Concentrations Of Hexabromobenzene Research Articles

Dietary intake of legacy and emerging halogenated flame retardants using food market basket estimations in Nanjing, eastern China

Food products are inevitably contaminated by flame retardants throughout their lifecycle (i.e., during production, use, and disposal). In order to evaluate the dietary intake of legacy and emerging halogenated flame retardants (HFRs) in typical market food in China, we investigate the distribution and profile of 27 legacy polybrominated diphenyl ethers (PBDEs) and 16 emerging HFRs (EHFRs) in 9 food categories (meat, poultry, aquatic food, eggs, dairy products, cereals, vegetables, nuts and fruits, and sugar). A total of 105 food samples collected from three markets in Nanjing, eastern China were included for evaluation. The highest concentrations of PBDEs and EHFRs were found in aquatic foods (means of 0.834 ng/g wet weight (ww) and 0.348 ng/g ww, respectively), and the lowest concentrations were found in sugar (means of 0.020 ng/g ww for PBDEs and 0.014 ng/g ww for EHFRs). 2,2′,4-tribromodiphenyl ether (BDE-17), a legacy HFR, and hexabromobenzene (HBBz), an EHFR, were the predominant pollutants in the investigated food samples. Concentrations of HBBz and 2,3-dibromopropyl tribromophenyl ether (DPTE) were comparable to those of some PBDEs in certain food samples. The concentrations of the total EHFRs and total PBDEs found in animal-based food samples were significantly greater than those in plant-based food samples. Comparison of the estimated total dietary intake of HFRs and their corresponding non-cancer reference dose (United States Environmental Protection Agency) suggests a low overall health risk. To the best of our knowledge, the present study is the first to simultaneously determine 27 PBDEs and 16 EHFRs in representative foods from Chinese markets. BDE-17, HBBz, and DPTE were the predominant congeners among the 43 investigated HFRs and meat and aquatic foods were the primary sources of PBDEs and EHFRs to the total local dietary intake.

Associations between organohalogen exposure and thyroid- and steroid-related gene responses in St. Lawrence Estuary belugas and minke whales

Elevated concentrations of persistent organic pollutants (POPs) and emerging halogenated flame retardants (HFRs) have been reported in tissues of the endangered St. Lawrence Estuary (Canada) beluga population as well as in minke whales visiting that same feeding area. This study examined the linkages between blubber concentrations of POPs and emerging HFRs, and transcription in skin of genes involved in the regulation of thyroid and steroid axes in belugas and minke whales from the St. Lawrence Estuary. In belugas, concentrations of PCBs, OCs and hexabromobenzene (HBB) were positively correlated with the transcription of thyroid- and/or steroid-related genes, while Dec-604 CB concentrations were negatively associated with the transcription of glucocorticoid and thyroid genes. In minke whales, PBDE concentrations changed positively with Esrβ transcript levels and HBB concentrations negatively with Nr3c1 transcripts. Present results suggest that several biological functions including reproduction and energetic metabolism may represent potential targets for organohalogens in these whales.

Occurrence, composition, source, and regional distribution of halogenated flame retardants and polybrominated dibenzo-p-dioxin/dibenzofuran in the soils of Guiyu, China

Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2′,4,4′,5,5’-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13–1014 ng g−1. The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048–3.3 ng g−1, while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8–153 ng g−1 and 0.43–15 ng g−1, respectively. DP was another primary FR, with concentrations of 0.57–146 ng g−1. Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5–17 pg TEQ g−1. 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants.

Temporal trends of PBDEs and emerging flame retardants in belugas from the St. Lawrence Estuary (Canada) and comparisons with minke whales and Canadian Arctic belugas

An exponential level increase of the ubiquitous halogenated flame retardant (HFR) class polybrominated diphenyl ether (PBDE) has been documented during the 1990s in endangered belugas (Delphinapterus leucas) from the St. Lawrence Estuary (SLE), Eastern Canada. The recent worldwide bans and regulations of PBDE mixtures led to their replacement by alternative HFRs (so-called emerging HFRs) that are increasingly being reported in various environmental compartments. There are, however, limited knowledge on the spatial and temporal trends of PBDEs and emerging HFRs in cetaceans, especially after restrictions on PBDE usage. The first objective of this study was to investigate the occurrence of HFRs (35 PBDE congeners and 13 emerging compounds) in the blubber of belugas and minke whales (Balænoptera acutorostrata) found dead in the Estuary or Gulf of St. Lawrence as well as belugas from Nunavik (Canadian Arctic) collected as part of the Inuit subsistence hunt. A second objective was to investigate the trends of HFR concentrations in SLE beluga males between 1997 and 2013. PBDEs were the most abundant HFRs in all three whale populations, while hexabromobenzene (HBB), Chlordene Plus (CPlus), Dechlorane Plus (DP), and Dechlorane 604 Component B (Dec-604 CB) were quantified in the majority of blubber samples. Overall, concentrations of emerging HFRs were notably greater in SLE belugas compared to the two other whale populations, with the exception of DP and Dec-604 CB that were found in greater concentrations in Canadian Arctic belugas. No significant trend in blubber PBDE concentrations was found in SLE belugas during this 17-year period. This suggests that global PBDE regulations are too recent to observe changes in PBDE concentrations in belugas from this highly HFR-exposed environment. In contrast, concentrations of HBB and CPlus in SLE belugas decreased slightly from 1997 to 2013, while DP increased up until 2000 and decreased slightly thereafter. The occurrence and temporal variations of PBDEs and their replacement products in these cetaceans warrant continuous monitoring.

Trends in the levels of halogenated flame retardants in the Great Lakes atmosphere over the period 2005–2013

Air (vapor and particle phase) samples were collected every 12days at five sites near the North American Great Lakes from 1 January 2005 to 31 December 2013 as a part of the Integrated Atmospheric Deposition Network (IADN). The concentrations of 35 polybrominated diphenyl ethers (PBDEs) and eight other halogenated flame retardants were measured in each of the ~1,300 samples. The levels of almost all of these flame retardants, except for pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), and Dechlorane Plus (DP), were significantly higher in Chicago, Cleveland, and Sturgeon Point. The concentrations of PBEB and HBB were relatively high at Eagle Harbor and Sturgeon Point, respectively, and the concentrations of DP were relatively high at Cleveland and Sturgeon Point, the two sites closest to this compound's production site. The data were analyzed using a multiple linear regression model to determine significant temporal trends in these atmospheric concentrations. The concentrations of PBDEs were decreasing at the urban sites, Chicago and Cleveland, but were generally unchanging at the remote sites, Sleeping Bear Dunes and Eagle Harbor. The concentrations of PBEB were decreasing at almost all sites except for Eagle Harbor, where the highest PBEB levels were observed. HBB concentrations were decreasing at all sites except for Sturgeon Point, where HBB levels were the highest. DP concentrations were increasing with doubling times of 3–9years at all sites except those closest to its source (Cleveland and Sturgeon Point). The levels of 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE) were unchanging at the urban sites, Chicago and Cleveland, but decreasing at the suburban and remote sites, Sturgeon Point and Eagle Harbor. The atmospheric concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP) were increasing at almost every site with doubling times of 3–6years.

Concentrations and distributions of polybrominated diphenyl ethers and novel brominated flame retardants in tree bark and human hair from Yunnan Province, China

The concentrations and distributions of polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs) in tree bark and hair samples from the same area in Yunnan Province, China, were determined. The total PBDE and NBFR concentrations in the tree bark samples were 3.8 ng/g lipid weight to 91 ng/g lipid weight and 0.23 ng/g lipid weight to 5.0 ng/g lipid weight, respectively. The total PBDE and NBFR concentrations in the hair samples were 2.1 ng/g dry weight to 14 ng/g dry weight and 0.083 ng/g dry weight to 0.29 ng/g dry weight, respectively. Decabromodiphenyl ether had similar distributions in the tree bark and hair samples, but other PBDE congeners and NBFRs had different distributions in the tree bark and hair samples. External exposure was found to be mainly responsible for the total PBDE and pentabromotoluene concentrations in hair, but both external and internal exposure were responsible for the pentabromophenyl and hexabromobenzene concentrations in hair.

Polybrominated diphenyl ethers and new polybrominated flame retardants in tree bark from western areas of China.

Tree bark samples were collected from 15 sites across western China in 2013, and the polybrominated diphenyl ether (PBDE) and new polybrominated flame retardant (NBFR) concentrations in the samples were determined. The mean total PBDE concentration was 51.8 ng/g lipid weight, which was 85.2% to 99.4% lower than in Chinese eastern coastal areas and the E-waste recycling areas. The dominant PBDE congener was BDE209, and its mean concentration was 49 ng/g lipid weight. The mean 2,3,5,6-tetrabromo-p-xylene, pentabromobenzene, pentabromotoluene, and hexabromobenzene concentrations were 0.61 ng/g, 0.97 ng/g, 0.68 ng/g, and 0.68 ng/g lw, respectively. The PBDE and NBFR concentrations in the air at the sampling sites were estimated from the concentrations in the tree bark samples. The estimated mean total PBDE and total NBFR concentrations in air were 58.5 pg/m(3) and 2.76 pg/m(3) , respectively. The sources of NBFR emissions were found to be different from the sources of PBDE emissions, as no relationship was found between the NBFR and PBDE concentrations, and it appeared that sources of measured hexabromobenzene, pentabromobenzene, and pentabromotoluene in tree bark in western China include industrial activity related to the aluminum industry. Environ Toxicol Chem 2016;35:1364-1370. © 2015 SETAC.

Has the Phase-Out of PBDEs Affected Their Atmospheric Levels? Trends of PBDEs and Their Replacements in the Great Lakes Atmosphere

Air and precipitation samples were collected every 12 days at five sites near the North American Great Lakes from 2005 to 2011 (inclusive) by the Integrated Atmospheric Deposition Network (IADN). The concentrations of polybrominated diphenyl ethers (PBDEs) and selected alternative brominated flame retardants [pentabromoethyl benzene (PBEB), hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE or BTBPE), decabromodiphenylethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), and bis(2-ethylhexyl)-tetrabromo-phthalate (TBPH)] were measured in these samples. The concentrations of almost all of these flame retardants were related to the number of people within a 25 km radius of the sampling site, except for HBB, the concentrations of which were relatively high at Sturgeon Point, and PBEB, the concentrations of which were relatively high at Eagle Harbor. The temporal trends of all of these concentrations were variable. For example, BDE-47 vapor phase concentrations were increasing with doubling times of 5-10 years at Sturgeon Point, Sleeping Bear Dunes, and Eagle Harbor, but these concentrations were slowly decreasing in all phases at Chicago. The most consistent trend was for TBE, which showed concentrations that were unchanging or decreasing in all phases at all sites. TBPH concentrations in particles and HBB concentrations in precipitation were rapidly increasing at most sites with doubling times of ~2 years. The concentrations of DBDPE and BDE-209 were strongly and positively correlated, and the concentrations of TBB and TBPH were also strongly and positively correlated. The concentrations of TBB plus TBPH (representing Firemaster 550) and BDE-47, 85, 99, 100, 153, plus 154 (representing the withdrawn penta-BDE commercial mixture) were also strongly and positively correlated. These positive relationships indicate that the replacement of the deca-BDE commercial product by DBDPE and the penta-BDE product by Firemaster 550 have not yet become evident in the Great Lakes' atmospheric environment.

Discontinued and Alternative Brominated Flame Retardants in the Atmosphere and Precipitation from the Great Lakes Basin

Air (vapor and particle) and precipitation samples were collected at five sites (two urban, one rural, and two remote) around the Great Lakes during 2005-2009 as a part of the Integrated Atmospheric Deposition Network (IADN). The concentrations of polybrominated diphenyl ethers (PBDEs), decabromodiphenylethane (DBDPE), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were measured in these samples. The highest concentrations of these compounds were generally observed at the two urban sites-Chicago and Cleveland-with a few exceptions: The remote site at Eagle Harbor had particularly high levels of PBEB in all three phases, and the rural Sturgeon Point site had the highest HBB concentrations in the vapor phase. The sources of HBB and PBEB to these sites are unknown. A multiple linear regression model was applied to the concentrations of these compounds in the vapor phase, particle phase, precipitation, and the three phases combined. This regression resulted in overall (three phases combined) halving times for total PBDE concentrations of 6.3 ± 1.1 years. The overall halving times for HBB and BTBPE were 9.5 ± 4.6 years and 9.8 ± 2.8 years, respectively. For PBEB and DBDPE, the regression was not statistically significant for the combined phases, indicating that the atmospheric concentrations of these compounds have not changed between 2005 and 2009.