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We have studied the fragmentation of the brominated cyclic hydrocarbons bromocyclo-propane, bromocyclo-butane, and bromocyclo-pentane upon Br(3d) and C(1s) inner-shell ionization using coincidence ion momentum imaging. We observe a substantial yield of CH3+ fragments, whose formation requires intramolecular hydrogen (or proton) migration, that increases with molecular size, which contrasts with prior observations of hydrogen migration in linear hydrocarbon molecules. Furthermore, by inspecting the fragment ion momentum correlations of three-body fragmentation channels, we conclude that CHx+ fragments (with x = 0, ..., 3) with an increasing number of hydrogens are more likely to be produced via sequential fragmentation pathways. Overall trends in the molecular-size-dependence of the experimentally observed kinetic energy releases and fragment kinetic energies are explained with the help of classical Coulomb explosion simulations. [ABSTRACT FROM AUTHOR]

Benzalkonium salts are widely used in the composition of antimicrobial preparations in industry and everyday life and as algaecides to treat pool water. The disinfection of tap or waste water with active chlorine in the presence of natural or anthropogenic bromide anions or using bromine as a pool water disinfectant creates conditions for the interaction of benzalkonium cations with active bromine to form disinfection by-products. This study presents the results of a model benzalkonium bromination with the identification of the resulting products by high-performance liquid and gas chromatography combined with high-resolution mass spectrometry. The primary transformation products are monobromo derivatives formed by the radical substitution of hydrogen atoms of the alkyl chain with bromine. Their further transformations yield dibromo-, hydroxy-, and hydroxybromo derivatives. The final products of the deep degradation of benzalkonium are bromoform, bromoacetonitrile, and several brominated hydrocarbons. [ABSTRACT FROM AUTHOR]

Five long-chain hydrocarbons and a new brominated nitrogenous terpenoid were isolated from the acidic and basic fraction respectively of an ethanol extract of the male flowers of Carica Papaya for the first time. It was collected from Bangladesh Agriculture Development Corporation, Gazipur. [ABSTRACT FROM AUTHOR]

The article focuses on the negative feasibility assessment for establishing a Biological Exposure Index (BEI) for 1-bromopropane, a chemical used in various industries, due to inadequate scientific data. Topics discussed include the call for additional data, the potential health risks associated with 1-bromopropane exposure, and the need for field or experimental studies to establish a BEI and improve risk management.

Background: Binge drinking can increase an individual's risk of developing alcohol use disorder (AUD). Ethanol targets multiple neurotransmitter systems; however, not much is known about its effects on the cholinergic system. Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels, the heteromeric α4β2 nAChR being a commonly expressed subtype. Desformylflustrabromine (dFBr), a positive allosteric modulator (PAM), increases the efficacy of α4β2 nAChR in vitro and has previously been shown to have translational potential. In this study, we investigated whether dFBr modulates the hypnotic response to ethanol.Methods: Ethanol-induced loss of righting reflex (LORR) duration was measured in the presence and absence of dFBr. The β2 nAChR selective antagonist dihydro-β-erythroidine (DHβE) was used to study the involvement of the β2 subunit. Additionally, we used a crosslinking-based western blot assay to estimate changes in total versus intracellular α4 nAChR protein in thalamic tissue of rats treated with vehicle, dFBr, ethanol, or ethanol and dFBr. Lastly, using Xenopus oocyte two-electrode voltage clamp (TEVC) studies, we determined the effects of ethanol and dFBr on α4β2 nAChR.Results: Pretreatment with 6 mg/kg dFBr reduced ethanol-induced LORR duration as compared to rats treated with ethanol alone. LORR studies with DHβE suggest that dFBr reduced ethanol-induced LORR duration via the β2 nAChR subunit. Crosslinking-based western analyses revealed that ethanol caused early increases in total and presumably surface thalamic α4 nAChR subunit protein levels. This ethanol-induced α4 nAChR upregulation was significantly reduced in rats pretreated with 6 mg/kg dFBr. In TEVC studies, ethanol potentiated ACh-induced currents in α4β2 nAChR, while it slightly reduced dFBr potentiation of maximal ACh currents.Conclusions: Our results suggest that thalamic nAChRs containing the α4 subunit are rapidly upregulated by a single intoxicating dose of ethanol. Furthermore, dFBr, an α4β2 nAChR-selective PAM, significantly attenuates the hypnotic response to ethanol via actions on β2 nAChR. Overall, these results indicate that dFBr represents an option to reverse ethanol intoxication. [ABSTRACT FROM AUTHOR]

Background: Less than two-thirds of children with abdominal pain in the emergency department receive analgesia. We sought to determine whether hyoscine butylbromide was superior to acetaminophen for children with nonspecific colicky abdominal pain.Methods: We randomly allocated children aged 8-17 years with nonspecific colicky abdominal pain who presented to the pediatric emergency department of London Health Sciences Centre, London, Ontario to receive hyoscine butylbromide, 10 mg given orally, or acetaminophen, 15 mg/kg given orally (maximum 975 mg). We considered the minimal clinically important difference for the primary outcome (self-reported pain at 80 min) to be 13 mm on a 100 mm visual analogue scale. Secondary outcomes included administration of rescue analgesia, adverse effects and pain score less than 30 mm at 80 minutes.Results: A total of 236 participants (120 in the hyoscine butylbromide group and 116 in the acetaminophen group) were included in the trial. The mean visual analogue scale scores at 80 minutes were 29 mm (standard deviation [SD] 26 mm) and 30 mm (SD 29 mm) with hyoscine butylbromide and acetaminophen, respectively (adjusted difference 1, 95% confidence interval -7 to 7). Rescue analgesia was administered to 4 participants (3.3%) in the hyoscine butylbromide group and 1 participant (0.9%) in the acetaminophen groups (p = 0.2). We found no significant differences in rates of adverse effects between hyoscine butylbromide (32/116 [27.6%]) and acetaminophen (28/115 [24.3]) (p = 0.5); no serious adverse effects were observed. The proportion with a pain score less than 30 mm at 80 minutes was 66 (55.0%) with hyoscine butylbromide and 63 (54.3%) with acetaminophen (p = 0.9).Interpretation: Hyoscine butylbromide was not superior to acetaminophen in this setting. Both agents were associated with clinically important pain reduction, and either can be considered for children presenting to the emergency department with nonspecific colicky abdominal pain. Trial registration: Clinicaltrials.gov, no. NCT02582307. [ABSTRACT FROM AUTHOR]

The article discusses the findings from a randomized clinical trial of prophylactic subcutaneous scopolamine butylbromide for the death rattle in patients at the end of life as indicated in the article published within the issue. Topics covered include the effectiveness of prophylactic subcutaneous scopolamine butylbromide, the design features of the trial that are exemplars for overcoming challenges regarding clinical trials of palliative care and the implications of the findings.

A new brominated polyacetylene xestonariene J (1), bearing a rare 2,4-dibromo-1-ene-3-yne terminal in the molecule, along with two known related analogues (2 and 3), was obtained from Chinese marine sponge Xestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and comparison with literature data. [ABSTRACT FROM AUTHOR]

Abstract Atmospheric fine particle (PM 2.5) samples were collected over a whole year (April 2016 - March 2017) across five sampling locations in the Beijing-Tianjin-Hebei (BTH) region, to investigate the occurrence of novel brominated flame retardants (NBFRs) and polybrominated diphenyl ethers (PBDEs). The concentrations of ∑ 9 NBFRs were in the range of 0.63–104 pg/m3 (15.6 ± 16.8 pg/m3) in atmospheric PM 2.5 , while the levels of ∑ 9 PBDEs (excluding BDE-209) ranged from 0.05 to 19.1 pg/m3 (2.9 ± 3.8 pg/m3) and BDE-209 concentrations ranged from 0.88 to 138 pg/m3 (22 ± 28 pg/m3). Relatively higher levels of NBFRs and PBDEs were found at urban sampling sites in Beijing City and Shijiazhuang City. Decabromodiphenylethane (DBDPE) and BDE-209 were the dominant compounds with the relative abundances of 72% in ∑ 9 NBFRs and 90% in ∑ 10 PBDEs, respectively. Generally, the levels of most target BFRs in summer were lower than those in other seasons. However, there were no notable seasonal differences in levels of DBDPE and BDE-209 in atmospheric PM 2.5 samples across the BTH region. Significant and positive correlations were found between the concentrations of BFRs and PM 2.5. Daily human exposure via inhalation revealed that children have a higher probability of suffering from the adverse effects of BFRs than that of adults. In addition, residents living near sampling locations across the BTH region may suffer high exposure risks to BDE-209 and NBFRs. Highlights • PM 2.5 -bound NBFRs were comprehensively investigated in the BTH region, China. • Relatively lower concentrations of PM 2.5 -bound NBFRs were found in summer. • PM 2.5 was the main driver of NBFRs distribution in different seasons and areas. • Children may suffer more from the adverse effects of BFRs. [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs) were measured in 182 sediments from the Huron–Erie Corridor, North America. The median (5–95 percentile) Corridor ∑PBDE concentration was 1.03 ng/g dry wt (0.25–13.48 ng/g dry wt). Dry weight ∑PBDEs were elevated in U.S. waters of the Detroit River (US DR) and lowest in Canadian waters of Lake St. Clair (CA LSC). Sediment total organic carbon (TOC) explained some of the variation in ∑PBDEs, particularly in upstream waterbodies except for the Detroit River where local sources were apparent in the US DR and TOC-dilution occurred in CA DR. Canadian Federal Sediment Quality guidelines were exceeded at 19 stations, 14 occurring in the US DR. ∑Hazard Quotients (∑HQ) had a median (5–95 percentile) Corridor value of 0.46 (ND to 2.27). By strata, 43.2% of US DR stations had ∑HQ's greater than 1 while 21.3% of US SCR stations exceeded a value of 1. [ABSTRACT FROM AUTHOR]

Sediments are known to be the ultimate sink for most pollutants in the aquatic environment. In this study, the concentrations of both legacy polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs) were measured in sediments samples from the Vaal River catchment. The concentrations of Σ7BDE-congeners ranged from 20 to 78 ng g−1 dry weight (dw) with BDE-209, -99, and -153 as the dominant congeners. The concentrations observed ranged from 9.4-56, 4-32, and 1-10.6 ng g−1 for BDE-209, -99, and -153, respectively. The concentrations of AHFRs, mainly contributed by decabromodiphenyl ethane (DBDPE) at approximately 95% of total AHFRs, ranged from 64 to 359 ng g−1 dw while the concentration of polybrominated biphenyls (PBBs), mainly PBB-209, ranged from 3.3-7.1 ng g−1 dw. The ratios of AHFRs to PBDEs observed in this study were 0.76, 1.17, and 7.3 for 2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate and bis-(2-ethylhexyl)-tetrabromophthalate (EH-TBB & BEH-TEBP)/penta-BDE; 1,2-bis-(2,4,6-tribromophenoxy) ethane (BTBPE)/octa-BDE; and DBDPE/BDE209, respectively. These results indicate dominance of some AHFRs compared to PBDEs. Our results indicates that BDE-99 poses high risk (RQ > 1) while BDE-209 posed medium risk (0.1 < RQ < 1). Though the concentration of DBDPE was several orders of magnitude higher than BDE209, its ecological risk was found to be negligible (RQ < 0.01). Thus, more attention is required to regulate the input (especially the e-waste recycling sites) of brominated flame retardants into the environment. [ABSTRACT FROM AUTHOR]

Abstract Brominated flame retardants (BFRs) are bromine-bearing hydrocarbons added or applied to materials to increase their fire resistance. As thermal treatment and recycling are common disposal methods for BFR-laden objects, it is essential to precisely describe their decomposition chemistry at elevated temperatures pertinent to their thermal recycling. Laboratory-level and pilot-scale investigations have addressed the thermal decomposition of pure BFRs and/or BFR-laden polymers under oxidative and pyrolytic environments, typically at temperatures of 280–900°C. These studies shed light on the effects of various factors influencing the decomposition behaviour of BFRs such as chemical character, polymer matrix, residence time, bromine input, oxygen concentration, and temperature. Although BFRs decomposition mainly occurs in a condensed phase, gas phase reactions also contribute significantly to the overall decomposition of BFRs. Exposing BFRs to temperatures higher than their melting points results in evaporation. Quantum chemical calculations have served to provide mechanistic and kinetic insights into the chemical phenomena operating in decomposition of BFRs and subsequent emissions of polybrominated dibenzo- p -dioxins and dibenzofurans (PBDD/Fs). Under thermal conditions such as smouldering, municipal waste incineration, pyrolysis, thermal recycling, uncontrolled burning and fires, BFRs degrade and form brominated products of incomplete combustion (BPICs). Thermal degradation of BFRs often proceeds in the presence of bromine atoms which inhibit complete combustion. Major BPICs comprise brominated benzenes and phenols in addition to a wide range of brominated aromatics. Pyrolytic versus oxidative conditions seems to have very little influence on the thermal stability and decomposition behaviour of commonly-deployed BFRs. Thermal degradation of BFRs produces potent precursors to PBDD/Fs. Experimental studies have established inventories of PBDD/F emissions with alarming high yields for many BFRs. Co-combustion of BFRs-containing objects with a chlorine source (e.g. polyvinyl chlorides) results in the emission of significant concentrations of mixed halogenated dibenzo- p -dioxins and dibenzofurans (i.e. PXDD/Fs). Formation of PBDD/Fs from incomplete BFRs decomposition occurs primarily due to the condensations of gas phase precursors, including unaltered structural entities of some BFRs in their own right. Complete destruction of BFRs promotes PBDD/Fs formation via de novo synthesis. Bromination of PBDD/Fs in gas phase reactions is more prevalent if compared with chlorination mechanisms of PCDD/Fs, which is largely dominated by heterogeneous pathways. In uncontrolled burning and in simulated fly ash experiments, a strong correlation between congeners patterns of polybrominated diphenyl ethers (PBDEs) and PBDD/Fs indicate that PBDEs function as direct precursors for PBDD/Fs, even in the de novo synthesis route. In this review, we critically discuss current literature on BFRs thermal decomposition mechanisms; gather information regarding the contribution of homogenous and heterogeneous routes to overall BFRs decomposition; survey all studies pertinent to the emission of PBDD/Fs and their analogous mixed halogenated counterparts from open burning of e-waste, and finally, highlight knowledge gaps and potential directions that warrant further investigations. [ABSTRACT FROM AUTHOR]

Two brominated bisamides were developed by this protocol. Compounds were synthesized either by 4-bromobenzoyl chloride and ethylenediamine or by ortho-phenylenediamine. The choice of the diamine led to the desired products, which were characterized by IR, 1 H NMR, 13 C NMR and XRD techniques. Compounds were applied to the Suzuki coupling. They were efficient for bromides with activating and deactivating substituent groups. In the reaction performed at low temperature and in short time, with yields over 95%, it was fundamental to choose the palladium source. [ABSTRACT FROM AUTHOR]

We investigated the occurrence of halogenated flame retardants (HFRs) including polybrominated diphenyl ethers (PBDEs), six novel brominated flame retardants (NBFRs) and dechlorane plus in air and soils on the eastern slope of Mt. Gongga on the eastern Tibetan Plateau. We detected all of the NBFR except bis(2-ethylhexyl)-tetrabromophthalate and pentabromoethyl benzene. NBFRs constituted the most prevalent group. BDE-28 and BDE-47 dominated among the PBDE congeners. Decabromodiphenyl ethane was detected at relatively high levels up to 171 pg/m3 and 1450 pg/g dry weight in air and soils, respectively; however, it appeared to be easily degraded in the environment. A general decreasing trend was observed among the HFR concentrations with increasing altitude, and this was due to the prominent contribution of source emissions over possible influence of environmental conditions. This study also suggests that HFRs are supplied to forest soils mainly in the form of precipitation and retained in the O horizon layers. [ABSTRACT FROM AUTHOR]

Reliable quantifications of brominated flame retardants (BFRs) not only ensure compliance with laws and regulations on the use of BFRs in commercial products, but also is key for accurate risk assessments of BFRs. Acetone is a common solvent widely used in the analytical procedure of BFRs, but our recent study found that acetone can react with some BFRs. It is highly likely that such reactions can negatively affect the quantifications of BFRs in environmental samples. In this study, the effects of acetone on the extraction yields of three representative BFRs [i.e., decabrominated diphenyl ether (decaBDE), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA)] were evaluated in the Soxhlet extraction (SE) system. The results showed that acetone-based SE procedure had no measureable effect for the recovery efficiencies of decaBDE but could substantially lower the extraction yields for both TBBPA and HBCD. After 24 h of extraction, the recovery efficiencies of TBBPA and HBCD by SE were 93 and 78% with acetone, 47 and 70% with 3:1 acetone:n-hexane, and 82 and 94% with 1:1 acetone:n-hexane, respectively. After 72 h of extraction, the extraction efficiencies of TBBPA and HBCD decreased to 68 and 55% with acetone, 0 and 5% with 3:1 acetone/n-hexane mixtures, and 0 and 13% with 1:1 acetone/n-hexane mixtures, respectively. The study suggested that the use of acetone alone or acetone-based mixtures should be restricted in the quantitative analysis of HBCD and TBBPA. We further evaluated nine alternative solvents for the extraction of the three BFRs. The result showed that diethyl ether might be reactive with HBCD and may not be considered as the alternative to acetone used solvents for the extraction of HBCD. [ABSTRACT FROM AUTHOR]

Abstract: Replacing pure inorganic materials by functional organic–inorganic hybrid ones to lower production costs has become a major challenge, in particular for the optoelectronic industry. Adding nanostructuration abilities meanwhile preserving homogeneity is even more challenging for this class of new materials. Here we show that red‐NIR emissive ternary molybdenum cluster salts can be assembled to liquid crystalline 15C5 crown ethers. The resulting hybrids are homogeneous and stable up to high temperature despite the weakness of the supramolecular interactions binding both components. These are illustrated by 133Cs MAS NMR. All hybrids show hexagonal columnar arrangements and strong red‐NIR emission. Surprisingly, when chlorinated clusters are used instead of brominated ones, the mesophase stability is largely enhanced. [ABSTRACT FROM AUTHOR]

The estrogen agonistic/antagonistic activity of 16 brominated by-products of parabens was assessed by using a yeast two-hybrid assay transfected with the human estrogen receptor α. Characterization of synthetic compounds including novel brominated parabens was performed using 1H-NMR spectroscopy and high-resolution mass spectrometry. For the agonist assay, five C3-C4 alkylparabens exhibited significant activity (P < 0.05) relative to that of 17β-estradiol, ranging from 3.7 × 10−5 to 7.1 × 10−4. In contrast, none of the brominated alkyl parabens exhibited agonistic activity. In the antagonist assay, 12 brominated alkylparabens and butylparaben exhibited significant antagonistic activity (P < 0.05). Their antagonistic activity relative to 4-hydroxytamoxifen ranged from 0.11 to 2.5. The antagonist activity of C1-C4 alkylparabens increased with the number of bromine substitutions. Benzylparaben exhibited both agonistic and antagonistic activity, and these activities dissipated or were weakened with increased bromination. Thus, increased bromination appeared to attenuate the estrogen agonistic activity of most parabens such that it resulted in increased antagonistic activity, a feature of parabens that had not been previously described. [ABSTRACT FROM AUTHOR]

We explored whether polybrominated diphenyl ethers (PBDEs) exposed in cord blood could have any potential relationship with perinatal outcomes. Participants were pregnant females (n = 222) who were recruited from a prospective birth cohort (Laizhou Wan Birth Cohort, LWBC) between September 2010 and February 2012. We measured eight PBDE congeners (BDE-28, BDE-47, BDE-85, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) in cord serum and examined their relationship with perinatal outcomes. The median levels of BDE-28, BDE-47, BDE-85, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183 were 2.92, 3.93, 2.29, 7.03, 3.03, 3.14, 1.46, and 2.55 ng/g lipids, respectively. For each log unit increase in BDE-47, BDE-100, and ∑4PBDEs, gestational age increased by 0.70 weeks (95% confidence interval [CI] 0.25, 1.15), 0.48 weeks (95% CI 0.03, 0.94), and 0.73 weeks (95% CI 0.12, 1.34), respectively. We also found that BDE-47 was positively associated with head circumference (β = 0.42, 95% CI 0.00, 0.84). Given that our study area is one of the major brominated flame retardant production areas in China, and the cord PBDEs levels were relatively higher than those reported in most other Asian areas, more studies on the effects of in utero PBDE exposure on fetal growth and child development are warranted. [ABSTRACT FROM AUTHOR]

Indoor dust is considered an important human exposure route to flame retardants (FRs), which has arised concern due the toxic properties of some of these substances. In this study, ten organophosphorus flame retardants (OPFRs), eight polybrominated diphenyl ethers (PBDEs) and four new brominated flame retardants (NBFRs) were determined in indoor dust from different places in Araraquara-SP (Brazil). The sampled places included houses, apartments, offices, primary schools and cars. The analysis of the sample extracts was performed by gas chromatography coupled to mass spectrometry and two ionization techniques were used (electron ionization – EI; electron capture negative ionization – ECNI). OPFRs were the most abundant compounds and tris(2-butoxyethyl) phosphate (TBOEP), tris(phenyl) phosphate (TPHP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP) were present at the highest concentrations. Among the brominated FRs, the most ubiquitous compounds were BDE-209, bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP) and decabromodiphenyl ethane (DBDPE). Statistical analysis revealed that there were differences among dust typologies for TBOEP, TDCIPP, ethylhexyl diphenyl phosphate (EHDPHP), BDE-209, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB), BEH-TEBP and DBDPE, which were attributed to different construction materials in each particular environment and to the age of the buildings. The highest levels of brominated FRs were observed in offices, TBOEP was at high concentration in primary schools, and TDCIPP was at high concentration in cars. A preliminary risk assessment revealed that toddlers were exposed to TBOEP levels higher than the reference dose when considering the worst case scenario. The results obtained in this study showed for the first time that although Brazil does not regulate the use of FRs, these substances are present in indoor dust at levels similar to the observed in countries that have strict fire safety standards, and that humans are exposed to complex mixtures of these contaminants via indoor dust. [ABSTRACT FROM AUTHOR]

Luminescent facial tris -cyclometallated iridium complexes of generic structure Ir(L) 2 (dbppy) with one 2-(4-bromophenyl)-5-bromopyridyl (dbppy) ligand {where L represents the cyclometallating ligands [2-phenylpyridyl (ppy), 2-(4,6- difluorophenyl)pyridyl] (dfppy), [1-phenylpyrazole] (ppz) or [1-(4,6-difluorophenyl)pyrazole] (dfppz)} were synthesized. The bromine substituents allow the further incorporation of the iridium complexes into a polyaryl backbone. The route starts from μ-chloro-bridged dimers L 2 Ir(μCl) 2 IrL 2 . Further reaction of these precursors with an excess of dbppyH at temperatures of 95–120 °C leads to the target complexes only in the case of the phenylpyridine based precursors (L = ppy and dfppy). All complexes were characterized via 1D and 2D NMR spectroscopic methods. All the facial tris -cyclometallated complexes exhibited strong absorptions between 200 and 320 nm typical of a π → π ∗ transition together with weaker MLCT absorptions below 320 nm. The emission spectra of all these luminescent Ir(III)-complexes cover the region between approximately 500 to 700 nm. This strongly supports the hypothesis that the luminescent properties are controlled mainly by the dbppy ligand. The lifetimes of the complexes are quite different relative to each other and are much shorter than their homoleptic Ir(L) 3 counterparts. [ABSTRACT FROM AUTHOR]

Samples of plastic collected from two beaches in southwest England ( n  = 185) have been analysed by XRF spectrometry for elements that are hazardous or restricted in synthetic polymers (namely, As, Ba, Br, Cd, Cr, Hg, Pb, Sb and Se). Overall, one or more restricted element was detected in 151 samples, with 15 cases exhibiting non-compliance with respect to the Restriction of Hazardous Substances (RoHS) Directive. Twelve plastics that were RoHS-non-compliant were subsequently processed into microplastic-sized fragments and subjected to an avian physiologically-based extraction test (PBET) that simulates the chemical conditions in the gizzard-proventriculus of the northern fulmar. Kinetic profiles of metal and metalloid mobilisation in the PBET were fitted using a pseudo-first-order diffusion model with rate constants ranging from ∼0.02 to 0.5 h −1 , while profiles for Br were better fitted with a parabolic diffusion model and rate constants of 7.4–9.5 (μg L −1 ) −1 h −1/2 . Bioaccessibilities, based on maximum or equilibrium concentrations mobilised relative to total (XRF) concentrations, ranged from <1% for Cd and Se in polyethylene and polypropylene to over 10% for Br in a sample of expanded polystyrene and Pb in a sample of PVC. Calculations suggest that ingested plastic could contribute about 6% and 30% of a seabird's exposure to and accumulation of Pb and brominated compounds, respectively. [ABSTRACT FROM AUTHOR]

Experimental and theoretical studies showed the differences observed in the benzylic tetrabromination reactions in 2,5-dimethylterephthalonitrile compared to 1,4-dimethylbenzene. It was observed that the compound containing the nitrile substituent underwent a slower bromination reaction, with the formation of four intermediate compounds, while for the compound without substituents, the reaction was faster and only two intermediate compounds were observed. [ABSTRACT FROM AUTHOR]

The quality of indoor environments has a significant impact on public health. Usually, an indoor environment is treated as a static box, in which physicochemical reactions of indoor air contaminants are negligible. This results in conservative estimates for primary indoor air pollutant concentrations, while also ignoring secondary pollutants. Thus, understanding the relationship between indoor and outdoor particles and particle-bound pollutants is of great significance. For this reason, we collected simultaneous indoor and outdoor measurements of the size distribution of airborne brominated flame retardant (BFR) congeners. The time-dependent concentrations of indoor particles and particle-bound BFRs were then estimated with the mass balance model, accounting for the outdoor concentration, indoor source strength, infiltration, penetration, deposition and indoor resuspension. Based on qualitative observation, the size distributions of ΣPBDE and ΣHBCD were characterized by bimodal peaks. According to our results, particle-bound BDE209 and γ -HBCD underwent degradation. Regardless of the surface adsorption capability of particles and the physicochemical properties of the target compounds, the concentration of BFRs in particles of different size fractions seemed to be governed by the particle distribution. Based on our estimations, for airborne particles and particle-bound BFRs, a window-open ventilated room only takes a quarter of the time to reach an equilibrium between the concentration of pollutants inside and outside compared to a closed room. Unfortunately, indoor pollutants and outdoor pollutants always exist simultaneously, which poses a window-open-or-closed dilemma to achieve proper ventilation. [ABSTRACT FROM AUTHOR]

The KMnO 4 degradation of decabromodiphenyl ethane (DBDPE), an additive in brominated flame retardants (BFRs), was investigated in a sulfuric acid system. The degradation tests showed that DBDPE reacted completely with KMnO 4 in sulfuric acid, and a removal rate of 99.71% seems realistic. Many products were detected by liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-Q-TOF-MS) analysis and gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) analysis. The degradation initially forms 1,2-bis(perbromophenyl)ethane-1,2-dione (P 1 ), pentabromophenol (P 2 ), 2-(perbromophenyl)ethanol (P 3 ) and pentabromobenzoic acid (P 28 ), and the subsequent transformation of these primary intermediates generates ring-opening, five-membered ring and six-membered heterocycle products over time. Two main reaction pathways involving the direct oxidation of the C–C bond of the ethyl group and the cleavage of the C–C bond between ethyl carbon and the adjacent carbon were proposed, and were further confirmed by point charges analyses and Wiberg bond order calculations. Furthermore, the toxicity of DBDPE and its degradation products were evaluated using the ECOSAR program. DBDPE was found to be a toxic substance that could cause great damage to three kinds of organisms in different trophic levels, while all the transformation products were less toxic than parent compound. [ABSTRACT FROM AUTHOR]

Background: Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels. The α4β2 subtype of nAChRs plays an important role in the mediation of pain and several nicotine-evoked responses. Agonists and partial agonists of α4β2 nAChRs show efficacy in animal pain models. In addition, the antinociceptive properties of nicotine, a non-selective nAChR agonist with a high affinity for α4β2 nAChRs, is well-known. There is a growing body of evidence pointing to allosteric modulation of nAChRs as an alternative treatment strategy in experimental pain. Desformylflustrabromine (dFBr) is a positive allosteric modulator (PAM) at α4β2 nAChRs that enhances agonist responses without activating receptors. We hypothesized that dFBr may enhance nicotine-induced antinociception.Methods: The present study investigated whether dFBr could attenuate mouse chronic constriction injury (CCI)-induced neuropathic pain by increasing endogenous cholinergic tone or potentiating the nicotine-evoked antiallodynic response.Results: We found that subcutaneous administration of dFBr failed to reduce pain behaviour on its own. However, the combination of dFBr with nicotine significantly reversed neuropathic pain behaviour dose- and time-dependently without motor impairment. Our data revealed that this effect was mediated by the α4β2 nAChRs by using competitive α4β2 antagonist dihydro-β-erythroidine. In addition, dFBr failed to potentiate the antiallodynic effect of morphine, which shows the effect of dFBr is unique to α4β2 nAChRs.Conclusions: The present results suggest that allosteric modulation of α4β2 nAChR may provide new strategies in chronic neuropathic pain.Significance: α4β2 nAChRs are involved in pain modulation. dFBr, a PAM at α4β2 nAChRs, potentiates the nicotine response dose-dependently in neuropathic pain. Thus, the present results suggest that allosteric modulation of α4β2* nAChR may provide new strategies in chronic neuropathic pain. [ABSTRACT FROM AUTHOR]

Solvent additives have been considered as a simple and efficient method to increase the performance of bulk-heterojunction (BHJ) organic solar cells, in which, the morphology of the active layer could obtain further improvements by using the binary solvent additives. In this paper, a series of brominated compounds, 1-Bromo-4-butylbenzene (Brbb), 1-Bromo-4- n -hexylbenzene (Brbh) and 1-Bromo-4- n -octylbenzene (Brbo), have been respectively incorporated with 1, 8-diiodooctane (DIO) and regarded as binary solvent additives to fabricate highly efficient bulk heterojunction (BHJ) organic solar cells (OSCs). Compared with the BHJ film based on single additive, the binary additives contained BHJ film shows increased optical absorption, efficient charge transport and better active layer morphology, leading to an enhancement of short-circuit current (J SC ) together with a higher achieved fill factor (FF). The conventional BHJ device using PTB7: PC 71 BM or PTB7-th: PC 71 BM with the binary solvent additives exhibit enhanced PCE of 8.13% and 10.31%, respectively, which is much higher than that of single additive based devices (7.04% for PTB7 and 8.73% for PTB7-th). The optimized performance of BHJ devices indicates that these brominated compounds are promising additives to improve device efficiency. [ABSTRACT FROM AUTHOR]

Activated carbon injection is a proven technology to capture mercury from flue gases. Due to the high cost and environmental concerns related to its disposal, high efficiency and low-cost sorbents have been studied to replace activated carbon. In this study, the petroleum coke obtained from two Canadian petroleum refineries, with high inherent sulfur content and impregnated with bromine, was compared to investigate elemental mercury capture mechanisms. These carbon-based sorbents showed excellent mercury removal efficiency at 100 and 200 °C. Elemental analysis, Brunauer–Emmett–Teller surface area, pore volume and thermogravimetric analysis were used to characterize the sorbents. X-ray photoelectron spectroscopy was used to examine the significant changes in chemistry and oxidation states of Br, S and Hg on the sorbent surface. More active mercury binding sites were created on brominated petroleum cokes after the chemical-mechanical bromination process. The inherent thiophene and organic sulfide in petroleum coke played a dominant role in mercury capture. [ABSTRACT FROM AUTHOR]

Degradation of brominated flame retardants present in printed circuit boards (PCBs) was tested using subcritical water in a high pressure reactor. Debromination experiments were carried out in a batch stirred reactor at three different temperatures (225 °C, 250 °C and 275 °C) keeping a solid to liquid (S/L) ratio of PCB:water = 1:5 during 180 min. Results indicated that debromination efficiency was increased with temperature (18.5–63.6% of bromine present in the original PCB was removed). Thermal decomposition of the debrominated materials was studied and compared with that of the original PCB. Thermogravimetric analyses were performed at three different heating rates (5, 10 and 20 K min −1 ), studying both the pyrolysis (inert atmosphere) and combustion (in air). Pyrolysis runs of the debrominated materials were also performed in a quartz horizontal laboratory furnace at 850 °C, in order to study the emission of pollutants. More than 99% of the bromine was emitted in the form of HBr and Br 2 . Emissions of polycyclic aromatic hydrocarbons (PAHs) and bromophenols (BrPhs) decreased with the increase in the treatment temperature; naphthalene (10,800–18,300 mg kg −1 original sample) and monobrominated phenols (12.8–16.9 mg kg −1 original sample) were the most abundant compounds. [ABSTRACT FROM AUTHOR]

Recently, traces of brominated flame retardants (BFRs) have been detected in black plastic food-contact materials (FCMs), indicating the presence of recycled plastics, mainly coming from waste electric and electronic equipment (WEEE) as BFRs are one of the main additives in electric applications. In order to evaluate efficiently and preliminaryin situthe presence of WEEE in plastic FCMs, a generic procedure for the evaluation of WEEE presence in plastic FCMs by using defined parameters having each an associated importance level has been proposed. This can be achieved by combining parameters like overall bromine (Br) and antimony (Sb) content; additive and reactive BFR, rare earth element (REE) and WEEE-relevant elemental content and additionally polymer purity. In most of the cases, the WEEE contamination could be confirmed by combining X-ray fluorescence (XRF) spectrometry and thermal desorption/pyrolysis gas chromatography-mass spectrometry (GC-MS) at first. The Sb and REE content did not give a full confirmation as to the source of contamination, however for Sb the opposite counts: Sb was joined with elevated Br signals. Therefore, Br at first followed by Sb were used as WEEE precursors as both elements are used as synergetic flame-retardant systems. WEEE-specific REEs could be used for small WEEE (sWEEE) confirmation; however, this parameter should be interpreted with care. The polymer purity by Fourier-transform infrared spectrometer (FTIR) and pyrolysis GC-MS in many cases could not confirm WEEE-specific contamination; however, it can be used for purity measurements and for the suspicion of the usage of recycled fractions (WEEE and non-WEEE) as a third-line confirmation. To the best of our knowledge, the addition of WEEE waste to plastic FCMs is illegal; however, due to lack on screening mechanisms, there is still the breakthrough of such articles onto the market, and, therefore, our generic procedure enables the quick and effective screening of suspicious samples. [ABSTRACT FROM AUTHOR]

This study describes the development and validation of a sensitive and reliable method for determination of polybrominated diphenyl ethers (PBDEs) in atmospheric particulate matter using selective pressurized liquid extraction (SPLE) and gas chromatography-mass spectrometry with a negative chemical ionization (GC-NCI-MS). Extraction and clean-up were performed using PLE with 2 g florisil and 3 g silica placed in the extraction cells. Under optimal conditions, 14 PBDEs were extracted at 70 °C using hexane/dichloromethane (50:50, v/v) as solvent. Validation of SPLE returned excellent recoveries for most analytes, with relative standard deviations mostly below 20%. Method detection limits ranged from 0.13 to 15.38 ng·mL for the GC-MS analyses. The method was successfully applied to atmospheric particulate matter of Beijing, where analytes were detected in the range of 182.79 to 468.99 pg·m. [ABSTRACT FROM AUTHOR]

Commonly, analytical methods measuring brominated flame retardants (BFRs) of different chemical polarities in human serum are labor consuming and tedious. Our study used acidified diatomaceous earth as solid-phase extraction (SPE) adsorbent and defatting material to simultaneously determine the most abundant BFRs and their metabolites with different polarities in human serum samples. The analytes include three types of commercial BFRs, tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) isomers, and polybrominated biphenyl ethers (PBDEs), and dominant hydroxylated BDE (OH-PBDE) and methoxylated BDE (MeO-PBDE) metabolites of PBDEs. The sample eluents were sequentially analyzed for PBDEs and MeO-BDEs on online gel permeation chromatography/gas chromatography-electron capture-negative ionization mass spectrometry (online GPC GC-ECNI-MS) and for TBBPA, HBCD, and OH-BDEs on liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method recoveries were 67-134% with a relative standard deviation (RSD) of less than 20%. Method detection limits (MDLs) were 0.30-4.20 pg/mL fresh weight (f.w.) for all analytes, except for BDE-209 of 16 pg/mL f.w. The methodology was also applied in a pilot study, which analyzed ten real samples from healthy donors in China, and the majority of target analytes were detected with a detection rate of more than 80%. To our knowledge, it is the first time for us in effectively determining BFRs of most types in one aliquot of human serum samples. This new analytical method is more specific, sensitive, accurate, and time saving for routine biomonitoring of these BFRs and for integrated assessment of health risk of BFR exposure. [ABSTRACT FROM AUTHOR]

Profiles, sources and potential exposures of chlorinated and brominated polycyclic aromatic hydrocarbons (ClPAHs and BrPAHs) in haze associated atmosphere remain unclear. Haze events happened frequently during heating period in Beijing provided a typical urban context to investigate the concentrations, profiles, sources and potential exposures of ClPAHs, BrPAHs and their non-halogenated parent compounds (PAHs) in air samples. Average concentrations of PAHs, ClPAHs and BrPAHs during heating periods (with more frequent haze events) were about 3–9 times higher than during non-heating periods. Concentrations of particulate matter (PM)-associated ClPAHs and BrPAHs were higher in heating period than in non-heating period, while for gas-associated ClPAHs and BrPAHs, this distinction was not significant. Congener patterns and congener profiles indicated that with increasing coal combustion during the heating period, concentrations of PAHs and ClPAHs in air were elevated in comparison to the non-heating period. Inhalation of PM-associated PAHs, ClPAHs and BrPAHs accounted for higher exposure than inhalation of gas phase and dermal contact of both gas phase and particulate phase. In this study we found that the particulate phase is the dominant exposure pathway of atmospheric PAHs, ClPAHs and BrPAHs during haze days, which is different from previous studies. [ABSTRACT FROM AUTHOR]

The aim of this work is the identification of mild reaction conditions for the Blaise-type transformation of brominated β-keto esters with nitriles to generate enamino-substituted keto esters. The best results were obtained when a combination of indium metal (0.7 equiv.) with indium trichloride (1.6 equiv.) were applied at 60 °C for 20 to 72 hours, and these conditions could be applied to a broad range of nitriles and a significant number of different β-keto esters. The transformation of ali-phatic nitriles proved to be difficult and gave only moderate yields. However, aromatic nitriles gave good yields in many cases. The applicability range of β-keto esters is acceptable while some electron-deficient aryl-substituents on the keto ester were challenging substrates. Nevertheless, we were able to expand the scope of the Blaise-type reaction towards brominated β-keto esters significantly. [ABSTRACT FROM AUTHOR]

BACKGROUND: Prior studies suggest neurodevelopmental impacts of polybrominated diphenyl ethers (PBDEs), but few have examined diagnosed developmental disorders. OBJECTIVES: Our aim was to determine whether prenatal exposure to brominated flame retardants (BFRs) is associated with autism spectrum disorder (ASD) or intellectual disability without autism (ID). METHODS: We conducted a population-based case-control study including children with ASD (n=545) and ID (n=181) identified from the California Department of Developmental Services and general population (GP) controls (n=418) from state birth certificates. ASD cases were matched to controls by sex, birth month, and birth year. Concentrations of 10 BFRs were measured in maternal second trimester serum samples stored from routine screening. Logistic regression was used to calculate crude and adjusted odds ratios (AOR) for associations with ASD, and separately for ID, compared with GP controls, by quartiles of analyte concentrations in primary analyses. RESULTS: Geometric mean concentrations of five of the six congeners with ≥55% of samples above the limit of detection were lower in mothers of children with ASD or ID than in controls. In adjusted analyses, inverse associations with several congeners were found for ASD relative to GP (e.g., quartile 4 vs. 1, BDE-153: AOR=0:56, 95% CI: 0.38, 0.84). When stratified by child sex (including 99 females with ASD, 77 with ID, and 73 with GP), estimates were consistent with overall analyses in boys, but in the opposite direction among girls, particularly for BDE-28 and -47 (AOR=2:58, 95% CI: 0.86, 7.79 and AOR=2:64, 95% CI: 0.97, 7.19, respectively). Similar patterns overall and by sex were observed for ID. CONCLUSIONS: Contrary to expectation, higher PBDE concentrations were associated with decreased odds of ASD and ID, though not in girls. These findings require confirmation but suggest potential sexual dimorphism in associations with prenatal exposure to BFRs. [ABSTRACT FROM AUTHOR]

Brominated hydrocarbons are a typical pollutant in purified terephthalic acid (PTA) exhaust gas, which is harmful for human health and the environment once released to the atmosphere. In this study, three Co 3 O 4 /CeO 2 catalysts with different CeO 2 morphologies (rod, plate, and cube) were prepared and were used for low temperature dibromomethane (CH 2 Br 2 ) oxidation, which was used as the model compound for brominated hydrocarbons. The experimental results showed that Co 3 O 4 /CeO 2 -rod achieved significantly higher catalytic activity, with a T-90 of approximately 312 °C for CH 2 Br 2 oxidation and higher selectivity to CO 2 than Co 3 O 4 /CeO 2 -plate and Co 3 O 4 /CeO 2 -cube. All of the Co 3 O 4 /CeO 2 catalysts investigated were stable for at least 30 h at 500 ppm CH 2 Br 2 and 10% O 2 at a GHSV of 75,000 mL/(g·h) −1 , and the final products were CO x , Br 2 , and HBr, without the formation of other Br-containing organic byproducts. The higher catalytic activity of Co 3 O 4 /CeO 2 -rod was attributed to the high content of Co 3+ , more surface-adsorbed oxygen, and more oxygen vacancies in their exposed {1 0 0} and {1 1 0} planes. In addition, Co 3 O 4 had a stronger interaction with CeO 2 -rod, making it superior for CH 2 Br 2 oxidation. Moreover, on the basis of the analysis of products and in situ DRIFTS studies, a credible reaction mechanism for CH 2 Br 2 oxidation over Co 3 O 4 /CeO 2 catalysts was proposed. [ABSTRACT FROM AUTHOR]

The inhibitory effects of five novel brominated flame retardants, 1,2-bis(2,4,5-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP), and β-tetrabromoethylcyclohexane (β-TBECH), on thyroid hormone deiodinase (DIO) and sulfotransferase (SULT) activity were investigated using human in vitro liver microsomal and cytosolic bioassays. Enzymatic activity was measured by incubating active human liver subcellular fractions with thyroid hormones (T4 and rT3 separately) and measuring changes in thyroid hormone (T4, T3, rT3, and 3,3'-T2) concentrations. Only DBDPE showed inhibition of both outer and inner ring deiodination (O and IRD) of T3 and 3,3'-T2 formation from T4, respectively, with an estimated IC50 of 160 nM; no statistically significant inhibition of SULT activity was observed. ORD inhibition of 3,3'-T2 formation from rT3 was also observed (IC50 ~ 100 nM). The kinetics of T4 O and IRD were also investigated, although a definitive mechanism could not be identified as the Michaelis-Menten parameters and maximal rate constants were not significantly different. Concentrations tested were intentionally above expected environmental levels, and this study suggests that these NBFRs are not potent human liver DIO and SULT inhibitors. To our knowledge, DBDPE is the first example of a nonhydroxylated contaminant inhibiting DIO activity, and further study of the mechanism of action is warranted. [ABSTRACT FROM AUTHOR]

There has been increasing recognition of the occurrence of natural, halogenated organic compounds in marine and terrestrial environments. Chloroform is an example of a halogenated organic compound with natural formation as its primary source. Chloroform emission from soil has been reported from diverse Arctic, temperate, and (sub)tropical ecosystems. The terrestrial environment is a significant source to the atmosphere, but little is known about the formation pathway of chloroform in soil. Here, we present evidence that chloroform is formed through the hydrolysis of trichloroacetyl compounds in natural, organic-rich soils. In situ emissions of chloroform from soil in nine Arctic and subarctic ecosystems were linked to soil trichloroacetyl turnover. The residence time from formation of the trichloroacetyl compounds in soil to the release of chloroform to the atmosphere varied between 1 and 116 active months in unfrozen topsoil, depending on soil pH. Nonspecific halogenation that leads to trihaloacetyl formation does not discriminate between chloride and bromide, and brominated analogues were formed alongside chloroform. Soil may therefore be a previously unrecognized, natural source of brominated haloforms. The formation pathway of haloforms through trihaloacetyl compounds can most likely be extended to other ecosystems with organic topsoils. [ABSTRACT FROM AUTHOR]

Polyurethane foam (PUF) disk passive samplers were deployed at one inland and two island locations in the Bothnian Bay region of the northern Baltic Sea. Uptake was linear over 81–147 d and a temperature range of −2.6 to 14.2 °C for organochlorine pesticides (OCPs) and current-use pesticides (CUPs) having log K OA ≥9 at ambient temperatures. Partial saturation of the PUF disks occurred for the more volatile OCPs hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), and for bromoanisoles (BAs), which are products of bromophenols released by natural and anthropogenic sources. Correction for nonlinear uptake of these was made using experimentally measured PUF-air partition coefficients. Passive-derived air concentrations of pesticides were uniform over the bay and agreed within a factor of 2 or better with levels determined by active (pumped) sampling at one of the island stations. Levels of OCPs were similar to those reported at background sites in the European and Canadian Arctic and at monitoring stations in the central Baltic and southern Scandinavia, indicating long-range transport. The insecticide chlorpyrifos was 10 times lower at bay stations than in the Canadian Arctic. Insight to sources and processes was gained by examining compound profiles. Fractions F alpha = α-HCH/(α-HCH + γ-HCH) and F TC = trans -chlordane/( trans -chlordane + cis -chlordane) at bay stations were higher than in the Norwegian and Finnish Arctic and similar to those at the southern monitoring stations. Volatilization of chlordanes from Baltic seawater may also modify F TC . Higher F TriBA = 2,4,6-TriBA/(2,4,6-TriBA + 2,4-DiBA) distinguished local volatilization from the Baltic Sea versus lower F TriBA found at the inland site and reported in air on the Norwegian coast, suggesting westerly transport from the Atlantic across Norway and Sweden. [ABSTRACT FROM AUTHOR]

We conducted this study to assess the occurrence, profiles, and toxicity of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs) in e-waste open burning soils (EOBS). In this study, concentrations of 15 PAHs, 26 Cl-PAHs and 14 Br-PAHs were analyzed in EOBS samples. We found that e-waste open burning is an important emission source of Cl-PAHs and Br-PAHs as well as PAHs. Concentrations of total Cl-PAHs and Br-PAHs in e-waste open burning soil samples ranged from 21 to 2800 ng/g and from 5.8 to 520 ng/g, respectively. Compared with previous studies, the mean of total Cl-PAH concentrations of the EOBS samples in this study was higher than that of electronic shredder waste, that of bottom ash, and comparable to fly ash from waste incinerators in Korea and Japan. The mean of total Br-PAH concentrations of the EOBS samples was generally three to four orders of magnitude higher than those in incinerator bottom ash and comparable to incinerator fly ash, although the number of Br-PAH congeners measured differed among studies. We also found that the Cl-PAH and Br-PAH profiles were similar among all e-waste open burning soil samples but differed from those in waste incinerator fly ash. The profiles and principal component analysis results suggested a unique mechanism of Cl-PAH and Br-PAH formation in EOBS. In addition, the Cl-PAHs and Br-PAHs showed high toxicities equivalent to PCDD/Fs measured in same EOBS samples when calculated based on their relative potencies to benzo[a]pyrene. Along with chlorinated and brominated dioxins and PAHs, Cl-PAHs and Br-PAHs are important environmental pollutants to investigate in EOBS. [ABSTRACT FROM AUTHOR]

2,4,6-Tribromophenol (TBP), an intermediate of brominated flame retardants, can easily release to environment and recalcitrant to degradation. Previously, Bacillus sp. GZT, a pure aerobic strain capable of simultaneously debrominating and mineralizing TBP, was successfully isolated by us. To further obtain a practical application and dig up its TBP degradation mechanism, a total of 46.7-fold purification of a novel dehalogenase with a final specific activity of 18.9 U mg −1 and a molecular mass of 63.4 kDa was achieved. Under optimal conditions (35 °C and 200 rpm), up to 80% degradation efficiencies were achieved within 120 min. Adding H 2 O 2 , NADPH, Mn 2+ and Mg 2+ promoted enzyme reaction effectively; while EDTA, methyl viologen, Ni 2+ , Cu 2+ , Ca 2+ and Fe 2+ strongly inhibited reaction activities. The debromination of TBP was catalyzed by the enzyme at a Km of 78 μM and a Vmax of 0.65 min −1 mg protein −1 , which indicated that this dehalogenase could specifically eliminate TBP with a high efficiency and stability. Based on MALDI-TOF/TOF analysis, the dehalogenase shared 98% identity with peptide ABC transporter substrate-binding protein. One open reading frame (ORF) encoding this peptide was found in Strain GZT genome, subjected to clone and expressed in Escherichia coli ( E. coli ) to characterize the encoding gene. Result showed that this recombinant strain could also remove as similar amount of TBP as Bacillus sp. GZT under the identical condition. Based on these results, we suggest that this newly-isolated TBP dehalogenase highlights a new approach for remediating TBP pollution. [ABSTRACT FROM AUTHOR]

A new, efficient and green protocol for the one-pot synthesis of α-bromoketones from secondary alcohols using cheap, air stable and non-toxic reagents such as NH4Br and oxone has been developed. This reaction proceeds via two consecutive steps such as oxidation of secondary alcohols and oxidative bromination of in situ generated ketones. [ABSTRACT FROM AUTHOR]

Hexabromocyclododecane (HBCD) is a brominated flame retardant used throughout the world. It has been detected in various environmental media and has been shown toxic to aquatic life. The toxic effects of HBCD to aquatic organisms in Chinese freshwater ecosystems are discussed here. Experiments were conducted with nine types of acute toxicity testing and three types of chronic toxicity testing. After comparing a range of species sensitivity distribution models, the optimal model of Bull III was used to derive the safety thresholds for HBCD. The acute safety threshold and the chronic safety threshold of HBCD for Chinese freshwater organisms were found to be 2.32 mg/L and 0.128 mg/L, respectively. Both values were verified by the methods of the Netherlands and the United States. HBCD was found to be less toxic compared to other widely used brominated flame retardants. The present results provide valuable information for revision of the water quality standard of HBCD in China. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hexabromocyclododecane (HBCD) is a high production volume brominated flame retardant added to building insulation foams, electronics, and textiles. HBCD is a commercial mixture (CM-HBCD) composed of three main stereoisomers: α-HBCD (10%), βHBCD (10%), and γ-HBCD (80%). A shift from the dominant stereoisomer γ-HBCD to α-HBCD is detected in humans and wildlife. OBJECTIVES: Considering CM-HBCD has been implicated in neurodevelopment and endocrine disruption, with expected metabolism perturbations, we performed metabolomics on mice serum obtained during a window-of-developmental neurotoxicity to draw correlations between early-life exposures and developmental outcomes and to predict health risks. METHODS: Six female C57BL/6 mice at postnatal day (PND) 10 were administered a single gavage dose of α-, γ-, or CM-HBCD at 3, 10, and 30 mg/kg. Nuclear magnetic resonance metabolomics was used to analyze 60 μL serum aliquots of blood collected 4 days post-oral exposure. RESULTS: Infantile mice exposed to α-, γ-, or CM-HBCD demonstrated differences in endogenous metabolites by treatment and dose groups, including metabolites involved in glycolysis, gluconeogenesis, lipid metabolism, citric acid cycle, and neurodevelopment. Ketone bodies, 3-hydroxybutyrate, and acetoacetate, were nonstatistically elevated, when compared with mean control levels, in all treatment and dose groups, while glucose, pyruvate, and alanine varied. Acetoacetate was significantly increased in the 10 mg/kg α-HBCD and was nonsignificantly decreased with CM-HBCD. A third ketone body, acetone, was significantly lower in the 30 mg/kg α-HBCD group with significant increases in pyruvate at the same treatment and dose group. Metabolites significant in differentiating treatment and dose groups were also identified, including decreases in amino acids glutamate (excitatory neurotransmitter in learning and memory) and phenylalanine (neurotransmitter precursor) after α-HBCD and γ-HBCD exposure, respectively. CONCLUSIONS: We demonstrated that 4 days following a single neonatal oral exposure to α-, γ-, and CM-HBCD resulted in different serum metabolomic profiles, indicating stereoisomer- and mixture-specific effects and possible mechanisms of action. CITATION: Szabo DT, Pathmasiri W, Sumner S, Birnbaum LS. 2017. Serum metabolomic profiles in neonatal mice following oral brominated flame retardant exposures to hexabromocyclododecane (HBCD) alpha, gamma, and commercial mixture. Environ Health Perspect 125:651-659; http://dx.doi.org/10.1289/EHP242 [ABSTRACT FROM AUTHOR]

Flame retardants are associated to numerous adverse health effects, can accumulate in humans and have been used intensively worldwide. Recently, dust has been identified as a major human exposure route for flame retardants. The aim of this study was to develop a multi-residue method using a two-step SPE purification. It enabled us to effectively limit co-extracted matrix/interferets and therefore a simultaneous analysis of brominated and organophosphate flame retardants for indoor dust was achieved. The optimized method was validated according to standard protocol and achieved good accuracy and reproducibility (percent error ranged from −29% to 28%). Standard Reference Material (SRM) for dust was also analysed, and good agreement was found with reported brominated and organophosphate flame retardants (OPFRs) concentrations. The applicability of the validated method was demonstrated by the analysis of ten indoor dust samples from ten Australian homes. Overall 89% of the analytes were detected in these samples. The average concentrations of ∑OPFRs and ∑PBDEs in those samples were 41 and 3.6 μg/g, respectively. Tris(2-butoxyethyl) phosphate and tris(2-chloroisopropyl) phosphate were the most abundant OPFRs, accounting for 57–92% ∑OPFRs, while decabromodiphenyl ether dominated the Polybrominated diphenyl ethers (PBDE) congeners contributing between 71–94% to the ∑PBDEs. [ABSTRACT FROM AUTHOR]

Many chemicals have been used to increase the safety of consumer products by reducing their flammability and risk for ignition. Recent focus on brominated flame retardants, such as polybrominated diphenyl ethers (PBDEs) has shown them to contribute to neurobehavioral deficits in children, including learning and memory. As the manufacture and use of PBDEs have been reduced, replacement chemicals, such as hexabromocyclododecane (HBCDD) have been substituted. Our current study evaluated the neurotoxicity of HBCDD, concentrating on dopaminergic innervation to the hippocampus. Using an in vivo model, we exposed male mice to HBCDD and then assessed alterations to the dopamine synapse 6 weeks later. These exposures elicited significant reductions in presynaptic dopaminergic proteins, including TH, COMT, MAO-B, DAT, VMAT2, and alpha-synuclein. In contrast, postsynaptic dopamine receptors were not impaired. These findings suggest that the mesohippocampal dopamine circuit is vulnerable to HBCDD and the dopamine terminal may be a selective target for alteration. [ABSTRACT FROM AUTHOR]