Geographical distribution of non-PBDE-brominated flame retardants in mussels from Asian coastal waters

Hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and decabromodiphenyl ethane (DBDPE) used as alternatives for polybrominated diphenyl ethers (PBDEs) are also persistent in the environment as PBDEs. Limited information on these non-PBDE brominated flame retardants (BFRs) is available; in particular, there are only few publications on environmental pollution by these contaminants in the coastal waters of Asia. In this regard, we investigated the contamination status of HBCDs, BTBPE, and DBDPE in the coastal waters of Asia using mussels as a bioindicator. Concentrations of HBCDs, BTBPE, and DBDPE were determined in green (Perna viridis) and blue mussels (Mytilus edulis) collected from the coastal areas in Cambodia, China (mainland), SAR China (Hong Kong), India, Indonesia, Japan, Malaysia, the Philippines, and Vietnam on 2003-2008. BTBPE and DBDPE were analyzed using GC-MS, whereas HBCDs were determined by LC-MS/MS. HBCDs, BTBPE, and DBDPE were found in mussels at levels ranging from <0.01 to 1,400, <0.1 to 13, and <0.3 to 22?ng/g lipid wt, respectively. Among the three HBCD diastereoisomers, α-HBCD was the dominant isomer followed by γ- and β-HBCDs. Concentrations of HBCDs and DBDPE in mussels from Japan and Korea were higher compared to those from the other Asian countries, indicating extensive usage of these non-PBDE BFRs in Japan and Korea. Higher levels of HBCDs and DBDPE than PBDEs were detected in some mussel samples from Japan. The results suggest that environmental pollution by non-PBDE BFRs, especially HBCDs in Japan, is ubiquitous. This study provides baseline information on the contamination status of these non-PBDE BFRs in the coastal waters of Asia.     

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

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

Levels and sources of brominated flame retardants in human hair from urban, e-waste, and rural areas in South China

Human hair and indoor dust from urban, e-waste, and rural areas in south China were collected and analyzed for brominated flame retardants (BFRs). BFRs concentrations in hair from occupational e-waste recycling workers were higher than those from non-occupational exposed residents in other sampling areas. Polybrominated diphenyl ethers (PBDEs) and decabromodiphenyl ethane (DBDPE) are two major BFRs in hair samples. The PBDE congener profiles in hair from the e-waste area are different from those from urban and rural areas with relatively higher contribution of lower brominated congeners. DBDPE, instead of BDE209, has become the major BFR in non-e-waste recycling areas. Significant correlations were found between hair level and dust level for DBDPE and BTBPE but not for PBDEs. The different PBDE congener profiles between dust and hair may suggest that exogenous exposure to the PBDE adsorbed on dust is not a major source of hair PBDEs.     

Structure characterization and thermal stabilities of the isomers of the brominated flame retardant 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane

1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) is used primarily as an additive flame retardant. 1H NMR spectroscopy and an X-ray structure determination have revealed that a technical mixture consists largely of two (of the four possible) diastereomers, rac-(1R,2R)-1,2-dibromo-(4S)-4-((1S)-1,2-dibromoethyl)cyclohexane (alpha-TBECH) and rac-(1R,2R)-1,2-dibromo-(4S)-4-((1R)-1,2-dibromoethyl)cyclohexane (beta-TBECH), in a mole ratio of approximately 1:1. The two other possible isomers, gamma- and delta-TBECH, were not detected in a technical mixture. The TBECH isomers are thermally sensitive and can easily interconvert at temperatures of 125 degrees C. A thermal equilibrium mixture of alpha-, beta-, gamma- and delta-TBECH consists of approximately 33%, 33%, 17% and 17% of these isomers, respectively. Separation of all four TBECH diastereomers, with minimal thermal interconversion of the isomers, was achieved by careful selection of GC-capillary column length and injector temperature. Although technical TBECH does not contain the gamma- and delta-isomers, they may still be relevant environmental contaminants since manufacturing processes utilize thermal processes which may induce their formation.     

Characterization of polychlorinated biphenyls and brominated flame retardants in surface soils from Surabaya, Indonesia

In this study, soil contamination by PCBs, PBDEs, HBCDs and two novel BFRs such as 1,2-bis-(2,4,6-tribromopenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in various locations such as industrial, urban, rural, dumping site and agricultural areas of Surabaya, Indonesia has been characterized in order to evaluate their contamination status, profiles, potential sources, fate and behavior. Range and median concentrations of PCBs, PBDEs, HBCDs, BTBPE and DBDPE were ND - 9.6 (1.2), 0.069 - 24 (7.4), ND - 1.8 (0.48), ND - 1.7 (0.14) and ND - 7.6 (2.2) ng g⁻¹ dw, respectively. Industrial, urban and dumping areas were inventoried as the main sources of these pollutants. Decreasing gradient levels were observed for these contaminants from industrial district, urban, dumping site, rural and agricultural areas, in that order. Furthermore, organic carbon contents and proximity to the point sources were found as the major controlling factors. Contaminant profiles were characterized by the predominance of hexa-, hepta- and penta-homologues for PCBs; deca-, nona- and octa- for PBDEs and α-isomer for HBCDs. Product mixtures such as Ar1260/KC600 and Ar1254/KC500 for PCBs, deca- and octa-BDEs for PBDEs were the possible common formulations used in study area. To our knowledge, this is a first comprehensive study on characterization of soil contamination by PCBs, PBDEs and HBCDs together with two novel BFRs in a highly industrialized city located in tropical region. This study provides baseline information for establishing national monitoring programs in Indonesia.     

Polybrominated diphenyl ethers in background surface soils from the Yangtze River Delta (YRD), China: occurrence,sources, and inventory

Purposes  

Very few data for polybrominated diphenyl ethers (PBDEs) were available in the Yangtze River Delta (YRD), one of the most developed and urbanized region in China. In this study, Chongming Island, located at the estuary of the Yangtze River, was selected as background area to investigate the occurrence, sources, and inventory of PBDEs.     

Brominated flame retardants in the hair and serum samples from an e-waste recycling area in southeastern China: the possibility of using hair for biomonitoring

Hair samples and paired serum samples were collected from e-waste and urban areas in Wenling of Zhejiang Province, China. The PBDE and DBDPE concentrations in hair and serum samples from e-waste workers were significantly higher than those of non-occupational residents and urban residents. BDE209 was the dominating BFRs in hair and serum samples from the e-waste area, while DBDPE was the major BFRs from the urban area. Statistically significant correlations were observed between hair level and serum level for some substances (BDE209, DBDPE, BDE99, BDE47, BDE28, and BDE17), although the PBDE congener profiles in hair were different from those in the serum. A statistically significant positive correlation between the PBDE concentrations and the working age, as well as gender difference, was observed in e-waste workers. Different sources of PBDEs and DBDPE in three groups were identified by principal component analysis and spearman correlation coefficient. Hair is suggested to be a useful matrix for biomonitoring the PBDE exposure in humans.     

Evaluation of spatial distribution and accumulation of novel brominated flame retardants,HBCD and PBDEs in an Italian subalpine lake using zebra mussel (Dreissena polymorpha)

Because of the reduction in the use of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), novel brominated flame retardants (NBFRs), including 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB), and pentabromoethylbenzene (PBEB), started to be marketed as alternatives to the banned formulations. In this study, the spatial distribution and accumulation of NBFRs, PBDEs, and HBCD in the biota have been investigated in the littoral compartment of a large and deep subalpine lake (Lake Maggiore, Northern Italy), using zebra mussel Dreissena polymorpha and roach (Rutilus rutilus) as bioindicators. To our knowledge, this is the first study reporting the contamination of NBFRs in the freshwater invertebrate D. polymorpha. Contamination of zebra mussel due to PBEB, HBB, and BTBPE was low, ranging from 0.9 to 2.9 ng/g lipid weight, from 1.1 to 2.9 ng/g l.w., and from 3.5 to 9.5 ng/g l.w., respectively. PBEB and BTBPE in roach were always below the detection limit, while the contamination of HBB ranged from < limits of detection (LOD) to 1.74 ng/g l.w., indicating a weak contamination. DBDPE was < LOD in all the considered biological samples. Finally, HBCD was detected in all organic tissues with mean concentrations up to 74.4 ng/g l.w. PBDE results, supported by principal component analysis elaboration, suggested a possible contamination due to the congeners composing the penta- and deca-BDE technical formulations, which are present in the Lake Maggiore basin. The biomagnification factor values showed that tetra- and penta-BDE biomagnified, while octa-, nona-, and deca-BDE were still bioavailable and detectable in the fish muscles, but they do not biomagnified. Considering the other BFRs, only HBCD showed a moderate biomagnification potential.     

State of polybrominated diphenyl ethers in China: an overview

Polybrominated diphenyl ethers (PBDEs), extensively used as flame retardants, are ubiquitous environmental contaminants that are found in both abiotic and biotic environmental samples. Sufficient evidence shows that PBDEs have been rapidly accumulating in the environment of China, especially in the Southeast regions. This paper summarizes and critically reviews the published scientific data on PBDEs in China, including the levels of PBDEs in the air, soil, water, sediment, the terrestrial and marine organisms, and human samples in China. The data preliminarily reveal the state of PBDEs in China.     

Characterization of mass-labeled [13C14]-decabromodiphenylethane and its use as a surrogate standard in the analysis of sewage sludge samples

Very little data is available about the presence of the brominated flame retardant, DBDPE, in the environment. This study reports the characterization of [(13)C(14)]-decabromodiphenylethane and the use of this surrogate standard to positively identify and quantify the presence of DBDPE in sewage sludge samples. The large difference in response factors between BDE-209 and DBDPE predicates the use of [(13)C(14)]-decabromodiphenylethane as a surrogate standard to improve the accuracy when determining the levels of DBDPE in environmental samples.     

Levels,profile and distribution of Dechloran Plus (DP) and Polybrominated Diphenyl Ethers (PBDEs) in the environment of Pakistan

No scientific data is available on emerging contaminants including Polybrominated Diphenyl Ethers (PBDEs) and Dechloran Plus (DP) levels in the environment in Pakistan. Levels of PBDEs and DP were determined in the soil, sediment and atmospheric samples along the stretch of River Ravi in Punjab Province. Average concentrations of ΣPBDEs in atmosphere, soils and sediments were 36 pg m⁻³, 40 ng g⁻¹ and 640 ng g⁻¹. BDE-209 was the most abundant PBDE congener, showing that deca-BDE accounts for most of the total PBDE emitted in the environment of Pakistan. Total DP levels were calculated as 88 pg m⁻³, 0.8 ng g⁻¹ and 1.9 ng g⁻¹ in air, soil and sediment samples, respectively. The lower average fractions of anti-DP showed significant differences to those of the technical mixtures, indicating the lack of DP production source in Pakistan.     

Polybrominated diphenyl ethers (PBDEs) in sediment and bivalves from Korean coastal waters

Concentrations of polybrominated diphenyl ethers (PBDEs) were determined in sediment and bivalves collected from 25 coastal locations in Korea. Twenty major PBDE congeners were found in all sediment and bivalve samples. SigmaPBDE20 concentrations ranged from 0.45 to 494 ng/g, dry weight (average 27.8 ng/g dry weight) in sediments, and from 0.38 to 9.19 ng/g, wet weight (average 2.94 ng/g wet weight) in bivalves. The highest concentrations were found at locations near industrial complexes and large harbors, suggesting that human activities contribute to PBDEs contamination in Korean coastal environment. PBDE concentrations measured in our study, excluding BDE congener 209 (deca-BDE), in sediment and bivalves were lower than those reported from other countries; whereas BDE 209 concentrations were comparable to or higher than those reported from other countries. The predominant PBDE congener in sediments and bivalves was deca-BDE, which accounted for >90% and >60% of the total PBDE concentrations in sediment and bivalves, respectively. This is consistent with high consumption of deca-BDE for the flame-retardant market in Korea. Significant correlations existed among BDEs 28, 47, 99, 100, 153 and 154 in sediments and bivalves; however, BDEs 183 and 209 showed little correlation compared with less highly brominated congeners.     

Polybrominated diphenyl ethers (PBDEs) and alternative brominated flame retardants in air and seawater of the European Arctic

The spatial distribution of polybrominated diphenyl ethers (PBDEs) and several alternative non-PBDE, non-regulated brominated flame retardants (BFRs) in air and seawater and the air-seawater exchange was investigated in East Greenland Sea using high-volume air and water samples. Total PBDE concentrations (Ó₁₀PBDEs) ranged from 0.09 to 1.8 pg m⁻³ in the atmosphere and from 0.03 to 0.64 pg L⁻¹ in seawater. Two alternative BFRs, Hexabromobenzene (HBB) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), showed similar concentrations and spatial trends as PBDEs. The air-seawater gas exchange was dominated by deposition with fluxes up to −492 and −1044 pg m⁻² day⁻¹ for BDE-47 and DPTE, respectively. This study shows the first occurrence of HBB, DPTE and other alternative flame retardants (e.g., pentabromotoluene (PBT)) in the Arctic atmosphere and seawater indicating that they have a similar long-range atmospheric transport potential (LRAT) as the banned PBDEs.     

Levels and bioaccumulation of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in fishes from the Pearl River estuary and Daya Bay, South China

Fifty fish samples were collected from the Pearl River estuary (PRE) and Daya Bay, South China and were analyzed for DDTs, HCHs, chlordanes and polybrominated biphenyl ethers (PBDEs). Except the high concentrations of DDT observed in fishes, the concentrations of HCHs, chlordanes and PBDEs were low when compared to other regions. BDE-47 was the predominant PBDE congener and the BDE-209 concentrations were relatively low, despite its high concentration in surface sediments. The absence of significant increase of DDT, HCH, chlordane and PBDE concentrations towards higher delta15N values, as well as the lack of a significant correlation (p<0.1) between log concentrations (lipid normalized) and delta15N, may indicate a weak biomagnification of these chemicals in the food webs. Good agreement was observed between their concentrations and lipid contents of the organisms. Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms in the studied subtropical waters.     

Levels and body distribution of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in freshwater fishes from the Yangtze River, China

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) were determined in muscle, liver and eggs of freshwater fishes from the lower reach of the Yangtze River, China. The present study is the first to report HBCD concentrations in the environment of China. The concentrations of PBDEs and HBCDs in muscle of freshwater fishes from the Yangtze River ranged from 18 to 1100ng/g and 12 to 330ng/g lipid weight (wt.), respectively. When compared with other regions of the world, the contamination of PBDEs in biota could be regarded as moderate, whereas contamination of HBCDs in biota was relatively high. The PBDE congener profiles in fishes of the present study were markedly different from those observed in freshwater and marine fishes from other regions of the world. In the present study, BDE-15, BDE-28 and BDE-47 were the predominant congeners in the fishes. This particular congener profile in fishes from the Yangtze River revealed that a specific commercial PBDE formulation (probably made in China) might have been used in the Yangtze River Delta region.     

Halogenated organic contaminants (HOCs) in sediment from a highly eutrophicated lake, China: Occurrence, distribution and mass inventories

Halogenated organic contaminants (HOCs) including 16 polybrominated diphenyl ethers (PBDEs) and 37 polychlorinated biphenyls (PCBs) were determined in 49 surfacial sediments from Chaohu Lake, a highly eutrophicated lake, China. PBDEs were detected in almost samples with the range of the total concentration (defined as Σ₁₆PBDEs) from 0.84 to 86.6 ng g⁻¹. Compared with the occurrence of PBDEs in Pearl River Delta and Yangtze River Delta in China, lower percentage of BDE-209 over the concentration of Σ₁₆PBDEs was inferred by the high-volume application of penta-BDE mixture product for local domestic furniture purpose. The total concentration of 37 PCBs (Σ₃₇PCBs) ranged from 0.05 to 3.36 ng g⁻¹ with the most detection of PCB-1, -4, -52 and -71. Both the concentrations of Σ₁₆PBDE and Σ₃₇PCB poorly correlated with total organic carbon (TOC), suggesting the significant contribution of phytoplankton organic carbons to sediment TOC. The contamination by PBDEs and PCBs in western region of the lake was significantly more serious than in eastern lake. Our findings about the higher residues of PBDEs and PCBs in sediments at the estuary of Nanfei River compared to the other estuaries also supported the conclusion that urban area (Hefei city) was the main source of PBDEs and PCBs. The comparison with the concentration of HOC in the present study with those in other lacustrine sediments around the world suggested the contamination by PBDEs in Chaohu Lake is at middle of the global concentration range, whereas PCBs is at low end of the global range which could be elucidated by local economic development and historical usage of PBDEs and PCBs. The mass inventories of HOCs in the lake were estimated at 561 and 38 kg, which corresponds to only 0.000006% and 0.0001% of these global historical produce volumes, respectively.     

A national survey of polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in Chinese mothers' milk

Seven polybrominated diphenyl ethers (PBDEs) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) congeners (CB-28, CB-52, CB-101, CB-138, CB-153 and CB-180) were measured in 24 pooled human milk samples comprised of 1237 individual samples from 12 provinces in China. The samples were taken to estimate the background body burden of general population and assess nursing infant exposure via human milk in China. The median concentrations of ∑₇PBDEs and ∑₆PCBs were 1.49 and 10.50 ng g⁻¹ lipid weight (lw), respectively. BDE-28, BDE-47 and BDE-153 were predominant PBDE congeners accounting for nearly 70% of ∑₇PBDEs. As for indicator PCBs, CB-153 was the most abundant congener, followed by CB-138. In our study, there was no significantly statistical relationship between concentrations of PBDEs in milk samples and maternal age as well as dietary habits. ∑₇PBDEs did not correlate to ∑₆PCBs in Chinese mothers’ milk. The human exposure to indicator PCBs in China was found to be significantly determined by maternal age, dietary habits and geographical factors. It is suggested that Chinese general population is probably exposed to PBDEs with multiple sources and pathways. The estimated daily intakes (EDI) of BDE-47, BDE-99 and BDE-153 for the Chinese nursing infant were much lower than corresponding threshold reference values suggested by USEPA.     

Polybrominated diphenyl ethers in sediments of the Daliao River Estuary, China: levels, distribution and their influencing factors

The concentrations, compositional profiles, possible sources of polybrominated diphenyl ethers (PBDEs) in sediments of the Daliao River Estuary as well as the factors influencing the distribution of PBDEs were investigated. The total concentrations of PBDEs ranged from 0.13 to 1.98 ng g⁻¹ d.w. BDE209 was the dominating congener in all sediment samples, indicating the pollution of PBDEs in the Daliao River Estuary mainly came from the use of deca-BDE commercial mixtures. The intrusion of sea waters promoted the deposition of the colloid-associated PBDEs in the estuary. There were significantly negative correlations between PBDE concentration in sediment with pH value and salinity in the bottom water. The higher river flow in the flood season (summer) obviously accelerated the transport of PBDEs, and thereby increased the risk of PBDE contamination to the deep ocean. Moreover, a positive correlation between TOC and PBDE distributions was observed, suggesting that TOC regulated the distributions of PBDEs in sediments of Daliao River Estuary.     

Contamination and potential sources of polybrominated diphenyl ethers (PBDEs) in water and sediment from the artificial Lake Shihwa, Korea

Concentrations of polybrominated diphenyl ethers (PBDEs) were determined in water and sediment collected from the artificial Lake Shihwa and surrounding creeks. Total concentrations of 23 PBDE congeners in water and sediment ranged from 0.16 to 11.0 ng L⁻¹ and from 1.3 to 18 700 ng g⁻¹ dry weight, respectively. The concentrations of BDE 209 in water and sediment were 1-2 orders of magnitude higher than the total concentrations of other PBDE congeners. The concentrations of total PBDEs and BDE 209 in sediments were the highest compared to previously reported worldwide levels. The highest concentrations of PBDEs in water and sediments were found in creeks near industrial complexes. The PBDE concentrations gradually decreased with increasing distance from the creeks to the inshore and then offshore regions of the lake. BDE 209 was a major congener, accounting for 80% of the total PBDEs in water and sediment, consistent with a high consumption of deca-BDE for the brominated flame retardant market in Korea. Non-parametric multidimensional scaling ordination showed that surrounding creeks are major pathways of PBDE contamination associated with deca-BDE technical mixtures used in industrial complexes around Lake Shihwa. A significant correlation between total organic carbon and total PBDE concentration was found in sediments, and the correlation coefficients for individual PBDE congeners relatively increased from lower to higher brominated congeners.     

Levels and distributions of polybrominated diphenyl ethers,hexabromocyclododecane, and tetrabromobisphenol A in sediments from Taihu Lake,China

The concentrations and distribution of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA) were investigated in 28 sediment samples collected from Taihu Lake, Eastern China. The results showed that all three classes of compounds were detected in 28 sediment samples but that PBDEs were the main contaminants in the study area. The total PBDE concentrations ranged from 3.77 to 347 ng/g dry weight (dw) with a mean value of 72.8 ng/g dw, whereas the concentrations ranged from 0.168 to 2.66 and from 0.012 to 1.30 ng/g dw for HBCD and TBBPA, respectively. In all of the sediment samples, BDE-209 was the predominant congener, accounting for 95.9 to 98.6 % of the total PBDEs, which indicated that commercial mixtures of deca-BDEs were the main sources of PBDE contamination. Higher concentrations of PBDEs were found in samples collected from Meiliang Bay and Gonghu Bay near the inflow river, which suggested that inflow runoff might play an important role in the PBDE levels in Taihu Lake sediments.