在一般水體環境中常可發現的化學物質，除傳統的指標污染物外，近年也增加了讓釵h學者與環保人士相當關注的仿雌激素物質或環境荷爾蒙。多數的環境荷爾蒙具有環境與生物累積性，而一般的環境採樣方式無法實際反映出此類物質的環境特性。本實驗主要探討高屏溪水域中壬基苯酚 (NP, Nonylphenol) 污染情況與生物效應之關連性。採用模擬環境狀態之被動式採樣器--半滲透膜裝置 (SPMD,semi-permeable membrane devices) 以長時間、累積的方式進行環境採樣監測，再對所採集的樣本進行化學分析，並以生物試驗探究其採集後萃取物之生物效應，探討水中化學物質與生物效應之關係。
本研究選用青魚將魚（Oryzias latipes, Japanese medaka）為指標生物，將 SPMD 萃取液注射於魚腹內，經暴露一星期後再使用斷尾法取其血清，並使用自動電泳系統 Experion Pro260分析其被誘導之魚體卵黃蛋白前質 ( vitellogenin,VTG) 的含量及誘導率。本研究結果顯示：(1)高屏溪流域之壬基苯酚經化學分析後其時量平均濃度均超過 NP 誘導 VTG 閾值10 μg/L。(2)本實驗 SPMD 所吸附 NP 濃縮倍數高達 2500-3000 倍，証明其的確可模擬魚體於水環境中吸附污染物質之作用。(3) 由本研究監測數據得知，SPMD應用於台灣河川的暴露時間不宜太長。(4) 5月份高屏溪下游為實驗組中 VTG 誘導率最高者，其佔總蛋白質之 0.212 %，相當於對照組雄青鱂魚體內背景VTG含量的 35.33 倍。(5) 活體實驗發現VTG誘導率與本實驗注射SPMD萃取液中的 NP 濃度顯示無明顯正相關性，必須綜合所有可能導致 VTG 誘導或抑制的因素之後才能做判斷。
本研究結果顯示 SPMD 技術之適用性。台灣河川污染嚴重，應可運用可被 SPMD 吸附或是對生物產生雌激素誘導的汙染物進行檢測，並進一步進行生物評估及生物指標與化學檢測結果之相關性分析。 Most hazardous chemicals usually were found in aquatic environment, including traditional indicative pollutants, xenoestrogen and environmental hormones. Most of environmental hormones reveal the acute toxicity and biological accumulation in environment. Its environmental characteristics could not be revealed by traditional sampling method.
In this study, the passive sampling technology, semi-permeable membrane devices (SPMD) was applied to collect water samples from Kao-Ping River Basin for chemical analysis and bioassays to investigate the relationship between of nonyphenol pollutant and biological effects. Moreover, vitellogenin (biochemical endpoint) was used as the biomarker for observation of entocrine disruptor endpoints.
Japanese medaka was selected as the indicative specie in this study. Fish were injected intraperitoneally with SPMD extracts, and were sacrificed after a total of 7-day exposure to the extracts. Plasma were immediately removed from each fish and maintained frozen at 80°C until biochemistry analysis. Estrogenic responses and inductivity were evaluated based on the expression of serum vitellogenin (VTG) using Experion Pro260 electrophoresis system.
The results indicated that (1) the time-weighted average conentrations of NP in Kao-Ping River Basin were over 10 μg/L NP inductivity VTG threshold limited value,(2) The NP accumulation times higher than NP in water sample by SPMD was up to 2500-3000. These results reveal that SPMD could serve as a good surrogate for fish to simulate accumulations of NP, and may be used as a universal surrogate for fish in natural waters. (3) According to the monitoring data, the expeosurs period of SPMD should not be too long when it was applied in aguatic environment in Taiwan. (4) The highest VTG induction rate was 0.212% for the extracts of river samples collected from the upper stream of Kao-Ping River in May, and this VTG induction rate was equal to 35.33-fold compared with SPMD blank. (5) There was no significantly positive relationship between VTG induction rates detected in vivo for this experiment and the concentrations of NP in SPMD extracts. The relationship between VTG induction rate and concentration of NP should be discussed and concluded with overall considering the possibilities of the factor to enhance or suppress the VTG induction rate.
The preliminary results demonstrated that SPMD approach is appropriate to the environmental water samples. Moreover, contaminants that could be adsorbed by the SPMD membranes or could induce estrogenic effect to organisms in the environment should be determined with SPMD method widely in the future. The biological evaluation, biotic index and chemical analysis of environmental samples will be performed advancedly to estimate the applicability and feasibility of this system.
