Dynamics of Dioxins : Distribution and Fate of PCDD/DF in Matsuyama Plain.

多氯二苯并对二恶英(PCDDs)和二苯并呋喃(PCDf)已被发现是当今环境中的普遍存在。这些化合物符合科学和普遍的利益，我国已经出台了一些规定，以减少这些化合物在环境中的释放。然而，据我们所知，目前还没有关于我们环境中PCDDs/PCDF水平和来源的信息。我们在今年展示了其中一项研究结果。本研究的结果是在松山平原的几个池塘中发现了非2378取代的多氯二苯并呋喃在鱼类体内的生物积累。鱼的样本是大口鳕鱼(Midropterus Salmoides)和蓝鳃(Lepomis Macchirus)。这些异构体分为可食用部分和内脏器官。对于多氯二苯并呋喃，在松山平原池塘的所有鱼样中都检测到了几种2378取代和非2378取代的异构体。如果市场上的鱼类中存在各种非2378取代的异构体，人类就会接触到这些化合物。我们建议不仅要对2378取代的异构体进行风险评估，还要对非2378取代的异构体进行风险评估，特别是下一个主要的有毒化合物。目前，我们正在分析两年来从松山平原采集的其他环境样品(土壤、水域、植物和区域)。

The polychlorinated dibenzo-p-dioxins (PCDDs) and dibezofurans (PCDFs) have been found to be ubiquitos in our environment today. They have been in the scientific and general interest for decates, and our country has introduced a few regulations to reduce the release of these compounds in the environment. However, to our knowlege no information is abailable regarding the levels of PCDDs/PCDFs and the sourcese in our environment.We show one of this research results in this year. A result of this study was to find the bioaccumulation of non 2378-substituted PCDFs in fishes in a few ponds in Matsuyama plain. Fish samples are large-mouth bass (Midropterus salmoides) and blue-gill (Lepomis macrochirus). These were divided into the edible parts and internal organs.For the PCDFs, several 2378-substituted and non 2378-substituted isomers were detected in all fish sampls in ponds in Matsuyama plain.In this study, we confirmed that a lot of non 2378-substituted isomers existed in the edible parts of fishes. If various non 2378-substituted isomers exist in the fishes on the market, humen would been exposed to these compounds. We suggest that the risk assesment should be perfirmed for not only 2378-substituted isoners but also non 2378-substituted isomers, in particularly next predominant toxic compounds.Now, we are analyzing other environmental samples (soils, waters, plants and area) which were collected during two years from Matsuyama plain.