Levels and distribution of brominated flame retardants in the soil of Harbin in China

This study reports the presence of brominated flame retardants in the topsoil in and around Harbin, a city in northeastern China. Samples of soil were collected from 17 locations in 2006, and the levels of 9 polybrominated diphenylethers （PBDEs 17, 28, 47, 66, 99, 100, 153, 154, and 183） ranged from 2.45 to 55.9 pg/g dry weight （dw） with a mean of 26.3 pg/g dw. These levels are very low comparing with those for some cities in Europe and USA. BDE 209 and hexabromocyclododecane were the two dominant congeners, with mean concentrations of 520 pg/g dw and 1750 pg/g dw, respectively. The concentrations of the total nine PBDE congeners clearly decreased from urban areas to background, but the compositions of individual congeners differed. Proportions of heavier congeners decreased while those of lighter congeners increased, along urban-rural-background transect, providing evidence for an urban fractionation effect. Correlation analysis indicated similar sources for PBDEs, hexabromocyclododecane, and 1,2-bis（2,4,6-tribromophenoxy）-ethane from urban areas but pentabromoethylbenzene was probably present due to long-range atmospheric transport. Principal component analysis was used to determine the characteristics of the relationships among these brominated flame retardants in the field.

A Simplified Analytical Procedure for Simultaneous Determination of Alkylphenol Ethoxylates and Brominated Flame Retardants in Fish Tissue Samples from Vaal River,South Africa

In this study, the concentration of alkylphenol ethoxylates (APEs) and brominated flame retardants (BFRs) were determined in fish samples, Labeo umbratus and Carp, collected from the Vaal River in South Africa. Ultrasonic-assisted extraction technique was used to extract the organic contaminants from fish samples, and the resulting extract was purified by sulphuric acid lipid removal followed by Strata X-cartridge SPE clean-up. The APEs and BFRs were derivatized using heptafluorobutyric anhydride before analysis with GC-MS. In both types of fish samples, lower oligomers of APEs were more abundant than the higher oligomers, while HBCD, BDE99 and PBB101 were the dominant BFRs. The concentrations of these pollutants ranged from 1.061 ng/g lipids (t-BP) in Labeo umbratus to 11.860 ng/g lipids (HBCD) in Carp.

A review of polybrominated diphenyl ethers and alternative brominated flame retardants in wildlife from China:Levels,trends,and bioaccumulation characteristics

Accelerated industrialization and urbanization,and unregulated disposal of waste of electric and electronic equipment（e-waste） in China have caused environmental pollution of brominated flame retardants（BFRs）.This review summarized the levels,trends,and bioaccumulation characteristics of polybrominated diphenyl ethers（PBDEs） and other potential alternative BFRs including hexabromocyclododecanes（HBCDs）,1,2-bis（2,4,6-dibromophenoxy） ethane（BTBPE） and decabromodiphenylethane（DBDPE） in wildlife from China.PBDE levels in wildlife from China were generally higher than those from other parts in Asia,and were comparable to those from Europe but were lower than those from North America.However,wildlife from the e-waste recycling sites in South China and East China contained much higher PBDEs compared to other reports around the world,suggesting the heavy contamination of PBDEs in these regions.The alternative BFRs were also detected in wildlife,revealing that the animals are exposed to these chemicals,in addition to PBDEs.Temporal trends indicated by levels in marine mammals from South China suggested that PBDE levels increased from the beginning of 1990s to 2000s,but decreased from the middle of 2000s,followed by relatively steady levels.In contrast,HBCDs were found to be continuously increasing from 1997 to 2007,indicating the increasing usage of HBCDs in China in recent years.Compared to PBDE profiles found in other parts,aquatic species and birds from China contained relatively higher contributions of BDE28 and 209,respectively,suggesting the possible different usage pattern of PBDEs.Future works including keeping monitoring at a reasonable scale and frequency to make sure levels near urban centers indicative of population do not increase are needed.Additionally,focus effort on e-waste recycling regions to look for impacts and to determine if regulation/controls are resulting in lower environmental contamination,and incorporation of sentinel species in monitoring efforts are recommended.

Concentrations and distribution of novel brominated flame retardants in the atmosphere and soil of Ny-Alesund and London Island,Svalbard,Arctic

Novel brominated flame retardants(NBFRs)were investigated in Arctic air and soil samples collected from Ny-?lesund and London Island,Svalbard,during Chinese scientific research expeditions to the Arctic during 2014–2015.The concentrations of 9 NBFRs in the Arctic air and soil were 4.9–8.7 pg/m3(average 6.8 pg/m3)and 101–201 pg/g dw(average 150 pg/g dw),respectively.The atmospheric concentration of hexabromobenzene(HBB)was significantly correlated with that of pentabromotoluene(PBT)and pentabromobenzene(PBBz),suggesting similar source and environmental fate in the Arctic air.No significant spatial difference was observed among the different sampling sites,both for air and soil samples,indicating that the effects of the scientific research stations on the occurrence of NBFRs in the Arctic were minor.The fugacities from soil to air of pentabromoethylbenzene(PBEB),2,3-dibromopropyl 2,4,6-tribromophenyl ether(DPTE),and decabromodiphenylethane 1,2-bis(pentabromophenyl)ethane(DBDPE)were lower than the equilibrium value,indicating a nonequilibrium state of these compounds between air and soil,the dominant impact of deposition and the net transport from air to soil.The correlation analysis between the measured and predicted soil-atmosphere coefficients based on the absorption model showed that the impact of the soil organic matter on the distribution of NBFRs in the Arctic region was minor.To the best of our knowledge,this work is one of the limited reports on atmospheric NBFRs in the Arctic and the first study to investigate the occurrence and fate of NBFRs in the Arctic soil.

Detection of novel brominated flame retardants (NBFRs) in the urban soils of Melbourne, Australia

A range of brominated flame retardants(BFRs)have been incorporated into polymeric materials like plastics,electronic equipment,foams and textiles to prevent fires.The most common of these,polybrominated diphenyl ethers(PBDEs),have been subject to legislated bans and voluntary withdrawal by manufacturers in North America,Europe and Australia over the past decade due to long-range atmospheric transport,persistence in the environment,and toxicity.Evidence has shown that replacement novel brominated flame retardants(NBFRs)are released to the environment by the same mechanisms as PBDEs and share similar hazardous properties.The objective of the current research was to characterize soil contamination by NBFRs in the urban soils of Melbourne,Australia.A variety of industrial and nonindustrial land-uses were investigated with the secondary objective of determining likely point sources of pollution.Six NBFRs;pentabromotoluene(PBT),pentabromoethylbenzene(PBEB),hexabromobenzene(HBB),2-ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-TBB),1,2-bis(2,4,6-tribromophenoxy)ethane(BTBPE)and decabromodiphenyl ethane(DBDPE)were measured in 30 soil samples using selective pressurized liquid extraction(S-PLE)and gas chromatography coupled to triple quadrupole mass spectrometry(GC-MS/MS).NBFRs were detected in 24/30 soil samples with S5NBFR concentrations ranging from nd-385 ng/g dw.HBB was the most frequently detected compound(14/30),while the highest concentrations were observed for DBDPE,followed by BTBPE.Electronic waste recycling and polymer manufacturing appear to be key contributors to NBFR soil contamination in the city of Melbourne.A significant positive correlation between S8PBDEs and S5NBFR soil concentrations was observed at waste disposal sites to suggest that both BFR classes are present in Melbourne's waste streams,while no association was determined among manufacturing sites.This research provides the first account of NBFRs in Australian soils and indicates that these emerging contaminants possess a similar potential to contaminate Melbourne soils as PBDEs.

Temporal trends in concentrations of legacy and novel brominated flame retardants in house dust from Birmingham in the United Kingdom

Concentrations of polybrominated diphenyl ethers(PBDEs),hexabromocyclododecane(HBCDD),tetrabromobisphenol-A(TBBPA)and two potential replacements decabromodiphenylethane(DBDPE)and 1,2-bis(2,4,6-tribromophenoxy)ethane(BTBPE)were measured in dust samples collected from 14 homes across Birmingham(UK).Concentrations were compared with those from the same city in previous studies to ascertain any temporal changes and to assess the effects of legislative restrictions.The average PHBCDDs concentration(46,000 ng/g;median=280 ng/g)included the highest dust concentration recorded globally(570,000 ng/g).This is despite the listing of HBCDD under the Stockholm Convention in 2013,demonstrating that decreases in indoor contamination will likely be slow as existing sources are gradually discarded.In contrast,concentrations of BDE-47(mean=5.7 ng/g;median=0.93 ng/g)and BDE-99(mean=11 ng/g;median=2.9 ng/g)were significantly lower than in all previous(p<0.01)studies in the same city since 2006,suggesting restrictions on the Penta-BDE formulation have been effective.The average BDE-209 concentration(4800 ng/g;median=1600 ng/g)is lower than the peak average concentration,which was observed in 2007(280,000 ng/g),however this is not a significant decline,probably due to the later imposition of Deca-BDE restrictions compared to those on Penta-BDE.Decreases in PBDE concentrations have coincided with a significant(p<0.01)increase in DBDPE concentrations(average=1500 ng/g;median=660 ng/g)since 2014,suggesting its use as a replacement flame retardant for Deca-BDE.While no significant change was detected for BTBPE(average 11 ng/g;median=0.84 ng/g in this study);concentrations of TBBPA(average=34 ng/g;median=35 ng/g)were significantly lower(p<0.05)than in 2007(average 62 ng/g).The decreases observed in PBDE concentrations,demonstrates that legislation has been effective in reducing the commercial use of PBDEs,however this has coincided with increases of alternative flame retardants such as DBDPE.

A hybrid monolithic column based on flower-shaped zeolitic imidazolate framework for efficient capillary microextraction of brominated flame retardants

A novel flower-shaped zeolitic imidazolate framework(ZIF) doped organic-inorganic hybrid monolithic column(ZIF-HMC) was prepared by a simple sol-gel "one-step" method and utilized for efficient capillary microextraction(CME) of four brominated flame retardants.The prepared monolithic was characterized by Fourier transform infrared,scanning electron microscopy,X-ray photoelectron spectroscopy,energy disperse spectroscopy,and N_(2) adsorption-desorption.The parameters of CME were optimized by orthogonal array design.Under the optimal conditions,the ZIF-HMC showed excellent extraction efficiency,the limit of detection(LODs) and the limit of quantification(LOQs) were in the range of0.52$3.1 mg/L and 1.7$10 mg/L,respectively,and the proposed method demonstrated good recovery(88.8%–116.6%) with the RSD less than 13.6% and a reusability of at least 30 times.The ZIF-HMC possessed great potential for separating organic pollutants and the strategy used here could be extended to prepare other derivatized HMC functionalized monoliths.

Particle size distribution of brominated flame retardants in house dust from Japan

The present study was conducted to examine the concentrations,profiles,and mass distributions of polybrominated diphenyl ethers(PBDEs),hexabromocyclododecanes(HBCDs),and polybrominated dibenzo-p-dioxins/furans(PBDD/Fs)based on the particle sizes of house dust samples from five homes in Japan.After removal of impurities from house dust from vacuum cleaner bags,selected indoor dust samples were size fractionated(>2 mm,1-2 mm,0.5-1 mm,250-500 mm,106-250 mm,53-106 mm,and<53 mm).Fluffy dust was collected separately for particle size analysis.PBDEs,HBCDs,and PBDFs were detected in all the samples analyzed.In general,PBDE levels of particulate and fluffy dust were comparable and the highest concentrations were found in 106-250 mm or 53-106 mm fractions.HBCD concentrations in fluffy dust were higher than those in particulate dust,and their levels were the highest in 106-250 mm and 250e500 mm factions,respectively.The highest concentrations of all three compound groups were not found in particles<53 mm in size,suggesting that the distribution of brominated flame retardants does not depend solely on the surface area-to-volume ratios of dust particles.The concentrations of PBDEs and PBDD/Fs depended principally on the concentrations in particles<53 mm in size because the predominant mass of particulate dust were found in this fraction.The mesh size used for sample preparation will thus have little effect on the concentrations as long as particles<53 mm are included.In contrast,HBCD concentrations increased by as much as 80%when particles>250 mm in size and fluffy dust were included.The conclusion is that particulate dust<250 mm in size without fluffy dust should be used to analyze dust for brominated flame retardants.

The presence and partitioning behavior of flame retardants in waste,leachate,and air particles from Norwegian waste-handling facilities

Flame retardants in commercial products eventually make their way into the waste stream.Herein the presence of flame retardants in Norwegian landfills, incineration facilities and recycling sorting/defragmenting facilities is investigated. These facilities handled waste electrical and electronic equipment（WEEE）, vehicles, digestate, glass, combustibles, bottom ash and fly ash. The flame retardants considered included polybrominated diphenyl ethers（∑BDE-10） as well as dechlorane plus, polybrominated biphenyls, hexabromobenzene,pentabromotoluene and pentabromoethylbenzene（collectively referred to as ∑FR-7）. Plastic,WEEE and vehicles contained the largest amount of flame retardants（∑BDE-10： 45,000–210,000 μg/kg; ∑FR-7： 300–13,000 μg/kg）. It was hypothesized leachate and air concentrations from facilities that sort/defragment WEEE and vehicles would be the highest. This was supported for total air phase concentrations（∑BDE-10： 9000–195,000 pg/m^3 WEEE/vehicle facilities, 80–900 pg/m^3 in incineration/sorting and landfill sites）, but not for water leachate concentrations（e.g., ∑BDE-10： 15–3500 ng/L in WEEE/Vehicle facilities and 1–250 ng/L in landfill sites）. Landfill leachate exhibited similar concentrations as WEEE/vehicle sorting and defragmenting facility leachate. To better account for concentrations in leachates at the different facilities, waste-water partitioning coefficients, Kwastewere measured（for the first time to our knowledge for flame retardants）. WEEE and plastic waste had elevated Kwastecompared to other wastes, likely because flame retardants are directly added to these materials. The results of this study have implications for the development of strategies to reduce exposure and environmental emissions of flame retardants in waste and recycled products through improved waste management practices.

Current-use halogenated and organophosphorous flame retardants:A review of their presence in Arctic ecosystems

Since the ban of polybrominated diphenyl ethers(PBDEs)and hexabromocyclododecane(HBCDD),other flame retardants may be increasingly used.Thirty-one current-use halogenated(HFRs)and 24 organophosphorous flame retardants(PFRs)have been sought in Arctic ecosystems so far.Air measurements provide evidence of long-range atmospheric transport for the majority of these compounds,with much higher concentrations for PFRs than for HFRs.Some HFRs,i.e.bis(2-ethylhexyl)-tetrabromophthalate(BEH-TEBP),2-ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-TBB)and hexabromobenzene(HBBz),had air concentrations comparable to those of PBDEs in some studies.Complementary data for seawater and ice indicate dry deposition of HFRs,while net volatilization from seawater was observed for some PFRs.Studies in the marine environment indicate a wide presence of HFRs in marine biota,but generally at low levels,i.e.typically lower than those of PBDEs.Exceptions exist,namely 2,4,6-tribromophenyl 2,3-dibromopropyl ether(TBP-DBPE)and decabromodiphenyl ethane(DBDPE),which were found in concentrations comparable to PBDEs in some species.The same was the case for 2,4,6-tribromophenyl allyl ether(TBP-AE)in a study from the terrestrial environment.PFRs generally had low concentrations in biota,probably due to metabolic transformation of PFR triesters,as suggested by in vitro studies.Elevated PFR concentrations occurred in some individuals,generally indicating a larger variability of PFRs in biota than found for HFRs.The commercially important tetrabromobisphenol A(TBBPA)was only detected sporadically,and only in abiotic matrices.

Novel biomonitoring method for determining five classes of legacy and alternative flame retardants in human serum samples

Flame retardants(FRs)are ubiquitous in environment and biota and may pose harm to human health.In recent years,concern regarding legacy and alternative FRs has been intensified due to their widespread production and increasing contamination in environmental and human matrices.In this study,we developed and validated a novel analytical method for simultaneous determination of legacy and alternative FRs,including polychlorinated naphthalenes(PCNs),short-and middle-chain chlorinated paraffins(SCCPs and MCCPs),novel brominated flame retardants(NBFRs),and organophosphate esters(OPEs)in human serum.Serum samples were prepared by liquid-liquid extraction using ethyl acetate,and purified with Oasis®HLB cartridge and Florisil–silica gel columns.Instrumental analyses were carried out using gas chromatography-triple quadrupole mass spectrometry,highresolution gas chromatography coupled with high-resolution mass spectrometry,and gas chromatography coupled with quadrupole time-of-flight mass spectrometry,respectively.The proposed method was validated for linearity,sensitivity,precision,accuracy,and matrix effects.Method detection limits for NBFRs,OPEs,PCNs,SCCPs,and MCCPs were 4.6×10^(–4)–8.6×10^(–2),4.3×10^(–3)–1.3,1.1×10^(–5)–1.0×10^(–4),1.5,and 9.0×10–1 ng/mL,respectively.Matrix spike recoveries ranged from 73%–122%,71%–124%,75%–129%,92%–126%,and 94%–126%for NBFRs,OPEs,PCNs,SCCPs,and MCCPs,respectively.The analytical method was applied for detection of real human serum.CPs were the dominant FRs in serum,indicating CPs were widely presented in human serum and should be pay more attention for their health risk.

Detection of tris-(2, 3-dibromopropyl) isocyanurate as a neuronal toxicant in environmental samples using neuronal toxicity-directed analysis

Neuronal toxic pollutants in environment possess hazards to human health. It is essential to determine the causative neuronal toxicants in environmental samples. In the present study, viability of primary cultured cerebellar granule neurons (CGNs), combined with sample extraction, chemical fractionation and identification, was applied for screening acid-resistant neuronal toxic substances in environmental samples. River sediments and agricultural soils along the river near a brominated flame retardant (BFR) manufacturing plant in South China were collected to screen the key neuronal toxicants. The results indicated that the manufacturing plant was a source of neuronal toxicity risks. In the sediment and soil near the plant, one of the causative toxicants was identified as tris-(2,3-dibromopropyl) isocyanurate (TBC) using HPLC-MS/MS. In addition, an unknown chemical possibly causing significant neuronal toxicity was isolated from all the soil samples in the region.

Parental and transgenerational impairments of thyroid endocrine system in zebrafish by 2,4,6-tribromophenol

Many environmental contaminants could be transmitted fromparents and generate impairments to their progeny.The 2,4,6-tribromophenol(TBP),a novel brominated flame retardant which has been frequently detected in various organisms,was supposed to be bioaccumulated and intergenerational transmitted in human beings.Previous studies revealed that TBP could disrupt thyroid endocrine system in zebrafish larvae.However,there is no available data regarding the parental and transgenerational toxicity of this contaminant.Thus,in this study adult zebrafish were exposed to environmental contaminated levels of TBP for 60 days to investigate the parental and transgenerational impairments on thyroid endocrine system.Chemical analysis verified the bioaccumulation of TBP in tested organs of parents(concentration:liver>gonads>brain)and its transmission into eggs.For adults,increased thyroid hormones,disturbed transcriptions of related genes and histopathological changes in thyroid follicles indicate obvious thyroid endocrine disruptions.Transgenerational effects are indicated by the increased thyroid hormones both in eggs(maternal source)and in developed larvae(newly synthesized),aswell as disrupted transcriptional profiles of key genes in HPT axis.The overall results suggest that the accumulated TBP could be transmitted from parent to offspring and generate thyroid endocrine disruptions in both generations.

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

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 yielding2,4,6-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.

Occurrence and distribution of tetrabromobisphenol A and its derivative in river sediments from Vaal River Catchment,South Africa

Brominated flame retardants(BFRs)compounds have been widely added in a number of products to reduce their flammability.In the present study,the concentrations and distribution of tetrabromobisphenol A(TBBPA)and its derivatives,i.e.tribromophenol dibromopropyl ether(TBPDBPE),tetrabromobisphenol A bis-dibromopropyl ether(TBBPA BDBPE),tetrabromobisphenol A bis-allyl ether(TBBPA BAE)were investigated in sediment samples collected from the Vaal River catchment,South Africa.The results showed that all these pollutants were detected in sediments with TBBPA BAE being the most abundant contaminant.The TBBPA BAE concentrations ranged from 3.5 to 44.4 ng/g(mean 16 ng/g)while the concentration ranged from not detected(nd)to 2.4 ng/g(mean 0.6 ng/g),nd-21.0 ng/g(mean 6 ng/g)and nd-2.0 ng/g(mean 0.2 ng/g)for TBPDBPE,TBBPA and TBBPA BDBPE;respectively.Higher concentrations of these pollutants were found in sampling sites receiving effluents of wastewater treatment works(WWTWs)treating some industrial wastewater suggesting effluents might play an important role in the contamination of BFRs in the environment.Negative correlation between TBBPA and TBBPA BAE was observed implying different sources or environmental fates between these pollutants.Overall,the results showed a need for further studies to be undertaken in investigating the presence,fate and sources of alternative halogenated flame retardants in the environment.

Laboratory studies on leaching of HBCDD from building insulation foams

A series of laboratory experiments were conducted to study emissions of hexabromocyclododecane(HBCDD)into aqueous leaching fluid under simulated landfill conditions.Expanded(EPS)and extruded(XPS)polystyrene building insulation foam samples containing HBCDD were contacted with deionised Milli-Q water containing 0,100 and 1000 mg L
1 dissolved humic matter(DHM)as leaching fluid.Concentrations of HBCDD were determined in the resulting fluid and single and serial batch experiments conducted.The impacts on HBCDD concentrations in the leaching fluid temperature and pH were examined.Data from these experiments show that HBCDD concentrations in leaching fluid following contact with EPS and XPS almost all exceeded the aqueous solubilities for each diastereomer and the technical HBCDD formula.This indicates that agitation and abrasion of EPS and XPS were significant mechanisms of HBCDD emission to leaching fluid.Specifically,under such conditions,HBCDD is likely associated with fine abraded particles of the foam and concentrations in the leaching fluid are therefore not limited by the aqueous solubility of HBCDD.Consistent with this,the length of contact time had a significant positive effect on concentrations of all diastereomers in the leaching fluid for XPS and for the least soluble diastereomer,g-HBCDD for EPS.Generally,the presence of DHM in the leaching fluid and elevated leaching fluid temperatures had significant positive effects on HBCDD concentrations in leaching fluid for both EPS and XPS.Overall,while leaching fluids of pH 8.5 significantly enhanced concentrations of a-HBCDD released from EPS,pH exerts a minor effect on concentrations of HBCDD in leaching fluid.

Leaching of decabromodiphenyl ether and hexabromocyclododecane from fabrics under simulated landfill conditions

A series of laboratory experiments were conducted to examine the leaching of decabromodiphenyl ether(BDE-209)and hexabromocyclododecane(HBCDD)from a mix of three fabrics.Consistent with previous reports that such leaching is governed by second order kinetics,concentrations in leachate were markedly higher in the first 24 h of leaching,and diminished by an order of magnitude after 1 week.The influence of the waste:leachate ratio was examined for the first time,with leaching of both BDE-209 and HBCDD significantly greater(p<0.05)at a waste:leachate ratio of 0.005 g/mL than at 0.05 g/mL.Using dissolved humic matter(DHM)solutions as proxy for simulating organic landfill leachates we found that leaching of both BDE-209 and HBCDD was also significantly greater at a DHM concentration of 1,000 mg/L in leachate compared to that observed at DHM values of 100 and 0 mg/L.Agitation of waste:leachate mixtures significantly enhanced leaching.While leaching of HBCDD decreased significantly as leachate pH increased from 5.8,through 6.5,to 8.5;no significant impact of pH on leaching of BDE-209 was detected.Concentrations in leachate of both BDE-209 and HBCDD decreased significantly on increasing leachate temperature from 20℃to 60℃and 80℃.This is considered most likely due to volatilisation of these contaminants into the headspace of the leaching vessel at higher temperatures.

A meta-analysis of recent data on UK environmental levels of POP-BFRs in an international context: Temporal trends and an environmental budget

This study collates and synthesises UK data on environmental levels of POP-BFRs published between 1999 and March 2015.Target POP-BFRs are:the polybrominated diphenyl ether(PBDE)formulations Penta-BDE,Octa-BDE,and Deca-BDE(the latter as a candidate Stockholm Convention POP),as well as hexabromocyclododecane(HBCDD).Environmental compartments covered include:sediments(freshwater and marine),atmospheric deposition(both measured directly and inferred from sediment core data),soil,herbage,outdoor air,indoor air,indoor dust,freshwater(rivers and lakes),human tissues(blood serum and milk),wildlife,and the human diet.Temporal trends in contamination were examined for evidence of environmental responses to regulatory and voluntary actions banning/restricting the manufacture and use of POP-BFRs.Good evidence exists that-with some exceptions-concentrations of Penta-BDE congeners like BDEs-47 and 99 have responded well to the use restrictions introduced in the mid-2000s.However,it appears that human body burdens of these contaminants do not appear to have responded in a similar way,as levels in UK human milk in 2010e2012,are not discernibly different to those reported in 2002e03.The evidence for HBCDD and BDEs-183 and 209 is less abundant,but signs exist that absolute concentrations of BDE-183 are falling in the UK environment.With respect to BDE-209,evidence from analysis of lake sediment core and UK diet samples,suggests that levels have yet to respond discernibly to the more recent curbs on manufacture and use of Deca-BDE.The limited evidence for HBCDD is strongly consistent with a declining trend in environmental contamination with this chemical.Broadly,examination of the UK database in an international context,suggests UK levels are generally within the range of those found in other industrialised countries.Interestingly,while UK concentrations of BDE-209 in abiotic matrices such as indoor dust,are at the high end of those reported globally;concentrations in UK human milk are amongst the lowest reported to date.This suggests that the bioavailability of BDE-209 from indoor dust is likely very low.An environmental budget was estimated for the UK burden of POP-BFRs.As with previous comparable exercises for polychlorinated biphenyls(PCBs)and chlorinated dioxins,the majority(>90%)of the UK burden of POP-BFRs resides in soil.Moreover,the POPBFR burden identifiable as present in the UK environment is much lower than data on production and use of POP-BFRs in Europe.This may be explained by POP-BFRs:(a)undergoing environmental transport away from the UK;(b)undergoing environmental degradation;(c)remaining in use;and(d)entering the waste stream.While the UK database appears relatively strong for some environmental compartments and POPBFRs e e.g.BDEs-47 and-99 are well-characterised in the human diet,indoor air/dust,and human milk e substantial gaps exist for BDE-209 and HBCDD in air(indoor and outdoor),herbage,and soil.