Number Of Bromine Atoms Research Articles

Uptake and translocation of brominated flame retardants in tomato plants (Solanum lycopersicum L.): Results from a standard soil-based biotest

The uptake and translocation of four polybrominated diphenyl ethers (PBDEs) and four novel brominated flame retardants (NBFRs) in tomato plants (Solanum lycopersicum L.) were investigated via the RHIZOtest, a standard soil-based biotest, optimized for organic compounds. Tomato plants were exposed to soil samples spiked with 0 (i.e. control), 5.00 or 50.00 ng g−1dw of each compound. Compared of those of the control, exposure to increasing spiking concentrations resulted in average reductions of 13% and 26% (w/w) in tomato plant biomass. Higher concentrations of NBFRs were analyzed both in roots, ranging from 0.23 to 8.01 ng g−1dw for PBDEs and from 1.25 to 18.51 ng g−1dw for NBFRs, and in shoots, ranging from 0.09 to 5.58 ng g−1dw and from 0.47 to 7.78 ng g−1dw for PBDEs and NBFRs, respectively. This corresponded to an average soil uptake of 5% for PBDEs and 9% for NBFRs at the lower soil-spiking level, and 3% for PBDEs and 6% for NBFRs at the higher soil spiking level. Consequently, among both initial spiking levels, the soil-root concentration factor (RCF) values were lower on average for PBDEs (0.13 ± 0.05 g dw soil g−1dw roots) than for NBFRs (0.33 ± 0.16 g dw soil g−1dw roots). Conversely, nondifferent values of the root-shoot transfer factor (TF) were calculated for both PBDEs (0.54 ± 0.13 g dw roots g−1dw shoots) and NBFRs (0.49 ± 0.24 g dw roots g−1dw shoots). The differences and similarities reported in the RCF and TF between and within the two groups of compounds can be explained by their properties. The calculated RCF and TF values of the PBDEs exhibited a decreasing trend as the number of bromine atoms increased. Additionally, a robust negative linear correlation was observed between RCF values and the respective logKow values for the PBDEs, at both soil-spiking levels. The root uptake of NBFRs exhibited a negative correlation with their hydrophobicity; however, this was not observed in the context of root-to-shoot transfer. The presence of a second aromatic ring appears to be the key factor influencing the observed variations in NBFRs, with biphenyl NBFRs (BTBPE and DBDPE) characterized by lower uptake and reduced translocation potential than monophenyl PBEB and HBB. Understanding the transfer of these compounds to crops, especially near plastic recycling waste sites, is crucial for understanding the risks of their potential inclusion in the human food chain.

Halogen Bonding in Brominated BODIPY Crystals: a Crystallographic and Computational Study.

The study of halogen bonds (XBs) has been a subject of great interest in recent years due to its clear application in catalysis, liquid crystals, and crystal engineering. In this study we analyzed the intermolecular interactions, in particular halogen bonds in BODIPYs with increasing number of bromine atoms. The computational study included analyses through three different methods: the first approach of close contacts provided by Mercury, then the expanded approach of the electron density partition of the molecules in the crystals provided by the analysis of Hirshfeld surfaces, and finally, the approach of the Quantum Theory of Atoms in Molecules (QT-AIM) to characterize the non-covalent interactions through finding electron density critical points between atoms and between neighboring molecules. The use of different computational methods allowed to gain insight on the interactions directing the crystal packing as the number of bromine atoms increase in the BODIPY moiety. Monocoordinated and bifurcated halogen bonds involving halide/halide were found. The penta-brominated BODIPY showed four-center cyclic nodes where each node is linked via XBs. This kind of motifs can be useful in supramolecular chemistry and self-assembly.

Polyhalogenation-Facilitated Spirolactonization at the meta-Position of Phenols

A novel dearomative spirolactonization/polyhalogenation of phenols that employs hypervalent iodine PhICl2 (iodobenzene dichloride) as both an oxidant and chlorine source with an indispensable base, or only using NBS (N-bromosuccinimide) without any additives, is presented. Halide participations are a vital factor in the cascade reaction of 3'-hydroxy-[1,1'-biphenyl]-2-carboxylic acids with good selectivities and reactivities and induced the rapid constructions of multiple C-halogen bonds and directional C═O bonds in a one-step operation under mild conditions. In gaining a good understanding of the mechanism, the increase in number of bromine atoms was inferred rationally from the spirolactonization process, assisted by DFT calculations and high-resolution mass spectrometry. Mechanistic experiments suggest that the formation of a stable carbocation intermediate plays a great role in the migration of oxygen to spirolactonization.

Bromophenol Induced Multiple Stress Responses in Rice Plants: Impact of Doses and Congener Structures.

Bromophenols (BPs) have both natural and artificial sources in the environment and are frequently detected in plants. Herein, the ubiquitous 2,4,6-TriBP was hydroponically exposed to rice seedlings at two concentrations (0.2 and 2.0 mg/L) to characterize the dose-dependent abiotic stress responses of rice plants to BPs. The 2,4,6-TriBP induced oxidative damage to rice roots and subsequently inhibited plant transpiration and growth at the end of exposure in both concentrations. Moreover, the gene expression of OsUGT72B1 and the activity of glycosyltransferases of exposed rice roots were 2.36-to-4.41-fold and 1.23-to-1.72-fold higher than that of the blank controls after 24 h, following the formation of glycoconjugates in response to 2,4,6-TriBP exposure. It was notable that the glycosylation rates also showed a dose-effect relationship in rice roots. One and six glycoconjugates of 2,4,6-TriBP were detected in 0.2 and 2.0 mg/L exposure groups, respectively. Considering the detected species of glycoconjugates for four other types of BPs, the numbers of bromine atoms were found to dramatically affect their glycosylation process in rice plants. These results improve our fundamental understanding of the impact of congener structures and exposure concentrations of organic contaminants on the glycosylation process in response to phytotoxicity.

Determination of four trihalomethanes in ship ballast water by gas chromatography-negative chemical ionization-mass spectrometry

我国每年的船舶压载水排放量巨大,压载水中含有浮游生物、病原体及其幼虫或孢子等,若处理不当,会对排放水域的生态环境造成严重影响。排放压载水前常使用电解法对其进行处理,电解产生的次氯酸钠溶液,能有效杀灭残余的微生物。但电解后会产生副产物三卤甲烷(THMs),其对人体有一定的健康风险,建立船舶压载水中三卤甲烷的测定方法具有重要意义。该研究建立了采用气相色谱-负化学源质谱(GC-NCI-MS)测定船舶压载水中4种三卤甲烷(包括三氯甲烷、二氯一溴甲烷、一氯二溴甲烷、三溴甲烷)的分析方法。船舶压载水样品经过顶空进样技术处理后,通过DB-5MS UI毛细管色谱柱(30 m×0.25 mm×1.0 μm)分离,气相色谱-负化学源质谱仪测定,在选择离子扫描(SIM)模式下分析,采用外标法进行定量。4种三卤甲烷在0.2~50 μg/L范围内线性关系良好,相关系数(r)≥0.995,定量限(S/N=10)为0.1~0.2 μg/L,在0.2、0.5、2.0 μg/L 3个加标水平下,4种THMs的平均回收率为90.3%~106.8%,相对标准偏差(RSD)为1.4%~6.2%。该方法准确、稳定、可靠,可用于测定船舶压载水中4种THMs的含量。使用建立的测定方法对36个船舶压载水进行测定,三溴甲烷、二溴一氯甲烷、一溴二氯甲烷与三氯甲烷的检出率分别为83.3%、69.4%、22.2%和19.4%,检出值分别为34.25~221.5 μg/L、3.52~41.87 μg/L、1.52~8.56 μg/L和0.02~5.46 μg/L。

Successive Free-Radical C(sp 2 )–C(sp 2 ) Coupling Reactions to Form Graphene

Successive Free-Radical C(sp ² )–C(sp ² ) Coupling Reactions to Form Graphene

Toxicity of disinfection byproducts formed during the chlorination of sulfamethoxazole, norfloxacin, and 17β-estradiol in the presence of bromide.

Brominated disinfection byproducts (Br-DBPs) are formed during the disinfection process of water containing bromine ions, such as marine aquaculture water. Little attention has been paid to Br-DBPs with anthropogenic chemicals as precursors. This study summarized the sodium hypochlorite (NaClO) oxidation of three frequently used pharmaceuticals, including two antibiotics, norfloxacin (NOR) and sulfamethoxazole (SMX), and the growth hormone estrogen 17β-estradiol (E2). Transformations of the pharmaceuticals were found to be faster in marine aquaculture water than in distilled water. Several Br-DBPs and Cl-DBPs were identified for NOR, SMX, and E2. It was shown that the carboxyl group, piperazine ring, C3, and C8 atoms were the primary reaction sites on NOR. The aniline moiety and S-N bond were identified to be the reaction sites on SMX. The C2, C4, C9, and C16 atoms were the potential reaction centers on E2. Preliminary calculation by QSAR model indicated that the value of logKow significantly increased with an increase in the number of bromine atoms in the Br-DBPs. The results of the bioconcentration factors (BCF) analysis suggested that the bioaccumulation of Br-DBPs were greater than that chlorinated DBPs (Cl-DBPs) in distilled water.

Screening of brominated pyrolysis products of tetrabromobisphenol a by integrating controllable heating device with ambient mass spectrometry

Pyrolysis, an effective recycle strategy for resins or plastic containing tetrabromobisphenol A (TBBPA), often lead to formation of more toxic decomposition chemicals. Online collection coupled with off-line analysis for qualitative and quantitative analysis of the residue often induce information loss of these pyrolysis products. In this study, a temperature controllable thermal decomposition device coupled with an ambient mass spectrometry was directly employed for on-line monitoring of the pyrolysis process of TBBPA. Thermal products through debromination, methylation, methoxylation and β-scission have all been detected. Based on the mass spectra of TBBPA decomposition products, the number of bromine atoms and the m/z values, about 8 brominated decomposition products/intermediates have been identified. Temperature played the critical role for the pyrolysis processes. It was found that almost no TBBPA degraded at low temperature (100−150 °C), intensified decomposition happened at about 300 °C and small molecules formed in large quantities at > 450 °C.

Photodecomposition properties of brominated flame retardants (BFRs).

This study investigates the geometric and electronic properties of selected BFRs in their ground (S0) and first singlet excited (S1) states deploying methods of the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). We estimate the effect of the S0→ S1 transition on the elongations of the C-Br bond, identify the frontier molecular orbitals involved in the excitation process and compute partial atomic charges for the most photoreactive bromine atoms. The bromine atom attached to an ortho position in HBB (with regard to C-C bond; 2,2',4,4',6,6'-hexabromobiphenyl), TBBA (with respect to the hydroxyl group; 2,2',6,6'-tetrabromobisphenol A), HBDE and BTBPE (in reference to C-O linkage; 2,2',4,4',6,6'-hexabromodiphenylether and 1,2-bis(2,4,6-tribromophenoxy)ethane, respectively) bears the highest positive atomic charge. This suggests that, these positions undergo reductive debromination reactions to produce lower brominated molecules. Debromination reactions ensue primarily in the aromatic compounds substituted with the highest number of bromine atoms owing to the largest stretching of the C-Br bond in the first excited state. The analysis of the frontier molecular orbitals indicates that, excitations of BFRs proceed via π→π*, or π→σ* or n→σ* electronic transitions. The orbital analysis reveals that, the HOMO-LUMO energy gap (EH-L) for all investigated bromine-substituted aromatic molecules falls lower (1.85-4.91eV) than for their non-brominated analogues (3.39-8.07eV), in both aqueous and gaseous media. The excitation energies correlate with the EH-L values. The excitation energies and EH-L values display a linear negative correlation with the number of bromine atoms attached to the molecule. Spectral analysis of the gaseous-phase systems reveals that, the highly brominated aromatics endure lower excitation energies and exhibit red shifts of their absorption bands in comparison to their lower brominated congeners. We attained a satisfactory agreement between the experimentally measured absorption peak (λmax) and the theoretically predicted oscillator strength (λmax) for the UV-Vis spectra. This study further confirms that, halogenated aromatics only absorb light in the UV spectral region and that effective photodegradation of these pollutants requires the presence of photocatalysts.

A density functional theory/time-dependent density functional theory study of the structure-related photochemical properties of hydroxylated polybrominated diphenyl ethers and methoxylated polybrominated diphenyl ethers and metal ion effects.

Asthe derivatives and structural analogs of polybrominated diphenyl ethers (PBDEs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) have attracted increasing concern. However, knowledge of the photochemical behaviors of OH-PBDEs and MeO-PBDEs in water is limited. Here, we used density functional theory and time-dependent density functional theory to examine the structure-related photochemical properties of OH-PBDEs and MeO-PBDEs in water and the effects of metal ions as environmental factors. Eight 6-OH-PBDEs with 1-8 bromine substituents and eight 6-MeO-PBDEs with 1-8 bromine substituents were selected for this study. The optimized geometries of the selected congeners and their complexes with metals in the lowest excited triplet state (T1) showed that one C-Br bond moderately or significantly elongated. The elongated C-Br bond in the T1 state was shown in the ortho-position for the 6-OH-PBDE congeners and the ortho-position or the meta-position for the 6-MeO-PBDE congeners. For the selected congeners, there were significant positive linear correlations between the number of bromine atoms (NBr) and the calculated average atomic charge of bromine and maximum electronic absorbance wavelength (λmax), and a negative linear correlation between the NBr and average bond dissociation energy of C-O bonds (BDEC-O). The photoreactivities of the 6-OH-PBDEs and 6-MeO-PBDEs increased with an increase in the bromination degree with or without metal ions. The calculated average atomic charge of bromine and BDEC-O of the complexes with Mg2+/Zn2+ was higher and lower than those of the corresponding monomers, respectively, indicating that the presence of Mg2+/Zn2+ increased the photoreactivity (debromination and dissociation of C-O bond) of the selected 6-OH-PBDEs and 6-MeO-PBDEs. The effects of the coordination of Mg2+/Zn2+ may be overestimated due to their missing explicit solvation shell. These results provide vital insight into the photochemical properties of OH-PBDEs and MeO-PBDEs in water.

Changes in the activities of antioxidant enzymes and reduced glutathione level in human erythrocytes exposed to selected brominated flame retardants

Currently, more and more concerns are related to oxidative stress appearing in cells as a result of xenobiotics action. It has been found that selected brominated flame retardants (BFRs) can cause reactive oxygen species (ROS) induction at environmental concentrations. Excessive ROS induction can contribute to the redox imbalance in the cell.Therefore, the aim of our work was to evaluate the effect of selected BFRs on the activity of antioxidant enzymes, i.e. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the level of reduced glutathione (GSH) in human erythrocytes. Erythrocytes were incubated with tetrabromobisphenol A (TBBPA), tetrabromobisphenol S (TBBPS), 2,4-dibromophenol (2,4-DBP), 2,4,6-tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) in the concentration ranging from 1 to 100 μg/ml. This study has shown that the BFRs studied disturbed redox balance in human erythrocytes. TBBPA caused more significant decrease in antioxidant enzymes activities than other compounds examined. Among bromophenols studied, 2,4-DBP most strongly affected antioxidant system, which indicated that the number of bromine atoms in the molecule did not significantly affect the pro-oxidative properties of the BFRs examined.

Computational investigation of the atmospheric oxidation reactions of polybrominated dibenzo-p-dioxins initiated by OH radicals

Density functional theory (DFT) method was used to study OH-initiated atmospheric oxidative reactions of some polybrominated dibenzo-p-dioxins (PBDDs). B3LYP functional and 6–311++G (2df,p) basis set were applied to optimize molecular structures of all stationary points involved in the investigated reactions. The rate constants for key elementary reactions were estimated by means of transition state theory. The computational results demonstrate that all addition reactions of PBDDs with OH radicals can occur spontaneously at standard conditions, however, the OH addition reactions are very slow due to low atmospheric concentration of OH radicals. Addition reactions occurring at γ-C position dominate in OH addition of all PBDDs. With the number of bromine atoms substituting at α-sites increases, the overall rate coefficients of OH addition decrease. The succeeding addition reactions of PBDD-OH adducts with O2 take place hardly both thermodynamically and kinetically. Abstraction reaction of H atoms by O2 is a governing route for PBDD-α(β)-adducts without bromine atoms at the same site, while the fused-ring CO bond fission is a main reaction channel for PBDD-γ-adducts, which will produce substituted phenoxy radicals.

A Novel and Simple Method for the Prediction of Corrosion Inhibition Efficiency without Using Complex Computer Codes

A novel method for prediction of the inhibition efficiency of pyridine and imidazole derivatives is proposed. It does not require computer codes and unusual descriptors. It is based on the number of bromine atoms, the sum of the number of carbon and nitrogen atoms, and different structural factors. For 30 inhibitors, the root means squared (RMS) deviation of the new method is 4.00, which is lower than the best available method, i.e. 19.22. High reliability of new model is also tested for further 17 derivatives of pyridine and imidazole, where the value of RMS deviation is 6.17 for these data.

Evaluation of the effect of brominated flame retardants on hemoglobin oxidation and hemolysis in human erythrocytes

Brominated flame retardants (BFRs) are widely used in many everyday products. Numerous studies have shown that BFRs can be released into the environment. Environmental pollution with these compounds raises concerns about their potentially adverse health effects. The aim of this study was to evaluate the effect of tetrabromobisphenol A (TBBPA), tetrabromobisphenol S (TBBPS), 2,4-dibromophenol (2,4-DBP), 2,4,6- tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) on hemolysis induction and hemoglobin oxidation in human erythrocytes. The erythrocytes were incubated with selected BFRs in a wide concentrations ranging from 0.01 to 100 μg/ml for 24 h, 48 h and 72 h. All compounds studied, exhibited hemolytic potential and induced methemoglobin formation. Hemolytic and oxidative potential of BFRs increased along with the increasing concentrations of the compounds studied and elongation of the incubation time. Our study showed that both the number of aromatic rings and the number of bromine atoms in the molecule of the compounds examined influence hemoglobin oxidation and damage to the cellular membrane. Furthermore, we may conclude that 2,4-DBP is potentially most toxic compound because it causes statistically significant changes at the lowest concentration, while the highest toxicity at the highest concentrations was noted for TBBPA.

Size distribution of particle-associated polybrominated diphenyl ethers (PBDEs) and their implications for health

Abstract. In order to better understand the size distribution of particle-associated PBDEs and their deposition pattern in the human respiratory tract, we carried out a 1-year campaign during 2012–2013 for the measurement of size-resolved particles at the urban site of Shanghai. The results showed that particulate PBDEs exhibited a bimodal distribution with a mode peak in the accumulation particle size range and the second mode peak in the coarse particle size ranges. As the number of bromine atoms in the molecule increases, accumulation-mode peak intensity increased while coarse-mode peak intensity decreased. This change was consistent with the variation of PBDEs' subcooled vapor pressure. Absorption and adsorption processes dominated the distribution of PBDEs among the different size particles. The evaluated deposition flux of Σ13 PBDEs was 26.8 pg h−1, in which coarse particles contributed most PBDEs in head and tracheobronchial regions, while fine-mode particles contributed major PBDEs in the alveoli region. In association with the fact that fine particles can penetrate deeper into the respiratory system, fine-particle-bound highly brominated PBDEs can be inhaled more deeply into human lungs and cause a greater risk to human health.

Photodecomposition of bromophenols

Photodecomposition of bromophenols (BPs) represents a potent channel of debromination and elimination of these species in the environment. From this perspective, the present contribution reports geometrical parameters, electronic absorption spectra and excited states of the complete series of BPs in their ground state (S0), as well as their first singlet exited state (S1). We calculate excitation energies for S0 → S1 transition within the framework of the time-dependent density functional theory (TDDFT). We estimate and discuss charges on bromine atoms and HOMO-LUMO energy gaps (EH−L) as molecular descriptors for the photoreactivity of BPs and photo-induced debromination mechanism of BPs. Spectral patterns reveal that, as the degree of bromination increases, peaks of absorption spectra red-shift toward wavelengths near 300 nm, for the pentabrominated phenol. Based on the analysis of optimised geometries and Hirshfeld's atomic charges, photodebromination of BPs commences via the loss of an ortho Br atom. The excitation energies decrease linearly with increasing number of bromine atoms. This indicates that, higher brominated congeners of BPs photodecompose more readily than lower brominated congeners.

Biosorption and degradation of decabromodiphenyl ether by Brevibacillus brevis and the influence of decabromodiphenyl ether on cellular metabolic responses.

There is global concern about the effects of decabromodiphenyl ether (BDE209) on environmental and public health. The molecular properties, biosorption, degradation, accumulation, and cellular metabolic effects of BDE209 were investigated in this study to identify the mechanisms involved in the aerobic biodegradation of BDE209. BDE209 is initially absorbed by wall teichoic acid and N-acetylglucosamine side chains in peptidoglycan, and then, BDE209 is transported and debrominated through three pathways, giving tri-, hepta-, octa-, and nona-bromodiphenyl ethers. The C-C bond energies decrease as the number of bromine atoms on the diphenyl decreases. Polybrominated diphenyl ethers (PBDEs) inhibit protein expression or accelerate protein degradation and increase membrane permeability and the release of Cl(-), Na(+), NH4 (+), arabinose, proteins, acetic acid, and oxalic acid. However, PBDEs increase the amounts of K(+), Mg(2+), PO4 (3-), SO4 (2-), and NO3 (-) assimilated. The biosorption, degradation, accumulation, and removal efficiencies when Brevibacillus brevis (1 g L(-1)) was exposed to BDE209 (0.5 mg L(-1)) for 7 days were 7.4, 69.5, 16.3, and 94.6 %, respectively.

CP-MLR Directed QSAR Rationales for the 1-aryl Sulfonyl Tryptamines as 5-HT6 Receptor Ligands

A QSAR study has been carried out to rationalize the 5-HT6 receptor binding affinities of the 1-aryl sulfonyl tryptamine derivatives using Dragon descriptors. A higher value of molecular symmetry and topology accounting Randic shape index descriptor PW4 (path/walk 4) would be favorable to improve the binding affinity. Presence of more number of bromine atoms (descriptor nBR) and presence of such structural fragment in which a hydrogen atom attached to sp3 hybridized carbon with no hetero atom rather than one hetero atom attached to next carbon atom (descriptors H-046 and H-052) will be supportive to the activity. The prevalence of atomic properties to explain the binding affinity is evident from the associations of polarizability to the path length 7 of Moran autocorrelation (MATS7p), masses to eigenvalues n.2 and 7 of Burden m atrix (BELm2 and BEHm7), Sanderson electronegativity to highest eigenvalue n.2 Burden matrix (BEHe2) and van der Waals volume to path length 8 of Geary autocorrelation (GATS8v) and charge content in terms of topological and mean topological charge indices (GGI3 and JGI2). The dominance of the information content of the descriptors, emerged in CP-MLR models, has also confirmed by the PLS analysis. The derived QSAR models and descriptors shared in these models revealed that the substituents of tryptamine moiety have sufficient scope for further modification.

Oxidative stress in human erythrocytes treated with bromfenvinphos and its impurities

Bromfenvinphos (BFVF) is an organophosphorus (OP) pesticide which was widely used in agriculture and veterinary practice. During synthesis of this insecticide five main impurities are formed: dihydro-bromfenvinphos, dibromo-bromfenvinphos, 2,4-dichlorophenacyl bromide, 2,4-dichlorophenacylidene bromide and 2,4-dichlorophenacylidyne bromide, which can be present in technical grade bromfenvinphos in amounts from 0.1 to 4%.The aim of this study was to examine the influence of bromfenvinphos and its manufacturing impurities on parameters of oxidative stress, the activity of antioxidative enzymes and the level of reduced glutathione. Human erythrocytes were incubated with bromfenvinphos and its impurities in the concentrations range from 0.5 to 500 µM for 1 h.This study indicated that 2,4-dichlorophenacyl derivatives more strongly oxidized analyzed parameters in human erythrocytes than bromfenvinphos. Investigated compounds caused an increase in lipid peroxidation and oxidation of fluorescent probe DCFH2 – the strongest pro-oxidative changes were provoked by 2,4-dichlorophenacyl bromide. None of the compounds studied in the concentrations from 0.5 to 500 µM changed the activity of SOD and only 2,4-dichlorophenacyl decreased activity of CAT. The level of GSH was only altered by 2,4-dichlorophenacyl derivatives. It was observed that increasing number of bromine atoms in the side chain of those derivatives was associated with decreased GSH level.

Polybrominated diphenyl ethers in residential and agricultural soils from an electronic waste polluted region in South China: Distribution, compositional profile, and sources

A detailed investigation was conducted to understand the concentration, distribution, profile and possible source of polybrominated diphenyl ethers (PBDEs) in residential and agricultural soils from Guiyu, Shantou, China, one of the largest electronic waste (e-waste) recycling and dismantling areas in the world. Ten PBDEs were analyzed in 46 surface soil samples in terms of individual and total concentrations, together with soil organic matter concentrations. Much higher concentrations of the total PBDEs were predicted in the residential areas (more than 2000ngg−1), exhibiting a clear urban source, while in the agricultural areas, concentrations were lower than 1500ngg−1. PBDE-209 was the most dominant congener among the study sites, indicating the prevalence of commercial deca-PBDE. However signature congeners from commercial octa-PBDE were also found. The total PBDE concentrations were significantly correlated with each individual PBDE. Principal component analysis indicated that PBDEs were mainly distributed in three groups according to the number of bromine atoms on the phenyl rings, and potential source. This study showed that the informal e-waste recycling has already introduced PBDEs into surrounding areas as pollutant which thus warrants an urgent investigation into the transport of PBDEs in the soil-plant system of agricultural areas.