Flame retardant exposure: polybrominated diphenyl ethers in blood from Swedish workers.

Science.gov (United States)

Sjödin, A; Hagmar, L; Klasson-Wehler, E; Kronholm-Diab, K; Jakobsson, E; Bergman, A

1999-08-01

Polybrominated diphenyl ethers (PBDEs) are used as additives in polymers and textiles to prohibit the development of fires. Because of the production and use of PBDEs, their lipophilic characteristics, and persistence, these compounds have become ubiquitous environmental contaminants. The aim of the present study was to determine potential exposures of PBDEs to clerks working full-time at computer screens and personnel at an electronics-dismantling plant, with hospital cleaners as a control group. Five PBDE congeners--2,2',4,4'-tetraBDE; 2,2',4,4',5,5'-hexaBDE; 2,2',4,4',5, 6'-hexaBDE; 2,2',3,4,4',5',6-heptaBDE; and decaBDE--were quantified in blood serum from all three categories of workers. Subjects working at the dismantling plant showed significantly higher levels of all PBDE congeners in their serum as compared to the control group. Decabromodiphenyl ether is present in concentrations of 5 pmol/g lipid weight (lw) in the personnel dismantling electronics; these concentrations are comparable to the concentrations of 2,2',4, 4'-tetraBDE. The latter compound was the dominating PBDE congener in the clerks and cleaners. The major compound in personnel at the dismantling plant was 2,2',3,4,4',5',6-heptaBDE. Concentrations of this PBDE congener are almost twice as high as for 2,2',4, 4'-tetraBDE in these workers and seventy times the level of this heptaBDE in cleaners. The total median PBDE concentrations in the serum from workers at the electronics-dismantling plant, clerks, and cleaners were 37, 7.3, and 5.4 pmol/g lw, respectively. The results show that decabromodiphenyl ether is bioavailable and that occupational exposure to PBDEs occurs at the electronics-dismantling plant.

Temporal trends of polychlorinated biphenyls, polybrominated diphenyl ethers, and perfluorinated compounds in Chinese sturgeon (Acipenser sinensis) eggs (1984-2008).

Science.gov (United States)

Jianxian, Sun; Hui, Peng; Jianying, Hu

2015-02-03

Because investigation on the temporal trends of persistent halogenated compounds (PHCs) is necessary to predict their future impacts on the environment and human health and evaluate the effectiveness of regulations on their production and usage, it is of concern to investigate annual temporal trends of PHCs in biota samples. This study examined the temporal trends of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorinated compounds (PFCs) in Chinese sturgeon (Acipenser sinensis) eggs over a period of 25 years (1984-2008), and 62 PCBs (19.2-1030 ng/g dw for total PCBs), 16 PBDEs (4.7-572 ng/g dw for total PBDEs), and 14 PFCs (26-46 ng/g dw for total PFCs) were detected. Although a decreasing temporal trend was observed for total PCBs with annual reduction rate of 3.4% (ρ = 0.005), a clear break point was observed around 1991, indicating their continuing emission in the 1980s in China. All major PBDEs showed increasing temporal trends, with annual change rates at 3.5-10.2% over the 25 years, but a sharp decreasing trend was observed after 2006, indicating a rapid response to the banning of PBDE usage in China in 2004. The greatest annual rate of increase was observed for BDE-28 (10.2%) followed by BDE-100 (7.7%), which would be due to metabolism input from higher brominated PBDEs. Significantly increasing temporal trends were observed for all PFCs, and the annual rates of increase were 7.9% and 5.9% for total perfluorinated carboxylic acids and perfluorooctanesulfonate (PFOS), respectively. A peak concentration for PFOS was observed in 1989, which may be related to the import history of PFCs in China. The present study is the first report of systematic temporal trends of PHCs in biota samples from China and shows that regulatory policy is needed to reduce their potential health and ecological risk in China considering the increasing temporal trends of PBDEs and PFCs.

Dehalogenation of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyl by Bimetallic, Impregnated, and Nanoscale Zerovalent Iron

Science.gov (United States)

Zhuang, Yuan; Ahn, Sungwoo; Seyfferth, Angelia L.; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G.

2011-01-01

Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zero-valent, which shows the difficulty with in-situ synthesis of a significant fraction of zero-valent iron in the micro-porous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogenous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI. PMID:21557574

Thermal and Optical Properties of New Poly(amide-imide)/Nanocomposite Reinforced by Layer Silicate Containing Diphenyl Ether Moieties

Science.gov (United States)

Faghihi, Khalil; Faramarzi, Ellahe; Shabanian, Meisam

2011-04-01

New poly(amide-imide)-montmorillonite reinforced nanocomposites containing Bis(4-N-trimellitylimido) diphenyl ether moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 4 was synthesized by the direct polycondensation reaction of Bis(4-N-trimellitylimido) diphenyl ether 3 with 4,4'-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 10 and 20 mass% silicate particles respectively, were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The properties of nanocomposites films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

Polybrominated diphenyl ethers in marine ecosystems of the American continents: foresight from current knowledge.

Science.gov (United States)

Shaw, Susan D; Kannan, Kurunthachalam

2009-01-01

Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta- and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.

Landfills as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

Science.gov (United States)

Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

2011-02-01

In order to investigate landfills as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two landfills (one active and one closed) and two reference sites using high volume air samplers. Contaminants were accumulated on glass fiber filters (particle phase) and PUF/XAD-2/PUF cartridges (gas phase), extracted by methyl-tert butyl ether/acetone (neutral PFCs), methanol (ionic PFCs) or hexane/acetone (PBDEs, musk fragrances), and detected by GC-MS (neutral PFCs, PBDEs, musk fragrances) or HPLC-MS/MS (ionic PFCs). Total concentrations ranged from 84 to 706 pg m -3 (volatile PFCs, gas phase), from fragrances, gas + particle phase) and from 1 to 11 pg m -3 (PBDEs, gas + particle phase). Observed sum concentrations of PFCs and synthetic musk fragrances and partly PBDE concentrations were elevated at landfill sites compared to corresponding reference sites. Concentrations determined at the active landfill were higher than those of the inactive landfill. Overall, landfills can be regarded as a source of synthetic musk fragrances, several PFCs and potentially of PBDEs to ambient air.

Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

Science.gov (United States)

Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

2016-08-01

The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

Historical trends and ecological risks of polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs) in a mangrove in South China.

Science.gov (United States)

Wu, Qihang; Liu, Xucheng; Liang, Chaozong; Leung, Jonathan Y S; Li, Huosheng; Chen, Shejun; Mai, Bixian; Miao, Shenyu; Chen, Yongheng; Wu, Zhifeng; Chen, Zhanghe

2017-12-01

While the production of polybrominated diphenyl ethers (PBDEs) was gradually phased out in the last decade, they may still pose hidden danger to the environment due to their toxicity and persistence. On the other hand, alternative halogenated flame retardants (AHFRs) have been increasingly used as substitutes for PBDEs and may further worsen environmental health. To determine the environmental impact of PBDEs and AHFRs, we examined the historical trends and ecological risks of PBDEs and AHFRs in a typical industrialized city in South China by measuring their concentrations in mangrove sediment. Results showed that the concentrations of PBDEs increased abruptly from 1997 to 2009 due to the use of commercial deca-BDE mixture, but were stabilized in recent years. The concentrations of AHFRs, mainly contributed by decabromodiphenyl ethane (DBDPE), kept increasing from 1997 onwards. Based on the temporal trends, DBDPE is predicted to be predominant over BDE 209 in future. Despite the observed similar concentration between BDE 209 and DBDPE, the former posed a high ecological risk, while the ecological risk of the latter was negligible. Therefore, more attention is required to manage the contamination of BDE 209 in the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Efficient and Practical Methods for the Preparation of Functionalized Aliphatic Trifluoromethyl Ethers.

Science.gov (United States)

Sokolenko, Taras M; Dronkina, Maya I; Magnier, Emmanuel; Yagupolskii, Lev M; Yagupolskii, Yurii L

2017-05-14

The "chlorination/fluorination" technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge–cyanobacteria associations

Science.gov (United States)

Guitart, Carlos; Slattery, Marc; Ankisetty, Sridevi; Radwan, Mohamed; Ross, Samir J.; Letcher, Robert J.; Reddy, Christopher M.

2016-01-01

Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon (14C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2′-OHBDE68, 2′,6-diOH-BDE159, and a recently identified compound, 2′-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C12H22O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds. PMID:21276990

Evaluation of Efficient and Practical Methods for the Preparation of Functionalized Aliphatic Trifluoromethyl Ethers

Directory of Open Access Journals (Sweden)

Taras M. Sokolenko

2017-05-01

Full Text Available The “chlorination/fluorination” technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs), Triclosan, and Related Compounds in Freshwater and Coastal Systems.

Science.gov (United States)

Kerrigan, Jill F; Engstrom, Daniel R; Yee, Donald; Sueper, Charles; Erickson, Paul R; Grandbois, Matthew; McNeill, Kristopher; Arnold, William A

2015-01-01

Hydroxylated polybrominated diphenyl ethers (OH-BDEs) are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin) photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once) 6'-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities.

Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs, Triclosan, and Related Compounds in Freshwater and Coastal Systems.

Directory of Open Access Journals (Sweden)

Jill F Kerrigan

Full Text Available Hydroxylated polybrominated diphenyl ethers (OH-BDEs are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once 6'-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities.

Spatial trends of polybrominated diphenyl ether (PBDE) congeners

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

High levels of medium-chain chlorinated paraffins and polybrominated diphenyl ethers on the inside of several household baking oven doors.

Science.gov (United States)

Gallistl, Christoph; Sprengel, Jannik; Vetter, Walter

2018-02-15

Fat obtained by wipe tests on the inner surface of 21 baking ovens from Stuttgart (Germany) were analyzed for halogenated flame retardants (HFRs), namely polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), dechlorane plus (DP), short- and medium-chain chlorinated paraffins (SCCPs, MCCPs), as well as polychlorinated biphenyls (PCBs). In ~50% of the samples chlorinated paraffins (CPs) were present in the mg/g fat range, i.e. three to four orders of magnitude higher concentrated than the sum of all other target compounds. In contrast the remaining ~50% of the samples were free of CPs, while the other HFRs were comparable in CP-positive and CP-negative samples. The exceptionally high concentrations and exclusive presence of CPs in half of the samples produced strong evidence that these compounds were released from the baking oven itself. This hypothesis was supported by detection of MCCPs at even higher concentrations in the inner components of one dismantled baking oven. The release of substantial amounts of HFRs from the oven casing during its use may contribute to human exposure to these compounds, especially MCCPs and SCCPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Passive air sampling of polychlorinated biphenyls, organochlorine compounds, and polybrominated diphenyl ethers across Asia.

Science.gov (United States)

Jaward, Foday M; Zhang, Gan; Nam, Jae Jak; Sweetman, Andrew J; Obbard, Jeffrey P; Kobara, Yuso; Jones, Kevin C

2005-11-15

Asia is of global importance economically, yet data on ambient persistent organic pollutant levels are still sparse for the region, despite international efforts under the Stockholm Convention to identify and reduce emissions. A large-scale passive air sampling survey was therefore conducted in Asia, specifically in China, Japan, South Korea, and Singapore. Polyurethane foam disks were deployed simultaneously at 77 sites, between Sept 21 and Nov 16, 2004, and analyzed for polychlorinated biphenyls (PCBs), organochlorine compounds (hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), chlordane), and polybrominated diphenyl ethers (PBDEs). The meteorological conditions prevailing in the region at this time facilitated the assessment of local/regional differences in atmospheric emissions, because large-scale advection effects due to monsoons or dust storms did not occur. Air concentrations estimated assuming an average sampler uptake rate of 3.5 m3/day ranged as follows (pg m(-3)): PCBs, 5-340; HCB, 10-460; DDTs, 0.4-1800; chlordanes, 1-660; PBDEs, < 0.13-340. South Korea and Singapore generally had regionally low concentrations. Elevated concentrations of PCBs, DDTs, and HCB occurred at sites in China, higher than reported in a similar recent sampling campaign in Europe. Chlordane was highest in samples from Japan (which also had elevated levels of PCBs and DDTs) and was also elevated in some Chinese locations. PBDE levels were generally low in the region.

Selective hydrogenolysis of Α–O–4, Β–O–4, 4–O–5 C–O bonds of lignin-model compounds and lignin-containing stillage derived from cellulosic bioethanol processing

NARCIS (Netherlands)

Gómez-Monedero, B.; Ruiz, M. P.; Bimbela, F.; Faria, J.

2017-01-01

Benzyl phenyl ether (BPE), phenethyl phenyl ether (PPE) and diphenyl ether (DPE) have been selected as model compounds of the most abundant and significant ether linkages found within the complex structure of lignin (e.g. α–O–4, β–O–4, and 4–O–5, respectively). The catalytic hydrogenolysis of these

Model for Photodegradation of Polybrominated Diphenyl Ethers

Czech Academy of Sciences Publication Activity Database

Veselý, M.; Vajglová, Zuzana; Kotas, Petr; Křišťál, Jiří; Ponec, Robert; Jiřičný, Vladimír

2015-01-01

Roč. 22, č. 7 (2015), s. 4949-4963 ISSN 0944-1344 R&D Projects: GA ČR GA104/09/0880; GA ČR(CZ) GAP105/12/0664 Institutional support: RVO:67985858 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * photodegradation model * quantum chemical calculation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.760, year: 2015

Cytotoxicity of S-conjugates of the sevoflurane degradation product fluoromethyl-2,2-difluoro-1-(trifluoromethyl) vinyl ether (Compound A) in a human proximal tubular cell line

International Nuclear Information System (INIS)

Altuntas, T. Gul; Zager, Richard A.; Kharasch, Evan D.

2003-01-01

Fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (FDVE) is a fluorinated alkene formed by degradation of the volatile anesthetic sevoflurane in anesthesia machines. FDVE is nephrotoxic in rats but not humans. Rat FDVE nephrotoxicity is attributed to FDVE glutathione conjugation and bioactivation of subsequent FDVE-cysteine S-conjugates, in part by renal β-lyase. Although FDVE conjugation and metabolism occur in both rats and humans, the mechanism for selective toxicity in rats and lack of effect in humans is incompletely elucidated. This investigation measured FDVE S-conjugate cytotoxicity in cultured human proximal tubular HK-2 cells, and compared this with known cytotoxic S-conjugates. HK-2 cells were incubated with FDVE and its GSH, cysteine S-mercapturic acid, cysteine S-sulfoxide, and mercapturic acid sulfoxide conjugates (0.1-2.7 mM) for 24 h. Cytotoxicity was determined by lactate dehydrogenase (LDH) release, total LDH, and the ability of viable cells to reduce a tetrazolium-based compound (MTT). FDVE was cytotoxic only at concentrations ≥0.9 mM. No increase in LDH release was observed with either FDVE-GSH conjugate. The FDVE-cysteine conjugates S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine (DFEC) and (Z)-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-FFVC) caused significant differences in LDH release and MTT reduction only at 2.7 mM; (Z)-FFVC was slightly more cytotoxic. Both S-(1,1-difluoro-2-fluoromethoxy-2-(trifluoromethyl) ethyl)-L-cysteine sulfoxide (DFEC-SO) and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine sulfoxide ((Z)-N-Ac-FFVC-SO) caused slightly greater changes in LDH release or total LDH than the corresponding equimolar DFEC and (Z)-N-acetyl-S-(1-fluoro-2-fluoromethoxy-2-(trifluoromethyl) vinyl)-L-cysteine ((Z)-N-Ac-FFVC) conjugates. In contrast to FDVE S-conjugates, S-(1,2-dichlorovinyl)-L-cysteine was markedly cytotoxic, at concentrations as low as 0

Complexity of Naturally Produced Polybrominated Diphenyl Ethers Revealed via Mass Spectrometry

Science.gov (United States)

Agarwal, Vinayak; Li, Jie; Rahman, Imran; Borgen, Miles; Aluwihare, Lihini I.; Biggs, Jason S.; Paul, Valerie J.; Moore, Bradley S.

2015-01-01

Polybrominated diphenyl ethers (PBDEs) are persistent and bioaccumulative anthropogenic and natural chemicals that are broadly distributed in the marine environment. PBDEs are potentially toxic due to inhibition of various mammalian signaling pathways and enzymatic reactions. PBDE isoforms vary in toxicity in accordance with structural differences, primarily in the number and pattern of hydroxyl moieties afforded upon a conserved core structure. Over four decades of isolation and discovery-based efforts have established an impressive repertoire of natural PBDEs. Based on our recent reports describing the bacterial biosyntheses of PBDEs, we predicted the presence of additional classes of PBDEs to those previously identified from marine sources. Using mass spectrometry and NMR spectroscopy, we now establish the existence of new structural classes of PBDEs in marine sponges. Our findings expand the chemical space explored by naturally produced PBDEs, which may inform future environmental toxicology studies. Furthermore, we provide evidence for iodinated PBDEs and direct attention toward the contribution of promiscuous halogenating enzymes in further expanding the diversity of these polyhalogenated marine natural products. PMID:25559102

Changes in concentrations of perfluorinated compounds, polybrominated diphenyl ethers, and polychlorinated biphenyls in Norwegian breast-milk during twelve months of lactation.

Science.gov (United States)

Thomsen, Cathrine; Haug, Line S; Stigum, Hein; Frøshaug, May; Broadwell, Sharon L; Becher, Georg

2010-12-15

At present, scientific knowledge on depuration rates of persistent organic pollutants (POPs) is limited and the previous assumptions of considerable reduction of body burdens through breast-feeding have recently been challenged. We therefore studied elimination rates of important POPs in nine Norwegian primiparous mothers and one mother breast-feeding her second child by collecting breast-milk samples (n = 70) monthly from about two weeks to up to twelve months after birth. Perfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and polychlorinated biphenyls (PCBs) were determined in the breast-milk samples. Linear mixed effect models were established for selected compounds, and significant decreases in the range of 1.2-4.7% in breast-milk concentrations per month were observed for a wide range of PCBs and PBDEs. For the first time, depuration rates for perfluorooctylsulfonate (PFOS) and perfluorooctanoic acid (PFOA) are presented, being 3.8 and 7.8% per month, respectively (p changes during the lactation period. After a year of nursing the breast-milk concentrations of PFCs, PBDEs, and PCBs were reduced by 15-94%.

Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

Energy Technology Data Exchange (ETDEWEB)

Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

2004-09-15

Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge-cyanobacteria associations

International Nuclear Information System (INIS)

Guitart, Carlos; Slattery, Marc; Ankisetty, Sridevi; Radwan, Mohamed; Ross, Samir J.; Letcher, Robert J.; Reddy, Christopher M.

2011-01-01

Research highlights: → O-PBDEs in the marine environment could have both natural and anthropogenic origin. → Molecular-level 14 C is measured by accelerated mass spectrometry. → Industrial products, derived from fossil sources, are radiocarbon 14 C-free. → O-PBDEs compounds from marine sponges show modern levels of 14 C. → Some species could produce O-PBDEs rather than being biotransformation from industrial PBDEs. - Abstract: Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon ( 14 C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14 C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14 C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2'-OH-BDE68, 2',6-diOH-BDE159, and a recently identified compound, 2'-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C 12 H 22 O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds.

Theoretical study on the mechanism and kinetics of the reaction of 2,2‧,4,4‧-tetrabrominated diphenyl ether (BDE-47) with OH radicals

Science.gov (United States)

Cao, Haijie; He, Maoxia; Han, Dandan; Sun, Yanhui; Xie, Ju

2011-03-01

The mechanism and kinetic properties of OH-initiated gas-phase reaction of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) have been studied at the MPWB1K/6-311 + G(3df,2p)//MPWB1K/6-31G(d) level of theory. Two types of reactions including hydroxyl addition and hydrogen abstraction have been considered. The calculation results indicate that addition reactions except for the bromo-substituted addition reaction have lower energy barriers than hydrogen abstraction reactions. Hydroxyl radical is most likely to be added to non-substituted C atoms (C(3), C(5), and C(6) atoms). Moreover, for all the reactions with OH radical, the bromo-substituted C atoms encountered the highest barrier compared to that of the rest C atoms. The rate constants and product branching ratios of each pathway have been deduced over a wide range of 200-1000 K using canonical variational transition state (CVT) theory with small curvature tunneling (SCT) contribution. This study can be regarded as an attempt to investigate the OH-initiated photochemical reaction mechanism of polybrominated diphenyl ethers (PBDEs).

An efficient synthesis of S-γ-[(4-trifluoromethyl)phenoxy] benzenepropanamine-[1-14C]maleate, an important metabolite of fluoxetine hydrochloride

International Nuclear Information System (INIS)

Wheeler, W.J.

1992-01-01

S-γ-[(4-Trifluoromethyl)phenoxy]benzenepropanamine-[1- 14 C] maleate has been prepared in six steps from R-(-)1-phenyl-1,2-ethanediol. The isotope was incorporated by the reaction of NaCN-[ 14 C] with the tert. butyldimethylsilyl ether of R-(-)1-phenyl-1,2-ethane-diol 2-tosylate. Borane reduction and arylation, followed by salt formation yielded S-γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[1- 14 C] maleate. (Author)

Prenatal exposure to polybrominated diphenyl ethers and child attention problems at 3–7 years

Science.gov (United States)

Cowell, Whitney J.; Lederman, Sally A.; Sjödin, Andreas; Jones, Richard; Wang, Shuang; Perera, Frederica P.; Wang, Richard; Rauh, Virginia A.; Herbstman, Julie B.

2016-01-01

Introduction Polybrominated diphenyl ethers (PBDEs) comprise a class of halogenated compounds used extensively as flame retardant chemicals in consumer products resulting in nearly ubiquitous human exposure. Mounting evidence suggests that PBDEs are developmental neurotoxicants; however, associations between early life exposure and child behavior have been largely limited to a single developmental time point. Methods The study population consists primarily of white, black and Chinese women who were pregnant on 11 September 2001 and delivered at 1 of 3 downtown New York City hospitals. Maternal–child pairs were followed through age 7 years. Cord blood was collected at delivery and PBDE plasma levels for 210 samples were analyzed by the U.S. Centers for Disease Control and Prevention. The Child Behavior Checklist, a validated maternal-report instrument used for assessing child behavior, was administered annually between the ages of 3 and 7 years. We analyzed the association between natural log-transformed and dichotomized (low vs. high) PBDEs and attention problems using multivariable adjusted negative binomial regression. Results We detected 4 PBDE congeners in more than 50% of samples, with concentrations highest for BDE-47 (median ± IQR: 11.2 ± 19.6 ng/g). In adjusted analyses, we detected associations between BDE-47 (1.21, 95% CI: 1.00, 1.47), and BDE-153 (1.18, 95% CI: 1.00, 1.39) in cord plasma and increased attention problems among children at age 4 (n = 109) but not 6 (n = 107) years. Conclusions Our findings demonstrate a positive trend between prenatal PBDE exposure and early childhood attention problems, and are consistent with previous research reporting associations between prenatal PBDE exposure and disrupted child behaviors. PMID:26344673

Meroterpenoid and diphenyl ether derivatives from Penicillium sp. MA-37, a fungus isolated from marine mangrove rhizospheric soil.

Science.gov (United States)

Zhang, Yi; Li, Xiao-Ming; Shang, Zhuo; Li, Chun-Shun; Ji, Nai-Yun; Wang, Bin-Gui

2012-11-26

Penicillium sp. MA-37, which was obtained from the rhizospheric soil of the mangrove plant Bruguiera gymnorrhiza, exhibited different chemical profiles in static and shaken fermentation modes. Three new meroterpenoid derivatives, 4,25-dehydrominiolutelide B (1), 4,25-dehydro-22-deoxyminiolutelide B (2), and isominiolutelide A (3), together with three known ones were characterized from its static fermentation, while three new diphenyl ether derivatives, namely, Δ(1('),3('))-1'-dehydroxypenicillide (4), 7-O-acetylsecopenicillide C (5), and hydroxytenellic acid B (6), along with five related metabolites were isolated from the shaken culture. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and the structure of compound 2 was confirmed by X-ray crystallographic analysis. The absolute configurations of 1-3 and 6 were determined by ECD and modified Mosher's method, respectively. All isolated compounds were evaluated for brine shrimp lethality and antibacterial activity.

Polybrominated diphenyl ethers in Mississippi River suspended sediment

Energy Technology Data Exchange (ETDEWEB)

Raff, J.; Hites, R. [Indiana Univ., Bloomington, IN (United States)

2004-09-15

The Mississippi River Basin drains water from 41% of the conterminous U.S. and is a valuable resource that supplies food, transportation, and irrigation to more than 95 million people of the region. Discharge and runoff from industry, agriculture, and population centers have increased the loads of anthropogenic organic compounds in the river. There has been growing concern over the rising levels of polybrominated diphenyl ethers (PBDEs) in air, sediment, biota, and humans, but there have been no studies to measure the concentrations of these chemicals in North America's largest river system. The goal of this study was to investigate the occurrence of PBDEs (15 congeners including BDE-209) and to identify possible sources within the Mississippi River Basin. We found PBDEs to be widespread throughout the region, rivaling PCBs in their extent and magnitude of contamination. We have also calculated the total amount of PBDEs released to the Gulf of Mexico in 2002.

Generation of Resistance to the Diphenyl Ether Herbicide, Oxyfluorfen, via Expression of the Bacillus subtilis Protoporphyrinogen Oxidase Gene in Transgenic Tobacco Plants.

Science.gov (United States)

Choi, K W; Han, O; Lee, H J; Yun, Y C; Moon, Y H; Kim, M; Kuk, Y I; Han, S U; Guh, J O

1998-01-01

In an effort to develop transgenic plants resistant to diphenyl ether herbicides, we introduced the protoporphyrinogen oxidase (EC 1.3.3.4) gene of Bacillus subtilis into tobacco plants. The results from a Northern analysis and leaf disc assay indicate that the expression of the B. subtilis protoporphyrinogen oxidase gene under the cauliflower mosaic virus 35S promoter generated resistance to the diphenyl ether herbicide, oxyfluorfen, in transgenic tobacco plants.

Pharmacological evaluation of halogenated and non-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles as D(2) and 5-HT(2A) receptor ligands.

Science.gov (United States)

Tomić, Mirko; Vasković, Djurdjica; Tovilović, Gordana; Andrić, Deana; Penjišević, Jelena; Kostić-Rajačić, Sladjana

2011-05-01

Five groups of previously synthesized and initially screened non-substituted and 4-halogenated arylpiperazin-1-yl-ethyl-benzimidazoles were estimated for their in-vitro binding affinities at the rat D(2) , 5-HT(2A) , and α(1) -adrenergic receptors. Among all these compounds, 2-methoxyphenyl and 2-chlorophenyl piperazines demonstrate the highest affinities for the tested receptors. The effects of 4-halogenation of benzimidazoles reveal that substitution with bromine may greatly increase the affinity of the compounds for the studied receptors, while the effect of substitution with chlorine is less remarkable. Most of the tested components show 5-HT(2A)/D(2) pK(i) binding ratios slightly above or less than 1, while only 4-chloro-6-(2-{4-[3-(trifluoromethyl)phenyl]piperazin-1-yl}ethyl)-1H-benzimidazole expresses an appropriate higher binding ratio (1.14), which was indicated for atypical neuroleptics. This compound exhibits a non-cataleptic action in rats and prevents d-amphetamine-induced hyperlocomotion in mice, which suggest its atypical antipsychotic potency. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interaction of polybrominated diphenyl ethers and aerobic granular sludge: biosorption and microbial degradation.

Science.gov (United States)

Ni, Shou-Qing; Cui, Qingjie; Zheng, Zhen

2014-01-01

As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209). Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contact time, and sludge dosage increased or solution pH dropped. Ionic strength had a negative influence on BDE-209 adsorption. The modified pseudo first-order kinetic model was appropriate to describe the adsorption kinetics. Microbial debromination of BDE-209 did not occur during the first 30 days of operation. Further study found that aerobic microbial degradation of 4,4(')-dibromodiphenyl ether happened with the production of lower BDE congeners.

Interaction of Polybrominated Diphenyl Ethers and Aerobic Granular Sludge: Biosorption and Microbial Degradation

Directory of Open Access Journals (Sweden)

Shou-Qing Ni

2014-01-01

Full Text Available As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209. Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contact time, and sludge dosage increased or solution pH dropped. Ionic strength had a negative influence on BDE-209 adsorption. The modified pseudo first-order kinetic model was appropriate to describe the adsorption kinetics. Microbial debromination of BDE-209 did not occur during the first 30 days of operation. Further study found that aerobic microbial degradation of 4,4′-dibromodiphenyl ether happened with the production of lower BDE congeners.

Substance Flow Analysis of Wastes Containing Polybrominated Diphenyl Ethers

DEFF Research Database (Denmark)

Vyzinkarova, Dana; Brunner, Paul H.

2013-01-01

materials. Therefore, end-of-life (EOL) plastic materials used for construction must be separated and properly treated, for example, in a state-of-the-art municipal solid waste (MSW) incinerator. In the case of cOctaBDE, the main flows are waste electrical and electronic equipment (WEEE) and, possibly......The present article examines flows and stocks of Stockholm Convention regulated pollutants, commercial penta- and octabrominated diphenyl ether (cPentaBDE, cOctaBDE), on a city level. The goals are to (1) identify sources, pathways, and sinks of these compounds in the city of Vienna, (2) determine...... the fractions that reach final sinks, and (3) develop recommendations for waste management to ensure their minimum recycling and maximum transfer to appropriate final sinks. By means of substance flow analysis (SFA) and scenario analysis, it was found that the key flows of cPentaBDE stem from construction...

Determination of polybrominated diphenyl ethers in environmental standard reference materials

Energy Technology Data Exchange (ETDEWEB)

Stapleton, Heather M.; Schantz, Michele M.; Wise, Stephen A. [National Institute of Standards and Technology, Analytical Chemistry Division, Gaithersburg, MD (United States); Keller, Jennifer M.; Kucklick, John R. [National Institute of Standards and Technology, Analytical Chemistry Division, Hollings Marine Laboratory, Charleston, SC (United States); Leigh, Stefan D. [National Institute of Standards and Technology, Statistical Engineering Division, Gaithersburg, MD (United States)

2007-04-15

Standard reference materials (SRMs) are valuable tools in developing and validating analytical methods to improve quality assurance standards. The National Institute of Standards and Technology (NIST) has a long history of providing environmental SRMs with certified concentrations of organic and inorganic contaminants. Here we report on new certified and reference concentrations for 27 polybrominated diphenyl ether (PBDE) congeners in seven different SRMs: cod-liver oil, whale blubber, fish tissue (two materials), mussel tissue and sediment (two materials). PBDEs were measured in these SRMs, with the lowest concentrations measured in mussel tissue (SRM 1974b) and the highest in sediment collected from the New York/New Jersey Waterway (SRM 1944). Comparing the relative PBDE congener concentrations within the samples, we found the biota SRMs contained primarily tetrabrominated and pentabrominated diphenyl ethers, whereas the sediment SRMs contained primarily decabromodiphenyl ether (BDE 209). The cod-liver oil (SRM 1588b) and whale blubber (SRM 1945) materials were also found to contain measurable concentrations of two methoxylated PBDEs (MeO-BDEs). Certified and reference concentrations are reported for 12 PBDE congeners measured in the biota SRMs and reference values are available for two MeO-BDEs. Results from a sediment interlaboratory comparison PBDE exercise are available for the two sediment SRMs (1941b and 1944). (orig.)

Developmental toxicity of diphenyl ether herbicides in nestling American kestrels.

Science.gov (United States)

Hoffman, D J; Spann, J W; LeCaptain, L J; Bunck, C M; Rattner, B A

1991-11-01

Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crown-rump length, and bone lengths including humerus, radius-ulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crown-rump, humerus, radius-ulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofen-treated groups, and increased plasma enzyme activities for ALT, AST, and LDH-L in the 250-mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50- and 250-mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species.

Metabolism of polybrominated diphenyl ethers and tetrabromobisphenol A by fish liver subcellular fractions in vitro.

Science.gov (United States)

Shen, Mengnan; Cheng, Jie; Wu, Ruohan; Zhang, Shenghu; Mao, Liang; Gao, Shixiang

2012-06-15

Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are two major flame retardants that accumulate in fish tissues and are potentially toxic. Their debrominated and oxidated derivatives were also reported in fish tissues although the sources of theses derivatives were unidentified. Our study was to determine whether PBDEs and TBBPA could be metabolized by fish liver subcellular fractions in vitro and to identify what types of metabolites were formed. Liver microsomes and S9 fractions of crucian carp (Carassius auratus) were exposed to 4,4'-dibromodiphenyl ether (BDE 15), 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) or TBBPA solutions for 4h. Exposure of liver subcellular fractions to BDE 15 resulted in the formation of bromophenol and two monohydroxylated dibromodiphenyl ether metabolites. Neither in microsomes nor in S9 studies has revealed the presence of hydroxylated metabolites with BDE 47 exposure which indicated that the oxidation reactions in vitro were hindered by the increased number of bromine substituents on the PBDEs. TBBPA underwent an oxidative cleavage near the central carbon of the molecule, which led to the production of 2,6-dibromo-4-isopropyl-phenol and three unidentified metabolites. Another metabolite of TBBPA characterized as a hexa-brominated compound with three aromatic rings was also found in the liver subcellular fractions. These results suggest that the biotransformation of BDE 15 and TBBPA in fish liver is mediated by cytochrome P450 (CYP450) enzymes, as revealed by the formation of hydroxylated metabolites and oxidative bond cleavage products. Moreover, further studies on the identification of specific CYP450 isozymes involved in the biotransformation revealed that CYP1A was the major enzyme responsible for the biotransformation of BDE 15 and TBBPA in fish liver subcellular fractions and CYP3A4 also played a major role in metabolism of TBBPA. Copyright © 2012 Elsevier B.V. All rights reserved.

Catalytic hydroprocessing of lignin β-O-4 ether bond model compound phenethyl phenyl ether over ruthenium catalysts

NARCIS (Netherlands)

Gomez-Monedero, B.; Faria, J.; Bimbela, F.; Ruiz, M.P.

2017-01-01

The catalytic hydroprocessing of phenethyl phenyl ether (PPE), a model compound of one of the most significant ether linkages within lignin structure, β-O-4, has been studied. Reactions were carried out using two ruthenium-based catalysts, supported on different materials: 3.8 wt.% Ru/C and 3.9 wt.%

Brominated dioxins/furans and hydroxylated polybrominated diphenyl ethers: Occurrences in commercial 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and 2,4,6-tribromophenol, and formation during synthesis of BTBPE.

Science.gov (United States)

Ren, Man; Zeng, Hao; Peng, Ping-An; Li, Hui-Ru; Tang, Cai-Ming; Hu, Jian-Fang

2017-07-01

Polybrominated dibenzo-p-dioxins (PBDDs) and hydroxylated polybrominated diphenyl ethers (OH-PBDEs) can be formed from bromophenols (BPs) by thermal degradation, biosynthesis or phototransformation. However, it is unknown whether PBDDs and OH-PBDEs can be formed during the chemical production processes that utilize BPs as raw materials. 2,4,6-tribromophenol (2,4,6-TBP) is an important raw material for the synthesis of 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), a novel brominated flame retardant. In this study, PBDDs, polybrominated dibenzofurans (PBDFs) and OH-PBDEs have been identified and quantified in commercially available BTBPE and 2,4,6-TBP. Furthermore, their formation as unintentional by-products during the laboratory synthesis of BTBPE from 2,4,6-TBP and 1,2-dibromoethane in the presence of sodium carbonate has also been investigated. 2,3,7,8-substituted PBDDs and PBDFs (2,3,7,8-PBDD/Fs) were undetectable in commercial samples of BTBPE and present in low levels (nanogram per gram) in 2,4,6-TBP. Two tetrabrominated dibenzo-p-dioxins (TeBDDs), namely 1,3,6,8- and 1,3,7,9-TeBDD, and three hydroxylated pentabrominated diphenyl ethers (OH-pentaBDEs), namely 4'-OH-BDE121, 2'-OH-BDE121, and 6'-OH-BDE100, were identified or tentatively identified, and quantitatively estimated to be at concentrations in the range of undetectable to several thousands of nanograms per gram in commercial BTBPE and 2,4,6-TBP. TeBDDs and OH-pentaBDEs were formed as by-products from 2,4,6-TBP during BTBPE synthesis. Further studies need to be conducted in order to determine whether PBDD/Fs and OH-PBDEs are also formed during the industrial synthesis of other chemical compounds that utilize BPs as raw materials or intermediates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosynthesis of polybrominated aromatic organic compounds by marine bacteria

Science.gov (United States)

Agarwal, Vinayak; El Gamal, Abrahim A.; Yamanaka, Kazuya; Poth, Dennis; Kersten, Roland D.; Schorn, Michelle; Allen, Eric E.; Moore, Bradley S.

2014-01-01

Polybrominated diphenyl ethers (PBDEs) and polybrominated bipyrroles are natural products that bioaccumulate in the marine food chain. PBDEs have attracted widespread attention due to their persistence in the environment and potential toxicity to humans. However, the natural origins of PBDE biosynthesis are not known. Here we report marine bacteria as producers of PBDEs and establish a genetic and molecular foundation for their production that unifies paradigms for the elaboration of bromophenols and bromopyrroles abundant in marine biota. We provide biochemical evidence of marine brominase enzymes revealing decarboxylative-halogenation enzymology previously unknown among halogenating enzymes. Biosynthetic motifs discovered in our study were used to mine sequence databases to discover unrealized marine bacterial producers of organobromine compounds. PMID:24974229

Brominated diphenyl ether levels. A comparison of tributary sediments versus biosolid material

Energy Technology Data Exchange (ETDEWEB)

Kolic, T.M.; MacPherson, K.A.; Reiner, E.J. [Ontario Ministry of the Environment, Laboratory Services Branch, Toronto, ON (Canada); Ho, T.; Kleywegt, S. [Ontario Ministry of the Environment, Standards Development Branch, Toronto, ON (Canada); Dove, A.; Marvin, C. [Environment Canada, Burlington, ON (Canada)

2004-09-15

PBDEs are persistent in the environment, have low water solubility and are known to have a tendency to bioaccumulate in wildlife and humans. There are 209 possible PBDE congeners. There has been concern over the bioaccumulation of these compounds since they have been found in mother's milk. Some of the brominated diphenyl ethers are known to metabolize into hydroxylated compounds and these metabolites are known to compete with and reduce thyroxine (T4) from binding to the thyroxine binding protein, transthyretin. This disrupts the thyroid hormone system interaction that has recently been notable amongst women in the form of hypothyroidism that can affect the fetus development in the form of neurodevelopmental deficits. There have been reports of estrogenic activities regarding PBDEs and their hydroxylated counterparts. Information such as this is indicative that PBDEs are endocrine disruptors. Due to their lipophilic nature, PBDEs have a high binding affinity to particulates and accumulate in sediments. Various reports on sediments and sludge type matrices have been reported in Austria, Switzerland, Netherlands and Canada. The following paper is a presentation of levels of PBDEs found in Tributary sediments and their comparison of levels to nearby biosolid sampling locations along Lake Ontario.

Overexpression of a specific soybean GmGSTU4 isoenzyme improves diphenyl ether and chloroacetanilide herbicide tolerance of transgenic tobacco plants.

Science.gov (United States)

Benekos, Kostantinos; Kissoudis, Christos; Nianiou-Obeidat, Irini; Labrou, Nikolaos; Madesis, Panagiotis; Kalamaki, Mary; Makris, Antonis; Tsaftaris, Athanasios

2010-10-01

Plant glutathione transferases (GSTs) superfamily consists of multifunctional enzymes and forms a major part of the plants herbicide detoxification enzyme network. The tau class GST isoenzyme GmGSTU4 from soybean, exhibits catalytic activity towards the diphenyl ether herbicide fluorodifen and is active as glutathione-dependent peroxidase (GPOX). Transgenic tobacco plants of Basmas cultivar were generated via Agrobacterium transformation. The aim was to evaluate in planta, GmGSTU4's role in detoxifying the diphenyl ether herbicides fluorodifen and oxyfluorfen and the chloroacetanilides alachlor and metolachlor. Transgenic tobacco plants were verified by PCR and Southern blot hybridization and expression of GmGSTU4 was determined by RT-PCR. Leaf extracts from transgenic plants showed moderate increase in GST activity towards CDNB and a significant increase towards fluorodifen and alachlor, and at the same time an increased GPOX activity towards cumene hydroperoxide. GmGSTU4 overexpressing plants when treated with 200 μM fluorodifen or oxyfluorfen exhibited reduced relative electrolyte leakage compared to wild type plants. Moreover all GmGSTU4 overexpressing lines exhibited significantly increased tolerance towards alachlor when grown in vitro at 7.5 mg/L alachlor compared to wild type plants. No significant increased tolerance was observed to metolachlor. These results confirm the contribution of this particular GmGSTU4 isoenzyme from soybean in the detoxification of fluorodifen and alachlor, and provide the basis towards the development of transgenic plants with improved phytoremediation capabilities for future use in environmental cleanup of herbicides. Copyright © 2010 Elsevier B.V. All rights reserved.

Concentrations of Polybrominated Diphenyl Ethers (PBDEs) and 2,4,6-Tribromophenol in Human Placental Tissues

Science.gov (United States)

Leonetti, Christopher; Butt, Craig M.; Hoffman, Kate; Miranda, Marie Lynn; Stapleton, Heather M.

2015-01-01

Legacy environmental contaminants such as polybrominated diphenyl ethers (PBDEs) are widely detected in human tissues. However, few studies have measured PBDEs in placental tissues, and there are no reported measurements of 2,4,6-tribromophenol (2,4,6-TBP) in placental tissues. Measurements of these contaminants are important for understanding potential fetal exposures, as these compounds have been shown to alter thyroid hormone regulation in vitro and in vivo. In this study, we measured a suite of PBDEs and 2,4,6-TBP in 102 human placental tissues collected between 2010–2011 in Durham County, North Carolina, USA. The most abundant PBDE congener detected was BDE-47, with a mean concentration of 5.09 ng/g lipid (range: 0.12–141 ng/g lipid; detection frequency 91%); however, 2,4,6-TBP was ubiquitously detected and present at higher concentrations with a mean concentration of 15.4 ng/g lipid (range:1.31–316 ng/g lipid; detection frequency 100%). BDE-209 was also detected in more than 50% of the samples, and was significantly associated with 2,4,6-TBP in placental tissues, suggesting they may have a similar source, or that 2,4,6-TBP may be a degradation product of BDE-209. Interestingly, BDE-209 and 2,4,6-TBP were negatively associated with age (rs=−0.16; p=0.10 and rs=−0.17; p=0.08, respectively). The results of this work indicate that PBDEs and 2,4,6-TBP bioaccumulate in human placenta tissue and likely contribute to prenatal exposures to these environmental contaminants. Future studies are needed to determine if these joint exposures are associated with any adverse health measures in infants and children. PMID:26700418

Global assessment of polybrominated diphenyl ethers in farmed and wild salmom

Energy Technology Data Exchange (ETDEWEB)

Hites, R. [Indiana Univ., Bloomington, IN (United States); Foran, J. [Midwest Center for Environmental Science, Milwaukee, WI (United States); Schwager, S.; Knuth, B. [Cornell Univ., Ithaca, NY (United States); Hamilton, C. [AXYS Analytical, Sydney (Australia); Carpenter, D. [Albany Univ., NY (United States)

2004-09-15

Despite their societal benefits, polybrominated diphenyl ethers (PBDEs) seem to be migrating from the products in which they are used and entering the environment and people. PBDEs are now ubiquitous; they can be found in air, water, fish, birds, marine mammals, and people, and in most cases, the concentrations of these compounds have increased dramatically over the last 20 years. One source of PBDEs in people is their food supply, and an increasingly important food is salmon, which is nutritious and high in beneficial fats. Between 1987 and 1999, salmon consumption increased annually at a rate of 10-20%. Currently, over half the salmon sold globally is farm-raised in Northern Europe, Chile, Canada, and the United States, and the annual global production of farmed salmon (predominantly Atlantic salmon) has risen from {proportional_to}27,000 to over 1 million metric tons during the past two decades. The health benefits of eating fish such as salmon have been well documented. However, salmon are relatively fatty, carnivorous fish that feed high in the food web, and as such, they bioaccumulate contaminants. In a previous study, we reported that levels of persistent, bioaccumulative contaminants (such as PCBs, dioxins, and several chlorinated pesticides) are significantly higher in farm-raised salmon than in wild salmon and that salmon raised on European farms have significantly greater toxic contaminant loads than those raised on North and South American farms. In this report, we provide results on polybrominated diphenyl ether concentrations in salmon purchased from farms in eight major salmon farming regions, in five species of wild Pacific salmon, and in salmon fillets purchased at supermarkets in North America and Europe.

Biomagnification of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls in a highly contaminated freshwater food web from South China

International Nuclear Information System (INIS)

Wu Jiangping; Luo Xiaojun; Zhang Ying; Yu Mei; Chen Shejun; Mai Bixian; Yang Zhongyi

2009-01-01

To evaluate the biomagnification extent of polybrominated diphenyls ethers (PBDEs) and polychlorinated biphenyls (PCBs) in a highly contaminated freshwater food web from South China, trophic magnification factors (TMFs) for 18 PBDE congeners and 53 PCB congeners were calculated. The TMF values ranged 0.26-4.47 for PBDEs and 0.75-5.10 for PCBs. Forty-five of 53 PCBs and BDEs 47, 100 and 154 had TMFs greater than one, suggesting their biomagnification in the present food web. The TMFs for PBDEs were generally smaller than those for PCBs with the same degree of halogenation, indicating a lower biomagnification potential for PBDEs compared to PCBs. For PCBs, it followed a parabolic relationship between TMFs and log K OW (octanol-water partition coefficient). However, this relationship was not significant for PBDEs, possibly due to the more complex behaviors of PBDEs in the food web (e.g., metabolism), compared to that of PCBs. - Forty-five of 53 PCBs magnified in the freshwater food web, while only BDEs 47, 100 and 154 significantly magnified in the same food web

Biomagnification of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls in a highly contaminated freshwater food web from South China

Energy Technology Data Exchange (ETDEWEB)

Wu Jiangping [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Luo Xiaojun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)], E-mail: luoxiaoj@gig.ac.cn; Zhang Ying; Yu Mei [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Chen Shejun; Mai Bixian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang Zhongyi [School of Life Sciences, SunYat-Sen University, Guangzhou 510275 (China)

2009-03-15

To evaluate the biomagnification extent of polybrominated diphenyls ethers (PBDEs) and polychlorinated biphenyls (PCBs) in a highly contaminated freshwater food web from South China, trophic magnification factors (TMFs) for 18 PBDE congeners and 53 PCB congeners were calculated. The TMF values ranged 0.26-4.47 for PBDEs and 0.75-5.10 for PCBs. Forty-five of 53 PCBs and BDEs 47, 100 and 154 had TMFs greater than one, suggesting their biomagnification in the present food web. The TMFs for PBDEs were generally smaller than those for PCBs with the same degree of halogenation, indicating a lower biomagnification potential for PBDEs compared to PCBs. For PCBs, it followed a parabolic relationship between TMFs and log K{sub OW} (octanol-water partition coefficient). However, this relationship was not significant for PBDEs, possibly due to the more complex behaviors of PBDEs in the food web (e.g., metabolism), compared to that of PCBs. - Forty-five of 53 PCBs magnified in the freshwater food web, while only BDEs 47, 100 and 154 significantly magnified in the same food web.

Temporal trend studies on tetra- and pentabrominated diphenyl ethers and hexabromocyclododecane in guillemot egg from the Baltic Sea.

Science.gov (United States)

Sellström, Ulla; Bignert, Anders; Kierkegaard, Amelie; Häggberg, Lisbeth; de Wit, Cynthia A; Olsson, Mats; Jansson, Bo

2003-12-15

Guillemot eggs from the Baltic Sea, sampled between 1969 and 2001, were analyzed for tetra- and pentabromodiphenyl ethers (2,2',4,4'-tetraBDE (BDE-47), 2,2',4,4',5-pentaBDE (BDE-99), and 2,2',4,4',6-pentaBDE (BDE-100)), and hexabromocyclododecane (HBCD). This temporal trend study indicates that the concentrations of the polybrominated diphenyl ether compounds increased from the 1970s to the 1980s, peaking around the mid- to the late-1980s. These peaks are then followed by a rapid decrease in concentrations during the rest of the study period, with the concentrations of the major BDE congener below 100 ng/g lipid weight at the end of the period. This corresponds to less than 10% of its peak values. The concentrations of HBCD show a different pattern over time. After a peak in the middle of the 1970s followed by a decrease, the concentrations increased during the latter part of the 1980s. During the recent 10-yr period no significant change has occurred, and the annual mean concentrations are more or less stable at a higher level as compared to the beginning of the study period.

Halogenated organics in Vietnamese and in Vietnam food. Dioxins, dibenzofurans, PCBs, polybrominated diphenyl ethers and selected pesticides

Energy Technology Data Exchange (ETDEWEB)

Schecter, A.; Tung, K.C. [Univ. of Texas School of Public Health at Dallas, TX (United States); Quynh, Hong Trong [Oncology Institute, Ha Noi, Vietnam (Viet Nam); Paepke, O. [ERGO Research Laboratory, Hamburg (Germany); Malisch, R. [State Laboratory for Chemical and Veterinary Analysis, Freiburg (Germany); Constable, J.D. [Harvard Medical School, Boston, MA (United States)

2004-09-15

Vietnam is frequently thought of as the location of the world's largest dioxin contamination, with over 400 pounds of 2,3,7,8-TCDD from Agent Orange defoliant sprayed from 1962 to 1971. Although this is true, distribution of dioxin from Agent Orange is far from ubiquitous in Vietnam. The north was never sprayed and only certain areas of central and south Vietnam were sprayed. Dioxins have been found in very high levels in human milk and in food in some select areas of Vietnam from the 1970s to the present. Other pesticides including DDT and metabolites, {alpha}, {beta}, and {gamma} HCH, and HCB have also been found in humans and in food. We review dioxin ''hot spots'' studied in the past with current suspect hot spots and also add to the chemicals studied in Vietnamese by measuring polybrominated diphenyl ether (PBDE) flame retardants in nursing Vietnamese women's milk and compare these to levels from other countries.

Polybrominated diphenyl ethers fate in China: a review with an emphasis on environmental contamination levels, human exposure and regulation.

Science.gov (United States)

Chen, Yuan; Li, Jinhui; Liu, Lili; Zhao, Nana

2012-12-30

Because of their highly effective flame-retardant capability, polybrominated diphenyl ethers (PBDEs) have been extensively used as flame retardants in consumer goods. However, compelling evidence shows that many congeners of PBDEs have been accumulating in the environment, in biota and in human populations worldwide. In China, although octabrominated diphenyl ether (octaBDE) has never been produced or used, pentabrominated diphenyl ether (pentaBDE) and decabrominated diphenyl ether (decaBDE) have been produced and used in large quantities. In the face of increasing evidence about PBDE pollution and the adoption of international conventions, there is a growing push for China to develop more stringent methods of managing PBDE waste. This paper summarizes the information about PBDE production and application, describes the flame-retarding mechanism, and then reviews the toxicity and levels of PBDEs in China's environmental media and human tissues. Based on international regulations on PBDEs, the paper finally puts forward some suggestions for Chinese policy making and for self-regulation within the flame retardant industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Decomposition of lignin model compounds by Lewis acid catalysts in water and ethanol

NARCIS (Netherlands)

Guvenatam, Burcu; Heeres, Erik H.J.; Pidko, Evgeny A.; Hensen, Emiel J. M.

2015-01-01

The conversion of benzyl phenyl ether, diphenyl ether, diphenyl methane and biphenyl as representative model compounds for alpha-O-4, 5-O-4, alpha(1) (methylene bridges) and 5-5' lignin linkages was investigated. We compared the use of metal chlorides and acetates. The reactions were studied in sub-

Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

Science.gov (United States)

Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

2009-01-16

Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

Organic halogen compounds in the environment

International Nuclear Information System (INIS)

1979-07-01

There are 20 research reports on selected problems concerning the analysis, the occurence, and the behaviour of a wide spectrum of organic halogen compounds. The work was carried out in the framework of the project 'Organic Halogen Compounds in the Environment', financed by the BMFT, between 1975 and 1978. (orig.) [de

Adsorption and sequential degradation of polybrominated diphenyl ethers with zerovalent iron

International Nuclear Information System (INIS)

Peng, Yu-Huei; Chen, Mei-kuei; Shih, Yang-hsin

2013-01-01

Highlights: • A detailed analysis in the removal mechanism of PBDEs by MZVI was conducted. • 13% of DBDE and 24% of BDE-3 in average were adsorbed on the surface of MZVI. • The adsorbed PBDEs on MZVI were also confirmed by FTIR spectroscopy. • MZVI continues the reductive debromination of PBDEs even after one month. •MZVI has great longevity to adsorb and degrade PBDE in the environment. -- Abstract: The widely used flame retardants, polybrominated diphenyl ethers (PBDEs), have been regulated owing to their persistence and toxicity. However, the high and increasing accumulation amount of PBDEs in the environment raises a big concern for public safety. In this study, the removal processes of decabromodiphenyl ether (BDE-209) and monobromodiphenyl ether (BDE-3) with microscale zerovalent iron (MZVI) were investigated to get better understandings for the removal mechanism based upon adsorption and degradation. The removal kinetics of both compounds was analyzed and revealed two-step kinetics: a fast removal step at the beginning of the reaction and a follow-up slow removal step. By-products generated during the entire process followed a stepwise sequence. The content of brominated compounds on the surface of MZVI was measured. About 10–20% of BDE-209 and 15–30% of BDE-3 were adsorbed on MZVI. The adsorption of BDE-209 and BDE-3 on MZVI was confirmed through the Fourier transform infrared spectroscopy. Surface adsorption of PBDEs on MZVI dominates the removal mechanism in the beginning and further debromination with MZVI was found. Finally, about 70% of BDE-209 and 60% of BDE-3 was degraded by MZVI within about one month. Our findings provide evidences for understanding the removal mechanism of PBDEs with MZVI and its great longevity on the PBDE degradation, which can facilitate the remediation design

An efficient synthesis of S-[gamma]-[(4-trifluoromethyl)phenoxy] benzenepropanamine-[1-[sup 14]C]maleate, an important metabolite of fluoxetine hydrochloride. [Antidepressant, serotonin uptake inhibitor

Energy Technology Data Exchange (ETDEWEB)

Wheeler, W.J. (Lilly (Eli) and Co., Indianapolis, IN (United States). Lilly Research Labs.)

1992-02-01

S-[gamma]-[(4-Trifluoromethyl)phenoxy]benzenepropanamine-[1-[sup 14]C] maleate has been prepared in six steps from R-(-)1-phenyl-1,2-ethanediol. The isotope was incorporated by the reaction of NaCN-[[sup 14]C] with the tert. butyldimethylsilyl ether of R-(-)1-phenyl-1,2-ethane-diol 2-tosylate. Borane reduction and arylation, followed by salt formation yielded S-[gamma]-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[1-[sup 14]C] maleate. (Author).

A study of oxidative stress induced by two polybrominated diphenyl ethers in the rotifer Brachionus plicatilis.

Science.gov (United States)

Zhang, Jing; Wang, You; Sun, Kai-Ming; Fang, Kuan; Tang, Xuexi

2016-12-15

Polybrominated diphenyl ethers (PBDEs) are widely dispersed persistent organic pollutants in the marine ecosystem. However, their toxic mechanisms in marine organisms, especially invertebrates, remain poorly understood. Two common congeners of PBDEs, tetrabrominated diphenyl ether-47 (BDE-47) and decabrominated diphenyl ether-209 (BDE-209), were investigated. Their toxic mechanisms, with a focus on oxidative stress, were examined in rotifer Brachionus plicatilis. Overproduction of reactive oxygen species (ROS) was induced by two PBDEs. The expression of superoxide dismutase (SOD) mRNA was increased, suggesting SOD play a main role in ROS-scavenging. The intercellular concentrations of calcium ([Ca 2+ ] in ) and the expression of calmodulin (CaM) mRNA were increased. This indicates the calcium ion (Ca 2+ ) signaling channel is involved in PBDEs stress. Further analysis showed that the reproductive system might be the target site for toxicity of PBDEs. Moreover, high value of detection indexes in BDE-47 experimental groups suggested BDE-47 might cause higher oxidative damage than BDE-209 in rotifers. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Exposure Assessment of Polybrominated Diphenyl Ethers ...

Science.gov (United States)

EPA announced the availability of the final report, An Exposure Assessment of Polybrominated Diphenyl Ethers. This report provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure. This final report addresses the exposure assessment needs identified in the OPBDE Workgroup project plan. It provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure.

Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

Energy Technology Data Exchange (ETDEWEB)

Zeng, Yan-Hong [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China); Luo, Xiao-Jun, E-mail: luoxiaoj@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Hua-Shan; Wu, Jiang-Ping; Chen, She-Jun; Mai, Bi-Xian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2012-05-15

A separation and isotopic analysis method was developed to accurately measure the stable carbon isotope ratios of polybrominated diphenyl ethers (PBDEs) with three to six substituted bromine atoms in fish samples. Sample extracts were treated with concentrated sulfuric acid to remove lipids, purified using complex silica gel column chromatography, and finally processed using alumina/silica (Al/Si) gel column chromatography. The purities of extracts were verified by gas chromatography and mass spectrometry (GC-MS) in the full-scan mode. The average recoveries of all compounds across the purification method were between 60% and 110%, with the exception of BDE-154. The stable carbon isotopic compositions of PBDEs can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . No significant isotopic fraction was found during the purification of the main PBDE congeners. A significant change in the stable carbon isotope ratio of BDE-47 was observed in fish carcasses compared to the original isotopic signatures, implying that PBDE stable carbon isotopic compositions can be used to trace the biotransformation of PBDEs in biota. - Highlights: Black-Right-Pointing-Pointer A method for the purification of PBDEs for CSIA was developed. Black-Right-Pointing-Pointer The {delta}{sup 13}C of PBDE congeners can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . Black-Right-Pointing-Pointer Common carp were exposed to a PBDE mixture to investigate debromination. Black-Right-Pointing-Pointer Ratios of the {delta}{sup 13}C values can be used to trace the debromination of PBDE in fish.

Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea.

Science.gov (United States)

Wang, Chao-Yi; Wang, Kai-Ling; Qian, Pei-Yuan; Xu, Ying; Chen, Min; Zheng, Juan-Juan; Liu, Min; Shao, Chang-Lun; Wang, Chang-Yun

2016-12-01

Marine organism-derived secondary metabolites are promising potential sources for discovering environmentally safe antifouling agents. In present study, 55 marine secondary metabolites and their synthesized derivatives were tested and evaluated for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds. The natural secondary metabolites, covering phenyl ether derivatives, terpenoids, 9, 11-secosteroids, anthraquinones, alkaloids, nucleoside derivatives and peptides, were isolated from two corals, one sponge and five symbiotic fungi. All of the isolated and synthesized compounds were tested for their antifouling activities against the cyprids of barnacle Balanus (Amphibalanus) amphitrite Darwin. Noticeably, five phenyl ether derivatives (9, 11, 13-15) exhibited potent anti-larval settlement activity with the EC 50 values lower than 3.05 μM and the LC 50 /EC 50 ratios higher than 15. The study of structure-activity relationship (SAR) revealed that the introduction of acetoxy groups and bromine atoms to phenyl ether derivatives could significantly improve their antifouling activities. This is the first report on the SAR of phenyl ether derivatives on antifouling activity against barnacle B. amphitrite. The polybrominated diphenyl ether derivative, 2, 4, 6, 2', 4', 6'-hexabromo-diorcinol (13), which displayed excellent antifouling activity, was considered as a promising candidate of environmentally friendly antifouling agents.

Photochemical Degradation of Polybrominated Diphenyl Ethers in Micro Photo-Reactor

Czech Academy of Sciences Publication Activity Database

Vajglová, Zuzana; Veselý, M.; Křišťál, Jiří; Vychodilová, Hana; Tříska, Jan; Jiřičný, Vladimír

2012-01-01

Roč. 42, SI (2012), s. 1378-1382 E-ISSN 1877-7058. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague, 25.08.2012-29.08.2012] R&D Projects: GA ČR GA104/09/0880 Institutional support: RVO:67985858 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * micro photo reactor * debromination Subject RIV: CI - Industrial Chemistry, Chemical Engineering

Concentrations and speciation of polybrominated diphenyl ethers in human amniotic fluid

Science.gov (United States)

Miller, Mark F.; Chernyak, Sergei M.; Domino, Steven E.; Batterman, Stuart A.; Loch-Caruso, Rita

2012-01-01

Polybrominated diphenyl ethers (PBDEs) are persistent organic chemicals used as flame retardants in textiles, plastics, and consumer products. Although PBDE accumulation in humans has been noted since the 1970s, few studies have investigated PBDEs within the gestational compartment, and none to date has identified levels in amniotic fluid. The present study reports congener-specific brominated diphenyl ether (BDE) concentrations in second-trimester clinical amniotic fluid samples collected in 2009 from fifteen women in southeast Michigan, USA. Twenty-one BDE congeners were measured by GC/MS/NCI. The average total PBDE concentration was 3795 pg/ml amniotic fluid (range: 337 – 21842 pg/ml). BDE-47 and BDE-99 were identified in all samples. Based on median concentrations, the dominant congeners were BDE-208, 209, 203, 206, 207, and 47 representing 23, 16, 12, 10, 9 and 6%, respectively, of the total detected PBDEs. PBDE concentrations were identified in all amniotic fluid samples from southeast Michigan, supporting a need for further investigations of fetal exposure pathways and potential impacts on perinatal health. PMID:22236635

Synthesis and physicochemical properties of polyhydroxylated diphenyl ethers

Energy Technology Data Exchange (ETDEWEB)

Liu, Fu; Zhang, Xuesheng; Qu, Ruijuan; Shi, Jiaqi; Wang, Zunyao, E-mail: wangzun315cn@163.com

2013-09-20

Highlights: • The experimental pK{sub a1} values of five synthesized PHODEs were determined. • The hydrogen bonds existed in PHODEs were investigated. • There exist close relationships between the thermodynamic properties and N{sub PHOS}. • The relative stability order of PHODE congeners was theoretically proposed. - Abstract: Five polyhydroxylated diphenyl ethers (PHODEs) were synthesized. The first ionization constants (pK{sub a1}) of the synthesized compounds and seven phenolic compounds were determined using potentiometric titration experiments, together with the software ACD/Labs pK{sub a} DB program (version 6.0). The compared results showed that the software could be used to predict the pK{sub a1} of all 209 PHODEs. The thermodynamic properties of 209 PHODEs were calculated using density functional theory (DFT) at the B3LYP/6-311G** level with Gaussian 09 program. The standard enthalpy of formation (Δ{sub f}H{sup θ}) and the standard Gibbs energy of formation (Δ{sub f}G{sup θ}) were obtained. Two types of hydrogen bond were found to exist in the PHODEs’ molecules. The intramolecular hydrogen bond energies were discussed. The relative stability of PHODEs isomers was proposed theoretically with the relative standard Gibbs energy of formation (Δ{sub f}G{sub R}{sup θ}). The relationships of S{sup θ}, Δ{sub f}H{sup θ} and Δ{sub f}G{sup θ} to the number and position of the hydroxyl substitution (N{sub PHOS}) were studied.

Simultaneous Determination of Methoxylated Polybrominated Diphenyl Ethers and Polybrominated Diphenyl Ethers in Water, Soil and Sediment from China by GC-MS.

Science.gov (United States)

Hu, Xiaozhong; Hu, Decong; Chen, Wei; Wu, Bin; Lin, Changjun

2015-09-01

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants, which are increasingly reported in the environment. Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are structural analogs to PBDEs and reported as natural products and novel pollutants present in the environment. First, a new isotopic dilution GC-MS method was developed in this study to simultaneously determine 13 PBDEs and 8 MeO-PBDEs in water, soil and sediment. Liquid/liquid extraction, pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, and some important steps and crucial parameters were modified and intensified compared with the other literatures. Besides, the conditions of GC and MS were also optimized. The limits of quantitation values of 0.005-0.1 and 0.02-0.1 µg L(-1) in water were calculated for PBDEs and MeO-PBDEs, respectively; so did 0.25-5 and 1-5 µg kg(-1) dry weight in soil and sediment. In addition, good repeatability and accuracy of the whole method were achieved. Moreover, 60 water and 30 sediment samples for aquaculture crayfish and freshwater fish collected from aquatic products production base, 40 soil samples collected from agricultural products production base and also 20 Yangtze River water samples and 20 Hanjiang River water samples collected from different sampling situations near Wuhan, Hubei province along the Yangtze River and the Hanjiang River were analyzed to determine whether they are contaminated by PBDEs and MeO-PBDEs. Using the established methods, it was found that PBDEs or MeO-PBDEs emerged in 4 of 60 water samples for aquatic products, 3 of 40 soils, and 2 of 30 sediments and in low µg kg(-1) dry weight for soil and sediments and low µg L(-1) for water. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Determination of average molecular weights on organic reactor coolants. II.-Freezing point depression method for diphenyl-ether solutions

International Nuclear Information System (INIS)

Carreira, M.

1965-01-01

In order to reduce limitations of solubility, the cryoscopic method developed for benzene solutions of polyphenyl mixtures has been extended to diphenyl-ether solutions by introducing some modifications imposed by the physico-chemical properties of this solvent. The Nernsto theory of Beckman's method has been revised, taking into account the heat-transfer characteristics of the system, and the results of that analysis have been used to fix upon the design parameters of a cryoscopic apparatus for measurements on diphenyl-ether solutions. (Author) 9 refs

An assessment of sources and pathways of human exposure to polybrominated diphenyl ethers in the United States.

Science.gov (United States)

Johnson-Restrepo, Boris; Kannan, Kurunthachalam

2009-07-01

Polybrominated diphenyl ethers (PBDEs) are ubiquitous in the indoor environment, owing to their use in consumer products ranging from electronics to mattresses, furniture, and carpets. People are exposed to PBDEs through inhalation of indoor air and ingestion, and dermal absorption of dust particles present in the air. In this study, concentrations of PBDEs were determined in indoor air and house dust collected from homes in Albany, New York, USA. Based on the measured concentrations of PBDEs in indoor air and dust, we estimated daily exposure dose (DED) of PBDEs. In addition, we used previously published PBDE concentrations reported for breast milk from Massachusetts, USA [Johnson-Restrepo, B., Addink, R., Wong, C., Arcaro, K., Kannan, K., 2007. Polybrominated diphenyl ethers and organochlorine pesticides in human breast milk from Massachusetts. USA. J. Environ. Monitor. 9, 1205-1212] and foodstuffs collected from Texas and Florida, USA [Schecter, A., Päpke, O., Harris, T.R., Tung, K.C., Musumba, A., Olson, J., Birnbaum, L., 2006. Polybrominated diphenyl ether (PBDE) levels in an expanded market basket survey of U.S. food and estimated PBDE dietary intake by age and sex. Environ. Health Perspect. 114, 1515-1520, Johnson-Restrepo, B., Kannan, K., Addink, R., Adams, D.H., 2005b. Polybrominated diphenyl ethers and polychlorinated biphenyls in a marine foodweb of coastal Florida. Environ. Sci. Technol. 39, 8243-8250], in an estimation of dietary exposure to PBDEs. The exposure assessment was performed for five age groups: infants (accounting for, on average, 56-77% of the total PBDE intake.

Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea

KAUST Repository

Wang, Chao-Yi

2016-10-26

Marine organism-derived secondary metabolites are promising potential sources for discovering environmentally safe antifouling agents. In present study, 55 marine secondary metabolites and their synthesized derivatives were tested and evaluated for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds. The natural secondary metabolites, covering phenyl ether derivatives, terpenoids, 9, 11-secosteroids, anthraquinones, alkaloids, nucleoside derivatives and peptides, were isolated from two corals, one sponge and five symbiotic fungi. All of the isolated and synthesized compounds were tested for their antifouling activities against the cyprids of barnacle Balanus (Amphibalanus) amphitrite Darwin. Noticeably, five phenyl ether derivatives (9, 11, 13–15) exhibited potent anti-larval settlement activity with the EC50 values lower than 3.05 μM and the LC50/EC50 ratios higher than 15. The study of structure–activity relationship (SAR) revealed that the introduction of acetoxy groups and bromine atoms to phenyl ether derivatives could significantly improve their antifouling activities. This is the first report on the SAR of phenyl ether derivatives on antifouling activity against barnacle B. amphitrite. The polybrominated diphenyl ether derivative, 2, 4, 6, 2′, 4′, 6′-hexabromo-diorcinol (13), which displayed excellent antifouling activity, was considered as a promising candidate of environmentally friendly antifouling agents.

Polybrominated diphenyl ethers in indoor air in Kuwait: Implications for human exposure

Science.gov (United States)

Gevao, Bondi; Al-Bahloul, Majed; Al-Ghadban, Abdul Nabi; Ali, Lulwa; Al-Omair, Ali; Helaleh, Murad; Al-Matrouk, Khaled; Zafar, Jamal

Polyurethane foam plug passive samplers were used to concurrently measure air concentrations of polybrominated diphenyl ethers (PBDEs) in 70 indoor environments. PBDEs were detected in all homes and offices investigated with patterns similar to the distribution in the commercial penta technical formulation (Bromkal 70-5DE). The ubiquitous distribution of these compounds in indoor environments may be due to the volatilization of these chemicals from foam (e.g. mattresses, foam padded furniture), electronic equipments (e.g. TVs, printers, computers) and other consumer products to which they are added as flame retardants. Mean ΣPBDEs concentration in air was log-normally distributed and ranged from ˜2-385 pg m -3. Using an inhalation rate of 8 and 20 m 3 day -1 for children and adults respectively, exposure via inhalation is estimated to be 173 and 399 pg day -1 for children and adults respectively. This study supports the growing body of evidence for the ubiquitous presence of these compounds in indoor air and the potential for continuous, low-level exposure both at work and home.

Combined effects of dissolved humic acids and tourmaline on the accumulation of 2, 2', 4, 4', 5, 5'- hexabrominated diphenyl ether (BDE-153) in Lactuca sativa.

Science.gov (United States)

Wang, Cuiping; Ma, Chuanxin; Jia, Weili; Wang, Dong; Sun, Hongwen; Xing, Baoshan

2017-12-01

In order to investigate the effects of dissolved humic acid (DHA) and tourmaline on uptake of 2, 2', 4, 4', 5, 5'- hexabrominated diphenyl ether (BDE-153) by Lactuca sativa, different fractions of DHA, including DHA 1 and DHA 4 , as well as different doses of tourmaline were introduced into BDE-153 contaminated solutions for plant growth. The levels of BDE-153 in L. sativa tissues were positively correlated with the Fe levels (R 2  = 0.9264) in seedings of the treatments with different doses of tourmaline. However, when adding DHA 1 and DHA 4 into the system, the correlation coefficients (R 2 ) decreased to 0.6976 and 0.5451 from 0.9264, respectively. In contrast with the Fe contents, the presence of DHAs didn't affect the R 2 between the levels of BDE-153 and the lipid contents in plant tissues. Our results indicated that both DHA 1 and DHA 4 could severely alter the BDE-153 uptake by L. sativa through reducing the Fe uptake instead of the lipid contents. Additionally, DHA 4 exhibited much stronger abilities to alter the BDE-153 accumulation than DHA 1 . Transmission electron microscopy (TEM) observations indicated that either DHA 1 or tourmaline or co-treatment with DHA and tourmaline had no negative impact on L. sativa at the cellular level. The present study provides important information for the impacts of different fractions of DHA extracted from soil on the BDE-153 migration in plant systems. Moreover, we elucidated the importance of the iron in tourmaline for migration of the polybrominated diphenyl ethers (PBDEs) in plant systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl 4-methylbenzenesulfonoselenoate

Directory of Open Access Journals (Sweden)

Clément Ghiazza

2017-12-01

Full Text Available Herein the nucleophilic addition of Se-(trifluoromethyl 4-methylbenzenesulfonoselenoate, a stable and easy-to-handle reagent, to alkynes is described. This reaction provides trifluoromethylselenylated vinyl sulfones with good results and the method was extended also to higher fluorinated homologs. The obtained compounds are valuable building blocks for further syntheses of fluoroalkylselenolated molecules.

Improved debromination of polybrominated diphenyl ethers by bimetallic iron–silver nanoparticles coupled with microwave energy

International Nuclear Information System (INIS)

Luo, Si; Yang, Shaogui; Sun, Cheng; Gu, Ji-Dong

2012-01-01

This study focused on the enhanced debromination of decabromodiphenyl ether (BDE-209) and 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by Fe–Ag nano-particles under microwave radiation (Fe–Ag/MW). Fe–Ag bimetallic nano-particles were synthesized by reductive deposition of Ag on nano-iron and characterized with a number of techniques, including BET, XRD, TEM and XPS. Approximately 97% of BDE-209 or 78% of BDE-47 were rapidly transformed to its degradation products within 8 min in the Fe–Ag/MW system. The dehalogenation efficiency of polybrominated diphenyl ethers (PBDEs) was enhanced apparently by microwave radiation. Moreover, the microwave thermal energy played a significant role in accelerating the degradation reactions. Compared with nano-iron alone, the deposition of Ag also increased the rates of degradation. GC–MS and LC–MS/MS analyses of PBDEs' degradation products reveals that the possible degradation pathway proceeds through stepwise debromination from [n]-bromo- to [n-1]-bromo-DE, with bromine being substituted by hydrogen sequentially. Di- to nona-brominated congeners were formed during BDE-209 reduction, while diphenyl ether to tri-BDEs were observed during BDE-47 degradation. These results suggest that PBDEs can be debrominated rapidly by the innovative processes that may be environmentally friendly in applications. - Highlights: ► The Fe–Ag nanoparticles with a core–shell structure were successfully prepared. ► A highly efficient technology for debromination of PBDEs by Fe–Ag/MW was investigated. ► The effect of bromine's number on the stability against reduction of PBDEs was explored. ► The role of MW energy and Ag in the reactivity of the Fe–Ag/MW system was demonstrated. ► The possible degradation pathways of BDE-209 and BDE-47 were proposed.

Improved debromination of polybrominated diphenyl ethers by bimetallic iron-silver nanoparticles coupled with microwave energy

Energy Technology Data Exchange (ETDEWEB)

Luo, Si [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Yang, Shaogui, E-mail: yangdlut@126.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Sun, Cheng, E-mail: envidean@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Gu, Ji-Dong [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

2012-07-01

This study focused on the enhanced debromination of decabromodiphenyl ether (BDE-209) and 2,2 Prime ,4,4 Prime -tetrabromodiphenyl ether (BDE-47) by Fe-Ag nano-particles under microwave radiation (Fe-Ag/MW). Fe-Ag bimetallic nano-particles were synthesized by reductive deposition of Ag on nano-iron and characterized with a number of techniques, including BET, XRD, TEM and XPS. Approximately 97% of BDE-209 or 78% of BDE-47 were rapidly transformed to its degradation products within 8 min in the Fe-Ag/MW system. The dehalogenation efficiency of polybrominated diphenyl ethers (PBDEs) was enhanced apparently by microwave radiation. Moreover, the microwave thermal energy played a significant role in accelerating the degradation reactions. Compared with nano-iron alone, the deposition of Ag also increased the rates of degradation. GC-MS and LC-MS/MS analyses of PBDEs' degradation products reveals that the possible degradation pathway proceeds through stepwise debromination from [n]-bromo- to [n-1]-bromo-DE, with bromine being substituted by hydrogen sequentially. Di- to nona-brominated congeners were formed during BDE-209 reduction, while diphenyl ether to tri-BDEs were observed during BDE-47 degradation. These results suggest that PBDEs can be debrominated rapidly by the innovative processes that may be environmentally friendly in applications. - Highlights: Black-Right-Pointing-Pointer The Fe-Ag nanoparticles with a core-shell structure were successfully prepared. Black-Right-Pointing-Pointer A highly efficient technology for debromination of PBDEs by Fe-Ag/MW was investigated. Black-Right-Pointing-Pointer The effect of bromine's number on the stability against reduction of PBDEs was explored. Black-Right-Pointing-Pointer The role of MW energy and Ag in the reactivity of the Fe-Ag/MW system was demonstrated. Black-Right-Pointing-Pointer The possible degradation pathways of BDE-209 and BDE-47 were proposed.

The characterization of electroplex generated from the interface between 2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazole] zinc and N,N'-diphenyl-N,N'- bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine

Science.gov (United States)

Zhang, Ye; Hao, Yuying; Meng, Weixin; Xu, Huixia; Wang, Hua; Xu, Bingshe

2012-03-01

The electroplex between (2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazole) zinc [Zn(4-TfmBTZ)2] as an electron-acceptor and N,N'-diphenyl-N,N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB) as an electron-donor was characterized by bilayer, blend, and multilayer quantum-well (MQW) device, respectively. The blend composition and quantum-well number are effective parameters for tuning electroluminescence color. White light with high color purity and color rendering index (CRI) was observed from these devices based on Zn(4-TfmBTZ)2/NPB. Moreover, the blend and MQW devices all exhibit high operation stability, hence excellent color stability. For the device with 5 mol% NPB in blend layer, its Commission International Del'Eclairage (CIE) coordinate region is x=0.28-0.31, y=0.33-0.35 and CRI is 83.3-91.2 at 5-9 V. For MQW structure device with NPB of 60 nm thickness, its CIE coordinate region is x=0.29-0.32, y=0.31-0.34 and CRI=87.9-92.5 at 10-15 V. Such high color stability and purity and CRI, being close to ideal white light, are of current important for white OLED.

Measurement of polybrominated diphenyl ethers in environmental matrix standard reference materials

Energy Technology Data Exchange (ETDEWEB)

Stapleton, H.; Schantz, M.; Wise, S. (National Institute of Standards and Technology)

2004-09-15

Polybrominated diphenyl ethers (PBDEs) are a class of emerging contaminants of concern as many studies have now demonstrated that these compounds are bioaccumulative, persistent and increasing in concentration in the environment. PBDEs are being detected in almost every environmental sample examined, and they have even been measured in samples collected in the Arctic, further demonstrating their persistence and potential for long range transport. More and more studies are continuing to examine the fate and transport of these flame retardant compounds in environmental samples and as such, reference materials are needed to provide quality control on these measurements. The National Institute of Standards and Technology (NIST) supports a national Standard Reference Material (SRM) program for measurement of organic contaminants such as PCBs, PAHs and chlorinated pesticides in environmental matrices. This current study was undertaken to provide reference measurements for PBDEs in selected SRMs that are currently used by various laboratories throughout the United States. These SRMs include matrices such as marine mammal blubber, lake trout tissue, mussel tissue, sediment, house dust and human serum. We report here reference values for 22 PBDE congeners that have been quantified in these seven types of SRMs.

Polybrominated Diphenyl Ethers and Perfluoroalkyl Substances in Serum of Pregnant Women

DEFF Research Database (Denmark)

Vorkamp, Katrin; Nielsen, Flemming; Kyhl, Henriette Boye

2014-01-01

Polybrominated diphenyl ethers (PBDEs), a group of flame retardants, and perfluoroalkyl substances (PFASs) were analysed in serum samples of pregnant women from Denmark to provide information about their exposure and to study indications of common exposure pathways. The main BDE congener was the ...... of exposure and/or pharmacokinetic and metabolisation processes. PBDE and PFAS concentrations were in the range associated with adverse effects in some epidemiological studies....

Global occurrence of polybrominated diphenyl ethers and their hydroxylated and methoxylated structural analogues in an important animal feed (fishmeal).

Science.gov (United States)

Li, Xiaomin; Dong, Shujun; Zhang, Wei; Fan, Xia; Li, Yang; Wang, Ruiguo; Su, Xiaoou

2018-03-01

Polybrominated diphenyl ethers (PBDEs) and their hydroxylated (OH) and methoxylated (MeO) structural analogues have been found widely distributed in aquatic ecosystems, and may exhibit potential adverse effects to humans due to their bioaccumulative behavior through food chain. Fishmeal is an important animal feed applied around the world and is generally of marine origin. However, the levels and sources of PBDEs in fishmeal have not been thoroughly evaluated and their structural analogues have not been reported to date. The present study collected ninety-two fishmeal samples from world main fishmeal producing area to determine 27 PBDEs, 10 MeO-PBDEs and 11 OH-PBDEs. The concentrations of Σ 27 PBDEs, Σ 10 MeO-PBDEs and Σ 11 OH-PBDEs were in the ranges of 0.1-1498 (mean: 75.8), 1.14-881 (37.4) and 1.00-47.5 (8.17) ng/g lipid, respectively. PBDEs were found primarily correlated with the historically commercial production, meaning higher production of certain commercial product in a country, higher corresponding PBDE congeners in local fishmeal. A market shift from penta- and octa-formulations toward deca-formulation was observed. BDE209 was identified as a major congener in fishmeal. Both the MeO-PBDEs and the OH-PBDEs were influenced by fishmeal producing areas (p 1 in the northern hemisphere and <1 in the southern hemisphere in the present study, which was consistent with the results obtained from previous published papers. Both MeO-PBDEs and OH-PBDEs were in accordance with the specialties of naturally produced halogenated compounds. Copyright © 2017. Published by Elsevier Ltd.

Trifluoromethyl acting as stopper in [2]rotaxane

KAUST Repository

Dasgupta, Suvankar; Huang, Kuo-Wei; Wu, Jishan

2012-01-01

A modified dumbbell obtained by replacing one of the phenyl groups of the dibenzylammonium with a strong electron-withdrawing trifluoromethyl group templated the synthesis of the smallest [2]rotaxane reported so far. The trifluoromethyl group not only enhances the templating effect of the dumbbell but also acts as the stopper to prevent dethreading of a [20]crown ether macrocycle. © 2012 The Royal Society of Chemistry.

Trifluoromethyl acting as stopper in [2]rotaxane

KAUST Repository

Dasgupta, Suvankar

2012-07-24

A modified dumbbell obtained by replacing one of the phenyl groups of the dibenzylammonium with a strong electron-withdrawing trifluoromethyl group templated the synthesis of the smallest [2]rotaxane reported so far. The trifluoromethyl group not only enhances the templating effect of the dumbbell but also acts as the stopper to prevent dethreading of a [20]crown ether macrocycle. © 2012 The Royal Society of Chemistry.

Biomagnification and debromination of polybrominated diphenyl ethers in a coastal ecosystem in Tokyo Bay

Energy Technology Data Exchange (ETDEWEB)

Mizukawa, Kaoruko; Yamada, Toshiko [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Matsuo, Hiroaki; Takeuchi, Ichiro [Department of Life Environment Conservation, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, Ehime 790-8566 (Japan); Tsuchiya, Kotaro [Faculty of Marine Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477 (Japan); Takada, Hideshige, E-mail: shige@cc.tuat.ac.jp [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

2013-04-01

By field sampling and laboratory experiments we compared the mechanisms by which polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are biomagnified. We measured PBDEs and PCBs, together with stable carbon and nitrogen isotopes as an index of trophic level, in low-trophic-level organisms collected from a coastal area in Tokyo Bay. PBDEs were biomagnified to a lesser degree than PCBs. The more hydrophobic congeners of each were biomagnified more. However, the depletion of BDE congeners BDE99 and BDE153 from fish was suggested. To study congener-specific biotransformation of halogenated compounds, we conducted an in vitro experiment using hepatic microsomes of two species of fish and five BDE congeners (BDE47, 99, 100, 153, and 154) and five CB congeners with the same substitution positions as the PBDEs. BDE99 and 153 were partially debrominated, but BDE47 and 154 were not debrominated. This congener-specific debromination is consistent with the field results. Both in vitro and field results suggested selective debromination at the meta position. The CB congeners were not transformed in vitro. This result is also consistent with the field results, that PCBs were more biomagnified than PBDEs. We conclude that metabolizability is an important factor in the biomagnification of chemicals, but other factors must be responsible for the lower biomagnification of PBDEs in natural ecosystems. Highlights: ► PBDEs were less biomagnified than PCBs in low-trophic-level organisms in Tokyo Bay. ► Depletion of PBDE congeners BDE99 and BDE153 from fish was suggested. ► BDE99 and 153 were debrominated in in vitro experiment using hepatic microsomes of fish. ► BDE47, 100, and 154 as well as PCB congeners were not transformed in vitro. ► Both in vitro and field results suggested selective meta-protonation of PBDEs.

Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

Energy Technology Data Exchange (ETDEWEB)

Yen, J H; Liao, W C; Chen, W C [Department of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Wang, Y.S., E-mail: yswang@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)

2009-06-15

The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 {mu}g/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

International Nuclear Information System (INIS)

Yen, J.H.; Liao, W.C.; Chen, W.C.; Wang, Y.S.

2009-01-01

The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 μg/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

A brominated flame retardant 2,2',4,4' tetrabrominated diphenyl ether (BDE-47) leads to lipogenesis in the copepod Tigriopus japonicus.

Science.gov (United States)

Lee, Min-Chul; Han, Jeonghoon; Lee, Seung-Hwi; Kim, Duck-Hyun; Kang, Hye-Min; Won, Eun-Ji; Hwang, Dae-Sik; Park, Jun Chul; Om, Ae-Son; Lee, Jae-Seong

2016-09-01

De novo lipogenesis (DNL) is a fatty acid synthesis process that requires several genes, including sterol regulatory element binding protein (SREBP), ATP-citrate lyase (ACLY), and acetyl-CoA carboxylase (ACC). DNL up-regulation is able to induce fat accumulation through an increase in fatty acids. To investigate the relationship between DNL up-regulation and the accumulation of fatty acids and lipid droplets in response to 2,2',4,4' tetrabrominated diphenyl ether (BDE-47), we examined DNL in the copepod Tigriopus japonicus. Transcription levels of DNL-related genes were increased after exposure to 2.5μg/L BDE-47 for 24h. After exposure to 2.5μg/L BDE-47, palmitic acid was significantly increased (Pcopepod. This study provides a better understanding of the effects of BDE-47 on DNL in copepods. Copyright © 2016 Elsevier B.V. All rights reserved.

Possible mechanisms of thyroid hormone disruption in mice by BDE 47, a major polybrominated diphenyl ether congener

International Nuclear Information System (INIS)

Richardson, Vicki M.; Staskal, Daniele F.; Ross, David G.; Diliberto, Janet J.; DeVito, Michael J.; Birnbaum, Linda S.

2008-01-01

Polybrominated diphenyl ethers (PBDEs) are a class of polyhalogenated aromatic compounds commercially used as fire retardants in consumer products. These compounds have been shown to decrease thyroid hormone concentrations in rodents after acute exposures. This study examines the ability of 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) to decrease circulating thyroid hormone concentrations and pairs this with BDE 47-induced effects on genes involved in thyroid hormone homeostasis. Female C57BL/6 mice (9 weeks old) were orally administered 3, 10, or 100 mg/kg/day of BDE 47 for 4 days. Animals were euthanized 24 h after the final dose (day 5) and liver, kidney, and serum were collected for analysis. BDE 47 caused a significant 43% decrease at 100 mg/kg/day in serum total thyroxine (T 4 ) concentrations. There was no increase in hepatic T 4 -glucuronidation activity, but significant increases in hepatic Ugt1a1, Ugt1a7, and Ugt2b5 mRNA expression accompany significant decreases in T 4 concentrations at 100 mg/kg/day of BDE 47. Induction of PROD activity occurred at the lowest dose (3 mg/kg/day). Cyp2b10 mRNA expression also increased significantly at 10 and 100 mg/kg/day. These key findings show that BDE activates the nuclear receptor, CAR. Decreases in Mdr1a mRNA expression also occurred at the lowest dose administered (3 mg/kg/day BDE 47). BDE 47 exposure also decreased hepatic transthyretin and monocarboxylate transporter 8 (Mct8) mRNA expression, suggesting that while induction of UGTs may be partly responsible for T 4 decreases, other mechanisms are also involved. No effects were seen in the kidney. We conclude that changes in hepatic UGTs and transporters may be involved in decreases in circulating T 4 following BDE 47 exposure

Polybrominated diphenyl ether flame retardants in Virginia freshwater fishes (USA).

Science.gov (United States)

Hale, R C; La Guardia, M J; Harvey, E P; Mainor, T M; Duff, W H; Gaylor, M O

2001-12-01

Polybrominated diphenyl ethers (PBDEs) were examined in fish fillets collected from two large Virginia watersheds. Emphasis was on the tetra- to hexabrominated congeners since these exhibit the greatest bioaccumulation and toxicological potentials. These congeners are dominant constituents of Penta-, a commercial PBDE product used to flame retard polyurethane foam. In 1999, North America accounted for98% of global Penta-demand. Concentrations of total tetra- to hexabrominated congeners in fillets ranged from furniture and textile manufacturing, although polyurethane foam production here has been limited.

Global Gridded Emission Inventories of Pentabrominated Diphenyl Ether (PeBDE)

Science.gov (United States)

Li, Yi-Fan; Tian, Chongguo; Yang, Meng; Jia, Hongliang; Ma, Jianmin; Li, Dacheng

2010-05-01

Polybrominated diphenyl ethers (PBDEs) are flame retardants widely used in many everyday products such as cars, furniture, textiles, and other electronic equipment. The commercial PBDEs have three major technical mixtures: penta-(PeBDE), octa-(OBDE) and decabromodiphenyl ethers (DeBDE). PeBDE is a mixture of several BDE congeners, such as BDE-47, -99, and -100, and has been included as a new member of persistent organic pollutants (POPs) under the 2009 Stockholm Convention. In order to produce gridded emission inventories of PeBDE on a global scale, information of production, consumption, emission, and physiochemical properties of PeBDE have been searched for published papers, government reports, and internet publications. A methodology to estimate the emissions of PeBDE has been developed and global gridded emission inventories of 2 major congener in PeBDE mixture, BDE-47 and -99, on a 1 degree by 1degree latitude/longitude resolution for 2005 have been compiled. Using these emission inventories as input data, the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP) model was used to simulate the transport of these chemicals and their concentrations in air were calculated for the year of 2005. The modeled air concentration of BDE-47 and -99 were compared with the monitoring air concentrations of these two congeners in the same year obtained from renowned international/national monitoring programs, such as Global Atmospheric Passive Sampling (GAPS), the Integrated Atmospheric Deposition Network (IADN), and the Chinese POPs Soil and Air Monitoring Program (SAMP), and significant correlations between the modeled results and the monitoring data were found, indicating the high quality of the produced emission inventories of BDE-47 and -99. Keywords: Pentabrominated Diphenyl Ether (PeBDE), Emission Inventories, Global, Model

Polybrominated Diphenyl Ether Exposure and Thyroid Function Tests in North American Adults.

Science.gov (United States)

Makey, Colleen M; McClean, Michael D; Braverman, Lewis E; Pearce, Elizabeth N; He, Xue-Mei; Sjödin, Andreas; Weinberg, Janice M; Webster, Thomas F

2016-04-01

Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals that are added to many consumer products. Multiple animal studies have shown PBDEs to be thyroid hormone (TH) disruptors. Epidemiologic evidence of PBDE exposure associated with TH disruption has been inconclusive. We used repeated measures to estimate associations between serum PBDE concentrations and THs in a North American adult cohort. From 2010 to 2011, we collected ≤ 3 serum samples at approximately 6-month intervals from 52 healthy adult office workers from Boston, Massachusetts, for analysis of PBDE congeners and THs. The geometric mean sum concentrations of the most prevalent PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, and BDE-153) were 22 ng/g lipid in winter 2010, 23 ng/g lipid in summer 2010, and 19 ng/g lipid in winter 2011. BDE-47 was the predominant congener. Based on a multivariable mixed regression model, we estimated that on average, a 1-ng/g serum increase in BDE-47 was associated with a 2.6-μg/dL decrease in total thyroxine (T4) (95% CI: -4.7, -0.35). Total T4 was inversely associated with each PBDE congener. Serum concentrations of PBDEs were not strongly associated with total triiodothyronine (T3), free T4, or thyroid-stimulating hormone (TSH). These results are consistent with those from animal studies showing that exposure to PBDEs is associated with a decrease in serum T4. Because the other TH concentrations did not appear to be associated with BDE exposures, our findings do not indicate effects on the pituitary-thyroid axis. Taken together, our findings suggest that PBDE exposure might decrease the binding of T4 to serum T4 binding proteins. Makey CM, McClean MD, Braverman LE, Pearce EN, He XM, Sjödin A, Weinberg JM, Webster TF. 2016. Polybrominated diphenyl ether exposure and thyroid function tests in North American adults. Environ Health Perspect 124:420-425; http://dx.doi.org/10.1289/ehp.1509755.

Effects of a diphenyl-ether herbicide, oxyfluorfen, on human BFU-E/CFU-E development and haemoglobin synthesis.

Science.gov (United States)

Rio, B; Parent-Massin, D; Lautraite, S; Hoellinger, H

1997-02-01

The diphenyl-ether herbicides exert their phytotoxic activity by preventing chlorophyll formation in plants as a result of inhibition of protoporphyrinogen oxidase. This enzyme is the last step of the common pathway for chlorophyll and haem biosynthesis. The aim of this work is to determine whether herbicide inhibitors of plant protoporphyrinogen oxidase could act on the human protoporphyrinogen oxidase involved in haemoglobin synthesis and cause heamatologic diseases. Human erythroblastic progenitors (BFU-E/CFU-E: Burst Forming Unit-Erythroid and Colony Forming Unit-Erythroid) were exposed to oxyfluorfen, a diphenyl-ether herbicide in the presence of erythropoietin, and the haematoxicity evaluated in vitro by scoring the development of BFU-E/CFU-E colonies after 7 and 14 days of culture. The toxic effect on differentiation has been evaluated using four criteria: morphology, total protein, total porphyrin, and haemoglobin content. The study of BFU-E/CFU-E proliferation and differentiation showed a cytotoxic effect of oxyfluorfen only at very high concentrations. In contrast, haemoglobin synthesis can be inhibited by concentration of oxyfluorfen (10(-4) M) that have no adverse effect on cellular proliferation.

Formation of hydroxylated polybrominated diphenyl ethers from laccase-catalyzed oxidation of bromophenols.

Science.gov (United States)

Lin, Kunde; Zhou, Shiyang; Chen, Xi; Ding, Jiafeng; Kong, Xiaoyan; Gan, Jay

2015-11-01

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been frequently found in the marine biosphere as emerging organic contaminants. Studies to date have suggested that OH-PBDEs in marine biota are natural products. However, the mechanisms leading to the biogenesis of OH-PBDEs are still far from clear. In this study, using a laccase isolated from Trametes versicolor as the model enzyme, we explored the formation of OH-PBDEs from the laccase-catalyzed oxidation of simple bromophenols (e.g., 2,4-DBP and 2,4,6-TBP). Experiments under ambient conditions clearly showed that OH-PBDEs were produced from 2,4-DBP and 2,4,6-TBP in presence of laccase. Polybrominated compounds 2'-OH-BDE68, 2,2'-diOH-BB80, and 1,3,8-TrBDD were identified as the products from 2,4-DBP, and 2'-OH-BDE121 and 4'-OH-BDE121 from 2,4,6-TBP. The production of OH-PBDEs was likely a result of the coupling of bromophenoxy radicals, generated from the laccase-catalyzed oxidation of 2,4-DBP or 2,4,6-TBP. The transformation of bromophenols by laccase was pH-dependant, and was also influenced by enzymatic activity. In view of the abundance of 2,4-DBP and 2,4,6-TBP and the phylogenetic distribution of laccases in the environment, laccase-catalyzed conversion of bromophenols may be potentially an important route for the natural biosynthesis of OH-PBDEs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs).

Science.gov (United States)

Cantón, Rocío F; Scholten, Deborah E A; Marsh, Göran; de Jong, Paul C; van den Berg, Martin

2008-02-15

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC(50) values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K(i)/K(i)' of 7.68/0,02 microM and 5.01/0.04 microM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a

Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs)

International Nuclear Information System (INIS)

Canton, Rocio F.; Scholten, Deborah E.A.; Marsh, Goeran; Jong, Paul C. de; Berg, Martin van den

2008-01-01

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC 50 values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K i /K i ' of 7.68/0,02 μM and 5.01/0.04 μM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a wide

Fate of polybrominated diphenyl ethers during cooking of fish in a new model cooking apparatus and a household microwave.

Science.gov (United States)

Bendig, Paul; Hägele, Florian; Blumenstein, Marina; Schmidt, Jasmin; Vetter, Walter

2013-07-10

Fish is a major source of human exposure to polybrominated diphenyl ethers (PBDEs). Because fish is mainly consumed after cooking, this measure may alter the pattern and amounts of PBDEs that are finally consumed. To investigate this issue, we developed a model cooking apparatus consisting of a small glass bowl and a beaker glass with an exhaust fitted with a polyurethane foam filter connected to a water jet pump. In this model cooking apparatus, fish (1 g) and/or sunflower oil (0.2/0.4 g) spiked with three PBDE congeners was cooked for 30 min. Small amounts of the semi-volatile PBDEs were evaporated from the fish (BDE-47 cooking apparatus proved to be well-suited to study the fate of polyhalogenated compounds in fish during cooking.

Concentration of polybrominated diphenyl ethers (PBDEs) in sediment cores of Sundarban mangrove wetland, northeastern part of Bay of Bengal (India)

International Nuclear Information System (INIS)

Binelli, Andrea; Sarkar, Santosh Kumar; Chatterjee, Mousumi; Riva, Consuelo; Parolini, Marco; Bhattacharya, Bhaskar deb; Bhattacharya, Asok Kumar; Satpathy, Kamala Kanta

2007-01-01

The paper presents the first comprehensive survey of congener profiles (12 congeners) of polybrominated diphenyl ethers (PBDEs) in core sediment samples ( 12 PBDE values ranging from 0.08 to 29.03 ng g -1 , reflecting moderate to low contamination closely in conformity to other Asian aquatic environments. The general order of decreasing congener contribution to the total load was: BDE 47 > 99 > 100 > 154, similar to the distribution pattern worldwide. Although tetrabromodiphenyl ether BDE 47 was found in all samples followed by hexabromodiphenyl ether BDE-154, they were not necessarily the dominant congeners. No uniform temporal trend on PBDE levels was recorded probably due to particular hydrological characteristics of the wetland and/on non-homologous inputs from point sources (untreated municipal wastewater and local industries, electronic wastes from the dump sites, etc.) of these compounds. Because of the propensity of PBDEs to accumulate in various compartments of wildlife and human food webs, evaluation of biological tissues should be undertaken as a high priority

Poly-brominated diphenyl-ethers (PBDEs) and other persistent organic pollutants in blood of penguins from the Ross Sea (Antarctica)

Energy Technology Data Exchange (ETDEWEB)

Corsolini, S.; Ademollo, N.; Mariottini, M.; Focardi, S. [Universita degli Studi di Siena, Siena (Italy)

2004-09-15

Polychlorobiphenyls (PCBs), hexachlorobenzene (HCB), polybrominated diphenyl ethers (PBDEs) and dichlorodiphenyl-dichloro ethane (pp'-DDE) including its isomers and metabolites are known as POPs very well. POPs are particularly hazardous to wildlife not only because they are toxic but because they are persistent and distributed on global scale. Polybrominated diphenyl ethers (PBDEs) are a class of POPs used worldwide as flame retardants with an increasing trend in the market demand (67.4 ktons in 2001), but with some restrictions in their usage in Europe. PBDEs are hydrophobic, highly soluble in lipids, resistant to biodegradation and have similar behavior to polychlorinated biphenyls (PCBs) in aquatic and terrestrial ecosystems. Their bioaccumulation and biomagnification properties, as well their global increasing presence, have already been reported by many authors. PBDEs have been detected in remote Arctic regions10 that seem to be their final sink. PBDEs show acute toxicity and a prolonged exposure can affect the function of thyroid and cause neurodevelopmental disorders and estrogenic and hepatic effects. Furthermore, a synergic effect with dioxin-like compounds or other POPs cannot be excluded. The two aims of this study are: (1) to evaluate accumulation levels and patterns of PCBs, PBDEs and chlorinated pesticides in blood samples of the Adelie penguin, Pygoscelis adeliae, the Emperor penguin, Aptenodytes forsteri and the South Polar skua, Cataracta maccormicki from three sites in the Ross Sea (Antarctica); (2) to assess the suitability of blood for the detection of POP residues in supposedly low contaminated organisms that live in protected/ecologically sensitive areas.

Phthalates and polybrominated diphenyl ethers in retail stores

Science.gov (United States)

Xu, Ying; Liang, Yirui; Urquidi, Jorge R.; Siegel, Jeffrey A.

2014-04-01

Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories, because they are extensively used as additives in consumer products and associated with serious health concerns. This study measured six phthalate and 14 PBDE compounds inside of 12 retail stores in Texas and Pennsylvania, U.S. Phthalates and PBDEs were widely found in the retail environment, indicating that they are ubiquitous indoor air pollutants. DEP, DnBP, and DEHP were the most abundant phthalates, with DnBP showing the highest concentration (0.23 ± 0.36 μg m-3). PBDEs were dominated by BDE-28, -99, and -209, having concentrations as high as 0.85 ± 1.99 ng m-3 (BDE-99). The levels of phthalates and PBDEs measured in this study are comparable to concentrations found in previous investigations of residential buildings, with phthalates showing lower concentrations and PBDEs exhibiting higher concentrations in retail stores. The potential co-occurrence of phthalates was not as strong as that of PBDEs, suggesting that phthalates might have more diverse sources. Whole building emission rates were calculated and showed similar patterns of variations as indoor air concentrations, suggestion the diversity of indoor sources of phthalates and PBDEs in retail environments.

A National Probabilistic Study of Polybrominated Diphenyl Ethers in Fish from US Lakes and Reservoirs

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National estimates were developed for polybrominated diphenyl ethers (PBDEs) in fish from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake) using an unequal probability design. Predator (fillet) and bottom-dweller (w...

Design and synthesis of novel insecticides based on the serotonergic ligand 1-[(4-aminophenyl)ethyl]-4-[3-(trifluoromethyl)phenyl]piperazine (PAPP).

Science.gov (United States)

Cai, Mingyi; Li, Zhong; Fan, Feng; Huang, Qingchun; Shao, Xusheng; Song, Gonghua

2010-03-10

1-[(4-Aminophenyl)ethyl]-4-[3-(trifluoromethyl)phenyl]piperazine (PAPP) is a 5-HT(1A) agonist and was reported to display high affinity for serotonin (5-HT) receptor from the parasitic nematode Haemonchus contortus . The present investigation explored the possibility of using PAPP as a lead compound of new insecticides with novel mode of action. On the basis of the PAPP scaffold, a series of 1-arylmethyl-4-[(trifluoromethyl)pyridin-2-yl]piperazine derivatives were designed, synthesized, and evaluated for biological activities against the armyworm Pseudaletia separata (Walker). Bioassays showed that most of the target compounds displayed certain growth-inhibiting activities or larvicidal activities against armyworm. The quantitative structure-activity relationship (QSAR) for growth-inhibiting activities was also analyzed and established.

Antidepressant-like effect of m-trifluoromethyl-diphenyl diselenide in the mouse forced swimming test involves opioid and serotonergic systems.

Science.gov (United States)

Brüning, César Augusto; Souza, Ana Cristina Guerra; Gai, Bibiana Mozzaquatro; Zeni, Gilson; Nogueira, Cristina Wayne

2011-05-11

Serotonergic and opioid systems have been implicated in major depression and in the action mechanism of antidepressants. The organoselenium compound m-trifluoromethyl-diphenyl diselenide (m-CF(3)-PhSe)(2) shows antioxidant and anxiolytic activities and is a selective inhibitor of monoamine oxidase A activity. The present study was designed to investigate the antidepressant-like effect of (m-CF(3)-PhSe)(2) in female mice, employing the forced swimming test. The involvement of the serotonergic and opioid systems in the antidepressant-like effect of (m-CF(3)-PhSe)(2) was appraised. (m-CF(3)-PhSe)(2) at doses of 50 and 100mg/kg (p.o.) exhibited antidepressant-like action in the forced swimming test. The effect of (m-CF(3)-PhSe)(2) (50mg/kg p.o.) was prevented by pretreatment of mice with WAY100635 (0.1mg/kg, s.c. a selective 5-HT(1A) receptor antagonist), ritanserin (4 mg/kg, i.p., a non-selective 5HT(2A/2C) receptor antagonist), ondansetron (1mg/kg, i.p., a selective 5-HT(3) receptor antagonist) and naloxone (1mg/kg, i.p., a non-selective antagonist of opioid receptors). These results suggest that (m-CF(3)-PhSe)(2) produced an antidepressant-like effect in the mouse forced swimming test and this effect seems most likely to be mediated through an interaction with serotonergic and opioid systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Transformation of 2,2′,4,4′-tetrabromodiphenyl ether under UV irradiation: Potential sources of the secondary pollutants

International Nuclear Information System (INIS)

Wang, Ji-Zhong; Hou, Yuqing; Zhang, Jianshun; Zhu, Jiping; Feng, Yong-Lai

2013-01-01

Highlights: • 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) was found transformed to six less brominated BDE analogs under UV irradiation. • BDE-47 was found degraded faster in liquid phase than in gas phase. • Two brominated phenols were formed in the transformation of BDE-47 in gas phase. • The bromine on the ortho positions of the phenyl rings was found lost first to form 2,4,4′-tribromodiphenyl ether (BDE-28). • The more volatile less brominated BDEs are a source of secondary pollutants in the environment. -- Abstract: A commercial brominated flame retardant 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) was used as the model chemical to investigate the degradation and transformation of polybrominated diphenyl ethers (PBDEs) in gas and liquid phases, respectively, under ultraviolet (UV) irradiation. The results showed that BDE-47 can be transformed to less-brominated BDE analogs. A total of six compounds that are less-brominated BDEs and two brominated phenols were observed as transformation products in the reaction mixtures. Different degradation rates of BDE-47 in n-nonane and in isooctane in the same chamber system were observed. Degradation rate of BDE-47 in n-nonane was faster than in isooctane. Under UV irradiation, the bromine on the ortho positions of the phenyl rings was lost first to form 2,4,4′-tribromodiphenyl ether (BDE-28), which then progressively lead to 4,4′-dibromodiphenyl ether (BDE-15) or 2,4′-dibromodiphenyl ether (BDE-8). An airborne transformation pathway has been proposed according to observed transformation products. The more volatile less-brominated BDEs from transformation of BDE-47 are easily evaporated into air to be a source of secondary pollutants in the environment

Polybrominated diphenyl ethers in articles: a review of its applications and legislation.

Science.gov (United States)

Jinhui, Li; Yuan, Chen; Wenjing, Xiao

2017-02-01

Polybrominated diphenyl ethers (PBDEs), especially commercial decabrominated diphenyl ethers (c-decaBDE), have been widely produced and applied to numerous materials because of their highly effective flame-retardant capabilities. The production of commercial pentaBDE (c-pentaBDE) and commercial octaBDE (c-octaBDE) ended in 2004 because they are persistent, bioaccumulative, and toxic to both humans and the environment, but decaBDE production and use continue. Furthermore, many congeners of PBDEs are still prevalent in consumer products and articles that they pose enormous threat to both the environment and human health. PBDEs have been detected in the casing of electrical and electronic equipment, textile materials, automotive interiors, polyurethane foam (PUF) in seat cushions, children's toys, kitchenware, and other products. With increasing evidence about PBDE pollution and the adoption of international conventions, many developed countries have drawn more public attention to PBDEs and developed sound strategies for their management. This review summaries the utilization and management of PBDEs in a number of countries and reaches the conclusion that PBDEs are still prevalent in consumer articles, while specific regulations or policies for articles containing PBDEs are rare. Public awareness should be raised on the importance of sound management of articles containing PBDEs.

Levels and distribution of polybrominated diphenyl ethers in Three Gorges Reservoir, China

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Jingxian Wang

2017-03-01

Full Text Available Polybrominated diphenyl ethers (PBDEs were investigated in water, sediments, suspended sediments and biofilms in Three Gorges Reservoir (TGR, China. Results showed that dissolved bioavailable PBDEs in water of TGR collected with semipermeable membrane device (SPMD-based virtual organisms (VOs were very low in the range of n.d. to 811 pg/g lipid and the detected compounds were mainly low molecular BDEs such as BDE-15, 17, 28, 47, 49, 66, 99 and 100. The PBDE levels in the sediment core collected near the dam were also very low in the range of 84–300 pg/g dw and the detected compounds were mainly large molecular BDEs such as BDE-196, 197, 206, 207 and 208. In suspended sediments and biofilms, the levels of PBDEs ranged from 298 to 52,843 pg/g dw and the detected compounds were also mainly large molecular BDEs such as BDE- 196, 197, 201, 203, 206, 207, 208 and 209. The dominant compound was BDE-209 which accounted for more than 90% of the total BDEs. Therefore, large molecular BDEs tended to be attached on fine particles. The vertical profile of BDEs on suspended sediments (SS showed that SSs in the middle depth of water contained high level of BDE-209. The phenomenon indicated that most of BDE-209 did not settle into the sediment in front of the dam, instead transported further to downstream.

Flourimetric and prototropic studies on the inclusion complexation of 2-amino and 4-aminodiphenyl ethers with {beta}-cyclodextrin: Unusual behavior of 4-aminodiphenyl ether

Energy Technology Data Exchange (ETDEWEB)

Enoch, Israel V. Muthu Vijayan [Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu (India); Swaminathan, Meenakshisundaram [Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu (India)], E-mail: chemsam@yahoo.com

2007-12-15

The fluorescence characteristics of diphenyl ether (DPE), 2-aminodiphenyl ether (2ADPE) and 4-aminodiphenyl ether (4ADPE) and prototropic behavior of 2ADPE and 4ADPE on inclusion complexation with {beta}-cyclodextrin have been investigated. DPE forms 1:1 complex whereas 2ADPE and 4ADPE form 1:2 complex with {beta}-CDx. The fluorimetric and prototropic behaviors of 4ADPE in {beta}-CDx are different from those in aqueous solution. The dual fluorescence of 4ADPE in {beta}-CDx is found to be due to twisted intramolecular charge transfer (TICT) character induced by inclusion complexation. The two equilibria viz. monocation{r_reversible}monocation solvent exciplex{r_reversible}neutral reported for 4ADPE in aqueous solution are not observed in presence of {beta}-CDx. The ground and excited state pK{sub a} values for monocation-neutral equilibrium of 2ADPE and 4ADPE have been reported.

Polybrominated diphenyl ethers: a case study for using biomonitoring data to address risk assessment questions.

Science.gov (United States)

Birnbaum, Linda S; Cohen Hubal, Elaine A

2006-11-01

The use of biomonitoring data holds promise for characterizing exposure and informing risk assessment. Biomonitoring data have been used successfully to track population trends, identify susceptible populations, and provide indications of emerging environmental health issues. However, there remain challenges associated with interpreting biomonitoring data for risk assessment. An international biomonitoring workshop was convened in September 2004 to explore the use of biomonitoring data in the context of risk assessment. Six compounds were examined as case studies for this workshop, including polybrominated diphenyl ethers (PBDEs). The PBDE case study was developed to provide an example of a persistent compound for which relatively few data are available for human exposure, biomonitoring, and health outcomes. PBDEs are used in hard plastics, electronics, textiles, and polyurethane foam products. The congener pattern downstream of production facilities often resembles the commercial mixture. However, because these compounds persist in the environment and in biota, the patterns of congeners evolve. PBDEs partition into body lipids, and direct measurement of bromodiphenyl ether congeners in biologic specimens provides a good marker of exposure. Data indicate significant variability (> 100-fold range) in lipid-adjusted levels for PBDEs in the general population. It is hypothesized that both exposure and pharmacokinetics may play a role in observed congener profiles. Significant gaps in our ability to interpret PBDE biomonitoring data to address public health and risk assessment questions include limited knowledge of environmental fate and transport of PBDE congeners, limited population-based data for adults, and lack of data for potentially vulnerable populations such as children.

QSPR models of n-octanol/water partition coefficients and aqueous solubility of halogenated methyl-phenyl ethers by DFT method.

Science.gov (United States)

Zeng, Xiao-Lan; Wang, Hong-Jun; Wang, Yan

2012-02-01

The possible molecular geometries of 134 halogenated methyl-phenyl ethers were optimized at B3LYP/6-31G(*) level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for predicting aqueous solubility (-lgS(w,l)) and n-octanol/water partition coefficient (lgK(ow)) of halogenated methyl-phenyl ethers. The two models achieved in this work both contain three variables: energy of the lowest unoccupied molecular orbital (E(LUMO)), most positive atomic partial charge in molecule (q(+)), and quadrupole moment (Q(yy) or Q(zz)), of which R values are 0.992 and 0.970 respectively, their standard errors of estimate in modeling (SD) are 0.132 and 0.178, respectively. The results of leave-one-out (LOO) cross-validation for training set and validation with external test sets both show that the models obtained exhibited optimum stability and good predictive power. We suggests that two QSPR models derived here can be used to predict S(w,l) and K(ow) accurately for non-tested halogenated methyl-phenyl ethers congeners. Copyright © 2011 Elsevier Ltd. All rights reserved.

Simple and fast analysis of tetrabromobisphenol A, hexabromocyclododecane isomers, and polybrominated diphenyl ethers in serum using solid-phase extraction or QuEChERS extraction followed by tandem mass spectrometry coupled to HPLC and GC.

Science.gov (United States)

Li, Jian; Chen, Tian; Wang, Yuwei; Shi, Zhixiong; Zhou, Xianqing; Sun, Zhiwei; Wang, Dejun; Wu, Yongning

2017-02-01

Two simplified sample preparation procedures for simultaneous extraction and clean-up of tetrabromobisphenol A, α-, β-, and γ-hexabromocyclododecane and polybrominated diphenyl ethers in human serum were developed and validated. The first procedure was based on solid-phase extraction. Sample extraction, purification, and lipid removal were carried out directly on an Oasis HLB cartridge. The second procedure was a quick, easy, cheap, effective, rugged, and safe-based approach using octadecyl-modified silica particles as a sorbent. After sample extraction and cleanup, tetrabromobisphenol A/hexabromocyclododecane was separated from polybrominated diphenyl ethers by using a Si-based cartridge. Tetrabromobisphenol A and hexabromocyclododecane were then detected by high-performance liquid chromatography coupled to tandem mass spectrometry, while polybrominated diphenyl ethers were detected by gas chromatography coupled to tandem mass spectrometry. The results of the spike recovery test using fetal bovine serum showed that the average recoveries of the analytes ranged from 87.3 to 115.3% with relative standard deviations equal to or lower than 13.4 %. Limits of detection of the analytes were in the range of 0.4-19 pg/mL except for decabromodiphenyl ether. The developed method was successfully applied to routine analysis of human serum samples from occupational workers and the general population. Extremely high serum polybrominated diphenyl ethers levels up to 3.32 × 10 4 ng/g lipid weight were found in occupational workers. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Leaching characteristics of polybrominated diphenyl ethers (PBDEs) from flame-retardant plastics.

Science.gov (United States)

Kim, Yong-Jin; Osako, Masahiro; Sakai, Shin-ichi

2006-10-01

To investigate the effect of leachant on the leachability of polybrominated diphenyl ethers (PBDEs), we determined the leaching concentrations of PBDEs from flame-retardant plastic samples (TV housings and raw materials before molding processing) that are regarded as a source of PBDEs in landfill sites. The leachants used were distilled water, 20% methanol solution, and dissolved humic solution (DHS) of 1000 mg/l based on organic carbon. The leaching test conditions were a liquid-to-solid ratio of 100:1, and a contact period of five days, with twice-daily agitation in a temperature-controlled room of 30 degrees C without pH or ionic strength control. The leaching concentrations of PBDEs increased with increased content, and were found to be remarkably enhanced when methanol and DHS were used instead of distilled water. The enhancement of leachability in the presence of the latter was attributed to the cosolvency effect, and complex formations between the PBDEs and dissolved humic matter (DHM). PBDE concentrations in the leachate obtained from the leaching test and an actual landfill site revealed a significant presence of congeners below heptabromodiphenyl ethers (H7BDEs), detected in the leachate of the actual landfill, while significant amounts of nonabromodiphenyl ethers (N9BDEs) and decabromodiphenyl ether (D10BDE) were detected in the leachate of the leaching test.

Uptake of polybrominated diphenyl ethers by carrot and lettuce crops grown in compost-amended soils.

Science.gov (United States)

Bizkarguenaga, E; Iparraguirre, A; Oliva, E; Quintana, J B; Rodil, R; Fernández, L A; Zuloaga, O; Prieto, A

2016-02-01

The uptake of polybrominated diphenyl ethers (PBDEs) by carrot and lettuce was investigated. Degradation of PBDEs in soil in the absence of the plants was discarded. Different carrot (Nantesa and Chantenay) and lettuce (Batavia Golden Spring and Summer Queen) varieties were grown in fortified or contaminated compost-amended soil mixtures under greenhouse conditions. After plant harvesting, roots (core and peel) and leaves were analyzed separately for carrot, while for lettuce, leaves and hearts were analyzed together. The corresponding bioconcentration factors (BCFs) were calculated. In carrots, a concentration gradient of 2,2',3,4,4',5'-hexabromodiphenyl ether (BDE-138) became evident that decreased from the root peel via root core to the leaves. For decabromodiphenyl ether (BDE-209) at the low concentration level (7 and 20 ng g(-1)), the leaves incorporated the highest concentration of the target substance. For lettuce, a decrease in the BCF value (from 0.24 to 0.02) was observed the higher the octanol-water partition coefficient, except in the case of BDE-183 (BCF = 0.51) and BDE-209 (BCF values from 0.41 to 0.74). Significant influence of the soils and crop varieties on the uptake could not be supported. Metabolic debromination, hydroxylation or methylation of the target PBDEs in the soil-plant system was not observed.

Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

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Barbara Palka

2014-07-01

Full Text Available A straightforward synthesis of 6-substituted 1-phenyl-3-trifluoromethyl-1H-pyrazolo[4,3-c]pyridines and the corresponding 5-oxides is presented. Hence, microwave-assisted treatment of 5-chloro-1-phenyl-3-trifluoromethylpyrazole-4-carbaldehyde with various terminal alkynes in the presence of tert-butylamine under Sonogashira-type cross-coupling conditions affords the former title compounds in a one-pot multicomponent procedure. Oximes derived from (intermediate 5-alkynyl-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehydes were transformed into the corresponding 1H-pyrazolo[4,3-c]pyridine 5-oxides by silver triflate-catalyzed cyclization. Detailed NMR spectroscopic investigations (1H, 13C, 15N and 19F were undertaken with all obtained products.

Maternal-infant transfer of polybrominated diphenyl ethers

Energy Technology Data Exchange (ETDEWEB)

Hirai, T.; Fujimine, Y.; Watanabe, S. [Otsuka Pharmaceutical Co., Ltd., Tokushima (Japan); Nakamura, Y. [SRL Nishinihon, Fukuoka (Japan); Shimomura, H. [Shimomura OBGY Clinic, Fukuoka (Japan); Nagayama, J. [Kyushu Univ., Fukuoka (Japan)

2004-09-15

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants (BFRs) in plastics of automobiles, textile industry, television, personal computer, electronic appliances etc. The amount of production world-wide has reached 40,000 tons in 1992. In 1992 world-wide production of PBDEs reached 40,000 tons raising serious concern over the dangers of environmental pollution by BFRs. The toxicity of PBDEs was reported to be an antagonist of thyroid-hormone (T4) and inhibition to aryl hydrocarbon (Ah) receptor. Since PBDEs are structurally similar to PCBs and therefore they work as an antagonist. Polychlorinated biphenyl (PCBs) demonstrate biological stability and high lipophilicity. As a result, PCBs used in the past and released into the environment, have been transmitted through the food chain and accumlated in the human body over time. In Japan, approximately 58,000 tons of PCBs were produced with the grade name of Kanechlor in between 1954 and 1971. In this study, all PCB congeners and 25 PBDE congeners (17, 25, 28, 30, 32, 33, 35, 37, 47, 49, 66, 71, 75, 77, 85, 99, 100, 116, 119, 126, 138, 153, 154, 155, 166) were analyzed by the method that combines high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The purpose of this study was to investigate whether congener-specific PCBs and PBDEs were transferred from pregnant women to their infants.

Determination and prediction of octanol-air partition coefficients of hydroxylated and methoxylated polybrominated diphenyl ethers.

Science.gov (United States)

Zhao, Hongxia; Xie, Qing; Tan, Feng; Chen, Jingwen; Quan, Xie; Qu, Baocheng; Zhang, Xin; Li, Xiaona

2010-07-01

The octanol-air partition coefficient (K(OA)) of 19 hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and 10 methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were measured as a function of temperature using a gas chromatographic retention time technique. At room temperature (298.15K), log K(OA) ranged from 8.30 for monobrominated OH/MeO-PBDEs to 13.29 for hexabrominated OH/MeO-PBDEs. The internal energies of phase change from octanol to air (Delta(OA)U) for 29 OH/MeO-PBDE congeners ranged from 72 to 126 kJ mol(-1). Using partial least-squares (PLS) analysis, a statistically quantitative structure-property relationship (QSPR) model for logK(OA) of OH/MeO-PBDE congeners was developed based on the 16 fundamental quantum chemical descriptors computed by PM3 Hamiltonian, for which the Q(cum)(2) was about 0.937. The molecular weight (Mw) and energy of the lowest unoccupied molecular orbital (E(LUMO)) were found to be main factors governing the log K(OA). 2010 Elsevier Ltd. All rights reserved.

Flame retardant synergism between molybdenum and halogen-containing compounds in unsaturated polyesters. [Smoke suppression

Energy Technology Data Exchange (ETDEWEB)

Skinner, G.A.; Parker, L.E.; Marshall, P.J.

1978-01-01

Oxygen index results for a series of unsaturated polyesters, containing molybdenum oxide and various halogenated compounds, have provided definite evidence for some form of flame retardant synergistic effect between molybdenum and halogen. With the halogenated compounds used, the magnitude of the effect was greater in the presence of bromine but was dependent on the type of compound. When dibromoneopentyl glycol was used as the bromine source, the synergistic effect exhibited by molybdenum oxide was comparable to that shown by antimony oxide. Since molybdenum oxide also acts as a smoke suppressant, it could offer a useful alternative to antimony oxide particularly in the light of probable changes in standards and regulatory control regarding smoke emission. 4 figures, 2 tables.

Cs2CO3-Initiated Trifluoro-Methylation of Chalcones and Ketones for Practical Synthesis of Trifluoromethylated Tertiary Silyl Ethers

Directory of Open Access Journals (Sweden)

Cheng Dong

2017-05-01

Full Text Available It was found that 1,2-trifluoromethylation reactions of ketones, enones, and aldehydes were easily accomplished using the Prakash reagent in the presence of catalytic amounts of cesium carbonate, which represents an experimentally convenient, atom-economic process for this anionic trifluoromethylation of non-enolisable aldehydes and ketones.

Radiolytic decomposition of 4-bromodiphenyl ether

International Nuclear Information System (INIS)

Tang Liang; Xu Gang; Wu Wenjing; Shi Wenyan; Liu Ning; Bai Yulei; Wu Minghong

2010-01-01

Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of e sol - in the reduction system was measured at 2.7 x 10 10 L · mol -1 · s -1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing e sol - in radiolytic process. (authors)

In vivo metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in young whole pumpkin plant.

Science.gov (United States)

Sun, Jianteng; Liu, Jiyan; Yu, Miao; Wang, Chang; Sun, Yuzhen; Zhang, Aiqian; Wang, Thanh; Lei, Zhen; Jiang, Guibin

2013-04-16

Polybrominated diphenyl ethers (PBDEs) are widely distributed persistent organic pollutants. In vitro and in vivo research using various animal models have shown that PBDEs might be transformed to hydroxylated PBDEs, but there are few studies on in vivo metabolism of PBDEs by intact whole plants. In this research, pumpkin plants (Cucurbita maxima × C. moschata) were hydroponically exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). A debromination product (BDE-28) and four hydroxylated metabolites (5-OH-BDE-47, 6-OH-BDE-47, 4'-OH-BDE-49, and 4-OH-BDE-42) were detected in different parts of the whole plant. In addition, 4-methoxylated-2,2',3,4'-tetraBDE (4-MeO-BDE-42) was observed as a methoxylation product. Root exudates in solution were found to play an important role in metabolizing BDE-47 to a specific OH-PBDE: 4'-OH-BDE-49. BDE-28 was found to translocate more easily and accumulate in shoots than BDE-47 due to the lower hydrophobicity and molecular weight. The concentration ratio between metabolites and parent compound BDE-47 was lower for OH-PBDEs than that for both BDE-28 and 4-MeO-BDE-42. The metabolism pathway of BDE-47 in young whole plants was proposed in this study.

Absorption and translocation of polybrominated diphenyl ethers (PBDEs) by plants from contaminated sewage sludge

Czech Academy of Sciences Publication Activity Database

Vrkoslavová, J.; Demnerová, K.; Macková, M.; Zemanová, T.; Macek, Tomáš; Hajšlová, J.; Pulkrabová, J.; Hrádková, P.; Stiborová, H.

2010-01-01

Roč. 81, č. 3 (2010), s. 381-386 ISSN 0045-6535 R&D Projects: GA MŠk 2B06151 Grant - others:GA ČR(CZ) GP104/08/P188 Institutional research plan: CEZ:AV0Z40550506 Keywords : polybrominated diphenyl ethers * contaminated sewage sludge * plant uptake * bioconcentration factors * Nicotiana tabacum Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.155, year: 2010

Process for removing halogenated aliphatic and aromatic compounds from petroleum products

Science.gov (United States)

Googin, J.M.; Napier, J.M.; Travaglini, M.A.

1983-09-20

A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

Reductive debromination of polybrominated diphenyl ethers in anaerobic sediment and a biomimetic system.

Science.gov (United States)

Tokarz, John A; Ahn, Mi-Youn; Leng, June; Filley, Timothy R; Nies, Loring

2008-02-15

Because of the bioaccumulation of penta- and tetrapolybrominated diphenyl ether (PBDE) flame retardants in biota,the environmental biotransformation of decabromodiphenyl ether (BDE-209) is of interest. BDE-209 accounts for more than 80% by mass of PBDE production and is the dominant PBDE in sediments. Most sediments are anaerobic and reports of microbial reductive dehalogenation of hydrophobic persistent organohalogen pollutants are numerous. Reductive debromination of BDE-209 in the environment could provide a significant source of lesser-brominated PBDEs to biota. Moreover, a recent study showed that BDE-209 debrominates in sewage sludge, and another demonstrated that some halorespiring bacteria will debrominate BDE-209. To determine whether reductive debromination of BDE-209 occurs in sediments, parallel experiments were conducted using anaerobic sediment microcosms and a cosolvent-enhanced biomimetic system. In the biomimetic system, reductive debromination occurred at rates corresponding to bromine substitution levels with a BDE-209 half-life of only 18 s compared with a halflife of almost 60 days for 2,2',4,4'-tetrabromodiphenyl ether. In sediment, the measured debromination half-life of BDE-209 was well over a decade and was in good agreement with the predicted value obtained from the biomimetic experiment. Product congeners were predominantly double para-substituted. BDE-209 debrominated in sediment with a corresponding increase in nona-, octa-, hepta-, and hexa-PBDEs. Nine new PBDE congeners appeared in sediment from reductive debromination. Given the very large BDE-209 burden already in sediments globally, it is important to determine whether this transformation is a significant source of lesser-brominated PBDEs to the environment.

Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

International Nuclear Information System (INIS)

Elhadi, S. A.

2004-09-01

Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, 1 H-and 13 C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

Energy Technology Data Exchange (ETDEWEB)

Elhadi, S A [Department of Chemistry, Faculty of Education, University of Khartoum, Khartoum (Sudan)

2004-09-01

Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, {sup 1}H-and {sup 13}C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

IRIS Health Assessment of 2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47) CASRN 5436-43-12,2',4,4',5-Pentabromodiphenyl Ether (BDE-99) CASRN 60348-60-92,2',4,4',5,5'-Hexabromodiphenyl Ether (BDE-153) CASRN 68631-49-22,2',3,3',4,4',5,5',6,6'-Decabromodiphenyl Ether (BDE-209) CASRN 1163-19-5

Science.gov (United States)

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam (pentaBDE), plastics for TV cabinets, consumer electronics, wire insulation, and backcoatings for draperies and upholstery (decaBDE), and plastics for personal computers and small appliances (oc...

Contamination of U.S. butter with polybrominated diphenyl ethers from wrapping paper.

Science.gov (United States)

Schecter, Arnold; Smith, Sarah; Colacino, Justin; Malik, Noor; Opel, Matthias; Paepke, Olaf; Birnbaum, Linda

2011-02-01

Our aim was to report the first known incidence of U.S. butter contamination with extremely high levels of polybrominated diphenyl ethers (PBDEs). Ten butter samples were individually analyzed for PBDEs. One of the samples and its paper wrapper contained very high levels of higher-brominated PBDEs. Dietary estimates were calculated using the 2007 U.S. Department of Agriculture Loss-Adjusted Food Availability data, excluding the elevated sample. The highly contaminated butter sample had a total upper bound PBDE level of 42,252 pg/g wet weight (ww). Levels of brominated diphenyl ether (BDE)-206, -207, and -209 were 2,000, 2,290, and 37,600 pg/g ww, respectively. Its wrapping paper contained a total upper-bound PBDE concentration of 804,751 pg/g ww, with levels of BDE-206, -207, and -209 of 51,000, 11,700, and 614,000 pg/g, respectively. Total PBDE levels in the remaining nine butter samples ranged from 180 to 1,212 pg/g, with geometric mean of 483 and median of 284 pg/g. Excluding the outlier, total PBDE daily intake from all food was 22,764 pg/day, lower than some previous U.S. dietary intake estimates. Higher-brominated PBDE congeners were likely transferred from contaminated wrapping paper to butter. A larger representative survey may help determine how frequently PBDE contamination occurs. Sampling at various stages in food production may identify contamination sources and reduce risk.

Levels of polybrominated diphenyl-ethers and polybrominated dioxins in fish, total diet study food groups, and Japanese meals

Energy Technology Data Exchange (ETDEWEB)

Ashizuka, Y.; Nakagawa, R.; Hori, T.; Tobiishi, K.; Iida, T. [Fukuoka Inst. of Health and Environmental Sciences, Dazaifu (Japan)

2004-09-15

Since they were found in mother's milk and blood in several studies, the polybrominated diphenyl-ethers (PBDEs) and other polybrominated flame-retardants (BFRs) that are used in plastics, electrical appliances, and textiles have been recognized as ubiquitous pollutants. BFRs are precursors of polybrominated dibenzo-p-dioxins/ polybrominated dibenzofurans (PBDD/Fs). Recently, 2,3,7,8-TBDD/Fs and PBDEs have been detected in adipose tissue and blood in Japanese people. Food is naturally suspected. However, there is very few information on food contamination with those brominated compounds in Japan. Therefore, we measured the levels of PBDEs and PBDD/Fs in various fish samples, meal samples, and total diet study (TDS) food groups and estimated Japanese people's dietary intake of PBDD/Fs and PBDEs.

A one-pot synthesis of 3-trifluoromethyl-2-isoxazolines from trifluoromethyl aldoxime

Directory of Open Access Journals (Sweden)

Raoni S. B. Gonçalves

2013-11-01

Full Text Available Functionalized 3-trifluoromethyl-2-isoxazolines and 3-trifluoromethylisoxazoles were easily prepared from trifluoromethyl aldoxime 2 under mild conditions by using DIB as oxidant. Theoretical studies of the reactivity of trifluoroacetonitrile oxide 4 toward olefins and alkynes were carried out. The 3-trifluoromethyl-2-isoxazolines were ring-opened with NaBH4 and NiCl2 to yield the corresponding trifluoromethylated γ-amino alcohols.

Trifluoromethanesulfonic Anhydride as a Low-Cost and Versatile Trifluoromethylation Reagent.

Science.gov (United States)

Ouyang, Yao; Xu, Xiu-Hua; Qing, Feng-Ling

2018-04-19

A large number of reagents have been developed for the synthesis of trifluoromethylated compounds. However, an ongoing challenge in trifluoromethylation reaction is the use of less expensive and practical trifluoromethyl sources. We report herein the unprecedented direct trifluoromethylation of (hetero)arenes using trifluoromethanesulfonic anhydride as a radical trifluoromethylation reagent by merging photoredox catalysis and pyridine activation. Furthermore, introduction of both the CF 3 and OTf groups of the trifluoromethanesulfonic anhydride into internal alkynes to access tetrasubstituted trifluoromethylated alkenes was achieved. Since trifluoromethanesulfonic anhydride is a low-cost and abundant chemical, this method provides a cost-efficient and practical route to trifluoromethylated compounds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of Substituted α-Trifluoromethyl Piperidinic Derivatives

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Sarah Rioton

2017-03-01

Full Text Available A comprehensive survey of pathways leading to the generation of α-trifluoromethyl monocyclic piperidinic derivatives is provided (65 references. These compounds have been synthesized either from 6-membered rings e.g., pipecolic acid or lactam derivatives by introduction a trifluoromethyl group, from pyridine or pyridinone derivatives by reduction, and from 5-membered rings e.g., prolinol derivatives by ring expansion, from linear amines by cyclization or from dienes/dienophiles by [4 + 2]-cycloaddition.

GC-MS analysis of polybrominated diphenyl ethers in Lake Erie

Science.gov (United States)

Vagula, Mary C.; Vartak, Marissa; Tallmadge, Weslene

2012-06-01

Lake Erie is one of the five great lakes of North America. It is the shallowest, the warmest, and the most biologically productive of the Great Lakes producing more fish than all of the other four lakes combined. It is also a source of drinking water for 11 million people and a recreational asset. On the flipside, it is also very vulnerable and troubled with environmental challenges because it has the smallest water volume, but the greatest pressures from the human settlement. One of the many issues faced by the Lake is pollution. It receives larger loads of many pollutants than any other Great Lake. Even with the best pollution controls many pesticides and organohalogens continue to enter the lake. Polybrominated diphenyl ethers (PBDEs) are a class of flame-retardants that have been used in a variety of consumer products since the 1970s. They are added to many commercial and household products such as computers, foam mattresses, carpets, etc. Being largely non-polar and chemically stable, these chemicals are extremely lipophilic and resist degradation in the environment, thus giving them a high affinity for their bioaccumulation. Due to these properties PBDEs have become ubiquitous environmental contaminants. These compounds are reported to be endocrine disruptors and could cause oxidative damage. This report presents the sample preparation protocol, the GC-MS analysis of PBDEs in Lake Erie sediment samples.

UV-A photooxidation of β-carotene in Triton X-100 micelles by nitrodiphenyl ether herbicides

International Nuclear Information System (INIS)

Orr, G.L.; Hogan, M.E.

1985-01-01

Photooxidation of β-carotene in Triton X-100 micelles was stimulated by lipophilic nitrodiphenyl ether herbicides at concentrations as low as 5 μM after 15 min in UV radiation (UV-A between 315 and 400 nm). Bleaching of β-carotene by acifluorfen-methyl [methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate] was proportional to UV-A intensity and independent of pH. White light (400-700 nm) alone was without effect. At pH 6.5, 100 μM acifluorfen [sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate], a water-soluble nitrodiphenyl ether, stimulated photooxidation of β-carotene after 15 min in UV-A radiation. Activity of 200 μM acifluorfen was enhanced at pHs between 3.5 and 6.5. The chlorodiphenyl ether analogue of acifluorfen-methyl, methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate, exhibited little activity at 200 μM and 200 μM phenyl ether was without effect. Activation energy for acifluorfen-methyl stimulated β-carotene photooxidation near 20 and 30 0 C was 40.3 and 5.6 kJ mol -1 , respectively. Subsequent to UV-A exposure and placement into darkness no further bleaching of β-carotene was detected, indicating that reactive species were generated only in light and consumed quickly in darkness

BDE99 (2,2′,4,4′,5-PENTABROMODIPHENYL ETHER) SUPPRESSES DIFFERENTIATION INTO NEUROTRANSMITTER PHENOTYPES IN PC12 CELLS

OpenAIRE

Slotkin, Theodore A.; Card, Jennifer; Infante, Alice; Seidler, Frederic J.

2013-01-01

Early-life exposures to brominated diphenyl ethers (BDEs) lead to neurobehavioral abnormalities later in life. Although these agents are thyroid disruptors, it is not clear whether this mechanism alone accounts for the adverse effects. We evaluated the impact of 2,2′,4,4′,5-pentabromodiphenyl ether (BDE99) on PC12 cells undergoing neurodifferentiation, contrasting the effects with chlorpyrifos, a known developmental neurotoxicant. BDE99 elicited decrements in the number of cells, evidenced by...

Influences of binding to dissolved organic matter on hydrophobic organic compounds in a multi-contaminant system: Coefficients, mechanisms and ecological risks.

Science.gov (United States)

Li, Yi-Long; He, Wei; Liu, Wen-Xiu; Kong, Xiang-Zhen; Yang, Bin; Yang, Chen; Xu, Fu-Liu

2015-11-01

The complexation flocculation (CF) method was successfully employed to identify binding coefficients (Kdoc) of specific organic contaminants to dissolved organic matter (DOM, often indicated by dissolved organic carbon, DOC) in a multi-contaminant hydrophobic organic contaminant (HOC) system. Kdoc values were obtained for most of the evaluated 33 HOCs, indicating the feasibility and applicability of the CF method in a multi-contaminant system. Significant positive correlations were observed between binding coefficients and octanol-water partition coefficients (Kow) for organic halogen compounds, such as polybrominated diphenyl ethers (PBDEs) (R(2) = 0.95, p mechanisms between PAHs and organic halogen compounds exist. These differences further result in discriminative competition partitions of HOCs between DOM and organisms. Assuming that only freely dissolved HOCs are bioconcentrative, the results of DOM-influenced bioconcentration factor (BCFDOM) and DOM-influenced lowest observed effect level (LOELDOM) indicate that the ecological risk of HOCs is decreased by DOM. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioaccumulation of polybrominated diphenyl ethers (PBDEs) in sediment aged for 2 years to carps (Cyprinus carpio)

Science.gov (United States)

Tian, S. Y.; Li, J. Y.; Jia, X. M.

2017-08-01

In order to understand the risk of polybrominated diphenyl ethers (PBDEs) existing in sediment for years, the accumulation of PBDEs in sediment aged for 2 years to fish was investigated. Simulated aquatic system microcosms were conducted with PBDE contaminated sediment aged for 2 years and carps were cultured in the microcosms for 20 days. PBDE concentrations in carp tissues were analyzed to estimate the bioavailability of aged PBDEs in carps. The main spiked PBDE congeners were detected in sediment even though the contaminated sediment was aged for 2 years. Similarly, the five PBDE (BDE-28, 47, 100, 153 and 154) congeners which probably were bioaccumulated by carp were detected in fish tissues, indicating that PBDEs could be bioaccumulated after aging for 2 years. The PBDEs distribution revealed that the concentrations of polybrominated diphenyl ethers in tissues of Cyprinus carpio is in this order of magnitude: gut > liver > gill > fillet. The PBDEs concentrations in fillet were as high as 67.9 ng/g dry wt, in which BDE-47 contributed almost 50% in profile.

Levels and distribution of polybrominated diphenyl ethers in various tissues of birds of prey

International Nuclear Information System (INIS)

Voorspoels, Stefan; Covaci, Adrian; Lepom, Peter; Jaspers, Veerle L.B.; Schepens, Paul

2006-01-01

In the present study, concentrations and tissue distribution of polybrominated diphenyl ethers (PBDEs; IUPAC nos. 28, 47, 99, 100, 153, 154, 183, and 209) were examined in brain, adipose tissue, liver, muscle, and serum of birds of prey. Median ΣPBDE levels (BDE 28-183) in the tissues of sparrowhawks ranged from 360 to 1900 ng/g lipid weight (lw), which was in general one order of magnitude higher than in the tissues of common buzzards (26-130 ng/g lw). There were no differences in PBDE congener patterns between the various tissues within individuals of a certain species. Inter-species differences in PBDE patterns and in particular the percentage of BDE 99, 100 and 153 were, however, pronounced between sparrowhawk and common buzzard. BDE 209 was detected in nearly all serum and in some liver samples, but not in any other tissues. This observation suggests that exposure to BDE 209 is low or that this congener is poorly accumulated. Passive (lipid content related) diffusion could not completely describe the PBDE tissue distribution, e.g. the lowest PBDE-load was measured in brain, a fairly lipid rich tissue. - Distribution of polybrominated diphenyl ethers in birds of prey is tissue dependent

Dietary accumulation and metabolism of polybrominated diphenyl ethers by juvenile carp (Cyprinus carpio).

Science.gov (United States)

Stapleton, Heather M; Letcher, Robert J; Li, Juliana; Baker, Joel E

2004-08-01

Polybrominated diphenyl ethers (PBDEs) are hydrophobic organic contaminants with properties and nomenclature similar to polychlorinated biphenyls (PCBs). While much information is available on the bioaccumulation and pharamcokinetics of PCBs, little information is available on PBDEs. In this study, juvenile carp were exposed to a diet spiked with a cocktail of four BDE congeners (2,4,4'-tribromoDE [BDE 28], 2,2',4,4'-tetrabromoDE [BDE 47], 2,2',4,4',5-pentabromoDE [BDE 99], and 2,2',4,4',5,5'hexabromoDE [BDE 153]) for 60 d followed by a 40-d depuration period. As a positive control, three PCB congeners with similar log K(ow), values (2,2',5,5'-tetrachlorobiphenyl [PCB 52], 2,2',4,4', 5,5'-hexachlorobiphenyl [PCB 153], and 2,2',3,4,4',5,5'-heptachlorobiphenyl [PCB 180]) were included in the cocktail to compare their assimilation and fate with the model BDE congeners. Concentrations of BDEs and PCBs were monitored in whole-fish tissues and liver tissues over the duration of the experiment. In addition, blood serum samples were taken and pooled among replicates to determine if any phenolic metabolites of BDE and PCBs were formed. Rapid assimilation of BDE 47 was observed relative to all other BDE and PCB congeners, whereas apparently no accumulation of BDE 99 occurred over the course of the experiment. Assimilation efficiencies for BDE 47 suggest that approximately 100% of the BDE 47 exposure was absorbed by carp tissues after 60 d. However, based on the time course of BDE 47 assimilation, it is improbable that all BDE 47 was assimilated; more likely, production of BDE 47 in carp tissues occurred as a result of debromination of higher-brominated compounds, possibly BDE 99. The net assimilation efficiencies of BDE 28 and BDE 153 were also apparently low (20 and 4%, respectively) relative to the three PCBs (40% assimilated) examined in this study. The low assimilation efficiency and high depuration rates for BDEs suggest a higher potential for biotransformation. While

Fate of polybrominated diphenyl ethers in the environment of the Pearl River Estuary, South China

International Nuclear Information System (INIS)

Guan Yufeng; Sojinu, O.S. Samuel; Li Shaomeng; Zeng, Eddy Y.

2009-01-01

Ninety-six riverine runoff samples collected at eight major outlets in the Pearl River Delta (PRD), South China, during 2005-2006 were analyzed for 17 brominated diphenyl ether (BDE) congeners (defined as Σ 17 PBDE). Fourteen and 15 congeners were detected, respectively, in the dissolved and particulate phases. These data were further used to elucidate the partitioning behavior of BDE congeners in riverine runoff. Several related fate processes, i.e. air-water exchange, dry and wet deposition, degradation, and sedimentation, within the Pearl River Estuary (PRE), were examined to estimate the inputs of Σ 10 PBDE (sum of the target BDE congeners, BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) and BDE-209 from the PRD to the coastal ocean based on mass balance considerations. The results showed that annual outflows of Σ 10 PBDE and BDE-209 were estimated at 126 and 940 kg/year, respectively from the PRE to coastal ocean. Besides sedimentation and degradation, the majority of Σ 10 PBDE and BDE-209 discharged into the PRE via riverine runoff was transported to the coastal ocean. - Fate of polybrominated diphenyl ethers in the environment the Pearl River Estuary, South China.

Fast Removal of Polybrominated Diphenyl Ethers from Aqueous Solutions by Using Low-Cost Adsorbents

Directory of Open Access Journals (Sweden)

Renin Chang

2017-01-01

Full Text Available 4-Dibromodiphenyl ether (BDE-3 and 4,4′-dibromodiphenyl ether (BDE-15 are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam–washed black tea, green tea, and coconut palm leaf powders were 21.85 mg·L−1, 14.56 mg·L−1 and 22.47 mg·L−1, respectively. The results also showed that the adsorption equilibrium (qe was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k2 of all pressure steam–washed adsorbents ranged from 8.16 × 10−3 to 6.61 × 10−2 g·(mg·L−1−1·s−1, and the amount adsorbed at qe by all pressure steam–washed adsorbents ranged from 4.21 to 4.78 mg·L−1. Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg·L−1, respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.

Metabolism of nitrodiphenyl ether herbicides by dioxin-degrading bacterium Sphingomonas wittichii RW1.

Science.gov (United States)

Keum, Young Soo; Lee, Young Ju; Kim, Jeong-Han

2008-10-08

Nitrodiphenyl ether herbicides, including chlomethoxyfen, nitrofen, and oxyfluorfen are potent herbicides. Some metabolites and parent compounds are considered as possible mutagens and endocrine disruptors. Both properties pose serious hygienic and environmental risks. Sphingomonas wittichii RW1 is a well-known degrader of polychlorinated dibenzo- p-dioxins, dibenzofurans, and diphenyl ethers. However, no detailed research of its metabolic activity has been performed against pesticides with a diphenyl ether scaffold. In this study, we report S. wittichii RW1 as a very potent diphenyl ether herbicide-metabolizing bacterium with broad substrate specificity. The structures of metabolites were determined by instrumental analysis and synthetic standards. Most pesticides were rapidly removed from the culture medium in the order of nitrofen > oxyfluorfen > chlomethoxyfen. In general, herbicides were degraded through the initial reduction and N-acetylation of nitro groups, followed by ether bond cleavage. Relatively low concentrations of phenolic and catecholic metabolites throughout the study suggested that these metabolites were rapidly metabolized and incorporated into primary metabolism. These results indicate that strain RW1 has very versatile metabolic activities over a wide range of environmental contaminants.

Identification of a novel dimethoxylated polybrominated biphenyl bioaccumulating in marine mammals

Energy Technology Data Exchange (ETDEWEB)

Marsh, G.; Athanasiadou, M.; Bergman, Aa.; Athanassiadis, I. [Department of Environmental Chemistry, Stockholm (Sweden); Endo, Tetsuya [Health Sciences Univ. of Hokkaido (Japan). Fac. of Pharmaceutical Sciences; Haraguchi, Koichi [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

2004-09-15

The screening of persistent halogenated organic pollutants has in recent years ended up with findings of numerous compounds being natural products. These compounds have preferably been reported from the marine environment and comprise, several hydroxylated and methoxylated polybrominated diphenyl ethers (OH-PBDEs and MeO-PBDEs) including monochlorinated ditto, a dimethoxylated polybrominated diphenyl ether i.e. 2',6-dimethoxy-2,3',4,5'-tetrabromodiphenyl ether, four halogenated dimethylated bipyrroles (HDBPs) with a 2,2'-bipyrrole backbone, a heptachlorinated 1,2'-bipyrrole i.e. heptachloro-1'-methyl-1,2'-bipyrrole (Q1)6 and a halogenated monoterpene holding two bromine and three chlorine atoms. We have taken interest in an organobrominated compound with an unknown structure but with a molecule ion of m/z = 526 and a four bromine isotope pattern according to mass spectrometry (MS), detected in marine mammal samples of which the majority were collected from Japanese coastal waters. This compound has recently been reported from several marine mammals collected on the Southern hemisphere, but neither the chemical structure nor the type of substance group were established. We here report the structure of this organobrominated compound, a dimethoxylated polybrominated biphenyl, which likely is of natural origin. The identification was done by the comparison of relative retention time (RRT) on two GC columns with different polarities and by comparing mass spectra from three different ionization techniques i.e. PICI, ECNI and EI, of the unknown compound from the samples with an authentic reference compound. Levels of the novel dimethoxylated polybrominated biphenyl are reported as well as the levels (for comparison) of some other known polybrominated compounds, both brominated flame retardants (BFRs) and natural products i.e. BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, 1,2,5,6,9,10- hexabromocyclododecane (HBCDD), 6-MeO-BDE-47, 2

Improving Infant Exposure and Health Risk Estimates: Using Serum Data to Predict Polybrominated Diphenyl Ether Concentrations in Breast Milk

Science.gov (United States)

Women in the United States have breast milk concentrations of polybrominated diphenyl ethers (PBDEs) that are among the highest in the world, leading to concerns over the potential health implications to breastfeeding infants during critical stages of growth and development. Deve...

Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

Energy Technology Data Exchange (ETDEWEB)

Malik, Riffat Naseem, E-mail: r_n_malik2000@yahoo.co.uk [Environmental Biology Laboratory, Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320 (Pakistan); Moeckel, Claudia [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Jones, Kevin C.; Hughes, David [Centre for Chemicals Management, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom)

2011-10-15

Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of {Sigma}PBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher {Sigma}hexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured {Sigma}PBDEs pose no risk to egret population. - Highlights: > Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. > PBDE-47 and -100 frequent in feathers of fish eating egrets. > BDE-99 dominant in feathers of egrets feed in terrestrial habitats. > Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. > Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

International Nuclear Information System (INIS)

Malik, Riffat Naseem; Moeckel, Claudia; Jones, Kevin C.; Hughes, David

2011-01-01

Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of ΣPBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher Σhexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured ΣPBDEs pose no risk to egret population. - Highlights: → Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. → PBDE-47 and -100 frequent in feathers of fish eating egrets. → BDE-99 dominant in feathers of egrets feed in terrestrial habitats. → Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. → Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

Concentration of polybrominated diphenyl ethers (PBDEs) in sediment cores of Sundarban mangrove wetland, northeastern part of Bay of Bengal (India)

Energy Technology Data Exchange (ETDEWEB)

Binelli, Andrea [Department of Biology, University of Milan, Via Celoria 26, 20133 Milan (Italy)]. E-mail: andrea.binelli@unimi.it; Sarkar, Santosh Kumar [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Chatterjee, Mousumi [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Riva, Consuelo [Department of Biology, University of Milan, Via Celoria 26, 20133 Milan (Italy); Parolini, Marco [Department of Biology, University of Milan, Via Celoria 26, 20133 Milan (Italy); Bhattacharya, Bhaskar deb [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Bhattacharya, Asok Kumar [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Satpathy, Kamala Kanta [Indira Gandhi Center for Atomic Research, Environmental and Industrial Safety Section, Safety Group, Kalpakkam 603 102, Tamil Nadu (India)

2007-08-15

The paper presents the first comprehensive survey of congener profiles (12 congeners) of polybrominated diphenyl ethers (PBDEs) in core sediment samples (<63 {mu}m) covering seven sites in Sundarban mangrove wetland (India). Gas-chromatographic analyses were carried out in GC-Ms/Ms for tri- to hepta- brominated congeners. Results pointed out a non-homogenous contamination of the wetland with {sigma}{sub 12} PBDE values ranging from 0.08 to 29.03 ng g{sup -1}, reflecting moderate to low contamination closely in conformity to other Asian aquatic environments. The general order of decreasing congener contribution to the total load was: BDE 47 > 99 > 100 > 154, similar to the distribution pattern worldwide. Although tetrabromodiphenyl ether BDE 47 was found in all samples followed by hexabromodiphenyl ether BDE-154, they were not necessarily the dominant congeners. No uniform temporal trend on PBDE levels was recorded probably due to particular hydrological characteristics of the wetland and/on non-homologous inputs from point sources (untreated municipal wastewater and local industries, electronic wastes from the dump sites, etc.) of these compounds. Because of the propensity of PBDEs to accumulate in various compartments of wildlife and human food webs, evaluation of biological tissues should be undertaken as a high priority.

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

Energy Technology Data Exchange (ETDEWEB)

John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

2002-06-01

Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

Polybrominated diphenyl ethers in influents, suspended particulate matter, sediments, sewage treatment plant and effluents and biota from the Netherlands

NARCIS (Netherlands)

Boer, de J.; Wester, P.G.; Horst, van der A.; Leonards, P.E.G.

2003-01-01

Polybrominated diphenyl ethers (PBDEs) have been determined in 133 samples of suspended particulate matter (SPM), sediments, sewage treatment plant (STP) influents and effluents, fish and mussels from various locations in The Netherlands, as a part of a large Dutch national study on estrogenic

Primary investigation on contamination pattern of legacy and emerging halogenated organic pollutions in freshwater fish from Liaohe River, Northeast China

International Nuclear Information System (INIS)

Ren Guofa; Wang Zhao; Yu Zhiqiang; Wang Yang; Ma Shengtao; Wu Minghong; Sheng Guoying; Fu Jiamo

2013-01-01

Legacy halogenated compounds, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and emerging organo-halogen pollutants such as Dechlorane Plus (DP), were detected in fish from an old industrial region in Northeast China. PCBs and PBDEs were detected in all of the samples, with concentrations ranging from 38.15 to 170.51 ng/g lipid weight, and 9.40–39.69 ng/g lipid weight, respectively. DP was detected in more than 90% of the samples with concentrations ranging from not detected (ND) to 470 pg g/g lipid weight. Compared with similar data in other areas of the world, PCBs, PBDEs and DP in fish from Liaohe River were at medium or low level. An unusually high percentage of PCB-209 was first reported in the fish samples collected from China. Other halogenated pollutions, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, octachlorostyrene, chlorinated anisole, chlorinated thioanisole, triclosan-methyl, and other pesticides, have also been identified in the fish samples. - Highlights: ► DP was reported in fish samples from river close to an old industrial base in China. ► The first report on the unusually high fraction of PCB-209 in samples from China. ► GC × GC–TOFMS was used to identify non-targeted halogenated pollutants. - An unusually high percentage of PCB-209 was first reported in the fish samples collected from China, which might indicate that there were distinct sources of pure PCB-209 in the region of Liaohe River.

Sleep-inducing N-alkyl-5-[m-(trifluoromethyl)phenyl]-5-hydroxy-2-pyrrolidinones and N-alkyl-3-(trifluoromethyl)cinnamamides.

Science.gov (United States)

Houlihan, W J; Gogerty, J H; Ryan, E A; Schmitt, G

1985-01-01

A series of N-alkyl-3-[m-(trifluoromethyl)phenyl]-5-hydroxy-2-pyrrolidinones and N-alkyl-3-(trifluoromethyl)-cinnamamides were prepared and screened in a series of tests designed to detect potential sleep inducers. The more active members of the series were evaluated for their ability to induce sleep in Cebus monkeys. The most active compound, N-methyl-5-[m-(trifluoromethyl)phenyl]-5-hydroxy-2-pyrrolidinone, was equal to methaqualone.

Photolytic debromination pathway of polybrominated diphenyl ethers in hexane by sunlight

International Nuclear Information System (INIS)

Wei, Hua; Zou, Yonghong; Li, An; Christensen, Erik R.; Rockne, Karl J.

2013-01-01

The objective of this work is to identify the photolytic debromination pathways of polybrominated diphenyl ethers (PBDEs). Thirteen PBDEs (BDEs 209, 208, 207, 206, 196, 183, 154, 153, 100, 99, 85, 47 and 28) in hexane were individually exposed to sunlight for up to 64 h. A total of 180 PBDEs were screened and 74 BDE debromination products were detected. The disappearance rate constant increased exponentially with increasing number of bromines. While no evident difference in debromination preference among ortho, meta and para bromines was found for heavier congeners, the vulnerability rank order was meta ≥ ortho > para for the lighter congeners (≤8 Br). The total molar mass of PBDEs continuously decreased during sunlight exposure, indicating PBDEs were transformed to non-PBDE compounds. A stochastic least squares debromination pathway model was developed to simulate the reactions and determine the yields to extend the results beyond the experimental observations. -- Highlights: ► 74 PBDEs are identified as the products of debromination via photolysis. ► Debromination is more likely at meta than para positions for PBDEs with ≤8 bromines. ► The stochastic least squares model results agree with and expand the experimental observations. ► Mass imbalance indicates a significant loss of PBDE mass during sunlight exposure. -- The PBDE debromination products and pathways identified in this work will assist in future studies on their environmental fate

Polybrominated diphenyl ethers (PBDEs) in leachates from selected landfill sites in South Africa.

Science.gov (United States)

Odusanya, David O; Okonkwo, Jonathan O; Botha, Ben

2009-01-01

The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenyl ethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE -28, -47, -66, -71, -75, -77, -85, -99, -100, -119, -138, -153, -154, and -183 have been detected in various environmental matrices. Generally, in South Africa, once the products containing these chemicals have outlived their usefulness, they are discarded into landfill sites. Consequently, the levels of PBDEs in leachates from landfill sites may give an indication of the general exposure and use of these compounds. The present study was aimed at determining the occurrence and concentrations of most common PBDEs in leachates from selected landfill sites. The extraction capacities of the solvents were also tested. Spiked landfill leachate samples were used for the recovery tests. Separation and determination of the PBDE congeners were carried out with a gas chromatograph equipped with Ni63 electron capture detector. The mean percentage recoveries ranged from 63% to 108% (n=3) for landfill leachate samples with petroleum ether giving the highest percentage extraction. The mean concentrations of PBDEs obtained ranged from ND to 2670pgl(-1), ND to 6638pgl(-1), ND to 7230pgl(-1), 41 to 4009pgl(-1), 90 to 9793pgl(-1) for the Garankuwa, Hatherly, Kwaggarsrand, Soshanguve and Temba landfill sites, respectively. Also BDE -28, -47, -71 and BDE-77 were detected in the leachate samples from all the landfill sites; and all the congeners were detected in two of the oldest landfill sites. The peak concentrations were recorded for BDE-47 at three sites and BDE-71 and BDE-75 at two sites. The highest concentration, 9793+/-1.5pgl(-1), was obtained for the Temba landfill site with the highest BOD value. This may suggest some influence of organics on the level of PBDEs. Considering the leaching characteristics of brominated flame retardants, there is a high possibility that with time these compounds may

Discussion of "Polybrominated diphenyl ethers in aircraft cabins--a source of human exposure?" by Anna Christiansson et al. [Chemosphere 73(10) (2008) 1654-1660].

Science.gov (United States)

Schecter, Arnold; Colacino, Justin; Haffner, Darrah; Patel, Keyur; Opel, Matthias; Päpke, Olaf

2010-01-01

This paper presents new data on the levels of polybrominated diphenyl ethers (PBDEs) in American airline workers. This pilot study did not find elevated total PBDEs in the blood of nine flight attendants and one aircraft pilot who have worked in airplanes for at least the past 5 years. These findings are not consistent with the findings of elevated blood levels of PBDEs from the 2008 Christiansson et al. publication "Polybrominated diphenyl ethers in aircraft cabins - A source of human exposure?" We agree that more research needs to be done on larger, more representative samples of airline workers to better characterize exposure of airline workers and other frequent flyers to PBDEs.

Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, naphthalenes and polybrominated diphenyl ethers in the edible fish caught from the Baltic Sea and lakes in Finland

International Nuclear Information System (INIS)

Isosaari, Pirjo; Hallikainen, Anja; Kiviranta, Hannu; Vuorinen, Pekka J.; Parmanne, Raimo; Koistinen, Jaana; Vartiainen, Terttu

2006-01-01

A total of 156 fish composite samples were collected from five areas of the Baltic Sea and from three lakes and analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polybrominated diphenyl ethers (PBDEs). The European Union's maximum permissible level for PCDD/Fs, 4 pg WHO-TEQ/g fresh weight (fw), was exceeded in salmon, river lamprey and Baltic herring. In other species from the Baltic Sea, the 90th percentile was 3.42 pg WHO PCDD/F -TEQ/g fw. In the lake fish, the concentrations of PCDD/Fs, PCBs and PCNs were only 29-46% of those in the same species caught from the Baltic Sea, whereas the concentrations of PBDEs in the lake fish were as high as in the Baltic Sea fish. Dioxin-like PCBs contributed to the total dioxin-like toxicity of PCBs and PCDD/Fs by 49 ± 12% in all the analysed samples. - Lake fish is less contaminated with dioxins, PCBs and chloronaphthalenes than Baltic Sea fish but similarly contaminated with polybrominated diphenyl ethers

Polybrominated diphenyl ethers: occurrence, dietary exposure, and toxicology.

Science.gov (United States)

Darnerud, P O; Eriksen, G S; Jóhannesson, T; Larsen, P B; Viluksela, M

2001-03-01

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in plastics (concentration, 5--30%) and in textile coatings. Commercial products consist predominantly of penta-, octa-, and decabromodiphenyl ether mixtures, and global PBDE production is about 40,000 tons per year. PBDEs are bioaccumulated and biomagnified in the environment, and comparatively high levels are often found in aquatic biotopes from different parts of the world. During the mid-1970--1980s there was a substantial increase in the PBDE levels with time in both sediments and aquatic biota, whereas the latest Swedish data (pike and guillemot egg) may indicate that levels are at steady state or are decreasing. However, exponentially increasing PBDE levels have been observed in mother's milk during 1972--1997. Based on levels in food from 1999, the dietary intake of PBDE in Sweden has been estimated to be 0.05 microg per day. Characteristic end points of animal toxicity are hepatotoxicity, embryotoxicity, and thyroid effects as well as maternal toxicity during gestation. Recently, behavioral effects have been observed in mice on administration of PBDEs during a critical period after birth. Based on the critical effects reported in available studies, we consider the lowest-observed-adverse-effect level (LOAEL) value of the PBDE group to be 1 mg/kg/day (primarily based on effects of pentaBDEs). In conclusion, with the scientific knowledge of today and based on Nordic intake data, the possible consumer health risk from PBDEs appears limited, as a factor of over 10(6) separates the estimated present mean dietary intake from the suggested LOAEL value. However, the presence of many and important data gaps, including those in carcinogenicity, reproduction, and developmental toxicity, as well as additional routes of exposure, make this conclusion only preliminary. Moreover, the time trend of PBDEs in human breast milk is alarming for the future.

Polybrominated diphenyl ethers--plasma levels and thyroid status of workers at an electronic recycling facility.

Science.gov (United States)

Julander, A; Karlsson, M; Hagström, K; Ohlson, C G; Engwall, M; Bryngelsson, I-L; Westberg, H; van Bavel, B

2005-08-01

Personnel working with electronic dismantling are exposed to polybrominated diphenyl ethers (PBDEs), which in animal studies have been shown to alter thyroid homeostasis. The aim of this longitudinal study was to measure plasma level of PBDEs in workers at an electronic recycling facility and to relate these to the workers' thyroid status. PBDEs and three thyroid hormones: triiodothyronine (T(3)), thyroxin (T(4)) and thyroid stimulating hormone (TSH) were repeatedly analysed in plasma from 11 workers during a period of 1.5 years. Plasma levels of PBDEs at start of employment were plasma levels of PBDEs fluctuated during the study period. Due to small changes in thyroid hormone levels it was concluded that no relevant changes were present in relation to PBDE exposure within the workers participating in this study.

Metals and polybrominated diphenyl ethers leaching from electronic waste in simulated landfills

Energy Technology Data Exchange (ETDEWEB)

Kiddee, Peeranart [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Naidu, Ravi, E-mail: ravi.naidu@crccare.com [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Wong, Ming H. [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong (China)

2013-05-15

Highlights: • Simulated landfill columns provided realistic results than lab based column study. • Column leachates showed significant seasonal effect on toxic substances. • Toxic substances in the landfill leachates pose environmental and health hazards. • A better management of e-waste is urgently needed. -- Abstract: Landfills established prior to the recognition of potential impacts from the leaching of heavy metals and toxic organic compounds often lack appropriate barriers and pose significant risks of contamination of groundwater. In this study, bioavailable metal(oids) and polybrominated diphenyl ethers (PBDEs) in leachates from landfill columns that contained intact or broken e-waste were studied under conditions that simulate landfills in terms of waste components and methods of disposal of e-wastes, and with realistic rainfall. Fourteen elements and PBDEs were analysed in leachates over a period of 21 months. The results demonstrate that the average concentrations of Al, Ba, Be, Cd, Co, Cr, Cu, Ni, Pb, Sb and V in leachates from the column that contained broken e-waste items were significantly higher than the column without e-waste. BDE-153 was the highest average PBDEs congener in all columns but the average of ∑PBDEs levels in columns that contained intact e-waste were (3.7 ng/l) and were not significantly higher than that in the leachates from the control column.

Effect of p-amino-diphenyl ethers on hepatic microsomal cytochrome P450.

Science.gov (United States)

Jiang, Huidi; Xuan, Guida

2003-09-01

The present paper aims to investigate whether p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450. Mice were given daily intraperitoneal (ip) injections of p-amino-2',4'-dichlorodiphenyl ether (0.25 mmol/kg) or p-amino-4'-methyldiphenyl ether (0.25 mmol/kg) for 4 days and tested at 24 h and 48 h after the last dose injection. The results showed the mice pentobarbital sleeping time was shorter and the P450 content of hepatic microsome increased significantly in the group pretreated with p-amino-4'-methyldiphenyl ether when compared with the control group, while in mice pretreated with p-amino-2',4'-dichlorodiphenyl ether the hepatic microsome P450 content increased but the pentobarbital sleeping time was extended in clear contrast to the control group. The sleeping time of the phenobarbital group (80 mg/kg daily ip injection for 4 days) was shortened at 24 h after the last injection with increased P450 content of hepatic microsome, but it showed no difference at 48 h. The zoxazolamine-paralysis times of mice treated with p-amino-2',4'-dichlorodiphenyl ether were longer than those of the control mice, while the same dose of zoxazolamine did not lead to paralysis in mice pretreated with BNF. p-Amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether inhibited the activity of 7-ethoxyresorufin O-deethylase from rat hepatic microsome induced by BNF in vitro by 70.0% and 50.1% respectively. These results suggest that p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450.

Primary investigation on contamination pattern of legacy and emerging halogenated organic pollutions in freshwater fish from Liaohe River, Northeast China

Energy Technology Data Exchange (ETDEWEB)

Ren Guofa, E-mail: rgf2008@shu.edu.cn [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Zhao, Wang [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Zhiqiang, Yu [State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Yang, Wang [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Shengtao, Ma [State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Minghong, Wu [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); Guoying, Sheng [State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Jiamo, Fu [Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, 99 Shangda Road, Baoshan Disrict, Shanghai 200072 (China); State Key Laboratory of Organic Geochemistry, Guangzhou Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2013-01-15

Legacy halogenated compounds, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and emerging organo-halogen pollutants such as Dechlorane Plus (DP), were detected in fish from an old industrial region in Northeast China. PCBs and PBDEs were detected in all of the samples, with concentrations ranging from 38.15 to 170.51 ng/g lipid weight, and 9.40-39.69 ng/g lipid weight, respectively. DP was detected in more than 90% of the samples with concentrations ranging from not detected (ND) to 470 pg g/g lipid weight. Compared with similar data in other areas of the world, PCBs, PBDEs and DP in fish from Liaohe River were at medium or low level. An unusually high percentage of PCB-209 was first reported in the fish samples collected from China. Other halogenated pollutions, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, octachlorostyrene, chlorinated anisole, chlorinated thioanisole, triclosan-methyl, and other pesticides, have also been identified in the fish samples. - Highlights: Black-Right-Pointing-Pointer DP was reported in fish samples from river close to an old industrial base in China. Black-Right-Pointing-Pointer The first report on the unusually high fraction of PCB-209 in samples from China. Black-Right-Pointing-Pointer GC Multiplication-Sign GC-TOFMS was used to identify non-targeted halogenated pollutants. - An unusually high percentage of PCB-209 was first reported in the fish samples collected from China, which might indicate that there were distinct sources of pure PCB-209 in the region of Liaohe River.

Occurrence, bioaccumulation and potential sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of South China

International Nuclear Information System (INIS)

Zhang Baozhong; Ni Honggang; Guan Yufeng; Zeng, Eddy Y.

2010-01-01

To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (±standard deviations) at 5.7 ± 3.6 ng/L in pond water, 15 ± 11 ng/g dry wt. in pond sediment, 12 ± 3.8 ng/g dry wt. in bank soil, 21 ± 20 ng/g lipid wt. in fish, and 93 ± 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish. - Occurrence and sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of the Pearl River Delta, South China are examined.

Polybrominated diphenyl ethers (PBDEs) in leachates from selected landfill sites in South Africa

International Nuclear Information System (INIS)

Odusanya, David O.; Okonkwo, Jonathan O.; Botha, Ben

2009-01-01

The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenyl ethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE -28, -47, -66, -71, -75, -77, -85, -99, -100, -119, -138, -153, -154, and -183 have been detected in various environmental matrices. Generally, in South Africa, once the products containing these chemicals have outlived their usefulness, they are discarded into landfill sites. Consequently, the levels of PBDEs in leachates from landfill sites may give an indication of the general exposure and use of these compounds. The present study was aimed at determining the occurrence and concentrations of most common PBDEs in leachates from selected landfill sites. The extraction capacities of the solvents were also tested. Spiked landfill leachate samples were used for the recovery tests. Separation and determination of the PBDE congeners were carried out with a gas chromatograph equipped with Ni 63 electron capture detector. The mean percentage recoveries ranged from 63% to 108% (n = 3) for landfill leachate samples with petroleum ether giving the highest percentage extraction. The mean concentrations of PBDEs obtained ranged from ND to 2670 pg l -1 , ND to 6638 pg l -1 , ND to 7230 pg l -1 , 41 to 4009 pg l -1 , 90 to 9793 pg l -1 for the Garankuwa, Hatherly, Kwaggarsrand, Soshanguve and Temba landfill sites, respectively. Also BDE -28, -47, -71 and BDE-77 were detected in the leachate samples from all the landfill sites; and all the congeners were detected in two of the oldest landfill sites. The peak concentrations were recorded for BDE-47 at three sites and BDE-71 and BDE-75 at two sites. The highest concentration, 9793 ± 1.5 pg l -1 , was obtained for the Temba landfill site with the highest BOD value. This may suggest some influence of organics on the level of PBDEs. Considering the leaching characteristics of brominated flame retardants, there is a high possibility that with time these

Polybrominated diphenyl ether exposure and reproductive hormones in North American men.

Science.gov (United States)

Makey, Colleen M; McClean, Michael D; Braverman, Lewis E; Pearce, Elizabeth N; Sjödin, Andreas; Weinberg, Janice; Webster, Thomas F

2016-07-01

Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals that are persistent organic pollutants. Animal experiments and some human studies indicate that PBDEs may adversely affect male reproductive function. To assess the association between PBDE exposure and reproductive hormones (RHs) in a North American male adult cohort. From 2010-11, we collected three serum samples from 27 healthy adult men. We assessed associations between PBDEs and RHs using mixed effect regression models. PBDEs were inversely associated with inhibin-B. In older men, increased concentrations of BDE-47 and BDE-100 were significantly associated with a decrease in inhibin-B, and an increase in follicular stimulating hormone (FSH). These findings suggest PBDE exposure may affect RHs in older men. We did not measure other parameters of male reproductive function and therefore these results are preliminary. Copyright © 2016 Elsevier Inc. All rights reserved.

Depositional characteristics of atmospheric polybrominated diphenyl ethers on tree barks.

Science.gov (United States)

Chun, Man Young

2014-07-17

This study was conducted to determine the depositional characteristics of several tree barks, including Ginkgo (Ginkgo biloba), Pine (Pinus densiflora), Platanus (Platanus), and Metasequoia (Metasequoia glyptostroboides). These were used as passive air sampler (PAS) of atmospheric polybrominated diphenyl ethers (PBDEs). Tree barks were sampled from the same site. PBDEs were analyzed by highresolution gas chromatography/high-resolution mass spectrometer, and the lipid content was measured using the gravimetric method by n-hexane extraction. Gingko contained the highest lipid content (7.82 mg/g dry), whereas pine (4.85 mg/g dry), Platanus (3.61 mg/g dry), and Metasequoia (0.97 mg/g dry) had relatively lower content. The highest total PBDEs concentration was observed in Metasequoia (83,159.0 pg/g dry), followed by Ginkgo (53,538.4 pg/g dry), Pine (20,266.4 pg/g dry), and Platanus (12,572.0 pg/g dry). There were poor correlations between lipid content and total PBDE concentrations in tree barks (R(2)=0.1011, p =0.682). Among the PBDE congeners, BDE 206, 207 and 209 were highly brominated PBDEs that are sorbed to particulates in ambient air, which accounted for 90.5% (84.3-95.6%) of the concentration and were therefore identified as the main PBDE congener. The concentrations of particulate PBDEs deposited on tree barks were dependent on morphological characteristics such as surface area or roughness of barks. Therefore, when using the tree barks as the PAS of the atmospheric PBDEs, samples belonging to same tree species should be collected to reduce errors and to obtain reliable data.

Exponential increases of the brominated flame retardants, polybrominated diphenyl ethers, in the Canadian Arctic from 1981 to 2000.

Science.gov (United States)

Ikonomou, Michael G; Rayne, Sierra; Addison, Richard F

2002-05-01

A suite of 37 polybrominated diphenyl ether (PBDE) congeners and all of the homologue groups from mono- to deca-brominated were determined in ringed seal (Phoca hispida) blubber collected from subsistence hunts in the Canadian Arctic in 1981, 1991, 1996, and 2000. Total PBDE (sum(PBDE)) concentrations have increased exponentially over this period in male ringed seals aged 0-15 years. Penta- and hexa-BDEs are increasing at approximately the same rate (t2 = 4.7 and 4.3 years, respectively) and more rapidly than tetra-BDEs (t2 = 8.6 years) and tri-BDEs (t2 = infinity) in this age/sex grouping. In contrast to declining PBDE concentrations since 1997 in human milk from Sweden, sum(PBDE) concentrations in arctic ringed seals continue to increase exponentially similar to worldwide commercial penta-BDE production. PBDE congener profiles in male ringed seals aged 0-15 years from 1991 to 2000 also differ significantly from other aquatic organisms and semipermeable membrane devices collected from temperate coastal regions of British Columbia. While PBDE concentrations are 50 times lower than those of mono-ortho and non-ortho PCBs, and approxiamately 500 times higher than PCDD/Fs, our data indicate that, at current rates of bioaccumulation, PBDEs will surpass PCBs to become the most prevalent organohalogen compound in Canadian arctic ringed seals by 2050.

Application of a congener-specific debromination model to study photodebromination, anaerobic microbial debromination, and FE0 reduction of polybrominated diphenyl ethers

NARCIS (Netherlands)

Zeng, X.; Simonich, S.L.M.; Robrock, K.R.; Korytar, P.; Alvarez-Cohen, L.; Barofsky, D.F.

2010-01-01

A model was used to predict the photodebromination of the BDE-203, 197, 196, and 153, the major components of the octa-polybrominated diphenyl ether (PBDE) technical mixture, as well as BDE-47, and the predicted results were compared to the experimental results. The predicted reaction time profiles

A potent trifluoromethyl ketone histone deacetylase inhibitor exhibits class-dependent mechanism of action

DEFF Research Database (Denmark)

Madsen, Andreas Stahl; Olsen, Christian Adam

2016-01-01

Histone deacetylase (HDAC) enzymes are validated targets for treatment of certain cancers and have potential as targets for pharmacological intervention in a number of other diseases. Thus, inhibitors of these enzymes have received considerable attention, but these are often evaluated by IC50 value......-on–fast-off mechanism was observed, but the trifluoromethyl ketone compound exhibited differential mechanisms depending on the enzyme isoform. The trifluoromethyl ketone compound displayed a fast-on–fast-off mechanism against class-IIa HDACs 4 and 7, but slow-binding mechanisms against class-I and class-IIb enzymes...

Neonatal exposure to polybrominated diphenyl ether (PBDE 153) disrupts spontaneous behaviour, impairs learning and memory, and decreases hippocampal cholinergic receptors in adult mice

International Nuclear Information System (INIS)

Viberg, Henrik; Fredriksson, Anders; Eriksson, Per

2003-01-01

Neonatal exposure to polybrominated diphenyl ether (PBDE 153) disrupts spontaneous behaviour, impairs learning and memory, and decreases hippocampal cholinergic receptors in adult mice. Flame retardants are used to suppress or inhibit combustion processes in an effort to reduce the risk of fire. One class of flame retardants, polybrominated diphenyl ethers (PBDEs), are present and increasing in the environment and in human milk. The present study shows that neonatal exposure to 2,2',4,4',5,5'-hexaBDE (PBDE 153), a PBDE persistent both in environment and in human milk, can induce developmental neurotoxic effects, such as changes in spontaneous behaviour (hyperactivity), impairments in learning and memory, and reduced amounts of nicotinic receptors, effects that get worse with age. Neonatal NMRI male mice were orally exposed on day 10 to 0.45, 0.9, or 9.0 mg of PBDE 153/kg of body weight. Spontaneous behaviour (locomotion, rearing, and total activity) was observed in 2-, 4-, and 6-month-old mice, Morris water maze at an age of 6 months. The behaviour tests showed that the effects were dose-response and time-response related. Animals showing defects in learning and memory also showed significantly reduced amounts of nicotinic receptors in hippocampus, using α-bungarotoxin binding assay. The observed developmental neurotoxic effects seen for PBDE 153 are similar to those seen for PBDE 99 and for certain PCBs. Furthermore, PBDEs appear to as potent as the PCBs

Identifying bioaccumulative halogenated organic compounds using a nontargeted analytical approach: seabirds as sentinels.

Directory of Open Access Journals (Sweden)

Christopher J Millow

Full Text Available Persistent organic pollutants (POPs are typically monitored via targeted mass spectrometry, which potentially identifies only a fraction of the contaminants actually present in environmental samples. With new anthropogenic compounds continuously introduced to the environment, novel and proactive approaches that provide a comprehensive alternative to targeted methods are needed in order to more completely characterize the diversity of known and unknown compounds likely to cause adverse effects. Nontargeted mass spectrometry attempts to extensively screen for compounds, providing a feasible approach for identifying contaminants that warrant future monitoring. We employed a nontargeted analytical method using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS to characterize halogenated organic compounds (HOCs in California Black skimmer (Rynchops niger eggs. Our study identified 111 HOCs; 84 of these compounds were regularly detected via targeted approaches, while 27 were classified as typically unmonitored or unknown. Typically unmonitored compounds of note in bird eggs included tris(4-chlorophenylmethane (TCPM, tris(4-chlorophenylmethanol (TCPMOH, triclosan, permethrin, heptachloro-1'-methyl-1,2'-bipyrrole (MBP, as well as four halogenated unknown compounds that could not be identified through database searching or the literature. The presence of these compounds in Black skimmer eggs suggests they are persistent, bioaccumulative, potentially biomagnifying, and maternally transferring. Our results highlight the utility and importance of employing nontargeted analytical tools to assess true contaminant burdens in organisms, as well as to demonstrate the value in using environmental sentinels to proactively identify novel contaminants.

Polybrominated diphenyl ethers in birds of prey from Northern China.

Science.gov (United States)

Chen, Da; Mai, Bixian; Song, Jie; Sun, Quanhui; Luo, Yong; Luo, Xiaojun; Zeng, Eddy Y; Hale, Robert C

2007-03-15

Birds of prey from Northern China (Beijing area) were examined for polybrominated diphenyl ethers (PBDEs). A total of 47 specimens from eight different species were analyzed. Muscle and liver were analyzed separately for each bird. Kidneys were pooled by species. Common kestrels exhibited the highest PBDE levels (mean muscle and liver concentrations of 12300 and 12200 ng/g lipid weight, respectively), with maxima in an individual bird of 31700 in muscle and 40900 ng/g lw in liver. Congener profiles differed between some species, but were generally dominated by the more brominated congeners (e.g., BDE-153, -209, -183, -207). BDE-209 was especially elevated compared to other published reports. Interspecies differences in congener concentrations and profiles may be due to diet, behavior, or biotransformation capacities. BDE-209 was detected in 79.4% of the samples. Common kestrels contained the highest BDE-209 levels (mean/maxima of 2150/6220 in muscle and 2870/12200 ng/g lw in liver). BDE-209 was the dominant congener in tissues from some buzzards, scops owls, and long-eared owls. It was the second most abundant congener in common kestrels. The remarkable levels and dominance of BDE-209 may relate to significant production, usage, or disposal of deca-containing products in China. These observations reinforce the growing view that organisms using terrestrial food chains may have greater exposure to BDE-209.

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

Energy Technology Data Exchange (ETDEWEB)

John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

2003-07-01

Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward

Current levels of primary polybrominated diphenyl ethers (PBDEs) in Norwegian seafood

Energy Technology Data Exchange (ETDEWEB)

Bethune, C.; Nielsen, J.; Julshamn, K. [National Institute of Nutrition and Seafood Research, Bergen (Norway)

2004-09-15

The brominated flame retardants (BFRs) represent major industrial chemicals whose use has increased dramatically over the past few decades. Polybrominated diphenyl ethers (PBDEs) are BFRs that are used in many types of consumer products. PBDEs have come to the attention of regulators and scientists due to their bioaccumulation, increasing exposure and persistence in the environment, and adverse health effects in animals and humans. Although PBDE contamination in marine fish was first detected in Sweden in 1979, and certain PBDEs are now banned as of this year, the European Union has yet to establish regulations on PBDE levels in either feed or seafood. The determination of these contaminants in consumer seafood is important for dietary exposure assessment and protection of human health. This study reports on the levels of 6 prominent PBDE congeners (28, 47, 99, 100, 153, and 154) in a selection of common Norwegian seafood.

Occurrence of organochlorine pesticides (OCPs) and their enantiomeric signatures, and concentrations of polybrominated diphenyl ethers (PBDEs) in the Adelie penguin food web, Antarctica

International Nuclear Information System (INIS)

Corsolini, Simonetta; Covaci, Adrian; Ademollo, Nicoletta; Focardi, Silvano; Schepens, Paul

2006-01-01

Concentrations and enantiomeric signatures of organochlorine pesticides were determined in Antarctic krill, emerald rockcod and Adelie penguin from the Ross Sea, Antarctica. HCB and DDTs were prevalent contaminants in penguin eggs. The highest concentrations of ΣHCHs (1.35 ± 0.72 ng/g) were found in the rockcod muscle, where γ-HCH (1.23 ± 0.67 ng/g) was the principal isomer. The ratio γ-HCH/α-HCH was evaluated. Enantioselective gas chromatography was used for the evaluation of enantiomeric fractions (EFs) for α-HCH and oxychlordane. An increase of 14% in the (+)α-HCH enantiomer was found from krill through penguin, suggesting the enantioselective biotrasformation increased proportionately with trophic level. Polybrominated diphenyl ethers (PBDEs) were measured and their concentrations were 5.6 ± 1.12, 5.81 ± 2.32, 4.57 ± 0.17 and 3.06 ± 3.27 ng/g lipids in krill, rockcod muscle, rockcod homogenate and penguin eggs, respectively. The detection of BDE28, BDE47, BDE99 and BDE100 in Antarctic organisms confirmed their global transport and distribution; the detection of lower brominated congeners suggested a potential long-range transport. - Enantiomeric signature and accumulation of polybrominated diphenyl ethers in the Adelie Penguin food chain are discussed

Research progress on trifluoromethyl-based radical reaction process

Science.gov (United States)

Song, Hao

2017-12-01

Due to the unique properties imparted by the trifluoromethyl group, such as high electron density and strong lipotropy, which effectively improve acidity, lipophilicity and metabolic stability of the molecule itself, trifluoromethyl-substituted organic compounds are becoming increasingly important as structural motifs in pharmaceuticals, agrochemicals and organic materials. In this review, we present several methods developed for the direct introduction of a trifluoromethyl group, beginning with its rich and storied history. Then the present article addresses mechanism and process in carbon-carbon bond forming reaction based on radical process which is divided into three parts according to the way of CF3 radical generation. Finally, challenges and opportunities of researches on trifluoromethylation reactions facing are prospected.

Chiral halogenated Schiff base compounds: green synthesis, anticancer activity and DNA-binding study

Science.gov (United States)

Ariyaeifar, Mahnaz; Amiri Rudbari, Hadi; Sahihi, Mehdi; Kazemi, Zahra; Kajani, Abolghasem Abbasi; Zali-Boeini, Hassan; Kordestani, Nazanin; Bruno, Giuseppe; Gharaghani, Sajjad

2018-06-01

Eight enantiomerically pure halogenated Schiff base compounds were synthesized by reaction of halogenated salicylaldehydes with 3-Amino-1,2-propanediol (R or S) in water as green solvent at ambient temperature. All compounds were characterized by elemental analyses, NMR (1H and 13C), circular dichroism (CD) and FT-IR spectroscopy. FS-DNA binding studies of these compounds carried out by fluorescence quenching and UV-vis spectroscopy. The obtained results revealed that the ligands bind to DNA as: (Rsbnd ClBr) > (Rsbnd Cl2) > (Rsbnd Br2) > (Rsbnd I2) and (Ssbnd ClBr) > (Ssbnd Cl2) > (Ssbnd Br2) > (Ssbnd I2), indicating the effect of halogen on binding constant. In addition, DNA-binding constant of the Ssbnd and R-enantiomers are different from each other. The ligands can form halogen bonds with DNA that were confirmed by molecular docking. This method was also measured the bond distances and bond angles. The study of obtained data can have concluded that binding affinity of the ligands to DNA depends on strength of halogen bonds. The potential anticancer activity of ligands were also evaluated on MCF-7 and HeLa cancer cell lines by using MTT assay. The results showed that the anticancer activity and FS-DNA interaction is significantly dependent on the stereoisomers of Schiff base compounds as R-enantiomers displayed significantly higher activity than S-enantiomers. The molecular docking was also used to illustrate the specific DNA-binding of synthesized compounds and groove binding mode of DNA interaction was proposed for them. In addition, molecular docking results indicated that there are three types of bonds (Hsbnd and X-bond and hX-bond) between synthesized compounds and base pairs of DNA.

Regioselective 1,4-trifluoromethylation of α,β-unsaturated ketones via a S-(trifluoromethyldiphenylsulfonium salts/copper system

Directory of Open Access Journals (Sweden)

Satoshi Okusu

2013-10-01

Full Text Available Regioselective conjugate 1,4-trifluoromethylation of α,β-unsaturated ketones by the use of shelf-stable electrophilic trifluoromethylating reagents, S-(trifluoromethyldiphenylsulfonium salts and copper under mild conditions is described. A wide range of acyclic aryl–aryl–enones and aryl–alkyl–enones were converted into β-trifluoromethylated ketones in low to moderate yields.

Depositional characteristics of atmospheric polybrominated diphenyl ethers on tree barks

Directory of Open Access Journals (Sweden)

Man Young Chun

2014-07-01

Full Text Available Objectives This study was conducted to determine the depositional characteristics of several tree barks, including Ginkgo (Ginkgo biloba, Pine (Pinus densiflora, Platanus (Platanus, and Metasequoia (Metasequoia glyptostroboides. These were used as passive air sampler (PAS of atmospheric polybrominated diphenyl ethers (PBDEs. Methods Tree barks were sampled from the same site. PBDEs were analyzed by highresolution gas chromatography/high-resolution mass spectrometer, and the lipid content was measured using the gravimetric method by n-hexane extraction. Results Gingko contained the highest lipid content (7.82 mg/g dry, whereas pine (4.85 mg/g dry, Platanus (3.61 mg/g dry, and Metasequoia (0.97 mg/g dry had relatively lower content. The highest total PBDEs concentration was observed in Metasequoia (83,159.0 pg/g dry, followed by Ginkgo (53,538.4 pg/g dry, Pine (20,266.4 pg/g dry, and Platanus (12,572.0 pg/g dry. There were poor correlations between lipid content and total PBDE concentrations in tree barks (R2=0.1011, p =0.682. Among the PBDE congeners, BDE 206, 207 and 209 were highly brominated PBDEs that are sorbed to particulates in ambient air, which accounted for 90.5% (84.3-95.6% of the concentration and were therefore identified as the main PBDE congener. The concentrations of particulate PBDEs deposited on tree barks were dependent on morphological characteristics such as surface area or roughness of barks. Conclusions Therefore, when using the tree barks as the PAS of the atmospheric PBDEs, samples belonging to same tree species should be collected to reduce errors and to obtain reliable data.

Involvement of reactive oxygen species in brominated diphenyl ether-47-induced inflammatory cytokine release from human extravillous trophoblasts in vitro

International Nuclear Information System (INIS)

Park, Hae-Ryung; Kamau, Patricia W.; Loch-Caruso, Rita

2014-01-01

Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant compounds. Brominated diphenyl ether (BDE)-47 is one of the most prevalent PBDE congeners found in human breast milk, serum and placenta. Despite the presence of PBDEs in human placenta, effects of PBDEs on placental cell function are poorly understood. The present study investigated BDE-47-induced reactive oxygen species (ROS) formation and its role in BDE-47-stimulated proinflammatory cytokine release in a first trimester human extravillous trophoblast cell line, HTR-8/SVneo. Exposure of HTR-8/SVneo cells for 4 h to 20 μM BDE-47 increased ROS generation 1.7 fold as measured by the dichlorofluorescein (DCF) assay. Likewise, superoxide anion production increased approximately 5 fold at 10 and 15 μM and 9 fold at 20 μM BDE-47 with a 1-h exposure, as measured by cytochrome c reduction. BDE-47 (10, 15 and 20 μM) decreased the mitochondrial membrane potential by 47–64.5% at 4, 8 and 24 h as assessed with the fluorescent probe Rh123. Treatment with 15 and 20 μM BDE-47 stimulated cellular release and mRNA expression of IL-6 and IL-8 after 12 and 24-h exposures: the greatest increases were a 35-fold increased mRNA expression at 12 h and a 12-fold increased protein concentration at 24 h for IL-6. Antioxidant treatments (deferoxamine mesylate, (±)α-tocopherol, or tempol) suppressed BDE-47-stimulated IL-6 release by 54.1%, 56.3% and 37.7%, respectively, implicating a role for ROS in the regulation of inflammatory pathways in HTR-8/SVneo cells. Solvent (DMSO) controls exhibited statistically significantly decreased responses compared with non-treated controls for IL-6 release and IL-8 mRNA expression, but these responses were not consistent across experiments and times. Nonetheless, it is possible that DMSO (used to dissolve BDE-47) may have attenuated the stimulatory actions of BDE-47 on cytokine responses. Because abnormal activation of proinflammatory responses can disrupt trophoblast functions

Involvement of reactive oxygen species in brominated diphenyl ether-47-induced inflammatory cytokine release from human extravillous trophoblasts in vitro

Energy Technology Data Exchange (ETDEWEB)

Park, Hae-Ryung, E-mail: heaven@umich.edu; Kamau, Patricia W.; Loch-Caruso, Rita

2014-01-15

Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant compounds. Brominated diphenyl ether (BDE)-47 is one of the most prevalent PBDE congeners found in human breast milk, serum and placenta. Despite the presence of PBDEs in human placenta, effects of PBDEs on placental cell function are poorly understood. The present study investigated BDE-47-induced reactive oxygen species (ROS) formation and its role in BDE-47-stimulated proinflammatory cytokine release in a first trimester human extravillous trophoblast cell line, HTR-8/SVneo. Exposure of HTR-8/SVneo cells for 4 h to 20 μM BDE-47 increased ROS generation 1.7 fold as measured by the dichlorofluorescein (DCF) assay. Likewise, superoxide anion production increased approximately 5 fold at 10 and 15 μM and 9 fold at 20 μM BDE-47 with a 1-h exposure, as measured by cytochrome c reduction. BDE-47 (10, 15 and 20 μM) decreased the mitochondrial membrane potential by 47–64.5% at 4, 8 and 24 h as assessed with the fluorescent probe Rh123. Treatment with 15 and 20 μM BDE-47 stimulated cellular release and mRNA expression of IL-6 and IL-8 after 12 and 24-h exposures: the greatest increases were a 35-fold increased mRNA expression at 12 h and a 12-fold increased protein concentration at 24 h for IL-6. Antioxidant treatments (deferoxamine mesylate, (±)α-tocopherol, or tempol) suppressed BDE-47-stimulated IL-6 release by 54.1%, 56.3% and 37.7%, respectively, implicating a role for ROS in the regulation of inflammatory pathways in HTR-8/SVneo cells. Solvent (DMSO) controls exhibited statistically significantly decreased responses compared with non-treated controls for IL-6 release and IL-8 mRNA expression, but these responses were not consistent across experiments and times. Nonetheless, it is possible that DMSO (used to dissolve BDE-47) may have attenuated the stimulatory actions of BDE-47 on cytokine responses. Because abnormal activation of proinflammatory responses can disrupt trophoblast functions

Effect of developmental low dose PBDE 47 exposure on thyroid hormone status and serum concentrations of FSH and inhibin B in male rats

Energy Technology Data Exchange (ETDEWEB)

Andrade, A.J.M.; Kuriyama, S.N.; Akkoc, Z.; Talsness, C.E.; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin

2004-09-15

Several persistent halogenated organic compounds such as PCBs, dioxins and more recently, polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone homeostasis in experimental animals. Particular concern exists regarding exposure to these compounds during critical periods of development when thyroid hormones orchestrate the growth and differentiation of many organs including the brain and the testis. While the contamination levels of PCBs and other persistent organic pollutants have declined in the past years, increasing levels of PBDEs have been detected in environmental and human samples including human breast milk. PBDEs are produced in large quantities and used worldwide as flame retardants in electrical appliances, carpets and furniture upholstery. Similar to other halogenated environmental organic pollutants, PBDEs seem to present a wide range of toxic effects including reproductive, endocrine, neurobehavioral and hepatic toxicity. Recently, it has been demonstrated that in utero and pubertal exposures to DE-71 (a commercial mixture containing mostly tetra- and penta-bromodiphenyl ethers) significantly reduce thyroxine levels (T4) in rats. The present study has focused on the possible effects of the tetra- BDE congener 2,2'4,4'-tetrabromo diphenyl ether (PBDE 47) on thyroid hormone status and associated changes on FSH and inhibin B levels in the developing male rat. We administered a single dose to gravid dams on gestation day 6 of either 140 {mu}g/kg BW or 700 {mu}g/kg BW PBDE 47. These doses are pertinent to human exposure situation because a study by She et al.3 found a mean level of 33.3 {mu}g PBDE 47 /kg fat in human breast adipose tissue with a range from 7.01 to 196 {mu}g PBDE 47 /kg fat.

Halogen bonding from a hard and soft acids and bases perspective: investigation by using density functional theory reactivity indices.

Science.gov (United States)

Pinter, Balazs; Nagels, Nick; Herrebout, Wouter A; De Proft, Frank

2013-01-07

Halogen bonds between the trifluoromethyl halides CF(3)Cl, CF(3)Br and CF(3)I, and dimethyl ether, dimethyl sulfide, trimethylamine and trimethyl phosphine were investigated using Pearson's hard and soft acids and bases (HSAB) concept with conceptual DFT reactivity indices, the Ziegler-Rauk-type energy-decomposition analysis, the natural orbital for chemical valence (NOCV) framework and the non-covalent interaction (NCI) index. It is found that the relative importance of electrostatic and orbital (charge transfer) interactions varies as a function of both the donor and acceptor molecules. Hard and soft interactions were distinguished and characterised by atomic charges, electrophilicity and local softness indices. Dual-descriptor plots indicate an orbital σ hole on the halogen similar to the electrostatic σ hole manifested in the molecular electrostatic potential. The predicted high halogen-bond-acceptor affinity of N-heterocyclic carbenes was evidenced in the highest complexation energy for the hitherto unknown CF(3) I·NHC complex. The dominant NOCV orbital represents an electron-density deformation according to a n→σ*-type interaction. The characteristic signal found in the reduced density gradient versus electron-density diagram corresponds to the non-covalent interaction between contact atoms in the NCI plots, which is the manifestation of halogen bonding within the NCI theory. The unexpected C-X bond strengthening observed in several cases was rationalised within the molecular orbital framework. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method of determining of polybrominated diphenyl ethers in fish and fish products by the method of liquid chromatography

Directory of Open Access Journals (Sweden)

O.N. Timofeeva

2016-09-01

Full Text Available The aim of the work was to develop a methodology for determining of polybrominated diphenyl ethers (PBDE in fish and fish products for the control of impurities content in the food and environmental objects in general. The conditions of chromatography (temperature conditions, the impact of the speed and magnitude of dividing of the gas-carrier stream using a HP-1 capillary columns, the DB-5, HP-50 +, DB-1; and lipids destructive and non-destructive cleaning methods of extract during the determination of PBDEs. The method of determination of 2,2,4,4-Tetrabromodiphenyl ether (BDE-47, 2,2,4,4,5-pentabromodiphenyl ether (BDE-99 and decabromodiphenyl ether (BDE-209 in fish and fish products by the liquid chromatography with electron detector was suggested. The method of PBDE is based on the extraction of samples with hexane-acetone (3:1, purification of the extract with concentrated sulfuric acid (phase ratio hexane-sulfuric acid – 5:1. The second purification step is carried out by using solid phase extraction cartridges «SiOH-H2SO4/SA» and hexane as the eluent. Gas chromatographic analysis of the determination of BDE-47 and BDE-99 is carried out on low-polar capillary column DB-5 (30 m x0.25 mm x0.25 mum with the programming of the column temperature. In determining the BDE-209 a DB-1 nonpolar capillary column was used (15 m x 0.25 mm x 0.1 mum with the column temperature programming. Calculation of the content of BDE-47 and BDE-99 is carried out with the internal standard (2,2, 3,4,4-pentabromodiphenyl ether (BDE-85, BDE-209 by absolute calibration. In determining the BDE-209 the calibration matrix was used. The range of concentrations of the calibration solutions for the determination of BDE-47 and BDE-99 is 0.005–0.05 g/cm 3 , for BDE-209 0.05–0.3 g/cm 3 . The technique allows the measurement of BDE-47 and BDE-99 in the range of 0.0002–0.05 mg/kg of the product concerned; BDE-209 – in the range of 0.002–0.3 mg/kg. The metrological

Dipropyl 3,6-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2-dicarboxylate.

Science.gov (United States)

Rao, Guo-Wu; Hu, Wei-Xiao

2003-05-01

The title compound, C(22)H(24)N(4)O(4), was prepared from propyl chloroformate and 3,6-diphenyl-1,2-dihydro-s-tetrazine. This reaction yields the title compound rather than dipropyl 3,6-diphenyl-1,4-dihydro-s-tetrazine-1,4-dicarboxylate. The 2,3-diazabutadiene group in the central six-membered ring is not planar; the C=N double-bond length is 1.285 (2) A, and the average N-N single-bond length is 1.401 (3) A, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie +/- 0.3268 (17) A from the plane of the ring. The molecule has twofold crystallographic symmetry.

Children's exposure to polybrominated diphenyl ethers (PBDEs) through mouthing toys.

Science.gov (United States)

Ionas, Alin C; Ulevicus, Jocelyn; Gómez, Ana Ballesteros; Brandsma, Sicco H; Leonards, Pim E G; van de Bor, Margot; Covaci, Adrian

2016-02-01

Polybrominated diphenyl ethers (PBDEs) have previously been detected in children toys, yet the risk of child exposure to these chemicals through the mouthing of toys or other items is still unknown. We aimed to expand on the current knowledge by investigating the impact of infants' mouthing activities on exposure to PBDEs present in toys. This was established by a leaching model for determining the amount PBDEs that can leach from toys into saliva in simulated conditions. The PBDE migration rate was at its highest for the 15 min low-exposure scenario incubations (198 pg/cm(2) × min) with the ERM EC-591 certified reference material (CRM) (0.17% w/w PBDEs). The leaching process was congener-dependent, since the percentage of lower brominated PBDE congeners that leached out was up to 4.5 times higher than for the heavier PBDEs. To study the scenario in which a child would mouth on a toy flame retarded with BDE 209 alone, a plastic item containing 7% BDE 209 (w/w) was also tested. The BDE 209 amounts leached out in only 15 min were higher than the amounts leached from the CRM after the 16 h incubation. For the Belgian population, the exposure scenario from mouthing on toys containing PBDEs in amounts similar to the REACH threshold was found to be lower than the exposure from mother's milk, but higher than the exposure through diet or even dust. Copyright © 2015 Elsevier Ltd. All rights reserved.

Particle size fractionation and human exposure of polybrominated diphenyl ethers in indoor dust from Chicago.

Science.gov (United States)

Wei, Hua; Turyk, Mary; Cali, Salvatore; Dorevitch, Samuel; Erdal, Serap; Li, An

2009-11-01

The objective of this study was to investigate the concentration level, the mass distribution based on dust particle size, and the associated human exposure of polybrominated diphenyl ethers (PBDEs) in indoor dust. The total concentration of 13 PBDEs Sigma(13)(BDEs) was found to be 500-6,944 ng/g in indoor dusts, 4,000 ng/g in car interior dust, 260-300 ng/g in outdoor ambient air particles, 30 ng/g in carpet fibers, and as high as 0.5% in carpet padding. Selected dust samples were fractionated based on particle size, and over 80% of the Sigma(13)BDEs were associated with particles exposure of Americans to PBDEs via hand-to-mouth transfer of house dust was estimated under the central tendency exposure and reasonable maximum exposure scenarios. The results suggest that ingestion of PBDE-laden house dust via hand-to-mouth contact is likely a significant exposure pathway, especially for children.

Polybrominated diphenyl ethers (PBDEs) in the indoor and outdoor environments – A review on occurrence and human exposure

International Nuclear Information System (INIS)

Besis, Athanasios; Samara, Constantini

2012-01-01

Polybrominated diphenyl ethers (PBDEs) constitute an important group of brominated flame retardants that have been massively produced and extensively used in numerous everyday products, providing longer escape times in case of fire and thus saving lives, as well as reducing the damage of property. In recent years, PBDEs have been recognized as significant pollutants of the indoor environment. This article provides a synthesis and critical evaluation of the state of the knowledge about the occurrence of PBDEs in the indoor environment (air and dust in homes, workplaces and cars) in different countries in Europe, North America, Asia and Australia, as well as about the human exposure via indoor air inhalation and dust ingestion in comparison to outdoor air inhalation and dietary intake. - Although dietary intake is major human exposure route to PBDEs, there is sufficient body of evidence for the ubiquitous presence of these compounds in indoor air and dust, therefore for the potential for significant exposure at work, at home, as well as in closed means of transport.

Polybrominated diphenyl ethers and novel flame retardants

DEFF Research Database (Denmark)

Frederiksen, Marie; Vorkamp, Katrin; Nielsen, Jesper Bo

,4,6-tribromophenyl ether (TBP-DBPE) and dechlorane plus (DDC-CO) have been detected in the same dust samples previously analysed for PBDEs and are currently being analysed in the corresponding human milk samples. [1] Stapleon H.M., Eagle S., Sjödin A., Webster T.F. (2012). Serum PBDEs in a North Carolina Toddler...

Atmospheric concentrations of organochlorine pesticides, polybrominated diphenyl ethers and polychloronaphthalenes in Nuuk, South-West Greenland

DEFF Research Database (Denmark)

Bossi, Rossana; Skov, Henrik; Vorkamp, Katrin

2008-01-01

Atmospheric concentrations of organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDEs) and polychloronaphthalenes (PCNs) were measured for the first time in Nuuk, Greenland in 2004 and 2005. The annual mean concentrations af the measured OCs were: α-HCH 20.2 pg m-3, Υ-HCH (lindane) 5......-HCH, which had maximum concentration in August in both years. The average annual mean for ΣPBDEs was 1.14 ± 0.81 pg m-3. The predominant congeners measured in Nuuk were BDE-47 and BDE-99 followed by BDE-100, -153 and -28, indicating the use of penta-BDE technical products as the main source. A clear seasonal...

Occurrence of polybrominated diphenyl ethers (PBDEs) in brown trout bile and liver from Swiss rivers

Energy Technology Data Exchange (ETDEWEB)

Hartmann, Paul C. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, P.O. Box 611, 8600 Duebendorf (Switzerland); Burkhardt-Holm, Patricia [Department of Environmental Science, University of Basel, Vesalgasse 1, 4051 Basel (Switzerland)]. E-mail: patricia.holm@unibas.ch; Giger, Walter [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, P.O. Box 611, 8600 Duebendorf (Switzerland)]. E-mail: giger@eawag.ch

2007-03-15

The ranges of total polybrominated diphenyl ethers (PBDEs) in fish from four Swiss rivers were 0.8-240 ng/g in the bile and 16-7400 ng/g lipid in the liver. PBDE concentrations varied within each river and among the various rivers. Female fish tended to have higher concentrations in the liver, while the male fish had higher concentrations in the bile. From the resulting PBDE concentrations in fish it could not be infered that these contaminants contribute to the causes of the observed fish catch decline in Swiss rivers. - PBDEs with the most abundant BDE-47 were determined in brown trout bile and liver from Swiss rivers.

Occurrence of polybrominated diphenyl ethers (PBDEs) in brown trout bile and liver from Swiss rivers

International Nuclear Information System (INIS)

Hartmann, Paul C.; Burkhardt-Holm, Patricia; Giger, Walter

2007-01-01

The ranges of total polybrominated diphenyl ethers (PBDEs) in fish from four Swiss rivers were 0.8-240 ng/g in the bile and 16-7400 ng/g lipid in the liver. PBDE concentrations varied within each river and among the various rivers. Female fish tended to have higher concentrations in the liver, while the male fish had higher concentrations in the bile. From the resulting PBDE concentrations in fish it could not be infered that these contaminants contribute to the causes of the observed fish catch decline in Swiss rivers. - PBDEs with the most abundant BDE-47 were determined in brown trout bile and liver from Swiss rivers

Sample preparation method for the speciation of polybrominated diphenyl ethers and their methoxylated and hydroxylated analogues in diverse environmental matrices.

Science.gov (United States)

Sun, Jianteng; Liu, Jiyan; Liu, Qian; Qu, Guangbo; Ruan, Ting; Jiang, Guibin

2012-01-15

A reliable analytical method was developed here for the simultaneous separation, identification and quantification of ten polybrominated diphenyl ethers (PBDEs), nine methoxylated PBDEs (MeO-PBDEs) and ten hydroxylated PBDEs (OH-PBDEs) in various environmental matrices, including water, soil, sediment, plant, mollusk and fish. PBDEs and MeO-PBDEs were measured by gas chromatography coupled with mass spectrometry (GC/MS) and liquid chromatography coupled with electrospray ionization (negative)-tandem quadrupole mass spectrometry (LC/ESI(-)-MS/MS) for the separation and determination of OH-PBDEs without prior derivatization. After preliminary sample cleaning using acid silica gel, water-impregnated silica column separation of PBDEs, MeO-PBDEs and OH-PBDEs was proved to be rapid, simple, and efficient. For phenolic analytes, the method detection limits (MDLs) were 3.2-11.6pg/L in water sample and 2.8-18.4pg/g dry weight in solid samples. For neutral compounds, MDLs were 48.8-150.3pg/L in water sample and 46.5-170.8pg/g dry weight in solid samples. The method was validated using six kinds of environmental samples spiked with all analytes at three concentration levels (0.3ng, 2ng and 5ng, respectively) for recovery (71-113%) and repeatability determination (4-12%RSD). Copyright © 2011 Elsevier B.V. All rights reserved.

Body burdens of polybrominated diphenyl ethers among urban anglers.

Science.gov (United States)

Morland, Kimberly B; Landrigan, Philip J; Sjödin, Andreas; Gobeille, Alayne K; Jones, Richard S; McGahee, Ernest E; Needham, Larry L; Patterson, Donald G

2005-12-01

Polybrominated diphenyl ethers (PBDEs) have been widely used in the United States and worldwide as flame retardants. Recent PBDE production figures show that worldwide use has increased. To determine whether fish consumption is a source of PBDE exposure for humans, a cross-sectional epidemiologic study of New York and New Jersey urban anglers was conducted during the summers of 2001-2003. Frequency of local fish consumption was assessed by questionnaire, and blood samples for PBDE analysis were collected from 94 anglers fishing from piers on the lower Hudson River and Newark Bay. We analyzed PBDEs by gas chromatography-isotope dilution-high-resolution mass spectrometry. The congeners found in anglers' serum at the highest concentrations were, by International Union of Pure and Applied Chemistry numbers, BDE-47, BDE-153, and BDE-99. Anglers reporting consumption of local fish had higher, but nonstatistically significantly different, concentrations of PBDEs than did anglers who did not eat local fish. For some congeners (BDE-100 and BDE-153), we observed moderate dose-response relationships between serum PBDE levels and frequency of reported fish intake. These findings suggest that consumption of locally caught fish is not a major route of human exposure for this study population.

Determination of average molecular weights on organic reactor coolants. II.-Freezing point depression method for diphenyl-ether solutions; Determinacion de masas moleculares medias en refrigerantes nucleares organicos. II.- Crioscopia de disoluciones en eter difenilico

Energy Technology Data Exchange (ETDEWEB)

Carreira, M

1965-07-01

In order to reduce limitations of solubility, the cryoscopic method developed for benzene solutions of polyphenyl mixtures has been extended to diphenyl-ether solutions by introducing some modifications imposed by the physico-chemical properties of this solvent. The Nernsto theory of Beckman's method has been revised, taking into account the heat-transfer characteristics of the system, and the results of that analysis have been used to fix upon the design parameters of a cryoscopic apparatus for measurements on diphenyl-ether solutions. (Author) 9 refs.

Determination of average molecular weights on organic reactor coolants. II.-Freezing point depression method for diphenyl-ether solutions; Determinacion de masas moleculares medias en refrigerantes nucleares organicos. II.- Crioscopia de disoluciones en eter difenilico

Energy Technology Data Exchange (ETDEWEB)

Carreira, M.

1965-07-01

In order to reduce limitations of solubility, the cryoscopic method developed for benzene solutions of polyphenyl mixtures has been extended to diphenyl-ether solutions by introducing some modifications imposed by the physico-chemical properties of this solvent. The Nernsto theory of Beckman's method has been revised, taking into account the heat-transfer characteristics of the system, and the results of that analysis have been used to fix upon the design parameters of a cryoscopic apparatus for measurements on diphenyl-ether solutions. (Author) 9 refs.

A point mutation of valine-311 to methionine in Bacillus subtilis protoporphyrinogen oxidase does not greatly increase resistance to the diphenyl ether herbicide oxyfluorfen.

Science.gov (United States)

Jeong, Eunjoo; Houn, Thavrak; Kuk, Yongin; Kim, Eun-Seon; Chandru, Hema Kumar; Baik, Myunggi; Back, Kyoungwhan; Guh, Ja-Ock; Han, Oksoo

2003-10-01

In an effort to asses the effect of Val311Met point mutation of Bacillus subtilis protoporphyrinogen oxidase on the resistance to diphenyl ether herbicides, a Val311Met point mutant of B. subtilis protoporphyrinogen oxidase was prepared, heterologously expressed in Escherichia coli, and the purified recombinant Val311Met mutant protoporphyrinogen oxidase was kinetically characterized. The mutant protoporphyrinogen oxidase showed very similar kinetic patterns to wild type protoporphyrinogen oxidase, with slightly decreased activity dependent on pH and the concentrations of NaCl, Tween 20, and imidazole. When oxyfluorfen was used as a competitive inhibitor, the Val311Met mutant protoporphyrinogen oxidase showed an increased inhibition constant about 1.5 times that of wild type protoporphyrinogen oxidase. The marginal increase of the inhibition constant indicates that the Val311Met point mutation in B. subtilis protoporphyrinogen oxidase may not be an important determinant in the mechanism that protects protoporphyrinogen oxidase against diphenyl ether herbicides.

Trifluoromethylation of graphene

Directory of Open Access Journals (Sweden)

Lin Zhou

2014-09-01

Full Text Available We demonstrate trifluoromethylation of graphene by copper-catalyzed free radical reaction. The covalent addition of CF3 to graphene, which changes the carbon atom hybridization from sp2 to sp3, and modifies graphene in a homogeneous and nondestructive manner, was verified with Raman spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. X-ray photoelectron spectroscopy reveals that CF3 groups are grafted to the basal plane of graphene, with about 4 at. % CF3 coverage. After trifluoromethylation, the average resistance increases by nearly one order of magnitude, and an energy gap of about 98 meV appears. The noninvasive and mild reaction to synthesize trifluoromethylated graphene paves the way for graphene's applications in electronics and biomedical areas.

Trifluoromethylation of graphene

Energy Technology Data Exchange (ETDEWEB)

Zhou, Lin; Zhou, Lushan; Wang, Xi; Yu, Jingwen; Yang, Mingmei; Wang, Jianbo; Peng, Hailin, E-mail: zfliu@pku.edu.cn, E-mail: hlpeng@pku.edu.cn; Liu, Zhongfan, E-mail: zfliu@pku.edu.cn, E-mail: hlpeng@pku.edu.cn [Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

2014-09-01

We demonstrate trifluoromethylation of graphene by copper-catalyzed free radical reaction. The covalent addition of CF{sub 3} to graphene, which changes the carbon atom hybridization from sp{sup 2} to sp{sup 3}, and modifies graphene in a homogeneous and nondestructive manner, was verified with Raman spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. X-ray photoelectron spectroscopy reveals that CF{sub 3} groups are grafted to the basal plane of graphene, with about 4 at. % CF{sub 3} coverage. After trifluoromethylation, the average resistance increases by nearly one order of magnitude, and an energy gap of about 98 meV appears. The noninvasive and mild reaction to synthesize trifluoromethylated graphene paves the way for graphene's applications in electronics and biomedical areas.

Human exposure to polybrominated diphenyl ethers at production area, China.

Science.gov (United States)

Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian

2010-05-01

The concentrations of polybrominated diphenyl ethers (PBDEs) were detected in air and aquatic products in PBDEs production areas which are located at the south coast area of Laizhou Bay, Shandong province, China in this study. Concentrations of SigmaPBDEs in the air ranged from 0.47 ng/m3 to 161 ng/m3. In aquatic products, concentrations of SigmaPBDEs ranged from 2.7 ng/g wet weight to 42 ng/g wet weight. The mean dietary intake of SigmaPBDEs via aquatic products consumption in this study was 218 ng/day. Daily intake of SigmaPBDEs via inhalation in this study was 612 ng for men and 455 ng for women. With a contribution of 80%, BDE-209 was predominant in the total intake. Dietary intake and breathing inhalation contributed 29 and 71%, respectively, to the total PBDEs intake. The results indicate that breathing inhalation also plays a very significant pathway for the population of the PBDEs production area. Compared with similar studies in other countries, human exposure to PBDEs via diet and inhalation in this study was the highest in the world. Copyright (c) 2010 SETAC.

The antimalarial activities of methylene blue and the 1,4-naphthoquinone 3-[4-(trifluoromethyl)benzyl]-menadione are not due to inhibition of the mitochondrial electron transport chain.

Science.gov (United States)

Ehrhardt, Katharina; Davioud-Charvet, Elisabeth; Ke, Hangjun; Vaidya, Akhil B; Lanzer, Michael; Deponte, Marcel

2013-05-01

Methylene blue and a series of recently developed 1,4-naphthoquinones, including 3-[4-(substituted)benzyl]-menadiones, are potent antimalarial agents in vitro and in vivo. The activity of these structurally diverse compounds against the human malaria parasite Plasmodium falciparum might involve their peculiar redox properties. According to the current theory, redox-active methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione are "subversive substrates." These agents are thought to shuttle electrons from reduced flavoproteins to acceptors such as hemoglobin-associated or free Fe(III)-protoporphyrin IX. The reduction of Fe(III)-protoporphyrin IX could subsequently prevent essential hemoglobin digestion and heme detoxification in the parasite. Alternatively, owing to their structures and redox properties, methylene blue and 1,4-naphthoquinones might also affect the mitochondrial electron transport chain. Here, we tested the latter hypothesis using an established system of transgenic P. falciparum cell lines and the antimalarial agents atovaquone and chloroquine as controls. In contrast to atovaquone, methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione do not inhibit the mitochondrial electron transport chain. A systematic comparison of the morphologies of drug-treated parasites furthermore suggests that the three drugs do not share a mechanism of action. Our findings support the idea that methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione exert their antimalarial activity as redox-active subversive substrates.

Photochemical Formation of Hydroxylated Polybrominated Diphenyl Ethers (OH-PBDEs) from Polybrominated Diphenyl Ethers (PBDEs) in Aqueous Solution under Simulated Solar Light Irradiation.

Science.gov (United States)

Zhao, Qian; Zhao, Huimin; Quan, Xie; He, Xin; Chen, Shuo

2015-08-04

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are of great concern due to their higher toxicity compared to PBDEs. However, the abiologic process whereby PBDEs are converted to OH-PBDEs in the aquatic environment is not well understood. To explore the possibility of OH-PBDEs photoformation in natural water, the photohydroxylation of BDE-47 has been investigated in aqueous Fe(III) and/or fulvic acid (FA) solutions and in natural lake water under simulated solar light irradiation. The results showed that 6-OH-BDE-47 and 2'-OH-BDE-68 were generated from BDE-47 under these conditions. Based on the identification of derivatives and reactive radicals, OH-PBDEs formation can be ascribed to an addition reaction of ortho-tetra-BDE radical and hydroxyl radical ((•)OH), with or without a subsequent Smiles rearrangement reaction. Since the ortho-tetra-BDE radical could be readily produced by the photolysis of BDE-47, even in pure water, (•)OH production was considered as critical for the photoformation of OH-PBDEs. Thus, it is reasonable to deduce that the photoreactive components (Fe(III), FA) in aqueous solution played an important role through influencing (•)OH generation. Although the yields of OH-PBDEs did not increase regularly with increasing concentration of these photoreactive components in solution, this study suggests a possible abiotic origin of OH-PBDEs formation in the aquatic environment.

Phenyl ethers from cultured lichen mycobionts of Graphis scripta var. serpentina and G. rikuzensis.

Science.gov (United States)

Takenaka, Yukiko; Tanahashi, Takao; Nagakura, Naotaka; Hamada, Nobuo

2003-07-01

Spore-derived mycobionts of the lichen Graphis scripta var. serpentina and G. rikuzensis were cultivated on a malt-yeast extract medium supplemented with 10% sucrose and their metabolites were investigated. 3,3'-Dihydroxy-5,5'-dimethyldiphenyl ether was isolated from the cultures of the mycobionts of G. scripta var. serpentina, while a new phenyl ether, rikuzenol, along with two known diphenyl ethers, violaceol-I and violaceol-II, were isolated from those of G. rikuzensis. The structure of the new compound was determined by spectroscopic methods. Violaceol-I was chemically synthesized and interconversion between violaceol-I and violaceol-II was proven.

Atmospheric concentrations of organochlorine pesticides, polybrominated diphenyl ethers and polychloronaphthalenes in Nuuk, South-West Greenland

Science.gov (United States)

Bossi, Rossana; Skov, Henrik; Vorkamp, Katrin; Christensen, Jesper; Rastogi, Suresh C.; Egeløv, Axel; Petersen, Dorthe

Atmospheric concentrations of organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDEs) and polychloronaphthalenes (PCNs) were measured for the first time in Nuuk, Greenland in 2004 and 2005. The annual mean concentrations of the measured OCs were: α-HCH 20.2 pg m -3, γ-HCH (lindane) 5.1 pg m -3, endosulfan 4.8 pg m -3 and dieldrin 1.9 pg m -3. Concentrations of Σ-chlordanes, DDEs and heptachlor epoxide were generally similar and lower than those of α-HCH and γ-HCH. The concentrations of most chlorinated pesticides did not show any clear seasonal variation, with the exception of γ-HCH, which had maximum concentration in August in both years. The average annual mean for ΣPBDEs was 1.14 ± 0.81 pg m -3. The predominant congeners measured in Nuuk were BDE-47 and BDE-99 followed by BDE-100, -153 and -28, indicating the use of penta-BDE technical products as the main source. A clear seasonal variation of PBDE concentrations was observed with maximum concentrations occurring in the summer months. The ΣPCNs concentrations ranged between 0.062 and 0.258 pg m -3 with an annual mean concentration of 0.161 ± 0.004 pg m -3. The PCNs profile was dominated by the tetra-PCNs (74% of the annual mean) and the penta-PCNs (18% of the annual mean). A seasonal trend for ΣPCNs was not observed. Atmospheric concentrations of the investigated compounds were correlated with temperature and anthropogenic CO in order to obtain information about their transport pattern. Positive correlations were found between CO and chlordanes, p, p'-DDE and trifluralin, while a negative correlation was found for γ-HCH. A significant correlation with temperature variations was found for dieldrin, heptachlor epoxide, α-HCH, γ-HCH, BDE-47, BDE-99 and tetra-PCNs, which indicates that re-emission of these compounds from previously contaminated surfaces as an important factor for the observed variations in concentrations.

Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

KAUST Repository

Batool, Farhat

2016-11-18

Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

KAUST Repository

Batool, Farhat; Emwas, Abdul-Hamid M.; Gao, Xin; Munawar, Munawar A.; Chotana, Ghayoor A.

2016-01-01

Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

Halogenated fatty acids

DEFF Research Database (Denmark)

Mu, Huiling; Sundin, Peter; Wesén, Clas

1997-01-01

Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation......), atomic emission spectrometry, and mass spectrometry. For most environmental samples, chlorinated FAMEs must be enriched prior to GC. ELCD is a useful detection method for indicating halogenated FAMEs in the chromatograms, and tentative identification of the halogenated species can be obtained...

Polychlorinated biphenyls and polybrominated diphenyl ethers in the North American atmosphere

International Nuclear Information System (INIS)

Shen Li; Wania, Frank; Lei, Ying D.; Teixeira, Camilla; Muir, Derek C.G.; Xiao, Hang

2006-01-01

To assess the spatial concentration variability of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the atmosphere on a large continental scale, their annually integrated air concentrations were determined in 2000/2001 using XAD-based passive air samplers (PAS). The network included 40 stations in Canada, the United States, Mexico, Belize and Costa Rica, and covered 72 degrees of latitude and longitude. Total concentrations of PCB and PBDE congeners ranged from below the detection limit to 130 ng PAS -1 and 24 ng PAS -1 , respectively. PCBs displayed a large variation between urban, rural and remote sites, whereas PBDEs did not follow such a pattern. Open burning of 'Penta'-containing waste may have contributed to the PBDEs detected in the air samples from rural and remote areas. Air from the Canadian Arctic had a relatively higher percentage of lighter PCB congeners than air sampled in the tropical region, which is interpreted as evidence for global fractionation. - A continental passive air sampling network reveals atmospheric distribution patterns of two classes of industrial chemicals

Discovery of Quinoline-Derived Trifluoromethyl Alcohols, Determination of Their in vivo Toxicity and Anticancer Activity in a Zebrafish Embryo Model.

Science.gov (United States)

Sittaramane, Vinoth; Padgett, Jihan; Salter, Philip; Williams, Ashley; Luke, Shauntelle; McCall, Rebecca; Arambula, Jonathan F; Graves, Vincent B; Blocker, Mark; Van Leuven, David; Bowe, Keturah; Heimberger, Julia; Cade, Hannah C; Immaneni, Supriya; Shaikh, Abid

2015-11-01

In this study the rational design, synthesis, and anticancer activity of quinoline-derived trifluoromethyl alcohols were evaluated. Members of this novel class of trifluoromethyl alcohols were identified as potent growth inhibitors in a zebrafish embryo model. Synthesis of these compounds was carried out with an sp(3) -C-H functionalization strategy of methyl quinolines with trifluoromethyl ketones. A zebrafish embryo model was also used to explore the toxicity of ethyl 4,4,4-trifluoro-3-hydroxy-3-(quinolin-2-ylmethyl)butanoate (1), 2-benzyl-1,1,1-trifluoro-3-(quinolin-2-yl)propan-2-ol (2), and trifluoro-3-(isoquinolin-1-yl)-2-(thiophen-2-yl)propan-2-ol (3). Compounds 2 and 3 were found to be more toxic than compound 1; apoptotic staining assays indicated that compound 3 causes increased cell death. In vitro cell proliferation assays showed that compound 2, with an LC50 value of 14.14 μm, has more potent anticancer activity than cisplatin. This novel class of inhibitors provides a new direction in the discovery of effective anticancer agents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Environmental pollution of polybrominated diphenyl ethers from industrial plants in China: a preliminary investigation.

Science.gov (United States)

Deng, Chao; Chen, Yuan; Li, Jinhui; Li, Ying; Li, Huafen

2016-04-01

Although numerous studies have shown the presence of polybrominated diphenyl ethers (PBDEs) in various environmental media, attention to their distribution in the environmental media surrounding industrial facilities is limited. In this study, eight PBDEs congeners (BDE-28, -47, -99, -100, -153, -154, -183, -209) were investigated in surface soils and water samples collected from commercial PBDE manufacturers, flame-retardant plastic modification plants and waste electrical and electronic equipment recycling facilities in China. Analysis of target compounds was performed using the model NCI GC-MS in SIM mode. The concentrations of ∑8PBDEs varied from 193.1 to 22,004.3 ng/L in water samples and from 1209.3 to 226,906 ng/g dry wt in surface soils, respectively. More severe PBDE contamination, when compared with previously reported data, was found in industrial areas in this study. This indicates that these industrial areas are highly polluted with PBDEs. BDE-209 was the predominant congener, accounting for more than 94% in this study, except for a 68.75% portion at one site. Our results show that PBDE manufacturing and flame-retardant plastic modification plants, easily overlooked by the public, are two primary PBDE pollution sources although they affect surrounding areas. Further research is needed, aimed at managing industrial PBDE emissions and eliminating environmental PBDE pollution, to investigate the material flows and environmental fates of PBDEs in all stages of the life cycle.

Halogenated methyl-phenyl ethers (anisoles) in the environment: determination of vapor pressures, aqueous solubilities, Henry's law constants, and gas/water- (Kgw), n-octanol/water- (Kow) and gas/n-octanol (Kgo) partition coefficients.

Science.gov (United States)

Pfeifer, O; Lohmann, U; Ballschmiter, K

2001-11-01

Halogenated methyl-phenyl ethers (methoxybenzenes, anisoles) are ubiquitous organics in the environment although they are not produced in industrial quantities. Modelling the fate of organic pollutants such as halogenated anisoles requires a knowledge of the fundamental physico-chemical properties of these compounds. The isomer-specific separation and detection of 60 of the 134 possible congeners allowing an environmental fingerprinting are reported in this study. The vapor pressure p0(L) of more than 60 and further physico-chemical properties of 26 available congeners are given. Vapor pressures p0(L), water solubilities S(L)W, and n-octanol/water partition coefficients Kow were determined by capillary HR-GC (High Resolution Gas Chromatography) on a non-polar phase and by RP-HPLC (Reversed Phase High Performance Liquid Chromatography) on a C18 phase with chlorobenzenes as reference standards. From these experimental data the Henry's law constants H, and the gas/water Kgw and gas/n-octanol Kgo partition coefficients were calculated. We found that vapor pressures, water solubilities, and n-octanol/water partition coefficients of the halogenated anisoles are close to those of the chlorobenzenes. A similar environmental fate of both groups can, therefore, be predicted.

Biosynthesis of hydroxylated polybrominated diphenyl ethers and the correlation with photosynthetic pigments in the red alga Ceramium tenuicorne.

Science.gov (United States)

Lindqvist, Dennis; Dahlgren, Elin; Asplund, Lillemor

2017-01-01

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified in a variety of marine organisms from different trophic levels indicating a large spread in the environment. There is much evidence pointing towards natural production as the major source of these compounds in nature. However, much is still not known about the natural production of these compounds. Seasonal trend studies have shown large fluctuations in the levels of OH-PBDEs in Ceramium tenuicorne from the Baltic Sea. Yet, even though indications of stimuli that can induce the production of these compounds have been observed, none, neither internal nor external, has been assigned to be responsible for the recorded fluctuations. In the present study the possible relationship between the concentration of pigments and that of OH-PBDEs in C. tenuicorne has been addressed. Significant correlations were revealed between the concentrations of all OH-PBDEs quantified and the concentrations of both chlorophyll a and Σxanthophylls + carotenoids. All of which displayed a concentration peak in mid-July. The levels of OH-PBDEs may be linked to photosynthetic activity, and hence indirectly to photosynthetic pigments, via bromoperoxidase working as a scavenger for hydrogen peroxide formed during photosynthesis. Yet the large apparent investment in producing specific OH-PBDE congeners point towards an targeted production, with a more specific function than being a waste product of photosynthesis. The OH-PBDE congener pattern observed in this study is not agreeable with some currently accepted models for the biosynthesis of these compounds, and indicates a more selective route than previously considered in C. tenuicorne. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sex difference in polybrominated diphenyl ether concentrations of walleyes

Science.gov (United States)

Madenjian, Charles P.; Trombka, Autumn W.; Rediske, Richard R.; Jude, David J.; O'Keefe, James P.

2012-01-01

Polybrominated diphenyl ether (PBDE) concentrations were determined for mature male and mature female walleyes (Sander vitreus) sampled from the Saginaw Bay population during 2007. PBDE concentrations in prey fish caught in the Saginaw River, the primary tributary to Saginaw Bay, and in Saginaw Bay during 2005 and 2007 also were determined. Mature male and mature female walleyes averaged 70.3 ng/g and 24.8 ng/g, respectively, in ΣPBDE, which was equal to the sum of concentrations of six PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154). This sex difference was likely due to males spending more time in the Saginaw River system than females. Prey fish captured in the Saginaw River were roughly ten times higher in ΣPBDE than those caught in Saginaw Bay. BDE-47 was the predominant congener in both walleyes and prey fish, and this congener contributed about 50%, on average, to ΣPBDE. Congener profiles differed significantly between the two sexes of walleyes. In contrast, congener profiles of the prey fish did not differ significantly between the river-caught fish and the bay-caught fish. One plausible explanation for these congener profile results was that net trophic transfer efficiencies of PBDEs to walleyes from their prey were similar for all congeners except BDE-28, and that diet composition differed between the two sexes of walleyes.

Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China.

Science.gov (United States)

Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

2016-05-01

A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC-MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEslow, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16-5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

Science.gov (United States)

Googin, J.M.; Napier, J.M.; Travaglini, M.A.

1982-03-31

A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

Synthesis of trifluoromethylated acetylenes via copper-catalyzed trifluoromethylation of alkynyltrifluoroborates

KAUST Repository

Zheng, Huidong

2012-12-01

A new method for the synthesis of trifluoromethylated acetylenes is developed which involves the copper-catalyzed trifluoromethylation of alkynyltrifluoroborates with an electrophilic trifluoromethylating reagent. This method offers significant advantages such as efficiency and mild and base-free reaction conditions. A plausible mechanism is proposed. © 2012 Elsevier Ltd. All rights reserved.

Synthesis of trifluoromethylated acetylenes via copper-catalyzed trifluoromethylation of alkynyltrifluoroborates

KAUST Repository

Zheng, Huidong; Huang, Yuanyuan; Wang, Zhiwei; Li, Huaifeng; Huang, Kuo-Wei; Yuan, Yaofeng; Weng, Zhiqiang

2012-01-01

A new method for the synthesis of trifluoromethylated acetylenes is developed which involves the copper-catalyzed trifluoromethylation of alkynyltrifluoroborates with an electrophilic trifluoromethylating reagent. This method offers significant advantages such as efficiency and mild and base-free reaction conditions. A plausible mechanism is proposed. © 2012 Elsevier Ltd. All rights reserved.

Effects of polybrominated diphenyl ethers (PBDEs) and their derivatives on protein disulfide isomerase activity and growth hormone release of GH3 cells.

Science.gov (United States)

Hashimoto, Shoko; Yoshimura, Hiromi; Okada, Kazushi; Uramaru, Naoto; Sugihara, Kazumi; Kitamura, Shigeyuki; Imaoka, Susumu

2012-03-19

Polybrominated diphenyl ethers (PBDEs) have been used in a variety of consumer products such as flame retardants and recently have been known to be widespread environmental pollutants, which probably affect biological functions of mammalian cells. However, the risk posed by PBDE metabolites has not been clarified. Our previous study suggested that bisphenol A (BPA), an endocrine-disrupting chemical, binds to protein disulfide isomerase (PDI) and inhibits its activity. PDI is an isomerase enzyme in the endoplasmic reticulum and facilitates the formation or cleavage of disulfide bonds. PDI consists of a, b, b', and a' domains and the c region, with the a and a' domains having isomerase active sites. In the present study, we tested the effects of 10 kinds of PBDE compounds and their metabolites on PDI. OH-PBDEs specifically inhibited the isomerase activity of PDI, with 4'-OH-PBDE more effective than 2' (or 2)-OH-PBDEs. 4'-OH-PBDE inhibited the isomerase activity of the b'a'c fragment but not that of ab and a'c, suggesting that the b' domain of PDI is essential for the inhibition by 4'-OH-PBDE. We also investigated the effects of these chemicals on the production of growth hormone (GH) in GH3 cells. In GH3 cells, levels of mRNA and protein of GH stimulated by T(3) were reduced by 4'-OH-PBDE and 4'-MeO-PBDE. The reduction in GH expression caused by these compounds was not changed by the overexpression or knockdown of PDI in GH3 cells, while these manipulations of PDI levels significantly suppressed the expression of GH. These results suggest that the biological effects of PBDEs differed depending on their brominated and hydroxylated positions. © 2011 American Chemical Society

Spatial distributions and temporal trends in polybrominated diphenyl ethers in Detroit River suspended sediments.

Science.gov (United States)

Marvin, Chris; Waltho, Jasmine; Jia, Julia; Burniston, Debbie

2013-05-01

Suspended sediments from the Detroit River were collected using sediment traps at sites ranging from western Lake Erie to southern Lake St. Clair to assess spatial distributions and temporal trends of polybrominated diphenyl ethers (PBDEs). The distribution of PBDEs in suspended sediments in the Detroit River appeared influenced by shoreline-based contemporary urban and industrial activities, which stood in contrast to PCBs that were associated with areas of historic industrial activity. Temporal trend data indicate that total PBDE concentrations decreased in the period after 2000 in response to cessation of production of the penta- and octa BDE formulations. Concentrations of total PBDEs ranged from roughly 7 ng g(-1) (4 ng g(-1) BDE 209) in southern Lake St. Clair to several hundred ng g(-1) (60-180 ng g(-1) BDE 209) in the lower reaches of the Detroit River. The widespread occurrence of PBDEs in Detroit River suspended sediments suggests that large urban areas can act as diffuse sources of these chemicals that are used in modern industrial applications and consumer products. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Polybrominated diphenyl ethers in indoor air during waste TV recycling process

International Nuclear Information System (INIS)

Guo, Jie; Lin, Kuangfei; Deng, Jingjing; Fu, Xiaoxu; Xu, Zhenming

2015-01-01

Graphical abstract: - Highlights: • Air in the workshops was seriously contaminated by TV recycling activities. • PBDEs profiles and levels varied with particulate matters and different workshops. • Equilibrium between gas-particle partitioning was disrupted by recycling process. • The highest occupational exposure concentrations occurred during heating process. - Abstract: Recycling process for waste TV sets mainly consists of dismantling, printed wiring board (PWB) heating, PWB recycling, and plastic crushing in formal recycling plant. Polybrominated diphenyl ethers (PBDEs) contained in waste TV sets are released to indoor air. Air samples at 4 different workshops were collected to measure the PBDEs concentrations in both gaseous and particulate phases. The mean concentrations of ∑PBDEs in indoor air were in the range of 6780–2,280,000 pg/m 3 . The highest concentration in gaseous phase (291,000 pg/m 3 ) was detected in the PWB heating workshop. The ∑ 12 PBDEs concentrations in PM 2.5 and PM 10 at the 4 workshops ranged in 6.8–6670 μg/g and 32.6–6790 μg/g, respectively. The gas-particle partitioning of PBDEs was disrupted as PBDEs were continuously released during the recycling processes. Occupational exposure assessment showed that only the exposure concentration of BDE-47 (0.118 μg/kg/day) through inhalation in the PWB heating workshop for workers without facemask exceeded the reference dose (0.1 μg/kg/day), posing a health hazard to workers. All the results demonstrated that recycling of TV sets was an important source of PBDEs emission, and PBDEs emission pollution was related to the composition of TV sets, interior dust, and recycling process

Legacy and alternative halogenated flame retardants in human milk in Europe: Implications for children's health.

Science.gov (United States)

Čechová, Eliška; Vojta, Šimon; Kukučka, Petr; Kočan, Anton; Trnovec, Tomáš; Murínová, Ľubica Palkovičová; de Cock, Marijke; van de Bor, Margot; Askevold, Joakim; Eggesbø, Merete; Scheringer, Martin

2017-11-01

In this study, 10 polybrominated diphenyl ethers (PBDEs) and 19 alternative halogenated flame retardants (AFRs) were determined in >450 human milk samples across three European countries, representing northern, western and eastern Europe. This study provides first insights into the occurrence of selected AFRs in mother milk samples and compares them among three European countries. Sums of median concentrations of the most frequently detected PBDEs were 2.16, 0.88 and 0.45ngg -1 lipid weight (lw) in Norway, the Netherlands and Slovakia, respectively. The sum of the concentrations of AFRs ranged from 0.14 to 0.25ngg -1 lw in all countries, which was 2 to 15 times less compared to Σ 7 PBDEs. The Penta-BDE replacement, bis(2-ethylhexyl) tetrabromophthalate, BEH-TEBP, was present at the greatest concentrations of any of the AFRs and in some samples exceeded concentrations of BDE 47 and BDE 153. Four AFRs including bromobenzenes (hexabromobenzene, pentabromobenzene, pentabromotoluene) and another Penta-BDE replacement (2-ethylhexyl-2,3,4,5-tetrabromobenzoate, EH-TBB) were detected in >42% of all human milk samples. Because of the potential developmental neurotoxicity of the halogenated flame retardants, infant dietary intakes via breastfeeding were estimated; in four cases the intakes of BDE 47 exceeded the reference dose indicating that the present concentrations may pose a risk for children. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biological Effects of Polybrominated Diphenyl Ethers in Organism and Human%多溴联苯醚的生物效应研究

Institute of Scientific and Technical Information of China (English)

齐彭德; 陆光华; 梁艳; 赵海洲

2011-01-01

多溴联苯醚(Polybrominatcd diphenyl ethers,PBDEs)由于其良好的阻燃性能被广泛应用于电子电器,家具,装饰材料及其他产品中.自使用以来,PBDEs在环境、生物体、人体中的污染水平快速增长,对生物体及人体的潜在危害日趋严重.国际社会已经认识到其危害性,部分PBDEs产品,如六溴联苯醚、七溴联苯醚、四溴联苯醚、五溴联苯醚已被列入禁用名单.文章概述PBDEs在生物体中的污染水平、生物累集效应以及PBDEs在生物体内的转化及代谢效应,着重阐述了PBDEs对神经系统、生物转化酶系统、抗氧化防御系统、生殖系统及内分泌系统的毒性效应,同时对PBDEs毒性作用机制及PBDEs环境相关污染浓度研究提出展望.%Polybrominated diphenyl ethers (PBDEs) are widely used in electronic appliances, furniture, decoration materials and other products due to its good performance of flame' retardant. PBDEs pollution level has increased rapidly in environment, organism and human, which cause seriously potential harm to the organism and human body. Their danger is recognized and several kinds of PBDEs have been added in the banned list, such as hexabromodiphenyl ether, heptabromodiphenyl ether, tetrabromodiphenyl ether and pentabromodiphenyl ether. The pollution level and biological amplification of PBDEs was summarized, the degradation and metabolic effects of PBDEs in organism were introduced. Toxic effects of PBDEs on the nervous system, biotransformation enzymes, antioxidant defense system, reproductive system, immune system and endocrine system were analyzed, and toxic mechanism of PBDEs and research of environment correlative concentration of PBDEs were also proposed.

Polybrominated diphenyl ethers enhance the production of proinflammatory cytokines by the placenta.

Science.gov (United States)

Peltier, M R; Klimova, N G; Arita, Y; Gurzenda, E M; Murthy, A; Chawala, K; Lerner, V; Richardson, J; Hanna, N

2012-09-01

Polybrominated diphenyl ether(s) (PBDE) are ubiquitous environmental contaminants that bind and cross the placenta but their effects on pregnancy outcome are unclear. It is possible that environmental contaminants increase the risk of inflammation-mediated pregnancy complications such as preterm birth by promoting a proinflammatory environment at the maternal-fetal interface. We hypothesized that PBDE would reduce IL-10 production and enhance the production of proinflammatory cytokines associated with preterm labor/birth by placental explants. Second-trimester placental explants were cultured in either vehicle (control) or 2 μM PBDE mixture of congers 47, 99 and 100 for 72 h. Cultures were then stimulated with 10(6) CFU/ml heat-killed Escherichia coli for a final 24 h incubation and conditioned medium was harvested for quantification of cytokines and PGE(2). COX-2 content and viability of the treated tissues were then quantified by tissue ELISA and MTT reduction activity, respectively. PBDE pre-treatment reduced E. coli-stimulated IL-10 production and significantly increased E. coli-stimulated IL-1β secretion. PBDE exposure also increased basal and bacteria-stimulated COX-2 expression. Basal, but not bacteria-stimulated PGE(2), was also enhanced by PBDE exposure. No effect of PBDE on viability of the explants cultures was detected. In summary, pre-exposure of placental explants to congers 47, 99, and 100 enhanced the placental proinflammatory response to infection. This may increase the risk of infection-mediated preterm birth by lowering the threshold for bacteria to stimulate a proinflammatory response(s). Copyright © 2012 Elsevier Ltd. All rights reserved.

Uptake, translocation, and debromination of polybrominated diphenyl ethers in maize

Institute of Scientific and Technical Information of China (English)

Moming Zhao; Shuzhen Zhang; Sen Wang; Honglin Huang

2012-01-01

Uptake,translocation and debromination of three polybrominated diphenyl ethers(PBDEs),BDE-28,-47 and-99,in maize were studied in a hydroponic experiment.Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability.PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants.Furthermore,PBDE concentrations decreased from roots to stems and then to leaves,and a very clear decreasing gradient was found in segments upwards along the stem.These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize.More highly brominated PBDEs were translocated with more difficulty.Radial translocation of PBDEs from nodes to sheath inside maize was also observed.Both acropetal and radial translocations were enhanced at higher transpiration rates,suggesting that PBDE transport was probably driven by the transpiration stream.Debromination of PBDEs occurred in all parts of the maize,and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences.This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants,elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.

Binding of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100) and/or its metabolites to mammalian biliary carrier proteins

Energy Technology Data Exchange (ETDEWEB)

Larsen, G.; Huwe, J.; Hakk, H. [USDA ARS Biosciences Research Lab, Fargo, ND (United States); Low, M.; Rutherford, D. [Concordia College, Moorhead, MN (United States)

2004-09-15

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in the textile and electronics industries and are globally produced in the range of 150,000 tons annually. Because they are very lipophilic, structurally similar to polychlorinated dibenzo-p-dioxins and biphenyls, environmentally persistent, and display an increasing number of toxicological effects, there is growing concern that this class of compounds may be emerging as a new environmental contaminant. Recent reports have documented their presence in human plasma, milk, and adipose tissue and in aquatic species such as sperm whales, harbor seals, and whitebeaked dolphins. Only a few PBDE congeners are consistently found and reported in the environment, e.g. BDE-47, 99, 100, 153 and 154, and 209. Of this group, only BDE-47 and 99 have been studied in mammals. Halogenated aromatic hydrocarbons can associate with endogenous carrier proteins in the urine and bile of rats, either as the parent or as metabolites. Toxic and non-toxic dioxins, PCB's, and PBDE's all have this capacity. Based on its lipophilicity, BDE-100 would be expected to require carrier proteins for mammalian in vivo transport. The purpose of the association has not been established but may be part of the process involved in mammalian elimination of these xenobiotics. However, the association may affect the normal function of these carrier proteins. One of the purposes of the present research was to administer a single oral dose of BDE-100 to male rats and measure the amount eliminated in the urine and bile, as well as characterize the nature and extent of binding to any proteins in these excreta.

Polybrominated diphenyl ethers (PBDEs) and thyroid hormones in cord blood

International Nuclear Information System (INIS)

Ding, Guodong; Yu, Jing; Chen, Limei; Wang, Caifeng; Zhou, Yijun; Hu, Yi; Shi, Rong; Zhang, Yan; Cui, Chang; Gao, Yu; Tian, Ying; Liu, Fang

2017-01-01

Human exposure to polybrominated diphenyl ethers (PBDEs) has been increasing over the last three decades in China and around the world. Animal studies suggest that PBDEs could reduce blood levels of thyroid hormones, but it is unclear whether PBDEs disrupt thyroid function in humans. We used data from a prospective birth cohort of 123 pregnant women who were enrolled between September 2010 and March 2011 in Shandong, China. We measured the concentrations of eight PBDE congeners (n = 106) and five thyroid hormones (n = 107) in cord serum samples. We examined the relationship between prenatal exposure to PBDEs and thyroid function (n = 90). Median concentrations of BDEs 47, 99, 100, and 153 (detection frequencies > 75%) were 3.96, 8.27, 3.31, and 1.89 ng/g lipid, respectively. A 10-fold increase in BDE-99 and Σ 4 PBDEs (the sum of BDEs 47, 99, 100, and 153) concentrations was associated with a 0.41 μg/dL (95% confidence interval [CI]: 0.10 to 0.72) and 0.37 μg/dL (95% CI: 0.06 to 0.68) increase in total thyroxine levels (TT 4 ), respectively. No associations were found between other individual congeners and any of the five thyroid hormones. Our study suggests that prenatal exposure to PBDEs may be associated with higher TT 4 in cord blood. Given the inconsistent findings across existing studies, our results need to be confirmed in additional studies. - Highlights: • Human exposure to PBDEs has been increased over recent decades in China. • PBDEs reduce thyroid hormones in animal studies, but it is unclear in humans. • We examined the relation of PBDE levels with thyroid hormones in cord blood. • Prenatal exposure to PBDEs is associated with higher total thyroxine levels. • The findings may have implications for fetal development. - Exposure to PBDEs is associated with higher total thyroxine levels in cord blood, and the findings may have implications for fetal development.

Presence of polybrominated diphenyl ethers in Spanish sewage sludges. Important contribution of deca-BDE

Energy Technology Data Exchange (ETDEWEB)

Fabrellas, B.; Larrazabal, D.; Martinez, M.A. [CIEMAT, Madrid (Spain); Eljarrat, E.; Barcelo, D. [I.I.Q.A.B., C.S.I.C, Barcelona (Spain)

2004-09-15

Introduction Polybrominated diphenyl ethers (PBDE) are a family of synthetic chemicals widely used in industry to delay, inhibit or even suppress combustion process in manufactured items. Flame retardant products are frequently added into plastic, electronic, paint and textile materials to reduce the risk of ignition. During last years, increasing levels of PBDE have been detected in the environment, suggesting release from the treated surface as main pathway for environmental intake. Their physicochemical structure make them substances of highly lypophylic, bioaccumulative and persistent nature, with potential toxic effects observed onto wildlife and humans. Some European countries (Switzerland and Sweden) have promoted strategies to enlarge the knowledge of PBDE, in particular their occurrence and levels on sewage sludge. Observations point domestic washing of garment/clothes and industrial discharges from plastic and textile manufacture industry as major sources of contamination. First European results from 1988 revealed levels of about 20-30 {mu}g/kg dw of PBDEs (BDEs 47, 99 and 100) in sludge samples collected in Sweden. More recently, another Swedish survey conducted on three waste-water treatment facilities pointed levels of PBDE (BDE 47, 99 and 209) of about 200 ng/g dw, along with minor contribution of other contaminants such as TBBPA and HBCD iv. Few studies have been carried out in US. Hale et al. compared levels of Tetra-, PentaBDE (BDE 47, BDE 99 and BDE 100) and DecaBDE 209 congeners in sludge from different US locations. Values ranged from 1000 to 2290 {mu}g/kg dw (Tri- to HexaBDE) and from 84 to 4890 {mu}g/kg dw for DecaBDE 209, with mean values of about 1600 and 1000 {mu}g/kg dw, respectively. In general, concentrations of BDE 47, 99, 100 and 209 exceeded those of the major PCB congeners and other halogenated contaminants also found in the sludge. Following this trend, this work aims a preliminary assessment of selected PBDE congener levels on

Exposure of alveolar macrophages to polybrominated diphenyl ethers suppresses the release of pro-inflammatory products in vitro.

Science.gov (United States)

Hennigar, Stephen R; Myers, Jay L; Tagliaferro, Anthony R

2012-04-01

Inhalation of chemical pollutants has been associated with a reduced immune response in humans. Inhalation of dust is a major route of exposure for one endocrine-disrupting chemical and suspected xenoestrogen, polybrominated diphenyl ethers (PBDEs); however, the impact of PBDEs on immune function is unclear. The objective of this study was to investigate the action of PBDEs on cytokine and eicosanoid release by alveolar macrophages and determine whether the effects are mediated via the estrogen receptor. The production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, IL-10 and prostaglandin E(2) (PGE(2)) by porcine alveolar macrophages exposed to different concentrations of the pentabrominated diphenyl ether mixture, DE-71, were measured; cells were also exposed to varying concentrations of 17β-estradiol and the selective estrogen receptor-modulating agent, tamoxifen. Cells exposed to PBDEs released significantly less pro-inflammatory cytokines (TNF-α and IL-6) and PGE(2) compared with controls; IL-1β and IL-10 were not detected in the culture medium. Cells exposed to 17β-estradiol released significantly less TNF-α compared with controls, an effect that was reversed by the addition of tamoxifen; tamoxifen had no effect on the inhibition of TNF-α release by PBDEs. Although the suppression of TNF-α with DE-71 was similar to that of estrogen, the inhibitory effects of DE-71 were not found to be dependent on the estrogen receptor. Findings of this study suggest that chronic exposure to PBDEs suppressed innate immunity in vitro. Whether the immunosuppressant effects of PBDEs occur in vivo, remains to be determined.

Special distribution of polybrominated diphenyl ethers in brain tissues of free-range domestic hens and ducks from a village near an electronic waste recycling site in South China.

Science.gov (United States)

Yang, Zhong-Zhi; Li, Yong-Fang; Fu, Shan; Zhao, Xing-Ru

2011-03-01

The rural village, Taizhou of Zhejiang Province, had been exposed to e-waste recycling for years, the polybrominated diphenyl ether (PBDE) levels in hens and ducks were high. The concentration of ∑PBDEs in the brain was the lowest among tissues of individual hens and ducks after correction for the respective lipid content. Also, the concentration ratio of BDE-153 versus BDE-154 (153/154) of brain was the highest among tissues of individual hens and ducks. Our results indicate that the hindrance of blood-brain barrier to compounds, such as high molecular weight and non-planar conformation (steric hindrance), contributed to the low concentration of PBDEs in the brain tissue of hens and ducks, especially in cases exposed to high levels of PBDE.

Quantitative prediction of solvation free energy in octanol of organic compounds.

Science.gov (United States)

Delgado, Eduardo J; Jaña, Gonzalo A

2009-03-01

The free energy of solvation, DeltaGS0, in octanol of organic compounds is quantitatively predicted from the molecular structure. The model, involving only three molecular descriptors, is obtained by multiple linear regression analysis from a data set of 147 compounds containing diverse organic functions, namely, halogenated and non-halogenated alkanes, alkenes, alkynes, aromatics, alcohols, aldehydes, ketones, amines, ethers and esters; covering a DeltaGS0 range from about -50 to 0 kJ.mol(-1). The model predicts the free energy of solvation with a squared correlation coefficient of 0.93 and a standard deviation, 2.4 kJ.mol(-1), just marginally larger than the generally accepted value of experimental uncertainty. The involved molecular descriptors have definite physical meaning corresponding to the different intermolecular interactions occurring in the bulk liquid phase. The model is validated with an external set of 36 compounds not included in the training set.

Polybrominated diphenyl ethers in pinnipeds stranded along the southern California coast

Energy Technology Data Exchange (ETDEWEB)

Meng Xiangzhou [Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626 (United States); Blasius, Mary Ellen; Gossett, Richard W. [Institute for Integrated Research in Materials, Environments and Society (IIRMES), California State University, Long Beach, 1250 Bellflower Blvd, Long Beach, CA 90840 (United States); Maruya, Keith A., E-mail: keithm@sccwrp.or [Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626 (United States)

2009-10-15

Little to no information exists for polybrominated diphenyl ethers (PBDEs) in marine mammals frequenting the highly urbanized southern California (USA) coast. Fourteen PBDE congeners were determined by GC-ECNI-MS in blubber of pinnipeds stranded locally between 1994 and 2006. Total PBDE concentrations (SIGMAPBDE) in California sea lion (n = 63) ranged from 0.04 to 33.7 mug/g wet weight (mean: 5.24 mug/g). To our knowledge, these are the highest reported PBDE levels in marine mammals to date. By comparison, mean SIGMAPBDE in Pacific harbor seals (n = 9) and northern elephant seals (n = 16) were 0.96 and 0.09 mug/g, respectively. PBDEs in adult males were higher than for adult females, however, no age class differences or temporal trends were observed. As the first PBDE data reported for marine mammals in this region, the elevated levels underscore the need for additional studies on the sources, temporal trends, and potential effects of PBDEs in highly urbanized coastal zones. - Levels of PBDEs in pinnipeds found stranded along the southern California coast (USA) between 1994 and 2006 are the highest reported to date for marine mammals.

Polybrominated diphenyl ethers in pinnipeds stranded along the southern California coast

International Nuclear Information System (INIS)

Meng Xiangzhou; Blasius, Mary Ellen; Gossett, Richard W.; Maruya, Keith A.

2009-01-01

Little to no information exists for polybrominated diphenyl ethers (PBDEs) in marine mammals frequenting the highly urbanized southern California (USA) coast. Fourteen PBDE congeners were determined by GC-ECNI-MS in blubber of pinnipeds stranded locally between 1994 and 2006. Total PBDE concentrations (ΣPBDE) in California sea lion (n = 63) ranged from 0.04 to 33.7 μg/g wet weight (mean: 5.24 μg/g). To our knowledge, these are the highest reported PBDE levels in marine mammals to date. By comparison, mean ΣPBDE in Pacific harbor seals (n = 9) and northern elephant seals (n = 16) were 0.96 and 0.09 μg/g, respectively. PBDEs in adult males were higher than for adult females, however, no age class differences or temporal trends were observed. As the first PBDE data reported for marine mammals in this region, the elevated levels underscore the need for additional studies on the sources, temporal trends, and potential effects of PBDEs in highly urbanized coastal zones. - Levels of PBDEs in pinnipeds found stranded along the southern California coast (USA) between 1994 and 2006 are the highest reported to date for marine mammals.

Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China

International Nuclear Information System (INIS)

Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

2016-01-01

A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC–MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEs_l_o_w_, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16–5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. - Highlights: • This is the first study concentrating specifically on PBDEs in the study area. • The commercial Penta/Octa/Deca-BDE products were the possible sources. • The debromination of highly brominated PBDEs were also found to be the sources. • Scientific attention should not be reduced on these outdated chemical compounds. - The commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds were found to be the possible sources.

Polybrominated diphenyl ethers (PBDEs) in the indoor environment and associations with prenatal exposure

DEFF Research Database (Denmark)

Vorkamp, Katrin; Thomsen, Marianne; Frederiksen, Marie

2011-01-01

As part of a larger exposure study, samples of dust and indoor air were collected in the homes of 43 pregnant women living in the Copenhagen area (Denmark) and analysed for 12 polybrominated diphenyl ethers using GC-MS. A second dust sample collected after delivery was analysed for BDE-183 and BDE...... established geographical differences between continental Europe and North America. Additional octa- and nonaBDE congeners (BDE-197, BDE-203, BDE-206, BDE-207, and BDE-208) were analysed in dust and analytical issues were discussed as these congeners also can be a product of thermal degradation of BDE-209...... further in this study. For all matrices, the PBDE profile resembled that of the technical product Bromkal 70-5DE, but air contained higher percentages of the lower brominated congeners and placenta tissue was dominated by BDE-153. The predominance of BDE-153 has been described in other studies on human...

Polybrominated diphenyl ethers in South China maternal and fetal blood and breast milk

Energy Technology Data Exchange (ETDEWEB)

Bi Xinhui [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Qu Weiyue [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Sheng Guoying [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); School of Environment and Chemical Engineering, Shanghai University, Shanghai 200072 (China); Zhang Wenbing [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Mai Bixian [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Dunjin [Obstetrical and Gynecological Institute, Guangzhou Second People' s Hospital, Guangzhou 510150 (China); Yu Lin [Obstetrical and Gynecological Institute, Guangzhou Second People' s Hospital, Guangzhou 510150 (China); Fu Jiamo [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China) and School of Environment and Chemical Engineering, Shanghai University, Shanghai 200072 (China)]. E-mail: fujm@gig.ac.cn

2006-12-15

Twenty-one-paired human fetal and maternal serum and 27 breast milk samples at South China were analyzed for concentrations of polybrominated diphenyl ethers (PBDEs). Seven PBDE congeners (BDE-28, -47, -99, -100, -153, -154, and -183) were quantified using gas chromatography/mass spectrometry (GC/MS). This is the first report to present the residue levels of PBDEs in human samples of China. The concentrations of total PBDEs ranged from 1.5 to 17 ng/g in the samples and were within the range reported in European samples for a similar population, but lower than human tissue levels in North America. BDE-47 and -153 were the dominant PBDE congeners in all samples and accounted for 60% of the total PBDEs. Further research is needed to determine the exposure route of PBDEs and their health effects. - A survey of PBDE concentrations in human blood and milk helps identify background concentrations in South China population.

Stable carbon isotope analysis (δ13C values) of polybrominated diphenyl ethers and their UV-transformation products

International Nuclear Information System (INIS)

Rosenfelder, Natalie; Bendig, Paul; Vetter, Walter

2011-01-01

Polybrominated diphenyl ethers (PBDEs) are frequently detected in food and environmental samples. We used compound specific isotope analysis to determine the δ 13 C values of individual PBDEs in two technical mixtures. Within the same technical product (DE-71 or DE-79), BDE congeners were the more depleted in 13 C the higher brominated they were. In contrast, the products of light-induced hydrodebromination of BDE 47 and technical DE-79 were more enriched in 13 C because of more stable bonds between 13 C and bromine. As a result, the δ 13 C values of the irradiated solution progressed diametrically compared to those of the technical synthesis. The ratio of the δ 13 C values of BDE 47 to BDE 99 and of BDE 99 to BDE 153 are thus suggested as indicators to distinguish native technical products from transformation products. Ratios 1) is typical of transformation products. - Highlights: → δ 13 C values of PBDEs were determined by means of compound specific isotope analysis. → PBDEs in technical mixtures were the more depleted in 13 C the higher they were brominated. → Solutions of individual PBDEs and technical PBDE mixtures were irradiated by UV light. → δ 13 C values of irradiated PBDEs and technical PBDEs progressed diametrically. → Ratios of the δ 13 C values were used to distinguish native from transformed PBDEs. - Diametrically progressing δ 13 C values in technical mixtures and UV-transformation products of DE-79 may be useful for source appointment of PBDEs in environmental samples

Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs

Science.gov (United States)

McKernan, Moira A.; Rattner, Barnett A.; Hatfield, Jeff S.; Hale, Robert C.; Ottinger, Mary Ann

2010-01-01

We recently reported that air cell administration of penta-brominated diphenyl ether (penta-BDE; DE-71) evokes biochemical and immunologic effects in chicken (Gallus gallus) embryos at very low doses, and impairs pipping (i.e., stage immediately prior to hatching) and hatching success at 1.8 ug g-1 egg (actual dose absorbed) in American kestrels (Falco sparverius). I n the present study, absorption of polybrominated diphenyl ether (PBDE) congeners was measured following air cell administration of a penta-BDE mixture (11.1 ug DE-71 g-1 egg) or an octa-brominated diphenyl ether mixture (octa-BDE; DE-79; 15.4 ug DE-79 g-1 egg). Uptake of PBDE congeners was measured at 24 h post-injection, midway through incubation, and at pipping in chicken, mallard (Anas platyrhynchos), and American kestrel egg contents, and at the end of incubation in black-crowned night-heron (Nycticorax nycticorax) egg contents. Absorption of penta-BDE and octa-BDE from the air cell into egg contents occurred throughout incubation; at pipping, up to 29.6% of penta-BDE was absorbed, but only 1.40-6.48% of octa-BDE was absorbed. Higher brominated congeners appeared to be absorbed more slowly than lower brominated congeners, and uptake rate was inversely proportional to the log Kow of predominant BDE congeners. Six congeners or co-eluting pairs of congeners were detected in penta-BDE-treated eggs that were not found in the dosing solution suggesting debromination in the developing embryo, extraembryonic membranes, and possibly even in the air cell membrane. This study demonstrates the importance of determining the fraction of xenobiotic absorbed into the egg following air cell administration for estimation of the lowest-observed-effect level.

Effects of polybrominated diphenyl ethers on steroidogenesis in rat Leydig cells.

Science.gov (United States)

Wang, Kai-Lee; Hsia, Shih-Min; Mao, I-Fang; Chen, Mei-Lien; Wang, Shyi-Wu; Wang, Paulus S

2011-08-01

Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants that have been defined as major environmental pollutants. While previous studies have found that PBDEs may enhance the levels of sex-steroid hormones, their effects on testosterone secretion from rat Leydig cells are unclear. This study investigated the effects and mechanisms of PBDE-710, a mixture of tetra- and penta-PBDEs, on testosterone biosynthesis in rat Leydig cells. Leydig cells from adult male rats were challenged with different concentrations of PBDE-710 (0.5-15 ng/ml) to evaluate the effects on testosterone steroidogenesis. Concentrations of testosterone and of cAMP and pregnenolone in medium were measured by radioimmunoassay (RIA) and by enzyme-linked immunosorbent assay, respectively. Nuclear translocation of protein kinase A α (PKAα) was determined by immunofluorence assay and western blot assay, and the mRNA expression of steroidogenic acute regulatory protein (StAR) was analyzed by quantitative real-time polymerase chain reaction. In this in vitro study, PBDE-710 (5 or 15 ng/ml) increased basal testosterone secretion and cAMP production by 3- and 2-fold, respectively. The stimulatory effect was abolished by adenylyl cyclase inhibitor. Enzyme activity of CYP11A1, as determined by the pregnenolone concentration, was stimulated by PBDE-710 treatment. Furthermore, nuclear translocation of PKAα was increased by 20% and StAR gene expression was elevated by 4-fold after PBDE-710 treatment. These results suggest that low concentrations of PBDE-710 could stimulate testosterone secretion by acting directly on Leydig cells to activate the cAMP pathway and increase expression of StAR.

Distribution of polybrominated diphenyl ethers in Japanese autopsy tissue and body fluid samples.

Science.gov (United States)

Hirai, Tetsuya; Fujimine, Yoshinori; Watanabe, Shaw; Nakano, Takeshi

2012-09-01

Brominated flame retardants are components of many plastics and are used in products such as cars, textiles, televisions, and personal computers. Human exposure to polybrominated diphenyl ether (PBDE) flame retardants has increased exponentially during the last three decades. Our objective was to measure the body burden and distribution of PBDEs and to determine the concentrations of the predominant PBDE congeners in samples of liver, bile, adipose tissue, and blood obtained from Japanese autopsy cases. Tissues and body fluids obtained from 20 autopsy cases were analyzed. The levels of 25 PBDE congeners, ranging from tri- to hexa-BDEs, were assessed. The geometric means of the sum of the concentrations of PBDE congeners having detection frequencies >50 % (ΣPBDE) in the blood, liver, bile, and adipose tissue were 2.4, 2.6, 1.4, and 4.3 ng/g lipid, respectively. The most abundant congeners were BDE-47 and BDE-153, followed by BDE-100, BDE-99, and BDE-28+33. These concentrations of PBDE congeners were similar to other reports of human exposure in Japan but were notably lower than concentrations than those reported in the USA. Significant positive correlations were observed between the concentrations of predominant congeners and ΣPBDE among the samples analyzed. The ΣPBDE concentration was highest in the adipose tissue, but PBDEs were distributed widely among the tissues and body fluids analyzed. The PBDE levels observed in the present study are similar to those reported in previous studies in Japan and significantly lower than those reported in the USA.

Excited States and Photodebromination of Selected Polybrominated Diphenyl Ethers: Computational and Quantitative Structure—Property Relationship Studies

Directory of Open Access Journals (Sweden)

Jin Luo

2015-01-01

Full Text Available This paper presents a density functional theory (DFT/time-dependent DFT (TD-DFT study on the lowest lying singlet and triplet excited states of 20 selected polybrominateddiphenyl ether (PBDE congeners, with the solvation effect included in the calculations using the polarized continuum model (PCM. The results obtained showed that for most of the brominated diphenyl ether (BDE congeners, the lowest singlet excited state was initiated by the electron transfer from HOMO to LUMO, involving a π–σ* excitation. In triplet excited states, structure of the BDE congeners differed notably from that of the BDE ground states with one of the specific C–Br bonds bending off the aromatic plane. In addition, the partial least squares regression (PLSR, principal component analysis-multiple linear regression analysis (PCA-MLR, and back propagation artificial neural network (BP-ANN approaches were employed for a quantitative structure-property relationship (QSPR study. Based on the previously reported kinetic data for the debromination by ultraviolet (UV and sunlight, obtained QSPR models exhibited a reasonable evaluation of the photodebromination reactivity even when the BDE congeners had same degree of bromination, albeit different patterns of bromination.

Polybrominated diphenyl ethers in relation to autism and developmental delay: a case-control study

Science.gov (United States)

2011-01-01

Background Polybrominated diphenyl ethers (PBDEs) are flame retardants used widely and in increasing amounts in the U.S. over the last few decades. PBDEs and their metabolites cross the placenta and studies in rodents demonstrate neurodevelopmental toxicity from prenatal exposures. PBDE exposures occur both via breastfeeding and hand-to-mouth activities in small children. Methods Participants were 100 children from the CHARGE (CHildhood Autism Risk from Genetics and the Environment) Study, a case-control epidemiologic investigation of children with autism/autism spectrum disorder, with developmental delay and from the general population. Diagnoses of autism were confirmed by the Autism Diagnostic Observation Schedule and Autism Diagnostic Inventory-Revised, and of developmental delay using the Mullen's Scales of Early Learning and the Vineland Adaptive Behavior Scales. Typically developing controls were those with no evidence of delay, autism, or autism spectrum disorder. Eleven PBDE congeners were measured by gas chromatography/mass spectrometry from serum specimens collected after children were assessed. Logistic regression was used to evaluate the association between plasma PBDEs and autism. Results Children with autism/autism spectrum disorder and developmental delay were similar to typically developing controls for all PBDE congeners, but levels were high for all three groups. Conclusions Plasma samples collected post-diagnosis in this study may not represent early life exposures due to changes in diet and introduction of new household products containing PBDEs. Studies with direct measurements of prenatal or infant exposures are needed to assess the possible causal role for these compounds in autism spectrum disorders. PMID:21205326

Spatial distribution and vertical profile of polybrominated diphenyl ethers, tetrabromobisphenol A, and decabromodiphenylethane in river sediment from an industrialized region of South China

International Nuclear Information System (INIS)

Zhang Xiulan; Luo Xiaojun; Chen Shejun; Wu Jiangping; Mai Bixian

2009-01-01

Polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and decabromodiphenylethane (DBDPE) were detected in fifteen surface sediments and two sediment cores collected from a river in one heavily industrialized region of South China. TBBPA and DBDPE were detected with concentrations ranging from 3.8 to 230 ng/g dw and from 23 to 430 ng/g dw, respectively. Σtri-hepta-BDEs and Σnona-deca-BDEs ranged from 0.7 to 7.6 ng/g dw and from 30 to 5700 ng/g dw, respectively. Σtri-hepta-BDEs showed an increasing trend whereas for Σnona-deca-BDE two sediment cores revealed a decreasing trend in more recent sediment layers which may attributed to the introduction of DBDPE. The rapid increasing trend for TBBPA and DBDPE in recent sediment layers well reflected the rising demand of these two compounds in study area. - Ubiquitous and historical contamination by PBDE, TBBPA, and DBDPE in river sediments from an industrialized region of South China

Spatial distribution and vertical profile of polybrominated diphenyl ethers, tetrabromobisphenol A, and decabromodiphenylethane in river sediment from an industrialized region of South China

Energy Technology Data Exchange (ETDEWEB)

Zhang Xiulan [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Science, Beijing 100039 (China); Luo Xiaojun, E-mail: luoxiaoj@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Shejun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wu Jiangping [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Science, Beijing 100039 (China); Mai Bixian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2009-06-15

Polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and decabromodiphenylethane (DBDPE) were detected in fifteen surface sediments and two sediment cores collected from a river in one heavily industrialized region of South China. TBBPA and DBDPE were detected with concentrations ranging from 3.8 to 230 ng/g dw and from 23 to 430 ng/g dw, respectively. SIGMAtri-hepta-BDEs and SIGMAnona-deca-BDEs ranged from 0.7 to 7.6 ng/g dw and from 30 to 5700 ng/g dw, respectively. SIGMAtri-hepta-BDEs showed an increasing trend whereas for SIGMAnona-deca-BDE two sediment cores revealed a decreasing trend in more recent sediment layers which may attributed to the introduction of DBDPE. The rapid increasing trend for TBBPA and DBDPE in recent sediment layers well reflected the rising demand of these two compounds in study area. - Ubiquitous and historical contamination by PBDE, TBBPA, and DBDPE in river sediments from an industrialized region of South China

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building.

Science.gov (United States)

Ni, Hong-Gang; Cao, Shan-Ping; Chang, Wen-Jing; Zeng, Hui

2011-07-01

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM(2.5) (Particulate Matter up to 2.5 μm in size) bounded Σ(15)PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM(10) (Particulate Matter up to 10 μm in size) bounded Σ(15)PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ(15)PBDEs via dust inhalation and ingestion for adults reached ∼ 141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. Copyright © 2010 Elsevier Ltd. All rights reserved.

Brominated flame retardants in Chinese air before and after the phase out of polybrominated diphenyl ethers

Science.gov (United States)

Li, Wen-Long; Qi, Hong; Ma, Wan-Li; Liu, Li-Yan; Zhang, Zhi; Mohammed, Mohammed O. A.; Song, Wei-Wei; Zhang, Zifeng; Li, Yi-Fan

2015-09-01

Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and novel non-BDE flame retardants (NBFRs), were analyzed in Chinese air during China's POPs Soil and Air Monitoring Program Phase I (SAMP-I) and Phase II (SAMP-II). The levels of Σ12PBDEs and Σ6NBFRs in urban sites were significantly higher than those in rural sites and background sites. The higher detection rate and concentrations of high molecular weight PBDEs and NBFRs in Phase II indicated the changing of the commercial pattern of BFRs after the phase out of PBDEs in China. Temperature was the major factor affecting the seasonal variations of molecular weight BFRs in atmosphere. A significant correlation between BFRs concentration and gross domestic product (GDP) was observed, with the GDP parameter explained 59.4% and 72.7% of the total variability for Octa-BDEs and low molecular weight NBFRs, respectively. Our findings indicated an evolving commercial usage of BFRs from SAMP-I to SAMP-II, i.e. shifting from lower molecular weight to higher molecular weight congeners in China.

Induction of Adipocyte Differentiation by Polybrominated Diphenyl Ethers (PBDEs) in 3T3-L1 Cells

Science.gov (United States)

Tung, Emily W. Y.; Boudreau, Adèle; Wade, Michael G.; Atlas, Ella

2014-01-01

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. PMID:24722056

Polybrominated diphenyl ethers in indoor air during waste TV recycling process

Energy Technology Data Exchange (ETDEWEB)

Guo, Jie [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Lin, Kuangfei; Deng, Jingjing; Fu, Xiaoxu [State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2015-02-11

Graphical abstract: - Highlights: • Air in the workshops was seriously contaminated by TV recycling activities. • PBDEs profiles and levels varied with particulate matters and different workshops. • Equilibrium between gas-particle partitioning was disrupted by recycling process. • The highest occupational exposure concentrations occurred during heating process. - Abstract: Recycling process for waste TV sets mainly consists of dismantling, printed wiring board (PWB) heating, PWB recycling, and plastic crushing in formal recycling plant. Polybrominated diphenyl ethers (PBDEs) contained in waste TV sets are released to indoor air. Air samples at 4 different workshops were collected to measure the PBDEs concentrations in both gaseous and particulate phases. The mean concentrations of ∑PBDEs in indoor air were in the range of 6780–2,280,000 pg/m{sup 3}. The highest concentration in gaseous phase (291,000 pg/m{sup 3}) was detected in the PWB heating workshop. The ∑{sub 12}PBDEs concentrations in PM{sub 2.5} and PM{sub 10} at the 4 workshops ranged in 6.8–6670 μg/g and 32.6–6790 μg/g, respectively. The gas-particle partitioning of PBDEs was disrupted as PBDEs were continuously released during the recycling processes. Occupational exposure assessment showed that only the exposure concentration of BDE-47 (0.118 μg/kg/day) through inhalation in the PWB heating workshop for workers without facemask exceeded the reference dose (0.1 μg/kg/day), posing a health hazard to workers. All the results demonstrated that recycling of TV sets was an important source of PBDEs emission, and PBDEs emission pollution was related to the composition of TV sets, interior dust, and recycling process.

Induced production of brominated aromatic compounds in the alga Ceramium tenuicorne.

Science.gov (United States)

Dahlgren, Elin; Enhus, Carolina; Lindqvist, Dennis; Eklund, Britta; Asplund, Lillemor

2015-11-01

In the Baltic Sea, high concentrations of toxic brominated aromatic compounds have been detected in all compartments of the marine food web. A growing body of evidence points towards filamentous algae as a natural producer of these chemicals. However, little is known about the effects of environmental factors and life history on algal production of brominated compounds. In this study, several congeners of methoxylated polybrominated diphenyl ethers (MeO-PBDEs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and brominated phenols (BPs) were identified in a naturally growing filamentous red algal species (Ceramium tenuicorne) in the Baltic Sea. The identified substances displayed large seasonal variations in the alga with a concentration peak in July. Production of MeO-/OH-PBDEs and BPs by C. tenuicorne was also established in isolated clonal material grown in a controlled laboratory setting. Based on three replicates, herbivory, as well as elevated levels of light and salinity in the culture medium, significantly increased the production of 2,4,6-tribromophenol (2,4,6-TBP). Investigation of differences in production between the isomorphic female, male and diploid clonal life stages of the alga grown in the laboratory revealed a significantly higher production of 2,4,6-TBP in the brackish water female gametophytes, compared to the corresponding marine gametophytes. Even higher concentrations of 2,4,6-TBP were produced by marine male gametophytes and sporophytes.

Apparatus for washing out halogens

Energy Technology Data Exchange (ETDEWEB)

Pier, M; Hahn, J; Kroenig, W

1941-03-26

An apparatus is described for washing out of halogens and the like or liquid halogen compounds from the products, which are formed on pressure hydrogenation or splitting of carbon-containing material in the presence of halogens or halogen compounds, consisting of a washing apparatus installed between the reaction vessel and the hot separator, which is inclined in relatively small space for steam regulation and contains, with the steam, arranged baffles, especially spirals.

Discovery of 1-(4-((3-(4-methylpiperazin-1-yl)propyl)amino)benzyl)-5-(trifluoromethyl)pyridin-2(1H)-one, an orally active multi-target agent for the treatment of diabetic nephropathy.

Science.gov (United States)

Chen, Jun; Peng, Zhangzhe; Lu, Miaomiao; Xiong, Xuan; Chen, Zhuo; Li, Qianbin; Cheng, Zeneng; Jiang, Dejian; Tao, Lijian; Hu, Gaoyun

2018-01-15

Oxidative stress, inflammation and fibrosis can cause irreversible damage on cell structure and function of kidney and are key pathological factors in Diabetic Nephropathy (DN). Therefore, multi-target agents are urgently need for the clinical treatment of DN. Using Pirfenidone as a lead compound and based on the previous research, two novel series (5-trifluoromethyl)-2(1H)-pyridone analogs were designed and synthesized. SAR of (5-trifluoromethyl)-2(1H)-pyridone derivatives containing nitrogen heterocyclic ring have been established for in vitro potency. In addition, compound 8, a novel agent that act on multiple targets of anti-DN with IC 50 of 90μM in NIH3T3 cell lines, t 1/2 of 4.89±1.33h in male rats and LD 50 >2000mg/kg in mice, has been advanced to preclinical studies as an oral treatment for DN. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rigid-rod polyamides and polyimides derived from 4,3 ''-diamino-2 ',6 '-diphenyl- or di(4-biphenylyl)-p-terphenyl and 4-amino-4 ''-carboxy-2 ',6 '-diphenyl-p-terphenyl

NARCIS (Netherlands)

Spiliopoulos, IK; Mikroyannidis, JA; Tsivgoulis, GM

1998-01-01

4,3 "-Diamino-2',6'-diphenyl- or di(4-biphenylyl)p-terphenyl (3a or 3b) and 4-amino-4 "-carboxy-2',6'-diphenyl-p-terphenyl (6) were synthesized through pyrylium salts and used for the preparation of rigid-rod polyamides and polyimides. The polymers were characterized by inherent viscosity, elemental

The effect of halogen hetero-atoms on the vapor pressures and thermodynamics of polycyclic aromatic compounds measured via the Knudsen effusion technique

International Nuclear Information System (INIS)

Goldfarb, Jillian L.; Suuberg, Eric M.

2008-01-01

Knowledge of vapor pressures of high molar mass organics is essential to predicting their behavior in combustion systems as well as their fate and transport within the environment. This study involved polycyclic aromatic compounds (PACs) containing halogen hetero-atoms, including bromine and chlorine. The vapor pressures of eight PACs, ranging in molar mass from (212 to 336) g . mol -1 , were measured using the isothermal Knudsen effusion technique over the temperature range of (296 to 408) K. These compounds included those with few or no data available in the literature, namely: 1,4-dibromonaphthalene, 5-bromoacenaphthene, 9-bromoanthracene, 1,5-dibromoanthracene, 9,10-dibromoanthracene, 2-chloroanthracene, 9,10-dichloroanthracene, and 1-bromopyrene. Enthalpies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. An analysis is presented on the effects of the addition of halogen hetero-atoms to pure polycyclic aromatic hydrocarbons using these data as well as available literature data. As expected, the addition of halogens onto these PACs increases their enthalpies of sublimation and decreases their vapor pressures as compared to the parent compounds

Hepatoprotective activity of petroleum ether, diethyl ether, and methanol extract of Scoparia dulcis L. against CCl4-induced acute liver injury in mice.

Science.gov (United States)

Praveen, T K; Dharmaraj, S; Bajaj, Jitendra; Dhanabal, S P; Manimaran, S; Nanjan, M J; Razdan, Rema

2009-06-01

The present study was aimed at assessing the hepatoprotective activity of 1:1:1 petroleum ether, diethyl ether, and methanol (PDM) extract of Scoparia dulcis L. against carbon tetrachloride-induced acute liver injury in mice. The PDM extract (50, 200, and 800 mg/kg, p.o.) and standard, silymarin (100 mg/kg, p.o) were tested for their antihepatotoxic activity against CCl4-induced acute liver injury in mice. The hepatoprotective activity was evaluated by measuring aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total proteins in serum, glycogen, lipid peroxides, superoxide dismutase, and glutathione reductase levels in liver homogenate and by histopathological analysis of the liver tissue. In addition, the extract was also evaluated for its in vitro antioxidant activity using 1, 1-Diphenyl-2-picrylhydrazyl scavenging assay. The extract at the dose of 800 mg/kg, p.o., significantly prevented CCl4-induced changes in the serum and liver biochemistry (P Scoparia dulcis L. possesses potential hepatoprotective activity, which may be attributed to its free radical scavenging potential, due to the terpenoid constituents.

The impact of polybrominated diphenyl ether prohibition: A case study on the atmospheric levels in China, Japan and South Korea

Science.gov (United States)

Li, Qilu; Li, Jun; Chaemfa, Chakra; Zhang, Gan; Kobara, Yuso; Nam, Jae-Jak; Jones, Kevin C.

2014-06-01

The atmosphere is an important medium which could directly reflect the changes of pollutant sources. Worldwide, the commercial products of polybrominated diphenyl ethers (PBDEs) have been officially restricted and subsequently prohibited. For the purpose of evaluating their concentration after prohibition, passive air samplers (PASs) were therefore deployed again across the East Asia during two periods in 2008 after the initial deployment 4 years ago. When compared with the data in 2004, the atmospheric concentrations of PBDEs have declined significantly. Spatially, the PBDE level in China was still the highest, with a mean value of 15.4 pg m- 3, and in Japan was the lowest (2.47 ± 1.12 pg m- 3) in the East Asia. Moreover, the relatively high concentrations were observed at sites where there are electronic or e-waste recycling industries, and this is particularly true in China, suggesting that illegally imported e-waste is still a typical source of PBDEs in this region.

5-Imino-3,4-diphenyl-1H-pyrrol-2-one

Directory of Open Access Journals (Sweden)

Evgeny Bulatov

2014-02-01

Full Text Available The title compound, C16H12N2O, exists in the crystalline state as the 5-imino-3,4-diphenyl-1H-pyrrol-2-one tautomer. The dihedral angles between the pyrrole and phenyl rings are 35.3 (2 and 55.3 (2°. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generate a graph-set motif of R22(8 via N—H...N hydrogen bonds.

An exposure study with polybrominated diphenyl ethers (PBDEs) in female European starlings (Sturnus vulgaris): Toxicokinetics and reproductive effects

International Nuclear Information System (INIS)

Steen, Evi van den; Eens, Marcel; Covaci, Adrian; Dirtu, Alin C.; Jaspers, Veerle L.B.; Neels, Hugo; Pinxten, Rianne

2009-01-01

We exposed female European starlings to a pentabromodiphenyl ether (Penta-BDE) mixture through subcutaneous implants, and examined levels and profiles of polybrominated diphenyl ethers (PBDEs) together with reproductive effects. Sum PBDE levels increased significantly in the serum of the exposed females from 218 ± 43 to 23,400 ± 2035 pg/ml. Sum PBDE concentrations in the eggs of the exposed group ranged from 130 ± 12 to 220 ± 37 ng/g wet weight (ww). The profile in serum after egg laying was very similar to that in eggs. There were no detectable levels of HO-PBDEs in both serum and eggs. Fewer females of the exposed group initiated egg laying compared to the control group, although the difference was not significant. In addition, egg weight and volume were significantly higher in the exposed group. These results suggest that, at the investigated exposure levels (150 μg sum PBDEs/bird), PBDEs may have a negative effect on reproductive performance. - Exposure to an environmentally relevant concentration of PBDEs may result in adverse reproductive effects in a terrestrial songbird species, the European starling

Polybrominated diphenyl ethers in the serum and breast milk of the resident population from production area, China.

Science.gov (United States)

Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian; Tang, Xiaoyan

2009-10-01

Polybrominated diphenyl ethers (PBDEs) have been produced in the south coast area of Laizhou Bay, Shandong Province in China, but little is known about the PBDE exposure level of residents to these compounds. We set out to assess potential health risks of PBDEs in the south coast area of the Laizhou Bay by determining the concentrations of PBDEs in serum and breast milk. We measured concentrations of eight PBDE congeners in serum and breast milk. The arithmetic means of Sigma(8)PBDE in pooled serum and breast milk were 613 ng/g lipid and 81.5 ng/g lipid, respectively. The highest concentration for Sigma(8)PBDE in all serum pools was 1830 ng/g lipid from the 41-50 year old female group. BDE-209 was the predominant congener, with the mean concentrations of 403 ng/g lipid in serum and 45.6 ng/g lipid in breast milk, respectively. BDE-209 averagely accounted for 65.8% and 54.2% of the total PBDEs, respectively. Our results suggest that high exposures to PBDEs have led to very high PBDE concentrations in serum and breast milk from the residents living in the south coast area of Laizhou Bay. High PBDE concentrations in human serum, particularly in women, pose a potential public health threat to local residents.

Contamination of phthalate esters, organochlorine pesticides and polybrominated diphenyl ethers in agricultural soils from the Yangtze River Delta of China.

Science.gov (United States)

Sun, Jianteng; Pan, Lili; Zhan, Yu; Lu, Hainan; Tsang, Daniel C W; Liu, Wenxin; Wang, Xilong; Li, Xiangdong; Zhu, Lizhong

2016-02-15

To reveal the pollution status associated with rapid urbanization and economic growth, extensive areas of agricultural soils (approximately 45,800 km(2)) in the Yangtze River Delta of China were investigated with respect to selected endocrine disruptor compounds (EDCs), including phthalate esters (PAEs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). The residues of sum of 15 PAEs, sum of 15 OCPs and sum of 13 PBDEs were in the range of 167-9370 ng/g, 1.0-3520 ng/g, and usage and recent input. Agricultural plastic film was considered to be an important source of PAEs. Discharge from furniture industry was potential major source of PBDEs in this region. The selected pollutants showed quite different spatial distributions within the studied region. It is worth noting that much higher concentrations of the EDCs were found on the borders between Shanghai and the two neighboring provinces, where agriculture and industry developed rapidly in recent years. Contaminants from both agricultural and industrial activities made this area a pollution hotspot, which should arouse more stringent regulation to safeguard the environment and food security. Copyright © 2015 Elsevier B.V. All rights reserved.

Allergic contact dermatitis due to highly reactive halogenated compounds

Energy Technology Data Exchange (ETDEWEB)

Pickering, F C; Ive, F A

1983-11-01

Ten cases of dermatitis in a fine organic chemicals plant are reported. These cases were all due to exposure to chemical compounds with reactive bromine or chlorine atoms. This type of chemical is always extremely irritant, but evidence is put forward to suggest that these cases were the result of allergic sensitization. Chemicals with reactive halogen atoms should always be handled with extreme care and patch testing should be approached with caution.

Polybrominated diphenyl ethers in fish and sediment from river polluted by electronic waste

Energy Technology Data Exchange (ETDEWEB)

Luo Qian [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Cai Zongwei [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)]. E-mail: zwcai@hkbu.edu.hk; Wong Minghung [Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)]. E-mail: mhwong@hkbu.edu.hk

2007-09-20

The present study investigated contamination of polybrominated diphenyl ethers (PBDEs) in sediment and fish samples collected from rivers in Guiyu, China where electronic waste (e-waste) is recycled and disposed. PBDE congeners with mono-to hepta-brominated and deca-brominated substitutions were detected using {sup 13}C{sub 12} isotope dilution GC/MS/MS and GC/MS methods, respectively. The total PBDE concentrations ranged from 4434 to 16088 ng/g (dry weight) in Nanyang River bank sediment, from 55 to 445 ng/g in Nanyang River bottom sediment and 51.3 to 365 ng/g in Lianjiang River bottom sediment in Guiyu compared with those from 16.1 to 21.4 ng/g in wastewater discharged from a vehicle repairing workshop in Lo Uk Tsuen in Hong Kong. No PBDE congeners were detected in bottom sediment and fish from Mai Po Marshes in Hong Kong. The mean concentrations of total PBDEs in mixed muscles of tilapia (Oreochromis spp) from Lianjiang River were 115 ng/g wet weight (ww) and from wastewater in Hong Kong were 4.1 ng/g ww. Highest mean PBDE concentration was obtained in liver (2687 ng/g ww), followed by abdomen muscle (1088 ng/g ww) of bighead carp (Aristichthys nobilis) collected from Nanyang River. A significant correlation of concentration of each PBDE congener between sediment and muscle from Guiyu was observed. The present results of total PBDEs in sediment and fish were 10 and 1000 times higher than other studies. Open burning and dumping of e-waste are the major causes of PBDE contamination.

Review on the occurrence and profiles of polybrominated diphenyl ethers in the Philippines.

Science.gov (United States)

Mackintosh, Susan A; Wallace, Joshua S; Gross, Michael S; Navarro, Denise D; Pérez-Fuentetaja, Alicia; Alaee, Mehran; Montecastro, Doris; Aga, Diana S

2015-12-01

The environmental occurrence of polybrominated diphenyl ethers (PBDEs) has been a subject of concern for the past decade because they are persistent, bioaccumulative, and toxic. These compounds have been listed as persistent organic pollutants (POPs) by the Stockholm Convention and are expected to disperse in the global environment even after their use and production. While the occurrence of PBDEs has been well characterized in environmental and biological samples from North America, Europe, and some Asian countries (i.e. China, Japan, and Korea), there is a scarcity of available data in developing Asian countries, such as the Philippines. Examination of PBDE contamination in the Philippine environment is particularly important because regulations have only recently been implemented on the production and use of PBDEs in this country. Additionally, the Philippines receives e-waste from Western countries, which is becoming a major source of organic contaminants in the tropical Asian regions. Ultimately, the Philippines may be a hot spot for contributing to on-going global PBDE pollution due to long-range atmospheric transport. This paper presents a review of the available literature on PBDEs in both environmental and biological samples collected from the Philippines. It is also intended to provide an overview on the levels and congener profiles of PBDEs in samples from the Philippines and to compare these data with other Asian countries. New data are presented on PBDE occurrence and congener profiles in fish commonly consumed by Filipinos and in particulate matter samples collected in Metro Manila, the capital of the Philippines. Both studies contribute to the available knowledge of PBDEs in the Philippines. We aim to stress the importance of future studies in countries receiving e-wastes, such as the Philippines, and suggest what future directions might be taken to enhance the available data on the presence of PBDEs in the Philippine environment. Copyright © 2015

Temporal trends of hexabromocyclododecanes (HBCDs) and polybrominated diphenyl ethers (PBDEs) and detection of two novel flame retardants in marine mammals from Hong Kong, South China.

Science.gov (United States)

Lam, James C W; Lau, Ridge K F; Murphy, Margaret B; Lam, Paul K S

2009-09-15

Concentrations of hexabromocyclododecanes (HBCDs), polybrominated diphenyl ethers (PBDEs), and three novel flame retardants, namely2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), bis-(2-ethylhexyl)-tetrabromophthalate (TBPH), and hexachlorocyclopentadienyldibromocyclooctane (HCDBCO), were determined in blubber samples of Indo-Pacific humpback dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides). The levels of HBCDs and PBDEs in cetacean samples ranged from 4.1 to 519 and 103 to 51,100 ng/g lw, respectively. A significant increasing trend of SigmaHBCDs was observed in dolphin samples from 1997 to 2007 with an estimated annual rate of 5%, whereas no significant temporal trends of SigmaPBDEs appeared over the sampling period. This pattern may be attributed to the increasing usage of HBCDs following the restriction/voluntary withdrawal of the production and use of PBDE commercial mixtures in several countries. HCDBCO was not found in the blubber samples. This is the first report of the presence of TBB and TBPH, two new flame retardants that have previously been identified in house dust from the U.S., in marine mammals; concentrations of these compounds in dolphins and porpoises ranged from the instrumental detection limit (IDL) (<0.04) to 70 and IDL (<0.04) to 3859 ng/g lw, respectively. Levels of TBPH were comparable to SigmaHBCDs in porpoise samples. The presence of these novel flame retardants in top-trophic-level marine organisms raises concern about their release into the environment and indicates the need for further monitoring of these compounds in other environmental matrices.

Organic halogen compounds and surface water pollution; Composti organoalogenati alifatici e contaminazione delle acque superficiali

Energy Technology Data Exchange (ETDEWEB)

Cocchioni, M.; Pellegrini, M. G.; Grappasonni, I.; Nacciarriti, L.; Bernacchia, G. [Camerino, Univ. (Italy). Dipt. di Scienze Igienistiche e Sanitarie-Ambientali

1997-03-01

A brief review of the effects of halogenated organic compounds on the fluvial ecosystem is followed by results from a detailed monitoring of these substances in all the Marches Region rivers. The results show generally modest concentrations, except for sporadic peaks for chloroform. Sites revealing significant concentrations of halogenated organic compounds also manifested a worsening of the biological quality of the waters with lessening of E.B.I. Attention is drawn to the negative effects of indiscriminate chlorination of purification plant outputs, as this practice often fails to resolve infective problems and in itself adds toxicity to the watercourse.

Children's exposure to polybrominated diphenyl ethers.

NARCIS (Netherlands)

Zuurbier, M.; Leijs, M.; Schoeters, G.; Tusscher, G. Ten; Koppe, J.G.

2006-01-01

Background: Polybrominated biphenyl ethers (PBDEs), a class of brominated flame retardants, are frequently used in consumer products. PBDEs levels in environmental and human samples have increased in recent decades. Children are exposed to PBDEs through diet, mainly through fish, meat and milk.

A Survey of Electron Impact Cross-Sections for Halogens and Halogen Compounds of Interest to Plasma Processing

Science.gov (United States)

Sharma, S. P.; Rao, M. V. V. S.; Arnold, James O. (Technical Monitor)

1998-01-01

Published electron impact cross section data on halogens Cl2, F2, and halogen containing compounds such as Cx Fy, HCl, Cx Cly Fz are reviewed and critically evaluated based on the information provided by various researchers. The present work reports data on electron impact excitation, ionization, dissociation, electron attachment, electron detachment, and photo detachment. Elastic scattering cross sections and data on bulk properties such as diffusion coefficients in various background gases are also evaluated. Since some of the cross sectional data is derived from indirect measurements such as drift velocity, care has been taken to reconcile the differences among the reported data with due attention to the measurement technique. In conclusion, the processes with no or very limited amount of data and questionable set of data are identified and recommendation for further research direction is made.

Disruption of thyroid hormone binding to sea bream recombinant transthyretin by ioxinyl and polybrominated diphenyl ethers.

Science.gov (United States)

Morgado, Isabel; Hamers, Timo; Van der Ven, Leo; Power, D M

2007-08-01

A number of chemicals released into the environment share structural similarity to the thyroid hormones (THs), thyroxine (T(4)) and triiodothyronine (T(3)) and it is thought that they may interfere with the thyroid axis and behave as endocrine disruptors (EDs). One of the ways by which such environmental contaminants may disrupt the TH axis is by binding to TH transporter proteins. Transthyretin (TTR) is one of the thyroid hormone binding proteins responsible for TH transport in the blood. TTR forms a stable tetramer that binds both T(4) and T(3) and in fish it is principally synthesized in the liver but is also produced by the brain and intestine. In the present study, we investigate the ability of some chemicals arising from pharmaceutical, industrial or agricultural production and classified as EDs, to compete with [I(125)]-T(3) for sea bream recombinant TTR (sbrTTR). Ioxinyl, a common herbicide and several polybrominated diphenyl ethers were strong inhibitors of [I(125)]-T(3) binding to TTR and some showed even greater affinity than the natural ligand T(3). The TTR competitive binding assay developed offers a quick and effective tool for preliminary risk assessment of chemicals which may disrupt the thyroid axis in teleost fish inhabiting vulnerable aquatic environments.

Quantitative analysis of 39 polybrominated diphenyl ethers by isotope dilution GC/low-resolution MS.

Science.gov (United States)

Ackerman, Luke K; Wilson, Glenn R; Simonich, Staci L

2005-04-01

A GC/low-resolution MS method for the quantitative isotope dilution analysis of 39 mono- to heptabrominated diphenyl ethers was developed. The effects of two different ionization sources, electron impact (EI) and electron capture negative ionization (ECNI), and the effects of their parameters on production of high-mass fragment ions [M - xH - yBr](-) specific to PBDEs were investigated. Electron energy, emission current, source temperature, ECNI system pressure, and choice of ECNI reagent gases were optimized. Previously unidentified enhancement of PBDE high-mass fragment ion [M - xH - yBr](-) abundance was achieved. Electron energy had the largest impact on PBDE high-mass fragment ion abundance for both the ECNI and EI sources. By monitoring high-mass fragment ions of PBDEs under optimized ECNI source conditions, quantitative isotope dilution analysis of 39 PBDEs was conducted using nine (13)C(12) labeled PBDEs on a low-resolution MS with low picogram to femtogram instrument detection limits.

Risk assessments of polybrominated diphenyl ethers (PBDEs) during sludge application in China

Science.gov (United States)

Qian, Jun

2018-02-01

Due to increasingly less space in municipal environment, waste management has become an urgent issue worldwide. As one of common municipal waste, sewage sludge from wastewater treatment plants (WWTPs) contains abundant nutrients, some of which can be quite essential for plant growth. In consideration of nutrient recycling and energy saving, sludge application has been frequently promoted in many countries across the world. However, even after several sludge stabilization procedures, sewage sludge may still contain a large variety of toxic pollutants, especially some emerging organic contaminants (EOCs). Applied in various household products and plastic industries as additives, polybrominated diphenyl ethers (PBDEs) have been constantly detected in sewage sludge samples from several cities in China since 2005, as well as some biosolid samples after sludge stabilization processes, suggesting their strong persistence and wide occurrence. During sludge application onto farmland soils, PBDEs may desorb from sludge particles and get attached by soil organic matter (SOM), followed by plant root uptake and translocation to aboveground tissues. In this study, data about current pollution of PBDEs in sewage sludge samples from China was reviewed, and the potential risks during sludge application was comprehensively assessed.

Temporal variability of polybrominated diphenyl ether (PBDE) serum concentrations over one year.

Science.gov (United States)

Makey, Colleen M; McClean, Michael D; Sjödin, Andreas; Weinberg, Janice; Carignan, Courtney C; Webster, Thomas F

2014-12-16

Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals used in consumer products. They are common contaminants in human serum and associated with adverse health effects. Our objectives were to characterize PBDE serum concentrations in a New England cohort and assess temporal variability of this exposure biomarker over a one-year period. We collected three repeated measurements at six-month intervals from 52 office workers from the greater Boston (MA, United States) area from 2010 to 2011. The intraclass correlation coefficient for BDEs 28, 47, 99, 100, and 153 ranged from 0.87 to 0.99, indicating that a single serum measurement can reliably estimate exposure over a one-year period. This was true for both lipid adjusted and nonlipid adjusted concentrations. The kappa statistics, quantifying the level of agreement of categorical exposure classification, based on medians, tertiles, or quartiles ranged from 0.67 to 0.90. Some congeners showed nonsignificant increases from sampling round 1 (winter) to round 2 (summer) and significant decreases from round 2 to round 3 (winter). This study highlights the high reliability of a single serum PBDE measurement for use in human epidemiologic studies.

1,2'-Bis(4-aminophenoxy)benzene based designed fluoro-poly(ether-imide)/MMT clay nanocomposites: Synthesis and properties for high performance applications

International Nuclear Information System (INIS)

Vora, Rohitkumar H.; Vora, Mayur

2006-01-01

In an effort to develop structure-property understanding of fluoro-polymer/inorganic clay nanocomposite (i.e., Ceramer) technology, two series of fluoro-poly(ether amic acid) (6F-PEAA)/organosoluble Montmorillonite (MMT) clay nanocomposite formulations containing varying percentage of diamine modified (ion-exchanged) organosoluble-MMT clay were prepared from the partially fluorinated fluoro poly(ether-amic acid)s (6F-PEAA) synthesized by reacting on 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and di-ether-containing diamines, such as 1,2'-bis(4-aminophenoxy) benzene (o-BAPOB) and 4,4'-bis(4-aminophenoxy) diphenyl sulfone (p-SED), respectively. Self supporting films were cast from these formulations and cured at elevated temperatures. XRD data, indirectly confirmed the exfoliation of organosoluble-MMT clay at molecular level in the nanocomposite. The solubility, chemical resistance, morphology, thermo-oxidative stability, thermal degradation kinetics, mechanical behavior, and moisture absorption of these [(6F-PEI)/MMT clay] nanocomposite films were systematically studied

Synthesis of N-(4-bromo-2-trifluoromethylphenyl)-1-(2-fluorophenyl)-O,O-dialkyl-alpha-aminophosphonates under ultrasonic irradiation.

Science.gov (United States)

Song, Bao-An; Zhang, Guo-Ping; Yang, Song; Hu, De-Yu; Jin, Lin-Hong

2006-02-01

Boron trifluoride diethyl etherate catalyzes the Mannich-type reaction of 2-trifluoromethyl-4-bromoaniline and O,O-dialkylphosphite with 2-fluorobenzoaldehyde under ultrasonic irradiation to synthesize the corresponding product alpha-aminophosphonate. The advantages of the procedure include short reaction period, high yield and simple working up. Their structures were clearly established by IR, (1)H NMR, (13)C NMR and elemental analysis. The bioassay tests showed that the title compounds exhibit moderate antitumor activity in vitro by MTT method.

Energetic effects of ether and ketone functional groups in 9,10-dihydroanthracene compound

International Nuclear Information System (INIS)

Freitas, Vera L.S.; Gomes, Jose R.B.; Ribeiro da Silva, Maria D.M.C.

2010-01-01

The energetic effects caused by replacing one of the methylene groups in the 9,10-dihydroanthracene by ether or ketone functional groups yielding xanthene and anthrone species, respectively, were determined from direct comparison of the standard (p o = 0.1 MPa) molar enthalpies of formation in the gaseous phase, at T = 298.15 K, of these compounds. The experimental static-bomb combustion calorimetry and Calvet microcalorimetry and the computational G3(MP2)//B3LYP method were used to get the standard molar gas-phase enthalpies of formation of xanthene, (41.8 ± 3.5) kJ . mol -1 , and anthrone, (31.4 ± 3.2) kJ . mol -1 . The enthalpic increments for the substitution of methylene by ether and ketone in the parent polycyclic compound (9,10-dihydroanthracene) are -(117.9 ± 5.5) kJ . mol -1 and -(128.3 ± 5.4) kJ . mol -1 , respectively.

Hydrodebromination of decabromodiphenyl ether (BDE-209) in cooking experiments with salmon fillet.

Science.gov (United States)

Bendig, Paul; Blumenstein, Marina; Hägele, Florian; Vetter, Walter

2012-08-29

Polybrominated diphenyl ethers (PBDEs) are environmental contaminants regularly detected in biota and food. Seafood has been identified as the major dietary source for human uptake. Fish is predominantly consumed after cooking, and this process may alter the actual human intake of contaminants. This study thus aimed to investigate the fate of PBDEs in this cooking process. Heating of fish fortified with 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) at typical cooking conditions (200 °C, in plant oil) resulted in a decrease of its concentration in favor of the formation of lower brominated congeners. After 15 min, ∼25% of BDE-209 was transformed into nona- to octabrominated congeners. The major transformation route was BDE-209 → BDE-206 → BDE-196 and BDE-199. Low amounts of heptabrominated congeners as well as one hexabromodibenzofuran and a heptabromodibenzofuran isomer were also detected. However, penta- and tetrabrominated diphenyl ethers were not observed, and heating of BDE-47 did not produce new transformation products.

Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy).

Science.gov (United States)

Binelli, A; Guzzella, L; Roscioli, C

2008-06-01

Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with summation operatorPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447ngg(-1) lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47>-99>-100>-209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide.

Effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds using a modified QSAR model.

Science.gov (United States)

Lim, Seung Joo; Fox, Peter

2014-02-01

The effects of halogenated aromatics/aliphatics and nitrogen(N)-heterocyclic aromatics on estimating the persistence of future pharmaceutical compounds were investigated using a modified half life equation. The potential future pharmaceutical compounds investigated were approximately 2000 pharmaceutical drugs currently undergoing the United States Food and Drug Administration (US FDA) testing. EPI Suite (BIOWIN) model estimates the fates of compounds based on the biodegradability under aerobic conditions. While BIOWIN considered the biodegradability of a compound only, the half life equation used in this study was modified by biodegradability, sorption and cometabolic oxidation. It was possible that the potential future pharmaceutical compounds were more accurately estimated using the modified half life equation. The modified half life equation considered sorption and cometabolic oxidation of halogenated aromatic/aliphatics and nitrogen(N)-heterocyclic aromatics in the sub-surface, while EPI Suite (BIOWIN) did not. Halogenated aliphatics in chemicals were more persistent than halogenated aromatics in the sub-surface. In addition, in the sub-surface environment, the fates of organic chemicals were much more affected by halogenation in chemicals than by nitrogen(N)-heterocyclic aromatics. © 2013.

Polybrominated diphenyl ethers and polychlorinated biphenyls in human adipose tissue from New York.

Science.gov (United States)

Johnson-Restrepo, Boris; Kannan, Kurunthachalam; Rapaport, David P; Rodan, Bruce D

2005-07-15

Human adipose tissue samples (n=52) collected in New York City during 2003-2004 were analyzed for the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). Concentrations of PBDEs in adipose tissues ranged from 17 to 9630 ng/g, lipid wt (median: 77; mean: 399 ng/g, lipid wt; sum all di- through hexaBDE congeners). Average PBDE concentrations in human adipose tissues from New York City were 10- to 100-times greater than those reported for European countries. A concentration of 9630 ng/g, lipid wt, found in a sample of adipose tissue, is one of the highest concentrations reported to date. PBDE 47 (2,2',4,4'-tetraBDE) was the major congener detected in human tissues, followed by PBDE congeners #99 (2,2',4,4',5-penta BDE), 100 (2,2',4,4',6-pentaBDE), and 153 (2,2',4,4',5,5'-hexaBDE). A few individuals contained PBDE 153 as the predominant congener in total PBDE concentrations, suggesting alternative exposure sources, possibly occupational. Principal component analysis of PBDE congener composition in human adipose tissues revealed the presence of five clusters, each characterized by varying composition. No significant difference was found in the concentrations of PBDEs between gender. Concentrations of PBDEs were, on average, similar to those for PCBs in human adipose tissues, and substantially higher when PBDE outliers were retained. PBDE and PCB concentrations were not correlated. PBDE concentrations did not increase with increasing age of the subjects, whereas concentrations of PCBs increased with increasing age in males but not in females in this study. These results suggest differences between PBDEs and PCBs in their sources or time course of exposure and disposition. The presence of comparable or greater concentrations of PBDEs, relative to PCBs, highlights the importance of recentvoluntary and regulatory effortsto cease production of commercial penta- and octa-BDE in North America, although these efforts do not address

[Atmospheric Polybrominated Diphenyl Ethers in Eight Cities of China: Pollution Characteristics and Human Exposure].

Science.gov (United States)

Lin, Hai-tao; Li, Qi-lu; Zhang, Gan; Li, Jun

2016-01-15

The gas and particle samples of eight cities were collected by high flow active air sampler in the Eastern and Western China and eight congeners of polybrominated diphenyl ethers were analyzed. The results showed that the concentration of BDE-28 (tri-BDE) in the gas-phase (three bromide components) was the highest, which was different from previous studies where BDE-99 and-47 were the predominant homologues in the gas-phase while the concentration of BDE-209 [(25.4 ± 124) pg · m⁻³] in particle-phase was the highest. The atmospheric concentrations of PBDEs in Beijing and Guangzhou were relatively higher, especially the BDE-209 concentration in particle phases of Guangzhou was two orders higher than those of other cities. However, the atmospheric concentrations of PBDEs declined significantly when compared with the data from previous studies. Meanwhile, the results indicated that the gas-phase concentrations decreased slowly and the particle-phase concentrations decreased rapidly. Combined with the results of correlation analysis, this phenomenon might be ascribed to the ceased commercial production of penta- and octa-BDE, the light degradation of high bromide components and reduced concentrations of atmospheric particles in urban area. Inhalation exposure for infants was about 2-3 times higher than that of adults. This reflected that the potential health risk of atmospheric PBDEs in city for residents, especially infants and young children, should not be ignored.

Polybrominated diphenyl ethers (PBDEs) and organochlorines in melon-headed whales, Peponocephala electra, mass stranded along the Japanese coasts: Maternal transfer and temporal trend

International Nuclear Information System (INIS)

Kajiwara, Natsuko; Kamikawa, Satoko; Amano, Masao; Hayano, Azusa; Yamada, Tadasu K.; Miyazaki, Nobuyuki; Tanabe, Shinsuke

2008-01-01

Polybrominated diphenyl ethers (PBDEs) and organochlorine compounds (OCs) were determined in the blubber of 55 melon-headed whales (Peponocephala electra) mass stranded along the Japanese coasts since 1982. DDTs and PCBs were predominant in all the specimens investigated. In whales that died during the latest event in 2006, concentrations of PBDEs (190-510 ng/g lipid wt) were approximately two orders of magnitude lower than DDTs and PCBs, but comparable with HCHs and HCB. Maternal transfer of PBDEs to offspring through the whole reproductive process was estimated to be 85% of the mother's body burden, while that occurring during gestation was much lower (2.6-3.5%). Concentrations of PCBs, DDTs, and HCB were lower in melon-headed whales stranded after the year 2000 than those stranded in 1982, whereas PBDE and CHL levels showed a temporal increase during the past 20 years, suggesting that the peak of their usage and contamination occurred after the year 1982. - PBDE levels in melon-headed whales increased during the past two decades

Polybrominated diphenyl ethers (PBDEs) and organochlorines in melon-headed whales, Peponocephala electra, mass stranded along the Japanese coasts: Maternal transfer and temporal trend

Energy Technology Data Exchange (ETDEWEB)

Kajiwara, Natsuko; Kamikawa, Satoko [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Amano, Masao [Department of Animal Sciences, Teikyo University of Science and Technology, 2525 Yatsusawa, Uenohara, Yamanashi 409-0193 (Japan); Hayano, Azusa [Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan); Yamada, Tadasu K. [National Museum of Nature and Science, 3-23-1 Hyakunin-cho, Shinjuku-ku, Tokyo 169-0073 (Japan); Miyazaki, Nobuyuki [Center for International Cooperation, Ocean Research Institute, University of Tokyo, Minamidai 1-15-1, Nakano-ku, Tokyo 164-8639 (Japan); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)], E-mail: shinsuke@agr.ehime-u.ac.jp

2008-11-15

Polybrominated diphenyl ethers (PBDEs) and organochlorine compounds (OCs) were determined in the blubber of 55 melon-headed whales (Peponocephala electra) mass stranded along the Japanese coasts since 1982. DDTs and PCBs were predominant in all the specimens investigated. In whales that died during the latest event in 2006, concentrations of PBDEs (190-510 ng/g lipid wt) were approximately two orders of magnitude lower than DDTs and PCBs, but comparable with HCHs and HCB. Maternal transfer of PBDEs to offspring through the whole reproductive process was estimated to be 85% of the mother's body burden, while that occurring during gestation was much lower (2.6-3.5%). Concentrations of PCBs, DDTs, and HCB were lower in melon-headed whales stranded after the year 2000 than those stranded in 1982, whereas PBDE and CHL levels showed a temporal increase during the past 20 years, suggesting that the peak of their usage and contamination occurred after the year 1982. - PBDE levels in melon-headed whales increased during the past two decades.

Polybrominated diphenyl ethers: human tissue levels and toxicology.

Science.gov (United States)

Gill, Udai; Chu, Ih; Ryan, John J; Feeley, Mark

2004-01-01

PBDEs are being released to the environment in wastes from their production facilities, degradation, or leaching and volatilization from products that contain PBDEs during the product's useful life. Brominated diphenyl ether congeners BDE-47, -99, and -153 are ubiquitous in the environment and are regarded as the most dominant congeners present in wildlife and humans. The tetra- to hexa-BDE are most likely the congeners to which humans are exposed through food consumption. Knowledge of PBDE uptake, metabolism, elimination, and enzyme induction is restricted largely to rodents (rats and mice) in vitro and in vivo. Feeding studies have shown that excretion of higher brominated BDEs is much greater than lower brominated BDEs. Penta-BDE is more toxic than octa- and deca-BDE following oral administration (oral LD50 in rats, 0.5-5 g/kg). In rodents, repeated exposure to PBDEs results in thyroid hormone disruption, developmental neurotoxicity, some changes of fetal development, and hepatotoxic effects. The observed chronic NOELs depend upon the technical mixture type (i.e., deca-, octa-, or penta- and their congener composition), animal species, and study protocol. Values range from 0.6 to 100 mg/kg in rats and from I to 100 mg/kg in mice. PBDEs are neither mutagenic nor genotoxic. Immunotoxicity in mice is observed following exposure to BDE-47 at 18 mg/kg/d, where splenocyte number decreased. Mice exposed neonatally to a single oral dose of BDE-47(10.5 mg/kg) or BDE-99 (12 mg/kg) on Pnd10 (period of rapid brain growth and development) show permanent impairment of spontaneous motor behavior when reaching adulthood. BDE-99 also induced adverse effects on learning and memory functions of mice. The estimated daily intake based on food consumption for PBDEs ranges from 44 to 51 ng/d, with fish contributing almost one-half. The BDE-99 body burden from a human milk survey can be estimated at 0.64 microg/kg, well below the experimental body burden of 0.4 mg/kg BDE-99 associated

Coupling of biologically active steroids to conjugating arms through ether linkages for use in immunochemistry.

Science.gov (United States)

Kohl, Michel J; Lejeune, Robert G

2002-01-01

Conjugation of haptens through ether linkages avoids leakage problems in immunoassays, but this procedure is not easily applied to most steroids that bear low reacting hydroxyls. A new technique allowing the ether coupling of biologically active steroids with conjugating arms in mild conditions compatible with thermosensitive protecting groups is presented. In the first step, the solvent (an aromatic hydrocarbon) was dehydrated by azeotropic distillation in a soxhlet apparatus using a cartridge filled with 0.3 nm and 0.4 nm molecular sieves. In this protected medium, a thallium steroid alkoxide was completely formed by reaction of the steroid with thallium ethoxide and by the continuous elimination of ethanol. The halogenated chain was then introduced into the same medium and reacted in the absence of moisture to give the ether. 17beta-Hydroxy and 11alpha-hydroxy derivatives were involved in this reaction. The coupling was effective for all of the compounds tested after 2-36 h of reaction time and at temperatures between 80 and 140 degrees C. The conjugates were at least 95% pure, and yields ranged from 15 to 95%.

Hydroxylated polybrominated diphenyl ethers exhibit different activities on thyroid hormone receptors depending on their degree of bromination.

Science.gov (United States)

Ren, Xiao-Min; Guo, Liang-Hong; Gao, Yu; Zhang, Bin-Tian; Wan, Bin

2013-05-01

Polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone (TH) functions in experimental animals, and one of the proposed disruption mechanisms is direct binding of hydroxylated PBDE (OH-PBDE) to TH receptors (TRs). However, previous data on TH receptor binding and TH activity of OH-PBDEs were very limited and sometimes inconsistent. In the present paper, we examined the binding potency of ten OH-PBDEs with different degrees of bromination to TR using a fluorescence competitive binding assay. The results showed that the ten OH-PBDEs bound to TR with potency that correlated to their bromination level. We further examined their effect on TR using a coactivator binding assay and GH3 cell proliferation assay. Different TR activities of OH-PBDEs were observed depending on their degree of bromination. Four low-brominated OH-PBDEs (2'-OH-BDE-28, 3'-OH-BDE-28, 5-OH-BDE-47, 6-OH-BDE-47) were found to be TR agonists, which recruited the coactivator peptide and enhanced GH3 cell proliferation. However, three high-brominated OH-PBDEs (3-OH-BDE-100, 3'-OH-BDE-154, 4-OH-BDE-188) were tested to be antagonists. Molecular docking was employed to simulate the interactions of OH-PBDEs with TR and identify the structural determinants for TR binding and activity. According to the docking results, low-brominated OH-PBDEs, which are weak binders but TR agonists, bind with TR at the inner side of its binding pocket, whereas high-brominated compounds, which are potent binders but TR antagonists, reside at the outer region. These results indicate that OH-PBDEs have different activities on TR (agonistic or antagonistic), possibly due to their different binding geometries with the receptor. Copyright © 2013 Elsevier Inc. All rights reserved.

Temporal Trends of Hexabromocyclododecane, Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls in Ringed Seals from East Greenland

DEFF Research Database (Denmark)

Vorkamp, Katrin; Riget, Frank Farsø; Bossi, Rossana

2011-01-01

also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding......Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. R-HBCD was the only diastereoisomer consistently above levels of quantification and showed...... on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which...

Synthesis, Fungicidal Activity and Mode of Action of 4-Phenyl-6-trifluoromethyl-2-aminopyrimidines against Botrytis cinerea

Directory of Open Access Journals (Sweden)

Chunhui Liu

2016-06-01

Full Text Available Anilinopyrimidines are the main chemical agents for management of Botrytis cinerea. However, the drug resistance in fungi against this kind of compounds is very serious. To explore new potential fungicides against B. cinerea, a series of 4-phenyl-6-trifluoromethyl-2-amino-pyrimidine compounds (compounds III-1 to III-22 were synthesized, and their structures were confirmed by 1H-NMR, IR and MS. Most of these compounds possessed excellent fungicidal activity. The compounds III-3 and III-13 showed higher fungicidal activity than the positive control pyrimethanil on fructose gelatin agar (FGA, and compound III-3 on potato dextrose agar (PDA indicated high activity compared to the positive control cyprodinil. In vivo greenhouse results indicated that the activity of compounds III-3, III-8, and III-11 was significantly higher than that of the fungicide pyrimethanil. Scanning electron micrography (SEM and transmission electron micrography (TEM were applied to illustrate the mechanism of title compounds against B. cinerea. The title compounds, especially those containing a fluorine atom at the ortho-position on the benzene ring, could maintain the antifungal activity against B. cinerea, but their mechanism of action is different from that of cyprodinil. The present study lays a good foundation for us to find more efficient reagents against B. cinerea.

Polybrominated diphenyl ethers, polychlorinated dibenzo-dioxins, -furans, and -biphenyls in three species of Antarctic penguins.

Science.gov (United States)

Corsolini, Simonetta; Borghesi, Nicoletta; Schiamone, Alessandra; Focardi, Silvano

2007-09-01

Fish-eating seabirds are recognized to be at risk of accumulating toxic contaminants due to their high position in the trophic web and to their low ability to metabolize xenobiotic compounds. Penguins are widely distributed in Antarctica and represent an important fraction of the Antarctic biomass. They feed mainly on krill and, depending on krill availability, also on fish. It has been reported that predators may be a sink for volatile and toxic chemicals and this may pose a serious environmental problem. Polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-dioxins (PCDDs), -furans (PCDFs), and -biphenyls (PCBs), including non-ortho congeners, hexachlorobenzene (HCB) and p,p'-DDE, were quantified in three species of Antarctic Pygoscelids in order to evaluate their accumulation patterns. The potential toxicity of twenty-two dioxin-like congeners was assessed and expressed as 2,3,7,8-tetraCDD equivalents (TEQs). Differences between males and females were investigated. Blood samples of the Adélie penguin Pygoscelis adeliae, Chinstrap penguin Pygoscelis antarctica and Gentoo penguin Pygoscelis papua were collected at Admiralty Bay, King George Is (62 degrees 10'39" S, 58 degrees 26'46" W) in February 2004. Halogenated hydrocarbons were identified and quantified using gas chromatography coupled with gas chromatography mass spectrometry analyses. Results are expressed on a wet weight basis. HCB, p,p'-DDE and sigmaPCBs were higher in Adélie penguins (6.7 +/- 6.1, 8.2 +/- 3.3 and 9.8 +/- 3.8 ng/g, respectively) than in Chinstrap and Gentoo penguins, both of which showed values in the same order of magnitude, but approximately 40% lower than Adélie penguins. Hexa-CBs ranged 35-45% of the residue. Low-chlorinated PCBs (nos. 70+76+95+ 56+60+101) accounted for 40-60% in the three species. PCB101 made up 15% of the residue in Adélie penguins. PBDEs were 291 +/- 477, 107 +/- 104 and 116 +/- 108 pg/g in Adélie, Chinstrap and Gentoo penguins, respectively; the

Effect of polybrominated diphenyl ether (PBDE) treatment on the composition and function of the bacterial community in the sponge Haliclona cymaeformis.

KAUST Repository

Tian, Ren-Mao

2014-01-01

Marine sponges play important roles in benthic environments and are sensitive to environmental stresses. Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants since the 1970s and are cytotoxic and genotoxic to organisms. In the present study, we studied the short-period effect of PBDE-47 (2,2\\',4,4\\'-tetrabromodiphenyl ether) treatment on the community structure and functional gene composition of the bacterial community inhabiting the marine sponge Haliclona cymaeformis. Our results showed that the bacterial community shifted from an autotrophic bacteria-dominated community to a heterotrophic bacteria-dominated community in response to PBDE-47 in a time- and concentration-dependent manner. A potentially symbiotic sulfur-oxidizing bacterium (SOB) was dominant (>80% in abundance) in the untreated sponge. However, exposure to a high concentration (1 μg/L) of PBDE-47 caused a substantial decrease in the potential symbiont and an enrichment of heterotrophic bacteria like Clostridium. A metagenomic analysis showed a selective effect of the high concentration treatment on the functional gene composition of the enriched heterotrophic bacteria, revealing an enrichment for the functions responsible for DNA repair, multidrug efflux pumping, and bacterial chemotaxis and motility. This study demonstrated that PBDE-47 induced a shift in the composition of the community and functional genes in the sponge-associated bacterial community, revealing the selective effect of PBDE-47 treatment on the functions of the bacterial community in the microenvironment of the sponge.

Occurrence of polybrominated diphenyl ethers (PBDEs) in foodstuffs in Italy and implications for human exposure.

Science.gov (United States)

Martellini, Tania; Diletti, Gianfranco; Scortichini, Giampiero; Lolini, Meri; Lanciotti, Eudes; Katsoyiannis, Athanasios; Cincinelli, Alessandra

2016-03-01

Polybrominated diphenyl ethers (PBDEs) were determined in various foodstuffs in Italy and the dietary intake was estimated. PBDEs were detected in all analysed samples at concentrations that spanned over five orders of magnitude. The most abundant congeners were the BDE-209, followed by BDE-47 and BDE-99. Fish oil and milk samples showed the highest PBDE concentrations among all samples. The daily dietary intake values were found to be in good agreement or higher to literature values, impacted mainly from the contribution of the analysed dairy products. The cancer risk values estimated for BDE-209 indicated that this specific risk associated with the studied foodstuffs is limited. Italy is one of the world-leading countries in the production of furniture and clothes and has extremely developed medium enterprise industrial sector, where PBDEs were historically used suggesting that their occurrence may be linked to these activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Palladium-Catalyzed Reductive Insertion of Alcohols into Aryl Ether Bonds

Energy Technology Data Exchange (ETDEWEB)

Wang, Meng [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Gutiérrez, Oliver Y. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Camaioni, Donald M. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Lercher, Johannes A. [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Department of Chemistry and Catalysis Research Institute, TU München, Lichtenbergstrasse 4 85748 Garching Germany

2018-03-06

Pd/C catalyzes C-O bond cleavage of aryl ethers (diphenyl ether and cyclohexyl phenyl ether) by methanol in H2. The aromatic C-O bond is cleaved by reductive methanolysis, which is initiated by Pd-catalyzed partial hydrogenation of one phenyl ring to form an enol ether. The enol ether reacts rapidly with methanol to form a ketal, which generates methoxycyclohexene by eliminating phenol or an alkanol. Subsequent hydrogenation leads to methoxycyclohexane.

Quantitative Prediction of Solvation Free Energy in Octanol of Organic Compounds

Directory of Open Access Journals (Sweden)

Eduardo J. Delgado

2009-03-01

Full Text Available The free energy of solvation, ΔGS0 , in octanol of organic compunds is quantitatively predicted from the molecular structure. The model, involving only three molecular descriptors, is obtained by multiple linear regression analysis from a data set of 147 compounds containing diverse organic functions, namely, halogenated and non-halogenated alkanes, alkenes, alkynes, aromatics, alcohols, aldehydes, ketones, amines, ethers and esters; covering a ΔGS0 range from about –50 to 0 kJ·mol-1. The model predicts the free energy of solvation with a squared correlation coefficient of 0.93 and a standard deviation, 2.4 kJ·mol-1, just marginally larger than the generally accepted value of experimental uncertainty. The involved molecular descriptors have definite physical meaning corresponding to the different intermolecular interactions occurring in the bulk liquid phase. The model is validated with an external set of 36 compounds not included in the training set.

Measurement of the flame retardants polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) in house dust

Energy Technology Data Exchange (ETDEWEB)

Stapleton, H.; Dodder, N.; Schantz, M.; Wise, S. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

2004-09-15

Current monitoring of polybrominated diphenyl ethers (PBDEs) has shown that concentrations are increasing in the environment very rapidly with doubling times as short as three to five years. North America consumes a large percentage of the global market demand for PBDEs, and as a result, concentrations of PBDEs in human milk and serum are an order of magnitude higher in women from North America relative to Europe. Within sampled populations, PBDE levels in human serum have been shown to range over an order of magnitude, and high levels cannot always be attributed to occupational exposure, age or diet. One source that may be responsible for these observations is exposure in the home. These compounds are liberally applied to many common household items such as furniture, mattresses, computers and TVs to retard or hinder the outbreak of fire. Over time, these flame retardants may leach out into the home environment, where they may be inhaled or ingested, resulting in elevated levels in human serum. Very few studies have examined PBDE levels within the home and only one study has measured the concentrations of two PBDE congeners in house dust. The present study was undertaken to measure a suite PBDE congeners in house dust from a variety of homes and to assess the contribution of the three commercial PBDE mixtures (penta-, octa- and decaBDE) to the house dust composition. In addition, we also measured the concentrations of hexabromocyclododecane (HBCDD), another flame retardant. Correlations with properties of the houses such as year of construction, square footage, carpeting coverage and number of computers in the house were also examined for any positive influences.

Is halogen content the most important factor in the removal of halogenated trace organics by MBR treatment?

Science.gov (United States)

Hai, Faisal I; Tadkaew, Nichanan; McDonald, James A; Khan, Stuart J; Nghiem, Long D

2011-05-01

This study investigated the relationship between physicochemical properties (namely halogen content and hydrophobicity) of halogenated trace organics and their removal efficiencies by a laboratory scale membrane bioreactor (MBR) under stable operating conditions. The reported results demonstrated a combined effect of halogen content and hydrophobicity on the removal. Compounds with high halogen content (>0.3) were well removed (>85%) when they possessed high hydrophobicity (Log D>3.2), while those with lower Log D values were also well removed if they had low halogen content (BIOWIN index (which is based on only biodegradation) or a more specific index such as the halogen content (which captures a chemical aspect) appeared insufficient to predict the removal efficiency of halogenated compounds in MBR. Experimental data confirmed that the ratio of halogen content and Log D, which incorporates two important physico-chemical properties, is comparatively more suitable. Copyright © 2011 Elsevier Ltd. All rights reserved.

Surface retention and photochemical reactivity of the diphenylether herbicide oxyfluorfen.

Science.gov (United States)

Scrano, Laura; Bufo, Sabino A; Cataldi, Tommaso R I; Albanis, Triantafyllos A

2004-01-01

The photochemical behavior of oxyfluorfen [2-chloro-1-(3-etoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene] on two Greek soils was investigated. Soils were sampled from Nea Malgara and Preveza regions, characterized by a different organic matter content. Soils were spiked with the diphenyl-ether herbicide and irradiation experiments were performed either in the laboratory with a solar simulator (xenon lamp) or outside, under natural sunlight irradiation; other soil samples were kept in the dark to control the retention reaction. Kinetic parameters of both retention and photochemical reactions were calculated using zero-, first- and second- (Langmuir-Hinshelwood) order equations, and best fit was checked through statistical analysis. The soil behaviors were qualitatively similar but quantitatively different, with the soil sampled from the Nea Malgara region much more sorbent as compared with Preveza soil. All studied reactions followed second-order kinetics and photochemical reactions were influenced by retaining capability of the soils. The contributions of the photochemical processes to the global dissipation rates were also calculated. Two main metabolites were identified as 2-chloro-1-(3-ethoxy-4-hydroxyphenoxy)-4-(trifluoromethyl)benzene and 2-chloro-1- (3-hydroxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene.

Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China.

Science.gov (United States)

Yu, Zhiqiang; Liao, Ru'e; Li, Huiru; Mo, Ligui; Zeng, Xiangying; Sheng, Guoying; Fu, Jiamo

2011-10-01

In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of ∑(20)PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 ± 152 pg/m(3) and 5.48 ± 1.28 pg/m(3), respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. Copyright © 2011 Elsevier Ltd. All rights reserved.

Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

OpenAIRE

Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

1990-01-01

Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride),...

Distribution of polybrominated diphenyl ethers in sediments of the Pearl River Delta and adjacent South China Sea.

Science.gov (United States)

Mai, Bixian; Chen, Shejun; Luo, Xiaojun; Chen, Laiguo; Yang, Qingshu; Sheng, Guoying; Peng, Pingan; Fu, Jiamo; Zeng, Eddy Y

2005-05-15

Spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs) in sediments of the Pearl River Delta (PRD) and adjacent South China Sea (SCS) of southern China were examined. A total of 66 surface sediment samples were collected and analyzed to determine the concentrations of 10 PBDE congeners (BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209). The concentrations of BDE-209 and SigmaPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) ranged from 0.4 to 7340 and from 0.04 to 94.7 ng/g, respectively. The SigmaPBDEs concentrations were mostly transportation. The PBDE patterns in the SCS and Pearl River Estuary sediments were similar to those in sediments of the Zhujiang and Dongjiang Rivers, reflecting the widespread influence from local inputs. Analyses of two short sediment cores collected from the Pearl River Estuary showed that concentrations of BDE-209 rapidly increased in the upper layers of both cores, coincident with the growth of the electronics manufacturing capacities in the PRD region. The major sources of PBDEs were probably waste discharges from the cities of Guangzhou, Dongguan, and Shenzhen, the three fastest growing urban centers in the PRD.

Certification of Mass Fractions of Polycyclic Aromatic Hydrocarbons, Organochlorines and Polybrominated Diphenyl Ethers in IAEA-459 Marine Sediment Sample

International Nuclear Information System (INIS)

2017-01-01

This publication describes the production of certified reference material IAEA-459, which is produced following ISO Guides 34:2009 and 35:2006. This certified reference material is a sediment sample with certified mass fractions of polycyclic aromatic hydrocarbons, organochlorines and polybrominated diphenyl ethers. The assigned final values and their associated uncertainties were derived from robust statistics on the results provided by selected laboratories with demonstrated technical and quality competence, following the guidance given in the ISO Guides. The material is used for quality control and assessment of method performance for a number of organic analytes listed in the Stockholm Convention on Persistent Organic Pollutants as well as other pollutants listed as priority substances included in many environment monitoring programmes.

Occurrence and levels of polybrominated diphenyl ethers (PBDEs) in house dust and hair samples from Northern Poland; an assessment of human exposure.

Science.gov (United States)

Król, Sylwia; Namieśnik, Jacek; Zabiegała, Bożena

2014-09-01

Polybrominated diphenyl ethers (PBDEs) are among most ubiquitous compounds to be found in indoor environment and ingestion of household dust is considered an important route of exposure to PBDEs, especially in toddlers and young children. The present work reported concentration levels of PBDE congeners (PBDE-28, -47, -99, -100, -153, -154, -183 and -209) in hair and dust samples from selected households from Northern Poland. The concentrations of PBDEs in dust ranged from human hair. PBDE-209 was reported the dominating congener. Two separated exposure scenarios (mean and 95th percentile) were used to provide a comprehensive overview of possible risks arising from ingestion of household dust. The estimated exposure to ∑PBDEs via ingestion of household dust varied from 21 to 92ngd(-1) in toddlers and from 3.7 to 20ngd(-1) in adults. By comparison of correlation between the concentrations of PBDEs in paired hair and dust samples the present work also investigated the possibility of use of hair for reflecting the actual exposure to PBDEs in humans. Finally the possible uncertainties associated with exposure assessment were investigated in the present study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Halogenated arsenenes as Dirac materials

International Nuclear Information System (INIS)

Tang, Wencheng; Sun, Minglei; Ren, Qingqiang; Wang, Sake; Yu, Jin

2016-01-01

Highlights: • We have revealed the presence of Dirac cone in fully-halogenated arsenene compounds. • All fully-halogenated arsenene except As_2I_2 would spontaneously form and stable in defending the thermal fluctuation in room temperature. - Abstract: Arsenene is the graphene-like arsenic nanosheet, which has been predicted very recently [S. Zhang, Z. Yan, Y. Li, Z. Chen, and H. Zeng, Angewandte Chemie, 127 (2015) 3155–3158]. Using first-principles calculations, we systematically investigate the structures and electronic properties of fully-halogenated arsenenes. Formation energy analysis reveals that all the fully-halogenated arsenenes except iodinated arsenene are energetically favorable and could be synthesized. We have revealed the presence of Dirac cone in fully-halogenated arsenene compounds. They may have great potential applications in next generation of high-performance devices.

Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

Directory of Open Access Journals (Sweden)

Mohamed F. Abdel-Megeed

2013-01-01

Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

Generation and alteration of the defects induced by particle irradiation and electromagnetic radiation in alkali halogen compounds

International Nuclear Information System (INIS)

Nistor, L.C.

1979-01-01

Interactions between electron beams, CO 2 - laser radiation and alkali halogen compound have led to interesting results: 1. The development of two types of F-centre respectively in normal lattice or near the dislocations. 2. The beginning of metal colloids development process at low temperature when a thermal treatment is applied. 3. An experimental confirmation of the Pooley-Hersh model for crystal defects has been brought up. 4. The surface penetration is an explosive process. 5. Surface polygonizations were also investigated. A model has been proposed to describe the destructive channels development within alkali halogen crystals with molecular anions impurities of less than 10 ppm. KCl monocrystals of advanced purity level was prepared for building up passive optical components of strong CO 2 lasers. (author)

Anaerobic biodegradation of halogenated and nonhalogenated N-, s-, and o-heterocyclic compounds in aquifer slurries

Science.gov (United States)

Adrian, Neal R.; Suflita, Joseph M.

1994-01-01

The fate of several halogenated and nonhalogenated heterocyclic compounds in anoxic aquifer slurries was investigated Substrate depletion and methane formation were monitored in serum bottle incubations by HPLC and GC, respectively Pyridine, pyrimidine, thiophene, and furan were not mineralized following an 11-month incubation, but the corresponding carboxylated or oxygenated compounds were That is, >74% of the theoretically expected amount of methane was recovered from nicotinic acid, uracil, or 2-furoic acid Chlorinated derivatives, like 2 chloro- or 6-chloronicotinic acid, as well as 4 chloro- and 5-chlorouracil resisted mineralization However, 5-bromouracil was reductively dehalogenated to stoichiometric amounts of uracil, whereas 2-chloropyrimidine was metabolized to a more polar unidentified compound that resisted further anaerobic biodegradation Microorganisms acclimated to 5-bromouracil were unable to transform 4 chloro or 5 chlorouracil These findings illustrate how the structure of heterocyclic contaminants influences their susceptibility to anaerobic decay

PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)

Science.gov (United States)

Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

Synthesis and characterization of novel polyamide-ethers based on bis-imidazole containing bulky aryl pendant groups

Directory of Open Access Journals (Sweden)

Seyed Mahdi Saadati

2013-01-01

Full Text Available A series of novel polyamide-ethers (PAEs based on bis-imidazole containing bulky aryl pendant groups was prepared by direct polycondensation of a diamine, 4-(1-(4-(4-(2-(4-aminophenyl-4,5-diphenyl-1H-imidazol-1-ylphenoxyphenyl-4,5-diphenyl-1H-imidazol-2-ylbenzenamine (DABI, and various dicarboxylic acids. All the resulting polyamide-ethers were amorphous with inherent viscosities ranged from 0.52 to 0.61 dL/g and were readily soluble in many organic solvents which could be solution-cast into transparent and tough films. The glass transition temperatures (Tg of these polymers were affected considerably by their chemical structure and ranged from 230 to 310 ºC. They had useful levels of thermal stability associated with relatively high temperatures of 10% weight loss (T10 in the range of 329-399 ºC in air atmosphere.

Oxidation reactivity of 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) by Compound I model of cytochrome P450s

Institute of Scientific and Technical Information of China (English)

Zhongyu Wang; Zhiqiang Fu; Qi Yu; Jingwen Chen

2017-01-01

Alternative brominated flame retardants (BFRs) have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers (PBDEs).For risk assessment of these alternatives,knowledge of their metabolism via cytochrome P450 enzymes is needed.We have previously proved that density functional theory (DFT) is able to predict the metabolism of PBDEs by revealing the molecular mechanisms.In the current study,the reactivity of 1,2-bis(2,4,6-tribromophenoxy)ethane and structurally similar chemicals with the Compound I model representing the active site of P450 enzymes was investigated.The DFT calculations delineated reaction pathways which lead to reasonable explanations for products that were detected by wet experiments,meanwhile intermediates which cannot be determined were also proposed.Results showed that alkyl hydrogen abstraction will lead to bis(2,4,6-tribromophenoxy)ethanol,which may undergo hydrolysis yielding 2,4,6-tribromophenol,a neurotoxic compound.In addition,a general pattern of oxidation reactivity regarding the 2,4,6-tribromophenyl moiety was observed among several model compounds.Our study has provided insights for convenient evaluation of the metabolism of other structurally similar BFRs.

Palladium-Catalyzed Formal Cross-Coupling of Diaryl Ethers with Amines: Slicing the 4-O-5 Linkage in Lignin Models.

Science.gov (United States)

Zeng, Huiying; Cao, Dawei; Qiu, Zihang; Li, Chao-Jun

2018-03-26

Lignin is the second most abundant organic matter on Earth, and is an underutilized renewable source for valuable aromatic chemicals. For future sustainable production of aromatic compounds, it is highly desirable to convert lignin into value-added platform chemicals instead of using fossil-based resources. Lignins are aromatic polymers linked by three types of ether bonds (α-O-4, β-O-4, and 4-O-5 linkages) and other C-C bonds. Among the ether bonds, the bond dissociation energy of the 4-O-5 linkage is the highest and the most challenging to cleave. To date, 4-O-5 ether linkage model compounds have been cleaved to obtain phenol, cyclohexane, cyclohexanone, and cyclohexanol. The first example of direct formal cross-coupling of diaryl ether 4-O-5 linkage models with amines is reported, in which dual C(Ar)-O bond cleavages form valuable nitrogen-containing derivatives. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pilot-scale incineration of wastes with high content of chlorinated and non-halogenated organophosphorus flame retardants used as alternatives for PBDEs.

Science.gov (United States)

Matsukami, Hidenori; Kose, Tomohiro; Watanabe, Mafumi; Takigami, Hidetaka

2014-09-15

Chlorinated and non-halogenated organophosphorus flame retardants (OPFRs) including tris(2-chloroisopropyl) phosphate (TCIPP), diethylene glycol bis(di(2-chloroisopropyl) phosphate) (DEG-BDCIPP), triphenyl phosphate (TPHP), and bisphenol A bis(diphenyl phosphate) (BPA-BDPP) have been used increasingly as alternatives to polybrominated diphenyl ethers and other brominated flame retardants. For this study, five batches of incineration experiments of wastes containing approximately 1% of TCIPP, DEG-BDCIPP, TPHP, and BPA-BDPP were conducted using a pilot-scale incinerator. Destruction and emission behaviors of OPFRs were investigated along with the effects on behaviors of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), and pentachlorophenol (PCP). Incineration conditions were chosen according to current regulations for waste incinerators in Japan and UNEP. The OPFRs in the input materials were mainly destroyed in the primary combustion with destruction efficiencies greater than 99.999%. Concentrations of the OPFRs in the exhaust gases and ash were, respectively, incineration. Inputs of chlorinated OPFRs did not affect the formation markedly. Destruction and emission behaviors of unintentional POPs were investigated. Emissions of such POPs in exhaust gases and the ash were lower than the Japanese and international standards. Results show that even in wastes with high contents of chlorinated and non-halogenated OPFRs, waste incineration by the current regulations for the waste incinerators can control environmental emissions of OPFRs and unintentional POPs. Incineration is regarded as a best available technology (BAT) for waste management systems. Copyright © 2014 Elsevier B.V. All rights reserved.

Thermodynamic properties of 4-tert-butyl-diphenyl oxide

International Nuclear Information System (INIS)

Druzhinina, A.I.; Pimenova, S.M.; Tarazanov, S.V.; Nesterova, T.N.; Varushchenko, R.M.

2015-01-01

Highlights: • The sample of the 4-tert-butyl-diphenyl oxide was synthesized and purified. • Heat capacities, energy of combustion, saturation vapor pressures were measured. • The temperature, the enthalpy and the entropy of fusion were determined. • The enthalpy of sublimation at T = 298.15 K was derived. • The main thermodynamic functions and functions of formation were computed. - Abstract: The main thermodynamic functions (changes of the entropy, enthalpy, and Gibbs free energy) and functions of formation at T = 298.15 K of 4-tert-butyl-diphenyl oxide in condensed and ideal gas states were computed on the basis of experimental results obtained. The heat capacities of 4-tert-butyl-diphenyl oxide was measured by vacuum adiabatic calorimetry over the temperature range (8 to 371) K. The temperature, the enthalpy and the entropy of fusion were determined. The energy of combustion of the sample was determined by static-bomb combustion calorimetry. The saturation vapor pressures of the substance were measured by dynamic transpiration method over the temperature and pressure intervals (298 to 325) K and (0.05 to 1.2) Pa. The enthalpy of sublimation at T = 298.15 K was derived. The contribution of O-(2C b ) group (where C b is the carbon atom in a benzene ring) into the absolute entropies of diphenyl oxide derivatives was assessed

Selective Halogen-Lithium Exchange of 1,2-Dihaloarenes for Successive [2+4] Cycloadditions of Arynes and Isobenzofurans

Directory of Open Access Journals (Sweden)

Shohei Eda

2015-10-01

Full Text Available Successive [2+4] cycloadditions of arynes and isobenzofurans by site-selective halogen-lithium exchange of 1,2-dihaloarenes were developed, allowing the rapid construction of polycyclic compounds which serve as a useful synthetic intermediates for the preparation of various polyacene derivatives.

Debromination of polybrominated diphenyl ethers by Ni/Fe bimetallic nanoparticles: Influencing factors, kinetics, and mechanism

International Nuclear Information System (INIS)

Fang Zhanqiang; Qiu Xinhong; Chen Jinhong; Qiu Xiuqi

2011-01-01

Polybrominated diphenyl ethers have been identified as a new class of organic pollutants with ecological risk due to their toxicity, bioaccumulation, and global distribution. Proper remediation technologies are needed to remove them from the environment. In this paper, Ni/Fe bimetallic nanoparticles were synthesized by chemical deposition and used to degrade decabromodiphenyl ether (BDE209). The characteristics of Ni/Fe nanoparticles were analyzed by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and Brunnaer-Emmett-Teller surface area analysis. Ni/Fe bimetallic nanoparticles with diameters in the order of 20-50 nm could effectively degrade BDE209 in the solvent (tetrahydrofuran/water). Influence factors, such as Ni/Fe nanoparticle dosage, initial BDE209 concentration, and Ni loading, on the removal of BDE209 were studied. The results indicated that the degradation of BDE209 followed pseudo-first-order kinetics, and the degradation rate of BDE209 increased with increasing the amount of nano Ni/Fe particles, Ni/Fe ratio, and decreasing the initial concentration of BDE209. Through analyzed the mass balance of the BDE209 removal, degradation was the main process of BDE209 removal. The mechanism of debromination was deduced by analyzing the reaction products using gas chromatography-mass spectrometry, the bromide ion in the solution and varying the solvent conditions. Stepwise hydrogen reduction is the main process of debromination, and the hydrion play an important role in the reaction. Moreover, the experiment of long term performance and leaching of Ni were also carried out to test the stability and durability of Ni/Fe nanoparticles in BDE209 degradation.

Kinetics and Pathways for the Debromination of Polybrominated Diphenyl Ethers by Bimetallic and Nanoscale Zerovalent Iron: Effects of Particle Properties and Catalyst

Science.gov (United States)

Zhuang, Yuan; Jin, Luting; Luthy, Richard G.

2012-01-01

Polybrominated diphenyl ethers (PBDEs) are recognized as a new class of widely-distributed and persistent contaminants for which effective treatment and remediation technologies are needed. In this study, two kinds of commercially available nanoscale Fe° slurries (Nanofer N25 and N25S), a freeze-dried laboratory-synthesized Fe° nanoparticle (nZVI), and their palladized forms were used to investigate the effect of particle properties and catalyst on PBDE debromination kinetics and pathways. Nanofers and their palladized forms were found to debrominate PBDEs effectively. The laboratory-synthesized Fe° nanoparticles also debrominated PBDEs, but were slower due to deactivation by the freeze-drying and stabilization processes in the laboratory synthesis. An organic modifier, polyacrylic acid (PAA), bound on N25S slowed PBDE debromination by a factor of three to four compared to N25. The activity of palladized nZVI (nZVI/Pd) was optimized at 0.3 Pd/Fe wt% in our system. N25 could debrominate selected environmentally-abundant PBDEs, including BDE 209, 183, 153, 99, and 47, to end products di-BDEs, mono-BDEs and diphenyl ether (DE) in one week, while nZVI/Pd (0.3 Pd/Fe wt%) mainly resulted in DE as a final product. Step-wise major PBDE debromination pathways by unamended and palladized Fe° are described and compared. Surface precursor complex formation is an important limiting factor for palladized Fe° reduction as demonstrated by PBDE pathways where steric hindrance and rapid sequential debromination of adjacent bromines play an important role. PMID:22732301

Experimental and theoretical investigation on the molecular structure, spectroscopic and electric properties of 2,4-dinitrodiphenylamine, 2-nitro-4-(trifluoromethyl)aniline and 4-bromo-2-nitroaniline

Science.gov (United States)

Hernández-Paredes, Javier; Hernández-Negrete, Ofelia; Carrillo-Torres, Roberto C.; Sánchez-Zeferino, Raúl; Duarte-Moller, Alberto; Alvarez-Ramos, Mario E.

2015-10-01

2,4-Dinitrodiphenylamine (I), 2-nitro-4-(trifluoromethyl)aniline (II) and 4-bromo-2-nitroaniline (III) have been investigated by DFT and experimental FTIR, Raman and UV-Vis spectroscopies. The gas-phase molecular geometries were consistent with similar compounds already reported in the literature. From the vibrational analysis, the main functional groups were identified and their absorption bands were assigned. Some differences were found between the calculated and the experimental UV-Vis spectra. These differences were analyzed and explained in terms of the TD-DFT/B3LYP limitations, which were mainly attributed to charge-transfer (CT) effects. These findings were in agreement with previous works, which reported that TD-DFT/B3LYP calculations diverge from experimental results when the electronic transitions involve CT. Despite this, TD-DFT/B3LYP calculations provided satisfactory results and a detailed description of the electronic transitions involved in the absorption bands of the UV-Vis spectra. In terms of the NLO properties, it was found that compound (I) is a good candidate for NLO applications and deserves further study due to its good β values. However, the β values for compounds (II) and (III) were negatively affected compared to those found on o-nitroaniline.

Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

Energy Technology Data Exchange (ETDEWEB)

Binelli, A. [Department of Biology, Via Celoria 26, University of Milan, 20133 Milan (Italy)], E-mail: andrea.binelli@unimi.it; Guzzella, L.; Roscioli, C. [IRSA-CNR, 20047 Brugherio (Milan) (Italy)

2008-06-15

Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with {sigma}PBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447 ng g{sup -1} lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47 > -99 > -100 > -209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide. - This study shows the first data of PBDE contamination in freshwater invertebrates from Mediterranean basin.

Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

International Nuclear Information System (INIS)

Binelli, A.; Guzzella, L.; Roscioli, C.

2008-01-01

Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with ΣPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447 ng g -1 lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47 > -99 > -100 > -209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide. - This study shows the first data of PBDE contamination in freshwater invertebrates from Mediterranean basin

Estimating stepwise debromination pathways of polybrominated diphenyl ethers with an analogue Markov Chain Monte Carlo algorithm.

Science.gov (United States)

Zou, Yonghong; Christensen, Erik R; Zheng, Wei; Wei, Hua; Li, An

2014-11-01

A stochastic process was developed to simulate the stepwise debromination pathways for polybrominated diphenyl ethers (PBDEs). The stochastic process uses an analogue Markov Chain Monte Carlo (AMCMC) algorithm to generate PBDE debromination profiles. The acceptance or rejection of the randomly drawn stepwise debromination reactions was determined by a maximum likelihood function. The experimental observations at certain time points were used as target profiles; therefore, the stochastic processes are capable of presenting the effects of reaction conditions on the selection of debromination pathways. The application of the model is illustrated by adopting the experimental results of decabromodiphenyl ether (BDE209) in hexane exposed to sunlight. Inferences that were not obvious from experimental data were suggested by model simulations. For example, BDE206 has much higher accumulation at the first 30 min of sunlight exposure. By contrast, model simulation suggests that, BDE206 and BDE207 had comparable yields from BDE209. The reason for the higher BDE206 level is that BDE207 has the highest depletion in producing octa products. Compared to a previous version of the stochastic model based on stochastic reaction sequences (SRS), the AMCMC approach was determined to be more efficient and robust. Due to the feature of only requiring experimental observations as input, the AMCMC model is expected to be applicable to a wide range of PBDE debromination processes, e.g. microbial, photolytic, or joint effects in natural environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mild copper-catalyzed trifluoromethylation of terminal alkynes using an electrophilic trifluoromethylating reagent

KAUST Repository

Weng, Zhiqiang

2012-03-01

A catalytic process for trifluoromethylation of terminal alkynes with Togni\\'s reagent has been developed, affording trifluoromethylated acetylenes in good to excellent yields. The reaction is conducted at room temperature and exhibits tolerance to a range of functional groups. © 2012 Elsevier Ltd. All rights reserved.

Gridded field observations of polybrominated diphenyl ethers in soils of North China.

Science.gov (United States)

Liu, Di; Ma, Jin; Qiu, Xinghua; Zhao, Yifan; Lin, Yan; Yang, Qiaoyun; Gao, Zhenji; Zhu, Tong

2014-05-01

Polybrominated diphenyl ethers (PBDEs) were measured in 87 soil samples collected from North China. Eleven PBDE congeners (BDE28, 47, 49, 66, 99, 100, 119, 183, 196, 203, and 209) were identified with a high frequency of detection (84-100 %) in soil samples, and their frequencies were used for statistical analysis in the present study. PBDE concentrations ranged from 0.08 to 8260 ng/g with a mean of 202 ng/g, thus indicating severe pollution at these sample sites. BDE209 was the predominant congener with concentrations of 0.08-8140 ng/g (mean 188). Analysis of the spatial distribution of PBDEs in North China soils indicated that relatively high concentrations of both lower- and higher-brominated BDEs were present in Shandong Province, and a decreasing trend in PBDE concentrations from the east toward the west of North China was observed. Source identification analysis suggested that Jinghai County in Tianjin and the coastal area of Laizhou Bay, Shandong province, were the major sources in North China. The sources in Jinghai County were connected with the dismantling of electronic waste, whereas the sources in the coastal area of Laizhou Bay were connected with the production of PBDEs. Modeling results showed that the distance between the sampling sites and these point sources had a large influence on the transfer of PBDEs.

Zn2+, Cd2+, Hg2+ thiolates - derivatives of 2, 3, 5-trifluoro-4,6-bis(trifluoromethyl)thiophenol and heptafluoro-2-thionaphthol

International Nuclear Information System (INIS)

Larionov, S.V.; Kirichenko, V.N.; Platonov, V.E.; Maksimov, A.M.; Rodionov, P.P.; Fadeeva, V.P.; Oglezneva, I.M.; Lisojvan, V.I.; AN SSSR, Novosibirsk

1992-01-01

Zn 2+ , Cd 2+ , Hg 2+ coordination compounds with 2, 3, 5 -trifluoro- 4,6 bis(trifluoromethyl)trhiophenol (MHal) and heptafluoro-2-thionophthal (HT) of ZnHal 2 (CH 3 OH), CdHal 2 , HgHal 2 and MT 2 (M=Zn, Cd, Hg) composition, are obtained. Complexes are studied using thermal and X-ray phase analysis, vapour phase osmometry and IR spectroscopy, ZnHal 2 (CH 3 OH), CdHal 2 , ZnT 2 , HgHfl 2 , HgT 2 compounds in acetone solutions are in monomeric state, while in CdT 2 commeric particles. Frequencies of mostly valent vibrations of Cd-S bond are observed at 241 (CdHal 2 ), 225 (CdT 2 )

Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

Energy Technology Data Exchange (ETDEWEB)

Yogui, G.T. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: gtyogui@ocean.tamu.edu; Sericano, J.L. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: jsericano@gerg.tamu.edu

2009-03-15

Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs.

Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

International Nuclear Information System (INIS)

Yogui, G.T.; Sericano, J.L.

2009-01-01

Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs

Quadrupole coupling constants and isomeric Moessbauer shifts for halogen-containing gold, platinum, niobium, tantalum and antimony compounds

International Nuclear Information System (INIS)

Poleshchuk, O. K.; Branchadell, V.; Ritter, R. A.; Fateev, A. V.

2008-01-01

We have analyzed by means of Density functional theory calculations the nuclear quadrupole coupling constants of a range of gold, antimony, platinum, niobium and tantalum compounds. The geometrical parameters and halogen nuclear quadrupole coupling constants obtained by these calculations substantially corresponded to the data of microwave and nuclear quadrupole resonance spectroscopy. An analysis of the quality of the calculations that employ pseudo-potentials and all-electron basis sets for the halogen compounds was carried out. The zero order regular approximation (ZORA) method is shown to be a viable alternative for the calculation of halogen coupling constants in molecules. In addition, the ZORA model, in contrast to the pseudo-potential model, leads to realistic values of all metal nuclear quadrupole coupling constants. From Klopman's approach, it follows that the relationship between the electrostatic bonding and covalent depends on the nature of the central atom. The results on Moessbauer chemical shifts are also in a good agreement with the coordination number of the central atom.

Quadrupole coupling constants and isomeric Moessbauer shifts for halogen-containing gold, platinum, niobium, tantalum and antimony compounds

Energy Technology Data Exchange (ETDEWEB)

Poleshchuk, O. K., E-mail: poleshch@tspu.edu.ru [Tomsk State Pedagogical University (Russian Federation); Branchadell, V. [Universitat Autonoma de Barcelona, Departament de Quimica (Spain); Ritter, R. A.; Fateev, A. V. [Tomsk State Pedagogical University (Russian Federation)

2008-01-15

We have analyzed by means of Density functional theory calculations the nuclear quadrupole coupling constants of a range of gold, antimony, platinum, niobium and tantalum compounds. The geometrical parameters and halogen nuclear quadrupole coupling constants obtained by these calculations substantially corresponded to the data of microwave and nuclear quadrupole resonance spectroscopy. An analysis of the quality of the calculations that employ pseudo-potentials and all-electron basis sets for the halogen compounds was carried out. The zero order regular approximation (ZORA) method is shown to be a viable alternative for the calculation of halogen coupling constants in molecules. In addition, the ZORA model, in contrast to the pseudo-potential model, leads to realistic values of all metal nuclear quadrupole coupling constants. From Klopman's approach, it follows that the relationship between the electrostatic bonding and covalent depends on the nature of the central atom. The results on Moessbauer chemical shifts are also in a good agreement with the coordination number of the central atom.

Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

Science.gov (United States)

Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

1990-01-01

Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded. PMID:2339874

Synthesis of 4-Halogenated 3-Fluoro-6-methoxyquinolines: Key Building Blocks for the Synthesis of Antibiotics

DEFF Research Database (Denmark)

Flagstad, Thomas; Petersen, Mette Terp; Hinnerfeldt, Daniel Michael

2014-01-01

A practical and scalable 4-step route is presented for the synthesis of 4-bromo-3-fluoro-6-methoxyoquinoline and 3-fluoro-4-iodo-6-methoxyoquinoline from readily available 2,4-dichloro-3-fluoroquinoline with an overall yield of 81-85%. Halogenated quinoline building blocks have found much use in ...... in antimicrobial drug discovery, and the method reported here would be useful for the synthesis of these compounds. © Georg Thieme Verlag....

trans-Carbonylchloridobis[diphenyl(4-vinylphenylphosphane-κP]rhodium(I

Directory of Open Access Journals (Sweden)

Reinout Meijboom

2012-05-01

Full Text Available In the title compound, trans-[RhCl(C20H17P2(CO], the RhI atom is situated on a center of symmetry, resulting in a statistical 1:1 disorder of the chloride [Rh—Cl = 2.383 (2 Å] and carbonyl [Rh—C = 1.752 (7 Å] ligands. The distorted trans square-planar environment is completed by two P atoms [Rh—P = 2.3251 (4 Å] from two diphenyl(4-vinylphenylphosphane ligands. The vinyl group is disordered over two sets of sites in a 0.668 (10:0.332 (10 ratio. The crystal packing exhibits weak C—H...Cl and C—H...O hydrogen bonds and π–π interactions between the phenyl rings of neighbouring molecules, with a centroid–centroid distance of 3.682 (2 Å.

Emission factors of polybrominated diphenyl ethers (PBDEs) from plastics processing and recycling facilities

Energy Technology Data Exchange (ETDEWEB)

Sakai, Shin-ichi; Hirai, Yasuhiro [National Institute for Environmental Studies, Tsukuba (Japan); Ota, Shizuko; Sudo, Kinichi [Ministry of Environment (Japan)

2004-09-15

With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations based on the measured values are few. In light of the situation, PBDE emission concentrations from processing facilities of flame retardant plastics and recycling facilities of home electric appliances are measured in practice to presume material flow of PBDE and to estimate emission factors and inventories from each phase of life cycles. The validities of emission factors are examined in comparison to measured values of atmospheric depositions surroundings, which are close to sources.

Quantitative structure-property relationships for octanol-water partition coefficients of polybrominated diphenyl ethers.

Science.gov (United States)

Li, Linnan; Xie, Shaodong; Cai, Hao; Bai, Xuetao; Xue, Zhao

2008-08-01

Theoretical molecular descriptors were tested against logK(OW) values for polybrominated diphenyl ethers (PBDEs) using the Partial Least-Squares Regression method which can be used to analyze data with many variables and few observations. A quantitative structure-property relationship (QSPR) model was successfully developed with a high cross-validated value (Q(cum)(2)) of 0.961, indicating a good predictive ability and stability of the model. The predictive power of the QSPR model was further cross-validated. The values of logK(OW) for PBDEs are mainly governed by molecular surface area, energy of the lowest unoccupied molecular orbital and the net atomic charges on the oxygen atom. All these descriptors have been discussed to interpret the partitioning mechanism of PBDE chemicals. The bulk property of the molecules represented by molecular surface area is the leading factor, and K(OW) values increase with the increase of molecular surface area. Higher energy of the lowest unoccupied molecular orbital and higher net atomic charge on the oxygen atom of PBDEs result in smaller K(OW). The energy of the lowest unoccupied molecular orbital and the net atomic charge on PBDEs oxygen also play important roles in affecting the partition of PBDEs between octanol and water by influencing the interactions between PBDEs and solvent molecules.

Influences of binding to dissolved organic matter on hydrophobic organic compounds in a multi-contaminant system: Coefficients, mechanisms and ecological risks

International Nuclear Information System (INIS)

Li, Yi-Long; He, Wei; Liu, Wen-Xiu; Kong, Xiang-Zhen; Yang, Bin; Yang, Chen; Xu, Fu-Liu

2015-01-01

The complexation flocculation (CF) method was successfully employed to identify binding coefficients (K_d_o_c) of specific organic contaminants to dissolved organic matter (DOM, often indicated by dissolved organic carbon, DOC) in a multi-contaminant hydrophobic organic contaminant (HOC) system. K_d_o_c values were obtained for most of the evaluated 33 HOCs, indicating the feasibility and applicability of the CF method in a multi-contaminant system. Significant positive correlations were observed between binding coefficients and octanol–water partition coefficients (K_o_w) for organic halogen compounds, such as polybrominated diphenyl ethers (PBDEs) (R"2 = 0.95, p < 0.05) and organic chlorine pesticides (OCPs) (methoxychlor excluded, R"2 = 0.82, p < 0.05). The positive correlations identified between the lgK_d_o_c and lgBCF (bioconcentration factor) for PBDEs and OCPs, as well as the negative correlation observed for polycyclic aromatic hydrocarbons (PAHs), indicated that different binding or partition mechanisms between PAHs and organic halogen compounds exist. These differences further result in discriminative competition partitions of HOCs between DOM and organisms. Assuming that only freely dissolved HOCs are bioconcentrative, the results of DOM-influenced bioconcentration factor (BCF_D_O_M) and DOM-influenced lowest observed effect level (LOEL_D_O_M) indicate that the ecological risk of HOCs is decreased by DOM. - Highlights: • Complexing-flocculation is viable in measuring K_d_o_c in a multi-polluted system. • The binding mechanisms between PAHs and organic halogens were different. • DOM should be considered when assessing ecological risk of HOCs in natural ecosystem. - Assuming only freely dissolved HOCs are effective, bioconcentration factors and ecological risks of HOCs are decreased by dissolved organic matter via binding.

Distribution of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in municipal solid waste incinerators

International Nuclear Information System (INIS)

Wang, L.-C.; Hsi, H.-C.; Wang, Y.-F.; Lin, S.-L.; Guo-Ping Chang-Chien

2010-01-01

The stack flue gases and the ashes in different units of two municipal solid waste incinerators (MSWIs) are sampled to investigate the characteristics of polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Bottom ashes (BA) exhibited much higher PBDD/F (8.11-52.2 pg TEQ/g) and PBDE contents (20.4-186 ng/g) than those of fly ashes (0.0932-2.02 pg TEQ/g and 0.332-25.5 ng/g), revealing that the PBDD/Fs and PBDEs in the feeding waste may not be completely destroyed. The PBDE concentrations/contents in the stack flue gases (26.1-109 ng/Nm 3 ) and in the BA (20.4-186 ng/g) of the MSWIs could reach three orders higher than those in the atmosphere and reference soils. PBDE contributions to the environment from the stack flue gases or the reutilization of BA of MSWIs should not be ignored from the developing PBDE inventory. - Municipal solid waste incinerators contributed PBDEs and PBDD/Fs to the environment through stack flue gases and reutilization of bottom ashes.

Marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids

Energy Technology Data Exchange (ETDEWEB)

Kucklick, John R.; Pugh, Rebecca S.; Becker, Paul R. [Hollings Marine Laboratory, National Institute of Standards and Technology (NIST), Charleston, SC (United States); Schantz, Michele M.; Porter, Barbara J.; Poster, Dianne L.; Leigh, Stefan; Wise, Stephen A. [NIST, Analytical Chemistry Division, Gaithersburg, MD (United States); Rowles, Teri K. [National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD (United States)

2010-05-15

The National Institute of Standards and Technology (NIST) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. Standard Reference Material (SRM) 1945 Organics in Whale Blubber was recertified for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, and polybrominated diphenyl ether (PBDE) congeners. SRM 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congeners, coplanar PCBs, and methoxylated PBDE congeners which are natural products. NIST also has assigned mass fraction values, as a result of interlaboratory comparison exercises, for PCB congeners, organochlorine pesticides, PBDE congeners, and fatty acids in six homogenate materials produced from marine mammal blubber or serum. The materials are available from NIST upon request; however, the supply is very limited for some of the materials. The materials include those obtained from pilot whale blubber (Homogenates III and IV), Blainville's beaked whale blubber (Homogenate VII), polar bear fat (Homogenate VI), and California sea lion serum (Marine Mammal Control Material-1 Serum) and blubber (Homogenate V). (orig.)

Removal of halogenated organic compounds in landfill gas by top covers containing zero-valent iron

DEFF Research Database (Denmark)

Scheutz, Charlotte; Winther, K.; Kjeldsen, Peter

2000-01-01

Transformation of gaseous CCl3F and CCl4 by zero-valent iron was studied in systems unsaturated with water under anaerobic conditionssin an N2 gas and in a landfill gas atmosphere. The transformation was studied in batch as well as flow-through column tests. In both systems, the transformation....... During continuous aerobic conditions, the transformation of CCl3F decreased toward zero. Model calculations show that use of zero-valent iron in landfill top covers is a potential treatment technology for emission reduction of halogenated trace compounds from landfills....

Characteristics of Polybrominated Diphenyl Ethers Released from Thermal Treatment and Open Burning of E-Waste.

Science.gov (United States)

Li, Ting-Yu; Zhou, Jun-Feng; Wu, Chen-Chou; Bao, Lian-Jun; Shi, Lei; Zeng, Eddy Y

2018-04-17

Primitive processing of e-waste potentially releases abundant organic contaminants to the environment, but the magnitudes and mechanisms remain to be adequately addressed. We conducted thermal treatment and open burning of typical e-wastes, that is, plastics and printed circuit boards. Emission factors of the sum of 39 polybrominated diphenyl ethers (∑ 39 PBDE) were 817-1.60 × 10 5 ng g -1 in thermal treatment and nondetected-9.14 × 10 4 ng g -1 , in open burning. Airborne particles (87%) were the main carriers of PBDEs, followed by residual ashes (13%) and gaseous constituents (0.3%), in thermal treatment, while they were 30%, 43% and 27% in open burning. The output-input mass ratios of ∑ 39 PBDE were 0.12-3.76 in thermal treatment and 0-0.16 in open burning. All PBDEs were largely affiliated with fine particles, with geometric mean diameters at 0.61-0.83 μm in thermal degradation and 0.57-1.16 μm in open burning from plastic casings, and 0.44-0.56 and nondetected- 0.55 μm, from printed circuit boards. Evaporation and reabsorption may be the main emission mechanisms for lightly brominated BDEs, but heavily brominated BDEs tend to affiliate with particles from heating or combustion. The different size distributions of particulate PBDEs in emission sources and adjacent air implicated a noteworthy redisposition process during atmospheric dispersal.

IRON(III) NITRATE-CATALYZED FACILE SYNTHESIS OF DIPHENYLMETHYL (DPM) ETHERS FROM ALCOHOLS

Science.gov (United States)

Diphenyl methyl (DPM) ethers constitute important structural portion of some pharmaceutical entities and also as protective group for hydroxyl groups in synthetic chemistry. DPM ethers are normally prepared using concentrated acids or base as catalysts, which may result in the fo...

Dynamic modeling predicts continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass (Micropterus dolomiu) post phase-out due to invasive prey and shifts in predation

International Nuclear Information System (INIS)

Wallace, Joshua S.; Blersch, David M.

2015-01-01

Unprecedented food chain links between benthic and pelagic organisms are often thought to disrupt traditional contaminant transport and uptake due to changes in predation and mobilization of otherwise sequestered pollutants. A bioaccumulation model for polybrominated diphenyl ethers (PBDEs) is developed to simulate increases in biotic congener loads based upon trophic transfer through diet and gill uptake for a Lake Erie food chain including two invasive species as a benthic-pelagic link. The model utilizes species-specific bioenergetic parameters in a four-level food chain including the green alga Scenedesmus quadricauda, zebra mussels (Dreissena polymorpha), round goby (Appollonia melanostoma), and the smallmouth bass (Micropterus dolomiu). The model was calibrated to current biotic concentrations and predicts an increase in contaminant load by almost 48% in the upper trophic level in two years. Validation to archival data resulted in <2% error from reported values following a two-year simulation. - Highlights: • A dynamic model assesses continued bioaccumulation of PBDEs in predators of invasive prey. • The model incorporates novel benthic-pelagic energy links due to invasive prey. • Increases in total PBDEs in smallmouth bass due to invasive energy pathways are simulated. • The model is validated to archival data obtained prior to invasion of zebra mussels and round goby. - A dynamic model is developed to simulate continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass due to emerging benthic-pelagic energy pathways.

A Review on Polychlorinated Biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) in South Asia with a Focus on Malaysia.

Science.gov (United States)

Kaw, Han Yeong; Kannan, Narayanan

Malaysia is a developing country in Southeast Asia, with rapid industrial and economic growth. Speedy population growth and aggressive consumerism in the past five decades have resulted in environmental pollution issues, including products containing polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). PCBs and PBDEs are classified as persistent organic pollutants (POPs) by the Stockholm Convention due to their persistence, bioaccumulation in the environment and toxicity to humans and wildlife. These compounds are known to cause liver dysfunction, thyroid toxicity, developmental neuro-toxicity and possibly cancer. PCBs in air, mussels, pellets, seawater, fresh water, and human breast milk samples were analyzed in Malaysia, while studies on the pollution level of PBDEs in Malaysia were conducted on mussels, soils, leachate and sediment samples. PCBs in breast milk collected from Malaysia was the highest among Asian developing countries, with mean concentration of 80 ng/g lipid weight. On the other hand, the mean concentration of PCBs in mussels collected from Malaysia recorded the second lowest, with 56 ng/g and 89 ng/g lipid weight in two studies respectively. The concentrations of PBDEs in mussels taken from Malaysia fall in the range of 0.84-16 ng/g lipid weight, which is considerably low compared to 104.5 ng/g lipid weight in Philippines and 90.59 ng/g in Korea. Nevertheless, there are limited studies on these compounds in Malaysia, particularly there is no research on PBDEs in breast milk and sediment samples. This review will summarize the contamination levels of PCBs and PBDEs in different samples collected from Asian countries since 1988 until 2010 with a focus on Malaysia and will provide needed information for further research in this field.

Polybrominated Diphenyl Ethers Orally Administration to Mice Were Tansferred to Offspring during Gestation and Lactation with Disruptions on the Immune System.

Science.gov (United States)

Hong, Soon Keun; Sohn, Kyung Hee; Kim, In Young; Lee, Jong Kwon; Ju, Jung Hun; Kim, Jin Ho; Lim, Chae Hyung; Han, Beom Seok; Jung, Hwa Chul; Lee, Jin Yong; Park, Kui Lea

2010-04-01

The present study was undertaken to examine the immunological effects of pentabrominated diphenyl ether (penta-BDE) and decabrominated diphenyl ether (deca-BDE) on the immune system of the dams and the developmental immune system of the offsprings. In this study, mated female C57BL/6J mice were orally administered penta-BDE, deca-BDE or corn oil for 5 weeks, from gestational day 6 to lactational day 21. The body weight of PND21 exposed to penta-BDE was significantly decreased relative to control mice, but that of post-natal day 63 (PND63) were recovered. Orally dosed dams with penta-BDE had significantly smaller absolute and relative spleen masses than control mice. Absolute and relative spleen and thymus masses of PND21 exposed to penta-BDE were significantly decreased over control. The exposure of dams and PND21 with penta-BDE reduced the number of splenocytes and thymocytes. As results of hematologic analysis, percentage WBC and percentage neutrophils increased in dams with deca-BDE. Splenic T cell proliferation in dams and PND21 exposed to penta-BDE was increased, and there were no significant difference in splenic B cell proliferation in all treatment groups. As results of flow cytometric analysis of splenocyte, percentage total T cell, Th cell and Tc cell in PND21 exposed to penta-BDE was slightly increased, and percentage macrophage in dams and PND21 exposed to deca-BDE was decreased. The ELISA results of antibody production show no significant difference in all treatment groups relative to controls. These results imply that PBDEs given to the dam were transferred to the offspring during gestation and lactation, and PBDEs transferred from the dam affect immune system of offspring.

Effect of polybrominated diphenyl ether congeners on placental cytokine production.

Science.gov (United States)

Arita, Yuko; Yeh, Corinne; Thoma, Theodosia; Getahun, Darios; Menon, Ramkumar; Peltier, Morgan R

2018-02-01

Polybrominated diphenyl ethers (PBDEs) are pollutants that may increase the risk of preterm birth. In previous studies, we found that a mixture of PBDEs altered the expression of biomarkers for preterm birth by the placenta. However, there are 209 different PBDE congeners with different tissue distributions. How these different congeners may alter the production of immunomodulators by the placenta that help to maintain the survival of the fetal allograft is unclear. Therefore, we compared the effects 5 common congeners on basal and bacteria-stimulated cytokine production by the placenta. Placental explant cultures were incubated with 20 μM of PBDE congeners 47, 99, 100, 153, 209 or vehicle in the presence and absence of Escherichia coli for 20 h. Conditioned medium was harvested and concentrations of IL-1β, TNF-α, IL-6, sgp130, HO-1, IL-10, BDNF, and 8-IsoP quantified. For unstimulated cultures, all congeners, except for PBDE-47, reduced the production of IL-1β and IL-6 production was enhanced by PBDE-153. BDNF concentrations tended to be reduced by most PBDE congeners and IL-10 production was enhanced by PBDE-99, -153, and -209. 8-IsoP production was enhanced by PBDE-153, but not the other congeners. For bacteria-stimulated cultures, PBDE-47 increased IL-1β production and PBDE-47, -153, and -209 tended to reduce TNF-α production. IL-6 production was enhanced by all PBDEs except 153. IL-10 production was enhanced by all congeners except for PBDE-47. All congeners significantly enhanced BDNF and 8-IsoP. These results suggest that PBDEs can alter the expression of placental biomarkers in a congener and infection-dependent manner. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular activation analysis for organo-halogen contaminants in yogurt

International Nuclear Information System (INIS)

Zhang Hong; Chai Zhifang

2004-01-01

The concentrations of total halogen (TX), extractable organo-halogen (EOX), extractable persistent organo-halogen (EPOX), organo-chlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in 18 different yogurt specimens of 14 brands from Beijing, Tianjin, Shanghai, Guangzhou and Shijiazhuang were determined by epithermal neutron activation analysis (ENAA), molecular activation analysis (MAA) and GC-Mass Spectrometry (GC-MS), respectively. The results indicated that the halogen in yogurt mainly existed as inorganic species and non-extractable organo-halogen compounds. About 1/3 to 1/4 of EOX was EPOX. Further, EOCl and EPOCl were the main organo-halogen species in yogurt. The average concentration of the unknown organo-chlorine was 96% of the EPOCl. HCHs and DDTs were still the main contaminants of OCPs in the yogurt of interest. Also, PCB202, PCB103 and PCB208 were the main contaminants of PCBs. (authors)

Integrated analysis of halogenated organic pollutants in sub-millilitre volumes of venous and umbilical cord blood sera

Energy Technology Data Exchange (ETDEWEB)

Grimalt, Joan O.; Carrizo, Daniel; Otero, Raquel; Vizcaino, Esther [Institute of Environmental Assessment and Water Research (IDAeA-CSIC), Department of Environmental Chemistry, Barcelona, Catalonia (Spain); Howsam, Mike [Universite de Lille 2, Centre Universitaire de Mesure et d' Analyse, Faculte de Pharmacie, Lille (France); Rodrigues de Marchi, Mary Rosa [Institute of Chemistry UNESP, Department of Analytical Chemistry, Araraquara, SP (Brazil)

2010-03-15

A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs, polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD) and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000{mu}L were extracted and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction of small volumes ({>=}300 {mu}L) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability ranged from 0.1-14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n=73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned halogenated pollutants using this method and the results are briefly described. (orig.)

Antioxidant phenolic compounds isolated from wild Pyrus ussuriensis Maxim. fruit peels and leaves.

Science.gov (United States)

Qiu, Daren; Guo, Jie; Yu, Huimei; Yan, Jiao; Yang, Shengxiang; Li, Xiang; Zhang, Yamei; Sun, Jinzhu; Cong, Jie; He, Shuliang; Wei, Dongsheng; Qin, Jian-Chun

2018-02-15

Thirteen phenolic compounds were isolated from pear (Pyrus ussuriensis Maxim.) peels and leaves extracts by using various column chromatography techniques with a guided DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging assay, the result of antioxidant activity of phenolic compounds is then verified by measurement of ROS (reactive oxygen species). The isolated compounds were identified as rutin (1), (-)-catechin (2), orobol (3), daidzein (4), tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether (5), tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl-9″-O-acetyl)-glyceryl] ether (6), 5,7,3',5'-tetrahydroxyflavanone (7), artselaeroside A (8), trilobatin (9), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (10), quercetin-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (11), apigenin (12) and quercetin (13) on the basis of nuclear magnetic resonance spectroscopy along with comparison with literature data. Among these compounds, quercetin and quercetin-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside exhibited potent DPPH radical-scavenging activity with IC 50 (Half Maximal Inhibitory Concentration) value of 6.06 and 9.60μg/mL, respectively. The results revealed that P. ussuriensis could be used in the fields of food and medicine to prevent human aging diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimation of the source strength of polybrominated diphenyl ethers based on their diel variability in air in Zurich, Switzerland.

Science.gov (United States)

Moeckel, Claudia; Gasic, Bojan; MacLeod, Matthew; Scheringer, Martin; Jones, Kevin C; Hungerbühler, Konrad

2010-06-01

Diel (24-h) concentration variations of polybrominated diphenyl ethers (PBDEs) in air were measured in the center of Zurich, Switzerland, and on Uetliberg, a hill about 5 km from the city center. Air samples were collected simultaneously at both sites over 4 h time periods for 3 consecutive days during a stable high pressure system in August 2007. Higher PBDE concentrations in the city compared to the Uetliberg site indicate that Zurich is a likely source of PBDEs to the atmosphere. A multimedia mass balance model was used to (i) explain the diel cycling pattern of PBDE concentrations observed at both sites in terms of dominant processes and (ii) estimate emission rates of PBDEs from the city to the atmosphere. We estimate that Zurich emits 0.4, 6.2, 1.6, and 0.4 kg year(-1) of the PBDE congeners 28, 47, 99, and 100, respectively. On a per-capita basis, these estimates are within the range or somewhat above those obtained in other studies using approaches based on emission factors (EF) and PBDE production, usage, and disposal data, or concentration measurements. The present approach complements emission estimates based on the EF approach and can also be applied to source areas where EFs and PBDE material flows are poorly characterized or unknown, such as electronic waste processing plants.

The environmental fate of polybrominated diphenyl ethers in the centre of Stockholm - Assessment using a multimedia fugacity model

Energy Technology Data Exchange (ETDEWEB)

Palm, Anna

2001-01-01

A local-scale assessment of the environmental fate of three congeners of polybrominated diphenyl ethers (PBDEs) has been performed for the centre of Stockholm. The partitioning properties and main transport processes of these congeners in Stockholm are identified using a site-specific multimedia fugacity model, called CeStoc, that was developed and parameterized for the area of interest. CeStoc was based on level III and IV fugacity models. Five compartments were included: air, water, soil, sediment and an organic film covering the impervious surfaces in the city. The model was satisfactory calibrated with the PAH fluoranthene, before it was run for the compounds of interest. Validation with environmental levels of PBDEs was made where possible, showing reasonable agreement with model results. According to the CeStoc results, the majority of the PBDEs emitted are transported out of the region through air advection, implying that Stockholm may act as a source for chemical release to other regions. The largest sink for PBDEs in Stockholm is soil, closely followed by sediment, the two compartments together accounting for about 98 % of the total amount remaining in the system. The degree of bromination does not seem to have a large impact on the environmental distribution in this area, but further research on e.g. physical-chemical properties is necessary before this can be finally concluded. Predicted concentrations of individual PBDE congeners in sediment and water lie in the same range as measured levels of individual PCB-congeners, indicating that PBDEs could have an environmental impact of about the same size as the PCBs.

Widespread polybrominated diphenyl ether (PBDE) contamination of urban soils in Melbourne, Australia.

Science.gov (United States)

McGrath, Thomas J; Morrison, Paul D; Sandiford, Christopher J; Ball, Andrew S; Clarke, Bradley O

2016-12-01

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in a variety of materials and products. PBDEs have been shown to accumulate in the environment and human populations while exhibiting a range of toxic effects. In this study, surface soil samples from 30 sites in the city of Melbourne, Australia, were analysed for PBDEs. Eight congeners of environmental concern (BDE-28, -47, -99, -100, -153, -154 -183 and -209) were assessed using selective pressurized liquid extraction (S-PLE) and gas chromatography coupled to triple quadrupole mass spectrometry (GC-MS/MS). PBDEs were detected in 29/30 samples with Σ 8 PBDE soil concentrations ranging nd-13,200 ng/g dw and Σ 7 PBDEs (excluding BDE-209) levels of nd-70.5 ng/g dw. Soils from waste disposal sites (n = 6) contained the highest median Σ 7 PBDE and Σ 8 PBDE concentrations, followed by manufacturing sites (n = 18) and then non-source sites (n = 6). Electronics recycling facilities contained the greatest levels of Σ 8 PBDEs by a significant margin (p production, with the most significant congener correlation existing between BDE-47 and BDE-99 (p < 0.001, r = 0.943). This first assessment of PBDEs in Melbourne soils indicates widespread contamination of the urban environment, including locations where direct sources to soil are not clear. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temporal variations of perfluoroalkyl substances and polybrominated diphenyl ethers in alpine snow

International Nuclear Information System (INIS)

Kirchgeorg, Torben; Dreyer, Annekatrin; Gabrieli, Jacopo; Kehrwald, Natalie; Sigl, Michael; Schwikowski, Margit

2013-01-01

The occurrence and temporal variation of 18 perfluoroalkyl substances (PFASs) and 8 polybrominated diphenyl ethers (PBDEs) in the European Alps was investigated in a 10 m shallow firn core from Colle Gnifetti in the Monte Rosa Massif (4455 m above sea level). The firn core encompasses the years 1997–2007. Firn core sections were analyzed by liquid chromatography–tandem mass spectrometry (PFASs) and gas chromatography–mass spectrometry (PBDEs). We detected 12 PFASs and 8 PBDEs in the firn samples. Perfluorobutanoic acid (PFBA; 0.3–1.8 ng L −1 ) and perfluorooctanoic acid (PFOA; 0.2–0.6 ng L −1 ) were the major PFASs while BDE 99 ( −1 ) and BDE 47 (n.d.–2.6 ng L −1 ) were the major PBDEs. This study demonstrates the occurrence of PFASs and PBDEs in the European Alps and provides the first evidence that PFASs compositions may be changing to PFBA-dominated compositions. -- Highlights: •PFASs and PBDEs were detected in low ng L −1 concentrations in an Alpine firn core. •BDE 47, BDE 99 and BDE 209 are the dominating PBDEs. •PFOA, PFNA and PFBA are the major PFASs. •We demonstrate a change in the PFASs composition. •Atmospheric degradation of volatile precursor might be the main source for >C8 PFCAs. -- PFAS and PBDE concentrations in European Alpine snow provide information about the occurrence, accumulation and recent changes of these persistent organic pollutants in Alpine regions

Dietary intake estimations of polybrominated diphenyl ethers (PBDEs) based on a total diet study in Osaka, Japan.

Science.gov (United States)

Akutsu, K; Takatori, S; Nakazawa, H; Hayakawa, K; Izumi, S; Makino, T

2008-01-01

This study presents the results of a total diet study performed for estimating the dietary intake of polybrominated diphenyl ethers (PBDEs) in Osaka, Japan. The concentrations of 36 PBDEs were measured in samples from 14 food groups (Groups I-XIV). PBDEs were detected only in Groups IV (oils and fats), V (legumes and their products), X (fish, shellfish, and their products), and XI (meat and eggs) at concentrations of 1.8, 0.03, 0.48, and 0.01 ng g⁻¹, respectively. For an average person, the lower bound dietary intakes of penta- and deca-formulations were estimated to be 46 and 21 ng day⁻¹, respectively. A high proportion of the decabrominated congener (DeBDE-209) was observed in Group IV. To confirm the presence of DeBDE-209 in vegetable oils, an additional analysis was performed using 18 vegetable oil samples. Of these, seven contained ng g⁻¹ levels of DeBDE-209.

Vertical distribution of dehalogenating bacteria in mangrove sediment and their potential to remove polybrominated diphenyl ether contamination.

Science.gov (United States)

Pan, Ying; Chen, Juan; Zhou, Haichao; Farzana, Shazia; Tam, Nora F Y

2017-11-30

The removal and degradation of polybrominated diphenyl ethers (PBDEs) in sediments are not clear. The vertical distribution of total and dehalogenating bacteria in sediment cores collected from a typical mangrove swamp in South China and their intrinsic degradation potential were investigated. These bacterial groups had the highest abundances in surface sediments (0-5cm). A 5-months microcosm experiment also showed that surface sediments had the highest rate to remove BDE-47 than deeper sediments (5-30cm) under anaerobic condition. The deeper sediments, being more anaerobic, had lower population of dehalogenating bacteria leading to a weaker BDE-47 removal potential than surface sediments. Stepwise multiple regression analysis indicated that Dehalococcoides spp. were the most important dehalogenating bacteria affecting the anaerobic removal of BDE-47 in mangrove sediments. This is the first study reporting that mangrove sediments harbored diverse groups of dehalogenating bacteria and had intrinsic potential to remove PBDE contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

An enantioselective synthesis of S-γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3-14C] hydrochloride, an important metabolite of fluoxetine hydrochloride

International Nuclear Information System (INIS)

Wheeler, W.J.

1992-01-01

The S-enantiomer of γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3- 14 C] hydrochloride has been prepared in eight steps from acetophenone-[carbonyl- 14 C]. The key step in the synthesis involved the enantioselective reduction of R-2-chloroacetophenone-[1- 14 C]with (-)-diisopinocampheyl-chloroborane in an 86.5% yield. The chlorohydrin was converted to R-phenyloxirane-[1- 14 C], which was subsequently converted to the corresponding R-cyanohydrin by reaction with TMS-CN/CaO. Borane reduction and arylation, followed by salt formation yielded S-γ-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3- 14 C] hydrochloride. (author)

Biosensor discovery of thyroxine transport disrupting chemicals

International Nuclear Information System (INIS)

Marchesini, Gerardo R.; Meimaridou, Anastasia; Haasnoot, Willem; Meulenberg, Eline; Albertus, Faywell; Mizuguchi, Mineyuki; Takeuchi, Makoto; Irth, Hubertus; Murk, Albertinka J.

2008-01-01

Ubiquitous chemicals may interfere with the thyroid system that is essential in the development and physiology of vertebrates. We applied a surface plasmon resonance (SPR) biosensor-based screening method for the fast screening of chemicals with thyroxine (T4) transport disrupting activity. Two inhibition assays using the main thyroid hormone transport proteins, T4 binding globulin (TBG) and transthyretin (TTR), in combination with a T4-coated biosensor chip were optimized and automated for screening chemical libraries. The transport protein-based biosensor assays were rapid, high throughput and bioeffect-related. A library of 62 chemicals including the natural hormones, polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs) and metabolites, halogenated bisphenol A (BPA), halogenated phenols, pharmaceuticals, pesticides and other potential environmentally relevant chemicals was tested with the two assays. We discovered ten new active compounds with moderate to high affinity for TBG with the TBG assay. Strikingly, the most potent binding was observed with hydroxylated metabolites of the brominated diphenyl ethers (BDEs) BDE 47, BDE 49 and BDE 99, that are commonly found in human plasma. The TTR assay confirmed the activity of previously identified hydroxylated metabolites of PCBs and PBDEs, halogenated BPA and genistein. These results show that the hydroxylated metabolites of the ubiquitous PBDEs not only target the T4 transport at the TTR level, but also, and to a great extent, at the TBG level where most of the T4 in humans is circulating. The optimized SPR biosensor-based transport protein assay is a suitable method for high throughput screening of large libraries for potential thyroid hormone disrupting compounds

Biosensor discovery of thyroxine transport disrupting chemicals.

Science.gov (United States)

Marchesini, Gerardo R; Meimaridou, Anastasia; Haasnoot, Willem; Meulenberg, Eline; Albertus, Faywell; Mizuguchi, Mineyuki; Takeuchi, Makoto; Irth, Hubertus; Murk, Albertinka J

2008-10-01

Ubiquitous chemicals may interfere with the thyroid system that is essential in the development and physiology of vertebrates. We applied a surface plasmon resonance (SPR) biosensor-based screening method for the fast screening of chemicals with thyroxine (T4) transport disrupting activity. Two inhibition assays using the main thyroid hormone transport proteins, T4 binding globulin (TBG) and transthyretin (TTR), in combination with a T4-coated biosensor chip were optimized and automated for screening chemical libraries. The transport protein-based biosensor assays were rapid, high throughput and bioeffect-related. A library of 62 chemicals including the natural hormones, polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs) and metabolites, halogenated bisphenol A (BPA), halogenated phenols, pharmaceuticals, pesticides and other potential environmentally relevant chemicals was tested with the two assays. We discovered ten new active compounds with moderate to high affinity for TBG with the TBG assay. Strikingly, the most potent binding was observed with hydroxylated metabolites of the brominated diphenyl ethers (BDEs) BDE 47, BDE 49 and BDE 99, that are commonly found in human plasma. The TTR assay confirmed the activity of previously identified hydroxylated metabolites of PCBs and PBDEs, halogenated BPA and genistein. These results show that the hydroxylated metabolites of the ubiquitous PBDEs not only target the T4 transport at the TTR level, but also, and to a great extent, at the TBG level where most of the T4 in humans is circulating. The optimized SPR biosensor-based transport protein assay is a suitable method for high throughput screening of large libraries for potential thyroid hormone disrupting compounds.

[Indoor dust as a pathway of human exposure to polybrominated diphenyl ethers (PBDEs)].

Science.gov (United States)

Góralczyk, Katarzyna; Struciński, Paweł; Hernik, Agnieszka; Czaja, Katarzyna; Korcz, Wojciech; Minorczyk, Maria; Ludwicki, Jan K

2012-01-01

The brominated diphenyl ethers (PBDEs) belong to a class of synthetic, additive brominated flame retardants (BFRs). PBDEs are used to reduce the flammability of commercial and household products such as textiles, various plastic polymers, furnishing foam, and electronic equipment. People spend a large percentage of their life-time indoors at home, in offices and cars, etc, providing many opportunities for lengthy exposure to PBDEs from residential settings and commercial products in an indoor environment. In recent time, the foodstuffs, mainly food of animal origin, have been indicated as the main pathway of human exposure to PBDEs. However, many studies have shown that the indoor environment, mainly indoor dust, can be also a significant source of exposure to PBDEs, especially for younger children (toddlers) because of their behavioral patterns, eg. putting fingers, toys, and other items in their mouth. Numerous studies show that the median intakes of PBDEs via dust for adult range from 1.41 to 277 ng x day(-1) is lower than that via food which range from 135 to 333 ng x day-', while the median intake of these compounds via indoor dust for children range from 101 to 404 ng x day(-1) is much higher than via food: 77-190 ng x day(-1). The congener pattern observed in the indoor dust is different to that found in food. The indoor dust is dominated by the congener BDE-209 vs. food where the most dominated congeners are BDE-47 and BDE-99. Human exposure to PBDEs and other brominated flame retardants (BFRs) is widely widespread throughout the world and it depends on a country range of usage, production and legislation concerning these chemicals as well as a citizen's behavior. Generally, human exposure has been found higher in North America than in Europe and Asia. Within European countries the significant highest concentrations in dust have been found in the United Kingdom. It should be noted that many uncertainty factors such as personal habits, dietary preferences

BDE99 (2,2',4,4',5-pentabromodiphenyl ether) suppresses differentiation into neurotransmitter phenotypes in PC12 cells.

Science.gov (United States)

Slotkin, Theodore A; Card, Jennifer; Infante, Alice; Seidler, Frederic J

2013-01-01

Early-life exposures to brominated diphenyl ethers (BDEs) lead to neurobehavioral abnormalities later in life. Although these agents are thyroid disruptors, it is not clear whether this mechanism alone accounts for the adverse effects. We evaluated the impact of 2,2',4,4',5-pentabromodiphenyl ether (BDE99) on PC12 cells undergoing neurodifferentiation, contrasting the effects with chlorpyrifos, a known developmental neurotoxicant. BDE99 elicited decrements in the number of cells, evidenced by a reduction in DNA levels, to a lesser extent than did chlorpyrifos. This did not reflect cytotoxicity from oxidative stress, since cell enlargement, monitored by the total protein/DNA ratio, was not only unimpaired by BDE99, but was actually enhanced. Importantly, BDE99 impaired neurodifferentiation into both the dopamine and acetylcholine neurotransmitter phenotypes. The cholinergic phenotype was affected to a greater extent, so that neurotransmitter fate was diverted away from acetylcholine and toward dopamine. Chlorpyrifos produced the same imbalance, but through a different underlying mechanism, promoting dopaminergic development at the expense of cholinergic development. In our earlier work, we did not find these effects with BDE47, a BDE that has greater endocrine disrupting and cytotoxic effects than BDE99. Thus, our results point to interference with neurodifferentiation by specific BDE congeners, distinct from cytotoxic or endocrine mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

Asymmetric Diels-Alder Reaction of α-Substituted and β,β-Disubstituted α,β-Enals via Diarylprolinol Silyl Ether for the Construction of All-Carbon Quaternary Stereocenters.

Science.gov (United States)

Hayashi, Yujiro; Bondzic, Bojan P; Yamazaki, Tatsuya; Gupta, Yogesh; Ogasawara, Shin; Taniguchi, Tohru; Monde, Kenji

2016-10-24

The asymmetric Diels-Alder reaction of α-substituted acrolein proceeds in the presence of the trifluoroacetic acid salt of trifluoromethyl-substituted diarylprolinol silyl ether to afford the exo-isomer with both excellent diastereoselectivity and high enantioselectivity. In the Diels-Alder reaction of a β,β-disubstituted α,β-unsaturated aldehyde, good exo-selectivity and excellent enantioselectivity was obtained when the perchloric acid salt of the bulky triisopropyl silyl ether of trifluoromethyl substituted diarylprolinol was employed as an organocatalyst in the presence of water. In both cases, all-carbon quaternary stereocenters are constructed enantioselectively. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Levels of dechloranes and polybrominated diphenyl ethers (PBDEs) in human serum from France.

Science.gov (United States)

Brasseur, Catherine; Pirard, Catherine; Scholl, Georges; De Pauw, Edwin; Viel, Jean-François; Shen, Li; Reiner, Eric J; Focant, Jean-François

2014-04-01

Human exposure to dechloranes has been evaluated in Western Europe (France) with the analysis of Dechlorane Plus (DP), Dechloranes (Dec) 602, 603 and 604, Chlordene Plus (CP) and Mirex in 48 serum samples collected between 2003 and 2005. While no production source has been identified in Europe until now, detection frequencies for all investigated dechloranes were high, except for Dec 604 which was below detection limit for all samples. The mean DP concentration was 1.40±1.40ng/g lipid weight (lw), lower than levels reported in serum from Chinese population, but higher than levels reported in Canadian human milk. To the best of our knowledge, this is the first time that ∑5dechlorane levels are reported for human serum. A specific pattern of contamination was found (Dec 603>DP>Mirex>Dec 602>CP) compared to other biota samples that have been analyzed from Europe, with Dec 603 as the most abundant dechlorane (mean level: 2.61±2.63ng/g lw). Dec 603 and CP levels were correlated with age and with levels of some bioaccumulative organochlorine pesticides (OCPs). These results indicate that bioaccumulation properties should be further investigated and taken in consideration when assessing human exposure to dechloranes. For comparison purposes, polybrominated diphenyl ether (PBDE) levels were also measured for BDE-47, -99, -100, -153 and -154 in the serum samples. As expected, BDE-47 and BDE-153 were the major congeners with mean levels of 2.06±1.80ng/g lw and 1.39±0.97ng/g lw, respectively. The mean ∑5PBDE levels (4.32±2.99ng/g lw) were in the range typical of Western Europe levels, but lower than the mean ∑5dechlorane levels (6.24±4.16ng/g lw). These results indicate that the attention to dechloranes should be continued if research indicates toxicological concerns. Copyright © 2013 Elsevier Ltd. All rights reserved.

Riverine inputs of polybrominated diphenyl ethers from the Pearl River Delta (China) to the coastal ocean.

Science.gov (United States)

Guan, Yu-Feng; Wang, Ji-Zhong; Ni, Hong-Gang; Luo, Xiao-Jun; Mai, Bi-Xian; Zeng, Eddy Y

2007-09-01

Riverine runoff is an important mode to transport anthropogenic pollutants from terrestrial sources to oceans. Polybrominated diphenyl ethers (PBDEs) were measured in riverine runoff samples from the eight major outlets within the Pearl River Delta (PRD), China, an economically fast developing region housing a vast number of electronics manufacturing and assembling plants. The sigma 17PBDEs (sum of 17 BDE congeners, i.e., BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, -183, -196, -197, -203, -206, -207, -208, and -209) concentrations varied from 344 to 68,000 pg/L, with those of BDE-209, BDE-47, and BDE-99 being 335-65200, 3-143, and production of brominated fire retardants (approximately 10000 metric tons/year) and the annual riverine input of total PBDEs from the PRD, suggesting that the majority of PBDEs inventory has been accumulated from importation of e-wastes. Because of the continuous importation of e-wastes and strong demand for brominated fire retardants, the impact of PBDEs on China's and the world's environments is expected to persist for many years to come.

Disruption of type 2 iodothyronine deiodinase activity in cultured human glial cells by polybrominated diphenyl ethers.

Science.gov (United States)

Roberts, Simon C; Bianco, Antonio C; Stapleton, Heather M

2015-06-15

Polybrominated diphenyl ether (PBDE) flame retardants are endocrine disruptors and suspected neurodevelopmental toxicants. While the direct mechanisms of neurodevelopmental toxicity have not been fully elucidated, it is conceivable that alterations in thyroid hormone levels in the developing brain may contribute to these effects. Cells within the brain locally convert thyroxine (T4) to the biologically active triiodothyronine (T3) through the action of the selenodeiodinase type 2 iodothyronine deiodinase (DIO2). Previous studies have demonstrated that PBDEs can alter hepatic deiodinase activity both in vitro and in vivo; however, the effects of PBDEs on the deiodinase isoforms expressed in the brain are not well understood. Here, we studied the effects of several individual PBDEs and hydroxylated metabolites (OH-BDEs) on DIO2 activity in astrocytes, a specialized glial cell responsible for production of more than 50% of the T3 required by the brain. Primary human astrocytes and H4 glioma cells were exposed to individual PBDEs or OH-BDEs at concentrations up to 5 μM. BDE-99 decreased DIO2 activity by 50% in primary astrocyte cells and by up to 80% in the H4 cells at doses of ≥500 nM. 3-OH-BDE-47, 6-OH-BDE-47, and 5'-OH-BDE-99 also decreased DIO2 activity in cultured H4 glioma cells by 45-80% at doses of approximately 1-5 μM. Multiple mechanisms appear to contribute to the decreased DIO2 activity, including weakened expression of DIO2 mRNA, competitive inhibition of DIO2, and enhanced post-translational degradation of DIO2. We conclude that decreases in DIO2 activity caused by exposure to PBDEs may play a role in the neurodevelopmental deficits caused by these toxicants.

Polybrominated diphenyl ethers (PBDEs) in indoor and outdoor window organic films in Izmir, Turkey

International Nuclear Information System (INIS)

Cetin, Banu; Odabasi, Mustafa

2011-01-01

Polybrominated diphenyl ether (PBDE) concentrations of outdoor and indoor organic films on window glasses were measured at different locations (offices, laboratories, and homes in urban, suburban, rural, and industrial sites) in Izmir, Turkey. Σ 7 PBDE concentrations were dominated by technical penta and deca-BDE mixture components. Average total outdoor PBDE (Σ 7 PBDE) concentrations for suburban, urban, and industrial sites were 43.5, 45.5, and 206 ng m -2 , respectively. This spatial gradient (industrial > urban > suburban concentrations) was similar to one observed for ambient air concentrations recently in Izmir, Turkey. The highest concentrations measured in the industrial area were attributed to the significant PBDE emissions from several steel plants located in the area. Air-organic film partitioning modeling results have suggested that organic films can be used in conjunction with the dynamic uptake model to approximate the gas-phase ambient air concentrations. Modeling results have also indicated that congeners in the gas-phase with very large octanol-air partition coefficients (i.e., BDE-154, -153, and -209) will require several months to approach equilibrium with the surface films. This finding may have important implications for gas-particle and gas-film partitioning, transport, and photolytic degradation of atmospheric PBDEs.

Sedimentary records of hydroxylated and methoxylated polybrominated diphenyl ethers in the southern Yellow Sea.

Science.gov (United States)

Fan, Ying; Lan, Jing; Zhao, Zongshan; Zhao, Meixun

2014-07-15

Although hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have caused much concern in recent years, few reports had discussed on their input history. In this study, we measured the contents of nine MeO-BDEs, ten OH-BDEs, and total organic carbon (TOC) of two sediment cores from the southern Yellow Sea. 6-MeO-BDE-47, 2'-MeO-BDE-68, 6-OH-BDE-47, and 2'-OH-BDE-68 were the predominant congeners in HH12, while only 2'-OH-BDE-68 and 6-OH-BDE-47 were frequently detected in core HH11. The records showed that OH-/MeO-BDEs in both cores had increased rapidly since the 1950s. Their existence was detected at the bottom layers (∼1800 s) prior to the production of PBDEs (1960s), thus OH-/MeO-BDEs originate from natural origins rather than artificial PBDEs. Comparisons between TOC and OH-/MeO-BDEs indicated that TOC is a potential factor affecting the accumulation of OH-/MeO-BDEs in marine environments. Similar trends and significant correlations between OH-BDEs and MeO-BDEs suggest their common origins or interconversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Polybrominated diphenyl ethers (PBDEs) in indoor and outdoor window organic films in Izmir, Turkey

Energy Technology Data Exchange (ETDEWEB)

Cetin, Banu [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Kaynaklar Campus, 35160 Buca, Izmir (Turkey); Odabasi, Mustafa, E-mail: mustafa.odabasi@deu.edu.tr [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Kaynaklar Campus, 35160 Buca, Izmir (Turkey)

2011-01-30

Polybrominated diphenyl ether (PBDE) concentrations of outdoor and indoor organic films on window glasses were measured at different locations (offices, laboratories, and homes in urban, suburban, rural, and industrial sites) in Izmir, Turkey. {Sigma}{sub 7}PBDE concentrations were dominated by technical penta and deca-BDE mixture components. Average total outdoor PBDE ({Sigma}{sub 7}PBDE) concentrations for suburban, urban, and industrial sites were 43.5, 45.5, and 206 ng m{sup -2}, respectively. This spatial gradient (industrial > urban > suburban concentrations) was similar to one observed for ambient air concentrations recently in Izmir, Turkey. The highest concentrations measured in the industrial area were attributed to the significant PBDE emissions from several steel plants located in the area. Air-organic film partitioning modeling results have suggested that organic films can be used in conjunction with the dynamic uptake model to approximate the gas-phase ambient air concentrations. Modeling results have also indicated that congeners in the gas-phase with very large octanol-air partition coefficients (i.e., BDE-154, -153, and -209) will require several months to approach equilibrium with the surface films. This finding may have important implications for gas-particle and gas-film partitioning, transport, and photolytic degradation of atmospheric PBDEs.

The flame retardant DE-71 (a mixture of polybrominated diphenyl ethers) inhibits human differentiated thyroid cell function in vitro

DEFF Research Database (Denmark)

Kronborg, Thit Mynster; Hansen, Juliana Frohnert; Rasmussen, Åse Krogh

2017-01-01

Normal thyroid function is essential for general growth and metabolism, but can be affected by endocrine disrupting chemicals (EDCs). Polybrominated diphenyl ethers (PBDEs) have been used worldwide to reduce flammability in different materials and are suspected to be EDCs. The production...... of the commercial Penta- and OctaBDE mixtures is banned, but DecaBDEs and existing products may leak PBDEs into the environment. Our aim was to investigate the effect of the PentaBDE mixture DE-71 on human thyroid cells in vitro. Primary human thyroid cells were obtained as paraadenomatous tissue and cultured...... in monolayers. The influence of DE-71 on cyclic adenosine monophosphate (cAMP) and thyroglobulin (Tg) production was examined in the culture medium by competitive radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Real-time quantitative PCR analysis of thyroid-specific genes was performed...

Phosphorylated lignin as a halogen-free flame retardant additive for epoxy composites

Science.gov (United States)

Gamini P. Mendis; Sydney G. Weiss; Matthew Korey; Charles R. Boardman; Mark Dietenberger; Jeffrey P. Youngblood; John A. Howarter

2016-01-01

Sustainable, non-halogenated flame retardants are desired for a variety of industry applications. Lignin, as an industrially processed wood derivative, has been examined as a potential sustainable flame retardant additive to polymer systems. Here, the lignin is phosphorylated using a pyridine-catalysed esterification reaction with diphenyl phosphoryl chloride to...

Elevated Serum Polybrominated Diphenyl Ethers and Alteration of Thyroid Hormones in Children from Guiyu, China

Science.gov (United States)

Xu, Xijin; Liu, Junxiao; Zeng, Xiang; Lu, Fangfang; Chen, Aimin; Huo, Xia

2014-01-01

Informal electronic waste (e-waste) recycling results in serious environmental pollution of polybrominated diphenyl ethers (PBDEs) and heavy metals. This study explored whether there is an association between PBDEs, heavy metal and key growth- and development-related hormones in children from Guiyu, an e-waste area in southern China. We quantified eight PBDE congeners using gas chromatographic mass spectrometry, lead and cadmium utilizing graphite furnace atomic absorption spectrometry, three thyroids with radioimmunoassay and two types of growth hormones by an enzyme-linked immune-sorbent assay (ELISA) in 162 children, 4 to 6 years old, from Guiyu. In blood, median total PBDE was 189.99 ng/g lipid. Lead and cadmium concentrations in blood averaged 14.53±4.85 µg dL−1 and 0.77±0.35 µg L−1, respectively. Spearman partial correlation analysis illustrated that lead was positively correlated with BDE153 and BDE183. Thyroid-stimulating hormone (TSH) was positively correlated with almost all PBDE congeners and negatively correlated with insulin-like growth factor binding protein-3 (IGFBP-3), whereas free triiodothyronine (FT3) and free thyroxine (FT4) were negatively correlated with BDE154. However, no correlation between the hormones and blood lead or cadmium levels was found in this study. Adjusted multiple linear regression analysis showed that total PBDEs was negatively associated with FT3 and positively associated with TSH. Notably, FT4 was positively correlated with FT3, house functions as a workshop, and father's work involved in e-waste recycling and negatively correlated with vitamin consumptions. TSH was negatively related with FT4, paternal residence time in Guiyu, working hours of mother, and child bean products intake. IGFBP-3 was positively correlated with IGF-1 and house close to an e-waste dump. These results suggest that elevated PBDEs and heavy metals related to e-waste in Guiyu may be important risk factors for hormone alterations in children

Fate, partitioning, and mass loading of polybrominated diphenyl ethers (PBDEs) during the treatment processing of municipal sewage.

Science.gov (United States)

Song, Min; Chu, Shaogang; Letcher, Robert J; Seth, Rajesh

2006-10-15

Sewage treatment plant (STP) effluents are likely a major source of contamination for PBDEs, especially in the receiving water bodies of local aquatic environments surrounding the location of these discharges. Congeners of the pentaBDE mixture, 2,2,',4,4'-tetrabromodiphenyl ether (BDE47), 2,2,',4,4',5-pentabromodiphenyl ether (BDE99), 2,2,',4,4',6-pentabromodiphenyl ether (BDE100), 2,2,',4,4',5,5'-hexabromodiphenyl ether (BDE153), and 2,2,',4,4',5,6'-hexabromodiphenyl ether (BDE154), are of great environmental concern in North America due to their persistence, potential for bioaccumulation, and >97% use of the global production of the mixture in the region. Detailed characterization of the distribution of eight PBDE congeners (2,4,4'-tribromoDE (BDE28) and BDE47, 99, 100, 138, 153, 154, and 183) was carried out at five sites along the treatment process at an activated sludge-type secondary treatment municipal STP facility. PentaBDE mixture congeners, sigma5PBDE (sum of BDE47, 99, 100, 153, and 154) accounted for >98% of the total (sigma 8) PBDE concentration at all sites, with over 80% of the composition being BDE47 and BDE99. Presence of dissolved organic matter affected the mobility of PBDEs during the initial stages of the treatment process. About 9% of the influent mass of sigma5PBDE to the facility is estimated to be discharged into the Little River (leading to the Detroit River) with the final effluent, resulting in an estimated mass loading of approximately 0.7 kg/year. The total mass loading of sigma5PBDE to the Detroit River is expected to be much larger as effluent from this facility accounts for <10% of the total STP discharges to the river.

Gas-liquid partitioning of halogenated volatile organic compounds in aqueous cyclodextrin solutions

Energy Technology Data Exchange (ETDEWEB)

Ondo, Daniel; Barankova, Eva [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dohnal, Vladimir, E-mail: dohnalv@vscht.cz [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic)

2011-08-15

Highlights: > Binding of halogenated VOCs with cyclodextrins examined through g-l partitioning. > Complex stabilities reflect host-guest size matching and hydrophobic interaction. > Presence of halogens in the guest molecule stabilizes the binding. > Thermodynamic origin of the binding varies greatly among the systems studied. > Results obey the guest-CD global enthalpy-entropy compensation relationship. - Abstract: Gas-liquid partitioning coefficients (K{sub GL}) were measured for halogenated volatile organic compounds (VOCs), namely 1-chlorobutane, methoxyflurane, pentafluoropropan-1-ol, heptafluorobutan-1-ol, {alpha},{alpha},{alpha}-trifluorotoluene, and toluene in aqueous solutions of natural {alpha}-, {beta}-, and {gamma}-cyclodextrins (CDs) at temperatures from (273.35 to 326.35) K employing the techniques of headspace gas chromatography and inert gas stripping. The binding constants of the 1:1 inclusion complex formation between the VOCs and CDs were evaluated from the depression of the VOCs volatility as a function of CD concentration. The host-guest size matching and the hydrophobic interaction concept were used to rationalize the observed widely different affinity of the VOC-CD pairs to form the inclusion complex. The enthalpic and entropic component of the standard Gibbs free energy of complex formation as derived from the temperature dependence of the binding constant indicate the thermodynamic origin of the binding to vary greatly among the systems studied, but follow the global enthalpy-entropy compensation relationships reported previously in the literature.

Prenatal and postnatal polybrominated diphenyl ether exposure and visual spatial abilities in children

Energy Technology Data Exchange (ETDEWEB)

Vuong, Ann M. [Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Braun, Joseph M. [Department of Epidemiology, Brown University School of Public Health, Providence, RI (United States); Yolton, Kimberly [Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Xie, Changchun [Division of Biostatistics and Bioinformatics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Webster, Glenys M. [BC Children' s Hospital Research Institute, Simon Fraser University, Vancouver, British Columbia (Canada); Sjödin, Andreas [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Dietrich, Kim N. [Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Lanphear, Bruce P. [BC Children' s Hospital Research Institute, Simon Fraser University, Vancouver, British Columbia (Canada); Chen, Aimin, E-mail: aimin.chen@uc.edu [Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States)

2017-02-15

Polybrominated diphenyl ethers (PBDEs) are associated with impaired visual spatial abilities in toxicological studies, but no epidemiologic study has investigated PBDEs and visual spatial abilities in children. The Health Outcomes and Measures of the Environment Study, a prospective birth cohort (2003–2006, Cincinnati, OH), was used to examine prenatal and childhood PBDEs and visual spatial abilities in 199 children. PBDEs were measured at 16±3 weeks gestation and at 1, 2, 3, 5, and 8 years using gas chromatography/isotope dilution high-resolution mass spectrometry. We used the Virtual Morris Water Maze to measure visual spatial abilities at 8 years. In covariate-adjusted models, 10-fold increases in BDE-47, −99, and −100 at 5 years were associated with shorter completion times by 5.2 s (95% Confidence Interval [CI] −9.3, −1.1), 4.5 s (95% CI −8.1, −0.9), and 4.7 s (95% CI −9.0, −0.3), respectively. However, children with higher BDE-153 at 3 years had longer completion times (β=5.4 s, 95% CI −0.3, 11.1). Prenatal PBDEs were associated with improved visual spatial memory retention, with children spending a higher percentage of their search path in the correct quadrant. Child sex modified some associations between PBDEs and visual spatial learning. Longer path lengths were observed among males with increased BDE-47 at 2 and 3 years, while females had shorter paths. In conclusion, prenatal and postnatal BDE-28, −47, −99, and −100 at 5 and 8 years were associated with improved visual spatial abilities, whereas a pattern of impairments in visual spatial learning was noted with early childhood BDE-153 concentrations. - Highlights: • The VMWM test was used to assess visual spatial abilities in children at 8 years. • BDE-153 at 3 years was adversely associated with visual spatial learning. • BDE-47, −99, and −100 at 5 years was associated with better visual spatial learning. • Prenatal PBDEs were associated with improved visual

Prenatal and postnatal polybrominated diphenyl ether exposure and visual spatial abilities in children

International Nuclear Information System (INIS)

Vuong, Ann M.; Braun, Joseph M.; Yolton, Kimberly; Xie, Changchun; Webster, Glenys M.; Sjödin, Andreas; Dietrich, Kim N.; Lanphear, Bruce P.; Chen, Aimin

2017-01-01

Polybrominated diphenyl ethers (PBDEs) are associated with impaired visual spatial abilities in toxicological studies, but no epidemiologic study has investigated PBDEs and visual spatial abilities in children. The Health Outcomes and Measures of the Environment Study, a prospective birth cohort (2003–2006, Cincinnati, OH), was used to examine prenatal and childhood PBDEs and visual spatial abilities in 199 children. PBDEs were measured at 16±3 weeks gestation and at 1, 2, 3, 5, and 8 years using gas chromatography/isotope dilution high-resolution mass spectrometry. We used the Virtual Morris Water Maze to measure visual spatial abilities at 8 years. In covariate-adjusted models, 10-fold increases in BDE-47, −99, and −100 at 5 years were associated with shorter completion times by 5.2 s (95% Confidence Interval [CI] −9.3, −1.1), 4.5 s (95% CI −8.1, −0.9), and 4.7 s (95% CI −9.0, −0.3), respectively. However, children with higher BDE-153 at 3 years had longer completion times (β=5.4 s, 95% CI −0.3, 11.1). Prenatal PBDEs were associated with improved visual spatial memory retention, with children spending a higher percentage of their search path in the correct quadrant. Child sex modified some associations between PBDEs and visual spatial learning. Longer path lengths were observed among males with increased BDE-47 at 2 and 3 years, while females had shorter paths. In conclusion, prenatal and postnatal BDE-28, −47, −99, and −100 at 5 and 8 years were associated with improved visual spatial abilities, whereas a pattern of impairments in visual spatial learning was noted with early childhood BDE-153 concentrations. - Highlights: • The VMWM test was used to assess visual spatial abilities in children at 8 years. • BDE-153 at 3 years was adversely associated with visual spatial learning. • BDE-47, −99, and −100 at 5 years was associated with better visual spatial learning. • Prenatal PBDEs were associated with improved visual

Remediation of polybrominated diphenyl ethers in soil using Ni/Fe bimetallic nanoparticles: Influencing factors, kinetics and mechanism

International Nuclear Information System (INIS)

Xie, Yingying; Fang, Zhanqiang; Cheng, Wen; Tsang, Pokeung Eric; Zhao, Dongye

2014-01-01

Polybrominated diphenyl ethers (PBDEs) are commonly used as additive flame retardants in all kinds of electronic products. PBDEs are now ubiquitous in the environment, with soil as a major sink, especially in e-waste recycling sites. This study investigated the degradation of decabromodiphenyl ether (BDE209) in a spiked soil using Ni/Fe bimetallic nanoparticles. The results indicated that Ni/Fe bimetallic nanoparticles are able to degrade BDE209 in soil at ambient temperature and the removal efficiency can reach 72% when an initial pH of 5.6 and at a Ni/Fe dosage of 0.03 g/g. A declining trend in degradation was noticed with decreasing Ni loading and increasing of initial BDE209 concentration. The degradation products of BDE209 were analyzed by GC-MS, which showed that the degradation of BDE209 was a process of stepwise debromination from nBr to (n − 1)Br. And a possible debromination pathway was proposed. At last, the degradation process was analyzed as two-step mechanism, mass transfer and reaction. This current study shows the potential ability of Ni/Fe nanoparticles to be used for removal of PBDEs in contaminated soil. - Highlights: • Ni/Fe bimetallic nanoparticles could effectively degradate BDE209 in soil. • The effects of various factors on remediation of BDE209 in soil using Ni/Fe were considered. • The degradation of BDE209 was a process of stepwise debromination from nBr to (n − 1)Br. • A possible debromination pathway and mechanism about removal of BDE209 in soil were proposed

Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments

International Nuclear Information System (INIS)

Jia, Fang; Gan, Jay

2014-01-01

Polybrominated diphenyl ethers (PBDEs) are widely found in sediments, especially congeners from the penta-BDE formula. Due to their strong affinity for black carbon (BC), bioavailability of PBDEs may be decreased in BC-amended sediments. In this study, we used a matrix-SPME method to measure the freely dissolved concentration (C free ) of PBDEs as a parameter of their potential bioavailability and evaluated the differences among biochar, charcoal, and activated carbon. Activated carbon displayed a substantially greater sequestration capacity than biochar or charcoal. At 1% amendment rate in sediment with low organic carbon (OC) content (0.12%), C free of six PBDEs was reduced by 47.5–78.0%, 47.3–77.5%, and 94.1–98.3% with biochar, charcoal, and activated carbon, respectively, while the sequestration was more limited in sediment with high OC content (0.87%). Therefore, it is important to consider the type and properties of the BC and the sediment in BC-based remediation or mitigation. -- Highlights: • A matrix-SPME method was developed for measuring C free of PBDEs in sediment porewater. • Different black carbon types differed greatly in their ability to decrease C free of PBDEs in sediments. • Activated carbon was much more efficient in sequestering PBDEs than biochar or charcoal. • The effect of black carbon was more pronounced in sediment with lower indigenous OC content. -- Biochar, charcoal, and activated carbon have been compared for their efficacy in sequestering PBDEs in sediments by using a matrix-SPME method

Evaluation of modulators and electron-capture detectors for comprehensive two-dimensional GC of halogenated organic compounds

NARCIS (Netherlands)

Kristenson, E.M.; Korytar, P.; Danielsson, C.; Kallio, M.; Brandt, M.; Makela, J.; Vreuls, R.J.J.; Beens, J.; Brinkman, U.A.T.

2003-01-01

Different cryogenic and a heated GC×GC modulator(s) were evaluated and compared for the analysis of high-boiling halogenated compounds. The cryogenic modulators investigated were: (i) the longitudinally modulated cryogenic system; (ii) the liquid-nitrogen-cooled jet modulator (KT2001); (iii) a

Determination of beta-radiation in 14C-labelled biological samples by 2,5-diphenyl-1,3,4-oxadiazole

International Nuclear Information System (INIS)

Kiehl, B.; Neumann, R.; Beger, J.

1991-01-01

2,5-Diphenyl-1,3,4-oxadiazole (PPD) has been investigated for its suitability as a primary szintillator. This compound can be used together with the secondary szintillator POPOP in toluene solution for the measurement of low-energetic β-radiation in biological samples marked by 14 C. A convenient approach to laboratory syntheses is presented. (orig.) [de

Occurrence of halogenated flame retardants in sediment off an urbanized coastal zone: association with urbanization and industrialization.

Science.gov (United States)

Liu, Hui-Hui; Hu, Yuan-Jie; Luo, Pei; Bao, Lian-Jun; Qiu, Jian-Wen; Leung, Kenneth M Y; Zeng, Eddy Y

2014-01-01

To examine the impacts of urbanization and industrialization on the coastal environment, sediment samples were collected from an urbanized coastal zone (i.e., Daya Bay and Hong Kong waters of South China) and analyzed for 20 polybrominated diphenyl ethers (PBDEs) and 10 alternative halogenated flame retardants (AHFRs). The sum concentration of PBDEs was in the range of 1.7-55 (mean: 17) ng g(-1), suggesting a moderate pollution level compared to the global range. The higher fractions of AHFRs (i.e., TBB+TBPH, BTBPE and DBDPE) than those of legacy PBDEs (i.e., penta-BDE, octa-BDE and deca-BDE) corresponded with the phasing out of PBDEs and increasing demand for AHFRs. Heavy contamination occurred at the estuary of Dan'ao River flowing through the Daya Bay Economic Zone, home to a variety of petrochemicals and electronics manufacturing facilities. The concentrations of HFRs in surface sediments of Hong Kong were the highest in Victoria Harbor, which receives around 1.4 million tons of primarily treated sewage daily, and a good relationship (r(2) = 0.80; p 0.73; p < 0.05) with the production volume of electronic devices, production value of electronic industries and population size, demonstrating the importance of industrializing and urbanizing processes in dictating the historical input patterns of AHFRs.

Levels, profile and distribution of Dechloran Plus (DP) and Polybrominated Diphenyl Ethers (PBDEs) in the environment of Pakistan.

Science.gov (United States)

Syed, Jabir Hussain; Malik, Riffat Naseem; Li, Jun; Wang, Yan; Xu, Yue; Zhang, Gan; Jones, Kevin C

2013-11-01

No scientific data is available on emerging contaminants including Polybrominated Diphenyl Ethers (PBDEs) and Dechloran Plus (DP) levels in the environment in Pakistan. Levels of PBDEs and DP were determined in the soil, sediment and atmospheric samples along the stretch of River Ravi in Punjab Province. Average concentrations of ΣPBDEs in atmosphere, soils and sediments were 36 pg m(-3), 40 ng g(-1) and 640 ng g(-1). BDE-209 was the most abundant PBDE congener, showing that deca-BDE accounts for most of the total PBDE emitted in the environment of Pakistan. Total DP levels were calculated as 88 pg m(-3), 0.8 ng g(-1) and 1.9 ng g(-1) in air, soil and sediment samples, respectively. The lower average fractions of anti-DP showed significant differences to those of the technical mixtures, indicating the lack of DP production source in Pakistan. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterizing the sorption of polybrominated diphenyl ethers (PBDEs) to cotton and polyester fabrics under controlled conditions

Energy Technology Data Exchange (ETDEWEB)

Saini, Amandeep [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Rauert, Cassandra [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Simpson, Myrna J. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Harrad, Stuart [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Diamond, Miriam L., E-mail: miriam.diamond@utoronto.ca [Department of Earth Sciences, 22 Russell Street, University of Toronto, Toronto, ON M5S 3B1 (Canada); Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada)

2016-09-01

Cotton and polyester, physically and chemically different fabrics, were characterized for sorption of gas-phase polybrominated diphenyl ethers (PBDEs). Scanning electron microscopic (SEM) images and BET specific surface area (BET-SSA) analysis showed cotton's high microsurface area; NMR analysis showed richness of hexose- and aromatic-carbon in cotton and polyester, respectively. Cotton and polyester sorbed similar concentrations of gas-phase PBDEs in chamber studies, when normalized to planar surface area. However, polyester concentrations were 20–50 times greater than cotton when normalized to BET-SSA, greater than the 10 times difference in BET-SSA. The difference in sorption between cotton and polyester is hypothesized to be due to ‘dilution’ due to cotton's large BET-SSA and/or greater affinity of PBDEs for aromatic-rich polyester. Similar fabric-air area normalized distribution coefficients (K'{sub D}, 10{sup 3} to 10{sup 4} m) for cotton and polyester support air-side controlled uptake under non-equilibrium conditions. K'{sub D} values imply that 1 m{sup 2} of cotton or polyester fabrics would sorb gas-phase PBDEs present in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume at room temperature over one week, assuming similar air flow conditions. Sorption of PBDEs to fabrics has implications for their fate indoors and human exposure. - Highlights: • Sorption of gas-phase PBDEs by cotton and polyester fabrics • Similar sorption to cotton and polyester per unit planar surface area • Greater sorption by polyester/BET-SSA; cotton's dilution or polyester’s affinity • 1 m{sup 2} fabric sorbs PBDEs in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume • Clothing likely a large indoor sink of PBDEs and influence human exposure.

Copper-catalyzed difunctionalization of activated alkynes by radical oxidation-tandem cyclization/dearomatization to synthesize 3-trifluoromethyl spiro[4.5]trienones.

Science.gov (United States)

Hua, Hui-Liang; He, Yu-Tao; Qiu, Yi-Feng; Li, Ying-Xiu; Song, Bo; Gao, Pin; Song, Xian-Rong; Guo, Dong-Hui; Liu, Xue-Yuan; Liang, Yong-Min

2015-01-19

A copper-catalyzed difunctionalizing trifluoromethylation of activated alkynes with the cheap reagent sodium trifluoromethanesulfinate (NaSO2CF3 or Langlois' reagent) has been developed incorporating a tandem cyclization/dearomatization process. This strategy affords a straightforward route to synthesis of 3-(trifluoromethyl)-spiro[4.5]trienones, and presents an example of difunctionalization of alkynes for simultaneous formation of two carbon-carbon single bonds and one carbon-oxygen double bond. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polybrominated Diphenyl Ethers (PBDEs) in Surface Soils across Five Asian Countries: Levels, Spatial Distribution, and Source Contribution.

Science.gov (United States)

Li, Wen-Long; Ma, Wan-Li; Jia, Hong-Liang; Hong, Wen-Jun; Moon, Hyo-Bang; Nakata, Haruhiko; Minh, Nguyen Hung; Sinha, Ravindra Kumar; Chi, Kai Hsien; Kannan, Kurunthachalam; Sverko, Ed; Li, Yi-Fan

2016-12-06

A total of 23 polybrominated diphenyl ether (PBDE) congeners were measured in soil samples collected in areas with no known point source [urban/rural/background (U/R/B) sites] and in areas with known point source [brominated flame retardant (BFR)-related industrial sites (F sites) and e-waste recycling sites (E sites)] across five Asian countries. The highest PBDE concentrations were found in BFR-related industrial and e-waste recycling sites. The concentrations of PBDEs in U/R/B sites decreased in the following order: urban > rural > background sites. Total PBDE concentrations were dominated by BDE-209, while BDE-17, -85, -138, -191, -204, and -205 were the least abundant compounds. In both urban sites and rural sites, the mean concentrations of total PBDEs (∑ 23 BDEs) in soils decreased in the following order: Japan > China > South Korea > India > Vietnam. The concentrations of PBDEs in soils were comparable with those reported in other studies. Among the three commercial PBDE mixtures, relatively large contributions of commercial penta-BDE were observed in Vietnam, whereas deca-BDE was the dominant form in mixtures contributing from 55.8 ± 2.5 to 100.0 ± 1.2% of the total PBDEs in soils collected from other four countries. Regression analysis suggested that local population density (PD) is a good indicator of PBDEs in soils of each country. Significant and positive correlation between soil organic content and PBDE level was observed in Chinese soil for most nondeca-BDE homologues with their usage stopped 10 years ago, indicating its important role in controlling the revolatilization of PBDEs from soil and changing the spatial trend of PBDE in soil from the primary distribution pattern to the secondary distribution pattern, especially when primary emission is ceased.

New Calix[4]arene dibenzocrown ethers for selective sensing of cesium ion in aqueous environment

International Nuclear Information System (INIS)

Kim, Jong Seung; Kim, Jong Kuk; Choi, Wang Kyu; Lee, Kune Woo; Oh, Won Jin

1997-01-01

1,3-dialkoxycalix[4]arene dibenzocrown ethers (6-9) were successfully synthesized in the fixed 1,3-alternate conformation with over 90% yields by the reaction of corresponding 1,3dialkoxycalix[4]arenes 2-5 with dibenzodimesylate 13 in acetonitrile as a solvent in the presence of cesium carbonate as a base. In view of cyclization yield, the use of dimesylate is found to be better than that of dibenzoditosylate. With an unusual AB pattern in 1 H NMR spectrum for compound 9, it is suggested that conformational structure of 1,3-diallyloxycalix[4]arene dibenzocrown ether be less flexible than that of usual 1,3-alternate calixcrown ether, probably due to steric effects of two ally1 group. Complexation of the corresponding calix[4]arene 6-9 toward alkali metal ions using single flux method through bulk liquid membrane system was found to give a high cesium selectivity. 28 refs., 1 tab., 1 fig

New Calix[4]arene dibenzocrown ethers for selective sensing of cesium ion in aqueous environment

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Seung; Kim, Jong Kuk [Konyang University, Nonsan (Korea, Republic of); Choi, Wang Kyu; Lee, Kune Woo; Oh, Won Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

1,3-dialkoxycalix[4]arene dibenzocrown ethers (6-9) were successfully synthesized in the fixed 1,3-alternate conformation with over 90% yields by the reaction of corresponding 1,3dialkoxycalix[4]arenes 2-5 with dibenzodimesylate 13 in acetonitrile as a solvent in the presence of cesium carbonate as a base. In view of cyclization yield, the use of dimesylate is found to be better than that of dibenzoditosylate. With an unusual AB pattern in {sup 1}H NMR spectrum for compound 9, it is suggested that conformational structure of 1,3-diallyloxycalix[4]arene dibenzocrown ether be less flexible than that of usual 1,3-alternate calixcrown ether, probably due to steric effects of two ally1 group. Complexation of the corresponding calix[4]arene 6-9 toward alkali metal ions using single flux method through bulk liquid membrane system was found to give a high cesium selectivity. 28 refs., 1 tab., 1 fig.

In vitro antioxidant activity of pet ether extract of black pepper

Science.gov (United States)

Singh, Ramnik; Singh, Narinder; Saini, B.S.; Rao, Harwinder Singh

2008-01-01

Objective: To investigate the in vitro antioxidant activity of different fractions (R1, R2 and R3) obtained from pet ether extract of black pepper fruits (Piper nigrum Linn.) Materials and Methods: The fractions R1, R2 and R3 were eluted from pet ether and ethyl acetate in the ratio of 6:4, 5:5 and 4:6, respectively. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, superoxide anion radical, nitric oxide radical, and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. Results: The free radical scavenging activity of the different fractions of pet ether extract of P. nigrum (PEPN) increased in a concentration dependent manner. The R3 and R2 fraction of PEPN in 500 µg/ml inhibited the peroxidation of a linoleic acid emulsion by 60.48±3.33% and 58.89±2.51%, respectively. In DPPH free radical scavenging assay, the activity of R3 and R2 were found to be almost similar. The R3 (100µg/ml) fraction of PEPN inhibited 55.68±4.48% nitric oxide radicals generated from sodium nitroprusside, whereas curcumin in the same concentration inhibited 84.27±4.12%. Moreover, PEPN scavenged the superoxide radical generated by the Xanthine/Xanthine oxidase system. The fraction R2 and R3 in the doses of 1000µg/ml inhibited 61.04±5.11% and 63.56±4.17%, respectively. The hydroxyl radical was generated by Fenton's reaction. The amounts of total phenolic compounds were determined and 56.98 µg pyrocatechol phenol equivalents were detected in one mg of R3. Conclusions: P. nigrum could be considered as a potential source of natural antioxidant. PMID:20040947

Polybrominated diphenyl ethers in surface sediments of the Yangtze River Delta: Levels, distribution and potential hydrodynamic influence

International Nuclear Information System (INIS)

Chen Shejun; Gao Xiaojiang; Mai Bixian; Chen Zhuomin; Luo Xiaojun; Sheng Guoying; Fu Jiamo; Zeng, Eddy Y.

2006-01-01

A total of 32 surface sediments collected from the Yangtze River Estuary, Hangzhou Bay and the Qiantang River were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of ΣPBDEs (sum of 12 PBDE congeners without BDE 209) and BDE 209 varied from n.d. to 0.55 and from 0.16 to 94.6 ng/g, respectively. The spatial variability of ΣPBDEs concentrations indicated that waste discharge from the urban areas might been the main source of PBDEs in the Yangtze River Delta. BDE 209 was the predominant congener (∼90-100%) detected among the 13 congeners, consistent with the fact that technical deca-BDE mixtures are presently the dominant technical PBDE mixtures used in China. Compared to published data acquired from other locales, PBDE congeners with less than four bromines were more abundant in the present study area. The hydrodynamic conditions may likely be a significant factor in dictating the observed levels and congener distribution patterns of PBDEs. - This study discussed the possible effects of hydrodynamic conditions on the distribution of PBDEs in estuarine and marine boundary

Dissociative Photoionization of 1-Halogenated Silacyclohexanes: Silicon Traps the Halogen.

Science.gov (United States)

Bodi, Andras; Sigurdardottir, Katrin Lilja; Kvaran, Ágúst; Bjornsson, Ragnar; Arnason, Ingvar

2016-11-23

The threshold photoelectron spectra and threshold photoionization mass spectra of 1-halogenated-1-silacyclohexanes, for the halogens X = F, Cl, Br, and I, have been obtained using synchrotron vacuum ultraviolet radiation and photoelectron photoion coincidence spectroscopy. As confirmed by a similar ionization onset and density functional theory molecular orbitals, the ionization to the ground state is dominated by electron removal from the silacyclohexane ring for X = F, Cl, and Br, and from the halogen lone pair for X = I. The breakdown diagrams show that the dissociative photoionization mechanism is also different for X = I. Whereas the parent ions decay by ethylene loss for X = F to Br in the low-energy regime, the iodine atom is lost for X = I. The first step is followed by a sequential ethylene loss at higher internal energies in each of the compounds. It is argued that the tendency of silicon to lower bond angles stabilizes the complex cation in which C 2 H 4 is η 2 -coordinated to it, and which precedes ethylene loss. Together with the relatively strong silicon-halogen bonds and the increased inductive effect of the silacyclohexane ring in stabilizing the cation, this explains the main differences observed in the fragmentation of the halogenated silacyclohexane and halogenated cyclohexane ions. The breakdown diagrams have been modeled taking into account slow dissociations at threshold and the resulting kinetic shift. The 0 K appearance energies have been obtained to within 0.08 eV for the ethylene loss for X = F to Br (10.56, 10.51, and 10.51 eV, respectively), the iodine atom loss for X = I (10.11 eV), the sequential ethylene loss for X = F to I (12.29, 12.01, 11.94, and 11.86 eV, respectively), and the minor channels of H loss for X = F (10.56 eV) and propylene loss in X = Cl (also at 10.56 eV). The appearance energies for the major channels likely correspond to the dissociative photoionization reaction energy.

An enantioselective synthesis of S-[gamma]-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3-[sup 14]C] hydrochloride, an important metabolite of fluoxetine hydrochloride

Energy Technology Data Exchange (ETDEWEB)

Wheeler, W.J. (Lilly (Eli) and Co., Indianapolis, IN (United States). Lilly Research Labs.)

1992-06-01

The S-enantiomer of [gamma]-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3-[sup 14]C] hydrochloride has been prepared in eight steps from acetophenone-[carbonyl-[sup 14]C]. The key step in the synthesis involved the enantioselective reduction of R-2-chloroacetophenone-[1-[sup 14]C]with (-)-diisopinocampheyl-chloroborane in an 86.5% yield. The chlorohydrin was converted to R-phenyloxirane-[1-[sup 14]C], which was subsequently converted to the corresponding R-cyanohydrin by reaction with TMS-CN/CaO. Borane reduction and arylation, followed by salt formation yielded S-[gamma]-[(4-trifluoromethyl)phenoxy]benzenepropanamine-[3-[sup 14]C] hydrochloride. (author).

Occurrence of polybrominated diphenyl ethers in floor and elevated surface house dust from Shanghai, China.

Science.gov (United States)

Niu, Dong; Qiu, Yanling; Li, Li; Zhou, Yihui; Du, Xinyu; Zhu, Zhiliang; Chen, Ling; Lin, Zhifen

2018-04-24

House dust is the main source of human exposure to flame retardants by ingestion. This study investigated the occurrence of polybrominated diphenyl ethers (PBDEs) in indoor dust from 22 houses in Shanghai, China. House dust was separately collected from the floor and elevated furnishings surface (mostly between 0.5 and 2 m height) for comparison. The concentrations of ∑ 22 PBDEs ranged from 19.4 to 3280 ng/g (with a geometric mean of 203 ng/g) and from 55.1 to 792 ng/g (with a geometric mean of 166 ng/g) in floor dust (FD) and elevated surface dust (ESD), respectively. BDE-209 was the predominant congener, accounting for about 73.1% of total PBDE burdens. In terms of congener profiles, the comparison of FD and ESD revealed no significant differences except for the ratio of BDE-47/BDE-99. ESD samples displayed a ratio of BDE-47/BDE-99 very similar to commercial penta-BDE products DE-71 while the ratio in FD was exceptionally higher. Significant correlation was found between concentrations of commercial penta-BDE compositions in FD and ESD (p house dust exhibited temporal stability. Human exposure to PBDEs via dust ingestion was estimated. The highest daily intake of PBDEs was for toddlers by using 95th percentile concentrations of PBDEs via high dust ingestion in FD (23.07 ng/kg bw/day). About 20-fold difference in exposure estimates between toddlers and adults supports that toddlers are facing greater risk from indoor floor dust. Expectedly, this study highlighted the point that residents in Shanghai were exposed to low doses of PBDEs in house dust.

O interactions in 1,3-diphenyl-urea

Indian Academy of Sciences (India)

The synthesis, X-ray structure and role of intermolecular interactions have been studied in case of 1,3-diphenyl-urea, owing to its medicinal importance. The compound crystallizes in orthorhombic crystal system (space group, 21) with unit cell parameters, = 9.118(3), = 10.558(2), = 11.780(3) Å and = 4.

Pilot-scale incineration of wastes with high content of chlorinated and non-halogenated organophosphorus flame retardants used as alternatives for PBDEs

Energy Technology Data Exchange (ETDEWEB)

Matsukami, Hidenori, E-mail: matsukami.hidenori@nies.go.jp [Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506 (Japan); Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563 (Japan); Kose, Tomohiro [Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Watanabe, Mafumi [Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506 (Japan); Takigami, Hidetaka [Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506 (Japan); Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563 (Japan)

2014-09-15

Chlorinated and non-halogenated organophosphorus flame retardants (OPFRs) including tris(2-chloroisopropyl) phosphate (TCIPP), diethylene glycol bis(di(2-chloroisopropyl) phosphate) (DEG-BDCIPP), triphenyl phosphate (TPHP), and bisphenol A bis(diphenyl phosphate) (BPA-BDPP) have been used increasingly as alternatives to polybrominated diphenyl ethers and other brominated flame retardants. For this study, five batches of incineration experiments of wastes containing approximately 1% of TCIPP, DEG-BDCIPP, TPHP, and BPA-BDPP were conducted using a pilot-scale incinerator. Destruction and emission behaviors of OPFRs were investigated along with the effects on behaviors of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), and pentachlorophenol (PCP). Incineration conditions were chosen according to current regulations for waste incinerators in Japan and UNEP. The OPFRs in the input materials were mainly destroyed in the primary combustion with destruction efficiencies greater than 99.999%. Concentrations of the OPFRs in the exhaust gases and ash were, respectively, < 0.01–0.048 μg m{sup −3} and < 0.5–68 μg kg{sup −1}. Almost all of the total phosphorus in the input materials was partitioned into the ash, but less into final exit gases, indicating negligible emissions of volatile phosphorus compounds during incineration. Inputs of chlorinated OPFRs did not affect the formation markedly. Destruction and emission behaviors of unintentional POPs were investigated. Emissions of such POPs in exhaust gases and the ash were lower than the Japanese and international standards. Results show that even in wastes with high contents of chlorinated and non-halogenated OPFRs, waste incineration by the current regulations for the waste incinerators can control environmental emissions of

Pilot-scale incineration of wastes with high content of chlorinated and non-halogenated organophosphorus flame retardants used as alternatives for PBDEs

International Nuclear Information System (INIS)

Matsukami, Hidenori; Kose, Tomohiro; Watanabe, Mafumi; Takigami, Hidetaka

2014-01-01

Chlorinated and non-halogenated organophosphorus flame retardants (OPFRs) including tris(2-chloroisopropyl) phosphate (TCIPP), diethylene glycol bis(di(2-chloroisopropyl) phosphate) (DEG-BDCIPP), triphenyl phosphate (TPHP), and bisphenol A bis(diphenyl phosphate) (BPA-BDPP) have been used increasingly as alternatives to polybrominated diphenyl ethers and other brominated flame retardants. For this study, five batches of incineration experiments of wastes containing approximately 1% of TCIPP, DEG-BDCIPP, TPHP, and BPA-BDPP were conducted using a pilot-scale incinerator. Destruction and emission behaviors of OPFRs were investigated along with the effects on behaviors of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), and pentachlorophenol (PCP). Incineration conditions were chosen according to current regulations for waste incinerators in Japan and UNEP. The OPFRs in the input materials were mainly destroyed in the primary combustion with destruction efficiencies greater than 99.999%. Concentrations of the OPFRs in the exhaust gases and ash were, respectively, < 0.01–0.048 μg m −3 and < 0.5–68 μg kg −1 . Almost all of the total phosphorus in the input materials was partitioned into the ash, but less into final exit gases, indicating negligible emissions of volatile phosphorus compounds during incineration. Inputs of chlorinated OPFRs did not affect the formation markedly. Destruction and emission behaviors of unintentional POPs were investigated. Emissions of such POPs in exhaust gases and the ash were lower than the Japanese and international standards. Results show that even in wastes with high contents of chlorinated and non-halogenated OPFRs, waste incineration by the current regulations for the waste incinerators can control environmental emissions of OPFRs and

Halogenated flame retardants in the Great Lakes environment.

Science.gov (United States)

Venier, Marta; Salamova, Amina; Hites, Ronald A

2015-07-21

Flame retardants are widely used industrial chemicals that are added to polymers, such as polyurethane foam, to prevent them from rapidly burning if exposed to a small flame or a smoldering cigarette. Flame retardants, especially brominated flame retardants, are added to many polymeric products at percent levels and are present in most upholstered furniture and mattresses. Most of these chemicals are so-called "additive" flame retardants and are not chemically bound to the polymer; thus, they migrate from the polymeric materials into the environment and into people. As a result, some of these chemicals have become widespread pollutants, which is a concern given their possible adverse health effects. Perhaps because of their environmental ubiquity, the most heavily used group of brominated flame retardants, the polybrominated diphenyl ethers (PBDEs), was withdrawn from production and use during the 2004-2013 period. This led to an increasing demand for other flame retardants, including other brominated aromatics and organophosphate esters. Although little is known about the use or production volumes of these newer flame retardants, it is evident that some of these chemicals are also becoming pervasive in the environment and in humans. In this Account, we describe our research on the occurrence of halogenated and organophosphate flame retardants in the environment, with a specific focus on the Great Lakes region. This Account starts with a short introduction to the first generation of brominated flame retardants, the polybrominated biphenyls, and then presents our measurements of their replacement, the PBDEs. We summarize our data on PBDE levels in babies, bald eagles, and in air. Once these compounds came off the market, we began to measure several of the newer flame retardants in air collected on the shores of the Great Lakes once every 12 days. These new measurements focus on a tetrabrominated benzoate, a tetrabrominated phthalate, a hexabrominated diphenoxyethane

Enantioselective organocatalyzed Oxa-Michael-Aldol cascade reactions: Construction of chiral 4H-chromenes with a trifluoromethylated tetrasubstituted carbon stereocenter

KAUST Repository

Zhang, Jing; Ajitha, Manjaly John; He, Lin; Liu, Kai; Dai, Bin; Huang, Kuo-Wei

2015-01-01

The first organocatalytic asymmetric synthesis of 4H-chromenes bearing a trifluoromethylated tetrasubstituted carbon center is presented. Chiral secondary amines promote the oxa-Michael-aldol cascade reaction between alkynals and 2

Distribution and accumulation of polybrominated diphenyl ethers (PBDEs) in Hong Kong mangrove sediments.

Science.gov (United States)

Zhu, Haowen; Wang, Ying; Wang, Xiaowei; Luan, Tiangang; Tam, Nora F Y

2014-01-15

Polybrominated diphenyl ethers (PBDEs) have been used extensively as brominated flame retardants in various polymers, and have become serious environmental contaminants, particularly in coastal sediments. Mangrove wetlands are important coastal ecosystems in tropical and subtropical regions, and mangrove sediments are often the pollutant sinks due to their close proximity with human activities. In Hong Kong, sediment samples collected from five mangrove swamps were found to be contaminated with PBDEs and the eight measured BDE congeners, including BDE-28, -47, -99, -100, -153, -154, -183 and -209 were detected in all mangrove sediments, indicating that these pollutants were widespread in Hong Kong mangrove wetlands. Among the five swamps, relatively high concentrations of PBDEs were recorded in Mai Po mangrove swamp in the northwestern Hong Kong, which is part of the RAMSAR site but is severely influenced by the pollution from the Pearl River Delta. The depth profile of PBDEs in sediment cores collected from Mai Po also showed the inputs of PBDEs in this mangrove swamp increased year by year. In all sediments, the concentrations of BDE-209 were 1-2 orders of magnitude higher than the other congeners in the same sediment. The concentrations of BDE-209 and ∑PBDEs (defined as the sum of seven targeted BDE congeners except BDE-209) ranged from 1.53 to 75.9 ng g(-1) and from 0.57 to 14.4 ng g(-1), respectively. Among the targeted BDE congeners except BDE-209, slightly different composition was recorded among samples collected from different locations, with BDE-153 and -183 being the pre-dominated congeners. In all mangrove swamps, except Tai O in the southwest of Hong Kong, ∑PBDEs concentrations showed a common trend of landward>seaward>mudflat. The concentrations of ∑PBDEs were significantly correlated with total organic matter (TOM) content in sediments but not with the sediment particle sizes in each mangrove swamp. © 2013.

Direct or photostimulated luminescence after X-Ray irradiation of divalent europium in alkaline earth compounds containing some halides; Luminescence directe ou photostimulee apres irradiation X de l'europium divalent dans des familles de composes alcalino-terreux comportant un halogene

Energy Technology Data Exchange (ETDEWEB)

Merigou, C

1990-10-15

With a view for digitizing of radiological images, the luminescent properties of divalent europium in diverse halogen compounds involving strontium or barium have been studied. In halogen-rich compounds (MCl{sub 2}, M{sub 4}OCl{sub 6}, M{sub 5}SiO{sub 4}Cl{sub 6},... where M is Sr or Ba), the thermal extinction of the emission begins only above 300 K. High densities of coloured spots have been produced with X-ray irradiation. The combining of these 2 features has led to the obtention of high yields for argon laser stimulated luminescence in the case of Sr{sub 5}SiO{sub 4}Cl{sub 5}Br:Eu halogen silicate. Although these yields are high they stay below that of BaXF:Eu which is usually used in photon-stimulated screens.

Photolytic degradation of polybromodiphenyl ethers under UV-lamp and solar irradiations

Energy Technology Data Exchange (ETDEWEB)

Shih, Yang-hsin, E-mail: yhs@nchu.edu.tw [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Wang, Chun-Kang [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 402, Taiwan (China)

2009-06-15

Polybromodiphenyl ethers (PBDEs) are widely used flame retardant additives and have been mainly used in polymers for many plastic and electronic products. PBDEs have been found to bioaccumulate in both aquatic and terrestrial ecosystems and even human bodies. The technical product with the highest use is decabrominated diphenyl ether (BDE-209). Therefore, we chose to examine the solar and UV-lamp degradation of BDE-209. A linear increase of the photodegradation rate constant for BDE-209 was observed with the solar light intensity. The degradation reactions follow the pseudo-first-order kinetics. The photodegradation of BDE-209 produced other less brominated diphenyl ethers under ultraviolet light exposure, suggesting that the photodegradation of BDE-209 is a sequential dehalogenation mechanism. BDE-209 underwent rapid reductive debromination in these photodecomposition experiments. The formation rate constants of three nonabromodiphenyl ethers increase with the order of BDE-206, BDE-207 and BDE-208, indicating debromination mainly occurred at para > meta > ortho positions. These findings of the process properties and reductive debromination mechanism of the photolytic degradation of PBDEs can facilitate the design of remediation processes and also aid in predicting their fate in the environment.

Volatile organic compound measurements in the California/Mexico border region during SCOS97

International Nuclear Information System (INIS)

Zielinska, B.; Sagebiel, J.; Harshfield, G.; Pasek, R.

2001-01-01

Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone Study in the summer of 1997 (SCOS97). Integrated 3-h samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during intensive operational periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6-l canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C18 SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C 2 -C 12 ), CO, CO 2 , CH 4 , methyl t-butyl ether (MTBE), and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for 14 C 1 -C 7 carbonyl compounds. The concentrations of all species were higher at Mexicali than in Rosarito. A good correlation between total non-methane hydrocarbons (TNMHC), CO, and other pollutants associated with motor vehicle emissions observed for Mexicali indicates that the main source of TNMHC at this site is vehicular traffic

Transcriptomic Analysis of Gonadal Adipose Tissue in Male Mice Exposed Perinatally to 2,2′,4,4′-Tetrabromodiphenyl Ether (BDE-47

Directory of Open Access Journals (Sweden)

Aser Abrha

2018-03-01

Full Text Available For the majority of lipophilic compounds, adipose tissue is traditionally considered as a storage depot and only rarely as a target organ. Meanwhile, abnormalities in adipose tissue physiology induced by chemical exposure may contribute to the current epidemic of obesity and metabolic diseases. Polybrominated diphenyl ethers (PBDEs are a group of lipophilic flame retardants found in the majority of human samples in North America. Their ability to alter the physiology of adipose tissue is unknown. We exposed pregnant mice to 0.2 mg/kg body weight/day of BDE-47 perinatally. Transcriptomic changes in gonadal adipose tissue were analyzed in male offspring using the RNA-seq approach with subsequent bioinformatic analysis. The expression of genes of coagulation and complement cascade, de novo lipogenesis, and xenobiotic metabolism was altered in response to BDE-47 exposure. The affected molecular network included the following hubs: PPARα, HNF1A, and HNF4. These findings suggest that adipose tissue should be considered a target tissue for BDE-47, in addition to its role as a storage depot. This study also builds a background for a targeted search of sensitive phenotypic endpoints of BDE-47 exposure, including lipid profile parameters and coagulation factors in circulation. Additional studies are needed to investigate the role of PBDEs as an obesogen.

The Effect of Intermolecular Halogen Bond on 19F DNP Enhancement in 1, 4-Diiodotetrafluorobenzene/4-OH-TEMPO Supramolecular Assembly

Directory of Open Access Journals (Sweden)

GAO Shan

2017-12-01

Full Text Available Halogen bond, as hydrogen bond, is a non-covalent bond. Dynamic nuclear polarization (DNP technique has been used previously to study hydrogen bonds-mediated intermolecular interactions. However, no study has been carried out so far to study the halogen bond-mediated intermolecular interactions with DNP. In this work, 19F DNP polarization efficiency of the halogen bonds existing in supramolecular assembling by 4-OH-TEMPO and 1,4-diiodotetrafluorobenzene (DITFB was studied on a home-made DNP system. The formation of intermolecular halogen bonds appeared to increase 19F DNP polarization efficiency, suggesting that the spin-spin interactions among electrons were weakened by the halogen bonds, resulting in an increased T2e and a larger saturation factor.

Modern and historical fluxes of halogenated organic contaminants to a lake in the Canadian arctic, as determined from annually laminated sediment cores

International Nuclear Information System (INIS)

Stern, G.A.; Braekevelt, E.; Helm, P.A.; Bidleman, T.F.; Outridge, P.M.; Lockhart, W.L.; McNeeley, R.; Rosenberg, B.; Ikonomou, M.G.; Hamilton, P.; Tomy, G.T.; Wilkinson, P.

2005-01-01

Two annually laminated cores collected from Lake DV09 on Devon Island in May 1999 were dated using 210 Pb and 137 Cs, and analyzed for a variety of halogenated organic contaminants (HOCs), including polychlorinated biphenyls (PCBs), organochlorine pesticides, short-chain polychlorinated n-alkanes (sPCAs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated diphenyl ethers (PBDEs). Dry weight HOC concentrations in Lake DV09 sediments were generally similar to other remote Arctic lakes. Maximum HOC fluxes often agreed well with production maxima, although many compound groups exhibited maxima at or near the sediment surface, much later than peak production. The lower than expected HOC concentrations in older sediment slices may be due to anaerobic degradation and possibly to dilution resulting from a temporary increase in sedimentation rate observed between the mid-1960s and 1970s. Indeed, temporal trends were more readily apparent for those compound classes when anaerobic metabolites were also analyzed, such as for DDT and toxaphene. However, it is postulated here for the first time that the maximum or increasing HOC surface fluxes observed for many of the major compound classes in DV09 sediments may be influenced by climate variation and the resulting increase in algal primary productivity which could drive an increasing rate of HOC scavenging from the water column. Both the fraction (F TC ) and enantiomer fraction (EF) of trans-chlordane (TC) decreased significantly between 1957 and 1997, suggesting that recent inputs to the lake are from weathered chlordane sources. PCDD/Fs showed a change in sources from pentachlorophenol (PeCP) in the 1950s and 1960s to combustion sources into the 1990s. Improvements in combustion technology may be responsible for the reducing the proportion of TCDF relative to OCDD in the most recent slice

Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China

International Nuclear Information System (INIS)

Wang Chen; Li Wei; Chen Jiwei; Wang Hongqijie; Li Tongchao; Shen Guofeng; Shen Huizhong; Huang Ye; Wang Rong; Wang Bin; Zhang Yanyan; Tang Jianhui; Liu Wenxin; Wang Xilong; Tao Shu

2012-01-01

High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 ± 72 pg/m 3 ) and other 13 PBDEs (16 ± 12 pg/m 3 ) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively. - Graphical abstract: Concentration of PBDEs at each site of the studied area. Highlights: ► High levels of PBDEs with BDE-209 domination were detected in air in northern China. ► PBDE concentrations in rural residential areas were significantly higher than those in rural open fields. ► Proportions of BDE-209 in urban areas were higher than those in rural areas. ► PBDE concentrations were correlated to local population density and Gross Domestic Production. - In northern China, PBDEs in air in rural residential areas were significantly higher than those in open fields.

Spontaneous Generation of Chirality in Simple Diaryl Ethers.

Science.gov (United States)

Lennartson, Anders; Hedström, Anna; Håkansson, Mikael

2015-07-01

We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems. © 2015 Wiley Periodicals, Inc.

Polychlorinated biphenyls, organochlorinated pesticides, and polybrominated diphenyl ethers in the cerebral cortex of wild river otters (Lontra canadensis)

International Nuclear Information System (INIS)

Basu, Niladri; Scheuhammer, Anton M.; O'Brien, Mike

2007-01-01

We measured the levels of ortho-substituted polychlorinated biphenyls (PCB), organochlorinated pesticides (OCP), and polybrominated diphenyl ethers (PBDE) in the cerebral cortex of river otters (Lontra canadensis) trapped from Ontario and Nova Scotia between 2002 and 2004. The mean concentration of total PCBs was 70.9 ± 12.1 ng/g l.w., and congeners 153, 180 and 138 accounted for nearly 60% of the sum. The mean concentration of total OCPs was 21.2 ± 3.7 ng/g l.w., and hexachlorobenzene (32.6% of total) and DDE (28.1%) accounted for the majority. The mean concentration of total PBDEs was 3.2 ± 0.6 ng/g l.w., and congeners 99 (44.9%), 153 (30.5%), and 100 (24.7%) were measured at the indicated percentages. There was no relationship between these residue data and concentrations of brain mercury or neurochemical receptors and enzymes as determined in earlier studies on these same animals. - River otters accumulated PCBs, OCPs, and PBDEs, but at levels below thresholds for neurotoxic effects

Polybrominated diphenyl ethers do not affect metamorphosis but alter the proteome of the invasive slipper limpet Crepidula onyx.

Science.gov (United States)

Mukherjee, Joy; Po, Beverly H K; Chiu, Jill M Y; Wu, Rudolf S S; Qian, Pei-Yuan; Thiyagarajan, Vengatesen

2013-08-15

Man-made polybrominated diphenyl ethers (PBDEs) used as flame retardants in various consumer products may be harmful to marine organisms. Larvae of some marine invertebrates, especially invasive species, can develop resistance to PBDEs through altered protein expression patterns or proteome plasticity. This is the first report of a proteomics approach to study BDE-47 induced molecular changes in the invasive limpet Crepidula onyx. Larvae of C. onyx were cultured for 5 days (hatching to metamorphosis) in the presence of BDE-47 (1 μg L(-1)). Using a 2-DE proteomics approach with triple quadrupole and high-resolution TOF-MS, we showed that BDE-47 altered the proteome structure but not the growth or metamorphosis of C. onyx larvae. We found eight significant differentially expressed proteins in response to BDE-47, deemed the protein expression signature, consisting of cytoskeletal, stress tolerance, metabolism and energy production related proteins. Our data suggest C. onyx larvae have adequate proteome plasticity to tolerate BDE-47 toxicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Polychlorinated biphenyls, organochlorinated pesticides, and polybrominated diphenyl ethers in the cerebral cortex of wild river otters (Lontra canadensis)

Energy Technology Data Exchange (ETDEWEB)

Basu, Niladri [National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3 (Canada)]. E-mail: nbasu@uottawa.ca; Scheuhammer, Anton M. [National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3 (Canada); O' Brien, Mike [Furbearers and Upland Game, Nova Scotia Department of Natural Resources, Kentville, Nova Scotia, B4N 4E5 (Canada)

2007-09-15

We measured the levels of ortho-substituted polychlorinated biphenyls (PCB), organochlorinated pesticides (OCP), and polybrominated diphenyl ethers (PBDE) in the cerebral cortex of river otters (Lontra canadensis) trapped from Ontario and Nova Scotia between 2002 and 2004. The mean concentration of total PCBs was 70.9 {+-} 12.1 ng/g l.w., and congeners 153, 180 and 138 accounted for nearly 60% of the sum. The mean concentration of total OCPs was 21.2 {+-} 3.7 ng/g l.w., and hexachlorobenzene (32.6% of total) and DDE (28.1%) accounted for the majority. The mean concentration of total PBDEs was 3.2 {+-} 0.6 ng/g l.w., and congeners 99 (44.9%), 153 (30.5%), and 100 (24.7%) were measured at the indicated percentages. There was no relationship between these residue data and concentrations of brain mercury or neurochemical receptors and enzymes as determined in earlier studies on these same animals. - River otters accumulated PCBs, OCPs, and PBDEs, but at levels below thresholds for neurotoxic effects.

Oxidative transformation of polybrominated diphenyl ether congeners (PBDEs) and of hydroxylated PBDEs (OH-PBDEs).

Science.gov (United States)

Moreira Bastos, Patricia; Eriksson, Johan; Vidarson, Jenny; Bergman, Ake

2008-10-01

The historical and widespread use of polybrominated diphenyl ethers (PBDEs) as flame retardants in consumer products worldwide has caused PBDEs to now be regarded as pervasive environmental contaminants. Most recently, hydroxylated PBDEs (OH-PBDEs) and methoxylated PBDEs (MeO-PBDEs) have emerged as environmentally relevant due to reports of their natural production and metabolism. An important parameter for assessing the environmental impact of a chemical substance is persistence. By formulating the concept that persistence is the result of the substance's physicochemical properties and chemical reactivity, Green and Bergman have proposed a new methodology to determine the inherent persistence of a chemical. If persistence could be predicted by straightforward methods, substances with this quality could be screened out before large-scale production/manufacturing begins. To provide data to implement this concept, we have developed new methodologies to study chemical transformations through photolysis; hydrolysis, substitution, and elimination; and via oxidation. This study has focused on adapting an oxidative reaction method to be applicable to non-water soluble organic pollutants. PBDEs and one MeO-PBDE were dissolved in tetrahydrofuran/methanol and then diluted in alkaline water. The OH-PBDEs were dissolved in alkaline water prior to reaction. The oxidation degradation reaction was performed at 50 degrees C using potassium permanganate as described elsewhere. The pH was maintained at 7.6 with disodium hydrogen phosphate and barium hydrogen phosphate, the latter also serving as a trapping agent for manganate ions. The oxidation reactions were monitored by high-performance liquid chromatography and reaction rates were calculated. The OH-PBDEs have very fast oxidative transformation rates compared to the PBDEs. The reaction rates seem to be primarily dependent on substitution pattern of the pi-electron-donating bromine substituents and of bromine content. There are

Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

Energy Technology Data Exchange (ETDEWEB)

Yu Zhiqiang [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Liao Ru' e [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li Huiru, E-mail: huiruli@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Mo Ligui [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zeng Xiangying; Sheng Guoying; Fu Jiamo [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2011-10-15

In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of {Sigma}{sub 20}PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 {+-} 152 pg/m{sup 3} and 5.48 {+-} 1.28 pg/m{sup 3}, respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. - Highlights: > Atmospheric PBDEs of Shanghai were at moderate levels and dominated by BDE-209. > Particulate DP was low even Shanghai is not far from the DP manufacturing factory. > DP showed no obviously stereoselective process in air particles from Shanghai. > Significant positive correlation was found between particulate PBDEs and PBDD/Fs. - The moderate PBDEs levels with deca-BDE being the most important contributor and low DP levels in ambient air around Shanghai reflected their different usage in this area.

Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

International Nuclear Information System (INIS)

Yu Zhiqiang; Liao Ru'e; Li Huiru; Mo Ligui; Zeng Xiangying; Sheng Guoying; Fu Jiamo

2011-01-01

In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of Σ 20 PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 ± 152 pg/m 3 and 5.48 ± 1.28 pg/m 3 , respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. - Highlights: → Atmospheric PBDEs of Shanghai were at moderate levels and dominated by BDE-209. → Particulate DP was low even Shanghai is not far from the DP manufacturing factory. → DP showed no obviously stereoselective process in air particles from Shanghai. → Significant positive correlation was found between particulate PBDEs and PBDD/Fs. - The moderate PBDEs levels with deca-BDE being the most important contributor and low DP levels in ambient air around Shanghai reflected their different usage in this area.

Possibilities of analyzing dump and sewage gas, and determination of halogen and sulfur compounds

Energy Technology Data Exchange (ETDEWEB)

Eisenmann, R

1985-01-01

In connection with the utilization of refuse and sewage gas efficacions analytical methods are gaining increasing importance especially with regard to halogen and sulfur compounds. The paper describes various possibilities to determine those substances. Besides gas chromatography it takes into account classic analytical methods which can be superior in biogas analytics to modern physical processes. The advantages and disadvantages of each method are discussed and practical experiences obtained by their application reported.

The gas-chromatographic and gas-chromatographic-mass-spectrometric identification of halogen-containing organic compounds

Science.gov (United States)

Gidaspov, B. V.; Zenkevich, I. G.; Rodin, A. A.

1989-09-01

The problem of identifying halogen-containing organic compounds in their gas-chromatographic and gas-chromatographic-mass-spectrometric (GC-MS) determination in different materials has been examined. Particular attention has been paid not to the complete characterisation of methods for carrying out this analysis but to the most important problem of increasing the selectivity at the stages of sampling, separation, and interpretation of the gas-chromatographic and GC-MS information. The bibliography contains 292 references.

Polybrominated diphenyl ethers (PBDEs) in US meat and poultry: 2012-13 levels, trends and estimated consumer exposures.

Science.gov (United States)

Lupton, Sara J; Hakk, Heldur

2017-09-01

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants whose use has contaminated foods and caused subsequent human exposures. To address the issue of possible human exposure, samples from a 2012-13 US meat and poultry (beef, pork, chicken, turkey) study were analysed for seven PBDEs. The mean summed concentrations of the seven BDE congeners (ΣPBDE) from beef, pork, chicken and turkey were 0.40, 0.36, 0.19, and 0.76 ng g -1 lipid weight (lw). The range of ΣPBDEs for all meat classes was 0.01-15.78 ng g -1 lw. A comparison of this study with a 2007-08 study revealed a decline in the median ΣPBDEs for all four meat classes, a reduction of 25.9% to 70.0%, with pork, chicken and turkey PBDE residues being statistically lower relative to the 2007-08 study. BDEs 47 and 99 contributed the most to the ΣPBDE concentrations, indicating likely animal exposures to the penta-BDE formulation. Based on the reported data an estimate of US consumer daily intake of PBDEs from meat and poultry was 6.42 ng day -1 .

Concentrations of polybrominated diphenyl ethers, hexachlorobenzene and polycyclic aromatic hydrocarbons in various foodstuffs before and after cooking.

Science.gov (United States)

Perelló, Gemma; Martí-Cid, Roser; Castell, Victoria; Llobet, Juan M; Domingo, José L

2009-04-01

The cooking-induced changes in the levels of polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), and 16 polycyclic aromatic hydrocarbons (PAHs) in various foodstuffs were investigated. Foods included fish (sardine, hake and tuna), meat (veal steak, loin of pork, breast and thigh of chicken, and steak and rib of lamb), string bean, potato, rice, and olive oil. For each food item, raw and cooked (fried, grilled, roasted, boiled) samples were analyzed. There were some variations in the concentrations of PBDEs before and after cooking. However, they depended not only on the cooking process, but mainly on the specific food item. The highest HCB concentrations were found in sardine, being lower in cooked samples. All cooking processes enhanced HCB levels in hake, while very scarce differences could be noted in tuna (raw and cooked). In general terms, the highest PAH concentrations were found after frying by being the values especially notable in fish, excepting hake, where the highest total PAH levels corresponded to roasted samples. The results of this study show that, in general, cooking processes are only of a limited value as a means of reducing PBDE, HCB and PAH concentrations in food.

New evidences in the complexity of contamination of the lagoon of Venice: polybrominated diphenyl ethers (PBDEs) pollution.

Science.gov (United States)

Parolini, Marco; Binelli, Andrea; Marin, Maria Gabriella; Matozzo, Valerio; Masiero, Luciano; Provini, Alfredo

2012-04-01

This study presents the first evaluation of the current pollution by polybrominated diphenyl ethers (PBDEs) of surface sediments from the Lagoon of Venice. We focused the research on tri-to hepta-BDEs, the main components of penta- and octa-mixtures, which are considered to be the most toxic for the biocoenosis. The results pointed out a quite homogeneous contamination of this keystone European transitional environment, with ∑ (13)PBDEs values ranging from 0.39 to 6.78 ng/g dry weight; these values reflect low to moderate pollution levels, which is in conformity to other coastal European ecosystems. The average PBDE profile of the lagoon sediments follows this decreasing trend of congeners: BDE-47>BDE-99> >BDE-190>BDE-28>BDE-153>BDE-154>BDE-138, BDE-183, and BDE-17, which is similar to the worldwide distribution pattern. BDE-47 and BDE-99 revealed a recent use of a penta-BDE mixture, while the presence of hepta-BDEs (BDE-183 and BDE-190) in all of the sites can indicate the actual use of a deca-BDE formulation, because these congeners are considered to be debrominated byproducts of BDE-209 degradation.

Designing quantitative structure activity relationships to predict specific toxic endpoints for polybrominated diphenyl ethers in mammalian cells.

Science.gov (United States)

Rawat, S; Bruce, E D

2014-01-01

Polybrominated diphenyl ethers (PBDEs) are known as effective flame retardants and have vast industrial application in products like plastics, building materials and textiles. They are found to be structurally similar to thyroid hormones that are responsible for regulating metabolism in the body. Structural similarity with the hormones poses a threat to human health because, once in the system, PBDEs have the potential to affect thyroid hormone transport and metabolism. This study was aimed at designing quantitative structure-activity relationship (QSAR) models for predicting toxic endpoints, namely cell viability and apoptosis, elicited by PBDEs in mammalian cells. Cell viability was evaluated quantitatively using a general cytotoxicity bioassay using Janus Green dye and apoptosis was evaluated using a caspase assay. This study has thus modelled the overall cytotoxic influence of PBDEs at an early and a late endpoint by the Genetic Function Approximation method. This research was a twofold process including running in vitro bioassays to collect data on the toxic endpoints and modeling the evaluated endpoints using QSARs. Cell viability and apoptosis responses for Hep G2 cells exposed to PBDEs were successfully modelled with an r(2) of 0.97 and 0.94, respectively.

AQUATOX coupled foodweb model for ecosystem risk assessment of Polybrominated diphenyl ethers (PBDEs) in lake ecosystems

International Nuclear Information System (INIS)

Zhang, Lulu; Liu, Jingling

2014-01-01

The AQUATOX model considers the direct toxic effects of chemicals and their indirect effects through foodwebs. For this study, the AQUATOX model was applied to evaluating the ecological risk of Polybrominated diphenyl ethers (PBDEs) in a highly anthropogenically disturbed lake-Baiyangdian Lake. Calibration and validation results indicated that the model can adequately describe the dynamics of 18 biological populations. Sensitivity analysis results suggested that the model is highly sensitive to temperature limitation. PBDEs risk estimate results demonstrate that estimated risk for natural ecosystems cannot be fully explained by single species toxicity data alone. The AQUATOX model could provide a good basis in ascertaining ecological protection levels of “chemicals of concern” for aquatic ecosystems. Therefore, AQUATOX can potentially be used to provide necessary information corresponding to early warning and rapid forecasting of pollutant transport and fate in the management of chemicals that put aquatic ecosystems at risk. - Highlights: • AQUATOX model incorporates direct toxic effects and indirect ecological effects. • Ecological risk of PBDEs was assessed by the AQUATOX model. • The model could help determine ecological threshold of “chemicals of concern”. - Capsule abstract: Application of the AQUATOX model to assess the direct and indirect ecological risk of PBDEs

Halogenating reaction activity of aromatic organic compounds during disinfection of drinking water

International Nuclear Information System (INIS)

Guo Gaimei; Chen Xiaodong

2009-01-01

The halogenating reactions of five aromatic organic compounds (AOCs) with aqueous chlorine (HOCl/OCl - ) and aqueous bromine (HOBr/OBr - ) were studied with an aim to compare the formation properties of haloacetic acids (HAAs) for the corresponding chlorination or bromination reactions of AOCs, respectively. The experiment results indicated that the HAAs substitution efficiency for the bromination reactions of AOCs was greater than that for the chlorination reactions, and the formation of HAAs had a strong dependence on the chemical structure of AOCs. The chlorination or bromination reaction activities for the AOCs with electron donating functional groups were higher than that for them with electron withdrawing functional groups. The kinetic experiments indicated that the reactions of aqueous bromine with phenol were faster than those of aqueous chlorine with phenol and the halogen consumption exhibited rapid initial and slower consumption stages for the reactions of phenol with aqueous chlorine and bromine, respectively. In addition, the HAAs production for the chlorination reaction of phenol decreased with the increase of pH. These conclusions could provide the valuable information for the effective control of the disinfection by-products during drinking water treatment operation

Synthesis of Some Trifluoromethylated Cyclodextrin Derivatives and Analysis of Their Properties as Artificial Glycosidases and Oxidases

DEFF Research Database (Denmark)

Bjerre, Jeannette; Fenger, Thomas Hauch; Marinescu, Lavinia Georgeta

2007-01-01

Cyclodextrin derivatives containing trifluoromethyl groups at C6 of the A and D rings were synthesized for the purpose of creating artificial enzymes. The compounds were synthesized by perbenzylation of beta-cyclodextrin followed by selective A,D-debenzylation according to Sinaÿ. Subsequent...... deprotected. The trifluoromethylated alcohols were found to be weak artificial enzymes catalysing hydrolysis of nitrophenyl glycosides at neutral pH with a kcat/kuncat of up to 56. It is proposed that this catalysis is analogues to the catalysis performed by related cyanohydrins. The trifluoro ketones were...

Five-year trends of selected halogenated flame retardants in the atmosphere of Northeast China

Energy Technology Data Exchange (ETDEWEB)

Li, Wen-Long; Liu, Li-Yan; Song, Wei-Wei; Zhang, Zi-Feng; Qiao, Li-Na [International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Ma, Wan-Li, E-mail: mawanli002@163.com [International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Li, Yi-Fan, E-mail: ijrc_pts_paper@yahoo.com [International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); IJRC-PTS-NA, Toronto M2N 6X9 (Canada)

2016-01-01

This study collected 227 pairs of gas phase and particle phase air samples in a typical urban city of Northeast China from 2008 to 2013. Four alternative halogenated flame retardants for polybrominated diphenyl ethers (PBDEs) were analyzed, namely 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EHTBB), bis (2-ethylhexyl) tetrabromophthalate (BEHTBP), syn-dechlorane plus (syn-DP) and anti-dechlorane plus (anti-DP). The average concentrations for EHTBB and BEHTBP were 5.2 ± 20 and 30 ± 200 pg/m{sup 3}, respectively, while for syn-DP and anti-DP were 1.9 ± 5.1 and 5.8 ± 18 pg/m{sup 3}, respectively. Generally, they were frequently detected in the particle phase, and the gas/particle partitioning suggested they were the maximum partition chemicals. The fractional abundance of EHTBB (f{sub EHTBB}) and syn-DP (f{sub syn}) were comparable with those in other studies. Strong local sources were identified based on the air parcel backward trajectories and the potential source contribution function. The concentrations of these chemicals were significantly increased during this sampling campaign, possibly suggesting their increasing usages from 2008 to 2013 in China. - Highlights: • Five-year air samples were analyzed for four alternative HFRs. • BEHTBP and DP were frequently detected in the particle phase. • Local and nearby city sources of these HFRs were suggested. • Concentrations of these HFRs were significantly increased in the five-year period.

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

Energy Technology Data Exchange (ETDEWEB)

Ni Honggang; Cao Shanping; Chang Wenjing [Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Zeng Hui, E-mail: huizeng0608@gmail.com [Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

2011-07-15

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM{sub 2.5} (Particulate Matter up to 2.5 {mu}m in size) bounded {Sigma}{sub 15}PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM{sub 10} (Particulate Matter up to 10 {mu}m in size) bounded {Sigma}{sub 15}PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of {Sigma}{sub 15}PBDEs via dust inhalation and ingestion for adults reached {approx}141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: > Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. > PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. > The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. > Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

International Nuclear Information System (INIS)

Ni Honggang; Cao Shanping; Chang Wenjing; Zeng Hui

2011-01-01

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM 2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ 15 PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM 10 (Particulate Matter up to 10 μm in size) bounded Σ 15 PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ 15 PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: → Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. → PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. → The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. → Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

Acute and Developmental Behavioral Effects of Flame ...

Science.gov (United States)

As polybrominated diphenyl ethers are phased out, numerous compounds are emerging as potential replacement flame retardants for use in consumer and electronic products. Little is known, however, about the neurobehavioral toxicity of these replacements. This study evaluated the neurobehavioral effects of acute or developmental exposure to t-butylphenyl diphenyl phosphate (BPDP), 2-ethylhexyl diphenyl phosphate (EHDP), isodecyl diphenyl phosphate (IDDP), isopropylated phenyl phosphate (IPP), tricresyl phosphate (TMPP; also abbreviated TCP), triphenyl phosphate (TPHP; also abbreviated TPP), tetrabromobisphenol A (TBBPA), tris (2-chloroethyl) phosphate (TCEP), tris (1,3-dichloroisopropyl) phosphate (TDCIPP; also abbreviated TDCPP), tri-o-cresyl phosphate (TOCP), and 2,2-,4,4’-tetrabromodiphenyl ether (BDE-47) in zebrafish (Danio rerio) larvae. Larvae (n≈24 per dose per compound) were exposed to test compounds (0.4 - 120 µM) at sub-teratogenic concentrations either developmentally or acutely, and locomotor activity was assessed at 6 days post fertilization. When given developmentally, all chemicals except BPDP, IDDP and TBBPA produced behavioral effects. When given acutely, all chemicals produced behavioral effects, with TPHP, TBBPA, EHDP, IPP, and BPDP eliciting the most effects at the most concentrations. The results indicate that these replacement flame retardants may have developmental or pharmacological effects on the vertebrate nervous system. This study

Occurrence, characteristics and leakage of polybrominated diphenyl ethers in leachate from municipal solid waste landfills in China

International Nuclear Information System (INIS)

Li, Ying; Li, Jinhui; Deng, Chao

2014-01-01

Raw leachate samples were collected from various municipal solid waste (MSW) landfills in a densely populated city in North China to measure the levels and compositional patterns of polybrominated diphenyl ethers (PBDEs) in leachate. The total concentration of PBDEs ranged from 4.0 to 351.2 ng/L, with an average of 73.0 ng/L. BDE-209 dominated the congeners in most of the samples, followed by BDE-47 and -99. Higher PBDEs concentrations were found in leachate from younger landfill facilities in the urban area. Pearson correlation analysis implied a potential dependence of the PBDEs level on landfill age, suspended solids and dissolved organic carbon, while the results of principal component analysis (PCA) suggested potential origins and transportation of PBDEs in leachate. The Monte Carlo method was adopted to estimate the annual leakage of PBDEs into the underground environment nationwide, based on two main scenarios: simple landfills with inadequate liner systems and composite-lined landfills with defective geomembranes. -- Highlights: • Levels and congener patterns of PBDEs in landfill leachate from China are measured. • Pollution loading of PBDEs in leachate is identified through comparative analysis. • Leachate properties perform moderate impact on the occurrence of PBDEs. • Both commercial and decomposition origins contribute to lower brominated congeners. • Leakage rate of PBDEs due to inadequate liner is estimated nationwide. -- This paper determined the levels and distribution of PBDEs in MSW landfill leachate and predicted the leakage of PBDEs from sanitary landfills into the underground environment across China

Copper-Catalyzed Decarboxylative Trifluoromethylation of Propargyl Bromodifluoroacetates.

Science.gov (United States)

Ambler, Brett R; Peddi, Santosh; Altman, Ryan A

2014-07-15

The development of efficient methods for accessing fluorinated functional groups is desirable. Herein, we report a two-step method that utilizes catalytic Cu for the decarboxylative trifluoromethylation of propargyl bromodifluoroacetates. This protocol affords a mixture of propargyl trifluoromethanes and trifluoromethyl allenes.

Regulated and Unregulated Halogenated Flame Retardants in Peregrine Falcon Eggs from Greenland

DEFF Research Database (Denmark)

Vorkamp, Katrin; Falk, Knud; Møller, Søren

2018-01-01

Median levels of regulated flame retardants, i.e. polybrominated diphenyl ethers (PBDEs), brominated biphenyl (BB) 153 and hexabromocyclododecane (HBCD) in 33-48 eggs of peregrine falcons (Falco peregrinus) from Greenland were 1900, 359 and 5.98 ng/g lipid weight (lw) and generally intermediate...

40 CFR 721.1000 - Benzenamine, 3-chloro-2,6-dinitro-N,N-dipropyl-4-(tri-fluoro-methyl)-.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine, 3-chloro-2,6-dinitro-N,N-dipropyl-4-(tri-fluoro-methyl)-. 721.1000 Section 721.1000 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1000 Benzenamine, 3-chloro-2,6-dinitro-N,N...

The environmental fate of polybrominated diphenyl ethers in the Great Lakes Basin

Science.gov (United States)

Gouin, Todd William

Semi-volatile organic compounds, such as the polybrominated diphenyl ethers (PBDEs) have the potential to undergo long-range atmospheric transport (LRAT) to remote locations, which can increase the exposure of sensitive ecosystems to potentially harmful substances. Regulatory instruments, such as the Stockholm Convention on persistent organic pollutants (POPs), have been implemented to limit and/or prevent this exposure. Through the acquisition of scientific data, knowledge can be gained about the environmental fate and human exposure of chemical substances, and the risks associated with using those substances assessed. PBDEs are a class of flame retardants that are used in a wide range of commercial products. In response to growing concern over the detection of PBDEs in remote regions, a number of regulatory bodies have implemented measures to restrict the use of PBDEs. Using a suite of environmental fate models it is shown that PBDEs will most likely partition to organic carbon in soil and sediment, and that their persistence in the environment will be strongly influenced by their reactivity in those compartments. The transport potential of the PBDEs is investigated using the transport and persistence level III model TaPL3, using model environments with and without vegetation. It is suggested that the LRAT potential of the PBDEs is likely to be greater for the more volatile lower brominated congeners than for the higher brominated congeners, and that the LRAT may be sensitive to seasonal changes in the environment, such as temperature, vegetation and changes in precipitation. Furthermore, model results suggest that the PBDEs may be subject to a "spring pulse" effect, whereby concentrations are elevated in air during the early spring. Field studies support the theory of a "spring pulse" effect, where concentrations were observed to be five times greater during the period between snowmelt and bud burst than the average concentration before and after, but conclude

多溴联苯醚健康效应的研究进展%Health Effects of Polybrominated Diphenyl Ethers:a review of recent studies

Institute of Scientific and Technical Information of China (English)

张慧慧; 于国伟; 牛静萍

2011-01-01

多溴联苯醚是一种在消费品中广泛应用的溴系阻燃剂,由于其具有亲脂性、持久性、远距离迁移性和生物富集等特点,容易在环境和人体中聚积,对人产生健康危害,主要有肝脏毒性、内分泌干扰作用、生殖毒性、免疫毒性和神经毒性等.该文主要从实验研究和人群流行病学调查两方面对近年来国内外关于PBDEs健康效应研究进行综述.%Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardant in various consumer products. They are easy to accumulate in the environment and human body due to their lipotropy, long half -life, long -range environmental transport and biomagnification. These compounds were found to induce toxicity to liver, endocrine system, reproduction, immune and nervous system. Based on the experimental studies and epidemiology surveys on PBDEs at home and abroad,this literature review summarized the research status of PBDEs' health effects in recent years.

Transcriptional and epigenetic mechanisms underlying enhanced in vitro adipocyte differentiation by the brominated flame retardant BDE-47

DEFF Research Database (Denmark)

Kamstra, Jorke H; Hruba, Eva; Blumberg, Bruce

2014-01-01

Recent studies suggest that exposure to endocrine-disrupting compounds (EDCs) may play a role in the development of obesity. EDCs such as the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) have been shown to enhance adipocyte differentiation in the murine 3T3-L1 model. The mech......Recent studies suggest that exposure to endocrine-disrupting compounds (EDCs) may play a role in the development of obesity. EDCs such as the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) have been shown to enhance adipocyte differentiation in the murine 3T3-L1 model....... The mechanisms by which EDCs direct preadipocytes to form adipocytes are poorly understood. Here, we examined transcriptional and epigenetic mechanisms underlying the induction of in vitro adipocyte differentiation by BDE-47. Quantitative high content microscopy revealed concentration-dependent enhanced...

Synthesis and Herbicidal Activity of 5-Heterocycloxy-3-substituted-1-(3-trifluoromethyl)phenyl-1H-pyrazole

Institute of Scientific and Technical Information of China (English)

XU Han; HU Xu-hong; ZOU Xiao-mao; ZHU You-quan; LIU Bin; HU Fang-zhong; YANG Hua-zheng

2012-01-01

The authors synthesized a series of novel 5-heterocycloxy-3-substituted-1-(3-trifluoromethyl)phenyl-1H- pyrazole derivatives.Herbicidal activities of the two intermediate compounds and thirteen target compounds were evaluated via Brassica napus and Echinochloa crusgalli(L.) Beauv tests.Bioassay results show that some of the compounds exhibit better inhibiting activities against Brassica napus and some of the compounds exhibit bleaching activities against Echinochloa crusgalli(L.) Beauv at 100 μg/mL.

Species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the Chesapeake Bay region, USA

Energy Technology Data Exchange (ETDEWEB)

Chen Da, E-mail: chen@vims.ed [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Hale, Robert C. [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Watts, Bryan D. [Center for Conservation Biology, College of William and Mary, Williamsburg, VA 23185 (United States); La Guardia, Mark J.; Harvey, Ellen [Department of Environmental and Aquatic Animal Health, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062 (United States); Mojica, Elizabeth K. [Center for Conservation Biology, College of William and Mary, Williamsburg, VA 23185 (United States)

2010-05-15

Compared to organochlorines, little is known about polybrominated diphenyl ether (PBDE) contamination of birds of prey breeding in the Chesapeake Bay, the largest estuary in the U.S. This study examined and compared PBDE contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. Several legacy persistent organic pollutants such as PCBs and DDE were also investigated. The level of urbanization of the landscape appeared to influence the level of PBDE exposure. PBDE congener distribution patterns varied between piscivorous and terrestrial-feeding birds. This suggests individual congeners may be subject to differences in bioaccumulation, biomagnification or metabolism in the aquatic and terrestrial food webs. Biomagnification of PBDEs was studied in the Bay aquatic food chains for the first time. A biomagnification factor of 25.1 was estimated for SIGMAPBDEs for the fish - osprey egg food chain. Hazard quotients, applied as a preliminary evaluation, indicated that PBDEs may pose a moderate hazard to ospreys and peregrine falcons through impairment of reproductive performance. - Birds of prey breeding in the Chesapeake Bay (USA) exhibited species-specific PBDE accumulation patterns.

Species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the Chesapeake Bay region, USA

International Nuclear Information System (INIS)

Chen Da; Hale, Robert C.; Watts, Bryan D.; La Guardia, Mark J.; Harvey, Ellen; Mojica, Elizabeth K.

2010-01-01

Compared to organochlorines, little is known about polybrominated diphenyl ether (PBDE) contamination of birds of prey breeding in the Chesapeake Bay, the largest estuary in the U.S. This study examined and compared PBDE contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. Several legacy persistent organic pollutants such as PCBs and DDE were also investigated. The level of urbanization of the landscape appeared to influence the level of PBDE exposure. PBDE congener distribution patterns varied between piscivorous and terrestrial-feeding birds. This suggests individual congeners may be subject to differences in bioaccumulation, biomagnification or metabolism in the aquatic and terrestrial food webs. Biomagnification of PBDEs was studied in the Bay aquatic food chains for the first time. A biomagnification factor of 25.1 was estimated for ΣPBDEs for the fish - osprey egg food chain. Hazard quotients, applied as a preliminary evaluation, indicated that PBDEs may pose a moderate hazard to ospreys and peregrine falcons through impairment of reproductive performance. - Birds of prey breeding in the Chesapeake Bay (USA) exhibited species-specific PBDE accumulation patterns.

Levels and distribution of polybrominated diphenyl ethers (PBDEs) in the freshwater environment surrounding a PBDE manufacturing plant in China

International Nuclear Information System (INIS)

Xu Jie; Gao Zishen; Xian Qiming; Yu Hongxia; Feng Jianfang

2009-01-01

Polybrominated diphenyl ethers (PBDEs) were determined in muscle, liver and eggs of freshwater fishes and surface sediments from the Nongkang River in Jinhu, Jiangsu Province, China. The present study is the first to report PBDE concentrations in the freshwater environment surrounding a PBDE manufacturing plant in China. The concentrations of 13 PBDE congeners in muscle, liver and eggs of freshwater fishes ranged from < LOD to 130, < LOD to 252 and < LOD to 33.3 ng/g lipid wt, respectively, while the concentrations of 13 PBDE congeners in surface sediments from sewage outfall, upstream and downstream of the river were 52, 9.2, 7.1 ng/g organic carbon wt, respectively. Contamination by PBDEs in this area was not serious when compared with other regions of the world. A relatively high proportion of BDE-183 was found, consistent with the octa-BDE technical mixtures from the manufacturing plant by the side of the river. - The first study to report concentrations of PBDEs in the freshwater environment surrounding a PBDE manufacturing plant in China.

SYNTHESIS OF 4’-ALLYLBENZO-3N-CROWN-N ETHERS AND THEIR MASS SPECTRA COMPARED WITH BENZO-3N-CROWN-N ETHERS

OpenAIRE

Anwar, Chairil

2008-01-01

Synthesis of 4’allylbenzo-3n-crown-n ethers was carried out by reacting demethylated eugenol with α,ω-dichloro-oligoethylene glycols in 1-butanol under basic condition. The mass spectra of 4’allylbenzo-3n-crown-n and benzo-3n-crown-n were investigated by mass spectrometry using electron impact under 70 eV of electron bombardment as ionisation method. The difference between the group of compounds is only the present of allyl moiety as a side chain at the other side of benzene ring. The first g...

Biogeochemistry of Halogenated Hydrocarbons

Science.gov (United States)

Adriaens, P.; Gruden, C.; McCormick, M. L.

2003-12-01

Halogenated hydrocarbons originate from both natural and industrial sources. Whereas direct anthropogenic emissions to the atmosphere and biosphere are often easy to assess, particularly when they are tied to major industrial activities, the attribution of emissions to other human activities (e.g., biomass burning), diffuse sources (e.g., atmospheric discharge, run off), and natural production (e.g., soils, fungi, algae, microorganisms) are difficult to quantify. The widespread occurrence of both alkyl and aryl halides in groundwater, surface water, soils, and various trophic food chains, even those not affected by known point sources, suggests a substantial biogeochemical cycling of these compounds (Wania and Mackay, 1996; Adriaens et al., 1999; Gruden et al., 2003). The transport and reactive fate mechanisms controlling their reactivity are compounded by the differences in sources of alkyl-, aryl-, and complex organic halides, and the largely unknown impact of biogenic processes, such as enzymatically mediated halogenation of organic matter, fungal production of halogenated hydrocarbons, and microbial or abiotic transformation reactions (e.g., Asplund and Grimvall, 1991; Gribble, 1996; Watling and Harper, 1998; Oberg, 2002). The largest source may be the natural halogenation processes in the terrestrial environment, as the quantities detected often exceed the amount that can be explained by human activities in the surrounding areas ( Oberg, 1998). Since biogeochemical processes result in the distribution of a wide range of halogenated hydrocarbon profiles, altered chemical structures, and isomer distributions in natural systems, source apportionment (or environmental forensics) can often only be resolved using multivariate statistical methods (e.g., Goovaerts, 1998; Barabas et al., 2003; Murphy and Morrison, 2002).This chapter will describe the widespread occurrence of halogenated hydrocarbons, interpret their distribution and biogeochemical cycling in light of

Bioaccumulation of polybrominated diphenyl ethers and decabromodiphenyl ethane in fish from a river system in a highly industrialized area, South China

International Nuclear Information System (INIS)

He, Ming-Jing; Luo, Xiao-Jun; Chen, Man-Ying; Sun, Yu-Xin; Chen, She-Jun; Mai, Bi-Xian

2012-01-01

Polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE) were determined in water, sediment, and three fish species from the Dongjiang River, a highly polluted river by brominated flame retardants in South China due to the intensive industry activities. The stable isotope analysis was used to compare differences between the feeding ecology of the fish species. The bioaccumulations of PBDEs and DBDPE were evaluated by calculation of bioaccumulation factors (BAFs) and biota-sediment accumulation factors (BSAFs). Two potential debromination products of DBDPE were detected in sediment. The occurrence of these two compounds probably ascribed to the thermal degradation during instrumental analysis but degradation in the environment cannot be ruled out. Three fish species showed two quite different PBDE congener profiles. Two carp species were dominated by BDE47 while plecostomus were dominated by both BDE47 and BDE99. The contributions of higher brominated congeners were higher in plecostomus than in two carp species. This different PBDE congener profile can be attributed to the difference in metabolism and feeding habits among fish species. The calculated BAFs for PBDE congeners follow a bioaccumulation model. The BSAFs for all PBDE congeners except for BDE47 and BDE100 were less than unit, implying that bioavailability of PBDEs in sediments is low. Contrary to expectation, the BAFs value of DBDPE was one order of magnitude higher than that of BDE209 in fish, which can partly attributed to the absence of debromination of DBDPE in fish. The calculated BAFs for DBDPE indicated that this compound can significantly accumulate in fish. - Highlights: ►Deca-BDE had gradually substituted by DBDPE in study area. ►Two debrominated products of DBDPE were the result of thermal degradation in instrumental analysis. ►Metabolism and diet were causes for the different PBDE congener profile among fish species. ►Significant bioaccumulation of DBDPE was

Measurement and modeling of diel variability of polybrominated diphenyl ethers and chlordanes in air.

Science.gov (United States)

Moeckel, Claudia; Macleod, Matthew; Hungerbühler, Konrad; Jones, Kevin C

2008-05-01

Short-term variability of concentrations of polybrominated diphenyl ethers (PBDEs) and chlordanes in air at a semirural site in England over a 5 day period is reported. Four-hour air samples were collected during a period dominated by a high pressure system that produced stable diel (24-h) patterns of meteorological conditions such as temperature and atmospheric boundary layer height. PBDE and chlordane concentrations showed clear diel variability with concentrations in the afternoon and evening being 1.9 - 2.7 times higher than in the early morning. The measurements are interpreted using a multimedia mass balance model parametrized with forcing functions representing local temperature, atmospheric boundary layer height, wind speed and hydroxyl radical concentrations. Model results indicate that reversible, temperature-controlled air-surface exchange is the primary driver of the diel concentration pattern observed for chlordanes and PBDE 28. For higher brominated PBDE congeners (47, 99 and 100), the effect of variable atmospheric mixing height in combination with irreversible deposition on aerosol particles is dominant and explains the diel patterns almost entirely. Higher concentrations of chlordanes and PBDEs in air observed at the end of the study period could be related to likely source areas using back trajectory analysis. This is the first study to clearly document diel variability in concentrations of PBDEs in air over a period of several days. Our model analysis indicates that high daytime and low nighttime concentrations of semivolatile organic chemicals can arise from different underlying driving processes, and are not necessarily evidence of reversible air-surface exchange on a 24-h time scale.

Plant consumption by grizzly bears reduces biomagnification of salmon-derived polychlorinated biphenyls, polybrominated diphenyl ethers, and organochlorine pesticides.

Science.gov (United States)

Christensen, Jennie R; Yunker, Mark B; MacDuffee, Misty; Ross, Peter S

2013-04-01

The present study characterizes the uptake and loss of persistent organic pollutants (POPs) in grizzly bears (Ursus arctos horribilis) by sampling and analyzing their terrestrial and marine foods and fecal material from a remote coastal watershed in British Columbia, Canada. The authors estimate that grizzly bears consume 341 to 1,120 µg of polychlorinated biphenyls (PCBs) and 3.9 to 33 µg of polybrominated diphenyl ethers daily in the fall when they have access to an abundant supply of returning salmon. The authors also estimate that POP elimination by grizzly bears through defecation is very low following salmon consumption (typically 100% for PCBs and organochlorine pesticides). Excretion of individual POPs is largely driven by a combination of fugacity (differences between bear and food concentrations) and the digestibility of the food. The results of the present study are substantiated by a principal components analysis, which also demonstrates a strong role for log KOW in governing the excretion of different POPs in grizzly bears. Collectively, the present study's results reveal that grizzly bears experience a vegetation-associated drawdown of POPs previously acquired through the consumption of salmon, to such an extent that net biomagnification is reduced. Copyright © 2013 SETAC.

IRIS Toxicological Review of 2,2',4,4'-Tetrabromodiphenyl ...

Science.gov (United States)

The U.S. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessments of congeners of polybrominated diphenyl ethers (PDBEs), this review is about 2,2',4,4'-Tetrabromodiphenyl Ether, or commonly referred to as tetraBDE (BDE-47). Following the external peer review this assessment will appear in the Integrated Risk Information System (IRIS) database. Peer review will ensure that science is used credibly and appropriately in derivation of the dose-response assessments and toxicological characterization. EPA is updating the Integrated Risk Information System (IRIS) health assessments for the PBDEs.

Labelling of some iodinated organic compounds by halogen exchange in organic media

International Nuclear Information System (INIS)

Hallaba, E.; Suhybani, A.Al-; Khowaiter, S.Al-; Abdel-Wahid, M.

1983-01-01

Describes a general method for labelling Rose Bengal in an organic medium. An isotopic exchange technique with interactive iodine as carrier for radioiodine is used. The effect of temperature, carrier, pH of the solvent and solvent are investigated. The optimum conditions for maximum yield of exchange are: .0.2 micro mole carrier inactive iodine per one micro mole of Rose Bengal, reaction mixture is 10ml ethyl alcohol 96% as a solvent for Rose Bengal and 3ml of ether or carbon tetrachloride containing the inactive and radioiodine. In case of ether, the reaction is slow and is completed in two hours with maximum yield of 90% at boiling temperature. Addition of 175 λ of 1 M acetate buffer with carbon tetrachloride gave a yield of 90% in one hour. This method can be applied successfully to label any iodinated organic compound, such as hypuran, thyroxine, tyrosine or aliphatic fatty acids, for application in nuclear medicine. 10 Ref

m-Trifluoromethyl-diphenyl Diselenide Regulates Prefrontal Cortical MOR and KOR Protein Levels and Abolishes the Phenotype Induced by Repeated Forced Swim Stress in Mice.

Science.gov (United States)

Rosa, Suzan Gonçalves; Pesarico, Ana Paula; Martini, Franciele; Nogueira, Cristina Wayne

2018-04-05

The present study aimed to investigate the m-trifluoromethyl-diphenyl diselenide [(m-CF 3 -PhSe) 2 ] effects on prefrontal cortical MOR and KOR protein levels and phenotype induced by repeated forced swim stress (FSS) in mice. Adult Swiss mice were subjected to repeated FSS sessions, and after that, they performed the spontaneous locomotor/exploratory activity, tail suspension, and splash tests. (m-CF 3 -PhSe) 2 (0.1 to 5 mg/kg) was administered to mice 30 min before the first FSS session and 30 min before the subsequent repeated FSS. (m-CF 3 -PhSe) 2 abolished the phenotype induced by repeated FSS in mice. In addition, a single FSS session increased μ but reduced δ-opioid receptor contents, without changing the κ content. Mice subjected to repeated FSS had an increase in the μ content when compared to those of naïve group or subjected to single FSS. Repeated FSS induced an increase of δ-opioid receptor content compared to those mice subjected to single FSS. However, the δ-opioid receptor contents were lower than those found in the naïve group. The mice subjected to repeated FSS showed an increase in the κ-opioid receptor content when compared to that of the naïve mice. (m-CF 3 -PhSe) 2 regulated the protein contents of μ and κ receptors in mice subjected to repeated FSS. These findings demonstrate that (m-CF 3 -PhSe) 2 was effective to abolish the phenotype induced by FSS, which was accompanied by changes in the contents of cortical μ- and κ-opioid receptors.

ESR studies of Bunsen-type methane-air flames. II. The effects of the addition of halogenated compounds to the secondary air on the hydrogen atoms in the flame

Energy Technology Data Exchange (ETDEWEB)

Noda, S; Fujimoto, S; Claesson, O; Yoshida, H

1983-09-01

Hydrogen atoms in a methane-air Bunsen-type flame were detected by the flame-in-cavity ESR method. The addition of a halogenated compound to the secondary air reduced the H-atom concentration linearly with an increase in additive concentration. These 8 halogenated compounds examined showed increased effectiveness in scavenging H atoms in this order: hydrochloric acid < dichlorodifluoromethane < chloroform < methyl chloride < methylene chloride < trichlorofluoromethane < carbon tetrachlorie < methyl bromide. The chemical effects of these additives on the combustion reactions agree well with the inhibitor indices for these compounds. 14 references, 3 figures.

Development of a liquid chromatography-electrospray chemical ionization tandem mass spectrometry analytical method for analysis of eleven hydroxylated polybrominated diphenyl ethers.

Science.gov (United States)

Feo, Maria Luisa; Barón, Enrique; Aga, Diana S; Eljarrat, Ethel; Barceló, Damià

2013-08-02

Recently, hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have emerged as environmentally relevant pollutants due to recent reports of their natural production and metabolism. Recent mechanistic studies in human and rats have shown that some OH-PBDEs are more potent than parent compounds (PBDEs) and may contribute substantially to neurodevelopmental disorders by direct neurotoxicity, or indirectly through altered thyroid disruption. However, analytical methodologies for determination of OH-PBDEs are currently limited. In this study a robust liquid chromatography-electrospray tandem triple quadrupole-linear ion trap mass spectrometer (LC-ESI-QqLIT-MS-MS) in negative mode method was developed for the determination of eleven OH-tri- to OH-hexa-PBDEs. Two different columns were tested and compared for chromatographic separation: a C18 BetaBasic and a Purospher STAR RP 18, working at pH 8 and 10, respectively. Mobile phase (acetonitrile:water) was optimized by changing the pH of the aqueous phase and the concentration of the organic modifier (methanol). The MS-MS parameters (declustering potential (DP), collision energy (CE) and cell exit potential (CXP)) were optimized. Selected reaction monitoring (SRM) was used in order to increase sensitivity. Two SRM transitions ([M-H](-)>[Br](-)) were selected for each OH-PBDE, one for quantification and the second one for confirmation. Under the optimized conditions, the instrumental limits of detection were between 0.17 and 0.72injectedpg. The method provided good linearity (r>0.99 for a concentration range of 0.30-100ng/mL), accuracy and precision (%Dev and %RSD≤20% for intra- and inter-assays). Copyright © 2013 Elsevier B.V. All rights reserved.

Age and seasonal variability of polybrominated diphenyl ethers in free-ranging East Greenland polar bears (Ursus maritimus)

International Nuclear Information System (INIS)