| 1. |
- Arnoldsson, Kristina, 1961-, et al.
(författare)
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Retention and maternal transfer of environmentally relevant polybrominated dibenzo-p-dioxins and dibenzofurans, polychlorinated dibenzo-p-dioxins and dibenzofurans, and polychlorinated biphenyls in zebrafish (Danio rerio) after dietary exposure
- 2012
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Ingår i: Environmental Toxicology and Chemistry. - : John Wiley & Sons. - 0730-7268 .- 1552-8618. ; 31:4, s. 804-812
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Tidskriftsartikel (refereegranskat)abstract
- High levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), mono- and non-ortho polychlorinated biphenyls (PCBs), and polybrominated dibenzo-p-dioxins (PBDDs) are found in fish from coastal areas in the Baltic Sea, which may cause ecotoxicological effects. To increase our understanding of the persistency of the emerging pollutants polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), fish feed was spiked with 21 PBDD/Fs, 17 PCDD/Fs, and 30 PCBs and fed to zebrafish. Concentrations in fish and eggs were examined during a six- or twelve-week uptake period, and a six-week elimination period. Steady-state was reached for 2, 3, 7, and/or 8-substituted tri- and tetra-BDD/Fs, with 2,3,7,8-tetra-BDD (2,3,7,8-TeBDD) being the most strongly retained. Steady-state was not reached for tetra- to hexa-CDDs. Non-2,3,7,8-congeners showed little of or no retention. Most PCBs had high retention and did not reach steady-state. Half-lives decreased in the order: PCBs > PCDD/Fs > PBDD/Fs. Concentrations of 2,3,7,8-penta- to octa-CDD/Fs decreased with their degree of chlorination suggesting that the rate-limiting factor for uptake is low bioavailability. Maternal transfer was observed for all retained compounds, with most transfer factors < 1, indicating that transfer rates are affected by the poor water solubility of the compounds. The limited retention of the major PBDD congeners found in Baltic Sea fish suggests that they are exposed to high or very high concentrations via either food or water.
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| 2. |
- Bergman, Åke, et al.
(författare)
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Science and policy on endocrine disrupters must not be mixed : a reply to a "common sense" intervention by toxicology journal editors
- 2013
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The "common sense" intervention by toxicology journal editors regarding proposed European Union endocrine disrupter regulations ignores scientific evidence and well-established principles of chemical risk assessment. In this commentary, endocrine disrupter experts express their concerns about a recently published, and is in our considered opinion inaccurate and factually incorrect, editorial that has appeared in several journals in toxicology. Some of the shortcomings of the editorial are discussed in detail. We call for a better founded scientific debate which may help to overcome a polarisation of views detrimental to reaching a consensus about scientific foundations for endocrine disrupter regulation in the EU.
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| 3. |
- Carlsson, Gunnar, et al.
(författare)
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Comparison of embryo toxicity using two classes of aquatic vertebrates
- 2014
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Ingår i: Environmental toxicology and pharmacology. - : Elsevier BV. - 1382-6689 .- 1872-7077. ; 37, s. 24-27
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Tidskriftsartikel (refereegranskat)abstract
- Toxicity tests of musk ketone (MK) and tetrabromobisphenol-A (TBBPA) on embryos were conducted in two amphibian species, Xenopus (Silurana) tropicalis and the Swedish native species Rana arualis. TBBPA was also tested on fish embryos of Danio rerio. All species were tested in similar experimental setup. Musk ketone caused decreased heart rates at concentrations from 10 and 100 mu g/L in R. arualis and X. tropicalis, respectively. TBBPA caused effects at 1000 mu g/L in all three species. The responses were comparable between all three species which supports the relevance for using data from non-native species in national risk assessment. (C) 2013 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
- Carlsson, Gunnar, et al.
(författare)
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Toxicity of 15 veterinary Pharmaceuticals in zebrafish (Danio rerio) embryos
- 2013
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 126, s. 30-41
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Tidskriftsartikel (refereegranskat)abstract
- Extensive use of veterinary pharmaceuticals may result in contamination of water bodies adjacent to pasture land or areas where animal manure has been applied. In order to evaluate the potential risk to fish embryos 15 veterinary pharmaceuticals were investigated by use of an extended zebrafish embryo toxicity test. Chemical analysis of the exposure medium was performed by solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for 11 of the compounds and potential metabolism by the embryos was studied for albendazole, febantel, fenbendazole and oxfendazole. Newly fertilized zebrafish eggs were exposed under static conditions in 96-well plates for 6 days to the pharmaceuticals: 5 antibacterials and 10 antiparasitics. Endpoints including mortality, malformations and other sublethal responses were recorded at 24, 48 and 144 h post fertilization (hpf). The pharmaceuticals causing the highest toxicity were antiparasitics whereas the tested antibacterials, danofloxacin, enrofloxacin, tylosine, trimethoprim and oxytetracyclin had a much lower toxic potency in zebrafish embryos. Most toxic were fenbendazole, albendazole and flumethrin with no observed effect concentrations (NOECs) around 0.02 mg/L. The overall NOEC was determined by lethality for the following pharmaceuticals: albendazole, fenbendazole and oxfendazole. Sublethal endpoints, including malformations, side-laying embryos, tremors, reduced movements and altered heart rate increased the sensitivity of the tests and determined the overall NOECs for febantel, doramectin, ivermectin, flumethrin and toltrazuril. Exposure to doramectin and ivermectin caused a decrease in movements at 24 hpf and a decrease in heart rate at 48 hpf. Flumethrin exposure resulted in decreased time to hatching, except at the highest concentrations, and caused an increase in heart rate at 48 hpf. In contrast, toltrazuril caused an increased time to hatching and a decrease in heart rate. Chemical analysis of the exposure medium after the tests revealed great differences between nominal and measured concentrations, emphasizing the need of including analysis of the actual exposure concentrations. The results indicated that metabolism of albendazole into its sulfoxide protected the embryos from toxicity. Albendazole was metabolized efficiently into albendazole sulfoxide at lower exposure concentrations, resulting in reduced toxicity. At higher concentrations, an increasing proportion of albendazole remained unmetabolized and embryo mortality occurred. Metabolism by the embryos of febantel into fenbendazole and oxfendazole and of fenbendazole into oxfendazole was demonstrated. It is suggested that the toxic effect of febantel in zebrafish embryos is due to metabolism into fenbendazole.
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| 6. |
- Carlsson, Gunnar, et al.
(författare)
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Toxicity screening of produced water extracts in a zebrafish embryo assay
- 2014
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Ingår i: Journal of Toxicology and Environmental Health, Part A: Current Issues. - : Informa UK Limited. - 1528-7394 .- 1087-2620. ; 77, s. 600-615
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Tidskriftsartikel (refereegranskat)abstract
- Produced water is the largest effluent discharge from oil and gas/condensate production facilities in the North Sea. There is concern that contaminants originating from the reservoir and chemicals used in the production process may affect marine organisms. Developmental toxicity of extractable organic compounds in produced water effluents from oil and gas/condensate production platforms in the Norwegian sector of the North Sea was assessed in a temporal and spatial manner using zebrafish (Danio rerio) embryos. Large-scale solid-phase extraction (SPE) and on-column fractionation of water-soluble fraction (WSF) and an oil/particulate fraction was used in a rapid screening bioassay for embryotoxicity. Exposure to produced water extracts increased rate of mortality and reduced pigmentation and heart rate, as well as delaying time to hatch. The oil/particulate fraction was 10-fold less toxic than WSF, indicating that toxicity was predominantly produced by moderately polar and bioavailable compounds. Large spatial and temporal variation in produced water toxicity was observed, displaying considerable variability in the reservoir, oil well, and effluent composition over time. The noted toxicity did not correlate well with either reported produced water composition or parameters such as total hydrocarbons, thus challenging chemical measurements as a reliable source of information for predicting complex effects. Although embryotoxicity was observed following exposure to the extracts, dilution and transformation of produced water in the recipient are expected to rapidly reduce the concentrations of compounds in the effluents to levels below the thresholds of observed effects.
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| 7. |
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| 8. |
- Hellström, Anders, et al.
(författare)
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8. Aquaculture and Fish Health
- 2012. - 1
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Ingår i: Ecology and Animal Health. - Uppsala : Baltic University Press. - 9789186189129 ; , s. 63-72
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Bokkapitel (populärvet., debatt m.m.)
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| 9. |
- Holbech, Henrik, et al.
(författare)
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Comparison of zebrafish (Danio rerio) and fathead minnow (Pimephales promelas) as test species in the Fish Sexual Development Test (FSDT).
- 2012
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Ingår i: Comparative Biochemistry and Physiology - Part C. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 155:2, s. 407-15
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Tidskriftsartikel (refereegranskat)abstract
- Results are presented from a validation (with 5 laboratories) of the Fish Sexual Development Test (FSDT) developed to detect endocrine disrupters (EDs) and included in the OECD (Organisation for Economic Co-operation and Development) working program. The aromatase-inhibiting fungicide prochloraz was tested in zebrafish (Danio rerio) and fathead minnow (Pimephales promelas). The fish were exposed during sexual differentiation and development from 0 to 60 days post hatch (dph). After exposure, the vitellogenin (VTG) concentrations were quantified in head/tail homogenate and the sex ratio was determined (defined as female, male, intersex or undifferentiated). NOEC/LOEC and EC(x) designs were compared to optimize the test approach. Results show that both species are highly sensitive to prochloraz during sexual development. They respond by skewing of the sex ratio towards male phenotype and by a VTG decline in females. The NOEC/LOEC approach is preferred because sex ratio is difficult to analyze with a regression model. The mean NOEC/LOEC for prochloraz on the sex ratio was 43.3/134 μg/L and 101/293 μg/L for zebrafish and fathead minnow, respectively. The mean NOEC/LOEC on the decline in female VTG concentration was 65/110 μg/L and ~30/68 μg/L respectively. In conclusion, zebrafish and fathead minnow are suitable species in the FSDT and their sexual differentiation is equally labile to EDs.
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| 10. |
- Jakobsson, Christine, et al.
(författare)
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Preface
- 2012. - 1
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Ingår i: Sustainable Agriculture. - Uppsala : Baltic University Press. - 9789186189105 ; , s. 8-10
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Bokkapitel (populärvet., debatt m.m.)
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| 11. |
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| 12. |
- Ljungvall, Karl, et al.
(författare)
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Sows exposed to octylphenol in early gestation: No estrogenic effects in male piglets, but increased rate of stillbirth
- 2012
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Ingår i: Theriogenology. - : Elsevier BV. - 0093-691X .- 1879-3231. ; 78, s. 1494-1499
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Tidskriftsartikel (refereegranskat)abstract
- Octylphenol is an industrial chemical with estrogenic effects both in vitro and in vivo. In this study the effects of short-term intramuscular exposure to 0.1 mg/kg of body weight and 1.0 mg/kg of body weight in early gestation were evaluated in pregnant sows with respect to reproductive parameters in the newborn male piglets, as compared with male piglets from unexposed control sows. The male piglets were examined immediately after birth with respect to the macroscopic appearance of the reproductive organs and testosterone concentration in serum. It was not possible to identify any estrogenic effects in the newborn male piglets. However, in the sows exposed at the highest level of octylphenol, there was an increased number of stillborn piglets and an increased proportion of sows with stillborn piglets in the litter (P < 0.05). This was an unexpected finding which has not been reported previously. (C) 2012 Elsevier Inc. All rights reserved.
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| 13. |
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| 14. |
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| 15. |
- Norman Haldén, Anna, et al.
(författare)
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Oral exposure of adult zebrafish (Danio rerio) to 2,4,6-tribromophenol affects reproduction
- 2010
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 100, s. 30-37
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Tidskriftsartikel (refereegranskat)abstract
- The bromophenol 2,4,6-tribromophenol (TBP) is widely used as an industrial chemical, formed by degradation of tetrabromobisphenol-A, and it occurs naturally in marine organisms. Concentrations of TBP in fish have been related to intake via feed, but little is known about effects on fish health after oral exposure. In this study, we exposed adult male and female zebrafish (Danio rerio) to TBP via feed in nominal concentrations of 33, 330, and 3300??g/g feed (or control feed) for 6 weeks to assess the effects of TBP on reproductive output, gonad morphology, circulatory vitellogenin levels, and early embryo development. The aim was also to investigate the extent to which TBP was metabolised to 2,4,6-tribromoanisole (TBA) in dietary exposed zebrafish, and the amounts of TBP and TBA found in offspring. After 6 weeks of exposure, we found about 3% of the daily dose of TBP in adult fish and the mean concentration of TBA was 25–30% of the TBP concentration. TBP and TBA were detected in offspring with wet weight-based egg/fish concentration ratios well below one. Exposure to TBP significantly reduced the fertilization success and disturbed the gonad morphology, i.e. fewer spermatid cysts in males and increased presence of atretic follicles and oocytes with decreased vitellogenesis in females. In females, the disturbed gonad morphology was accompanied by increased levels of circulating vitellogenin. Significant effects were observed at 3300??g/g feed. Offspring early development was not significantly affected, but yolk-sac oedema tended to increase in frequency in exposed groups with time. Our results show that dietary exposure to TBP, at concentrations found in marine organisms that are part of the natural diet of wild fish, can interfere with reproduction in zebrafish. We also observed low accumulation from feed of TBP in zebrafish and biotransformation of TBP to TBA. This is the first paper showing gonadal histopathological changes and effects on fertility in TBP exposed fish
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| 16. |
- Norman Haldén, Anna, et al.
(författare)
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Retention and maternal transfer of brominated dioxins in zebrafish (Danio rerio) and effects on reproduction, aryl hydrocarbon receptor-regulated genes, and ethoxyresorufin-O-deethylase (EROD) activity
- 2011
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Ingår i: Aquatic Toxicology. - Oxford : Elsevier. - 0166-445X .- 1879-1514. ; 102:3-4, s. 150-161
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Tidskriftsartikel (refereegranskat)abstract
- Brominated dioxins have recently been detected in Baltic Sea biota. Due to their similarities to the highly toxic chlorinated dioxins, concern has been raised about their potential biological effects. The present study investigated retention and effects of brominated dioxins in adult zebrafish, as well as maternal transfer and effects on offspring. We exposed adult zebrafish for nine weeks via feed to 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) or to a mixture of brominated dioxins (Baltic Sea mixture), which was designed to reflect relative concentrations found in Baltic Sea biota. We studied spawning success, gonad morphology, hepatic vitellogenin gene expression, and offspring early life-stage development to investigate effects on zebrafish reproduction. Hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic expression of a number of aryl hydrocarbon receptor (AHR)-regulated genes were studied to investigate if the brominated dioxins can activate gene transcription through the AHR pathway in zebrafish. In addition, glutathione reductase activity and expression of genes involved in adaptive responses to intracellular stress were studied to investigate potential stress effects of brominated dioxins. After nine weeks of exposure, all brominated dioxins spiked to the feed were detected in female fish and transferred to eggs. Exposure to the Baltic Sea mixture and TBDD clearly induced AHR-regulated genes and EROD activity. Exposure to TBDD reduced spawning success, altered ovarian morphology and reduced hepatic vitellogenin gene expression, which implies that TBDD has a similar effect pattern as the chlorinated analogue. Overall, our results show that dietary exposure to sublethal concentrations of brominated dioxins may impair reproductive physiology in fish and induce AHR-regulated genes. (C) 2011 Elsevier B.V. All rights reserved.
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| 17. |
- Norrgren, Leif
(författare)
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33. Remediation of Lake Järnsjön, Sweden
- 2012. - 2
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Ingår i: Ecology and Animal Health. - Uppsala : Baltic University Press. - 9789186189129 ; , s. 265-267
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Bokkapitel (populärvet., debatt m.m.)
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| 18. |
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| 19. |
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| 20. |
- Ul haq, Mazhar, et al.
(författare)
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Comparison of developmental toxicity of seven perfluoroalkyl acids to zebrafish embryos
- 2013
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Ingår i: Environmental toxicology and pharmacology. - : Elsevier BV. - 1382-6689 .- 1872-7077. ; 36, s. 423-426
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Tidskriftsartikel (refereegranskat)abstract
- The toxicity of individual perfluoroalkyl acids (PFAAs) has been suggested to be determined by the carbon chain length as well as the functional group attached. We tested seven different PFAAs including both sulfonic and carboxylic PFAAs with different chain length to evaluate the developmental toxicity in zebrafish embryos. Generally, the acute toxicity of PFAAs is relatively low to zebrafish embryos. The EC50 values ranged from 1.5 to 2200 mg/L. We observed a relationship between higher toxicity with longer carbon chain. In addition, we also observed a higher toxicity for sulfonic PFAAs than for carboxylic PFAAs. (C) 2013 Elsevier B.V. All rights reserved.
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| 21. |
- Ul haq, Mazhar, et al.
(författare)
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Locomotor behavior in zebrafish (Danio rerio) larvae exposed to perfluoroalkyl acids
- 2013
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 144, s. 332-340
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Tidskriftsartikel (refereegranskat)abstract
- Perfluoroalkyl acids (PFAAs) are persistent organic contaminants that have been detected in wildlife, humans and the environment. Studies have shown that the toxicity of PFAAs is determined by the carbon chain length as well as the attached functional group. The locomotor activity of zebrafish larvae has become widely used for evaluation of chemicals with neurotoxic properties. In the present study the behavioral effects of seven structurally different PFAAs (i.e. TFAA, PFBA, PFOA, PFNA, PFDA, PFBS and PFOS) were evaluated in zebrafish larvae. Exposure to high concentrations of TFAA, PFNA, PFBS and PFOS resulted in distinct changes in behavioral patterns. Based on redundancy analysis, our results demonstrate three main factors affecting zebrafish larval locomotor behavior. The strongest effect on behavior was determined by the carbon chain length and the attached functional group. PFAAs with longer carbon chain length as well as PFAAs with attached sulfonic groups showed larger potential to affect locomotor behavior in zebrafish larvae. Also the concentration of the PFAAs determined the behavior responses. The results of the present study are in agreement with previous studies showing correlations between the chemical structure of PFAAs and the toxicological effects. (C) 2013 Elsevier B.V. All rights reserved.
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| 22. |
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| 23. |
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| 24. |
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