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Environmental Dispersion and Distribution of Dioxins and DL-PCBs from Agricultural Fields

农田中二恶英和DL-PCBs的环境扩散和分布

基本信息

批准号：
14580551
负责人：
KAWANO Masahide
金额：
$ 2.11万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) are ubiquitous and persistent in the environment and magnify in organisms through the food web. These compounds finally accumulate in humans. It is well known that some of these compounds are extremely toxic to organisms. In Japan, specific congeners and isomers were applied to agricultural fields as herbicides, i.e. pentachlorophenol and 2,4,6-trichiorophenyl 4-nitrophenylether (CNP), contaminated with octachlorinated dibenzo-p-dioxin(OCDD), and 1,3,6,8- and 1,3,7,9-tetrachlorinated dibenzo-p-dioxins(TCDDs), respectively. Consequently, it is necessarily to evaluate their dispersion from agricultural fields and their presence in environmental matrices. PCDD/DFs in soils of agricultural fields were entered into river through run off caused by rice farming. It is estimated that PCDD/DFs mainly presented in soil particles less than 5μm diameter. Then PCDD/DFs that adsorbed on … More the soil particles deposited to river and coastal bottom sediments. To evaluate dioxin contamination in vegetable, congener analyses of PCDD/DFs and DL-PCBs were performed on three kinds of vegetables (43 individuals). The total dioxin concentrations and toxic equivalent quantity (TEQ) levels in samples ranged from 0.19 to 16 pg/g wet weight and 0.002 to 0.071 pg TEQ/g wet weight, respectively. 1,3,6,8- and 1,3,7,9-TCDDs were main contributors of total dioxin concentrations detected in the vegetable samples. It imply that vegetables must be contaminated by these compounds in agricultural fields during growing. A relatively high concentration of dioxins was found in cucumber samples. The analytical results of PCDD/DFs and DL-PCBs in freshwater and coastal fishes show that these compounds detected in all samples investigated. Impurities of CNP and PCP as herbicides for paddy field were thought as PCDD/DFs sources of fish samples. Whereas Japanese fish samples, 1,3,6,8- and 1,3,7,9-TCDDs and OCDD levels in Chinese fish samples were not so high as the Japanese samples. Dioxins and DL-PCBs in ten species of wild birds collected from Japan were analyzed. The results revealed that the concentrations and homologue / isomer profiles were species-specific, featuring with their unique habitats and feeding habits. It seems to be that the impurities of pesticides such as 1,3,6,8- and 1,3,7,9-TCDDs could be degraded in the birds although intake through their foods such as fish. Japanese human blood samples collected from differently-aged individuals have been analyzed for PCDD/DFs and DL-PCBs. The concentration ranges of PCDDs, PCDFs and DL-PCBs were 58-930, 7.4-37 and 3,100-23,000pg/g, respectively, on a lipid weight basis. TEQ levels were calculated to be 7.0-46pg/g on a lipid weight basis. The levels of 1,3,6,8- and 1,3,7,9-TCDDs in human blood samples were less than detection limit. Statistical analysis indicated a correlation between an increased total TEQ level and increased age. TEQ level of a person aged 60 years is about twice times higher than a person aged 20 years. By these results it is able to make sense out of what had appeared the distributable properties of dioxins which were ever applied as impurities of herbicides to agricultural fields. Less

多氯二苯并对二恶英和二苯并呋喃（PCDD/DFs）和二恶英类多氯联苯（DL-PCBs）在环境中普遍存在并具有持久性，并通过食物网在生物体中放大。这些化合物最终在人体内积累。众所周知，这些化合物中的一些对生物体具有极强的毒性。在日本，特定的同系物和异构体被用作农田除草剂，即五氯苯酚和2，4，6-三氯苯基4-硝基苯基醚，分别受到八氯二苯并对二恶英（OCDD）和1，3，6，8-和1，3，7，9-四氯二苯并对二恶英（TCDD）的污染。因此，有必要评估它们在农田中的扩散情况及其在环境基质中的存在。农田土壤中的PCDD/DFs主要通过稻田径流进入河流。估计PCDD/DFs主要存在于直径小于5μm的土壤颗粒中。然后是吸附在 ...更多信息土壤颗粒沉积到河流和海岸的底部沉积物中。为评价蔬菜中二恶英的污染状况，对3种蔬菜（43个个体）进行了二恶英（PCDD/DFs）和DL-PCBs的同源物分析。样本中的二恶英总浓度和毒性当量水平分别为0.19至16皮克/克湿重和0.002至0.071皮克毒性当量/克湿重。1，3，6，8-和1，3，7，9-TCDDs是蔬菜样品中二恶英总浓度的主要贡献者。这意味着蔬菜在生长过程中一定受到这些化合物的污染。在黄瓜样本中发现了相对较高浓度的二恶英。结果表明，淡水鱼和近海鱼类中PCDD/DFs和DL-PCBs的检出率均为100%。稻田除草剂CNP和PCP的杂质被认为是鱼样品中PCDD/DFs的来源。而日本鱼样品中1，3，6，8-和1，3，7，9-TCDD和OCDD含量均低于日本鱼样品。分析了从日本采集的10种野生鸟类体内的二恶英和DL-PCBs。结果表明，该物种的浓度和同系物/异构体分布具有物种特异性，具有独特的生境和食性。1，3，6，8-和1，3，7，9-TCDDs等农药的杂质虽然通过鱼类等食物摄入，但在鸟类体内可能发生降解。对从不同年龄的日本人身上采集的血样进行了多氯二苯并对二恶英/二苯并呋喃和DL-多氯联苯分析。以脂质重量计，PCDDs、PCDFs和DL-PCBs的浓度范围分别为58-930、7.4-37和3，100 -23，000 pg/g。根据脂质重量计算，TEQ水平为7.0- 46 pg/g。人血中1，3，6，8-和1，3，7，9-TCDDs的含量均低于检测限。统计分析表明，增加总TEQ水平和年龄增加之间的相关性。60岁的人的TEQ水平大约是20岁的人的两倍。通过这些结果，它是能够有意义的出现二恶英的分布特性，曾经作为除草剂的杂质应用到农业领域。少