Kiguchi Osamu, Kobayashi Takashi, Wada Yoshihisa, Saitoh Katsumi, Ogawa Nobuaki
Faculty of Engineering and Resource Science, Akita University, Akita 010-8502, Japan.
Chemosphere. 2007 Mar;67(3):557-73. doi: 10.1016/j.chemosphere.2006.09.044. Epub 2006 Nov 13.
Paddy soils and sediments from the Yoneshirogawa, Omonogawa, and Koyoshigawa River Basins in Akita were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The levels and compositions in those samples including soils from non-agricultural areas (non-agricultural soils) were investigated using isomer-specific analysis to determine characteristic sources. The PCDD/PCDF compositions in the samples were compared with respect to possible sources. The PCDD/PCDF concentrations in paddy soils were much higher than those in the non-agricultural soils and much higher than those found in other parts of Japan. Although PCDD/PCDFs were ubiquitous in sediments from river sources to mouths of the respective river basins, those concentrations were much lower than those from paddy soils and non-agricultural soils, and from other parts of Japan. Comparison of PCDD/PCDF homologues and isomer compositions for samples indicated that compositions of paddy soils and sediments, except for those from river sources, had similar characteristics to PCDD/PCDFs originating from impurities in herbicides, 2,4,6-trichlorophenyl 4-nitrophenyl ether (CNP) and pentachlorophenol (PCP), and that compositions of river-source sediments and non-agricultural soils resembled those of atmospheric depositions. Results of statistical analyses suggest that PCDD/PCDF contamination of paddy soils and sediments is attributable mainly to three sources: CNP, PCP, and atmospheric deposition. Results of this study also demonstrate that CNP and PCP are not only important contaminants of local areas of Japan, but that they exist throughout Akita, in northern Japan. We therefore conclude that PCDD/PCDF pollution caused by those compounds has a widespread influence on paddy soils and river sediments in Japan.
对秋田县米代川、雄物川和小义川流域的稻田土壤及沉积物中的多氯代二苯并 - 对 - 二噁英（PCDDs）和二苯并呋喃（PCDFs）进行了分析。利用异构体特异性分析研究了包括非农业区土壤（非农业土壤）在内的那些样品中的含量及组成，以确定其特征来源。将样品中的PCDD/PCDF组成与可能的来源进行了比较。稻田土壤中的PCDD/PCDF浓度远高于非农业土壤中的浓度，也远高于日本其他地区的浓度。尽管PCDD/PCDF在各流域从河源到河口的沉积物中普遍存在，但这些浓度远低于稻田土壤、非农业土壤以及日本其他地区的浓度。对样品的PCDD/PCDF同系物和异构体组成进行比较表明，除河源沉积物外，稻田土壤和沉积物的组成与源自除草剂2,4,6 - 三氯苯基4 -硝基苯基醚（CNP）和五氯苯酚（PCP）中杂质的PCDD/PCDF具有相似特征，而河源沉积物和非农业土壤的组成与大气沉降物的组成相似。统计分析结果表明，稻田土壤和沉积物中PCDD/PCDF污染主要归因于三个来源：CNP、PCP和大气沉降。本研究结果还表明，CNP和PCP不仅是日本局部地区的重要污染物，而且在日本北部的秋田县各地均有存在。因此，我们得出结论，这些化合物造成的PCDD/PCDF污染对日本的稻田土壤和河流沉积物具有广泛影响。
