bde-197 and 2-2--4-4--tetrabromodiphenyl-ether

This study evaluated decabromodiphenyl ether (BDE-209) anaerobic debromination and bacterial community changes in mangrove sediment. BDE-209 debromination rates were enhanced with zerovalent iron compared to without zerovalent iron in the sediment. BDE-209 debromination rates in microcosms constructed with sediments collected in autumn were higher than in microcosms constructed with sediments collected in spring and were higher at the Bali sampling site than the Guandu sampling site. The intermediate products resulting from the reductive debromination of BDE-209 in sediment were nona-BDE (BDE-206, BDE-207), octa-BDEs (BDE-196, BDE-197), hepta-BDEs (BDE-183, BDE-184, BDE-191), hexa-BDEs (BDE-137, BDE-138, BDE-154, BDE-157), penta-BDEs (BDE-85, BDE-99, BDE-100, BDE-126), tetra-BDEs (BDE-47, BDE-49, BDE-66, BDE-77), tri-BDEs (BDE-17, BDE-28), and di-BDEs (BDE-15). Fifty bacterial genera associated with BDE-209 debromination were identified. Overall, 12 of the 50 bacterial genera were reported to be involved in dehalogenation of aromatic compounds. These bacteria have high potential to be BDE-209 debromination bacteria. Different combinations of bacterial community composition exhibit different abilities for BDE-209 anaerobic debromination.

Topics: Bacteria; Biodegradation, Environmental; Halogenated Diphenyl Ethers; Polybrominated Biphenyls; Wetlands

There are limited data concerning the placenta transfer characteristics and accumulation of polybrominated diphenyl ethers (PBDEs) in infants. However, PBDEs received increasing health concerns due to their endocrine disrupt and neurodevelopment toxicity effects. The present study assessed the accumulation of PBDEs in 30 paired placenta, breast milk, fetal cord blood, and neonatal urine samples collected from five major cities of the South China. The age of mothers ranged from 21 to 39 (mean 27.6±4.56). The ∑PBDE concentrations were 15.8±9.88 ng g(-1) lipid in placenta, 13.2±7.64 ng g(-1) lipid in breast milk, 16.5±19.5 ng g(-1) lipid in fetal cord blood, and 1.80±1.99 ng ml(-1) in neonatal urine. BDE-47 was the predominant congener in all types of human sample. Octa-BDEs such as BDE-196/-197 were detected highly in placenta and cord blood while moderately in breast milk and neonatal urine. Significant (p<0.01) correlations were observed for both total and most individual PBDEs in cord blood-maternal placenta and breast milk-urine paired individual samples. The extent of placental transfer of higher brominated BDEs such as BDE-196/-197 was greater than that of BDE-47. The estimated daily intake (EDI) analysis for breast-fed infants revealed that newborns in these areas were exposed to relatively high levels of PBDEs via breast milk. Our study not only provided systematic fundamental data for PBDE distribution but also revealed the placenta transfer characteristics of PBDE congeners in South China.

Topics: Adult; Breast Feeding; China; Environmental Pollutants; Female; Fetal Blood; Fetus; Halogenated Diphenyl Ethers; Humans; Infant; Infant, Newborn; Maternal Exposure; Maternal-Fetal Exchange; Milk, Human; Mothers; Placenta; Pregnancy

Data on early human fetal exposure to polybrominated diphenyl ethers (PBDEs) is limited. However, early pregnancy, in particular the first trimester, is critical for fetal development. We investigated exposure to PBDEs and placental transfer during early pregnancy by analyzing PBDEs in paired aborted fetuses (n = 65), placentas (n = 65), and maternal blood samples (n = 31) at 10-13 weeks gestation, which were collected in a hospital near electronic wastes (e-wastes) recycling sites in Taizhou, China. Mean total PBDE (∑PBDE) concentrations were 4.46, 7.90, and 15.7 ng/g of lipid weight (lw) in the fetuses, placentas, and blood, respectively. The three matrices had roughly similar PBDE congener profiles, dominated by BDE-209, BDE-197, BDE-153, BDE-47, and BDE-28. Significant correlations were found between ∑PBDE concentrations in the paired matrices. Comparing the concentration ratios between the paired samples, we observed significantly higher fetus/blood and fetus/placenta ratios for BDE-28, BDE-99, and BDE-47 than for BDE-197, BDE-209, and BDE-153, while opposite results were found in placenta/blood ratios. Our results indicate that PBDEs can enter the fetus during the first trimester and low-brominated congeners cross the placenta more easily than high-brominated congeners, which tend to remain in the placenta. This phenomenon is consistent with findings at the end of pregnancy.

Topics: Abortion, Induced; Adult; China; Electronic Waste; Female; Fetus; Halogenated Diphenyl Ethers; Humans; Maternal Exposure; Placenta; Polybrominated Biphenyls; Pregnancy; Pregnancy Trimester, First; Young Adult