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Project description:Polybrominated diphenyl ethers (PBDEs)
| PRJNA489665 | ENA
Project description:Polybrominated diphenyl ethers (PBDEs) are flame retardants that have been used in consumer products and furniture for three decades. Currently, very little is known about their fate in the environment and specifically about their susceptibility to aerobic biotransformation. Here, we investigated the ability of the polychlorinated biphenyl (PCB) degrading bacteria Rhodococcus jostii RHA1 and Burkholderia xenovorans LB400 to transform mono- through hexa-BDEs at ppb levels. We also tested the PBDE transforming abilities of the related strain Rhodococcus sp. RR1 and the ether-degrading Pseudonocardia dioxanivorans CB1190. The two PCB-degrading strains transformed all of the mono- through penta-BDEs and strain LB400 transformed one of the hexa-BDEs. The extent of transformation was inversely proportional to the degree of bromination. Strains RR1 and CB1190 were only able to transform the less brominated mono- and di-BDE congeners. RHA1 released stoichiometric quantities of bromide while transforming mono- and tetra-BDE congeners. LB400 instead converted most of a mono-BDE to a hydroxylated mono-BDE. This is the first report of aerobic transformation of tetra-, penta,- and hexa-BDEs as well as the first report of stoichiometric release of bromide during PBDE transformation.
| S-EPMC4288821 | biostudies-literature
Project description:Polybrominated diphenyl ethers (PBDEs) are "emerged" contaminants that were produced and used as flame retardants in numerous consumer and industrial applications for decades until banned. They remain ubiquitously present in the environment today. Here, a unique set of >200 biotic samples from the Antarctic was analyzed for PBDEs, including phytoplankton, krill, fish, and fur seal milk, spanning several sampling seasons over 14 years. PBDE-47 and -99 were the dominant congeners determined in all samples, constituting >60% of total PBDEs. A temporal trend was observed for ∑7PBDE concentrations in fur seal milk, where concentrations significantly increased (R2 = 0.57, p < 0.05) over time (2000-2014). Results for krill and phytoplankton also suggested increasing PBDE concentrations over time. Trends of PBDEs in fur seal milk of individual seals sampled 1 or more years apart showed no clear temporal trends. Overall, there was no indication of PBDEs decreasing in Antarctic biota yet, whereas numerous studies have reported decreasing trends in the northern hemisphere. Similar PBDE concentrations in perinatal versus nonperinatal milk implied the importance of local PBDE sources for bioaccumulation. These results indicate the need for continued assessment of contaminant trends, such as PBDEs, and their replacements, in Antarctica.
| S-EPMC6045470 | biostudies-literature
Project description:DE-71, a commercial mixture of the polybrominated diphenyl ethers (PBDEs), is used as flame retardant and the potential exposure to PBDEs is an emerging public health concern. It has been clarified that long term exposure to PBDEs induces hepatocellular carcinoma in mouse. In this study, we analyzed how DE-71 impacts on DNA methylation in hepatocellular carcinoma.
2017-01-01 | GSE73326 | GEO
Project description:RNA sequence analysis showed that PBDE47 had estrogenic activity through cell cycle regulation, and PBDE100 and PBDE153 had anti-estrogenic activity throguth ER and AhR cross talk.
2019-03-04 | GSE111203 | GEO
Project description:BackgroundThere is increasing interest in the potential effects of polybrominated diphenyl ethers (PBDEs) on children's neuropsychological development, but only a few small studies have evaluated such effects.ObjectivesOur goal was to examine the association between PBDE concentrations in colostrum and infant neuropsychological development and to assess the influence of other persistent organic pollutants (POPs) on such association.MethodsWe measured concentrations of PBDEs and other POPs in colostrum samples of 290 women recruited in a Spanish birth cohort. We tested children for mental and psychomotor development with the Bayley Scales of Infant Development at 12-18 months of age. We analyzed the sum of the seven most common PBDE congeners (BDEs 47, 99, 100, 153, 154, 183, 209) and each congener separately.ResultsIncreasing ?7PBDEs concentrations showed an association of borderline statistical significance with decreasing mental development scores (? per log ng/g lipid = -2.25; 95% CI: -4.75, 0.26). BDE-209, the congener present in highest concentrations, appeared to be the main congener responsible for this association (? = -2.40, 95% CI: -4.79, -0.01). There was little evidence for an association with psychomotor development. After adjustment for other POPs, the BDE-209 association with mental development score became slightly weaker (? = -2.10, 95% CI: -4.66, 0.46).ConclusionsOur findings suggest an association between increasing PBDE concentrations in colostrum and a worse infant mental development, particularly for BDE-209, but require confirmation in larger studies. The association, if causal, may be due to unmeasured BDE-209 metabolites, including OH-PBDEs (hydroxylated PBDEs), which are more toxic, more stable, and more likely to cross the placenta and to easily reach the brain than BDE-209.
| S-EPMC3548276 | biostudies-literature
Project description:Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants that were extensively used in commercial products. PBDEs are ubiquitous environmental contaminants that are both lipophilic and bioaccumulative. Effects of PBDEs on adipogenesis were studied in the 3T3-L1 preadipocyte cell model in the presence and absence of a known adipogenic agent, dexamethasone (DEX). A PBDE mixture designed to mimic body burden of North Americans was tested, in addition to the technical mixture DE-71 and the individual congener BDE-47. The mixture, DE-71, and BDE-47 all induced adipocyte differentiation as assessed by markers for terminal differentiation [fatty acid binding protein 4 (aP2) and perilipin] and lipid accumulation. Characterization of the differentiation process in response to PBDEs indicated that adipogenesis induced by a minimally effective dose of DEX was enhanced by these PBDEs. Moreover, C/EBPα, PPARγ, and LXRα were induced late in the differentiation process. Taken together, these data indicate that adipocyte differentiation is induced by PBDEs; they act in the absence of glucocorticoid and enhance glucocorticoid-mediated adipogenesis.
| S-EPMC3983240 | biostudies-literature
Project description:Hydroxylated polybromodiphenyl ethers (OH-PBDEs) are emerging aquatic pollutants, but their origins in the environment are not fully understood. There is evidence that OH-PBDEs are formed from bromophenols, but the underlying transformation processes remain unknown. Here, we investigate if the photoformation of OH-PBDEs from 2,6-dibromophenol in aqueous solution involves 2,6-bromophenoxyl radicals. After the UV irradiation of an aqueous 2,6-dibromophenol solution, HPLC-LTQ-Orbitrap MS and GC-MS analysis revealed the formation of a OH-PBDE and a dihydroxylated polybrominated biphenyl (di-OH-PBB). Both dimeric photoproducts were tentatively identified as 4'-OH-BDE73 and 4,4'-di-OH-PBB80. In addition, three debromination products (4-OH-BDE34, 4'-OH-BDE27, and 4,4'-di-OH-PBBs) were observed. Electron paramagnetic resonance spectroscopy revealed the presence of a 2,6-dibromophenoxyl radical with a six-line spectrum (a(H) (2 meta) = 3.45 G, a(H) (1 para) = 1.04 G, g = 2.0046) during irradiation of a 2,6-dibromophenol solution in water. The 2,6-dibromophenoxyl radical had a relatively long half-life (122 ± 5 ?s) according to laser flash photolysis experiments. The para-para C-C and O-para-C couplings of these 2,6-dibromophenoxyl radicals are consistent with the observed formation of both dimeric OH-PBDE and di-OH-PBB photoproducts. These findings show that bromophenoxyl radical-mediated phototransformation of bromophenols is a source of OH-PBDEs and di-OH-PBBs in aqueous environments that requires further attention.
| S-EPMC4717839 | biostudies-literature
Project description:Cross-sectional surveys of human blood and breast milk show increasing concentrations of polybrominated diphenyl ethers (PBDEs) that parallel the expanded use in consumer products, but longitudinal studies are lacking. We compared levels of major BDE congeners in archived 1994-1995 blood samples collected from a cohort of frequent and infrequent Great Lakes fish consumers with levels in the blood collected from the same individuals in 2001-2003 and 2004-2005. In mixed linear regression models controlling for multiple measurements per individual and covariates, statistically significant increases were seen from 1994-1995 to 2001-2003 for ?PBDEs and BDE-47, 99, and 153 and from 1994-1995 to 2004-2005 for ?PBDEs and BDE-99, 100, and 153, but ?PBDEs and BDE congeners did not change significantly between 2001-2003 and 2004-2005. Changes in body burdens of ?PBDEs and BDE-47, 100, and 153 in men were modified by BMI, with greater increases in men with higher BMI. Increases in BDE-153 were greater for women than men, and a greater increase in BDE-100 was found in older participants. There was a shift in the congener distribution with a significant increase in the proportion of BDE-153 relative to BDE-47 from 2001-2003 to 2004-2005.
| S-EPMC2951838 | biostudies-literature
Project description:Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants. Technical mixtures PentaBDE and OctaBDE were phased out in 2004 through voluntary and regulatory actions with DecaBDE remaining in limited use until 2013. Biomonitoring studies have shown widespread presence of PBDEs in the US and worldwide population. While some studies suggest that human serum concentrations are declining over time, it is unclear whether this trend will continue. Our objective was to examine temporal trends of PentaBDEs and their hydroxylated metabolites (OH-PBDEs) between 2008 and 2014 in populations of ethnically diverse, pregnant women residing in Northern California (n = 111). Serum samples were collected and analyzed by high resolution mass spectrometry for five PentaBDE congeners and two OH-PBDEs. We found widespread exposures in participants from all three time points (2008/09, 2011/12, 2014). Temporal patterns varied substantially by congener. BDE-47, -99 and the OH-PBDEs decreased between 2008/09-2011/12 but plateaued between 2011/12-2014. In contrast, BDE-100 decreased across all years, BDE-153 decreased in the latter years, and BDE-28 decreased initially and then increased. These findings indicate that while policies to remove PBDEs from the marketplace have successfully lead to declines in exposures to some PBDE congeners, human exposures to these legacy pollutants could plateau and remain ubiquitous in human populations.
| S-EPMC6628930 | biostudies-literature