title: Distribution of PCDDs/PCDFs and Co-PCBs in human maternal blood, cord blood, placenta, milk, and adipose tissue: dioxins showing high toxic equivalency factor accumulate in the placenta.
abstract: To assess levels of dioxin background contamination and transfer of dioxins from mothers to unborn children and infants, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar-polychlorinated biphenyls (Co-PCBs) were measured in human samples from expectant and nursing mothers living in Nara, Japan. The average toxic equivalency quantities (TEQs) of PCDDs/PCDFs and Co-PCBs from circulating maternal blood, cord blood, placenta, milk taken 3-10 d after delivery, milk taken one month after delivery, and adipose tissue were 26 and 9.3, 15 and 2.3, 31 and 1.2, 16 and 5.4, 18 and 8.8, and 16 and 7.7 pg-TEQ/g-fat, respectively. Among the various PCDD/PCDF congeners, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF contributed most heavily to the TEQs of all maternal samples. Among the various Co-PCB congeners, 3,3',4,4',5-PeCB (#126), 2,3,3',4,4',5-HxCB (#156), and 2,3',4,4',5-PeCB (#118) contributed most heavily to the TEQs of all maternal samples. But, the concentrations and relative percentages of congeners differed among the various samples, suggesting that congeners showing high toxic equivalency factor accumulate in the placenta.
authors.affiliation: Department of Bioresource Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro City, Hokkaido, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.forename: Masuo
authors.initials: M
authors.lastname: Nakano
authors.forename: Shiro
authors.initials: S
authors.lastname: Nakano
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry / Q000378:metabolism; D000328:Adult; D001572:Benzofurans / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D004781:Environmental Exposure / Q000032:analysis; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D018445:Infectious Disease Transmission, Vertical; D007564:Japan / Q000453:epidemiology; D018811:Maternal Exposure; D008895:Milk, Human / Q000737:chemistry / Q000378:metabolism; D010920:Placenta / Q000737:chemistry / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D011247:Pregnancy / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins; D006843:Hydrocarbons, Chlorinated; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls