Based on the location of bromine substituents and conjugation matrix, a new substituent po- sition index ~X not only was defined, but also molecular shape indexes Km and electronega- tivity distance vectors Mm of diph...Based on the location of bromine substituents and conjugation matrix, a new substituent po- sition index ~X not only was defined, but also molecular shape indexes Km and electronega- tivity distance vectors Mm of diphenylamine and 209 kinds of polybrominated diphenylamine （PBDPA） molecules were calculated. Then the quantitative structure-property relationships （QSPR） among the thermodynamic properties of 210 organic pollutants and 0X, K3, M29, M36 were founded by Leaps-and-Bounds regression. Using the four structural parameters as input neurons of the artificial neural network, three satisfactory QSPR models with network structures of 4：21：1, 4：24：1, and 4：24：1 respectively, were achieved by the back-propagation algorithm. The total correlation coefficients R were 0.9999, 0.9997, and 0.9995 respectively and the standard errors S were 1.036, 1.469, and 1.510 respectively. The relative mean deviation between the predicted value and the experimental value of Sθ, AfHe and △fGθ- were 0.11%, 0.34% and 0.24% respectively, which indicated that the QSPR models had good stability and superior predictive ability. The results showed that there were good nonlinear correlations between the thermodynamic properties of PBDPAs and the four structural pa- rameters. Thus, it was concluded that the ANN models established by the new substituent position index were fully applicable to predict properties of PBDPAs.展开更多
Nineteen surface sediment samples collected from Baiyangdian Lake and its inflowing river （Fuhe River） in North China were analyzed for polybrominated diphenyl ethers （PBDEs） and decabromodiphenylethane （DBDPE）....Nineteen surface sediment samples collected from Baiyangdian Lake and its inflowing river （Fuhe River） in North China were analyzed for polybrominated diphenyl ethers （PBDEs） and decabromodiphenylethane （DBDPE）. The concentrations of PBDEs and DBDPE in sediments ranged from 5.5 to 300.7 ng/g dry weight （dw） and 1.1 to 68.2 ng/g dw, respectively. Their levels in sediments in Fuhe River were significantly higher than those in Balyandian Lake. Compared to data from other regions, the PBDE levels in surface sediments from Baiyangdian Lake and Fuhe River were in the medium to lower range. Among the PBDE congeners, BDE209 was predominant, with contributions to the total PBDEs ranging from 79.4% to 97.3% in sediment samples. For the lowly brominated congeners （tri- to hepta-BDE）, BDE47 and BDE99 were the most abundant, which contributed 52.1% and 44.1% to the sum of tri- to hepta-BDEs in the sediments from Baiyangdian Lake and Fuhe River, respectively. The compositional patterns of PBDEs in Baiyangdian Lake sediments indicated that technical deca-BDE mixture was the major pollutant sources with a minor contribution of penta-BDE mixture. The present study suggested that the importance of Fuhe River as a possibly potential sources of PBDEs contamination in Baiyangdian Lake.展开更多
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...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.展开更多
Polybrominated diphenyl ethers （PBDEs） were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of ∑11PBDE were 0.017-1.17 ng/m3 ...Polybrominated diphenyl ethers （PBDEs） were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of ∑11PBDE were 0.017-1.17 ng/m3 in gaseous phase, 0.5-161.1 ng/m3 in particulate phase, and 73-2629 ng/g dry weight in soil samples. The PBDE congener pattern in the gaseous phase differed from that in the particulate phase, and the PBDE congener pattern in the particulate phase was similar with that in soil. This demonstrated that there was little difference with atmospheric particle-soil transfer efficiency among PBDE congeners. In addition, there were seasonal variations in percentages on particle for lower brominated congeners. The BDE-28 was mostly in the gaseous phase in summer （88.3%）, whereas the average proportion of BDE-28 in gaseous phase in winter was 38.9%. Higher brominated congeners （i.e., BDE-206, BDE- 207, BDE-208, and BDE-209） were bound to the atmospheric particulate phase, and their potentials for long-range migration were mainly affected by the environmental behavior of atmospheric particles. Results indicated that PBDE congeners in summer were closer to gas-particle partition equilibrium than in winter. Temperature should be considered the main factor causing nonequilibrium in winter.展开更多
The levels and distributions of polybrominated diphenyl ethers （PBDEs） in chicken tissues from an electronic waste （e-waste） recycling area in southeast China were investigated. Human dietary intake by local resid...The levels and distributions of polybrominated diphenyl ethers （PBDEs） in chicken tissues from an electronic waste （e-waste） recycling area in southeast China were investigated. Human dietary intake by local residents via chicken muscle and eggs was estimated. The mean PBDEs concentrations in tissues ranged from 15.2 to 3138.1 ng/g lipid weight （lw） and in egg the concentration was 563.5 ng/g lw. The results showed that the level of total PBDEs （∑PBDEs） in the chicken tissue was 2-3 orders of magnitude higher than those reported in the literature. The large difference of ∑PBDEs concentrations between tissues confirmed that the distribution of PBDEs in tissues depend on tissue-specificity rather than the ＂lipid-compartment＂. BDE-209 was the predominant congener （82.5%- 94.7% of ∑PBDEs） in all chicken tissues except in brain （34.7% of ∑PBDEs）, which indicated that deca-BDE （the major commercial PBDE formulation comprising 65%-70% of total production） was major pollution source in this area and could be bioaccumulated in terrestrial animals. The dietary PBDEs intake of the local residents from chicken muscle and egg, assuming only local bred chickens and eggs were consumed, ranged from 2.2 to 22.5 ng/（day.kg body weight （bw）） with a mean value of 13.5 ng/（day-kg bw）, which was one order of magnitude higher than the value reported in previous studies for consumption of all foodstuffs.展开更多
To understand potential ecotoxicological effects of electrical and electronic equipment waste （e-waste） recycling and polybrominated diphenyl ethers （PBDEs） bioaccumulation in loaches, a semi-field experiment usin...To understand potential ecotoxicological effects of electrical and electronic equipment waste （e-waste） recycling and polybrominated diphenyl ethers （PBDEs） bioaccumulation in loaches, a semi-field experiment using Chinese loach （Misgurnus anguiUicaudatus） as experimental fish was performed. Larval loaches were kept in net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site （27%, 19/70） and from reference site （70%, 49/70）. Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers （PBDEs）, the main pollutants in e-waste, in loaches was also studied, the mean concentration of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L （dissolved phase）. BDE 209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE 209 （less than 0.01% of total PBDEs） and high concentration of BDE47 （up to 39.34% of total PBDEs） were detected in loaches.展开更多
Areas containing industrial facilities belonging to three different typical industries that may cause pollution by polybrominated diphenyl ethers （PBDEs） in Beijing, China were investigated. Specifically, the areas ...Areas containing industrial facilities belonging to three different typical industries that may cause pollution by polybrominated diphenyl ethers （PBDEs） in Beijing, China were investigated. Specifically, the areas contained a solid waste incineration plant, a chemical factory, and a heat and power plant. Investigation of the pollution status of PBDEs in the surface soil from areas around these industries revealed the highest concentration of 42 PBDE congeners （118 ng/g, dry mass） at the solid waste incineration plant. In the other two plants, the highest concentrations were both 26 ng/g （dry mass）. Among the PBDE homologues, the PBDE contamination at all sites showed similar congener compositions, with BDE 209 being the dominant congener. Our findings established the first contamination status of three typical industrial areas in Beijing. Furthermore, the total concentrations of 42 PBDE congeners tended to decrease as the distance from the investigated plants increased. Overall, these plants were identified as potential pollution sources of PBDEs in Beijing. Moreover, Pearson correlation analysis revealed that the major PBDE source in Beijing may be associated with the technical deca-BDE and penta-BDE mixture. Based on the data obtained in this preliminary investigation, further study of the potential of these sources to emit PBDEs in Beijing is warranted.展开更多
Uptake, translocation and debromination of three polybrominated diphenyl ethers （PBDEs）, BDE-28, -47 and -99, in maize were studied in a hydroponic experiment. Roots took up most of the PBDEs in the culture solution...Uptake, translocation and debromination of three polybrominated diphenyl ethers （PBDEs）, BDE-28, -47 and -99, in maize were studied in a hydroponic experiment. Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability. PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants. Furthermore, PBDE concentrations decreased from roots to stems and then to leaves, and a very clear decreasing gradient was found in segments upwards along the stem. These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize. More highly brominated PBDEs were translocated with more difficulty. Radial translocation of PBDEs from nodes to sheath inside maize was also observed. Both acropetal and radial translocations were enhanced at higher transpiration rates, suggesting that PBDE transport was probably driven by the transpiration stream. Debromination of PBDEs occurred in all parts of the maize, and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences. This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants, elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.展开更多
Polybrominated diphenyl ethers （PBDEs） as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study...Polybrominated diphenyl ethers （PBDEs） as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study was to investigate the PBDEs exposure of children （9–12 years） from Taizhou, China. Fifty-eight blood samples were collected in one school in a mountainous area in Taizhou. The concentrations of ∑9PBDEs （sum of BDE-28, -47, -99, -100, -153, -154, -183, -197 and -209） ranged from 2.66 to 33.9 ng/g lipid wet （lw） with a median of 7.22 ng/g lw. These concentrations were lower than those of children in USA, but close to European and Asian general population levels. The results showed that children in Taizhou countryside were at a low level of PBDEs exposure. The predominant congener was BDE-209, followed by BDE-28, -47, -197 and -153. High abundance of BDE-209 was consistent with the pollution background of PBDEs in China characterized by high brominated congeners as main pollutants.展开更多
Polybrominated diphenyl ethers（PBDEs） are commercial flame retardants that have been commonly used in vehicle interior to reduce fire-related hazards. Due to high temperatures and intense insolation that can be atta...Polybrominated diphenyl ethers（PBDEs） are commercial flame retardants that have been commonly used in vehicle interior to reduce fire-related hazards. Due to high temperatures and intense insolation that can be attained inside cars parked in the sun, additive PBDEs are prone to leach out and attach to in-vehicle dust, as well as to photo-debrominate. This study examines seasonal variations of concentrations of three common PBDE congeners（BDE-47, BDE-99 and BDE-209） in car dust in Israel. The overall concentrations of these BDEs ranged from 1 to 29 μg/g, and were higher in the summer than in the winter（average of 10.2 and5.3 μg/g, respectively）. Congener-specific concentrations showed distinct seasonal pattern,representing the interplay between leaching, evaporation and photodebromination. Photolysis of the three congeners, while adsorbed on glass filters and exposed to solar radiation, revealed first order kinetics with debromination rates on the order of 10-2/min. Hence, seasonal variations of the meteorological conditions were found to affect the in-vehicle PBDE concentrations, and are therefore expected also to affect the exposure of passengers to PBDEs.展开更多
We measured 39 polybrominated diphenyl ethers （PBDEs） in the muscle tissue of three species of fish （Sciaenops ocellatus,Sparus macrocephalus,and Lateolabrax japonicus） and four species of shellfish （Tegillarca g...We measured 39 polybrominated diphenyl ethers （PBDEs） in the muscle tissue of three species of fish （Sciaenops ocellatus,Sparus macrocephalus,and Lateolabrax japonicus） and four species of shellfish （Tegillarca granosa,Cyclina sinensis,Sinonovacula constricta,and Ostrea cucullata） that were collected downstream of electronic-waste recycling plants in Taizhou,China.A total of 24 PBDE congeners （PBDE 24） in the samples were detected.The PBDE 24 （total PBDE） ranged from 545.4 to 1688.7 ng/kg ww （wet weight）.The mean PBDE 24 concentration was 1382.6 ng/kg ww in fish and 858.1 ng/kg ww in shellfish.The lower brominated congeners were detected at relatively high concentrations in all species.The penta-products,produced from e-waste,were found at relatively low levels.A principal component analysis suggested a significant correlation among di-,tri-,tetra-,and hepta-BDEs for the three species of fish.Similarly,we found a significant correlation between mono-and tri-BDEs in the shellfish.Our results suggested that the processes of PBDE metabolism and elimination were similar in both fish and shellfish.In addition,the primary source of PBDEs appeared to be from the debromination of high brominated PBDEs.展开更多
Objective：To investigate the metabolites of polybrominated diphenyl ether 99（BDE-99）and its related cytochrome P450s in an in vitro system.Methods：Rat primary hepatocytes were isolated and treated with BDE-99 for ...Objective：To investigate the metabolites of polybrominated diphenyl ether 99（BDE-99）and its related cytochrome P450s in an in vitro system.Methods：Rat primary hepatocytes were isolated and treated with BDE-99 for 24-72 h.Metabolites were then extracted from the hepatocytes and media,and detected by GC/MS.Several mRNAs of metabolic enzymes were also extracted from the same cells and the gene expression levels were determined using quantitative real-time PCR.In addition,selected recombinant cytochrome P450s（CYPs） were expressed in a bacurovirus/sf9 system,and these were further used to explore the metabolism of BDE-99 in vitro.The parent depletion approach was used for screening the ability of CYPs to eliminate BDE-99.Results： A reductively debrominated metabolite,BDE-47,and three oxidative metabolites,2,4,5-tribromophenol,5-OH-BDE-47,and 5＇-OH-BDE-99,were identified from the BDE-99-treated rat hepatocytes,whereas no MeO metabolite was detected in the system.RT-PCR analysis showed that CYP 3A23/3A1,1A2,and 2B1/2 were induced by BDE-99.Furthermore,using the heterological expressed CYP proteins in in vitro BDE-99 metabolism experiments we found that CYP1A2 and CYP3A4 showed the highest metabolic efficiency for BDE-99,with the metabolic clearance rates of CYP1A2 and CYP3A4 being 30.3%and 27.7%,respectively.CYP1A1 and CYP2A6 displayed relatively low clearance rates,while CYP2E1 seemed not to be associated with the BDE-99 metabolism.Conclusions：In our in vitro rat primary hepatocyte metabolism system,four metabolites of BDE-99 were identified,and CYP3A4 and CYP1A2 were demonstrated to be involved in the BDE-99 metabolism.展开更多
To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here...To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here, this method was adapted to determine the bioaccessibility of PBDEs in dust and the digestion conditions that influenced the bioaccessibility of PBDEs were optimized. The digestion conditions included the incubation time of dust in the intestinal digestion solution （T）, the bile concentration in the intestinal digestion solution （Chile）, and the ratio of the volume of the intestinal digestion solution to dust （R）. The influence of the concentrations of individual PBDE congeners （CpBDE） on the bioaccessibility of PBDEs was also investigated. Cetral composite design was used to build an experimental model and set experimental parameters, and response surface methodology was used to analyze the obtained data. The results showed that the bioaccessibility of PBDEs increased with the increases of Chile and R, and was independent of T and CpSDE. Under the digestion conditions with Chile and R being at 4.0-7.0 g/L and 150-250, respectively, the bioaccessibility of PBDEs in the method-dust varied from 39.2% to 72.8%, which were comparable with the bioaccessibility or bioavailability of PBDEs in dust/soil in the literature. Thus, the in vitro method to measure the bioaccessibility of PBDEs in dust was established and validated. Finally, the bioaccessibility of PBDEs in four natural dust samples, which ranged from 36.1% to 43.3%, were determined using the adapted method.展开更多
The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The isodesmic reactions were d...The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation（△fHθ） and standard free energy of formation（△fGθ） of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution（NPBS） were discussed,and it was found that there exist high correlation between thermodynamic parameters（entropy（Sθ）,△fHθ and △fGθ） and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure（Cp,m） from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature（T,T^1 and T^2） for almost all PBXTH congeners.展开更多
This review focuses on the occurrence and interactions of engineered nanoparticles(ENPs)and brominated flame retardants(BFRs)such as polybrominated diphenyl ethers(PBDEs)in water systems and the generation of highly c...This review focuses on the occurrence and interactions of engineered nanoparticles(ENPs)and brominated flame retardants(BFRs)such as polybrominated diphenyl ethers(PBDEs)in water systems and the generation of highly complex compounds in the environment.The release of ENPs and BFRs(e.g.PBDEs)to aquatic environments during their usage and disposal are summarised together with their key interaction mechanisms.The major interaction mechanisms including electrostatic,van derWaals,hydrophobic,molecular bridging and steric,hydrogen andπ-bonding,cation bridging and ligand exchange were identified.The presence of ENPs could influence the fate and behaviour of PBDEs through the interactions as well as induced reactions under certain conditions which increases the formation of complex compounds.The interaction leads to alteration of behaviour for PBDEs and their toxic effects to ecological receptors.The intermingled compound(ENPs-BFRs)would show different behaviour from the parental ENPs or BFRs,which are currently lack of investigation.This review provided insights on the interactions of ENPs and BFRs in artificial,environmental water systems and wastewater treatment plants(WWTPs),which are important for a comprehensive risk assessment.展开更多
The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） wit...The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.展开更多
Concentrations of 16 polybrominated diphenyl ether（PBDE） congeners were measured in river sediments, paddy soils and three species of paddy-field organisms（crab, loach and carp） collected from the Liaohe River Bas...Concentrations of 16 polybrominated diphenyl ether（PBDE） congeners were measured in river sediments, paddy soils and three species of paddy-field organisms（crab, loach and carp） collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs（∑_（16）PBDEs） in sediments and paddy soils were in the ranges of 273.4–3246.3 pg/g dry weight（dw）, and 192.1–1783.8 pg/g dw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑_（16）PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota–soil accumulation factor（BSAF） was calculated as the ratio between the lipid-normalized concentration in paddyfield organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab（3.6） 〉 loach（3.3） 〉 carp（2.1）. BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their log KOWvalues was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern.展开更多
Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the relative retention time （RRT） of polybrominated diphenyl ethers （PBDEs） were predic...Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the relative retention time （RRT） of polybrominated diphenyl ethers （PBDEs） were predicted. A four-variable regression model （M30） with the correlation coefficient of 0.9816 and the root mean square errors of 0.061 was developed using a training set including 30 PBDEs. The correlation coefficient of 0.9841 and the root mean square errors of 0.054 between the values of RRT predicted by M30 and the RRT observed for 16 external PBDEs show a good predictive potential of M30. The descriptors included in the M30 represent four interactions between four pairs of atom types, i.e., atom -C= and -C=, -C= and 〉C=, 〉C= and 〉C=, -C= and -Br.展开更多
This pilot study documented the occurrence and levels of brominated flame retardants in the tissues of farmed and wild salmon in southern Chile.Samples of Coho salmon and rainbow trout were obtained from fish farms,ri...This pilot study documented the occurrence and levels of brominated flame retardants in the tissues of farmed and wild salmon in southern Chile.Samples of Coho salmon and rainbow trout were obtained from fish farms,rivers and lakes in the Patagonia in Aysen Region,Chile.The samples were analyzed by Gas Chromatography Negative Chemical Ionization Mass Spectrometry for the different polybrominated diphenyl ether（PBDE） congeners.Contaminants were observed in all the samples,and the congeners BDE 17,28,47 and 66 were observed in all both farmed and wild samples.The concentrations were higher in the farmed Coho salmon,presenting significant differences with wild salmon.The levels reached 182 pg/g wet weight（ww） vs.120 ww.In the case of the rainbow trout,the concentrations were lower,although the congener profile was quite similar.The levels reached an average of 100 pg/g ww in the farmed fish versus 110 pg/g ww in wild fish,and no significant difference was observed between the species.In both species,the congener with the highest concentration was BDE 47.Based on this information,the BDE ？ow was estimated for commerce,which is a form of pollutant transport not usually considered in POP pollution studies.A preliminary estimation indicated that the quantity of PBDEs mobilized by commerce was in the order of kg,and in the case of Chile might reach almost 1 kg.展开更多
Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils.The key to the development of leaching technology is selective removal of targeted pollutants in soil washing e...Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils.The key to the development of leaching technology is selective removal of targeted pollutants in soil washing effluent and recycling of surfactant solutions.In this study,a molecular imprinting technique was applied to selectively sorb polybrominated diphenyl ethers(PBDEs)in soil washing effluent.The novel molecular imprinted polymers(MIPs)using different template molecules were synthesized by precipitation polymerization.Adsorption behaviors andmechanisms ofMIPs were studied through experiments and theoretical calculations.The results show that 4-bromo-4'-hydroxybiphenyl and toluene can be effective imprinting molecule for MIPs synthesis.The maximal adsorption capacity of selected dummy molecular imprinted polymer(D1-MIP)was 1032.36μmol/g,and that of part molecular imprinted polymer(P-MIP)was 981.13μmol/g.Their imprinting factors in 5 PBDEs adsorption ranged from 2.13 to 5.88,the recovery percentage of Triton X-100 can reach 99.09%,confirming the feasibility of reusing surfactant.Various PBDEs could be removed by MIPs,and Quantitative Structure Property Relationship analysis revealed that PBDEs’molecular volume,planarity,polarity,and hydrophobicity have major influences on their adsorption performance.DFT calculation revealed that Van derWaals force and hydrogen bonding played important roles during selective adsorption.These results can provide effective theoretical guidance for surfactant enhanced soil elution in practical engineering applications.展开更多
文摘Based on the location of bromine substituents and conjugation matrix, a new substituent po- sition index ~X not only was defined, but also molecular shape indexes Km and electronega- tivity distance vectors Mm of diphenylamine and 209 kinds of polybrominated diphenylamine （PBDPA） molecules were calculated. Then the quantitative structure-property relationships （QSPR） among the thermodynamic properties of 210 organic pollutants and 0X, K3, M29, M36 were founded by Leaps-and-Bounds regression. Using the four structural parameters as input neurons of the artificial neural network, three satisfactory QSPR models with network structures of 4：21：1, 4：24：1, and 4：24：1 respectively, were achieved by the back-propagation algorithm. The total correlation coefficients R were 0.9999, 0.9997, and 0.9995 respectively and the standard errors S were 1.036, 1.469, and 1.510 respectively. The relative mean deviation between the predicted value and the experimental value of Sθ, AfHe and △fGθ- were 0.11%, 0.34% and 0.24% respectively, which indicated that the QSPR models had good stability and superior predictive ability. The results showed that there were good nonlinear correlations between the thermodynamic properties of PBDPAs and the four structural pa- rameters. Thus, it was concluded that the ANN models established by the new substituent position index were fully applicable to predict properties of PBDPAs.
基金supported by the National Basic Research Program(973) of China(No. 2006CB403306)the National Natural Science Foundation of China(No.30870311)
文摘Nineteen surface sediment samples collected from Baiyangdian Lake and its inflowing river （Fuhe River） in North China were analyzed for polybrominated diphenyl ethers （PBDEs） and decabromodiphenylethane （DBDPE）. The concentrations of PBDEs and DBDPE in sediments ranged from 5.5 to 300.7 ng/g dry weight （dw） and 1.1 to 68.2 ng/g dw, respectively. Their levels in sediments in Fuhe River were significantly higher than those in Balyandian Lake. Compared to data from other regions, the PBDE levels in surface sediments from Baiyangdian Lake and Fuhe River were in the medium to lower range. Among the PBDE congeners, BDE209 was predominant, with contributions to the total PBDEs ranging from 79.4% to 97.3% in sediment samples. For the lowly brominated congeners （tri- to hepta-BDE）, BDE47 and BDE99 were the most abundant, which contributed 52.1% and 44.1% to the sum of tri- to hepta-BDEs in the sediments from Baiyangdian Lake and Fuhe River, respectively. The compositional patterns of PBDEs in Baiyangdian Lake sediments indicated that technical deca-BDE mixture was the major pollutant sources with a minor contribution of penta-BDE mixture. The present study suggested that the importance of Fuhe River as a possibly potential sources of PBDEs contamination in Baiyangdian Lake.
基金supported by the National Natural Science Foundation of China (No. 41103054,40821003,41073081)the Earmarked Fund of the State Key Laboratory of Organic Geochemistry (No. OGL-200905)
文摘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.
基金supported by the National Natural Science Foundation of China (No. 20507023)the 985 Project of Minzu University of China (No. CUN985-3-3)the 111 Project of Minzu University of China (No. B08044)
文摘Polybrominated diphenyl ethers （PBDEs） were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of ∑11PBDE were 0.017-1.17 ng/m3 in gaseous phase, 0.5-161.1 ng/m3 in particulate phase, and 73-2629 ng/g dry weight in soil samples. The PBDE congener pattern in the gaseous phase differed from that in the particulate phase, and the PBDE congener pattern in the particulate phase was similar with that in soil. This demonstrated that there was little difference with atmospheric particle-soil transfer efficiency among PBDE congeners. In addition, there were seasonal variations in percentages on particle for lower brominated congeners. The BDE-28 was mostly in the gaseous phase in summer （88.3%）, whereas the average proportion of BDE-28 in gaseous phase in winter was 38.9%. Higher brominated congeners （i.e., BDE-206, BDE- 207, BDE-208, and BDE-209） were bound to the atmospheric particulate phase, and their potentials for long-range migration were mainly affected by the environmental behavior of atmospheric particles. Results indicated that PBDE congeners in summer were closer to gas-particle partition equilibrium than in winter. Temperature should be considered the main factor causing nonequilibrium in winter.
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-420-3,KZCX2-YW-Q-02-05)the National Natural Science Foundation of China (No.20437020,20677074)
文摘The levels and distributions of polybrominated diphenyl ethers （PBDEs） in chicken tissues from an electronic waste （e-waste） recycling area in southeast China were investigated. Human dietary intake by local residents via chicken muscle and eggs was estimated. The mean PBDEs concentrations in tissues ranged from 15.2 to 3138.1 ng/g lipid weight （lw） and in egg the concentration was 563.5 ng/g lw. The results showed that the level of total PBDEs （∑PBDEs） in the chicken tissue was 2-3 orders of magnitude higher than those reported in the literature. The large difference of ∑PBDEs concentrations between tissues confirmed that the distribution of PBDEs in tissues depend on tissue-specificity rather than the ＂lipid-compartment＂. BDE-209 was the predominant congener （82.5%- 94.7% of ∑PBDEs） in all chicken tissues except in brain （34.7% of ∑PBDEs）, which indicated that deca-BDE （the major commercial PBDE formulation comprising 65%-70% of total production） was major pollution source in this area and could be bioaccumulated in terrestrial animals. The dietary PBDEs intake of the local residents from chicken muscle and egg, assuming only local bred chickens and eggs were consumed, ranged from 2.2 to 22.5 ng/（day.kg body weight （bw）） with a mean value of 13.5 ng/（day-kg bw）, which was one order of magnitude higher than the value reported in previous studies for consumption of all foodstuffs.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No. KZCX2-YW-420-3)the National Basic Research Program (973) of China (No. 2003CB415005)the National Natural Science Foundation of China (No.20437020, 20677074)
文摘To understand potential ecotoxicological effects of electrical and electronic equipment waste （e-waste） recycling and polybrominated diphenyl ethers （PBDEs） bioaccumulation in loaches, a semi-field experiment using Chinese loach （Misgurnus anguiUicaudatus） as experimental fish was performed. Larval loaches were kept in net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site （27%, 19/70） and from reference site （70%, 49/70）. Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers （PBDEs）, the main pollutants in e-waste, in loaches was also studied, the mean concentration of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L （dissolved phase）. BDE 209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE 209 （less than 0.01% of total PBDEs） and high concentration of BDE47 （up to 39.34% of total PBDEs） were detected in loaches.
基金supported by the National Natural Science Foundation of China(No.21177148)
文摘Areas containing industrial facilities belonging to three different typical industries that may cause pollution by polybrominated diphenyl ethers （PBDEs） in Beijing, China were investigated. Specifically, the areas contained a solid waste incineration plant, a chemical factory, and a heat and power plant. Investigation of the pollution status of PBDEs in the surface soil from areas around these industries revealed the highest concentration of 42 PBDE congeners （118 ng/g, dry mass） at the solid waste incineration plant. In the other two plants, the highest concentrations were both 26 ng/g （dry mass）. Among the PBDE homologues, the PBDE contamination at all sites showed similar congener compositions, with BDE 209 being the dominant congener. Our findings established the first contamination status of three typical industrial areas in Beijing. Furthermore, the total concentrations of 42 PBDE congeners tended to decrease as the distance from the investigated plants increased. Overall, these plants were identified as potential pollution sources of PBDEs in Beijing. Moreover, Pearson correlation analysis revealed that the major PBDE source in Beijing may be associated with the technical deca-BDE and penta-BDE mixture. Based on the data obtained in this preliminary investigation, further study of the potential of these sources to emit PBDEs in Beijing is warranted.
基金supported by the National Basic Research Program (973) of China (No. 2009CB421603)the National Natural Science Foundation of China (No.40730740, 20921063, 20807048)
文摘Uptake, translocation and debromination of three polybrominated diphenyl ethers （PBDEs）, BDE-28, -47 and -99, in maize were studied in a hydroponic experiment. Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability. PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants. Furthermore, PBDE concentrations decreased from roots to stems and then to leaves, and a very clear decreasing gradient was found in segments upwards along the stem. These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize. More highly brominated PBDEs were translocated with more difficulty. Radial translocation of PBDEs from nodes to sheath inside maize was also observed. Both acropetal and radial translocations were enhanced at higher transpiration rates, suggesting that PBDE transport was probably driven by the transpiration stream. Debromination of PBDEs occurred in all parts of the maize, and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences. This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants, elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.
基金supported by the National Natural Science Foundation of China (No. 20677074, 20437020)the State Key laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences (No. KF2007-07, KF2008-11)
文摘Polybrominated diphenyl ethers （PBDEs） as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study was to investigate the PBDEs exposure of children （9–12 years） from Taizhou, China. Fifty-eight blood samples were collected in one school in a mountainous area in Taizhou. The concentrations of ∑9PBDEs （sum of BDE-28, -47, -99, -100, -153, -154, -183, -197 and -209） ranged from 2.66 to 33.9 ng/g lipid wet （lw） with a median of 7.22 ng/g lw. These concentrations were lower than those of children in USA, but close to European and Asian general population levels. The results showed that children in Taizhou countryside were at a low level of PBDEs exposure. The predominant congener was BDE-209, followed by BDE-28, -47, -197 and -153. High abundance of BDE-209 was consistent with the pollution background of PBDEs in China characterized by high brominated congeners as main pollutants.
基金supported by the Technion Center of Excellence in Exposure Science and Environmental Health (TCEEH), The Environmental Health Foundationthe Technion-Shantou University Collaboration in Environmental Health (No. 2015PG-ISL006)
文摘Polybrominated diphenyl ethers（PBDEs） are commercial flame retardants that have been commonly used in vehicle interior to reduce fire-related hazards. Due to high temperatures and intense insolation that can be attained inside cars parked in the sun, additive PBDEs are prone to leach out and attach to in-vehicle dust, as well as to photo-debrominate. This study examines seasonal variations of concentrations of three common PBDE congeners（BDE-47, BDE-99 and BDE-209） in car dust in Israel. The overall concentrations of these BDEs ranged from 1 to 29 μg/g, and were higher in the summer than in the winter（average of 10.2 and5.3 μg/g, respectively）. Congener-specific concentrations showed distinct seasonal pattern,representing the interplay between leaching, evaporation and photodebromination. Photolysis of the three congeners, while adsorbed on glass filters and exposed to solar radiation, revealed first order kinetics with debromination rates on the order of 10-2/min. Hence, seasonal variations of the meteorological conditions were found to affect the in-vehicle PBDE concentrations, and are therefore expected also to affect the exposure of passengers to PBDEs.
基金supported by the Wenling Science and Technology Bureau of Zhejiang Province (No. 2007-35)
文摘We measured 39 polybrominated diphenyl ethers （PBDEs） in the muscle tissue of three species of fish （Sciaenops ocellatus,Sparus macrocephalus,and Lateolabrax japonicus） and four species of shellfish （Tegillarca granosa,Cyclina sinensis,Sinonovacula constricta,and Ostrea cucullata） that were collected downstream of electronic-waste recycling plants in Taizhou,China.A total of 24 PBDE congeners （PBDE 24） in the samples were detected.The PBDE 24 （total PBDE） ranged from 545.4 to 1688.7 ng/kg ww （wet weight）.The mean PBDE 24 concentration was 1382.6 ng/kg ww in fish and 858.1 ng/kg ww in shellfish.The lower brominated congeners were detected at relatively high concentrations in all species.The penta-products,produced from e-waste,were found at relatively low levels.A principal component analysis suggested a significant correlation among di-,tri-,tetra-,and hepta-BDEs for the three species of fish.Similarly,we found a significant correlation between mono-and tri-BDEs in the shellfish.Our results suggested that the processes of PBDE metabolism and elimination were similar in both fish and shellfish.In addition,the primary source of PBDEs appeared to be from the debromination of high brominated PBDEs.
基金supported by 973 program(No.2009CB941701)NSFC grant(No.30972508)MOE Foundation for PhD Program(No 20093234110002)
文摘Objective：To investigate the metabolites of polybrominated diphenyl ether 99（BDE-99）and its related cytochrome P450s in an in vitro system.Methods：Rat primary hepatocytes were isolated and treated with BDE-99 for 24-72 h.Metabolites were then extracted from the hepatocytes and media,and detected by GC/MS.Several mRNAs of metabolic enzymes were also extracted from the same cells and the gene expression levels were determined using quantitative real-time PCR.In addition,selected recombinant cytochrome P450s（CYPs） were expressed in a bacurovirus/sf9 system,and these were further used to explore the metabolism of BDE-99 in vitro.The parent depletion approach was used for screening the ability of CYPs to eliminate BDE-99.Results： A reductively debrominated metabolite,BDE-47,and three oxidative metabolites,2,4,5-tribromophenol,5-OH-BDE-47,and 5＇-OH-BDE-99,were identified from the BDE-99-treated rat hepatocytes,whereas no MeO metabolite was detected in the system.RT-PCR analysis showed that CYP 3A23/3A1,1A2,and 2B1/2 were induced by BDE-99.Furthermore,using the heterological expressed CYP proteins in in vitro BDE-99 metabolism experiments we found that CYP1A2 and CYP3A4 showed the highest metabolic efficiency for BDE-99,with the metabolic clearance rates of CYP1A2 and CYP3A4 being 30.3%and 27.7%,respectively.CYP1A1 and CYP2A6 displayed relatively low clearance rates,while CYP2E1 seemed not to be associated with the BDE-99 metabolism.Conclusions：In our in vitro rat primary hepatocyte metabolism system,four metabolites of BDE-99 were identified,and CYP3A4 and CYP1A2 were demonstrated to be involved in the BDE-99 metabolism.
基金supported by the National Basic Research Program (973) of China (No. 2008CB418205)the Earmarked Fund of the State Key Laboratory of Organic Geochemistry (No. OGL-200903)+1 种基金the National Nature Science Foundation of China (No. 20807026,40830744)the Shanghai Leading Academic Disciplines (No. S30109)
文摘To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here, this method was adapted to determine the bioaccessibility of PBDEs in dust and the digestion conditions that influenced the bioaccessibility of PBDEs were optimized. The digestion conditions included the incubation time of dust in the intestinal digestion solution （T）, the bile concentration in the intestinal digestion solution （Chile）, and the ratio of the volume of the intestinal digestion solution to dust （R）. The influence of the concentrations of individual PBDE congeners （CpBDE） on the bioaccessibility of PBDEs was also investigated. Cetral composite design was used to build an experimental model and set experimental parameters, and response surface methodology was used to analyze the obtained data. The results showed that the bioaccessibility of PBDEs increased with the increases of Chile and R, and was independent of T and CpSDE. Under the digestion conditions with Chile and R being at 4.0-7.0 g/L and 150-250, respectively, the bioaccessibility of PBDEs in the method-dust varied from 39.2% to 72.8%, which were comparable with the bioaccessibility or bioavailability of PBDEs in dust/soil in the literature. Thus, the in vitro method to measure the bioaccessibility of PBDEs in dust was established and validated. Finally, the bioaccessibility of PBDEs in four natural dust samples, which ranged from 36.1% to 43.3%, were determined using the adapted method.
基金Supported by the NNSFC (20737001, 20977046)NSF of Zhejiang Province (2008Y507280)
文摘The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation（△fHθ） and standard free energy of formation（△fGθ） of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution（NPBS） were discussed,and it was found that there exist high correlation between thermodynamic parameters（entropy（Sθ）,△fHθ and △fGθ） and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure（Cp,m） from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature（T,T^1 and T^2） for almost all PBXTH congeners.
文摘This review focuses on the occurrence and interactions of engineered nanoparticles(ENPs)and brominated flame retardants(BFRs)such as polybrominated diphenyl ethers(PBDEs)in water systems and the generation of highly complex compounds in the environment.The release of ENPs and BFRs(e.g.PBDEs)to aquatic environments during their usage and disposal are summarised together with their key interaction mechanisms.The major interaction mechanisms including electrostatic,van derWaals,hydrophobic,molecular bridging and steric,hydrogen andπ-bonding,cation bridging and ligand exchange were identified.The presence of ENPs could influence the fate and behaviour of PBDEs through the interactions as well as induced reactions under certain conditions which increases the formation of complex compounds.The interaction leads to alteration of behaviour for PBDEs and their toxic effects to ecological receptors.The intermingled compound(ENPs-BFRs)would show different behaviour from the parental ENPs or BFRs,which are currently lack of investigation.This review provided insights on the interactions of ENPs and BFRs in artificial,environmental water systems and wastewater treatment plants(WWTPs),which are important for a comprehensive risk assessment.
基金Supported by the National Natural Science Foundation of China （20737001）.
文摘The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.
基金supported by the Chinese Public Welfare Projects on Environmental Protection (No. 201309030)the National Natural Science Foundation of China (Nos. 21077102 and 41201491)
文摘Concentrations of 16 polybrominated diphenyl ether（PBDE） congeners were measured in river sediments, paddy soils and three species of paddy-field organisms（crab, loach and carp） collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs（∑_（16）PBDEs） in sediments and paddy soils were in the ranges of 273.4–3246.3 pg/g dry weight（dw）, and 192.1–1783.8 pg/g dw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑_（16）PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota–soil accumulation factor（BSAF） was calculated as the ratio between the lipid-normalized concentration in paddyfield organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab（3.6） 〉 loach（3.3） 〉 carp（2.1）. BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their log KOWvalues was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern.
基金the National Basic Research Program of China(2003CB415002)the National Natural Science Foundation of China(No.20377022) the Guangxi Natural Science Fund(No.0236063)for their financial supports.
文摘Using the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures, the relative retention time （RRT） of polybrominated diphenyl ethers （PBDEs） were predicted. A four-variable regression model （M30） with the correlation coefficient of 0.9816 and the root mean square errors of 0.061 was developed using a training set including 30 PBDEs. The correlation coefficient of 0.9841 and the root mean square errors of 0.054 between the values of RRT predicted by M30 and the RRT observed for 16 external PBDEs show a good predictive potential of M30. The descriptors included in the M30 represent four interactions between four pairs of atom types, i.e., atom -C= and -C=, -C= and 〉C=, 〉C= and 〉C=, -C= and -Br.
基金supported by Fondecyt No. 1080294 and Fondecyt 1110719 (R Barra)
文摘This pilot study documented the occurrence and levels of brominated flame retardants in the tissues of farmed and wild salmon in southern Chile.Samples of Coho salmon and rainbow trout were obtained from fish farms,rivers and lakes in the Patagonia in Aysen Region,Chile.The samples were analyzed by Gas Chromatography Negative Chemical Ionization Mass Spectrometry for the different polybrominated diphenyl ether（PBDE） congeners.Contaminants were observed in all the samples,and the congeners BDE 17,28,47 and 66 were observed in all both farmed and wild samples.The concentrations were higher in the farmed Coho salmon,presenting significant differences with wild salmon.The levels reached 182 pg/g wet weight（ww） vs.120 ww.In the case of the rainbow trout,the concentrations were lower,although the congener profile was quite similar.The levels reached an average of 100 pg/g ww in the farmed fish versus 110 pg/g ww in wild fish,and no significant difference was observed between the species.In both species,the congener with the highest concentration was BDE 47.Based on this information,the BDE ？ow was estimated for commerce,which is a form of pollutant transport not usually considered in POP pollution studies.A preliminary estimation indicated that the quantity of PBDEs mobilized by commerce was in the order of kg,and in the case of Chile might reach almost 1 kg.
基金This work was supported by the National Natural Science Foundation of China(Nos.42077114 and 41771346)the Local Innovation and Entrepreneurship Team Project of Guangdong Special Support Program(No.2019BT02L218)Zhaoqing University Innovation Research Team Funding Project.
文摘Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils.The key to the development of leaching technology is selective removal of targeted pollutants in soil washing effluent and recycling of surfactant solutions.In this study,a molecular imprinting technique was applied to selectively sorb polybrominated diphenyl ethers(PBDEs)in soil washing effluent.The novel molecular imprinted polymers(MIPs)using different template molecules were synthesized by precipitation polymerization.Adsorption behaviors andmechanisms ofMIPs were studied through experiments and theoretical calculations.The results show that 4-bromo-4'-hydroxybiphenyl and toluene can be effective imprinting molecule for MIPs synthesis.The maximal adsorption capacity of selected dummy molecular imprinted polymer(D1-MIP)was 1032.36μmol/g,and that of part molecular imprinted polymer(P-MIP)was 981.13μmol/g.Their imprinting factors in 5 PBDEs adsorption ranged from 2.13 to 5.88,the recovery percentage of Triton X-100 can reach 99.09%,confirming the feasibility of reusing surfactant.Various PBDEs could be removed by MIPs,and Quantitative Structure Property Relationship analysis revealed that PBDEs’molecular volume,planarity,polarity,and hydrophobicity have major influences on their adsorption performance.DFT calculation revealed that Van derWaals force and hydrogen bonding played important roles during selective adsorption.These results can provide effective theoretical guidance for surfactant enhanced soil elution in practical engineering applications.
