sediment core at Southern bay started to increase at a depth of 14-16 cm and reached the peak (4.78 ng-I-TEQ/kg d.w.) at 12-14 cm. Based on the results of isotope analysis in sediment core collected in Sun Moon Lake, the estimated year of the sediment core at the depth of 12-14 cm is 1973. In 1973, the Taiwan government proposed the regulation of DDT use in 1973. In addition, the variation of PCDD/F contents in different depth of sediment core is similar to that of the pesticides (PCP and CNP) production in Taiwan. The previous report indicated that higher productions of PCP and CNP were observed in 1975 and 1986, respectively. Therefore, the PCDD/F contents in the sediment cores at depth 6-10 cm (estimated age: 1985 to 1991) did not decrease significantly.
英文關鍵字 Dioxin, POP, deposition, core