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González-Doncel M, Torija CF, Beltrán EM, García-Mauriño JE, Sastre S, Carbonell G. Limitations of waterborne exposure of fish early life stages to BDE-47. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 148:184-194. [PMID: 24508762 DOI: 10.1016/j.aquatox.2014.01.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/10/2013] [Accepted: 01/15/2014] [Indexed: 06/03/2023]
Abstract
2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) is acknowledged as the most abundant congener of all polybrominated diphenyl ethers (PBDEs). Despite its limited residence in the water column, most ecotoxicological research using fish early life stages (ELS) has focused on its waterborne bioavailability. These studies have been supported either by chemical analysis in solutions or in tissues after ≤ 168 h exposures to relatively high waterborne concentrations with dimethyl sulfoxide (DMSO) as solvent carrier (≤ 0.5%). Using noninvasive physiological and anatomical features in medaka ELS, we investigated the viability of waterborne BDE-47 exposures (100-10,000 μg/L; 1% DMSO) and evaluated the developmental effects in relation to the actual BDE-47 present in water. Embryos were exposed for 10 days under semi-static (24-h renewal) conditions and waterborne BDE-47 concentrations (i.e., dissolved) were quantitated daily and their accumulation in eleutheroembryonic tissues was analyzed 4 days after exposures finished. BDE-47 in solution rapidly decreased after each renewal by >50% in 24h. This was confirmed by discernible precipitation occurring at ≥ 5,000 μg/L on the bottom of the container and attached to the chorionic filaments of eggshell. The fast dissipation from water may explain why, besides the subtle, yet significant effects on post-hatching growth (short length at ≥5000μg/L), no other significant deleterious developmental effects were observed despite the fact that BDE-47 accumulated in tissues in response to BDE-47 treatment. Waterborne BDE-47 exposure was unachievable under traditional semi-static exposure conditions, but was achievable in repeated pulse exposures lasting a few hours whenever the medium was renewed. Hence, this research encourages the use of alternate - more realistic - exposure routes (e.g., particulate matter or sediments) when evaluating early developmental toxicity of BDE-47 or any other PBDE sharing similar properties.
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Affiliation(s)
- Miguel González-Doncel
- Laboratory for Ecotoxicology, Department of the Environment, National Institute for Agricultural and Food Research and Technology, A-6, Km. 7.5, E-28040 Madrid, Spain.
| | - Carlos Fernández Torija
- Laboratory for Ecotoxicology, Department of the Environment, National Institute for Agricultural and Food Research and Technology, A-6, Km. 7.5, E-28040 Madrid, Spain
| | - Eulalia María Beltrán
- Laboratory for Ecotoxicology, Department of the Environment, National Institute for Agricultural and Food Research and Technology, A-6, Km. 7.5, E-28040 Madrid, Spain
| | - José Enrique García-Mauriño
- Department of Cell Biology, School of Medicine, Complutense University, Ciudad Universitaria, E-28040 Madrid, Spain
| | - Salvador Sastre
- Laboratory of Forest Soils, Department of Forest Ecology, National Institute for Agricultural and Food Research and Technology, A-6, Km. 7.5, E-28040 Madrid, Spain
| | - Gregoria Carbonell
- Laboratory for Ecotoxicology, Department of the Environment, National Institute for Agricultural and Food Research and Technology, A-6, Km. 7.5, E-28040 Madrid, Spain
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Wang Q, Chen Q, Zhou P, Li W, Wang J, Huang C, Wang X, Lin K, Zhou B. Bioconcentration and metabolism of BDE-209 in the presence of titanium dioxide nanoparticles and impact on the thyroid endocrine system and neuronal development in zebrafish larvae. Nanotoxicology 2014; 8 Suppl 1:196-207. [DOI: 10.3109/17435390.2013.875232] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Qiangwei Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China,
- Graduate University of Chinese Academy of Sciences, Beijing, China,
| | - Qi Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China,
- Graduate University of Chinese Academy of Sciences, Beijing, China,
| | - Peng Zhou
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, China, and
| | - Wenwen Li
- Institute of Watershed Science and Environmental Ecology, Wenzhou Medical University, Wenzhou, China
| | - Junxia Wang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, China, and
| | - Changjiang Huang
- Institute of Watershed Science and Environmental Ecology, Wenzhou Medical University, Wenzhou, China
| | - Xianfeng Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China,
| | - Kuangfei Lin
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, China, and
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China,
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Zhao J, Xu T, Yin DQ. Locomotor activity changes on zebrafish larvae with different 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) embryonic exposure modes. CHEMOSPHERE 2014; 94:53-61. [PMID: 24080000 DOI: 10.1016/j.chemosphere.2013.09.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 08/22/2013] [Accepted: 09/02/2013] [Indexed: 06/02/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widely used flame retardants and are banned around the world as potent environmental contaminants. PBDE-47 is the most concerned PBDE with its environmental prevalence and various toxicity characteristics including neurotoxicity. In this paper, we studied larval zebrafish behavioral alterations caused by PBDE-47 neurotoxicity. The light-dark cycle stimulation was used to investigate the locomotor changes of zebrafish larvae at different ages (4-6 day post-fertilization, dpf) after PBDE-47 exposure (5, 50, 500 μg L(-1)). Three exposure modes, namely continuous exposure, early pulse exposure and interval exposure, were adopted to assess and compare the impacts of exposure modes on larval zebrafish locomotion. Our results showed that locomotor effects upon PBDE exposure depended on the specific exposure mode studied. In the early pulse exposure mode, the locomotion of zebrafish larvae did not change significantly at all PBDE-47 concentrations tested. In contrast, for both the continuous exposure and interval exposure modes, the highest dose of PBDE-47 (500 μg L(-1)) elicited pronounced hypoactivity at 5 dpf during dark periods except for the initial one. However, at 6 dpf, hypoactivity was only observed in the continuously exposed zebrafish larvae (to an even higher degree compared to 5 dpf), but not in the interval exposure treatment group. Our results suggested that the conventional, continuous exposure mode might not be enough to evaluate the toxicity of chemicals in the real environments.
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Affiliation(s)
- Jing Zhao
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Technology, Tongji University, Shanghai 200092, China
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Li W, Zhu L, Zha J, Wang Z. Effects of decabromodiphenyl ether (BDE-209) on mRNA transcription of thyroid hormone pathway and spermatogenesis associated genes in Chinese rare minnow (Gobiocypris rarus). ENVIRONMENTAL TOXICOLOGY 2014; 29:1-9. [PMID: 21901812 DOI: 10.1002/tox.20767] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Revised: 07/12/2011] [Accepted: 07/22/2011] [Indexed: 05/31/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants, which are ubiquitous environmental contaminant found in both abiotic and biotic environmental samples. Deca-BDE (BDE-209) is the principal component, which is currently used worldwide. In this study, the effect of BDE-209 on the mRNA levels of thyroid hormone (TH) related genes and spermatogenesis associated genes were determined from larvae and adult rare minnow (Gobiocypris rarus) exposed to concentrations 0.01, 0.1, 1, and 10 μg/L for 21 days. The results showed that the type II deiodinase (dio2) and sodium iodide symporter (nis) mRNA levels were significantly up-regulated in the larvae at 10 μg/L treatment. In adult, histopathological observations showed that liver of female fish were degenerated at 10 μg/L treatment, and inhibition of spermatogenesis were observed in testis of male fish. In addition, the thyroid hormone receptor α (trα), dio2, and nis mRNA levels in the liver of male and female fish were significantly up-regulated, whereas dio2 and nis mRNA levels were significantly down-regulated in the brain. These results indicate that exposure to BDE-209 could result in tissue-specific alternations of TH-related genes expression in adults. Moreover, the mRNA levels of the testis-specific apoptosis genes, the spermatogenesis-associated 4 (spata4) and spermatogenesis-associated 17 (spata17), were down-regulated at 10 μg/L treatment in testis of male fish. Our results suggest that BDE-209 may pose threat to normal thyroid and reproductive function in fish.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, People's Republic of China
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Torres L, Orazio CE, Peterman PH, Patiño R. Effects of dietary exposure to brominated flame retardant BDE-47 on thyroid condition, gonadal development and growth of zebrafish. FISH PHYSIOLOGY AND BIOCHEMISTRY 2013; 39:1115-1128. [PMID: 23334565 DOI: 10.1007/s10695-012-9768-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 12/31/2012] [Indexed: 06/01/2023]
Abstract
Little is known about the effects of brominated flame retardants in teleosts and some of the information currently available is inconsistent. This study examined effects of dietary exposure to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on thyroid condition, body mass and size, and gonadal development of zebrafish. Pubertal, 49-day-old (posthatch) fish were fed diets without BDE-47 (control) or with 1, 5 or 25 μg/g BDE-47/diet. Treatments were conducted in triplicate 30-L tanks each containing 50 zebrafish, and 15 fish per treatment (5 per tank) were sampled at days 40, 80 and 120 of exposure. Measurements were taken of body mass, standard length, head depth and head length. Sex (at 40-120 days of exposure), germ cell stage (at 40 days) and thyroid condition (at 120 days; follicular cell height, colloid depletion, angiogenesis) were histologically determined. Whole-body BDE-47 levels at study completion were within the high end of levels reported in environmentally exposed (wild) fishes. Analysis of variance was used to determine differences among treatments at each sampling time. No effects were observed on thyroid condition or germ cell stage in either sex. Reduced head length was observed in females exposed to BDE-47 at 80 days but not at 40 or 120 days. In males, no apparent effects of BDE-47 were observed at 40 and 80 days, but fish exposed to 25 μg/g had lower body mass at 120 days compared to control fish. These observations suggest that BDE-47 at environmentally relevant whole-body concentrations does not affect thyroid condition or pubertal development of zebrafish but does affect growth during the juvenile-to-adult transition, especially in males.
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Affiliation(s)
- Leticia Torres
- Department of Biological Sciences and Texas Cooperative Fish and Wildlife Research Unit, Texas Tech University, Lubbock, TX, 79409-3131, USA
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Ji C, Wu H, Wei L, Zhao J, Yu J. Proteomic and metabolomic analysis reveal gender-specific responses of mussel Mytilus galloprovincialis to 2,2',4,4'-tetrabromodiphenyl ether (BDE 47). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 140-141:449-457. [PMID: 23938206 DOI: 10.1016/j.aquatox.2013.07.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 07/15/2013] [Accepted: 07/15/2013] [Indexed: 06/02/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame-retardants (BFRs) that are widely used in industrial products and have posed potential risk on the coastal environment of the Laizhou Bay in China. They are of great concern due to their toxicities, such as hepatotoxicity, carcinogenecity, neurotoxicity, immunotoxicity and endocrine disrupting effects in animals. In this work, we focused on the gender-specific responses of BDE 47 in mussel Mytilus galloprovincialis using a combined proteomic and metabolomic approach. Metabolic responses indicated that BDE 47 mainly caused disturbance in energy metabolism in male mussel gills. For female mussel samples, disruption in both osmotic regulation and energy metabolism was found in terms of differential metabolic profiles. Proteomic responses revealed that BDE 47 induced cell apoptosis and reduced reactive oxygen species (ROS) production in both male and female mussels, disturbance in protein homeostasis in male mussels as well as disturbance in female mussel proteolysis based on the differential proteomic biomarkers. Overall, these results confirmed the gender-specific responses in mussels to BDE 47 exposures. This work demonstrated that an integrated metabolomic and proteomic approach could provide an important insight into the toxicological effects of environmental pollutant to organisms.
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Affiliation(s)
- Chenglong Ji
- Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Yantai 264003, PR China
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Abstract
In the current study, two of the most environmentally relevant Polybrominated diphenyl ethers (PBDEs) were individually evaluated for toxic effects on rotifer Brachionus plicatilis. The results showed that the life span declined significantly in all treatment groups (0.05mg/L, 0.1mg/L, 0.2mg/L BDE-47 and BDE-209) compared to the control, and BDE-47 caused significant decrease compared to BDE-209 at 0.2mg/L treatment group. Significant increases of intracellular levels of reactive oxygen species (ROS) occurred in all treatment groups except for 0.05mg/L BDE-209 treatment group compared to the control, and significant increases were observed in all BDE-47 treatment groups compared to the equivalent treatment groups of BDE-209. Meanwhile significant increases of intracellular calcium levels ([Ca2+]in) occurred in 0.1mg/L, 0.2mg/L BDE-47 and 0.2mg/L BDE-209 treatment groups compared to the control, and BDE-47 cause significant increase compared to BDE-209 at 0.2mg/L treatment group. The present study demonstrated that life span, ROS and Ca2+ were involved in PBDEs toxic effects, and toxicities of BDE-47 were higher than BDE-209. Otherwise, the toxic effects in both BDE-47 and BDE-209 were similar, which suggest that the toxic effects of two PBDEs congeners may be caused by the same toxic mechanism of action.
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Barja-Fernández S, Míguez JM, Alvarez-Otero R. Histopathological effects of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in the gills, intestine and liver of turbot (Psetta maxima). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 95:60-8. [PMID: 23816362 DOI: 10.1016/j.ecoenv.2013.05.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 05/22/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental pollutants because of their widespread use as flame retardants in various consumer products (plastics, textiles, electronic appliances and building materials) and their long half-life. BDE-47 (2,2',4,4'-tetrabromodiphenyl ether) is the major PBDE congener detected in the environment and in animal tissues. In the present study, the histopathological effects are examined of BDE-47 on the gills, intestine and liver tissues of juvenile turbot (Psetta maxima).The specimens were exposed to two concentrations of BDE-47 (0.03 and 0.3 µg/L) for a period of 15 days. The histological changes were detected microscopically and evaluated with quantitative or semi-quantitative analyses. At the doses of BDE-47 assayed, the most common gill injuries were lamellar fusion, blood congestion and hyperplasia and hypertrophy of the epithelial and mucous cells. In the intestine of fish exposed to BDE-47, the alterations detected were hyperplasia and hypertrophy of mucous cells. Hepatic lesions in the liver of fish exposed to BDE-47 were characterized by circulatory disturbances, irregular morphology of hepatocytes, cellular and nuclear hypertrophy, and nuclear vacuolation and pyknosis. As BDE-47 is present in food and other material related to aquaculture systems, our results indicate that exposure to this pollutant could have serious consequences on health in turbot and other cultured fish.
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Affiliation(s)
- Silvia Barja-Fernández
- Laboratorio de Biología Celular, Departamento de Biología Funcional y Ciencias de la Salud, Facultad de Biología, Universidad de Vigo, Vigo, Spain
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59
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Ingebretson JJ, Masino MA. Quantification of locomotor activity in larval zebrafish: considerations for the design of high-throughput behavioral studies. Front Neural Circuits 2013; 7:109. [PMID: 23772207 PMCID: PMC3677137 DOI: 10.3389/fncir.2013.00109] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/22/2013] [Indexed: 01/29/2023] Open
Abstract
High-throughput behavioral studies using larval zebrafish often assess locomotor activity to determine the effects of experimental perturbations. However, the results reported by different groups are difficult to compare because there is not a standardized experimental paradigm or measure of locomotor activity. To address this, we investigated the effects that several factors, including the stage of larval development and the physical dimensions (depth and diameter) of the behavioral arena, have on the locomotor activity produced by larval zebrafish. We provide evidence for differences in locomotor activity between larvae at different stages and when recorded in wells of different depths, but not in wells of different diameters. We also show that the variability for most properties of locomotor activity is less for older than younger larvae, which is consistent with previous reports. Finally, we show that conflicting interpretations of activity level can occur when activity is assessed with a single measure of locomotor activity. Thus, we conclude that although a combination of factors should be considered when designing behavioral experiments, the use of older larvae in deep wells will reduce the variability of locomotor activity, and that multiple properties of locomotor activity should be measured to determine activity level.
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Chen L, Huang Y, Huang C, Hu B, Hu C, Zhou B. Acute exposure to DE-71 causes alterations in visual behavior in zebrafish larvae. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:1370-1375. [PMID: 23400899 DOI: 10.1002/etc.2168] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/28/2012] [Accepted: 01/03/2013] [Indexed: 06/01/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) cause neurobehavioral toxicity, but their effects on visual behavior remain unknown. In the present study, the impact of PBDEs on visual behavior was examined using optokinetic responses and phototaxis in zebrafish larvae. Zebrafish embryos were exposed to pentabrominated diphenyl ethers mixture (DE-71) at concentrations of 0, 0.32, 3.58, and 31.0 µg/L until 15 d postfertilization. The authors then assessed photoreceptor opsin expression, retinal histology, and visual behavior of the larvae. The results showed that the transcriptions of the opsin genes, zfrho and zfgr1, were significantly upregulated. Western blotting further demonstrated a significant increase in rhodopsin protein expression after exposure of the larvae to DE-71. Histological examination revealed the following morphological alterations in the retina: increased area of inner nuclear layer, decreased area of inner plexiform layer, and decreased density of ganglion cells. Tests of optokinetic and phototactic behavior showed hyperactive responses on exposure to DE-71, including increased saccadic eye movements and phototactic response. The present study is the first to demonstrate that the acute exposure of zebrafish larvae to DE-71 causes biochemical and structural changes in the eye that lead to behavioral alterations. Analysis of these visual behavioral paradigms may be useful in predicting the adverse effects of toxicants on visual function in fish.
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Affiliation(s)
- Lianguo Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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61
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Johnson LL, Anulacion BF, Arkoosh MR, Burrows DG, da Silva DA, Dietrich JP, Myers MS, Spromberg J, Ylitalo GM. Effects of Legacy Persistent Organic Pollutants (POPs) in Fish—Current and Future Challenges. FISH PHYSIOLOGY 2013. [DOI: 10.1016/b978-0-12-398254-4.00002-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Kiciński M, Viaene MK, Den Hond E, Schoeters G, Covaci A, Dirtu AC, Nelen V, Bruckers L, Croes K, Sioen I, Baeyens W, Van Larebeke N, Nawrot TS. Neurobehavioral function and low-level exposure to brominated flame retardants in adolescents: a cross-sectional study. Environ Health 2012; 11:86. [PMID: 23151181 PMCID: PMC3519795 DOI: 10.1186/1476-069x-11-86] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/29/2012] [Indexed: 05/21/2023]
Abstract
BACKGROUND Animal and in vitro studies demonstrated a neurotoxic potential of brominated flame retardants, a group of chemicals used in many household and commercial products to prevent fire. Although the first reports of detrimental neurobehavioral effects in rodents appeared more than ten years ago, human data are sparse. METHODS As a part of a biomonitoring program for environmental health surveillance in Flanders, Belgium, we assessed the neurobehavioral function with the Neurobehavioral Evaluation System (NES-3), and collected blood samples in a group of high school students. Cross-sectional data on 515 adolescents (13.6-17 years of age) was available for the analysis. Multiple regression models accounting for potential confounders were used to investigate the associations between biomarkers of internal exposure to brominated flame retardants [serum levels of polybrominated diphenyl ether (PBDE) congeners 47, 99, 100, 153, 209, hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA)] and cognitive performance. In addition, we investigated the association between brominated flame retardants and serum levels of FT3, FT4, and TSH. RESULTS A two-fold increase of the sum of serum PBDE's was associated with a decrease of the number of taps with the preferred-hand in the Finger Tapping test by 5.31 (95% CI: 0.56 to 10.05, p = 0.029). The effects of the individual PBDE congeners on the motor speed were consistent. Serum levels above the level of quantification were associated with an average decrease of FT3 level by 0.18 pg/mL (95% CI: 0.03 to 0.34, p = 0.020) for PBDE-99 and by 0.15 pg/mL (95% CI: 0.004 to 0.29, p = 0.045) for PBDE-100, compared with concentrations below the level of quantification. PBDE-47 level above the level of quantification was associated with an average increase of TSH levels by 10.1% (95% CI: 0.8% to 20.2%, p = 0.033), compared with concentrations below the level of quantification. We did not observe effects of PBDE's on neurobehavioral domains other than the motor function. HBCD and TBBPA did not show consistent associations with performance in the neurobehavioral tests. CONCLUSIONS This study is one of few studies and so far the largest one investigating the neurobehavioral effects of brominated flame retardants in humans. Consistently with experimental animal data, PBDE exposure was associated with changes in the motor function and the serum levels of the thyroid hormones.
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Affiliation(s)
- Michał Kiciński
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Mineke K Viaene
- Department of Neurology, Sint Dimphna Hospital, Geel, Belgium
| | - Elly Den Hond
- Flemish Institute for Technological Research, Environmental Risk and Health, Mol, Belgium
| | - Greet Schoeters
- Flemish Institute for Technological Research, Environmental Risk and Health, Mol, Belgium
- Department of Biomedical sciences, University of Antwerp, Antwerp, Belgium
| | - Adrian Covaci
- Toxicological Center, University of Antwerp, Antwerp, Belgium
| | - Alin C Dirtu
- Toxicological Center, University of Antwerp, Antwerp, Belgium
| | - Vera Nelen
- Department of Health, Provincial Institute for Hygiene, Antwerp, Belgium
| | - Liesbeth Bruckers
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium
| | - Kim Croes
- Department of Analytical and Environmental Chemistry, Brussels Free University (VUB), Brussels, Belgium
| | - Isabelle Sioen
- Department of Public Health, Ghent University, Ghent, Belgium
| | - Willy Baeyens
- Department of Analytical and Environmental Chemistry, Brussels Free University (VUB), Brussels, Belgium
| | - Nicolas Van Larebeke
- Department of Radiotherapy and Nuclear Medicine, University Ghent, Ghent, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
- School of Public Health, Occupational and Environmental Medicine, KULeuven, Leuven, Belgium
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63
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Klosterhaus SL, Stapleton HM, La Guardia MJ, Greig DJ. Brominated and chlorinated flame retardants in San Francisco Bay sediments and wildlife. ENVIRONMENT INTERNATIONAL 2012; 47:56-65. [PMID: 22766500 DOI: 10.1016/j.envint.2012.06.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/10/2012] [Accepted: 06/13/2012] [Indexed: 06/01/2023]
Abstract
Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the use of alternative flame retardants in consumer products to comply with flammability standards. In contrast to PBDEs, information on the occurrence and fate of these alternative compounds in the environment is limited, particularly in the United States. In this study, a survey of flame retardants in San Francisco Bay was conducted to evaluate whether PBDE replacement chemicals and other current use flame retardants were accumulating in the Bay food web. In addition to PBDEs, brominated and chlorinated flame retardants (hexabromocyclododecane (HBCD) and Dechlorane Plus (DP)) were detected in Bay sediments and wildlife. Median concentrations of PBDEs, HBCD, and DP, respectively, were 4.3, 0.3, and 0.2 ng g⁻¹ dry weight (dw) in sediments; 1670, <6.0, and 0.5 ng g⁻¹ lipid weight (lw) in white croaker (Genyonemus lineatus); 1860, 6.5, and 1.3 ng g⁻¹ lw in shiner surfperch (Cymatogaster aggregata); 5500, 37.4, and 0.9 ng g⁻¹ lw in eggs of double-crested cormorant (Phalacrocorax auritus); 770, 7.1, and 0.9 ng g⁻¹ lw in harbor seal (Phoca vitulina) adults; and 330, 3.5, and <0.1 ng g⁻¹ lw in harbor seal (P. vitulina) pups. Two additional flame retardants, pentabromoethylbenzene (PBEB) and 1,2-bis(2,4,6 tribromophenoxy)ethane (BTBPE) were detected in sediments but with less frequency and at lower concentrations (median concentrations of 0.01 and 0.02 ng g⁻¹ dw, respectively) compared to the other flame retardants. PBEB was also detected in each of the adult harbor seals and in 83% of the pups (median concentrations 0.2 and 0.07 ng g⁻¹ lw, respectively). The flame retardants hexabromobenzene (HBB), decabromodiphenyl ethane (DBDPE), bis(2-ethylhexyl) tetrabromophthalate (TBPH), and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), were not detected in sediments and BTBPE, HBB and TBB were not detected in wildlife samples. Elevated concentrations of some flame retardants were likely associated with urbanization and Bay hydrodynamics. Compared to other locations, concentrations of PBDEs in Bay wildlife were comparable or higher, while concentrations of the alternatives were generally lower. This study is the first to determine concentrations of PBDE replacement products and other flame retardants in San Francisco Bay, providing some of the first data on the food web occurrence of these flame retardants in a North American urbanized estuary.
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Affiliation(s)
- Susan L Klosterhaus
- San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804, USA.
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Chen L, Huang C, Hu C, Yu K, Yang L, Zhou B. Acute exposure to DE-71: effects on locomotor behavior and developmental neurotoxicity in zebrafish larvae. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2012; 31:2338-2344. [PMID: 22833361 DOI: 10.1002/etc.1958] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/04/2012] [Accepted: 06/12/2012] [Indexed: 06/01/2023]
Abstract
The aim of the present study was to investigate the acute developmental neurotoxicity of polybrominated diphenyl ethers (PBDEs) in zebrafish larvae. From 2 to 120 h postfertilization zebrafish embryos were exposed to DE-71 (0, 31.0, 68.7, and 227.6 µg/L). The authors studied the locomotor behavior of larvae, involvement of the cholinergic system, and selected gene and protein expressions in the central nervous system. The results showed that low DE-71 concentration caused hyperactivity, whereas higher concentrations decreased activity during the dark period. During the light period, larval activity was significantly reduced in a concentration-dependent manner. In the cholinergic system, acetylcholinesterase activity significantly increased (10.7 and 12.4%) in the 68.7 and 227.6 µg/L exposure groups, respectively, and acetylcholine concentration accordingly decreased (60.5%) in the 227.6 µg/L exposure group. The mRNA expressions of genes encoding myelin basic protein, neuron microtubule protein (α1-tubulin), and sonic hedgehog a were significantly downregulated. Western blotting assay demonstrated that the protein concentration of α1-tubulin was also decreased. Overall, the present study demonstrated that acute exposure to PBDEs can disrupt the neurobehavior of zebrafish larvae and affect cholinergic neurotransmission and neuron development.
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Affiliation(s)
- Lianguo Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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65
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Chen X, Huang C, Wang X, Chen J, Bai C, Chen Y, Chen X, Dong Q, Yang D. BDE-47 disrupts axonal growth and motor behavior in developing zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 120-121:35-44. [PMID: 22609740 DOI: 10.1016/j.aquatox.2012.04.014] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 04/20/2012] [Accepted: 04/23/2012] [Indexed: 05/20/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental pollutants detected in a wide variety of environmental matrixes and pose a significant public health concern. 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) is one of the most predominant PBDE congeners in environmental media, biota and human tissues. However, few studies have explored the BDE-47 developmental neurotoxicity and underlying mechanisms. In this study, zebrafish (Danio rerio) embryos were waterborne exposed to BDE-47 at 1.25, 5, 20 μM starting from 6h post-fertilization (hpf). Motor behavior development and swimming behavior in response to light-to-dark photoperiod stimulation were studied at various developmental stages. Our data indicate that BDE-47 exposure significantly affected spontaneous movement, decreased touch response and free swimming speed, altered larvae swimming behavior in response to light stimulation in developing zebrafish. Consistent with these motor deficits, BDE-47 significantly inhibited axonal growth of primary and secondary motor neurons during the early developmental stages, suggesting the functional relevance of structural changes. Our findings demonstrate that the altered patterns of neuronal connectivity may contribute to motor behavior deficits, indicating the relevance of zebrafish as a model for studying toxicant developmental neurotoxicity.
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Affiliation(s)
- Xiaojuan Chen
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou 325035, China
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66
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Chiu JMY, Po BHK, Chan CYS, Lam MHW, Qian PY, Wu RSS. Polybrominated diphenyl ethers (PBDEs) alter larval settlement of marine intertidal organisms across three phyla via reducing bacterial abundance on the biofilms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:7772-7781. [PMID: 22697365 DOI: 10.1021/es300261c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants over the last three decades, and are now ubiquitous in the marine environment. While the harmful effects of PBDEs on the abnormal development and reproductive impairment in mammals and fish are well documented, the effects on marine invertebrates remain virtually unknown. Using three model intertidal species accross three phyla, including the polychaete Hydroides elegans (Phylum Annelida), the gastropod Crepidula onyx (Phylum Mollusca), and the barnacle Balanus amphitrite (Phylum Arthopoda), this study demonstrated that (a) chronic exposure to BDE-47 (at spiking concentrations up to 1000 ng L(-1)) throughout the entire larval stage did not affect settlement, development or growth of all three species per se, despite bioaccumulation was clearly evident (measured body burden ranging from approximately 7000 to 13 000 ng BDE-47 g(-1) lipid), and (b) BDE-47, at measured concentrations of 15 and 113 ng g(-1) lipid, reduced the bacterial abundance in biofilms and resulted in a concomitant change in larval settlement pattern of all the model intertidal species across three phyla.
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Affiliation(s)
- Jill M Y Chiu
- Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong SAR, China.
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67
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Mechanistic and kinetic study on the reaction of 2;4-dibrominated diphenyl ether (BDE-7) with OH radicals. COMPUT THEOR CHEM 2012. [DOI: 10.1016/j.comptc.2011.12.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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68
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McClain V, Stapleton HM, Gallagher E. BDE 49 and developmental toxicity in zebrafish. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:253-8. [PMID: 21951712 PMCID: PMC3246048 DOI: 10.1016/j.cbpc.2011.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/08/2011] [Accepted: 09/09/2011] [Indexed: 12/01/2022]
Abstract
The polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants. Human health concerns of these agents have largely centered upon their potential to elicit reproductive and developmental effects. Of the various congeners, BDE 49 (2,2',4,5'-tetrabromodiphenyl ether) has been poorly studied, despite the fact that it is often detected in the tissues of fish and wildlife species. Furthermore, we have previously shown that BDE 49 is a metabolic debromination product of BDE 99 hepatic metabolism in salmon, carp and trout, underscoring the need for a better understanding of biological effects. In the current study, we investigated the developmental toxicity of BDE 49 using the zebrafish (Danio rerio) embryo larval model. Embryo and larval zebrafish were exposed to BDE 49 at either 5 hours post fertilization (hpf) or 24 hpf and monitored for developmental and neurotoxicity. Exposure to BDE 49 at concentrations of 4iμ-32 μM caused a dose-dependent loss in survivorship at 6 days post fertilization (dpf). Morphological impairments were observed prior to the onset of mortality, the most striking of which included severe dorsal curvatures of the tail. The incidence of dorsal tail curvatures was dose and time dependent. Exposure to BDE 49 caused cardiac toxicity as evidenced by a significant reduction in zebrafish heart rates at 6 dpf but not earlier, suggesting that cardiac toxicity was non-specific and associated with physiological stress. Neurobehavioral injury from BDE 49 was evidenced by an impairment of touch-escape responses observed at 5 dpf. Our results indicate that BDE 49 is a developmental toxicant in larval zebrafish that can cause morphological abnormalities and adversely affect neurobehavior. The observed toxicities from BDE 49 were similar in scope to those previously reported for the more common tetrabrominated congener, BDE 47, and also for other lower brominated PBDEs, suggest that these compounds may share similarities in risk to aquatic species.
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Affiliation(s)
- Valerie McClain
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle WA 98105-6099, USA
| | | | - Evan Gallagher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle WA 98105-6099, USA
- Address correspondence to: Dr. Evan P. Gallagher, Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way Northeast, Suite 100, Seattle, WA 98105-6099, USA, , Telephone: 206 616 4739; Fax: 206 685 4696
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69
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Mhadhbi L, Fumega J, Boumaiza M, Beiras R. Acute toxicity of polybrominated diphenyl ethers (PBDEs) for turbot (Psetta maxima) early life stages (ELS). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2012; 19:708-717. [PMID: 21912957 DOI: 10.1007/s11356-011-0602-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 08/29/2011] [Indexed: 05/31/2023]
Abstract
BACKGROUND, AIM AND SCOPE The environmental presence of polybrominated diphenyl ethers (PBDEs), among which BDE-47 and BDE-99 are particularly abundant, makes toxicity data necessary to assess the hazard risk posed by PBDE to aquatic organisms. This study examines the effects of BDE-47 and BDE-99 on embryo-larval stages of the marine flatfish turbot. MATERIALS AND METHODS The turbot embryos were exposed at nominal concentrations of BDE-47 and BDE-99 for 6 days. Selected dose levels were relevant for investigating sublethal and lethal effects. RESULTS Both tested compounds caused lethal toxicity as well as non-lethal malformations during embryo development. We found a high toxic potency of BDE-47 compared to BDE-99 (LC₅₀ values for embryos and larvae, respectively, BDE-47: 27.35 and 14.13 μg L⁻¹; BDE-99: 38.28 and 29.64 μg L⁻¹). DISCUSSION The present study shows high sensitivity of fish early life stages (ELS) to PBDE compounds. Based on environmental concentrations of dissolved PBDEs from various aquatic ecosystems, waterborne BDE-47 and BDE-99 pose little risk of acute toxicity to marine fish at relevant environmental concentrations. CONCLUSIONS Turbot fish ELS proved to be an excellent model for the study of ecotoxicity of contaminants in seawater. The results demonstrate harmful effects of PBDE on turbot ELS at concentrations in the range of parts per billion units. RECOMMENDATIONS AND PERSPECTIVES In the perspective of risk assessment, ELS endpoints provide rapid, cost-effective and ecologically relevant information, and links should be sought between these short-term tests and effects of long-term exposures in more realistic scenarios.
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Affiliation(s)
- Lazhar Mhadhbi
- Toralla Marine Science Station (ECIMAT), University of Vigo, 36331 Vigo, Galicia, Spain.
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70
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Van Schmidt ND, Cary TL, Ortiz-Santaliestra ME, Karasov WH. Effects of chronic polybrominated diphenyl ether exposure on gonadal development in the northern leopard frog, Rana pipiens. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2012; 31:347-354. [PMID: 22105220 DOI: 10.1002/etc.1702] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are bioaccumulative, persistent organic pollutants used as flame retardants in consumer goods. Concentrations of PBDEs in North American wildlife have been increasing for decades and been shown to have estrogenic effects on sexual development. No studies, however, have examined the effects of PBDEs on the sexual development of North American frogs at ecologically relevant concentrations. This study examined the effects of five dietary concentrations of DE-71 (0, 1.1, 6.1, 71.4, and 634 ng ΣPBDEs/g diet), a technical PBDE mixture, on the gonadal development of the northern leopard frog, Rana pipiens. Tadpoles were exposed chronically from the time they became free-swimming until metamorphosis. Frogs were killed either at metamorphic climax or 10 weeks after completing metamorphosis, processed for histology, and examined for alterations in sexual development. The experimental group exposed to PBDEs at 1.1 ng/g had a significantly larger proportion of females compared with the expected 50:50 sex ratio. At 10 weeks post-metamorphosis, male frogs exposed to 6.1 and 71.4 ng/g had significantly smaller testes, but all other measure of gonadal development tested showed no effects. No intersex or increased incidence of gonadal abnormality were detected. These findings indicate that PBDEs may disrupt sexual differentiation in frogs at low, environmentally relevant concentrations.
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Affiliation(s)
- Nathan D Van Schmidt
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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71
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He J, Yang D, Wang C, Liu W, Liao J, Xu T, Bai C, Chen J, Lin K, Huang C, Dong Q. Chronic zebrafish low dose decabrominated diphenyl ether (BDE-209) exposure affected parental gonad development and locomotion in F1 offspring. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:1813-1822. [PMID: 21695510 DOI: 10.1007/s10646-011-0720-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/15/2011] [Indexed: 05/30/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants around the world. Because of large production volumes, widespread usage and persistence, PBDEs are now ubiquitous environmental pollutants detected in a wide variety of environment media and human samples and therefore pose a significant public health concern. Deca-PBDE (BDE-209) is the only commercial PBDE mixture still allowed for use at present, and has been recently detected at high levels in human samples. However, few studies explore its effect on development, reproduction or neurobehavior with animal models. In particular, studies with long-term chronic exposure at relatively low doses are lacking. In this study, we utilize the zebrafish model to explore the developmental, reproductive, and behavioral toxicities associated with long-term chronic exposure to deca-PBDE (BDE-209). Our findings revealed that long-term chronic exposure to low dose of deca-BDE (ranging from 0.001 to 1 μM) affected overall fitness (measured by condition factor), gonad development, male gamete quantity and quality in F0 parental fish. For F1 offspring without continuous exposure to BDE-209, parental BDE treatment led to delayed hatch and motor neuron development, loose muscle fiber, slow locomotion behavior in normal conditions, and hyperactivity when subjected to light-dark photoperiod stimulation. In conclusion, parental chronic low dose BDE-209 exposure not only affects F0 growth and reproduction, but also elicits neurobehavior alternations in F1 offspring.
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Affiliation(s)
- Jianhui He
- Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou, 325035, People's Republic of China
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72
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Usenko CY, Robinson EM, Usenko S, Brooks BW, Bruce ED. PBDE developmental effects on embryonic zebrafish. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:1865-72. [PMID: 21560146 DOI: 10.1002/etc.570] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 02/15/2011] [Accepted: 04/14/2011] [Indexed: 05/22/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental contaminants with potential for bioaccumulation and maternal-fetal transfer that has led to regulatory bans and/or phasing out of several technical mixtures of PBDEs. In the present study, six PBDE congeners (BDE 28, BDE 47, BDE 99, BDE 100, BDE 153, BDE 183) were evaluated for developmental effects on embryonic zebrafish. These congeners were chosen because they are environmentally relevant and cover a wide range of physical-chemical properties. Alterations in behavior, physical malformations, and mortality were scored daily until 168 h postfertilization (hpf). A concentration-dependent increase in spontaneous movement indicated an early onset of behavioral responses to PBDE exposures. Spontaneous movement was affected the most by BDE 47 and BDE 28, whereas BDE 183 did not alter behavior at any concentration tested. Swimming rates were significantly increased by BDE 28 at 96 and 120 hpf, but decreased swimming activity at 168 hpf. Additionally, BDE 47 significantly decreased the swimming rate at 168 hpf. Other endpoints included malformations and mortality. Congeners with fewer bromines (BDE 28, 47, 99, and 100) also induced a curved body axis starting around 120 hpf, which was followed by mortality. BDEs 153 and 183, however, did not elicit these adverse effects. A relationship was found between log K(OW) and median lethal concentration (LC50) and median effective concentration (EC50). Structure-activity relationships in this study suggest that PBDE acute toxicity results from a receptor-mediated effect and further studies are necessary to determine these pathways.
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73
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Noyes PD, Hinton DE, Stapleton HM. Accumulation and debromination of decabromodiphenyl ether (BDE-209) in juvenile fathead minnows (Pimephales promelas) induces thyroid disruption and liver alterations. Toxicol Sci 2011; 122:265-74. [PMID: 21546348 PMCID: PMC3155082 DOI: 10.1093/toxsci/kfr105] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 04/28/2011] [Indexed: 11/12/2022] Open
Abstract
Polybrominated diphenyl ether (PBDE) flame retardants are known to affect thyroid hormone (TH) regulation. The TH-regulating deiodinases have been implicated in these impacts; however, PBDE effects on the fish thyroid system are largely unknown. Moreover, the liver as a potential target of PBDE toxicity has not been explored in young fish. This study measured decabromodiphenyl ether (BDE-209) effects on TH regulation by measuring deiodinase activity in juvenile fathead minnows (Pimephales promelas). Dietary accumulations and debromination of BDE-209 were also measured, and the morphology of thyroid and liver tissues was examined. Juvenile fathead minnows (28 days old) received a 28-day dietary treatment of BDE-209 at 9.8 ± 0.16 μg/g of food at 5% of their body weight per day followed by a 14-day depuration period in which they were fed clean food. Chemical analysis revealed that BDE-209 accumulated in tissues and was metabolized to reductive products ranging from penta- to octaBDEs with 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154) being the most accumulative metabolite. By day 28 of the exposure, rates of outer and inner ring deiodination (ORD and IRD, respectively) of thyroxine (T4) were each reduced by ∼74% among treatments. Effects on T4-ORD and T4-IRD remained significant even after the 14-day depuration period. Histological examination of treated fish showed significantly increased thyroid follicular epithelial cell heights and vacuolated hepatocyte nuclei. Enlarged biliary passageways may be the cause of the distinctive liver phenotype observed, although further testing is needed. Altogether, these results suggest that juvenile fish may be uniquely susceptible to thyroid disruptors like PBDEs.
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Affiliation(s)
| | | | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708
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74
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Chen TH, Lin CY, Tseng MC. Behavioral effects of titanium dioxide nanoparticles on larval zebrafish (Danio rerio). MARINE POLLUTION BULLETIN 2011; 63:303-308. [PMID: 21565364 DOI: 10.1016/j.marpolbul.2011.04.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 01/26/2011] [Accepted: 04/12/2011] [Indexed: 05/30/2023]
Abstract
In this study, zebrafish embryos were exposed to titanium dioxide nanoparticles (TiO2 NPs at 0.1, 0.5, 1, 5, 10 mg/L or control) from fertilization to free swimming stage. Hatchability, survival, and malformation rate were not affected by TiO2 NPs at these exposure levels. However, larval swimming parameters, including average and maximum velocity and activity level were significantly affected by TiO2 NPs. Co-exposure to either the glutathione precursor, N-acetylcysteine (NAC), or the glutathione synthesis inhibitor, buthionine sulfoximine (BSO), did not significantly alter the behavioral effects resulting from TiO2 NPs, suggesting that other factor(s) besides oxidative stress may contribute to the behavioral toxicity of TiO2 NPs. Our study also demonstrated that the behavioral endpoints were more sensitive than the others (e.g., hatchability and survival) to detect toxicity of TiO2 NPs on developing fish.
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Affiliation(s)
- Te-Hao Chen
- Department of Biology, National Museum of Marine Biology and Aquarium, Pingtung, Taiwan.
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75
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Chen TH, Wang YH, Wu YH. Developmental exposures to ethanol or dimethylsulfoxide at low concentrations alter locomotor activity in larval zebrafish: implications for behavioral toxicity bioassays. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2011; 102:162-166. [PMID: 21356178 DOI: 10.1016/j.aquatox.2011.01.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 01/14/2011] [Accepted: 01/27/2011] [Indexed: 05/30/2023]
Abstract
Ethanol and dimethylsulfoxide (DMSO) are commonly used as carrier solvents for lipophilic chemicals in aquatic toxicity bioassays. However, very little information has been reported on the behavioral effects of these solvents. In this study, we examined the effects of ethanol and DMSO on development and locomotor activity by a zebrafish embryo-larval bioassay. The zebrafish were exposed to different concentrations (control, 0.01, 0.1, and 1%) of ethanol or DMSO from blastula stage to 144 hour-post-fertilization (hpf). Hatchability, survival, and abnormalities were monitored every 12h, and locomotor activity of the larvae was analyzed at 144 hpf. Hatchability was not affected by the ethanol or DMSO treatments. No effect on survival was observed except the 1% ethanol group suffered 89% mortality during 108-120 hpf. No developmental defects were observed in any of the solvents at the 0.01 and 0.1% concentrations, but significantly higher deformity rates occurred with 1% ethanol and DMSO groups. Hyperactivity and less tortuous swimming paths were observed in all ethanol and DMSO concentrations. Based on this study, we suggest that data of behavioral toxicity bioassays using ethanol or DMSO as carrier solvents should be interpreted cautiously, because the solvents at low concentrations could alter locomotor activity of larval zebrafish without causing any observable developmental defects.
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Affiliation(s)
- Te-Hao Chen
- Department of Biology, National Museum of Marine Biology and Aquarium, Checheng, Pingtung, Taiwan, ROC.
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76
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Shaw SD, Blum A, Weber R, Kannan K, Rich D, Lucas D, Koshland CP, Dobraca D, Hanson S, Birnbaum LS. Halogenated flame retardants: do the fire safety benefits justify the risks? REVIEWS ON ENVIRONMENTAL HEALTH 2010; 25:261-305. [PMID: 21268442 DOI: 10.1515/reveh.2010.25.4.261] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Since the 1970s, an increasing number of regulations have expanded the use of brominated and chlorinated flame retardants. Many of these chemicals are now recognized as global contaminants and are associated with adverse health effects in animals and humans, including endocrine and thyroid disruption, immunotoxicity, reproductive toxicity, cancer, and adverse effects on fetal and child development and neurologic function. Some flame retardants such as polybrominated diphenyl ethers (PBDEs) have been banned or voluntarily phased out by manufacturers because of their environmental persistence and toxicity, only to be replaced by other organohalogens of unknown toxicity. Despite restrictions on further production in some countries, consumer products previously treated with banned retardants are still in use and continue to release toxic chemicals into the environment, and the worldwide use of organohalogen retardants continues to increase. This paper examines major uses and known toxic effects of commonly-used organohalogen flame retardants, replacements for those that have been phased out, their combustion by-products, and their effectiveness at reducing fire hazard. Policy and other solutions to maintain fire safety while reducing toxicity are suggested. The major conclusions are: (1) Flammability regulations can cause greater adverse environmental and health impacts than fire safety benefits. (2) The current options for end-of-life disposal of products treated with organohalogens retardants are problematic. (3) Life-cycle analyses evaluating benefits and risks should consider the health and environmental effects of the chemicals, as well as their fire safety impacts. (4) Most fire deaths and most fire injuries result from inhaling carbon monoxide, irritant gases, and soot. The incorporation of organohalogens can increase the yield of these toxic by-products during combustion. (5) Fire-safe cigarettes, fire-safe candles, child-resistant lighters, sprinklers, and smoke detectors can prevent fires without the potential adverse effects of flame retardant chemicals. (6) Alternatives to organohalogen flame retardant chemicals include using less flammable materials, design changes, and safer chemicals. To date, before evaluating their health and environmental impacts, many flame retardant chemicals have been produced and used, resulting in high levels of human exposure. As a growing literature continues to find adverse impacts from such chemicals, a more systematic approach to their regulation is needed. Before implementing new flammability standards, decision-makers should evaluate the potential fire safety benefit versus the health and environmental impacts of the chemicals, materials, or technologies likely to be used to meet the standard. Reducing the use of toxic or untested flame retardant chemicals in consumer products can protect human and animal health and the global environment without compromising fire safety.
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Affiliation(s)
- Susan D Shaw
- Marine Environmental Research Institute, Center for Marine Studies, Blue Hill, ME 04614, USA.
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