title: Temporal trends and sources of PCDD/Fs, pentachlorophenol and chlornitrofen in paddy field soils along the Yoneshiro River basin, Japan.
abstract: In order to understand the long-term behaviors of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), pentachlorophenol (PCP), and 2,4,6-trichlorophenyl-4'-nitrophenyl ether (chlornitrofen, CNP) in paddy soil, we measured their concentrations in paddy soil samples collected in 1982 and 1984 (1980s) and in 2000 and 2002 (2000s) from the Yoneshiro River basin, Japan. The concentrations of PCP and CNP decreased from the 1980s to the 2000s, whereas the concentrations of PCDD/Fs and their toxic equivalency (WHO2006-TEQ) remained. The major sources of PCDD/Fs in the paddy soil samples were attributed to impurities in PCP and CNP as a result of comparisons of homologue and congener profiles and principal component analysis. Based on the results of comparison of total input and remaining amount, it is estimated that more than 99% of PCP and CNP applied to the paddy fields had disappeared, whereas most of the applied PCDD/Fs and TEQ remained.
authors.affiliation: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. kobayashi.jun@nies.go.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Mizuki
authors.initials: M
authors.lastname: Sakai
authors.forename: Hideo
authors.initials: H
authors.lastname: Kajihara
authors.forename: Yukio
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D000383:Agriculture; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring / Q000379:methods; D007564:Japan; D010416:Pentachlorophenol / Q000032:analysis*; D010647:Phenyl Ethers / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013997:Time Factors; D018505:Waste Management; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D010647:Phenyl Ethers; D000072317:Polychlorinated Dibenzodioxins; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; C010422:2,4,6-trichlorophenyl 4-nitrophenyl ether; D010416:Pentachlorophenol