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Chen G, Deng X, Wang J. Pollution level, spatial distribution, and congener fractionation characteristics of low-brominated polybrominated diphenyl ethers (PBDEs) in sediments around Chaohu Lake, China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:631. [PMID: 35920914 DOI: 10.1007/s10661-022-10246-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
As new persistent organic compounds, polybrominated diphenyl ethers (PBDEs) have aroused important concern because of their potential bioaccumulation and possible ecological and health risk. To examine the sources and temporal variation of PBDEs in Chaohu Lake in eastern China, the surface sediments from Nanfei River (NFR) and core sediments from four estuaries were measured. It showed that low-brominated congeners were dominant, from MonoBDEs to HeptaBDEs (referred to as Σ39PBDE). Concentrations of ∑39PBDE and the ratios of (BDE-47 + BDE-99 + BDE-100)/(BDE-153 + BDE-154) were much greater in surface sediments than in core sediments. The highest concentration was observed in a site close to the outfall of a municipal sewage treatment plant (MSTP), and the ratio was significantly correlated with ∑39PBDE. These results suggested that PentaBDE and OctaBDE commercial mixtures were widely used around Chaohu Lake and the effluent of municipal sewage was a dominant source of PBDEs to surface sediment. Compared to data from other freshwater systems around the world, the concentrations of BDE-47 and BDE-99 in this study were in the middle of the range of global data, but BDE-183 concentrations were at the high end of the range. Due to restrictions on the usage of PentanBDE and OctaBDE commercial mixtures, reductions of PBDE levels from subsurface to superficial layer were observed in all estuaries. Elevated contribution by MonoBDEs to ∑39PBDE in the estuary of the only outflow river suggests significant congener fractionation. TriBDEs, TetraBDEs, and HexaBDEs appeared to pose low risks in all surface sediments, but moderate to high risks may be expected for PentaBDEs. Overall, the results would contribute to a better understanding of the sources and environmental fate of PBDEs in the studied eutrophicated lake.
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Affiliation(s)
- Guangzhou Chen
- Anhui Key Laboratory of Environmental Pollution Control and Waste Resource Utilization, Anhui Jianzhu University, Hefei, 230601, China.
- Anhui Key Laboratory of Water Pollution Control and Waste Water Recycling, Anhui Jianzhu University, Hefei, 230601, China.
- Anhui Research Academy of Ecological Civilization, Anhui JianZhu University, Hefei, 230601, China.
| | - Xinyue Deng
- Anhui Key Laboratory of Environmental Pollution Control and Waste Resource Utilization, Anhui Jianzhu University, Hefei, 230601, China
- Anhui Key Laboratory of Water Pollution Control and Waste Water Recycling, Anhui Jianzhu University, Hefei, 230601, China
| | - Jizhong Wang
- LID, Guangzhou GRG Metrology & Test (Hefei) CO, Hefei, 230088, China.
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Ren Z, Zeng Y, Luo X, Huang C, Tian Y, Gao S, Mai B. Observable carbon isotope fractionation in the photodegradation of polybrominated diphenyl ethers by simulated sunlight. CHEMOSPHERE 2021; 266:128950. [PMID: 33218726 DOI: 10.1016/j.chemosphere.2020.128950] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
In the present study, carbon isotope effects were investigated during the photodegradation of polybrominated diphenyl ethers (PBDEs) by compound-specific stable isotope analysis (CSIA). Five PBDE congeners (BDE 85, 99, 100, 153 and 154) in n-hexane were individually exposed to simulated sunlight for as long as 15 h, except for BDE 100 (24 h). Consecutive debromination of PBDE by photolysis in n-hexane was confirmed by the clear 13C enrichment of mother congeners and successive depletion of δ13C values for the photodegradation products with decreasing degree of bromination, which can be attributed to mass-dependent isotope fractionation. The observed variation in the isotope fractionation trends for the para-debrominated products might be linked to the different photocatalytic activities of the PBDE congeners. Higher fractionation was observed for penta-BDEs (εc=-2.2 ± 0.45‰ and -2.3 ± 0.26‰ for BDE 85 and BDE 99, respectively) compared to that for hexa-BDEs (εc=-1.7 ± 0.41‰, and -1.3 ± 0.12‰ for BDE 153 and BDE 154, respectively). Normal isotope effects (AKIE > 1) observed in our study supports the utility of CSIA for the evaluation of the photodegradation of PBDEs.
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Affiliation(s)
- Zihe Ren
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Yanhong Zeng
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China.
| | - Xiaojun Luo
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China
| | - Chenchen Huang
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Yankuan Tian
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China
| | - Shutao Gao
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China
| | - Bixian Mai
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People's Republic of China
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Yuan X, Wang Y, Tang L, Zhou H, Han N, Zhu H, Uchimiya M. Spatial distribution, source analysis, and ecological risk assessment of PBDEs in river sediment around Taihu Lake, China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:309. [PMID: 32328811 DOI: 10.1007/s10661-020-08286-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/13/2020] [Indexed: 06/11/2023]
Abstract
The distribution and composition of organic pollutants in sediment are affected by the source and regional environment. To understand the characteristics and risk of polybrominated diphenyl ethers (PBDEs) in the area around Taihu Lake, composite sediment samples (n = 41) were collected in rivers around Taihu Lake to explore the level, spatial distribution, and source of PBDEs. The results showed that the most abundant BDE congener in river sediment was BDE209, followed by BDE99 and BDE47, with median values of 48.7, 2.17, and 1.52 ng g-1, respectively. Concentrations of PBDEs in sediments from northern rivers were significantly higher than those from other areas, but the overall risk was at a moderate-lower level compared with research results in other references. Results of principle component analysis (PCA) and source characteristics analysis revealed that most of PBDEs in river sediments around Taihu Lake were mixture of multiple sources, which mainly originated from atmospheric deposition, industrial wastewater, and municipal sewage. TOC showed good correlations with most PBDEs, which implied that PBDE components were influenced by sediment organic matter. Meanwhile, the risk of PBDEs in river sediments in this study area is a moderate-lower level.
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Affiliation(s)
- Xuyin Yuan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, Hohai University, Nanjing, 210098, China.
- College of Environment, Hohai University, Nanjing, 210098, China.
| | - Yimin Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, Hohai University, Nanjing, 210098, China
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Li Tang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, Hohai University, Nanjing, 210098, China
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Huihua Zhou
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Nian Han
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Hai Zhu
- College of Environment, Hohai University, Nanjing, 210098, China
| | - Minori Uchimiya
- USDA-ARS Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA, 70124, USA
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Wang S, Wang S, Shah S, Li L, Fang H, Hao C. 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. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:9297-9306. [PMID: 31916157 DOI: 10.1007/s11356-019-07538-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 12/25/2019] [Indexed: 06/10/2023]
Abstract
As the 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.
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Affiliation(s)
- Se Wang
- School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
| | - Shuwen Wang
- School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing, 210044, China
| | - Shaheen Shah
- Department of Chemistry, Karakorum International University, Gilgit, Gilgit-Balitstan, 15100, Pakistan
| | - Longyan Li
- School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing, 210044, China
| | - Hao Fang
- School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing, 210044, China
| | - Ce Hao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, Liaoning, China
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5
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Zhou S, Pan X, Tang Q, Zhu H, Zhou J, Zhao L, Guo J, Wang Z, Liu W, Li A. Photochemical degradation of polyhalogenated carbazoles in hexane by sunlight. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 671:622-631. [PMID: 30939315 DOI: 10.1016/j.scitotenv.2019.03.325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 05/28/2023]
Abstract
Polyhalogenated carbazoles (PHCZs) are a class of halogenated dibenzopyrrole, which have been increasingly detected in the environment and found to be bioaccumulative and potentially toxic. However, their environmental transformation potential is largely unknown. In this study, UV absorption spectra of carbazole (CZ) and 10 PHCZs were obtained with wavelength range 290-400 nm, and three peaks were identified in most cases with the highest occurring around 300 nm. Hexane solutions of CZ, 10 individual PHCZs, and a sediment extract containing nine other PHCZs were separately irradiated under natural sunlight in order to investigate their photodegradation kinetics and pathways. The pseudo-first-order reaction rate constants (k) of these PHCZs varied from 0.183 h-1 to 2.394 h-1, and increased exponentially with increasing numbers of chlorines and bromines in PHCZ molecules. Contribution to ln k from each bromine atom is more than doubling of that from each chlorine atom. Stepwise reduction debromination was confirmed to be one of the photodegradation mechanisms for both brominated and mixed halogenated (containing both bromine and chlorine) carbazoles. Only sporadic dechlorinated products were found during the photolysis of chlorinated carbazoles. By adopting a simplified kinetic approach, we estimated that dehalogenation contributed approximately 20% to 51% of the total loss of the parent PHCZs.
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Affiliation(s)
- Shanshan Zhou
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; School of Public Health, University of Illinois at Chicago, Chicago IL60612, United States.
| | - Xiaoxue Pan
- School of Public Health, University of Illinois at Chicago, Chicago IL60612, United States; School of Environment, Nanjing University, Nanjing 210093, China
| | - Qiaozhi Tang
- School of Public Health, University of Illinois at Chicago, Chicago IL60612, United States; College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hongbin Zhu
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiayi Zhou
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Lu Zhao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiehong Guo
- School of Public Health, University of Illinois at Chicago, Chicago IL60612, United States
| | - Zunyao Wang
- School of Environment, Nanjing University, Nanjing 210093, China
| | - Weiping Liu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - An Li
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; School of Public Health, University of Illinois at Chicago, Chicago IL60612, United States; College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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6
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Yang J, Huang D, Zhang L, Xue W, Wei X, Qin J, Ou S, Wang J, Peng X, Zhang Z, Zou Y. Multiple-life-stage probabilistic risk assessment for the exposure of Chinese population to PBDEs and risk managements. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 643:1178-1190. [PMID: 30189534 DOI: 10.1016/j.scitotenv.2018.06.200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/13/2018] [Accepted: 06/16/2018] [Indexed: 06/08/2023]
Abstract
Studies assessing body burden of polybrominated diphenyl ethers (PBDEs) exposure have been conducted in the United States and Europe. However, the long-term assessment that is associated with multimedia exposure of PBDEs for the Chinese population is not available. The current study estimated the health risks using large PBDEs data to quantify the contributions of various media from different regions and distinguished the most vulnerable periods in life. We summarized media-specific (soil, dust, outdoor and indoor air, human milk and food) concentration of PBDEs in China from 2005 to 2016. Probabilistic risk assessment was adopted to estimate the health risks of infants, toddlers, children, teenagers and adults through ingestion, inhalation and dermal absorption. Monte Carlo simulation and sensitivity analysis were performed to quantify risk estimates uncertainties. E-waste areas had the highest PBDEs concentration, which was at least an order of magnitude higher than in other areas. BDE209 was the primary congener, accounting for 38-99% of the estimated daily intake. The dominant exposure pathway for infants was dietary intake through human milk, whereas dust ingestion was a higher contributing factor for toddlers, children, teenagers and adults. The 95th percentile of hazard index for infants and toddlers from e-waste areas of Guangdong and Zhejiang provinces exceeded one. Our estimates also suggested that infants may have the highest body burdens of PBDEs compared to other age groups. Sensitivity analyses indicated that PBDEs concentrations and ingestion rates contributed to major variances in the risk model. In this study, e-waste was found as a significant source of PBDEs, and PBDEs-containing e-waste are likely to be a threat to human health especially during early period of life. Risk strategies for better managing environmental PBDEs-exposure and human health are needed, due to the high intake of PBDEs and their persistence in the environment.
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Affiliation(s)
- Jie Yang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Daizheng Huang
- Department of Biomedical Engineering, School of Preclinical Medicine, Guangxi Medical University, Nanning 530021, China
| | - Li'e Zhang
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - William Xue
- North Carolina University, 2101 Hillsborough Street, Raleigh, NC 27695, United States
| | - Xiao Wei
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Jian Qin
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Songfeng Ou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Jian Wang
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Xiaowu Peng
- Center for Environmental Health Research, South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou, Guangdong, China
| | - Zhiyong Zhang
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, China; School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Yunfeng Zou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning 530021, China.
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Yang X, Lu G, Huang K, Wang R, Duan X, Yang C, Yin H, Dang Z. Synergistic solubilization of low-brominated diphenyl ether mixtures in nonionic surfactant micelles. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.07.108] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Santos MSF, Alves A, Madeira LM. Chemical and photochemical degradation of polybrominated diphenyl ethers in liquid systems - A review. WATER RESEARCH 2016; 88:39-59. [PMID: 26465809 DOI: 10.1016/j.watres.2015.09.044] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 07/24/2015] [Accepted: 09/27/2015] [Indexed: 06/05/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants which have received a great deal of attention due to their persistence, potential to bioaccumulate and possible toxic effects. PBDEs have been globally detected in humans, wildlife and environment, highlighting the urgency of looking for effective removal technologies to mitigate their spread and accumulation in the environment. Among all environmental compartments, the water has raised particular attention. This paper aims to provide information about the suitability of the main degradation processes investigated to date (photolysis, zerovalent iron and TiO2 photocatalysis) for the degradation of PBDEs in water matrices. The most relevant criteria behind the design of a system for such purpose are discussed in detail for each individual process. The comparative analysis suggests that the oxidative degradation by TiO2 is the most appropriated technology to treat waters contaminated with PBDEs because higher debromination and mineralization degrees are achieved, preventing the formation/accumulation of lower brominated PBDE congeners and promoting the cracking of aromatic cores.
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Affiliation(s)
- Mónica S F Santos
- LEPABE - Laboratory for Process, Environmental, Biotechnology and Energy Engineering, Faculty of Engineering, University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.
| | - Arminda Alves
- LEPABE - Laboratory for Process, Environmental, Biotechnology and Energy Engineering, Faculty of Engineering, University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal
| | - Luis M Madeira
- LEPABE - Laboratory for Process, Environmental, Biotechnology and Energy Engineering, Faculty of Engineering, University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal.
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Vetter W, Bendig P, Blumenstein M, Hägele F, Behnisch PA, Brouwer A. Formation of polybrominated dibenzofurans (PBDFs) after heating of a salmon sample spiked with decabromodiphenyl ether (BDE-209). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:14530-14536. [PMID: 25043594 DOI: 10.1007/s11356-014-3267-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/26/2014] [Indexed: 06/03/2023]
Abstract
Fish is a major source for the intake of polybrominated diphenyl ethers (PBDEs). However, fish is scarcely consumed without being cooked, and previous studies showed that the heating of salmon fillet contaminated with BDE-209 for longer periods of time was accompanied with the partial transformation of this brominated flame retardant. In this study, we heated salmon fillet spiked with BDE-209 and verified that this process was linked with the formation of polybrominated dibenzofurans (PBDFs) in the fish. Each minute of heating 1 g salmon fillet spiked with 200 ng BDE-209 generated about 0.5 ‰ PBDFs relative to the initial amount of the pre-dioxin BDE-209. This result of the chemical analysis by gas chromatography with mass spectrometry (GC/MS) was verified by means of an effect-directed bio-assay (DR CALUX). While unheated salmon with BDE-209 and heated salmon without BDE-209 were tested nontoxic, the bioanalytical response of fish linearly increased upon heating. We also found that PBDF formation did neither occur with BDE-47 nor when BDE-209 was heated in edible oil instead of salmon fillet. Due to the formation of PBDFs in this process, the consumption of heated, BDE-209 contaminated fish may add to the uptake of dioxin-like compounds with our diet.
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Affiliation(s)
- Walter Vetter
- Institute of Food Chemistry, University of Hohenheim, 70593, Stuttgart, Germany.
| | - Paul Bendig
- Institute of Food Chemistry, University of Hohenheim, 70593, Stuttgart, Germany
| | - Marina Blumenstein
- Institute of Food Chemistry, University of Hohenheim, 70593, Stuttgart, Germany
| | - Florian Hägele
- Institute of Food Chemistry, University of Hohenheim, 70593, Stuttgart, Germany
| | - Peter A Behnisch
- BioDetection Systems BV (BDS), Science Park 406, 1098 XH, Amsterdam, The Netherlands
| | - Abraham Brouwer
- BioDetection Systems BV (BDS), Science Park 406, 1098 XH, Amsterdam, The Netherlands
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Photolysis of Low-Brominated Diphenyl Ethers and Their Reactive Oxygen Species-Related Reaction Mechanisms in an Aqueous System. PLoS One 2015; 10:e0135400. [PMID: 26274605 PMCID: PMC4537200 DOI: 10.1371/journal.pone.0135400] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 07/21/2015] [Indexed: 11/19/2022] Open
Abstract
To date, no report was concerned with participation of reactive oxygen species in waters during photolysis of low-brominated diphenyl ethers (LBDEs). Herein, we found that electron spin resonance (ESR) signals rapidly increased with increasing irradiation time in the solution of LBDEs and 4-oxo-TMP solutions. But this phenomenon did not occur in the presence of NaN3 (1O2 quencher) demonstrating generation of 1O2 in process of LBDEs photolysis. The indirect photolytic contribution rate for BDE-47 and BDE-28 was 18.8% and 17.3% via 1O2, and 4.9% and 6.6% via ·OH, respectively. Both D2O and NaN3 experiments proved that the indirect photolysis of LBDEs was primarily attributable to 1O2. The bimolecular reaction rate constants of 1O2 with BDE-47 and BDE-28 were 3.12 and 3.64 × 106 M-1 s-1, respectively. The rate constants for BDE-47 and BDE-28 (9.01 and 17.52 × 10−3 min-1), added to isopropyl alcohol, were very close to those (9.65 and 18.42 × 10−3 min-1) in water, proving the less indirect photolytic contribution of ·OH in water. This is the first comprehensive investigation examining the indirect photolysis of LBDEs in aqueous solution.
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Photochemical degradation of polybrominated diphenyl ethers in microreactor. RESEARCH ON CHEMICAL INTERMEDIATES 2015. [DOI: 10.1007/s11164-015-2033-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
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Sun Y, Yuan GL, Li J, Li JC, Wang GH. Polybrominated diphenyl ethers in surface soils near the Changwengluozha Glacier of Central Tibetan Plateau, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 511:399-406. [PMID: 25569575 DOI: 10.1016/j.scitotenv.2014.12.097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 12/13/2014] [Accepted: 12/29/2014] [Indexed: 06/04/2023]
Abstract
Forty-two congeners of polybrominated diphenyl ethers (PBDEs) were detected for each of 27 surface-soil samples collected at an area near the Changwengluozha Glacier in the Central Tibetan Plateau (CTP), a remote background area at altitude from 5080 to 5217 m. The total concentrations of BDEs in soils ranged from 15.3 to 248.0 ng/kg, which were found to be positively correlated with the clay contents in the soil. In addition to adsorption, the clay was found to serve as a catalyst for the debromination of PBDEs in soils. Three pieces of evidence confirmed that the clay was significantly correlated with the debrominating transformation from the higher brominated congeners to the less brominated congeners. The transforming rate was found to be increased 3.5% with a 10% increase in clays. Debromination is an important way for highly brominated congeners to transform into lighter brominated congeners that are more toxic. This study first provided the direct field evidences for clays contributing to the debromination of PBDEs, and elucidated the importance of it in PBDEs' environmental fate.
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Affiliation(s)
- Yong Sun
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Guo-Li Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
| | - Jun Li
- School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Jing-Chao Li
- School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Gen-Hou Wang
- School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
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Wang S, Hao C, Gao Z, Chen J, Qiu J. Theoretical investigations on direct photolysis mechanisms of polychlorinated diphenyl ethers. CHEMOSPHERE 2014; 111:7-12. [PMID: 24997893 DOI: 10.1016/j.chemosphere.2014.03.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 02/20/2014] [Accepted: 03/07/2014] [Indexed: 06/03/2023]
Abstract
Polychlorinated diphenyl ethers (PCDEs) are a focus of current environmental concern as a group of ubiquitous potential persistent organic pollutants. There are still significant gaps in our knowledge concerning the photolysis mechanisms of PCDEs. In this study, the direct photolysis mechanisms of PCDEs were investigated by density functional theory. The direct photolysis of PCDEs has three potential reaction pathways including photodechlorination, C-O bond photodissociation, and PCDFs formation. Taking a representative PCDE (i.e., CDE8) for example, we found that C-Cl bond dissociation is the rate-determining step for the photodechlorination. Chlorobenzene is predicted to be photoproduct of CDE8 through the photodissociation of the C-O bond. Furthermore, the calculated mean bond dissociation energies of both C-Cl and C-O bonds of 20 PCDEs decrease with the increased degree of chlorination. It is also found that the photoactivity of PCDEs increases with an increase of chlorination degree by evaluating the average charge of Cl atoms and mean bond dissociation energies of C-Cl and C-O bonds from reaction thermodynamics. Our findings provided a new insight into the mechanisms of direct photolysis of PCDEs, which may be useful in the future in utilizing quantum chemistry calculation in investigating the behavior and fate of organic pollutants in the environment.
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Affiliation(s)
- Se Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Ce Hao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China.
| | - Zhanxian Gao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jieshan Qiu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
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Wang JZ, Hou Y, Zhang J, Zhu J, Feng YL. Transformation of 2,2',4,4'-tetrabromodiphenyl ether under UV irradiation: potential sources of the secondary pollutants. JOURNAL OF HAZARDOUS MATERIALS 2013; 263 Pt 2:778-783. [PMID: 24225586 DOI: 10.1016/j.jhazmat.2013.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/30/2013] [Accepted: 10/03/2013] [Indexed: 06/02/2023]
Abstract
A commercial brominated flame retardant 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was used as the model chemical to investigate the degradation and transformation of polybrominated diphenyl ethers (PBDEs) in gas and liquid phases, respectively, under ultraviolet (UV) irradiation. The results showed that BDE-47 can be transformed to less-brominated BDE analogs. A total of six compounds that are less-brominated BDEs and two brominated phenols were observed as transformation products in the reaction mixtures. Different degradation rates of BDE-47 in n-nonane and in isooctane in the same chamber system were observed. Degradation rate of BDE-47 in n-nonane was faster than in isooctane. Under UV irradiation, the bromine on the ortho positions of the phenyl rings was lost first to form 2,4,4'-tribromodiphenyl ether (BDE-28), which then progressively lead to 4,4'-dibromodiphenyl ether (BDE-15) or 2,4'-dibromodiphenyl ether (BDE-8). An airborne transformation pathway has been proposed according to observed transformation products. The more volatile less-brominated BDEs from transformation of BDE-47 are easily evaporated into air to be a source of secondary pollutants in the environment.
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Affiliation(s)
- Ji-Zhong Wang
- Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, AL: 0800C, EHC, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0K9
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15
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Rotko G, Romańczyk PP, Kurek SS. Reductive debromination of decabromodiphenyl ether yields brominated dibenzofurans in a Pschorr-type cyclisation. Electrochem commun 2013. [DOI: 10.1016/j.elecom.2013.10.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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16
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Widespread occurrence of polyhalogenated compounds in fat from kitchen hoods. Anal Bioanal Chem 2013; 405:7485-96. [DOI: 10.1007/s00216-013-7194-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/14/2013] [Accepted: 06/28/2013] [Indexed: 10/26/2022]
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17
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Bendig P, Vetter W. UV-induced formation of bromophenols from polybrominated diphenyl ethers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:3665-3670. [PMID: 23472584 DOI: 10.1021/es304785f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bromophenols (BPs) are both man-made industrial compounds and naturally produced secondary metabolites of algae and sponges. This study explored the formation of BPs by UV irradiation of polybrominated diphenyl ethers (PBDEs). Simulated sunlight (10-80 min) and natural sunlight irradiations (5 days) of BDE-153, BDE-154, BDE-183, BDE-196, and technical octabromodiphenyl ether (DE-79) generated hydrodebrominated PBDEs along with up to 0.7-4 mass % BPs. UV absorption spectra were recorded to show that the para-substituted PBDEs and BPs are those predominately transformed because this structural feature causes a significant bathochromic shift of λmax to higher wavelength. A decrease of higher brominated BPs in favor of lower brominated BPs was observed with time. All possible substitution patterns on the BPs formed by the cleavage of the parent PBDEs and respective hydrodebromination products were observed. The main di- and tribromophenols detected were 2,4-diBP > 2,5-diBP and 2,4,6-triBP > 2,4,5-triBP on average. The irradiation conditions were similar to real-world scenarios and emphasized the environmental relevance of these photolysis products of PBDEs. The meta-substituted BPs can be used as markers to distinguish photolytic PBDE transformation products from naturally produced BPs, which exclusively feature bromo-substitutents in ortho- and para-positions.
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Affiliation(s)
- Paul Bendig
- Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany
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Sun C, Chang W, Ma W, Chen C, Zhao J. Photoreductive debromination of decabromodiphenyl ethers in the presence of carboxylates under visible light irradiation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:2370-2377. [PMID: 23383645 DOI: 10.1021/es3045604] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) have aroused global environmental concerns because of their toxicity and ubiquitousness in the biological and environmental systems. It is important to find an efficient method for their decontamination and to understand their chemical transformation in the environment. Here, we report that decabromodiphenyl ether (BDE209) undergoes efficient reductive debromination reactions under visible-light irradiation (≥ 420 nm) in the presence of various carboxylate anions that are common in the environmental media. The debromination reactions occur in a stepwise manner, producing a series of lower brominated PBDE congeners. Solvent-derived radials are observed by spin-trapping electron spin resonance (ESR) experiments during the photoreaction. Further experiments by the UV-vis absorption and isothermal titration calorimetry (ITC), combined with theoretical calculations, reveal a new photochemical debromination pathway based on the halogen binding interaction. According to this pathway, the formation of halogen-binding-based complex between PBDE and carboxylate enables the visible-light absorption and debromination of PBDEs, although neither PBDEs nor carboxylates have visible-light absorption. The halogen-bond-based photochemical debromination could find its application for our better understanding of the transformation process of PBDEs in the environment.
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Affiliation(s)
- Chunyan Sun
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China
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19
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Kajiwara N, Desborough J, Harrad S, Takigami H. Photolysis of brominated flame retardants in textiles exposed to natural sunlight. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2013; 15:653-660. [PMID: 23738364 DOI: 10.1039/c3em30887a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Photolytic transformation profiles of technical hexabromocyclododecane (HBCD) and technical decabromodiphenyl ether (DecaBDE) in flame-retarded textiles exposed to natural sunlight were compared. Textiles that contained approximately 4% HBCDs by weight showed no substantial loss of any of the HBCD diastereomers during the entire exposure period (371 days), indicating that they were resistant to sunlight, that is, that debromination and isomerization of HBCD diastereomers did not occur under the experimental conditions. Exposure of a textile treated with technical DecaBDE resulted in the formation of polybrominated dibenzofurans (PBDFs) as products of photodecomposition of polybrominated diphenyl ethers present in the technical DecaBDE. After 329 days of exposure, the total PBDF concentration reached a maximum of 27 000 ng g(-1), which was approximately 10 times the initial concentration. During the experiment, di- to hexa-BDF congener concentrations increased continuously. Although the concentrations of PBDFs in the textiles were 4–5 orders of magnitude lower than the concentrations of polybrominated diphenyl ethers, it is important to note that PBDFs were formed as a result of sunlight exposure during normal use of products treated with technical DecaBDE.
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Affiliation(s)
- Natsuko Kajiwara
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
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Bendig P, Blumenstein M, Hägele F, Vetter W. Hydrodebromination of decabromodiphenyl ether (BDE-209) in cooking experiments with salmon fillet. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:8521-8527. [PMID: 22846051 DOI: 10.1021/jf302137f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are environmental contaminants regularly detected in biota and food. Seafood has been identified as the major dietary source for human uptake. Fish is predominantly consumed after cooking, and this process may alter the actual human intake of contaminants. This study thus aimed to investigate the fate of PBDEs in this cooking process. Heating of fish fortified with 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209) at typical cooking conditions (200 °C, in plant oil) resulted in a decrease of its concentration in favor of the formation of lower brominated congeners. After 15 min, ∼25% of BDE-209 was transformed into nona- to octabrominated congeners. The major transformation route was BDE-209 → BDE-206 → BDE-196 and BDE-199. Low amounts of heptabrominated congeners as well as one hexabromodibenzofuran and a heptabromodibenzofuran isomer were also detected. However, penta- and tetrabrominated diphenyl ethers were not observed, and heating of BDE-47 did not produce new transformation products.
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Affiliation(s)
- Paul Bendig
- Institute of Food Chemistry, University of Hohenheim , Garbenstrasse 28, D-70599 Stuttgart, Germany
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Moon HB, Choi M, Yu J, Jung RH, Choi HG. Contamination and potential sources of polybrominated diphenyl ethers (PBDEs) in water and sediment from the artificial Lake Shihwa, Korea. CHEMOSPHERE 2012; 88:837-843. [PMID: 22542081 DOI: 10.1016/j.chemosphere.2012.03.091] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 03/30/2012] [Accepted: 03/31/2012] [Indexed: 05/31/2023]
Abstract
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 11.0ngL(-1) and from 1.3 to 18700ngg(-1)dryweight, 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.
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Affiliation(s)
- Hyo-Bang Moon
- Department of Environmental Marine Sciences, College of Science and Technology, Hanyang University, Ansan 426-791, Republic of Korea.
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Wang S, Hao C, Gao Z, Chen J, Qiu J. Effects of excited-state structures and properties on photochemical degradation of polybrominated diphenyl ethers: a TDDFT study. CHEMOSPHERE 2012; 88:33-38. [PMID: 22429844 DOI: 10.1016/j.chemosphere.2012.02.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 05/31/2023]
Abstract
This study presents new insight into the photochemical degradation of polybrominated diphenyl ethers (PBDEs), and it provides details about the structures and properties of 27 PBDE congeners in the electronically excited state using the time-dependent density functional theory method. Each PBDE congener exhibited remarkably different geometries in the ground state and the excited state. The significant lengthening of C-Br bond in each PBDE congener was observed in the excited state for the first time by theoretical calculation, which is directly involved in the photochemistry reductive debromination of n-BDE to (n-1)-BDE. Generally, the lengthening of C-Br bonds cannot occur at the para position. Furthermore, the calculated results demonstrated that the photoreactivity of PBDEs increased with an increase of bromination degree. It was also found that the pattern of Br substituents had an effect upon the photoreactivity of PBDEs. These findings suggest that the information obtained in the excited state is crucial to the mechanism explanation of the photochemical degradation of PBDEs.
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Affiliation(s)
- Se Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
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Heating of BDE-209 and BDE-47 in plant oil in presence of o,p′-DDT or iron(III) chloride can produce monochloro–polybromo diphenyl ethers. Food Chem Toxicol 2012; 50:1697-703. [DOI: 10.1016/j.fct.2012.02.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Revised: 02/17/2012] [Accepted: 02/20/2012] [Indexed: 11/29/2022]
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Monadjemi S, El Roz M, Richard C, Ter Halle A. Photoreduction of chlorothalonil fungicide on plant leaf models. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:9582-9589. [PMID: 21950599 DOI: 10.1021/es202400s] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Photodegradation is seldom considered at the surface of vegetation after crop spraying. Chlorothalonil, a broad-spectrum foliar fungicide with a very widespread use worldwide, was considered. To represent the waxy upper layer of leaves, tests were performed within thin paraffin wax films or in n-heptane. Laser flash photolysis together with steady-state irradiation in n-heptane allowed the determination of the photodegradation mechanisms Chlorothalonil ability to produce singlet oxygen was measured; noteworthy its efficiency is close to 100%. Additionally, chlorothalonil photodegradation mainly proceeds through reductive dechlorination. In these hydrophobic media, a radical mechanism was evidenced. Photochemical tests on wax films under simulated solar light show that formulated chlorothalonil is more reactive than pure chlorothalonil. The field-extrapolated half-life of photolysis on vegetation was estimated to 5.3 days. This value was compared to the half-lives of penetration and volatilization available in the literature. It appears that chlorothalonil dissipation from crops is ruled by both photodegradation and penetration. The relative importance of the two paths probably depends on meteorological factors and on physicochemical characteristics of the crop leaf cuticle.
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Affiliation(s)
- S Monadjemi
- Laboratoire de Photochimie Moléculaire et Macromoléculaire, Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
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Rosenfelder N, Bendig P, Vetter W. Stable carbon isotope analysis (δ13C values) of polybrominated diphenyl ethers and their UV-transformation products. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:2706-2712. [PMID: 21703744 DOI: 10.1016/j.envpol.2011.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 05/18/2011] [Accepted: 05/20/2011] [Indexed: 05/31/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are frequently detected in food and environmental samples. We used compound specific isotope analysis to determine the δ(13)C values of individual PBDEs in two technical mixtures. Within the same technical product (DE-71 or DE-79), BDE congeners were the more depleted in (13)C the higher brominated they were. In contrast, the products of light-induced hydrodebromination of BDE 47 and technical DE-79 were more enriched in (13)C because of more stable bonds between (13)C and bromine. As a result, the δ(13)C values of the irradiated solution progressed diametrically compared to those of the technical synthesis. The ratio of the δ(13)C values of BDE 47 to BDE 99 and of BDE 99 to BDE 153 are thus suggested as indicators to distinguish native technical products from transformation products. Ratios <1 are typical for native congeners (e.g. in DE-71) while the reversed ratio (>1) is typical of transformation products.
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Affiliation(s)
- Natalie Rosenfelder
- University of Hohenheim, Institute of Food Chemistry 170b, Garbenstr 28, D-70599 Stuttgart, Germany
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