| 1. |
- Nordén, Marcus, 1982-, et al.
(author)
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Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver
- 2012
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In: Environmental Science and Pollution Research. - Heidelberg, Germany : Springer Berlin/Heidelberg. - 0944-1344 .- 1614-7499. ; 19:5, s. 1859-1863
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Journal article (peer-reviewed)abstract
- Purpose: Perfluorooctane sulfonate (PFOS) belongs to a group of chemicals called perfluoroalkyl acids that have been extensively used in various applications such as stain and oil resistant treatments for fabrics, fire-fighting foams, and insecticides. These chemicals present an environmental and health risk being present in many samples both in wildlife and humans. In this study, we investigate the effect of PFOS on fatty acid β-oxidation in developing chicken embryos.Methods: Fertilized chicken eggs were exposed in ovo to PFOS at day 4 of incubation. On day 10, the eggs were dissected and livers were incubated in vitro with (3)H-palmitic acid for 2 h. The media were collected, and after clean up, the amount of tritiated water was measured with liquid scintillation counting to determine the rate of palmitic acid β-oxidation.Results: PFOS was found to induce fatty acid β-oxidation at doses starting from a lowest observed effect level (LOEL) of 0.1 μg/g egg weight. Maximum induction of 77 % compared to control was seen at 0.3 μg/g.Conclusions: The administered doses in which effects are seen are around and even lower than the levels that can be found in wild populations of birds. General population human levels are a factor of two to three times lower than the LOEL value of this study. The environmental contamination of PFOS therefore presents a possibility of effects in wild populations of birds.
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| 2. |
- Eichbaum, Kathrin, et al.
(author)
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In vitro bioassays for detecting dioxin-like activity : Application potentials and limits of detection, a review
- 2014
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In: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 487, s. 37-48
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Journal article (peer-reviewed)abstract
- Use of in vitro assays as screening tool to characterize contamination of a variety of environmental matrices has become an increasingly popular and powerful toolbox in the field of environmental toxicology.While bioassays cannot entirely substitute analytical methods such as gas chromatography-mass spectrometry (GC-MS), the increasing improvement of cell lines and standardization of bioassay procedures enhance their utility as bioanalytical pre-screening tests prior to more targeted chemical analytical investigations. Dioxin-receptor-based assays provide a holistic characterization of exposure to dioxin-like compounds (DLCs) by integrating their overall toxic potential, including potentials of unknown DLCs not detectable via e.g. GC-MS. Hence, they provide important additional information with respect to environmental risk assessment of DLCs.This review summarizes different in vitro bioassay applications for detection of DLCs and considers the comparability of bioassay and chemical analytically derived toxicity equivalents (TEQs) of different approaches and various matrices. These range from complex samples such as sediments through single reference to compound mixtures. A summary of bioassay derived detection limits (LODs) showed a number of current bioassays to be equally sensitive as chemical methodologies, but moreover revealed that most of the bioanalytical studies conducted to date did not report their LODs, which represents a limitation with regard to low potency samples.
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| 3. |
- Eichbaum, Kathrin, et al.
(author)
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The dioRAMA project : assessment of dioxin-like activity in sediments and fish (Rutilus rutilus) in support of the ecotoxicological characterization of sediments
- 2013
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In: Journal of Soils and Sediments. - : Springer. - 1439-0108 .- 1614-7480. ; 13:4, s. 770-774
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Journal article (peer-reviewed)abstract
- Introduction: Given the complex interactions of re-suspension processes and bioavailability of sediment-bound pollutants such as dioxin-like chemicals, there is need for a better integrative understanding of the cause-effect relationship of these pollutants. Currently, the majority of studies investigating potential risks of these chemicals only focus on characterizing sediment extracts via in vitro bioassays, thereby disregarding bioavailability, uptake, metabolism, and elimination rates of these compounds in vivo. To determine to which extent mechanism-specific effects in vitro reflect possible adverse effects in vivo, the research project dioRAMA, involving partnership between the Institute for Environmental Research of RWTH Aachen University and the Department Biochemistry/Ecotoxicology of the German Federal Institute of Hydrology, was established.Methods: Animals from an elevated trophic level-common roach (Rutilus rutilus)-will be exposed to sediments from two major German rivers. Exposure will be performed in a system that enables a concurrent monitoring of environmental parameters. In parallel, in vitro studies will be conducted to determine dioxin-like potentials of sediment and fish extracts from the in vivo exposure experiments using different cell lines with varying endpoints. Moreover, extract fractionation procedures, using the strategy of effect-directed analysis, will enable the detection of specific contaminant groups responsible for the biological activity observed.Conclusion: A closer interconnection between applied ecotoxicological science and regulatory needs will facilitate the improved assessment of dioxin-like compounds in sediment and biota. Consequently, this will enable their application in sediment management programs, which is one of the main goals of the dioRAMA project.
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| 4. |
- Engwall, Magnus, 1965-, et al.
(author)
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Polycyclic aromatic hydrocarbons (PAHs) reduce hepatic beta-oxidation of fatty acids in chick embryos
- 2013
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In: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 20:3, s. 1881-1888
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Journal article (peer-reviewed)abstract
- Polycyclic aromatic hydrocarbons (PAHs) are widespread fused-ring contaminants formed during incomplete combustion of almost all kind of organic materials from both natural and anthropogenic sources. Some PAHs have been shown to be carcinogenic to humans, and a wide range of PAHs are found in wildlife all around the globe including avian species. The purpose of this project was to assess the effects of a standard mixture of 16 PAHs (United States Environmental Protection Agency) on the hepatic fatty acid beta-oxidation in chicken embryos (Gallus gallus domesticus) exposed in ovo. The hepatic beta-oxidation was measured using a tritium release assay with [9,10-H-3]-palmitic acid (16:0) as substrate. Treated groups were divided into groups of 0.05, 0.1, 0.3, 0.5, and 0.8 mg PAHs/kg egg weight. The hepatic beta-oxidation was reduced after exposure in ovo to the 16 PAHs mixture compared to control. The mechanisms causing reduced fatty acid oxidation in the present study are unclear, however may be due to deficient membrane structure, the functionality of enzymes controlling the rate of fatty acid entering into the mitochondria, or complex pathways connected to endocrine disruption. To the best of our knowledge, this is the first time a PAH-caused reduction of hepatic beta-oxidation of fatty acids in avian embryos has been observed. The implication of this finding on risk assessment of PAH exposure in avian wildlife remains to be determined.
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| 5. |
- Gustavsson, L., et al.
(author)
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Treatment of sludge containing nitro-aromatic compounds in reed-bed mesocosms : Water, BOD, carbon and nutrient removal
- 2012
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In: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 32:1, s. 104-109
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Journal article (peer-reviewed)abstract
- Since the mid-1970s, Sweden has been depositing 1 million ton d.w sludge/year, produced at waste water treatment plants. Due to recent legislation this practice is no longer a viable method of waste management. It is necessary to improve existing and develop new sludge management techniques and one promising alternative is the dewatering and treatment of sludge in constructed wetlands. The aim of this study was to follow reduction of organic carbon, BOD and nutrients in an industrial sludge containing nitro-aromatic compounds passing through constructed small-scale wetlands, and to investigate any toxic effect such as growth inhibition of the common reed Phragmites australis. The result showed high reduction of all tested parameters in all the outgoing water samples, which shows that constructed wetlands are suitable for carbon and nutrient removal. The results also showed that P. australis is tolerant to xenobiotics and did not appear to be affected by the toxic compounds in the sludge. The sludge residual on the top of the beds contained low levels of organic carbon and is considered non-organic and could therefore be landfilled. Using this type of secondary treatment method, the amount of sludge could be reduced by 50-70%, mainly by dewatering and biodegradation of organic compounds.
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| 6. |
- Keiter, Su, et al.
(author)
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Long-term effects of a binary mixture of perfluorooctane sulfonate (PFOS) and bisphenol A (BPA) in zebrafish (Danio rerio)
- 2012
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In: Aquatic Toxicology. - : Elsevier. - 0166-445X .- 1879-1514. ; 118-119, s. 116-129
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Journal article (peer-reviewed)abstract
- Previous in vitro studies have reported the potential of perfluorooctane sulfonate (PFOS) to increase the toxicity of other compounds. Given the complex nature of mixtures of environmental pollutants in aquatic systems together with the persistent and bioaccumulative properties of PFOS, this study aimed at evaluating the long-term effects and toxicity-increasing behavior of PFOS in vivo using the zebrafish (Danio rerio). Fish were maintained in flow-through conditions and exposed to single and binary mixtures of PFOS and the endocrine disruptor bisphenol A (BPA) at nominal concentrations of 0.6, 100 and 300 mu g/L and 10, 200 and 400 mu g/L, respectively. F1 and F2 generations were evaluated from 0 to 180 days post-fertilization (dpf) and F3 generation was evaluated from 0 to 14 dpf. Survival was documented in all generations, whereas growth, fecundity, fertilization rate, histological alterations (in liver, thyroid and gonads) and vitellogenin (Vtg) induction in males were evaluated for Fl and F2 generations. Data for growth were collected at 30, 90 and 180 dpf and data for histological evaluations and Vtg induction were analyzed at 90 and 180 dpf. No significant effects on survival were seen in the Fl generation in any treatment following 180 d exposure: however, in the F2 generation, 300 mu g/L PFOS both alone and in combination with BPA (10, 200 and 400 mu g/L) induced 100% mortality within 14 dpf. PFOS (0.6 and 300 mu g/L) did not increase the Vtg-inducing potential of BPA (10, 200 and 400 mu g/L) in a binary mixture. In contrast, binary mixtures with 300 mu g/L PFOS suppressed the Vtg levels in Fl males at 90 dpf when compared to single BPA exposures. Whereas the lowest tested PFOS concentration (0.6 mu g/L) showed an estrogenic potential in terms of significant Vtg induction, Vtg levels were generally found to decrease with increasing PFOS-exposure in both Fl and F2 generations. In Fl generation, BPA-exposure was found to increase Vtg levels in a concentration-dependent manner. Histological analyses of Fl and F2 fish revealed hepatocellular vacuolization, predominantly in males, following PFOS-exposure both alone and in combination with BPA. Hepatotoxicity by PFOS might explain the suppressed Vtg response seen in PFOS-exposed Fl and F2 males. PFOS-exposed fish also showed granulomas, mainly in the liver. Given previous reports of the immunosuppressive potential of PFOS, the granulomas could be a consequence of a PFOS-induced reduction of the immune response potential. In conclusion, the hypothesis that the presence of PFOS increases the endocrine potential of BPA could not be confirmed in zebrafish. Adverse effects on liver structure and survival were only seen at concentrations well above ecologically relevant concentrations; however, the decline in survival rates following PFOS-exposure seen over generations again documents the importance of long-term studies for the investigation of persistent environmental pollutants.
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| 7. |
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| 8. |
- Larsson, Maria, 1975-, et al.
(author)
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AhR-mediated activities of polycyclic aromatic compound (PAC) mixtures are predictable by the concept of concentration addition
- 2014
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In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 73, s. 94-103
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Journal article (peer-reviewed)abstract
- Risk assessments of polycyclic aromatic hydrocarbons (PAHs) are complicated because these compounds exist in the environment as complex mixtures of hundreds of individual PAHs and other related polycyclic aromatic compounds (PACs). In this study, the hypothesis that concentration addition (CA) can be used to predict the aryl hydrocarbon receptor (AhR)-mediated activity of PACs in mixtures containing various combinations of PACs was tested. AhR-mediated activities of 18 mixtures composed of two to 23 PACs, which included PAHs, azaarenes and oxygenated PAHs, were examined by the use of the AhR-based H4IIE-luc bioassay. Since greater AhR-mediated activities have been observed in soils contaminated by PAHs, investigations were done to test whether soil extract matrix or the presence of non-effect PACs might affect responses of the H4IIE-luc bioassay. Our results showed that AhR-mediated activities of mixtures of PACs could be predicted by the use of concentration addition. Additive activities of PACs in multi component mixtures along with the insignificant effect of the soil matrix support the use of concentration addition in mass balance calculations and AhR-based bioassays in risk assessment of environmental samples. However, independent action (IA) could not be used to predict the activity of mixtures of PACs.
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| 9. |
- Larsson, Maria, et al.
(author)
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Chemical and bioanalytical characterisation of PAHs in risk assessment of remediated PAH-contaminated soils
- 2013
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In: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 20:12, s. 8511-8520
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Journal article (peer-reviewed)abstract
- Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in soil at former industrial areas; and in Sweden, some of the most contaminated sites are being remediated. Generic guideline values for soil use after so-called successful remediation actions of PAH-contaminated soil are based on the 16 EPA priority pollutants, which only constitute a small part of the complex cocktail of toxicants in many contaminated soils. The aim of the study was to elucidate if the actual toxicological risks of soil samples from successful remediation projects could be reflected by chemical determination of these PAHs. We compared chemical analysis (GC-MS) and bioassay analysis (H4IIE-luc) of a number of remediated PAH-contaminated soils. The H4IIE-luc bioassay is an aryl hydrocarbon (Ah) receptor-based assay that detects compounds that activate the Ah receptor, one important mechanism for PAH toxicity. Comparison of the results showed that the bioassay-determined toxicity in the remediated soil samples could only be explained to a minor extent by the concentrations of the 16 priority PAHs. The current risk assessment method for PAH-contaminated soil in use in Sweden along with other countries, based on chemical analysis of selected PAHs, is missing toxicologically relevant PAHs and other similar substances. It is therefore reasonable to include bioassays in risk assessment and in the classification of remediated PAH-contaminated soils. This could minimise environmental and human health risks and enable greater safety in subsequent reuse of remediated soils.
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| 10. |
- Larsson, Maria, 1975-, et al.
(author)
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Time-dependent relative potency factors for polycyclic aromatic hydrocarbons and their derivatives in the H4IIE-luc bioassay
- 2014
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In: Environmental Toxicology and Chemistry. - Hoboken : Wiley-Blackwell. - 0730-7268 .- 1552-8618. ; 33:4, s. 943-953
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Journal article (peer-reviewed)abstract
- The H4IIE-luc transactivation bioassay for aryl hydrocarbon receptor (AhR) agonists was used to investigate the relative potency factors (REPs) of 22 individual polycyclic aromatic hydrocarbons (PAHs) and their oxygenated-, methylated-, and N-containing derivatives (azaarenes), which are often present in PAH-contaminated soils. Naphthacene and dibenz[ah]acridine exhibited greater AhR-mediated potency, whereas lesser molecular-weight azaarenes were less potent AhR agonists. Six oxygenated PAHs had calculable REPs, but their potencies were less than their parent PAHs. Unlike the parent, unsubstituted PAHs, oxidation of methylated PAHs seemed to increase the AhR-mediated potency of the compounds, with 2-methylanthracene-9,10-dione being almost 2 times more potent than 2-methylanthracene. Both bioassay and gas chromatography-mass spectrometry analysis were used to examine the exposure time-dependent effects on the REPs at 24 h, 48 h, and 72 h of exposure in the H4IIE-luc transactivation bioassay. Changes in concentrations of 5 compounds including the model reference 2,3,7,8-tetrachlorodibenzo-p-dioxin in the cell culture wells were measured, and the amounts in the cell medium, in the cells, and adsorbed to the wells was determined and the influence on the REPs was studied. Declining REP values with increased duration of exposure were shown for all compounds, which we concluded were a consequence of the metabolism of PAHs and PAH derivatives in H4IIe-luc cells. The present study provides new knowledge regarding the degradation and distribution of compounds in the wells during exposure. Environ Toxicol Chem 2014;33:943-953. (c) 2014 SETAC
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