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Eze OO, Ogbuene EB, Ibraheem O, Küster E, Eze CT. Novel flame retardants (NFRs) in e-waste: Environmental burdens, health implications, and recommendations for safety assessment and sustainable management. Toxicology 2024; 511:154037. [PMID: 39716513 DOI: 10.1016/j.tox.2024.154037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Revised: 12/03/2024] [Accepted: 12/17/2024] [Indexed: 12/25/2024]
Abstract
Novel flame retardants (NFRs) have emerged as chemicals of environmental health concern due to their widespread use as an alternative to polybrominated diphenyl ethers (PBDE) in electrical and electronic devices. Humans and ecosystems are under threat because of e-waste recycling procedures that may emit NFRs and other anthropogenic chemicals into the e-waste workplace and the surrounding environment. The individual toxicity of NFRs including novel brominated flame retardants (NBFRs), their combined effects and the underlying mechanisms of toxicity have remained poorly understood. Exposure assessment as well as chemical safety testing should focus on prioritizing N(B)FRs for regulation and management. Here, the occurrence of N(B)FRs in the vicinity and surroundings of e-waste recycling sites are presented. Important knowledge gaps and prospects for a more integrated, harmonized, and mechanistically positioned risk assessment strategy for N(B)FRs as well as possible economically feasible and environmentally sustainable approaches for removing them from complex matrices are highlighted. Overall, data in the ng to µg-ranges of N(B)FR in soil, dust, sediment, water and fish were found. Dust and soil sample concentrations ranged from the low ng to low µg/g range while water concentrations were always in the low ng/L range (∼0.5 to ∼4 ng/L). Concentration in fish was usually in the range of 3- ∼300 ng/g with two substances in the low to medium-high µg/g range (DBDPE, BTBPE). From the 20 N(B)FR analysed in sediment samples only 10 were above detection limit. Most chemicals were found in a low ng/g range.
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Affiliation(s)
- Obianuju Oluchukwu Eze
- Helmholtz Centre for Environmental Research - UFZ, Department Ecotoxicology, Leipzig, Germany
| | - Emeka Bright Ogbuene
- Centre for Environmental Management and Control, University of Nigeria, Enugu Campus, Nigeria
| | - Omodele Ibraheem
- Department of Biochemistry, Faculty of Science, Federal University Oye-Ekiti, Ekiti State, Nigeria
| | - Eberhard Küster
- Helmholtz Centre for Environmental Research - UFZ, Department Ecotoxicology, Leipzig, Germany.
| | - Chukwuebuka ThankGod Eze
- Helmholtz Centre for Environmental Research - UFZ, Department Ecotoxicology, Leipzig, Germany; Entity of In Vitro Toxicology and Dermato-Cosmetology, Department of Pharmaceutical and Pharmacological Sciences, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
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Rawn DFK, Corrigan C, Ménard C, Sun WF, Breton F, Arbuckle TE. Novel halogenated flame retardants in Canadian human milk from the MIREC study (2008-2011). CHEMOSPHERE 2024; 350:141065. [PMID: 38159732 DOI: 10.1016/j.chemosphere.2023.141065] [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: 11/14/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
Novel halogenated flame retardants (NHFRs) have been developed to replace those brominated flame retardants that have been restricted due to their persistence, bioaccumulation potential and toxicity, therefore, it is important to determine whether these replacement products are present at detectable concentrations in Canadians. NHFRs were measured in human milk samples (n = 541) collected from across Canada between 2008 and 2011, which is the first pan-Canadian dataset for these chemicals in human milk. Among the 15 measured NHFRs and eight methoxy-polybrominated diphenyl ethers (MeO-PBDEs), nine NHFRs and two MeO-PBDEs (6-MeO-PBDE 47 and 2-MeO-PBDE 68) were detected at a frequency of more than 9%. Despite benzene, 1,1'-(1,2-ethanediyl)bis [2,3,4,5,6-pentabromo-]/decabromodiphenylethane [DBDPE] being detected less frequently than the other observed NHFRs, its relative contribution to the sum of nine NHFRs was important when it was present. The maximum ΣNHFR concentration in Canadian human milk was 6930 pg g-1 lipid while the maximum ΣMeO-PBDEs was 1600 pg g-1 lipid. While most NHFR concentrations were significantly correlated with each other, no relationships between maternal age, parity or pre-pregnancy BMI were identified with ΣNHFR concentrations in the milk. In contrast, maternal age was significantly correlated with ΣMeO-PBDE concentrations (r = 0.237, p < 0.001). ΣNHFR concentrations were similarly not related to maternal education, although ΣMeO-PBDE concentrations were found to be higher in milk from women who had graduated from trade schools relative to the other education levels considered. NHFR detection frequency and concentrations observed in the Canadian human milk seem to align well with Europe.
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Affiliation(s)
- Dorothea F K Rawn
- Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Sir Frederick Banting Research Centre, 251 Sir Frederick Banting Driveway, Address Locator 2203C, Tunney's Pasture, Ottawa, ON, K1A 0K9, Canada.
| | - Catherine Corrigan
- Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Sir Frederick Banting Research Centre, 251 Sir Frederick Banting Driveway, Address Locator 2203C, Tunney's Pasture, Ottawa, ON, K1A 0K9, Canada
| | - Cathie Ménard
- Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Sir Frederick Banting Research Centre, 251 Sir Frederick Banting Driveway, Address Locator 2203C, Tunney's Pasture, Ottawa, ON, K1A 0K9, Canada
| | - Wing-Fung Sun
- Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Sir Frederick Banting Research Centre, 251 Sir Frederick Banting Driveway, Address Locator 2203C, Tunney's Pasture, Ottawa, ON, K1A 0K9, Canada
| | - François Breton
- Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Sir Frederick Banting Research Centre, 251 Sir Frederick Banting Driveway, Address Locator 2203C, Tunney's Pasture, Ottawa, ON, K1A 0K9, Canada; Generic Drugs Division, Bureau of Pharmaceutical Sciences, Health Products and Food Branch, Health Canada, 101 Tunney's Pasture Driveway, Address Locator 0201D, Tunney's Pasture, Ottawa, ON, K1A 0K9, Canada
| | - Tye E Arbuckle
- Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Ave, Ottawa, ON, K1A 0K9, Canada
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Niu D, Xiao Y, Chen S, Du X, Qiu Y, Zhu Z, Yin D. Evaluation of the oral bioaccessibility of legacy and emerging brominated flame retardants in indoor dust. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:99735-99747. [PMID: 37620695 DOI: 10.1007/s11356-023-29304-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023]
Abstract
Indoor dust is the main source of human exposure to brominated flame retardants (BFRs). In this study, in vitro colon-extended physiologically-based extraction test (CE-PBET) with Tenax as a sorptive sink was applied to evaluate the oral bioaccessibility of twenty-two polybrominated diphenyl ethers (PBDEs) and seven novel BFRs (NBFRs) via indoor dust ingestion. The mean bioaccessibilities of two NBFRs pentabromotoluene (PBT) and 1,2-Bis(2,4,6-tribromophenoxy) ethane (BTBPE) were first proposed, reaching 36.0% and 26.7%, respectively. In order to maintain homeostasis of the gastrointestinal tract, 0.4 g Tenax was added in CE-PEBT, which increased BFRs bioaccessibility by up to a factor of 1.4-1.9. The highest bioaccessibility of legacy PBDEs was tri-BDEs (73.3%), while 2-ethylhexyl-tetrabromo-benzoate (EHTBB), one of penta-BDE alternatives, showed the highest (62.2%) among NBFRs. The influence of food nutrients, liquid to solid (L/S) ratio, and octanol-water partition coefficient (Kow) on bioaccessibility was assessed. The oral bioaccessibility of BFRs increased with existence of protein or carbohydrate while lipid did the opposite. The bioaccessibilities of PBDEs and NBFRs were relatively higher with 200:1 L/S ratio. PBDEs bioaccessibility generally decreased with increasing LogKow. No significant correlation was observed between NBFRs bioaccessibility and LogKow. This study comprehensively evaluated the bioaccessibilities of legacy and emerging BFRs via dust ingestion using Tenax-assisted CE-PBET, and highlighted the significance to fully consider potential influencing factors on BFRs bioaccessibility in further human exposure estimation.
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Affiliation(s)
- Dong Niu
- Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Yao Xiao
- Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Shiyan Chen
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, China
| | - Xinyu Du
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201206, China
| | - Yanling Qiu
- Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| | - Zhiliang Zhu
- Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Daqiang Yin
- Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
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Guo X, Liu B, Liu H, Du X, Chen X, Wang W, Yuan S, Zhang B, Wang Y, Guo H, Zhang H. Research advances in identification procedures of endocrine disrupting chemicals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:83113-83137. [PMID: 37347330 DOI: 10.1007/s11356-023-27755-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/15/2023] [Indexed: 06/23/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are increasingly concerned substance endangering human health and environment. However, there is no unified standard for identifying chemicals as EDCs, which is also controversial internationally. In this review, the procedures for EDC identification in different organizations/countries were described. Importantly, three aspects to be considered in identifying chemical substances as EDCs were summarized, which were mechanistic data, animal experiments, and epidemiological information. The relationships between them were also discussed. To elaborate more clearly on these three aspects of evidence, scientific data on some chemicals including bisphenol A, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane and perchlorate were collected and evaluated. Altogether, the above three chemicals were assessed for interfering with hormones and elaborated their health hazards from macroscopic to microscopic. This review is helpful for standardizing the identification procedure of EDCs.
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Affiliation(s)
- Xing Guo
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Bing Liu
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Haohao Liu
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Xinghai Chen
- Department of Chemistry and Biochemistry, St Mary's University, San Antonio, TX, USA
| | - Wenjun Wang
- College of Nursing, Jining Medical University, Jining, Shandong, People's Republic of China
| | - Shumeng Yuan
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Bingyu Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Yongshui Wang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Hongxiang Guo
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China.
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Boosting both flame retardancy and mechanical properties of carbon fiber/epoxy composites via polycyclic phosphorus-nitrogen imidazole derivative. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Nephrotoxicity of Flame Retardants: An Understudied but Critical Toxic Endpoint. CURRENT OPINION IN TOXICOLOGY 2022. [DOI: 10.1016/j.cotox.2022.100359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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In situ localization of tris(2,3-dibromopropyl) isocyanurate in mouse organs by MALDI-IMS with auxiliary matrix strategy. Talanta 2021; 235:122723. [PMID: 34517591 DOI: 10.1016/j.talanta.2021.122723] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/13/2021] [Accepted: 07/16/2021] [Indexed: 11/24/2022]
Abstract
Tris(2,3-dibromopropyl) isocyanurate (TBC) is one of the novel brominated flame retardants that has been widely used in consumer goods. Humans may be exposed to TBC daily. Studies showed that TBC can induce significant toxicity. However, there is currently no report on its in situ localization in organs. In this study, we aimed to develop a reliable and reproductive method to determine the in situ localization of TBC in mouse organs by matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS). As commercially available matrices were not able to detect TBC in tissue section, we then developed a novel MALDI-IMS method based on 1,5-diaminonaphthalene hydrochloride and silver trifluoromethanesulfonate (NDA/AgOTf) as the matrix for the in situ localization of TBC. AgOTf used as the auxiliary matrix in the negative-ion mode showed an excellent MS signal of TBC. The detection limit of [2AgOTf + Br]- was at the μg/mL level. The developed MALDI-IMS method was successfully employed to obtain the TBC spatial distribution in the mouse organs collected from mice exposed to 160 mg/kg/day of TBC for 30 days. High-pressure liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS) was also used to evaluate the accumulation of TBC in liver, kidney, heart, and brain. The combination of MALDI-IMS and HPLC-MS/MS showed that TBC can accumulate in mice organs and it is mainly distributed in the renal parenchyma. In summary, an innovative method was developed for the analysis of TBC spatial distribution by MALDI-IMS using a novel NDA/AgOTf matrix, extending the application of MALDI-IMS in environmental pollutants.
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8
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The brominated flame retardants TBECH and DPTE alter prostate growth, histology and gene expression patterns in the mouse. Reprod Toxicol 2021; 102:43-55. [PMID: 33848595 DOI: 10.1016/j.reprotox.2021.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/22/2021] [Accepted: 04/07/2021] [Indexed: 10/21/2022]
Abstract
The brominated flame retardants (BFRs), 1,2-dibromo-4-(1,2 dibromoethyl)cyclohexane (TBECH) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) bind to the androgen receptor (AR). in vitro bioassays have shown that TBECH is a potent androgen agonist while DPTE is a potent AR antagonist. Both TBECH and DPTE alter gene expression associated with AR regulation. However, it remains to be determined if TBECH and DPTE can affect the prostate. For this reason, we exposed CD1 mice to a 1:1 mixture of TBECH diastereomers α and β, a 1:1 mixture of γ and δ, and to DPTE, and tested their effects on prostate growth, histology and gene expression profiles. Castrated mice were used to study the androgenic effects of TBECHαβ and TBECHγδ while the antagonistic effects of DPTE were studied in non-castrated mice. We observed that testosterone and TBECHγδ increased body and prostate weights while TBECHαβ affected neither of them; and that DPTE had no effect on body weight but reduced prostate weight drastically. Histomorphometric analysis of the prostate revealed epithelial and glandular alterations in the TBECHγδ group comparable to those in testosterone group while alterations in the TBECHαβ group were less pronounced. DPTE displayed androgen antagonist activity reminiscent of castration. The transcription profile of the prostate was altered by castration and exposure to testosterone and to TBECHγδ reversed several of these changes. Testosterone and TBECHγδ also regulated the expression of several androgen responsive genes implicated in prostate growth and cancer. While DPTE resulted in a drastic reduction in prostate weight, it only affected a small number of genes. The results indicate that TBECHγδ and DPTE are of high human health concern as they may contribute to changes in prostate growth, histology and function.
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Marteinson SC, Bodnaryk A, Fry M, Riddell N, Letcher RJ, Marvin C, Tomy GT, Fernie KJ. A review of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane in the environment and assessment of its persistence, bioaccumulation and toxicity. ENVIRONMENTAL RESEARCH 2021; 195:110497. [PMID: 33232751 DOI: 10.1016/j.envres.2020.110497] [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: 08/20/2020] [Revised: 11/12/2020] [Accepted: 11/14/2020] [Indexed: 06/11/2023]
Abstract
Following the ban of many historically-used flame retardants (FRs), numerous replacement chemicals have been produced and used in products, with some being identified as environmental contaminants. One of these replacement flame retardants is 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (DBE-DBCH; formerly abbreviated as TBECH), which to date has not been identified for risk assessment and potential regulation. DBE-DBCH technical mixtures consist largely of α- and β-diastereomers with trace amounts of γ- and δ-DBE-DBCH. The α- and β-isomers are known contaminants in various environmental media. While current global use and production volumes of DBE-DBCH are unknown, recent studies identified that DBE-DBCH concentrations were among the highest of the measured bromine-based FRs in indoor and urban air in Europe. Yet our mass balance fugacity model and modeling of the physical-chemical properties of DBE-DBCH estimated only 1% partitioning to air with a half-life of 2.2 d atmospherically. In contrast, our modeling characterized DBE-DBCH adsorbing strongly to suspended particulates in the water column (~12%), settling onto sediment (2.5%) with minimal volatilization, but with most partitioning and adsorbing strongly to soil (~85%) with negligible volatilization and slow biodegradation. Our modeling further predicted that organisms would be exposed to DBE-DBCH through partitioning from the dissolved aquatic phase, soil, and by diet, and given its estimated logKow (5.24) and a half-life of 1.7 d in fish, DBE-DBCH is expected to bioaccumulate into lipophilic tissues. Low concentrations of DBE-DBCH are commonly measured in biota and humans, possibly because evidence suggests rapid metabolism. Yet toxicological effects are evident at low exposure concentrations: DBE-DBCH is a proven endocrine disruptor of sex and thyroid hormone pathways, with in vivo toxic effects on reproductive, metabolic, and other endpoints. The objectives of this review are to identify the current state of knowledge concerning DBE-DBCH through an evaluation of its persistence, potential for bioaccumulation, and characterization of its toxicity, while identifying areas for future research.
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Affiliation(s)
- Sarah C Marteinson
- Environment and Climate Change Canada, 867 Lakeshore Rd, Burlington, ON, L7S 1A1, Canada
| | - Anjelica Bodnaryk
- University of Manitoba, Department of Biological Sciences, Winnipeg, MB, R3T 2N2, Canada
| | - Mark Fry
- University of Manitoba, Department of Biological Sciences, Winnipeg, MB, R3T 2N2, Canada
| | - Nicole Riddell
- Wellington Laboratories, 345 Southgate Dr., Guelph, ON, N1G 3M5, Canada
| | - Robert J Letcher
- Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada
| | - Chris Marvin
- Environment and Climate Change Canada, 867 Lakeshore Rd, Burlington, ON, L7S 1A1, Canada
| | - Gregg T Tomy
- University of Manitoba, Department of Chemistry, Winnipeg, MB, R3T 2N2, Canada
| | - Kim J Fernie
- Environment and Climate Change Canada, 867 Lakeshore Rd, Burlington, ON, L7S 1A1, Canada.
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Dong L, Wang S, Qu J, You H, Liu D. New understanding of novel brominated flame retardants (NBFRs): Neuro(endocrine) toxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111570. [PMID: 33396099 DOI: 10.1016/j.ecoenv.2020.111570] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 06/12/2023]
Abstract
Traditional brominated flame retardants (BFRs) negatively affect the environment and human health, especially in the sensitive (developing) nervous system. Considering the physicochemical similarities between novel brominated flame retardants (NBFRs) and BFRs, more and more evidence reveals the neurotoxic effects of NBFRs. We reviewed the neuro(endocrine) toxic effects of NBFRs in vivo and in vitro and discussed their action mechanisms based on the available information. The neurotoxic potential of NBFRs has been demonstrated through direct neurotoxicity and disruption of the neuroendocrine system, with adverse effects on neurobehavioral and reproductive development. Mechanistic studies have shown that the impact of NBFRs is related to the complex interaction of neural and endocrine signals. From disrupting the gender differentiation of the brain, altering serum thyroid/sex hormone levels, gene/protein expression, and so on, to interfere with the feedback effect between different levels of the HPG/HPT axis. In this paper, the mechanism of neurotoxic effects of NBFRs is explored from a new perspective-neuro and endocrine interactions. Gaps in the toxicity data of NBFRs in the neuroendocrine system are supplemented and provide a broader dataset for a complete risk assessment.
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Affiliation(s)
- Liying Dong
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Shutao Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jinze Qu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Hong You
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
| | - Dongmei Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
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11
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Sutha J, Anila PA, Umamaheswari S, Ramesh M, Narayanasamy A, Poopal RK, Ren Z. Biochemical responses of a freshwater fish Cirrhinus mrigala exposed to tris(2-chloroethyl) phosphate (TCEP). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:34369-34387. [PMID: 32557019 DOI: 10.1007/s11356-020-09527-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/29/2020] [Indexed: 05/22/2023]
Abstract
Freshwater fish Cirrhinus mrigala were exposed to tris(2-chloroethyl) phosphate (TCEP) with three different concentrations (0.04, 0.2, and 1 mg/L) for a period of 21 days. During the study period, thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) levels were significantly (p < 0.05) inhibited. The superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and lipid peroxidation (LPO) levels were increased significantly (p < 0.05) in gills, liver, and kidney tissues, whereas glutathione (GSH) and glutathione peroxidase (GPx) (except liver tissue) activities were inhibited when compared to the control group. Likewise, exposure to TCEP significantly (p < 0.05) altered the biochemical (glucose and protein) and electrolyte (sodium, potassium, and chloride) levels of fish. Light microscopic studies exhibited series of histopathological anomalies in the gills, liver, and kidney tissues. The present study reveals that TCEP at tested concentrations causes adverse effects on fish and the studied biomarkers could be used for monitoring the ecotoxicity of organophosphate esters (OPEs).
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Affiliation(s)
- Jesudass Sutha
- Unit of Toxicology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, India
| | - Pottanthara Ashokan Anila
- Unit of Toxicology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, India
| | - Sathisaran Umamaheswari
- Unit of Toxicology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, India
| | - Mathan Ramesh
- Unit of Toxicology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, India.
| | - Arul Narayanasamy
- Disease Proteiomics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, 641046, India
| | - Rama-Krishnan Poopal
- Institute of Environment and Ecology, Shandong Normal University, Jinan, People's Republic of China
| | - Zongming Ren
- Institute of Environment and Ecology, Shandong Normal University, Jinan, People's Republic of China.
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12
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Wang X, Wei L, Zhu J, He B, Kong B, Jin Y, Fu Z. Tetrabromoethylcyclohexane (TBECH) exhibits immunotoxicity in murine macrophages. ENVIRONMENTAL TOXICOLOGY 2020; 35:159-166. [PMID: 31696622 DOI: 10.1002/tox.22852] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 09/13/2019] [Accepted: 09/14/2019] [Indexed: 06/10/2023]
Abstract
Tetrabromoethylcyclohexane (TBECH) has been linked to endocrine disruption, hepatotoxicity, and reproductive toxicity. However, its immunotoxicity remains largely unknown. In the present study, RAW 264.7 cells, mouse macrophage cell line, were exposed to TBECH. MTT assays showed that TBECH significantly enhanced lactate dehydrogenase (LDH) release in RAW 264.7 cells. The mRNA expression of some proapoptotic genes was upregulated by TBECH. Accordingly, TBECH elevated caspase-3 activity. In addition, TBECH upregualted the mRNA levels of some pro-inflammatory cytokines, whereas it downregulated LPS-stimulated mRNA expression of these cytokines. Moreover, TBECH downregulated the mRNA expression of selected antigen presenting-related genes. Furthermore, TBECH increased reactive oxygen species level, reduced glutathione content and the activities of superoxide dismutase and catalase, and upregulated the mRNA expression of selected oxidative stress-related genes. The obtained data demonstrated that TBECH exhibits immunotoxicity in macrophages, and will help to evaluate its health risks.
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Affiliation(s)
- Xia Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Lai Wei
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Jianbo Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Bingnan He
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Baida Kong
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yuanxiang Jin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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Xiong P, Yan X, Zhu Q, Qu G, Shi J, Liao C, Jiang G. A Review of Environmental Occurrence, Fate, and Toxicity of Novel Brominated Flame Retardants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13551-13569. [PMID: 31682424 DOI: 10.1021/acs.est.9b03159] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Use of legacy brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), has been reduced due to adverse effects of these chemicals. Several novel brominated flame retardants (NBFRs), such decabromodiphenyl ethane (DBDPE) and bis(2,4,6-tribromophenoxy) ethane (BTBPE), have been developed as replacements for PBDEs. NBFRs are used in various industrial and consumer products, which leads to their ubiquitous occurrence in the environment. This article reviews occurrence and fate of a select group of NBFRs in the environment, as well as their human exposure and toxicity. Occurrence of NBFRs in both abiotic, including air, water, dust, soil, sediment and sludge, and biotic matrices, including bird, fish, and human serum, have been documented. Evidence regarding the degradation, including photodegradation, thermal degradation and biodegradation, and bioaccumulation and biomagnification of NBFRs is summarized. The toxicity data of NBFRs show that several NBFRs can cause adverse effects through different modes of action, such as hormone disruption, endocrine disruption, genotoxicity, and behavioral modification. The primary ecological risk assessment shows that most NBFRs exert no significant environmental risk, but it is worth noting that the result should be carefully used owing to the limited toxicity data.
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Affiliation(s)
- Ping Xiong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xueting Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Qingqing Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Guangbo Qu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
- Institute of Environment and Health , Jianghan University , Wuhan , Hubei 430056 , China
| | - Jianbo Shi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
- Institute of Environment and Health , Jianghan University , Wuhan , Hubei 430056 , China
| | - Chunyang Liao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
- Institute of Environment and Health , Jianghan University , Wuhan , Hubei 430056 , China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- College of Resources and Environment , University of Chinese Academy of Sciences , Beijing 100049 , China
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Hexabromocyclododecane (HBCD): A case study applying tiered testing for human health risk assessment. Food Chem Toxicol 2019; 131:110581. [DOI: 10.1016/j.fct.2019.110581] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 10/26/2022]
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15
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Stojak BL, van Ginkel RA, Ivanco TL, Tomy GT, Fry WM. Acute β-tetrabromoethylcyclohexane (β-TBECH) treatment inhibits the electrical activity of rat Purkinje neurons. CHEMOSPHERE 2019; 231:301-307. [PMID: 31129411 DOI: 10.1016/j.chemosphere.2019.05.102] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 06/09/2023]
Abstract
Brominated flame-retardants are environmentally pervasive and persistent synthetic chemicals, some of which have been demonstrated to disrupt neuroendocrine signaling and electrical activity of neurons. 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (TBECH) lacks the toxicity of other classes of BFRs, however its safety is still questioned, as little is known of its neurological effects. Therefore, we sought to determine if TBECH could acutely alter the electrical activity of Purkinje neurons maintained in vitro. Briefly, cerebella from gestational day 20 rats were dissociated and maintained for up to three weeks in culture. Action potentials of Purkinje neurons were detected by cell-attached patch clamp before, during, and after application of β-TBECH. β-TBECH decreased action potential activity in a dose-dependent manner with an apparent EC50 of 396 nM. β-TBECH did not significantly alter the coefficient of variation, a measure of the regularity of firing, suggesting that the mechanism of β-TBECH's effects on firing frequency may be independent of Purkinje neuron intracellular calcium handling. Because levels of β-TBECH in exposed individuals may not approach the EC50, these data suggest that any abnormal neurodevelopment or behavior linked with β-TBECH exposure may result from endocrinological effects as opposed to direct disruption of electrical activity.
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Affiliation(s)
- Brittany L Stojak
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Rebecca A van Ginkel
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Tammy L Ivanco
- Department of Psychology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Gregg T Tomy
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - W Mark Fry
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
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16
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Rat strain response differences upon exposure to technical or alpha hexabromocyclododecane. Food Chem Toxicol 2019; 130:284-307. [DOI: 10.1016/j.fct.2019.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 01/14/2023]
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17
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Ruan Y, Zhang K, Lam JCW, Wu R, Lam PKS. Stereoisomer-specific occurrence, distribution, and fate of chiral brominated flame retardants in different wastewater treatment systems in Hong Kong. JOURNAL OF HAZARDOUS MATERIALS 2019; 374:211-218. [PMID: 31005053 DOI: 10.1016/j.jhazmat.2019.04.041] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/03/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
This study investigated the occurrence and fate of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), two chiral brominated flame retardants (BFRs) with sixteen different stereoisomers, in four Hong Kong wastewater treatment plants (WWTPs) featuring diverse treatment processes during a two-year sampling campaign. More effective HBCD removal was achieved via biodegradation as compared to sludge sorption, whereas both chemically enhanced primary treatment and secondary treatment yielded high TBECH elimination (>90%). α-HBCD (54-75%) predominated in all samples, and its proportions were increased in effluent as compared to influent and sludge. α- and β-TBECH (72.3-84.4% in total) were the predominant TBECH diastereomers, with a proportional shift from the latter to the former diastereomer mostly observed after treatment. More rapid biodegradation and preferential sorption of γ-HBCD as compared to α-HBCD as well as β-TBECH as compared to α-TBECH might account for this changing pattern. This is the first study to report the enantiomer-specific behavior of chiral BFRs in different wastewater treatment processes. A preferential elimination of (+)-α- and (+)-γ-HBCD and E2-β-TBECH (the second enantiomeric elution order) took place consistently after biological treatment, possibly due to enantioselective adsorption and microbial degradation. Our results highlight the importance of conducting enantiospecific analysis for chiral pollutants in wastewater samples.
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Affiliation(s)
- Yuefei Ruan
- State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Kai Zhang
- State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China
| | - James C W Lam
- State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China; Department of Science and Environmental Studies, The Education University of Hong of Kong, Hong Kong Special Administrative Region, China.
| | - Rongben Wu
- State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China; Department of Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Paul K S Lam
- State Key Laboratory of Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, City University of Hong Kong, Hong Kong Special Administrative Region, China; Department of Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region, China.
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18
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Wang X, Wei L, Wang Y, He B, Kong B, Zhu J, Jin Y, Fu Z. Evaluation of development, locomotor behavior, oxidative stress, immune responses and apoptosis in developing zebrafish (Danio rerio) exposed to TBECH (tetrabromoethylcyclohexane). Comp Biochem Physiol C Toxicol Pharmacol 2019; 217:106-113. [PMID: 30528700 DOI: 10.1016/j.cbpc.2018.12.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/30/2018] [Accepted: 12/02/2018] [Indexed: 12/21/2022]
Abstract
Tetrabromoethylcyclohexane (TBECH), as one emerging brominated flame retardants, is ubiquitous in the environment, including water and aquatic organisms. TBECH was found to exhibit endocrine-disrupting effects in different models, whereas a survey of comprehensive toxic effects of TBECH on zebrafish is limited. In the present study, zebrafish (Danio rerio) were waterborne exposed continuously to TBECH from embryonic stage (3 h post-fertilization (hpf)) to the time when the respective parameters were evaluated. Exposure to TBECH reduced hatchability of zebrafish embryos at 72 and 96 hpf, diminished heart rate of zebrafish larvae at 48 hpf, and increased malformation in zebrafish larvae at 96 hpf. In addition, exposure to TBECH diminished free swimming distance both in the light and under a photoperiod of 10 min light/10 min dark cycles in zebrafish larvae at 6 days post-fertilization (dpf). Moreover, exposure to TBECH elevated activities of superoxide dismutase (SOD) and catalase (CAT), malondialdehyde (MDA) content, whereas it reduced glutathione (GSH) content, in zebrafish larvae at 6 dpf. Accordingly, RT-qPCR analysis demonstrated that TBECH exposure increased the mRNA levels of sod1, sod2, cat, and gpx1 in zebrafish larvae at 6 dpf. With respect to the immune aspect, the mRNA levels of pro-inflammatory genes, including il-1b, il-6, il-8, and tnfa, in larval zebrafish at 6 dpf were increased by exposure to TBECH, while pretreatment with TBECH inhibited 24 h of exposure to LPS-stimulated elevation in the mRNA levels of the abovementioned four pro-inflammatory genes in zebrafish larvae at 6 dpf. Furthermore, TBECH treatment increased caspase-3 enzyme activities and regulated apoptosis-related genes in larval zebrafish at 6 dpf. Taken together, the data obtained in this study demonstrated that TBECH caused developmental and locomotor behavioral toxicity, immunotoxicity, oxidative stress and proapoptotic effects in early life zebrafish. The present study will help to understand the comprehensive toxicity of TBECH in zebrafish.
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Affiliation(s)
- Xia Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Lai Wei
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yi Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Bingnan He
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Baida Kong
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jianbo Zhu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yuanxiang Jin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China.
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19
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Marteinson SC, Fernie KJ. Is the current-use flame retardant, DBE-DBCH, a potential obesogen? Effects on body mass, fat content and associated behaviors in American kestrels. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 169:770-777. [PMID: 30597775 DOI: 10.1016/j.ecoenv.2018.11.104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 11/21/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
The current-use brominated flame retardant, 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (DBE-DBCH), is capable of perturbing sex steroid and thyroid hormone pathways in vitro and in vivo. Chemicals with this capability may also disrupt metabolic processes and are candidate obesogens, but this potential has not yet been determined for DBE-DBCH. Our objective was to examine gross biomarkers of metabolic disruption in captive American kestrels. Birds were exposed by diet to the β isomer at the environmentally relevant dose of 0.239 ng β-DBE-DBCH/g kestrel/day, from 30 days (d) prior to pairing through until chicks hatched (82 d) (n = 30 breeding pairs) or for 28 d (n = 16 pre-breeding pairs), and were compared with vehicle-only exposed controls. Body mass was assessed throughout the breeding season at biologically relevant time points, flight and feeding behavior was measured in 5-min samples daily, and plasma triglycerides and cholesterol were assessed at d10 of brood rearing. Treated males were heavier than controls at pairing (p = 0.051), the final week of courtship (p = 0.061), and at d10 (p = 0.012) and d20 of brood rearing (p = 0.051); β-DBE-DBCH-exposed breeding females were similar in weight to control females. Treated birds tended to have higher plasma triglycerides (p = 0.078), which for females, was positively associated with body mass (p = 0.019). Heavier breeding males had higher plasma concentrations of testosterone and total thyroxine (p ≤ 0.046). Overall, both sexes exposed to β-DBE-DBCH demonstrated reduced flight behavior and increased feeding behavior during courtship. In the pre-breeding pairs, treated male and female kestrels had a higher percentage of body fat than respective controls (p = 0.045). These results demonstrate that β-DBE-DBCH elicited inappropriate fat and weight gain in adult American kestrels, consistent with their increased feeding, reduced flight activity and endocrine changes, and suggests that DBE-DBCH may be an obesogen warranting further research to test this hypothesis.
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Affiliation(s)
- Sarah C Marteinson
- Ecotoxicology & Wildlife Health Division, Science & Technology Branch, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - Kim J Fernie
- Ecotoxicology & Wildlife Health Division, Science & Technology Branch, Environment and Climate Change Canada, Burlington, Ontario, Canada.
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20
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Ruan Y, Zhang X, Qiu JW, Leung KMY, Lam JCW, Lam PKS. Stereoisomer-Specific Trophodynamics of the Chiral Brominated Flame Retardants HBCD and TBECH in a Marine Food Web, with Implications for Human Exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8183-8193. [PMID: 29939731 DOI: 10.1021/acs.est.8b02206] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Stereoisomers of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) and 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (TBECH) were determined in sediments and 30 marine species in a marine food web to investigate their trophic transfer. Lipid content was found to affect the bioaccumulation of ΣHBCD and ΣTBECH in these species. Elevated biomagnification of each diastereomer from prey species to marine mammals was observed. For HBCD, biota samples showed a shift from γ- to α-HBCD when compared with sediments and technical mixtures; trophic magnification potential of (-)-α- and (+)-α-HBCD were observed in the food web, with trophic magnification factors (TMFs) of 11.8 and 8.7, respectively. For TBECH, the relative abundance of γ- and δ-TBECH exhibited an increasing trend from abiotic matrices to biota samples; trophic magnification was observed for each diastereomer, with TMFs ranging from 1.9 to 3.5. The enantioselective bioaccumulation of the first eluting enantiomer of δ-TBECH in organisms at higher TLs was consistently observed across samples. This is the first report on the trophic transfer of TBECH in the food web. The estimated daily intake of HBCD for Hong Kong residents was approximately 16-times higher than that for the general population in China, and the health risk to local children was high, based on the relevant available reference dose.
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Affiliation(s)
| | - Xiaohua Zhang
- Department of Science and Environmental Studies , The Education University of Hong of Kong , Hong Kong SAR , China
| | - Jian-Wen Qiu
- Department of Biology , Hong Kong Baptist University , Hong Kong SAR , China
| | - Kenneth M Y Leung
- The Swire Institute of Marine Science and School of Biological Sciences , The University of Hong Kong , Hong Kong SAR , China
| | - James C W Lam
- Department of Science and Environmental Studies , The Education University of Hong of Kong , Hong Kong SAR , China
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21
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Carbon Fibers Decorated by Polyelectrolyte Complexes Toward Their Epoxy Resin Composites with High Fire Safety. CHINESE JOURNAL OF POLYMER SCIENCE 2018. [DOI: 10.1007/s10118-018-2164-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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22
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Dai G, Wang D, Dong H. Effects of recombinant human growth hormone on protein malnutrition and IGF-1 and IL-2 gene expression levels in chronic nephrotic syndrome. Exp Ther Med 2018; 15:4167-4172. [PMID: 29725365 PMCID: PMC5920232 DOI: 10.3892/etm.2018.5953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/11/2017] [Indexed: 11/05/2022] Open
Abstract
The aim of the study was to investigate the effects of recombinant human growth hormone on protein malnutrition and insulin-like growth factor-1 (IGF-1) and interleukin-2 (IL-2) gene expressions in chronic nephrotic syndrome. Eighty patients with chronic nephrotic syndrome were admitted to our hospital. The patients were included in the study period from January 2015 to December 2016 and were divided into two groups (40 cases in each group) according to the random number method. All the patients enrolled received symptomatic and supportive treatment. The observation group was injected subcutaneously with recombinant human growth hormone, while the control group was treated with Shenyankangfu tablets. The recovery time of the clinical symptoms, change in serum protein, caloric intake and protein metabolism after intervention were compared between the two groups. Changes in serum cystatin C, IGF-1 and IL-2 before intervention, and at 1 week, 1 month and 3 months after intervention were detected, and the adverse reactions in the two groups were observed during the treatment. After intervention, the improvement time of proteinuria, hypoproteinemia, edema and hyperlipidemia in the observation group was significantly shorter than that in the control group (P<0.05). The expression of transferrin, pre-albumin, albumin and total protein in the observation group was significantly superior increased compared to those in the observation group prior to intervention and the control group after intervention (P<0.05). In addition the caloric intake, protein intake and urea nitrogen survival rate in the observation group were significantly superior to those in the observation group prior to intervention and the control group after intervention (P<0.05). At 1 week, 1 month and 3 months after intervention, the levels of serum cystatin C, IGF-1 and IL-2 in the observation group were markedly obviously lower than those in the control group during the same period (P<0.05). The total proportion of allergy, systemic pruritus, nausea and vomiting, abdominal distension and abdominal pain in the observation group was obviously lower than that in the control group (P<0.05). Compared with the traditional Chinese medicine Shenyankangfu tablets applied in the control group, the recombinant human growth hormone used for patients with chronic nephrotic syndrome can improve the clinical symptoms more quickly, regulate the protein metabolism and reduce the inflammatory response in the body, which also has fewer adverse reactions and higher safety.
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Affiliation(s)
- Guang Dai
- Department of Nephrology, Zhumadian Central Hospital, Zhumadian, Henan 463000, P.R. China
| | - Donghai Wang
- Department of Nephrology, Zhumadian Central Hospital, Zhumadian, Henan 463000, P.R. China
| | - Hua Dong
- Department of Nephrology, The Affiliated Hospital of Binzhou Medical College, Binzhou, Shandong 256603, P.R. China
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23
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Ruan Y, Lam JCW, Zhang X, Lam PKS. Temporal Changes and Stereoisomeric Compositions of 1,2,5,6,9,10-Hexabromocyclododecane and 1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane in Marine Mammals from the South China Sea. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2517-2526. [PMID: 29397695 DOI: 10.1021/acs.est.7b05387] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Stereoisomeric compositions of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) were investigated in the blubber of two species of marine mammals, finless porpoises ( Neophocaena phocaenoides) and Indo-Pacific humpback dolphins ( Sousa chinensis), from the South China Sea between 2005 and 2015. The concentrations of ΣHBCD in samples of porpoise ( n = 59) and dolphin ( n = 32) ranged from 97.2 to 6,260 ng/g lipid weight (lw) and from 447 to 45,800 ng/g lw, respectively, while those of ΣTBECH were both roughly 2 orders of magnitude lower. A significant increasing trend of ΣHBCD was found in dolphin blubber over the past decade. The diastereomeric profiles exhibited an absolute predominance of α-HBCD (mostly >90%), while the proportions of four TBECH diastereomers in the samples appeared similar. A preferential enrichment of the (-)-enantiomers of α-, β-, and γ-HBCD was found in most blubber samples. Interestingly, the body lengths of porpoises showed a significant negative correlation with the enantiomer fractions of α-HBCD. Significant racemic deviations were also observed for α-, γ-, and δ-TBECH enantiomeric pairs. This is the first report of the presence of TBECH enantiomers in the environment. The estimated hazard quotient indicates that there is a potential risk to dolphins due to HBCD exposure.
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Affiliation(s)
- Yuefei Ruan
- State Key Laboratory in Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity , City University of Hong Kong , Hong Kong SAR , China
| | - James C W Lam
- State Key Laboratory in Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity , City University of Hong Kong , Hong Kong SAR , China
- Department of Science and Environmental Studies , The Education University of Hong Kong , Hong Kong SAR , China
| | - Xiaohua Zhang
- Department of Science and Environmental Studies , The Education University of Hong Kong , Hong Kong SAR , China
| | - Paul K S Lam
- State Key Laboratory in Marine Pollution (SKLMP), Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity , City University of Hong Kong , Hong Kong SAR , China
- Department of Chemistry , City University of Hong Kong , Hong Kong SAR , China
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24
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Liu PY, Meng T, Li YY, Cai M, Li XH, Chen J, Qin ZF. Tetrabromoethylcyclohexane affects gonadal differentiation and development in the frog Pelophylax nigromaculatus. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 192:40-47. [PMID: 28917944 DOI: 10.1016/j.aquatox.2017.09.009] [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: 03/04/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
Tetrabromoethylcyclohexane (TBECH), an additive brominated flame retardant, has been shown to have an androgenic activity in vitro. In the present study, we aimed to investigate the effects of TBECH on gonadal differentiation and development in the frog Pelophylax nigromaculatus, an amphibian species sensitive to androgenic chemicals, and to assess the androgenic activity of TBECH in vivo. P. nigromaculatus tadpoles were exposed to TBECH (1, 10, 100nM) from Gosner stage 24 to complete metamorphosis, and to 5α-dihydrotestosterone (DHT) as a positive control. We found that 1nM DHT resulted in 100% males, while the sex ratio in the solvent control group was close to 1:1. In all the TBECH treatment groups, sexually ambiguous gonads based on gross morphology and intersexualities with testicular and ovarian histological structures were found, but no abnormality occurred in the solvent control. In the 1, 10, 100nM TBECH treatment groups, the female percentages were 52%, 31%, 17%, with 36%, 56%, 66% for males and 12%, 13%, 17% for abnormal sexes, respectively. X2-test revealed significant differences in sex ratios between the three TBECH groups and the solvent control group, and the sex ratios in the two higher concentration groups were male-biased. These observations show that TBECH has a masculinizing effect on gonadal differentiation and development in P. nigromaculatus, suggesting an androgenic activity of TBECH in vivo. To our knowledge, this is the first study demonstrating that TBECH could induce gonadal masculinization in an animal, which raises new concerns for reproductive risk of TBECH exposure.
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Affiliation(s)
- Peng-Yan Liu
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei, China
| | - Tan Meng
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yuan-Yuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Man Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xing-Hong Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Juan Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan-Fen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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Nguyen KH, Abou-Elwafa Abdallah M, Moehring T, Harrad S. Biotransformation of the Flame Retardant 1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) in Vitro by Human Liver Microsomes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10511-10518. [PMID: 28846412 DOI: 10.1021/acs.est.7b02834] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The technical mixture of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH or DBE-DBCH) and the pure β-TBECH isomer were subjected to in vitro biotransformation by human liver microsomes (HLM). After 60 min of incubation, 5 potential metabolites of TBECH were identified in microsomal assays of both the TBECH mixture and β-TBECH using ultraperformance liquid chromatography-Q-Exactive Orbitrap mass spectrometry. These include mono- and dihydroxylated TBECH and mono- and dihydroxylated TriBECH as well as an α-oxidation metabolite bromo-(1,2-dibromocyclohexyl)-acetic acid. Our results indicate potential hepatic biotransformation of TBECH via cyctochrome P450-catalyzed hydroxylation, debromination, and α-oxidation. Kinetic studies revealed that the formation of monohydroxy-TBECH, dihydroxy-TBECH, and monohydroxy-TriBECH were best fitted to a Michaelis-Menten enzyme kinetic model. Respective estimated Vmax values (maximum metabolic rate) for these metabolites were 11.8 ± 4, 0.6 ± 0.1, and 10.1 ± 0.8 pmol min-1 mg protein-1 in TBECH mixture and 4992 ± 1340, 14.1 ± 4.9, and 66.1 ± 7.3 pmol min-1 mg protein-1 in β-TBECH. This indicates monohydroxy-TBECH as the major metabolite of TBECH by in vitro HLM-based assay. The estimated in vitro intrinsic clearance (Clint) of TBECH mixture was slower (P < 0.05) than that of pure β-TBECH. While the formation of monohydroxy-TBECH may reduce the bioaccumulation potential and provide a useful biomarker for monitoring TBECH exposure, further studies are required to fully understand the levels and toxicological implications of the identified metabolites.
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Affiliation(s)
- Khanh-Hoang Nguyen
- School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham, B5 2TT United Kingdom
| | - Mohamed Abou-Elwafa Abdallah
- School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham, B5 2TT United Kingdom
- Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University , 71526 Assiut, Egypt
| | - Thomas Moehring
- Thermo Fisher Scientific (GmbH) Bremen , Hanna-Kunath-Strasse 11, 28199 Bremen, Germany
| | - Stuart Harrad
- School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham, B5 2TT United Kingdom
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