title: Mass balance and long-term fate of PCDD/Fs in a lagoon sediment and paddy soil, Niigata, Japan.
abstract: Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in a sediment core and in samples of surface sediment and paddy soil collected from the Toyano lagoon and Kameda basin in Niigata, Japan, were analyzed to elucidate the temporal trends of their concentrations in the lagoon sediment and the relationship between the sediment and the paddy soil. The mass balance of these pollutants was also estimated to determine their long-term fate in surface waters. An analysis by chemical mass balance identified the agrochemicals pentachlorophenol and 2,4,6-trichlorophenyl 4-nitrophenyl ether as the major sources of PCDD/Fs. On the basis of the findings regarding the mass balance in the Kameda basin over the last 40 years, we estimate that more than half the input of PCDD/Fs to the Kameda basin has disappeared. We suggest that the PCDD/Fs that flowed out from the paddy fields have been transferred to the lower basin.
authors.affiliation: National Institute for Agro-Environmental Science, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan. mizukis@affrc.go.jp
authors.forename: Mizuki
authors.initials: M
authors.lastname: Sakai
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Seike
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Hideo
authors.initials: H
authors.lastname: Kajihara
authors.forename: Yukio
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D001572:Benzofurans / Q000032:analysis*; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring / Q000379:methods; D005506:Food Contamination; D019015:Geologic Sediments / Q000032:analysis*; D006540:Herbicides / Q000032:analysis*; D006801:Humans; D007564:Japan; D012275:Oryza; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D006540:Herbicides; D000072317:Polychlorinated Dibenzodioxins; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical