title: Correlation between human maternal-fetal placental transfer and molecular weight of PCB and dioxin congeners/isomers.
abstract: Establishing methods for the assessment of fetal exposure to chemicals is important for the prevention or prediction of the child's future disease risk. In the present study, we aimed to determine the influence of molecular weight on the likelihood of chemical transfer from mother to fetus via the placenta. The correlation between molecular weight and placental transfer rates of congeners/isomers of polychlorinated biphenyls (PCBs) and dioxins was examined. Twenty-nine sample sets of maternal blood, umbilical cord, and umbilical cord blood were used to measure PCB concentration, and 41 sample sets were used to analyze dioxins. Placental transfer rates were calculated using the concentrations of PCBs, dioxins, and their congeners/isomers within these sample sets. Transfer rate correlated negatively with molecular weight for PCB congeners, normalized using wet and lipid weights. The transfer rates of PCB or dioxin congeners differed from those of total PCBs or dioxins. The transfer rate for dioxin congeners did not always correlate significantly with molecular weight, perhaps because of the small sample size or other factors. Further improvement of the analytical methods for dioxin congeners is required. The findings of the present study suggested that PCBs, dioxins, or their congeners with lower molecular weights are more likely to be transferred from mother to fetus via the placenta. Consideration of chemical molecular weight and transfer rate could therefore contribute to the assessment of fetal exposure.
authors.affiliation: Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; Center for Preventive Medical Sciences, Chiba University, Chiba 260-8670, Japan. Electronic address: cmori@faculty.chiba-u.jp.
authors.forename: Chisato
authors.initials: C
authors.lastname: Mori
authors.affiliation: Department of Pharmacology, Physiology and Toxicology, BBSC, Marshall University, Huntington, WV 25755, USA.
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakamura
authors.affiliation: Center for Preventive Medical Sciences, Chiba University, Chiba 260-8670, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Todaka
authors.affiliation: Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
authors.forename: Takeyoshi
authors.initials: T
authors.lastname: Fujisaki
authors.affiliation: Center for Preventive Medical Sciences, Chiba University, Chiba 260-8670, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Matsuno
authors.affiliation: Center for Preventive Medical Sciences, Chiba University, Chiba 260-8670, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nakaoka
authors.affiliation: Center for Preventive Medical Sciences, Chiba University, Chiba 260-8670, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Hanazato
mesh_terms: D000293:Adolescent; D000328:Adult; D004147:Dioxins / Q000032:analysis / Q000097:blood* / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D006801:Humans; D007536:Isomerism; D008431:Maternal-Fetal Exchange; D008970:Molecular Weight; D009035:Mothers; D010920:Placenta / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000097:blood* / Q000378:metabolism*; D011247:Pregnancy; D014470:Umbilical Cord / Q000378:metabolism; D055815:Young Adult
chemical_list: D004147:Dioxins; D011078:Polychlorinated Biphenyls
keywords: Dioxins; Humans; Placental transfer rate; Polychlorinated biphenyls