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Wang YY, Luo WK, Tang SX, Xiang J, Dang Y, Tang B, Lu QY, Cai FS, Ren MZ, Yu YJ, Zheng J. Bioaccumulation and biotransformation of 1,2-bis (2,4,6-tribromophenoxyethane) (BTBPE) and 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (TBECH) in zebrafish (Danio rerio). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 345:123460. [PMID: 38290655 DOI: 10.1016/j.envpol.2024.123460] [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: 11/17/2023] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 02/01/2024]
Abstract
Despite the increasing production, use, and ubiquitous occurrence of novel brominated flame retardants (NBFRs), little information is available regarding their fate in aquatic organisms. In this study, the bioaccumulation and biotransformation of two typical NBFRs, i.e., 1,2-bis (2,4,6-tribromophenoxyethane) (BTBPE) and 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (TBECH), were investigated in tissues of zebrafish (Danio rerio) being administrated a dose of target chemicals through their diet. Linear accumulation was observed for both BTBPE and TBECH in the muscle, liver, gonads, and brain of zebrafish, and the elimination of BTBPE and TBECH in all tissues followed pseudo-first-order kinetics, with the fastest depuration rate occurring in the liver. BTBPE and TBECH showed low bioaccumulation potential in zebrafish, with biomagnification factors (BMFs) < 1 in all tissues. Individual tissues' function and lipid content are vital factors affecting the distribution of BTBPE and TBECH. Stereoselective accumulation of TBECH enantiomers was observed in zebrafish tissues, with first-eluting enantiomers, i.e. E1-α-TBECH and E1-β-TBECH, preferentially accumulated. Additionally, the transformation products (TPs) in the zebrafish liver were comprehensively screened and identified using high-resolution mass spectrometry. Twelve TPs of BTBPE and eight TPs of TBECH were identified: biotransformation pathways involving ether cleavage, debromination, hydroxylation, and methoxylation reactions for BTBPE and hydroxylation, debromination, and oxidation processes for TBECH. Biotransformation is also a vital factor affecting the bioaccumulation potential of these two NBFRs, and the environmental impacts of NBFR TPs should be further investigated in future studies. The findings of this study provide a scientific basis for an accurate assessment of the ecological and environmental risks of BTBPE and TBECH.
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Affiliation(s)
- Yu-Yu Wang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Wei-Keng Luo
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Song-Xiong Tang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Jun Xiang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Yao Dang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Bin Tang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China.
| | - Qi-Yuan Lu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Feng-Shan Cai
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Ming-Zhong Ren
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Yun-Jiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Jing Zheng
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
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Morel C, Paoli J, Emond C, Debaugnies F, Hardy EM, Creta M, Montagne M, Borde P, Nieuwenhuyse AV, Duca RC, Schroeder H, Grova N. Pharmacokinetic characterisation of a valproate Autism Spectrum Disorder rat model in a context of co-exposure to α-Hexabromocyclododecane. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 105:104343. [PMID: 38122861 DOI: 10.1016/j.etap.2023.104343] [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: 06/16/2023] [Revised: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
Assessing the role of α-hexabromocyclododecane α-HBCDD as a factor of susceptibility for Autism Spectrum disorders by using valproic acid-exposed rat model (VPA) required characterizing VPA pharmacokinetic in the context of α-HBCDD-co-exposure in non-pregnant and pregnant rats. The animals were exposed to α-HBCDD by gavage (100 ng/kg/day) for 12 days. This was followed by a single intraperitoneal dose of VPA (500 mg/kg) or a daily oral dose of VPA (500 mg/kg) for 3 days. Exposure to α-HBCDD did not affect the pharmacokinetics of VPA in pregnant or non-pregnant rats. Surprisingly, VPA administration altered the pharmacokinetics of α-HBCDD. VPA also triggered higher foetal toxicity and lethality with the PO than IP route. α-HBCDD did not aggravate the embryotoxicity observed with VPA, regardless of the route of exposure. Based on this evidence, a single administration of 500 mg/kg IP is the most suitable VPA model to investigate α-HBCDD co-exposure.
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Affiliation(s)
- C Morel
- Calbinotox EA-7488, Faculty of Science and Technology, University of Lorraine, Campus Aiguillettes, B.P. 70239, 54506 Vandœuvre-lès-Nancy, France.
| | - J Paoli
- Calbinotox EA-7488, Faculty of Science and Technology, University of Lorraine, Campus Aiguillettes, B.P. 70239, 54506 Vandœuvre-lès-Nancy, France; UMR Inserm 1256 nGERE, Nutrition-Génétique et exposition aux risques environnementaux, Institute of Medical Research (Pôle BMS) - University of Lorraine, B.P. 184, 54511 Nancy, France.
| | - C Emond
- Calbinotox EA-7488, Faculty of Science and Technology, University of Lorraine, Campus Aiguillettes, B.P. 70239, 54506 Vandœuvre-lès-Nancy, France; PKSH Inc., Crabtree, Quebec, Canada; School of Public Health, DSEST, University of Montreal, Montreal, Quebec, Canada.
| | - F Debaugnies
- Department of Medical Biology, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg.
| | - E M Hardy
- Department of Health Protection, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg.
| | - M Creta
- Department of Health Protection, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg.
| | - M Montagne
- Department of Health Protection, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg.
| | - P Borde
- Department of Medical Biology, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg.
| | - A Van Nieuwenhuyse
- Department of Health Protection, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg; Environment and Health, Department of Public Health and Primary Care, University of Leuven (KU Leuven), Leuven, Belgium.
| | - R C Duca
- Department of Health Protection, National Health Laboratory (LNS), Dudelange, Grand Duchy of Luxembourg; Environment and Health, Department of Public Health and Primary Care, University of Leuven (KU Leuven), Leuven, Belgium.
| | - H Schroeder
- Calbinotox EA-7488, Faculty of Science and Technology, University of Lorraine, Campus Aiguillettes, B.P. 70239, 54506 Vandœuvre-lès-Nancy, France; UMR Inserm 1256 nGERE, Nutrition-Génétique et exposition aux risques environnementaux, Institute of Medical Research (Pôle BMS) - University of Lorraine, B.P. 184, 54511 Nancy, France.
| | - N Grova
- Calbinotox EA-7488, Faculty of Science and Technology, University of Lorraine, Campus Aiguillettes, B.P. 70239, 54506 Vandœuvre-lès-Nancy, France; UMR Inserm 1256 nGERE, Nutrition-Génétique et exposition aux risques environnementaux, Institute of Medical Research (Pôle BMS) - University of Lorraine, B.P. 184, 54511 Nancy, France; Immune Endocrine Epigenetics Research Group, Department of Infection and Immunity-Luxembourg Institute of Health, 29 rue Henri Koch, L-4354, Esch-Sur-Alzette, Grand Duchy of Luxembourg.
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Ma G, Wang Q, Ma K, Chen Y, Lu J, Zhang J, Wang X, Wei X, Yu H. Enantioselective metabolism of novel chiral insecticide Paichongding by human cytochrome P450 3A4: A computational insight. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:122088. [PMID: 37348694 DOI: 10.1016/j.envpol.2023.122088] [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: 05/24/2023] [Revised: 06/17/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
As a novel chiral neonicotinoid insecticide, Paichongding (IPP) has been widely applied in agriculture due to its excellent insecticidal activity. However, the enantioselective metabolism of IPP stereoisomers (5R7R-IPP, 5S7S-IPP, 5R7S-IPP, and 5S7R-IPP) mediated by enzymes in non-target organisms, especially the cytochrome P450s (CYPs), remains unknown. To address this knowledge gap, we developed an integrated computational framework to elucidate the binding interactions and enantioselective metabolism of IPP stereoisomers in human CYP3A4. The results reveal that 5R7R-IPP shows much stronger binding affinity to CYP3A4 than 5S7S-IPP, while enantiomers 5R7S-IPP and 5S7R-IPP have no essential difference in their binding potential, owing to their specific interactions with key CYP3A4 residues. Although enantiomers 5R7R-IPP and 5S7S-IPP feature distinct binding modes resulting from the chiral differences, their transformation activities are slightly different, with C5 and C13 being the primary metabolic sites, respectively. In contrast, CYP3A4 preferably metabolizes 5R7S-IPP over 5S7R-IPP. The metabolism of epimers 5R7R-IPP and 5R7S-IPP share C5-hydroxylation routes due to the conserved 5R-conformaitons, but differ with the transformation routes at C11/C13 and C3 sites. The 7R-chirality of 5S7R-IPP significantly reduces the metabolic potency compared to 5S7S-IPP. CYP3A4-catalyzed hydroxylation and desaturation of IPP stereoisomers generate various chiral metabolites, with C5- and C13-hydroxyIPPs further transforming into depropylated products. Furthermore, the toxicity assessment reveals that IPP, along with the majority of its hydroxylated, desaturated, and depropylated metabolites, can potentially induce adverse effects on human health, specifically hepatotoxicity, respiratory toxicity, and carcinogenicity. This study provides valuable insights into the enantioselective fate of chiral IPP metabolism by CYP3A4, and the identified metabolites can serve as potential biomarkers for monitoring IPP exposure and associated health risk in human body.
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Affiliation(s)
- Guangcai Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Qiuyi Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Kan Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Yewen Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Jiayu Lu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Jing Zhang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Xueyu Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, 321004, Jinhua, China.
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Huang X, Xu K, Lyu L, Ding C, Zhao Y, Wang X. Identification and yield of metabolites of chlorinated paraffins incubated with chicken liver microsomes: Assessment of their potential to convert into metabolites. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131640. [PMID: 37201278 DOI: 10.1016/j.jhazmat.2023.131640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/20/2023]
Abstract
Chlorinated paraffins (CPs) are emerging environmental pollutants. Although metabolism has been shown to affect the differential accumulation of short-chain (SCCPs), medium-chain (MCCPs) and long-chain (LCCPs) CPs in birds, CP metabolites have rarely been reported and the extent to which they are formed is still unclear. In this study, single and mixed CP standards were incubated with chicken liver microsomes in vitro to study the generation of CP metabolites. Putative aldehyde/ketone and carboxylic acid metabolites identified by mass spectroscopy data were shown to be false positive results. Phase I metabolism of CPs first formed monohydroxylated ([M-Cl+OH]) and then dihydroxylated ([M-2Cl+2OH]) products. The yields of monohydroxylated metabolites of CPs decreased with increasing carbon chain length and chlorine content at the initial stage of reaction. Notably, the yield of monohydroxylated metabolites of SCCPs with 51.5% Cl content reached 21%, and that of 1,2,5,6,9,10-hexachlorodecane (C10H16Cl6) was as high as 71%. Thus, monohydroxy metabolites of CPs in birds should not be ignored, especially those of SCCPs. This study provides important data that could support improvements to the ecological/health risk assessment of CPs.
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Affiliation(s)
- Xiaomei Huang
- Institute of Quality Standard and Monitoring Technology for Agro-Products, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China; Laboratory of Quality & Safety Risk Assessment for Agro-Products (Guangzhou), Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
| | - Kaihang Xu
- Institute of Quality Standard and Monitoring Technology for Agro-Products, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China; Laboratory of Quality & Safety Risk Assessment for Agro-Products (Guangzhou), Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
| | - Lina Lyu
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Chenhong Ding
- Institute of Quality Standard and Monitoring Technology for Agro-Products, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Yarong Zhao
- Institute of Quality Standard and Monitoring Technology for Agro-Products, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China; Laboratory of Quality & Safety Risk Assessment for Agro-Products (Guangzhou), Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
| | - Xu Wang
- Institute of Quality Standard and Monitoring Technology for Agro-Products, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China; Laboratory of Quality & Safety Risk Assessment for Agro-Products (Guangzhou), Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China.
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Marques ML, Cairrao E. Occurrence and Health Effects of Hexabromocyclododecane: An Updated Review. TOXICS 2023; 11:toxics11050409. [PMID: 37235223 DOI: 10.3390/toxics11050409] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/17/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023]
Abstract
Hexabromocyclododecane (HBCD) is a non-aromatic compound belonging to the bromine flame retardant family and is a known persistent organic pollutant (POP). This compound accumulates easily in the environment and has a high half-life in water. With a variety of uses, the HBCD is found in house dust, electronics, insulation, and construction. There are several isomers and the most studied are α-, β-, and γ-HBCD. Initially used as a substitute for other flame retardants, the polybrominated diphenyl ethers (PBDEs), the discovery of its role as a POP made HBCD use and manufacturing restricted in Europe and other countries. The adverse effects on the environment and human health have been piling, either as a result from its accumulation or considering its power as an endocrine disruptor (ED). Furthermore, it has also been proven that it has detrimental effects on the neuronal system, endocrine system, cardiovascular system, liver, and the reproductive system. HBCD has also been linked to cytokine production, DNA damage, increased cell apoptosis, increased oxidative stress, and reactive oxygen species (ROS) production. Therefore, this review aims to compile the most recent studies regarding the negative effects of this compound on the environment and human health, describing the possible mechanisms by which this compound acts and its possible toxic effects.
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Affiliation(s)
- Maria Lopes Marques
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal
| | - Elisa Cairrao
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506 Covilhã, Portugal
- FCS-UBI, Faculty of Health Sciences, University of Beira Interior, 6200-506 Covilhã, Portugal
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Proença S, van Sabben N, Legler J, Kamstra JH, Kramer NI. The effects of hexabromocyclododecane on the transcriptome and hepatic enzyme activity in three human HepaRG-based models. Toxicology 2023; 485:153411. [PMID: 36572169 DOI: 10.1016/j.tox.2022.153411] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/09/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
The disruption of thyroid hormone homeostasis by hexabromocyclododecane (HBCD) in rodents is hypothesized to be due to HBCD increasing the hepatic clearance of thyroxine (T4). The extent to which these effects are relevant to humans is unclear. To evaluate HBCD effects on humans, the activation of key hepatic nuclear receptors and the consequent disruption of thyroid hormone homeostasis were studied in different human hepatic cell models. The hepatoma cell line, HepaRG, cultured as two-dimensional (2D), sandwich (SW) and spheroid (3D) cultures, and primary human hepatocytes (PHH) cultured as sandwich were exposed to 1 and 10 µM HBCD and characterized for their transcriptome changes. Pathway enrichment analysis showed that 3D models, followed by SW, had a stronger transcriptome response to HBCD, which is explained by the higher expression of hepatic nuclear receptors but also greater accumulation of HBCD measured inside cells in these models. The Pregnane X receptor pathway is one of the pathways most upregulated across the three hepatic models, followed by the constitutive androstane receptor and general hepatic nuclear receptors pathways. Lipid metabolism pathways had a downregulation tendency in all exposures and in both PHH and the three cultivation modes of HepaRG. The activity of enzymes related to PXR/CAR induction and T4 metabolism were evaluated in the three different types of HepaRG cultures exposed to HBCD for 48 h. Reference inducers, rifampicin and PCB-153 did affect 2D and SW HepaRG cultures' enzymatic activity but not 3D. HBCD did not induce the activity of any of the studied enzymes in any of the cell models and culture methods. This study illustrates that for nuclear receptor-mediated T4 disruption, transcriptome changes might not be indicative of an actual adverse effect. Clarification of the reasons for the lack of translation is essential to evaluate new chemicals' potential to be thyroid hormone disruptors by altering thyroid hormone metabolism.
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Affiliation(s)
- Susana Proença
- Department of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands; Toxicology Division, Wageningen University, Wageningen, the Netherlands.
| | - Nick van Sabben
- Department of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Juliette Legler
- Department of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Jorke H Kamstra
- Department of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Nynke I Kramer
- Department of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands; Toxicology Division, Wageningen University, Wageningen, the Netherlands
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Malala Irugal Bandaralage S, Ignacio Bertucci J, Park B, Green D, Brinkmann M, Masse A, Crump D, Basu N, Hogan N, Hecker M. Maternal Transfer and Apical and Physiological Effects of Dietary Hexabromocyclododecane Exposure in Parental Fathead Minnows (Pimephales promelas). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:143-153. [PMID: 36282020 DOI: 10.1002/etc.5506] [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: 04/22/2022] [Revised: 06/22/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Hexabromocyclododecane (HBCD) is a persistent organic pollutant that has been characterized as an endocrine disruptor, undergoes maternal transfer, and hinders development and growth in oviparous organisms. The present study examined the apical effects of dietary HBCD (11.5, 36.4, 106 mg/kg, wet wt) on adult fathead minnow exposed for 49 days and the subsequent accumulation and maternal transfer kinetics in adult tissue and eggs, respectively. Exposed adults displayed a significant increase in egg production in the medium treatment group, but no other significant effects were noted. Maternal transfer of dietary HBCD had a similar egg-to-muscle ratios (EMR) in the low and medium treatment groups (1.65 and 1.27 [wet wt], respectively). However, the high treatment group deviated from other treatments with an EMR of 4.2 (wet wt), potentially due to differences in total lipid content in food and/or reaching diffusion/lipid saturation limits in adult tissue, resulting in lower accumulation in the adult muscle tissue. A positive correlation was observed between egg HBCD concentration and time of exposure, which indicates that maternal transfer of HBCD is of concern in fish, and further studies should be conducted to fully elucidate the potential adverse effects that may be observed in the early life stage of oviparous organisms. Environ Toxicol Chem 2023;42:143-153. © 2022 SETAC.
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Affiliation(s)
- Susari Malala Irugal Bandaralage
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Spanish Institute of Oceanography, Oceanographic Centre of Vigo, Vigo, Spain
| | - Juan Ignacio Bertucci
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Spanish Institute of Oceanography, Oceanographic Centre of Vigo, Vigo, Spain
| | - Brad Park
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Derek Green
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Markus Brinkmann
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- School of the Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Anita Masse
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Doug Crump
- National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, Ontario, Canada
| | - Niladri Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada
| | - Natacha Hogan
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- School of the Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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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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Hexabromocyclododecanes Are Dehalogenated by CYP168A1 from Pseudomonas aeruginosa Strain HS9. Appl Environ Microbiol 2021; 87:e0082621. [PMID: 34132585 DOI: 10.1128/aem.00826-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hexabromocyclododecanes (HBCDs) are widely used brominated flame retardants that cause antidiuretic hormone syndrome and even induce cancer. However, little information is available about the degradation mechanisms of HBCDs. In this study, genomic and proteomic analyses, reverse transcription-quantitative PCR, and gene knockout assays reveal that a cytochrome P450-encoding gene is responsible for HBCD catabolism in Pseudomonas aeruginosa HS9. The CO difference spectrum of the enzyme CYP168A1 was matched to P450 characteristics via UV visibility. We demonstrate that the reactions of debromination and hydrogenation are carried out one after another based on detection of the metabolites pentabromocyclododecanols (PBCDOHs), tetrabromocyclododecadiols (TBCDDOHs), and bromide ion. In the 18O isotope experiments, PBCD18OHs were only detected in the H218O group, proving that the added oxygen is derived from H2O, not from O2. This study elucidates the degradation mechanism of HBCDs by Pseudomonas. IMPORTANCE Hexabromocyclododecanes (HBCDs) are environmental pollutants that are widely used in industry. In this study, we identified and characterized a novel key dehalogenase, CYP168A1, that is responsible for HBCD degradation from Pseudomonas aeruginosa strain HS9. This study provides new insights into understanding biodegradation of HBCDs.
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Zhang R, Li P, Zhang R, Shi X, Li Y, Zhang Q, Wang W. Computational study on the detoxifying mechanism of DDT metabolized by cytochrome P450 enzymes. JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125457. [PMID: 33652222 DOI: 10.1016/j.jhazmat.2021.125457] [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: 01/19/2021] [Revised: 02/06/2021] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Predicting the detoxifying mechanism and potential toxic derivatives of xenobiotic substances is significant for risk assessment. The present study delineated the detoxifying mechanism of 1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (DDT) metabolized by human P450 enzymes using a combination of molecular dynamic (MD), quantum mechanics/molecular mechanics (QM/MM) and density functional theory (DFT). This study highlights that DDT can be metabolized by P450 enzymes through the hydrogen abstraction and electrophilic addition mechanism, and the main derivatives are epoxides (2,3-oxide-DDT and 3,4-oxide-DDT), DDE and dicofol. The epoxides are unstable and the C-O bond cleavage easily occurs by the reaction with hydronium ion or hydroxyl radicals, yielding endocrine disruptor hydroxylated DDT. The eco-toxicity evaluation indicates that the derivatives of DDT are less toxic than DDT, and the solubility increase of the derivatives can accelerate their excretion from the body. The study can provide an understanding of the biotransformation of DDT by the P450 enzymes in human livers.
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Affiliation(s)
- Ruiming Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Pengfei Li
- Shandong Academy for Environmental Planning, Jinan 250014, PR China
| | - Ruiying Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Xiangli Shi
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China
| | - Yanwei Li
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China.
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
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11
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Wang XS, Tan X, Zhang Y, Hu XX, Shen C, Huang YY, Fu HL, Yu RH, He CT. The enantiomer-selective metabolism of hexabromocyclododecanes (HBCDs) by human HepG2 cells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144430. [PMID: 33736337 DOI: 10.1016/j.scitotenv.2020.144430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Although hepatic metabolism of hexabromocyclododecanes (HBCDs) played critical roles in the selective bioaccumulation of HBCDs in humans, the hepatic metabolism patterns of its enantiomers remained ambiguous. Aiming to elucidate the mechanism on hepatic metabolism of hexabromocyclododecanes (HBCDs) enantiomers, the enantiomers ((+)-α-HBCD, (-)-α-HBCD, (+)-γ-HBCD, and (-)-γ-HBCD), the diastereoisomers (α-, β-, and γ-HBCDs) and the mixed of α- and γ-HBCDs were incubated with human HepG2 cell under different exposure levels in the present study. The clearance percentages ranked as γ-HBCD enantiomers >β-HBCD enantiomers >α-HBCD enantiomers at the same exposure levels. The clearance percentages of (+)- and (-)-α-HBCDs increased when cells were exposed to racemic α-HBCD and the mixture of racemic α- and γ-HBCDs (p < 0.05). (-)-γ-HBCD was more resistant to human hepatic metabolism than (+)-γ-HBCD, leading to the enantiomer fractions (EFs) of γ-HBCD lower than 0.50. (-)-α-HBCD was slightly more metabolized when independently exposed to α-HBCD, while (+)-α-HBCD was more preferentially metabolized after exposure to α- and γ-HBCD mixtures. Hydroxylation and debromination HBCD metabolites were identified. In addition, the different EFs of HBCDs in cells and mediums suggested the selective transfer of chiral HBCDs and HBCD metabolites through the cell membrane. This study provided new insight into the enantiomer-selective metabolism of HBCDs.
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Affiliation(s)
- Xue-Song Wang
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, China National Analytical Center Guangzhou (Guangdong Institute of Analysis), Guangdong Academy of Sciences, 100 Xianlie Middle Road, Guangzhou 510070, China
| | - Xiao Tan
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China
| | - Yan Zhang
- School of Life Science, Sun Yat-sen University, Guangzhou 510275, China
| | - Xia-Xin Hu
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China
| | - Chuang Shen
- School of Safety and Environmental Engineering, Hunan Institute of Technology, Hengyang 421002, China
| | - Ying-Ying Huang
- School of Safety and Environmental Engineering, Hunan Institute of Technology, Hengyang 421002, China
| | - Hui-Ling Fu
- School of Safety and Environmental Engineering, Hunan Institute of Technology, Hengyang 421002, China
| | - Ruo-Han Yu
- School of Life Science, Sun Yat-sen University, Guangzhou 510275, China
| | - Chun-Tao He
- School of Agriculture, Sun Yat-sen University, Guangzhou 510275, China.
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12
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Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L(R, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Wallace H, Benford D, Fürst P, Rose M, Ioannidou S, Nikolič M, Bordajandi LR, Vleminckx C. Update of the risk assessment of hexabromocyclododecanes (HBCDDs) in food. EFSA J 2021; 19:e06421. [PMID: 33732387 PMCID: PMC7938899 DOI: 10.2903/j.efsa.2021.6421] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The European Commission asked EFSA to update its 2011 risk assessment on hexabromocyclododecanes (HBCDDs) in food. HBCDDs, predominantly mixtures of the stereoisomers α-, β- and γ-HBCDD, were widely used additive flame retardants. Concern has been raised because of the occurrence of HBCDDs in the environment, food and in humans. Main targets for toxicity are neurodevelopment, the liver, thyroid hormone homeostasis and the reproductive and immune systems. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour in mice can be considered the critical effects. Based on effects on spontaneous behaviour in mice, the Panel identified a lowest observed adverse effect level (LOAEL) of 0.9 mg/kg body weight (bw) as the Reference Point, corresponding to a body burden of 0.75 mg/kg bw. The chronic intake that would lead to the same body burden in humans was calculated to be 2.35 μg/kg bw per day. The derivation of a health-based guidance value (HBGV) was not considered appropriate. Instead, the margin of exposure (MOE) approach was applied to assess possible health concerns. Over 6,000 analytical results for HBCDDs in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary LB exposure to HBCDDs were fish meat, eggs, livestock meat and poultry. The CONTAM Panel concluded that the resulting MOE values support the conclusion that current dietary exposure to HBCDDs across European countries does not raise a health concern. An exception is breastfed infants with high milk consumption, for which the lowest MOE values may raise a health concern.
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13
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Hu L, Luo D, Wang L, Yu M, Zhao S, Wang Y, Mei S, Zhang G. Levels and profiles of persistent organic pollutants in breast milk in China and their potential health risks to breastfed infants: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:142028. [PMID: 32906049 DOI: 10.1016/j.scitotenv.2020.142028] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Although some persistent organic pollutants (POPs) were prohibited or limited in use several decades ago, they are still frequently detected in the human body. The purpose of this study was to understand the levels and profiles of POPs in breast milk in China and assess their potential health risks among breastfed infants under six months of age. A literature review focused on China was performed for studies published from 2001 to 2020. The POP levels in breast milk along with other important variables were extracted, and then the average individual POP levels in breast milk were estimated. This review summarises the distribution of traditional and new POPs, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), legacy brominated flame retardants (BFRs), perfluorinated compounds (PFCs), and chlorinated paraffins (CPs) and reported notably high levels of short-chain chlorinated paraffins and 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) in breast milk. Although the levels of traditional POPs generally declined over time, especially p,p'-DDE and beta-hexachlorocyclohexane (β-HCH), women living in coastal areas, urban areas, and southern China still have a high body burden of certain POPs. In the present study, the estimated daily intake (EDI) of POPs through breastfeeding was used to evaluate the health risk for infants by comparing with acceptable levels. The findings suggested that infants born in coastal areas most likely suffered potential health risk from exposure to DDT, and the health risk of hexachlorobenzene (HCB) in infants in most nationwide regions remains a concern. More importantly, the EDI of PCBs for infants exceeds the safe limit on a national scale. Continuous surveillance of PCBs in breast milk is critical to evaluate the potential health effects on humans.
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Affiliation(s)
- Liqin Hu
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei 430030, China
| | - Dan Luo
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei 430030, China
| | - Limei Wang
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei 430030, China
| | - Meng Yu
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei 430030, China
| | - Shizhen Zhao
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Youjie Wang
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei 430030, China; Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Surong Mei
- State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei 430030, China.
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
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14
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Li H, Zhang Z, Sun Y, Wang W, Xie J, Xie C, Hu Y, Gao Y, Xu X, Luo X, Mai B. Tetrabromobisphenol A and hexabromocyclododecanes in sediments and biota from two typical mangrove wetlands of South China: Distribution, bioaccumulation and biomagnification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:141695. [PMID: 32861076 DOI: 10.1016/j.scitotenv.2020.141695] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 06/11/2023]
Abstract
Tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) were examined in sediments and biota species from two mangrove wetlands of the Pearl River Estuary (PRE) and the Jiulong River Estuary (JRE), South China, to investigate their distribution, bioaccumulation and biomagnification in mangrove food webs. Levels of TBBPA and ΣHBCD (sum of α-, β- and γ-HBCDs) ranged from 0.003 to 0.31 and not detected (nd) to 1.11 ng/g dry weight in the sediments, and from 0.56 to 22.1 and nd to 56.3 ng/g lipid weight in the biota species, respectively. γ-HBCD was the major diastereoisomer in the PRE sediments, while α- and γ-HBCDs predominated in the JRE sediments. In contrast, α-HBCD was dominant in the biota. Mean enantiomeric fractions (EFs) of α-, β- and γ-HBCDs in the sediments all followed the trend of JRE > racemic standard > PRE. A significant enrichment of (-)-α-HBCD was found in the biota (p = 0.04), with EFs in the range of 0.297-0.485. Bioaccumulations were seen for TBBPA and α-HBCD as their biota-sediment accumulation factors (BSAFs) were greater than 1. (-)-α-HBCD had significantly greater BSAFs than (+)-α-HBCD (p = 0.04), indicating the preferential bioaccumulation of (-)-α-HBCD. Biomagnification factors (BMFs) of TBBPA ranged from 0.83 to 1.51, which varied among feeding relationships and mangroves. Positive relationships were found between TBBPA concentrations and trophic levels of the biota species with trophic magnification factors of 2.17 for the PRE and 1.22 for the JRE, suggesting that TBBPA biomagnifies in the mangrove food webs. No biomagnifications were observed for ΣHBCD, α-HBCD and its enantiomers.
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Affiliation(s)
- Huawei Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zaiwang Zhang
- Shandong Engineering and Technology Research Center for Ecological Fragile Belt of Yellow River Delta, Binzhou University, Binzhou 256600, China
| | - Yuxin Sun
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China.
| | - Weiwei Wang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinli Xie
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenmin Xie
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongxia Hu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yongli Gao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiangrong Xu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Xiaojun Luo
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Bixian Mai
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
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15
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Wang J, Li J, Shi Z. Dietary exposure assessment of a nursing mother-infant cohort to legacy and novel brominated flame retardants: Results of a 3-day duplicate diet study in Beijing, China. CHEMOSPHERE 2020; 254:126843. [PMID: 32339796 DOI: 10.1016/j.chemosphere.2020.126843] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
In a 3-day duplicate diet study of a nursing mother-infant cohort (n = 20), the levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and 5 novel brominated flame retardants (BFRs) were measured in 60 24-h duplicate diet samples and 20 breast milk samples provided by the mothers. The dietary BFR intake and related health risks of the mothers and their babies due to food consumption or human milk ingestion were subsequently assessed. At median concentrations of 284, 264 and 177 pg/g wet weight (ww) in the diet, decabrominated diphenyl ethers (BDE-209), decabromodiphenyl ethane (DBDPE) and HBCDD were predominant among the total BFRs. In human milk, HBCDD was the most abundant BFR, followed by BDE-209 and DBDPE, which indicates that BDE-209 and HBCDD have remained ubiquitous in the environment because of their continuous production and use in China. Meanwhile, concentrations of DBDPE were comparative to those of PBDEs and HBCDD in both diet and human milk, and DBDPE also had much higher concentrations than any other NBFRs, which indicates that the BFR consumption pattern in China is shifting from legacy BFRs to NBFRs. The median estimated dietary intakes (EDIs) of BDE-209, HBCDD and DBDPE for the mothers were 6.83, 3.73 and 5.44 ng/kg bw/day, respectively, and EDIs for their nursing babies were 24.7, 41.9 and 7.83 ng/kg bw/day, respectively. The nursing infants showed higher BFR body burden than the mothers. However, the EDIs obtained for both mothers and their babies discloses a low health risk to this mother-infant cohort.
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Affiliation(s)
- Jiandi Wang
- Shunyi Maternal and Children's Hospital of Beijing Children's Hospital, Capital Medical University, Beijing, 110113, China; School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Jian Li
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China; Dongcheng District Administration Center of Community Health Service, Beijing, 100010, China
| | - Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China.
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16
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Ma G, Yu H, Han C, Jia Y, Wei X, Wang Z. Binding and Metabolism of Brominated Flame Retardant β-1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane in Human Microsomal P450 Enzymes: Insights from Computational Studies. Chem Res Toxicol 2020; 33:1487-1496. [DOI: 10.1021/acs.chemrestox.0c00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Guangcai Ma
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Cenyang Han
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Yue Jia
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Zhiguo Wang
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, China
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17
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Huang M, Li J, Xiao Z, Shi Z. Tetrabromobisphenol A and hexabromocyclododecane isomers in breast milk from the general population in Beijing, China: Contamination levels, temporal trends, nursing infant's daily intake, and risk assessment. CHEMOSPHERE 2020; 244:125524. [PMID: 31812044 DOI: 10.1016/j.chemosphere.2019.125524] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/26/2019] [Accepted: 11/29/2019] [Indexed: 05/27/2023]
Abstract
Two currently used brominated flame retardants (BFRs), α, β, γ-hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA), were measured in 111 breast milk samples from 37 Beijing mothers. Each mother provided one milk sample per month for 3 months. HBCDD was detected in almost all samples, and the median level reached 5.67 ng g-1 lipid weight (lw). α- HBCDD was the most abundant isomer (median: 4.23 ng g-1 lw), followed by γ- and β-HBCDD. For TBBPA, a relatively lower detecting frequency (64%) and contamination level (median: 1.57 ng g-1 lw) were obtained. A comparison to our previous study revealed that the occurrence of TBBPA and HBCDD in Beijing human milk significantly rose from 2011 to 2014, whereas another commonly used class of BFRs, polybrominated diphenyl ethers (PBDEs), showed significantly decreased during this period. However, a comparison among currently used BFRs showed that levels of some BFRs, such as HBCDD, surpassed those of PBDEs, which indicated that PBDEs were no longer the primarily used BFR in China. However, no significant temporal trends for BFR levels were observed over the 3 months of lactation. Daily intakes of TBBPA and HBCDD were calculated for nursing infants and the median TBBPA and HBCDD intakes via breastfeeding were 6.62 and 26.4 ng kg-1 bw day-1, respectively. These values were several times higher than those for adults via food consumption. However, risk assessment using the margin of exposure approach indicated that intakes of TBBPA and HBCDD via breastfeeding can scarcely cause significant health risks to infants.
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Affiliation(s)
- Morong Huang
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Jian Li
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China; Dongcheng District Administration Center of Community Health Service, Beijing 100010, China
| | - Zhongxin Xiao
- Core Facility Center, Capital Medical University, Beijing 100069, China
| | - Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China.
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18
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Li B, Lan Z, Wang L, Sun H, Yao Y, Zhang K, Zhu L. The release and earthworm bioaccumulation of endogenous hexabromocyclododecanes (HBCDDs) from expanded polystyrene foam microparticles. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113163. [PMID: 31542672 DOI: 10.1016/j.envpol.2019.113163] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/29/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Hexabromocyclododecanes (HBCDDs) are common chemical additives in expanded polystyrene foam (EPS). To evaluate the bioaccumulation potential of endogenous HBCDDs in EPS microparticles by earthworms, two ecologically different species of earthworms (Eisenia fetida and Metaphire guillelmi) were exposed to soil added with EPS microparticles of different particle sizes (EPS2000, 830-2000 μm and EPS830, <830 μm). To clarify the accumulation mechanisms, leaching experiments using EPS microparticles in different solutions were conducted. After exposure to EPS microparticles-amended soils (S-EPS) for 28 d, the total concentrations of HBCDDs reached 307-371 ng g-1 dw in E. fetida and 90-133 ng g-1 dw in M. guillelmi, which were higher than those in earthworms exposed to the soil that was artificially contaminated with a similar level of HBCDDs directly (ACS). The accumulation of HBCDDs in earthworms was significantly influenced by EPS microparticles' size and earthworms' species. The total concentrations of HBCDDs in earthworms' cast were significantly higher than the theoretical concentration of HBCDDs in S-EPS, which suggested that EPS microparticles can be ingested by earthworms. The release rate of HBCDDs from EPS5000 (2000-5000 μm) into water-based solutions (<1%) after a 3.5-h incubation was far lower than that into earthworm digestive fluid (7%). These results illustrated that the ingestion of EPS microparticles and consequent solubilization of HBCDDs by digestive fluid play an important role in the accumulation of HBCDDs contained in EPS microparticles in earthworms. After a 28-d incubation with the soil solution, 4.9% of the HBCDDs was accumulatively leached from the EPS5000, which indicated that HBCDDs can be released from EPS microparticles to soil environment, and then accumulated by earthworms. Moreover, similar to those exposed to ACS, the diastereoisomer- and enantiomer-specific accumulation of HBCDDs in earthworms occurred when exposed to S-EPS. This study provides more evidence for the risk of microplastics to the soil ecosystem.
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Affiliation(s)
- Bing Li
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China; National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, Taian, 271018, China
| | - Zhonghui Lan
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Lei Wang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Hongwen Sun
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
| | - Yiming Yao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Kai Zhang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Lusheng Zhu
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Key Laboratory of Agricultural Environment in Universities of Shandong, College of Resources and Environment, Shandong Agricultural University, Taian, 271018, China
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19
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Shi X, Zha J, Wen B, Zhang S. Diastereoisomer-specific neurotoxicity of hexabromocyclododecane in human SH-SY5Y neuroblastoma cells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 686:893-902. [PMID: 31200309 DOI: 10.1016/j.scitotenv.2019.06.008] [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: 03/22/2019] [Revised: 05/29/2019] [Accepted: 06/01/2019] [Indexed: 06/09/2023]
Abstract
Hexabromocyclododecane (HBCD) is a widely applied brominated flame retardant (BFR) and is regarded as a persistent organic pollutant. It has been found in human tissues and has the potential to cause neurological disorders. However, our understanding of HBCD neurotoxicity at the diastereoisomer level remains lacking. Here, we investigated the neurotoxicity of three HBCD diastereoisomers, i.e., α-, β-, and γ-HBCD, in SH-SY5Y human neuroblastoma cells. Results showed that the HBCD diastereoisomers decreased cell viability, increased lactate dehydrogenase (LDH) release, and impaired cytoskeleton development. Typical morphological features and apoptosis rates showed that the HBCD diastereoisomers induced SH-SY5Y cell apoptosis. The expression levels of several cell apoptosis-related genes and proteins, including Bax, caspase-3, caspase-9, cytochrome c, Bcl-2, and X-linked inhibitor of apoptosis (XIAP), as well as the cell cycle arrest, DNA damage, adenosine triphosphate (ATP) consumption, reactive oxygen species (ROS) levels, and intracellular calcium ion (Ca2+) levels, were examined. Results showed that the HBCD diastereoisomer neurotoxicity was ranked β-HBCD > γ-HBCD > α-HBCD. The cell apoptosis and caspase expression levels of the three HBCD diastereoisomers followed the same order, suggesting that caspase-dependent apoptosis may be one mechanism responsible for the structure-selective HBCD diastereoisomer neurotoxicity. The levels of intracellular Ca2+ and ROS increased significantly. The ROS levels were ordered β-HBCD > γ-HBCD > α-HBCD, whereas those of intracellular Ca2+ were γ-HBCD > β-HBCD > α-HBCD. Thus, ROS may be a key factor regulating the neurotoxicity of HBCD diastereoisomers. To the best of our knowledge, this is the first study to report on the diastereoisomer-specific toxicity of HBCD in human neural cells and on the possible mechanisms responsible for the selective neurotoxicity of HBCD diastereoisomers.
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Affiliation(s)
- Xiaoli Shi
- 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
| | - Jinmiao Zha
- 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
| | - Bei Wen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Shuzhen Zhang
- 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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Zhang Z, Gao B, He Z, Li L, Shi H, Wang M. Enantioselective metabolism of four chiral triazole fungicides in rat liver microsomes. CHEMOSPHERE 2019; 224:77-84. [PMID: 30818197 DOI: 10.1016/j.chemosphere.2019.02.119] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/18/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Triazole fungicides with one or two chiral centers are widely used worldwide. The liver microsomes plays a major role in the metabolism and systemic elimination of chiral pesticides after exposure. In this present work, enantioselective metabolism of four representative chiral triazole fungicides (prothioconazole, flutriafol, triticonazole, and epoxiconazole) in rat liver microsomes (RLM) was investigated using LC-MS/MS. Baseline separation of the four chiral fungicides and prothioconazole-desthio was achieved on Lux-cellulose-1. The results demonstrated that the R-enantiomers of flutriafol and triticonazole were preferentially metabolized with half-life ranged from 17.33 min to 99.00 min. The R,S-epoxiconazole accumulated with a half-life of 173.25 min. There was no stereoselectivity for prothioconazole. However, remarkable stereoselective metabolism was observed for prothioconazole-desthio. The results of enzyme kinetic revealed different affinities between the enantiomers and metabolic enzymes. In addition, homologous modeling and molecular docking results indicated that enantioselectivity were partially to enantiospecific binding affinities with CYP enzymes. This study highlights a new quantitative approach for stereoselective metabolism of chiral agrochemicals and provides more accurate data on risk assessment of triazole fungicides.
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Affiliation(s)
- Zhaoxian Zhang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Ministry of Education, Nanjing, 210095, PR China
| | - Beibei Gao
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Ministry of Education, Nanjing, 210095, PR China
| | - Zongzhe He
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Ministry of Education, Nanjing, 210095, PR China
| | - Lianshan Li
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Ministry of Education, Nanjing, 210095, PR China
| | - Haiyan Shi
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Ministry of Education, Nanjing, 210095, PR China
| | - Minghua Wang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Ministry of Education, Nanjing, 210095, PR China.
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Gao B, Zhao S, Zhang Z, Li L, Hu K, Kaziem AE, He Z, Hua X, Shi H, Wang M. A potential biomarker of isofenphos-methyl in humans: A chiral view. ENVIRONMENT INTERNATIONAL 2019; 127:694-703. [PMID: 30991225 DOI: 10.1016/j.envint.2019.04.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/28/2019] [Accepted: 04/06/2019] [Indexed: 06/09/2023]
Abstract
Isofenphos-methyl (IFP) is a very active and persistent chiral insecticide. However, IFP has lower activity against acetylcholinesterases (AChEs). Previously, it was confirmed that phosphorothioate organophosphorus pesticides with N-alkyl (POPN) require activation by oxidative desulfuration and N-dealkylation. In this work, we demonstrated that IFP could be metabolized in human liver microsomes to isofenphos-methyl oxon (IFPO, 52.7%), isocarbophos (ICP, 14.2%) and isocarbophos oxon (ICPO, 11.2%). It was found that (R)-IFP was preferentially degraded compared to the (S)-enantiomer, and the enantiomeric fraction (EF) value reached 0.61 at 60 min. However, (S)-enantiomers of the three metabolites, were degraded preferentially, and the EF values ranged from 0.34 to 0.45. Cytochrome P450 (CYP) isoforms CYP3A4, CYP2E1, and CYP1A2 and carboxylesterase enzyme have an essential role in the enantioselective metabolism of IFP; but, the enzymes that participate in the degradation of IFP metabolites are different. The AChE inhibition bioassay indicated that ICPO is the only effective inhibitor of AChE. The covalent molecular docking has proposed that the metabolites of IFP and its analogs after N-dealkylation and oxidative desulfuration will possess the highest inhibitory activity against AChE. This study is the first to demonstrate that ICPO can be regarded as a potential biomarker for the biomonitoring of IFP and ICP exposure in humans.
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Affiliation(s)
- Beibei Gao
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Shuangshuang Zhao
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Zhaoxian Zhang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Lianshan Li
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Kunming Hu
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Amir E Kaziem
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China; Department of Environmental Agricultural Science, Institute of Environmental Studies and Research, Ain Shams University. Cairo11566, Egypt
| | - Zongzhe He
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Xiude Hua
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Haiyan Shi
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China
| | - Minghua Wang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China.
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Wang J, Zhao X, Wang Y, Shi Z. Tetrabromobisphenol A, hexabromocyclododecane isomers and polybrominated diphenyl ethers in foodstuffs from Beijing, China: Contamination levels, dietary exposure and risk assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 666:812-820. [PMID: 30818205 DOI: 10.1016/j.scitotenv.2019.02.324] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/16/2019] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
Hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and polybrominated diphenyl ether (PBDEs) are three legacy brominated flame retardants (BFRs); however, they are still produced and used in China. In this study, these three BFRs were measured in commonly consumed animal-based and plant-based foodstuffs from Beijing, China, and the dietary intakes of these BFRs by adults in Beijing were estimated to assess the related health concerns. The median levels of TBBPA in animal-based foodstuffs ranged from <LOD to 8.03 ng/g lipid weight (lw), whereas those in all the plant-based food groups were lower than the LOD. The median levels of total HBCD in animal-based foodstuffs were from 1.14 to 5.65 ng/g lw, and α-HBCD was the predominant isomer. The median HBCD level in vegetables was 0.266 ng/g wet weight (ww), whereas γ-HBCD was the most abundant isomer. The median levels of total PBDEs in animal-based foodstuffs were from 3.22 to 13.7 ng/g lw, and BDE-209 was the most abundant congener, comprising a proportion of at least 85% of total PBDEs. The daily dietary intakes of TBBPA, HBCD and PBDEs for adults in Beijing were 2.52, 2.74 and 9.77 ng/kg body weight/day, respectively. Meat consumption was found to be the primary source of BFR dietary intake. A comparison between the calculated estimated daily intakes (EDIs) and the corresponding threshold reference values (TRVs) indicated that daily intake of BFRs via food consumption is unable to cause significant health risks. Likewise, the margin of exposures (MOEs) calculated following the European Food Safety Authority (EFSA) approach were far higher than the threshold, which also proved that the EDIs of BFRs are unlikely to raise significant health concerns.
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Affiliation(s)
- Jiandi Wang
- Shunyi Maternal and Children's Hospital of Beijing Children's Hospital, Capital Medical University, Beijing 110113, China; School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Xuezhen Zhao
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Yifei Wang
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China.
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Vervliet P, Den Plas JV, De Nys S, Duca RC, Boonen I, Elskens M, Van Landuyt KL, Covaci A. Investigating the in vitro metabolism of the dental resin monomers BisGMA, BisPMA, TCD-DI-HEA and UDMA using human liver microsomes and quadrupole time of flight mass spectrometry. Toxicology 2019; 420:1-10. [DOI: 10.1016/j.tox.2019.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/16/2019] [Accepted: 03/20/2019] [Indexed: 12/30/2022]
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Huang H, Wang D, Wen B, Lv J, Zhang S. Roles of maize cytochrome P450 (CYP) enzymes in stereo-selective metabolism of hexabromocyclododecanes (HBCDs) as evidenced by in vitro degradation, biological response and in silico studies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 656:364-372. [PMID: 30513427 DOI: 10.1016/j.scitotenv.2018.11.351] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/21/2018] [Accepted: 11/24/2018] [Indexed: 06/09/2023]
Abstract
In vitro biotransformation of HBCDs by maize cytochrome P450 (CYP) enzymes, responses of CYPs to HBCDs at protein and transcription levels, and in silico simulation of interactions between CYPs and HBCDs were investigated in order to elucidate the roles of CYPs in the metabolism of HBCDs in maize. The results showed that degradation reactions of HBCDs by maize microsomal CYPs followed the first-order kinetics and were stereo-selective, with the metabolic rates following the order (-)γ- > (+)γ- > (+)α- > (-)α-HBCD. The hydroxylated metabolites OH-HBCDs, OH-PBCDs and OH-TBCDs were detected. (+)/(-)-α-HBCDs significantly decreased maize CYP protein content and inhibited CYP enzyme activity, whereas (+)/(-)-γ-HBCDs had obvious effects on the induction of CYPs. HBCDs selectively mediated the gene expression of maize CYPs, including the isoforms of CYP71C3v2, CYP71C1, CYP81A1, CYP92A1 and CYP97A16. Molecular docking results suggested that HBCDs could bind with these five CYPs, with binding affinity following the order CYP71C3v2 < CYP81A1 < CYP97A16 < CYP92A1 < CYP71C1. The shortest distances between the Br-unsubstituted C atom of HBCD isomers and the iron atom of heme in CYPs were 4.18-11.7 Å, with only the distances for CYP71C3v2 being shorter than 6 Å (4.61-5.38 Å). These results suggested that CYP71C3v2 was an efficient catalyst for degradation of HBCDs. For (+)α- and (-)γ-HBCDs, their binding affinities to CYPs were lower and the distances to the iron atom of heme in CYPs were shorter than their corresponding antipodes, consistent with the in vitro experimental results showing that they had shorter half-lives and were more easily hydroxylated. This study provides solid evidence for the roles of maize CYPs in the metabolism of HBCDs, and gives insight into the molecular mechanisms of the enantio-selective metabolism of HBCDs by plant CYPs.
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Affiliation(s)
- Honglin Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China
| | - Dan Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bei Wen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China
| | - Jitao Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China
| | - Shuzhen Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Okonski K, Melymuk L, Kohoutek J, Klánová J. Hexabromocyclododecane: concentrations and isomer profiles from sources to environmental sinks. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:36624-36635. [PMID: 30377961 DOI: 10.1007/s11356-018-3381-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 10/01/2018] [Indexed: 06/08/2023]
Abstract
Concentrations and isomer compositions of hexabromocyclododecane (HBCD) were measured in six matrices in the Czech Republic (HBCD technical mixture; consumer products; indoor and outdoor air at industrial, urban and background locations; soils; and sediments) to provide insight into changes in concentrations and isomer profiles between environmental sources and environmental sinks. A distinct gradient of air concentrations was observed, from 1600 ng/m3 in the industrial area to < 10 pg/m3 in urban and background air. Isomer profiles also showed a distinct gradient in air, from 95% γ-HBCD in industrial air to 40% γ-HBCD in background air, suggesting the influence of differential atmospheric transport and phototransformation of γ- to α-HBCD. Concentrations and isomer compositions in consumer products were highly variable and indicated differences between products with intentional addition of HBCD as a flame retardant versus those with HBCD as an impurity, e.g., from recycled plastic. Understanding the isomer-specific environmental distributions and processes remains important for risk assessment and toxicology, considering the continued use of HBCD and the isomer-specific differences in uptake, metabolism, and toxicity, and further, demonstrates the utility of isomer profiles to better understand environmental processes of HBCDs.
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Affiliation(s)
- Krzysztof Okonski
- Faculty of Science, RECETOX (Research Centre for Toxic Compounds in the Environment), Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Lisa Melymuk
- Faculty of Science, RECETOX (Research Centre for Toxic Compounds in the Environment), Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic.
| | - Jiří Kohoutek
- Faculty of Science, RECETOX (Research Centre for Toxic Compounds in the Environment), Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
| | - Jana Klánová
- Faculty of Science, RECETOX (Research Centre for Toxic Compounds in the Environment), Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
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Vervliet P, Mortelé O, Gys C, Degreef M, Lanckmans K, Maudens K, Covaci A, van Nuijs ALN, Lai FY. Suspect and non-target screening workflows to investigate the in vitro and in vivo metabolism of the synthetic cannabinoid 5Cl-THJ-018. Drug Test Anal 2018; 11:479-491. [PMID: 30242979 DOI: 10.1002/dta.2508] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 02/06/2023]
Abstract
The use of synthetic cannabinoids causes similar effects as Δ9 -tetrahydrocannabinol and long-term (ab)use can lead to health hazards and fatal intoxications. As most investigated synthetic cannabinoids undergo extensive biotransformation, almost no parent compound can be detected in urine, which hampers forensic investigations. Limited information about the biotransformation products of new synthetic cannabinoids makes the detection of these drugs in various biological matrices challenging. This study aimed to identify the main in vitro biotransformation pathways of 5Cl-THJ-018 and to compare these findings with an authentic urine sample of a 5Cl-THJ-018 user. The synthetic cannabinoid was incubated with pooled human liver microsomes and cytosol to simulate phase I and phase II biotransformations. Resulting extracts were analyzed with liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Three different data analysis workflows were applied to identify biotransformation products. A suspect screening workflow used an in-house database built from literature data and in silico biotransformation predictions. Two non-target screening workflows used a commercially available software and an open-source software for mass spectrometry data processing. A total of 23 in vitro biotransformation products were identified, with hydroxylation, oxidative dechlorination, and dihydrodiol formation pathways as the main phase I reactions. Additionally, five glucuronidated and three sulfated phase II conjugates were identified. The predominant in vivo pathway was through oxidative dechlorination and in total six metabolites of 5Cl-THJ-018 were identified. Biotransformation products both in vitro and in vivo were successfully identified using complementary suspect and non-target screening workflows.
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Affiliation(s)
| | - Olivier Mortelé
- Toxicological Centre, University of Antwerp, Antwerp, Belgium
| | - Celine Gys
- Toxicological Centre, University of Antwerp, Antwerp, Belgium
| | - Maarten Degreef
- Toxicological Centre, University of Antwerp, Antwerp, Belgium
| | | | - Kristof Maudens
- Toxicological Centre, University of Antwerp, Antwerp, Belgium
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Antwerp, Belgium
| | | | - Foon Yin Lai
- Toxicological Centre, University of Antwerp, Antwerp, Belgium
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Dong H, Lu G, Yan Z, Liu J, Nkoom M, Yang H. Responses of antioxidant and biotransformation enzymes in Carassius carassius exposed to hexabromocyclododecane. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 62:46-53. [PMID: 29960092 DOI: 10.1016/j.etap.2018.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/04/2018] [Accepted: 06/24/2018] [Indexed: 06/08/2023]
Abstract
The ubiquitous existence of hexabromocyclododecane (HBCD) in environmental matrices has made it attractive to both field investigators as well as laboratory researchers. However, literature on the biological effects caused by HBCD on aquatic vertebrates seldom exist. This has inevitably increased the difficulty of toxicological assessment in the aquatic environment. Juvenile crucian carp (Carassius carassius) were exposed (flow-through) to different concentrations of technical HBCD (nominal 2, 20, 200 μg L-1) for 7 days to determine the responses of antioxidant and biotransformation enzymes. HBCD was found to be increasingly bioconcentrated in the fish livers as time proceeds. Also, the contribution of α-HBCD exhibited an enhancement from 13% in the exposure solutions to 24% in crucian carp, still much lower than in wild fishes (ca. 80%). HBCD induced activities of antioxidant enzymes in most cases, as well as increased level of lipid peroxidation. In contrast to the weak response of 7-ethoxyresorufin-O-deethylase (EROD), 7-pentoxyresorufin-O-depentylase (PROD) activity was generally induced in a time-dependent manner with peaks at day 2. Phase II enzyme Glutathione-S-transferase (GST) showed a dose-dependent induction with maximums in the 20 μg L-1 treatment at all the four timepoints of 1, 2, 4 and 7 days. Some enzymatic responses showed good associations, indicating coordinated functions. To sum up, tHBCD exposure in the present circumstance had produced an ecological stress to crucian carp. The low levels of biotransformation and slow rates of bioisomerization suggest a possible long-term toxic effect, especially around HBCD point sources.
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Affiliation(s)
- Huike Dong
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Guanghua Lu
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China; Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi 860000, China.
| | - Zhenhua Yan
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Jianchao Liu
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Matthew Nkoom
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Haohan Yang
- Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
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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: 7.5] [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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Su G, McGoldrick DJ, Clark MG, Evans MS, Gledhill M, Garron C, Armelin A, Backus SM, Letcher RJ. Isomer-Specific Hexabromocyclododecane (HBCDD) Levels in Top Predator Fish from Across Canada and 36-Year Temporal Trends in Lake Ontario. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:6197-6207. [PMID: 29737158 DOI: 10.1021/acs.est.8b01052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hexabromocyclododecane (HBCDD) is a high concern environmental pollutant due to its persistent, bioaccumulative, and toxic properties. The spatial distribution of HBCDD was investigated in top predator fish (lake trout, walleye, or brook trout) collected in 2013 ( n = 165) from 19 sampling sites and in 2015 ( n = 145) from 20 sites across Canada. HBCDD was measurable in at least one sample at each sampling site regardless of sampling year with the exception of walleye from the south basin of Lake Winnipeg (2013). Sampling sites in or near the Laurentian Great Lakes had greater ΣHBCDD concentrations compared to locations to the west or east. The greatest mean ΣHBCDD concentration was 72.6 ng/g lw in fish from Lake Huron-Goderich (2015). Regardless of the sampling sites, α-HBCDD was the dominant congener followed by γ-HBCDD, whereas β-HBCDD was barely detectable. In fish from the same waterbody there were comparable α/γ isomer concentration ratios. The greatest ratio was 20.8 in fish from Lake Ontario, whereas the lowest ratio was 6.3 for fish from Lac Memphrémagog (Québec) likely related to more recent emissions of a technical HBCDD mixture. Temporal trends of HBCDD in lake trout from Lake Ontario showed a significant decreasing trend for γ-HBCDD with a half-life estimate of 10 years over a 36-year period (1979-2015), and for α-HBCDD with a half-life of 11 years over the years of 2008 to 2015. The proportion of α-HBCDD to ΣHBCDD increased significantly during 1979 to 2015. The present study provided novel information on the isomer-specific HBCDDs in Canada freshwater fish.
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Affiliation(s)
- Guanyong Su
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering , Nanjing University of Science and Technology , Nanjing 210094 , People's Republic of China
| | - Daryl J McGoldrick
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Mandi G Clark
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Marlene S Evans
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Melissa Gledhill
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Christine Garron
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Alain Armelin
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Sean M Backus
- Water Science and Technology Directorate, Science and Technology Branch , Environment and Climate Change Canada , Burlington , Ontario L7S 1A1 , Canada
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre , Carleton University , Ottawa , Ontario K1A 0H3 , Canada
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In vitro Phase I and Phase II metabolism of the new designer benzodiazepine cloniprazepam using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. J Pharm Biomed Anal 2018; 153:158-167. [DOI: 10.1016/j.jpba.2018.02.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/07/2018] [Accepted: 02/16/2018] [Indexed: 11/22/2022]
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Abdallah MAE, Sharkey M, Berresheim H, Harrad S. Hexabromocyclododecane in polystyrene packaging: A downside of recycling? CHEMOSPHERE 2018; 199:612-616. [PMID: 29459351 DOI: 10.1016/j.chemosphere.2018.02.084] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/12/2018] [Accepted: 02/13/2018] [Indexed: 06/08/2023]
Abstract
While there are no regulatory fire safety obligations for polystyrene (PS) when used as packaging material, concerns exist that such packaging material may contain the flame retardant hexabromocyclododecane (HBCDD) as a result of uncontrolled recycling activities. To evaluate these concerns, we collected 50 samples of PS packaging materials from the UK and 20 from Ireland. HBCDD was detected in 63 (90%) of samples, with concentrations in 4 samples from Ireland exceeding the EU's low POP concentration limit (LPCL) of 0.1% above which articles may not be recycled. Moreover, 2 further samples contained HBCDD >0.01%. While our samples were obtained in the 12 month period prior to the March 2016 introduction of the EU's 0.01% concentration limit above which articles may not be placed on the market, our data suggest that continued monitoring is required to assess compliance with this limit value. Ratios of α vs. γ-HBCDD in our EPS packaging samples (average = 0.63) exceeded significantly (p = 0.025) those in EPS building insulation material samples (average = 0.24) reported previously for Ireland. This shift towards α-HBCDD in packaging EPS is consistent with the additional thermal processing experienced by recycled PS and suggests the source of HBCDD in PS packaging is recycled PS insulation foam. This is of concern owing to the higher bioavailability and lower metabolic clearance of α-HBCDD compared to the β- and γ-isomers.
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Affiliation(s)
- Mohamed Abou-Elwafa Abdallah
- School of Geography, Earth & Environmental Sciences, University of Birmingham, UK; Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut, Egypt
| | - Martin Sharkey
- School of Physics, National University of Ireland Galway, Ireland
| | | | - Stuart Harrad
- School of Geography, Earth & Environmental Sciences, University of Birmingham, UK.
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Lu S, Tan Z, Jiang Y, Wu D, Zhang J, Zhou J, Lin X. Hexabromocyclododecanes in breast milk from residents in Shenzhen, China: Implications for infant exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1090-1097. [PMID: 29890578 DOI: 10.1016/j.scitotenv.2017.11.277] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 06/08/2023]
Abstract
Hexabromocyclododecanes (HBCDs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about HBCD exposure for humans, especially in China. This study aimed to investigate the levels and profiles of hexabromocyclododecanes (HBCDs) in human breast milk and to estimate the daily HBCD intake for infants in Shenzhen, China. Levels of the HBCD diastereoisomers α-, β-, and γ-HBCD in 180 breast milk samples collected from primiparas in Shenzhen were measured. The concentrations of α-, β-, and γ-HBCD (ΣHBCDs) ranged within 0.103-15.1ng/g lipid and had a median of 1.82ng/g lipid. ΣHBCDs levels in milk in the present study are comparable to those in milk from other countries and regions but are markedly higher than those for most populations in other regions of China. Among the diastereoisomers, α-HBCD was predominant, accounting for 97.6% of the concentration of ΣHBCDs. The estimated daily intake of ΣHBCDs via breast milk for infants in Shenzhen ranged from 0.481 to 100ng/kgbw/day with a median of 8.40ng/kgbw/day, however, which was unlikely to raises a health concern based on the margin of exposure (MOE) approach. The duration of residence was found to have a significant positive correlation with the HBCD levels in the human breast milk (p<0.05). To our knowledge, this is the first report on HBCD levels in breast milk from Shenzhen residents.
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Affiliation(s)
- Shaoyou Lu
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Zhen Tan
- Shenzhen Academy of Metrology & Quality Inspection, Shenzhen 518131, China
| | - Yousheng Jiang
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Dongting Wu
- School of Medicine, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Jianqing Zhang
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
| | - Jian Zhou
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Xiaoshi Lin
- POPs Lab, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
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Shi Z, Zhang L, Li J, Wu Y. Legacy and emerging brominated flame retardants in China: A review on food and human milk contamination, human dietary exposure and risk assessment. CHEMOSPHERE 2018; 198:522-536. [PMID: 29428767 DOI: 10.1016/j.chemosphere.2018.01.161] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/18/2018] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
Brominated flame retardants (BFRs) are a large group of widely used chemicals, which have been produced and used since 1970s. As a consequence of substantial and long-term usage, BFRs have been found to be ubiquitous in humans, wildlife, and abiotic matrices around the world. Although several reports have reviewed BFRs contamination in general, none have focused specifically on foods and human milk, and the corresponding dietary exposure. Foods (including human milk) have long been recognized as a major pathway of BFRs intake for non-occupationally exposed persons. This review summarizes most available BFRs data in foods and human milk from China in recent years, and emphasizes several specific aspects, i.e., contamination levels of legacy and emerging BFRs, dietary exposure assessment and related health concerns, comparison between various BFRs, and temporal changes in BFRs contamination.
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Affiliation(s)
- Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Lei Zhang
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Jingguang Li
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Yongning Wu
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China.
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Shi Z, Zhang L, Zhao Y, Sun Z, Zhou X, Li J, Wu Y. A national survey of tetrabromobisphenol-A, hexabromocyclododecane and decabrominated diphenyl ether in human milk from China: Occurrence and exposure assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:237-245. [PMID: 28477480 DOI: 10.1016/j.scitotenv.2017.04.237] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/29/2017] [Accepted: 04/29/2017] [Indexed: 06/07/2023]
Abstract
A national survey of three currently used brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and decabrominated diphenyl ether (BDE-209) in human milk was conducted in 2011. Human milk from 16 provinces of China were collected, pooled and measured. The estimated daily intake (EDI) via human milk ingestion for nursing infant and the related health risks were evaluated. The median levels of TBBPA, HBCD and BDE-209 were 1.21, 6.83 and 0.556ng/g lipid weight (lw), respectively. Levels of BDE-209 were lower than those of TBBPA, indicating that the production and application of deca-BDE in China has been below that of TBBPA after the restriction of PBDEs. Moreover, contamination levels of TBBPA and HBCD in this survey were higher than those observed in last national survey conducted in 2007, indicating an increase of TBBPA and HBCD in the environment from 2007 to 2011. The mean estimated daily intakes (EDIs) of TBBPA, HBCD and BDE-209 via human milk for 1-6months old infant were 39.2, 51.7 and 3.65ng/kgbw/day, respectively. For risk assessment, margin of exposure (MOE) was calculated by comparing the BMDL10 (benchmark dose lower confidence limit for a benchmark response of 10%) to the EDI of each BFR. Large MOEs indicates that the estimated dietary exposure to these three BFRs for nursing infant is unlikely to raise significant health concerns. Compared with some currently used novel BFRs which also measured in this survey, higher contamination levels were found in some non-PBDE BFRs, indicating that the consumption pattern of BFRs has shifted from PBDEs to non-PBDE BFRs in China.
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Affiliation(s)
- Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China.
| | - Lei Zhang
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Yunfeng Zhao
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Zhiwei Sun
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Xianqing Zhou
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Jingguang Li
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China.
| | - Yongning Wu
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
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Shi Z, Zhang L, Zhao Y, Sun Z, Zhou X, Li J, Wu Y. Dietary exposure assessment of Chinese population to tetrabromobisphenol-A, hexabromocyclododecane and decabrominated diphenyl ether: Results of the 5th Chinese Total Diet Study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 229:539-547. [PMID: 28688304 DOI: 10.1016/j.envpol.2017.06.093] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
Based on the 5th Chinese Total Diet Study (TDS) carried out in 2011, the dietary exposure of Chinese population to three currently used brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and decabrominated diphenyl ether (BDE-209), was estimated and the related health risks were assessed. Levels of the three BFRs were determined in 80 composite samples from four animal-origin food groups. The average levels of BFRs in various food groups ranged from 0.671 to 5.76 ng/g lipid weight (lw). The levels of TBBPA were lower than those of HBCD but higher than those of BDE-209. Moreover, average contamination levels of TBBPA and HBCD in TDS 2011 were found to be 3 to 30 times higher than those observed in TDS 2007 in the four food groups, indicating an increase in TBBPA and HBCD in the environment during 2007-2011. The average estimated daily intakes (EDIs) of TBBPA, HBCD and BDE-209 via food consumption for a "standard Chinese man" were 1.34, 1.51 and 0.96 ng/kg bw/day, respectively. Meat and meat products were found to be the major contributor to the daily dietary intake because the consumption of meat and meat products were significantly higher than that of other food groups in China. In comparison, the levels and EDIs of BFRs in this study were found to be higher than those in most studies worldwide. However, the large margin of exposure (MOE), with at least 1.1 × 105 calculated following the European Food Safety Authority (EFSA) approach, indicates that the estimated dietary exposure to these three BFRs is unlikely to raise significant health concerns. In addition, a comparison between the contamination levels of TBBPA, HBCD, BDE-209 and some novel BFRs in food samples from TDS 2011 indicated an obvious shift in the industrial production and usage pattern between PBDE and non-PBDE BFRs in China.
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Affiliation(s)
- Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China.
| | - Lei Zhang
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Yunfeng Zhao
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Zhiwei Sun
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Xianqing Zhou
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Jingguang Li
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, China.
| | - Yongning Wu
- The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, Beijing 100021, 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: 3.4] [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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Huang H, Wang D, Wan W, Wen B. Hexabromocyclododecanes in soils and plants from a plastic waste treatment area in North China: occurrence, diastereomer- and enantiomer-specific profiles, and metabolization. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:21625-21635. [PMID: 28752306 DOI: 10.1007/s11356-017-9792-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
Plastic waste is a source of organic contaminants such as hexabromocyclododecanes (HBCDs). HBCDs have been found to cause developmental and reproductive toxicity; it is important to investigate the occurrence and metabolization of HBCDs in the soil environments with plastic waste contamination. This work analyzed HBCDs and their metabolites in soil and plant samples collected from Xinle and Dingzhou-the major plastic waste recycling centers in North China. Results showed that total HBCD concentrations in soils followed the order: plastic waste treatment site (11.0-624 ng/g) > roadside (2.96-85.4 ng/g) ≥ farmland (8.69-55.5 ng/g). HBCDs were detected in all the plant samples with total concentrations ranging from 3.47 to 23.4 ng/g. γ-HBCD was the dominant congener in soils, while α-HBCD was preferentially accumulated in plants. Compositions of HBCD isomers in soils and plants were significantly different (P < 0.05) among sampling sites and among plant species. HBCDs in farmland soil and all plant samples exhibited high enantio-selectivity based on the enantiomeric fractions (EFs). Furthermore, metabolites of pentabromocyclododecenes (PBCDEs) were frequently identified in soils, and mono-OH-HBCDs were the most common ones in plants. This study for the first time provides evidences of HBCD contamination in the soil-plant system caused by plastic waste, their stereo-selectivity, and metabolization behavior, improving our understanding of the environmental behavior and fate of HBCDs.
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Affiliation(s)
- Honglin Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China.
| | - Dan Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weining Wan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China
| | - Bei Wen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China
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