Background: Hydroxylated polychlorinated biphenyls (OH-PCBs), unlike PCBs, are in general readily excreted yet are still detected in humans and animals. Active transport of OH-PCBs across the ...placenta and hydroxylation of PCBs by the fetus suggest the potential for greater impact on the fetus compared with the parent PCB compounds, but little is known about their health effects, particularly in humans. Objectives: The objective of this study was to evaluate the associations between prenatal OH-PCB exposure and neurodevelopment in children at 16 months of age in eastern Slovakia. Methods: A birth cohort (n = 1,134) was enrolled during 2002-2004. We analyzed six OH-PCB metabolites (4-OH-CB-107, 3-OH-CB-153, 4-OH-CB-146, 3-OH-CB-138, 4-OH-CB-187, and 4-OH-CB-172) in a subset of the cohort. The Bayley Scales of Infant Development were administered to the children at the 16-month follow-up visit. We developed multiple linear regression models predicting standardized scores for the Mental Development Index (MDI) and Psychomotor Development Index (PDI) from maternal (n = 147) and cord (n = 80) serum OH-PCB concentrations, adjusting for sex of child, district, HOME (Home Observation for Measurement of the Environment) score, and maternal score on Raven's Progressive Matrices. Results: Cord 4-OH-CB-107 was significantly associated with lower MDI (ß = -2.27; p = 0.01) and PDI (ß = -4.50; p = 0.004). Also, maternal 4-OH-CB-107 was significantly associated with lower MDI (ß = -1.76; p = 0.03) but not PDI. No other OH-PCB metabolites were associated with decreased PDI or MDI. Conclusions: Our findings showed a significant association of 4-OH-CB-107 with decreased MDI, which can possibly be mediated by endocrine disruption, altered neurotransmitter functions, or reduced thyroid hormone concentrations in brain.
Objective: Our aim in the present study was to characterize and quantify the levels of polychlorinated biphenyls (PCBs) and specific polychlorobiphenylol (OH-PCB) metabolites in maternal sera from ...women delivering in eastern Slovakia. Design: During 2002-2004, blood samples were collected from women delivering in two Slovak locations: Michalovce district, where PCBs were formerly manufactured, and Svidnik and Stropkov districts, about 70 km north. Participants: A total of 762 and 341 pregnant women were sampled from Michalovce and Svidnik/Stropkov, respectively, and OH-PCBs were measured in 131 and 31. Evaluation/Measurements: We analyzed PCBs using gas chromatography (GC)/electron capture detection. OH-PCBs and pentachlorophenol (PCP) were determined as methyl derivatives using GC-electron capture negative ionization/mass spectrometry. We characterized distributions in the full cohort using inverse sampling weights. Results: The concentrations of both PCBs and OH-PCB metabolites of Michalovce mothers were about two times higher than those of the Svidnik/Stropkov mothers (p < 0.001). The median weighted maternal serum levels of the sum of PCBs (2PCBs) were 5.73 ng/g wet weight (Michalovce) and 2.82 ng/g wet weight (Svidnik/Stropkov). The median sum of OH-PCBs (ΣOH-PCBs) was 0.55 ng/g wet weight in Michalovce mothers and 0.32 ng/g wet weight in Svidnik/Stropkov mothers. 4-OH-2,2',3,4',5,5',6-Heptachlorobiphenyl (4-OH-CB187) was a primary metabolite, followed by 4-OH-2,2',3,4',5,5 '-hexachlorobiphenyl (4-OH-CB146). Only four PCB congeners-CBs 153, 138, 180, and 170-had higher concentrations than 4-OH-CB187 and 4-OH-CB146 (p < 0.001). The median ratio of the ΣOH-PCBs to the ΣPCBs was 0.10. Conclusions: Mothers residing in eastern Slovakia are still highly exposed to PCBs, and their body burdens of these pollutants and OH-PCB metabolites may pose a risk for adverse effects on health for themselves and their children.
Humans, independent on where they live, are exposed to complex and various mixtures of chemicals, including persistent organic pollutants (POPs). The variability of the exposure depends on sources of ...the chemicals and is influenced by e.g. geography, social and cultural heritage. While exposures to POPs are frequently studied in populations from developed industrial countries, very little is known on levels and trends of POPs in developing countries, especially in Africa.
The aim of the present study was to investigate levels and temporal trends of POPs in adults from Guinea-Bissau.
Serum samples were obtained from an open cohort of police officers in Guinea-Bissau. Repeated samples from 33 individuals were obtained at five time points between 1990 and 2007, in all 147 samples. Pooled serum samples were extracted and cleaned-up prior to analysis by gas chromatography and mass spectrometry. The concentration of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4′-DDT) and its metabolites, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexachlorocyclohexanes (HCHs) were determined.
The major POP found in all samples was 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (4,4′-DDE) followed by 4,4′-DDT. 4,4′-DDE, 4,4′-DDT, PCBs and β- and γ-HCH were significantly decreasing over time. The PBDEs were found at low concentrations, with an increasing temporal trend for BDE-153.
National and international management may be behind the observed decreased organohalogen compound concentrations in humans from Guinea-Bissau from the early 1990's and onwards, similarly to the development of these compounds in humans from industrial countries. In contrast, PBDEs follow a trend of increasing concentrations even though at low levels.
Polychlorinated biphenyls (PCBs) were commercially produced between 1959 and 1984 in eastern Slovakia. Improper handling led to a highly contaminated local environment and high levels of PCBs in ...humans and wildlife in the Michalovce area. The aim of this study was to analyse serum for methylsulfonyl metabolites of PCB (MeSO
2-PCBs) and DDE (3-MeSO
2-DDE) in serum samples from pregnant women and in a selected number of paired cord blood samples to assess maternal sulfone levels and patterns, and transplacental transfer of these metabolites. The donating women were from two districts in eastern Slovakia. A liquid–liquid extraction method together with separation of substance groups and further clean-up on silica gel columns were applied prior to analysis by gas chromatography/mass spectrometry. 3-MeSO
2-DDE was the major methyl sulfone in most of the samples followed by a yet not identified MeSO
2-hexaCB, 4′-MeSO
2-CB101, 4′-MeSO
2-CB87 and 4-MeSO
2-CB149. The women from the contaminated area had three times higher concentrations of the MeSO
2-PCBs than women from the reference area. This is the first report on methyl sulfone metabolites of PCB and DDE in human cord serum. It is shown that these metabolites are transported through the placenta. The levels of MeSO
2-PCBs in the maternal serum were about 1.5 times higher than in the corresponding cord serum on a lipid weight basis. For 3-MeSO
2-DDE, the levels were about the same in maternal and cord serum. The difference in the maternal:cord ratio, comparing MeSO
2-PCBs with 3-MeSO
2-DDE might be due to differences in transport through the placenta caused by their different affinities for lipoproteins and plasma proteins.
The aim of this study was to assess persistent organochlorine pollutant (POP) levels in serum collected from children (11–15 years old) working and sometimes also living at the municipal ...waste-disposal site in Managua, located at the shore of Lake Managua, and in nonworking children living both nearby and also far away from the waste-disposal site. The influence of fish consumption was further evaluated by assessing POPs levels in serum from young women (15–24 years old) with markedly different patterns of fish consumption from Lake Managua. 2,2-bis(4-chlorophenyl)-1,1,1-trichloro-ethane (4,4′-DDT) and 2,2-bis(4-chlorophenyl)-1,1-dichloro-ethene (4,4′-DDE), γ-hexachlorocyclohexane (γ-HCH), polychlorinated biphenyls, pentachlorophenol, and polychlorobiphenylols were quantified in all samples. In general, the levels observed were higher than those reported in children from developed countries, such as Germany and United States. Toxaphene, aldrin, dieldrin, and ß-HCH could not be identified in any sample. The children working at the waste-disposal site had higher levels of POPs compared with the nonworking reference groups. In children not working, there were also gradients for several POPs, according to vicinity to the waste-disposal site. Moreover, in children, as well as in young women, there were gradients according to fish consumption. The most abundant component was 4,4′-DDE, but at levels still lower than those reported in children from malarious areas with a history of recent or current application of 4,4′-DDT for vector control.
Prenatal exposures to polybrominated diphenyl ethers (PBDEs) can harm neurodevelopment in humans and animals. In 2003–2004, PentaBDE and OctaBDE were banned in California and phased-out of US ...production; resulting impacts on human exposures are unknown. We previously reported that median serum concentrations of PBDEs and their metabolites (OH-PBDEs) among second trimester pregnant women recruited from San Francisco General Hospital (2008–2009; n = 25) were the highest among pregnant women worldwide. We recruited another cohort from the same clinic in 2011–2012 (n = 36) and now compare serum concentrations of PBDEs, OH-PBDEs, polychlorinated biphenyl ethers (PCBs) (structurally similar compounds banned in 1979), and OH-PCBs between two demographically similar cohorts. Between 2008–2009 and 2011–2012, adjusted least-squares geometric mean (LSGM) concentrations of ∑PBDEs decreased 65% (95% CI: 18, 130) from 90.0 ng/g lipid (95% CI: 64.7, 125.2) to 54.6 ng/g lipid (95% CI: 39.2, 76.2) (p = 0.004); ∑OH-PBDEs decreased 6-fold (p < 0.0001); and BDE-47, -99, and -100 declined more than BDE-153. There was a modest, nonsignificant (p = 0.13) decline in LSGM concentrations of ∑PCBs and minimal differences in ∑OH-PCBs between 2008–2009 and 2011–2012. PBDE exposures are likely declining due to regulatory action, but the relative stability in PCB exposures suggests PBDE exposures may eventually plateau and persist for decades.
Polybrominated diphenyl ethers (PBDEs) were widely used as flame retardants in the past three decades. These compounds are lipophilic and easily cross the placenta from pregnant woman to fetus. It is ...not clear whether hydroxylated PBDEs (OH-PBDEs), with greater hydrophilicity, have different concentrations in maternal and cord serum samples. We analyzed PBDEs (BDE-28, -47, -99, -100, -153, -154, -209) and OH-PBDEs (6-OH-BDE-47, 5-OH-BDE-47, 4′-OH-BDE-49, 5′-OH-BDE-99) in 20 pairs of maternal and cord serum samples collected in Cincinnati, OH in 2011. The geometric mean concentration of ∑OH-BDEs (the sum of four OH-PBDEs) was 49.76 pg/mL in cord sera, higher than 32.84 pg/mL in maternal sera. Similarly, cord serum total BDEs had a higher geometric mean than maternal serum (45.51 vs 32.07 ng/g lipid). Equal or higher levels of total OH-BDEs and total BDEs in cord serum were observed in 85% and 80% of the mother–neonate pairs, respectively. The study suggests fetuses might receive higher OH-PBDE and PBDE exposure than their mothers.
The aim of the present study was to understand the placental transfer of polychlorinated biphenyls (PCBs), specific hydroxylated PCB metabolites (OH-PCBs), and pentachlorophenol (PCP) in blood serum, ...in a birth cohort from eastern Slovakia. During the period 2002–2004, cord blood specimens were collected in parallel with maternal specimens from women delivering in the two eastern Slovak districts of Michalovce and Svidnik/Stropkov. A total of 92 pairs of mother-cord specimens at delivery were selected for this study. 4-OH-CB107, 3-OH-CB153, 4-OH-CB146, 3′-OH-CB138, 4-OH-CB187, and 4′-OH-CB172 were quantified. The median concentrations of Σ
17PCBs, Σ
6OH-PCBs, and PCP in cord serum were 0.92, 0.33, and 0.69
ng/g wet wt., respectively and highly correlated with the corresponding maternal serum levels (correlations were
R
2
=
0.61, 0.78, and 0.82, respectively). The median cord to mother ratios of the Σ
17PCBs, Σ
6OH-PCBs, and PCP were 0.18, 0.75, and 1.10, respectively. The median ratio of the Σ
6OH-PCBs to the Σ
17 PCBs in the cord serum was 0.38 from wet weight based concentrations, which was about four times higher than the ratio of these compounds in maternal serum (0.09). PCP was more abundant than any PCB or OH-PCB congener measured in cord serum. The higher cord to maternal ratios of OH-PCB metabolites as compared with the parent compounds suggests either a higher placental transfer rate or greater metabolism in the fetus as compared with the maternal compartment. These findings are consistent with their preferential binding to TTR that can cross the placenta. The cord to maternal ratio varies by congener (e.g., 4-OH-CB107
=
0.58, 4-OH-CB146
=
0.74, 3′-OH-CB138
=
1.01).
The objective of this study was to assess blood concentrations of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), and their polychlorobiphenylol (OH-PCB) metabolites in ...humans with a high seafood intake. Samples were obtained from pregnant women in the Faroe Islands in 1994−1995 and from their children at 7 years of age to examine maternal transfer of the compounds to their child, age-dependent metabolism, and temporal changes. Maternal serum was dominated by 2,2‘,4,4‘-tetrabromodiphenyl ether (BDE-47), while 2,2‘,4,4‘,5,5‘-hexabromodiphenyl ether (BDE-153) prevailed in the children's serum seven years later. DecaBDE was present in both mothers and children up to 3 and 6 ng/g lipid weight, respectively. The ΣPCB concentration in the children averaged about 60% of the concentrations in their mothers, with median levels for both above 1 μg/g lipid weight and with similar PCB congener patterns. ΣOH-PCB serum concentrations from the mothers and their children showed ranges of 1.8−36 ng/g wet weight (ww) and 0.49−22 ng/g ww, respectively, with all OH-PCB congener concentrations being lower in the children, except for 2,3,3‘,4‘,5-pentachloro-4-biphenylol (4-OH-CB107). Children at 7 years of age are exposed to PCBs at levels only slightly below those of their mothers, and the increased 4-OH-CB107 concentrations in children could be due to age-related differences in PCB metabolism. The PBDE concentrations were similar in both mothers and their children. The main persistent organic pollutant concentrations in the children are most probably due to other environmental exposure than maternal transfer.
The over-riding aim of the present investigation was to obtain information concerning exposure that can be used as a basis for studies on the health of individuals residing in the Michalovce area of ...eastern Slovakia which is heavily contaminated by polychlorinated biphenyls (PCBs). Accordingly, this work focused on determination of serum concentrations of hydroxylated (OH−PCBs) and methylsulfonyl-substituted (MeSO2−PCBs) metabolites of PCBs. One hundred and twenty-two men and women, 20−59 years of age, living in the contaminated area and 175 from the control Stropkov/Svidnik district were selected randomly from 2047 sampled individuals. Following a specially designed cleanup, the levels of various congeners of OH−PCBs and MeSO2−PCBs in their serum were quantitated by gas chromatography and mass spectrometry, with comparison to authentic reference standards. The median concentrations of PCB congeners and their OH−PCB and MeSO2−PCB metabolites were 2−3-fold higher in residents of Michalovce than in the control region. The levels of certain OH−PCB metabolites were in the same high range as those of individual PCB congeners, whereas the MeSO2−PCB levels were significantly lower. The PCB and their metabolites were present at slightly higher concentrations in men than in women, and the serum levels of PCBs and MeSO2−PCBs increased with increasing age. Thus, the environmental contamination resulting from previous industrial production of PCBs has led to elevated concentrations of PCBs and their metabolites in the serum of individuals living in the Michalovce area.
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