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  • 1.
    Buitrago, B. Huerta
    et al.
    Mälardalen University, Västerås, Sweden.
    Munoz, P. Ferrer
    Mälardalen University, Västerås, Sweden.
    Ribe, V.
    Mälardalen University, Västerås, Sweden.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Wojciechowska, E.
    Gdansk University of Technology, Gdansk, Poland.
    Waara, S.
    Mälardalen University, Västerås, Sweden.
    Hazard assessment of sediments from a wetland system for treatment of landfill leachate using bioassays2013In: Ecotoxicology and Environmental Safety, ISSN 0147-6513, E-ISSN 1090-2414, Vol. 97, p. 255-262Article in journal (Refereed)
    Abstract [en]

    Four bioassays were used in this study for the hazard assessment of sediments from sediment traps and several ponds in a treatment wetland for landfill leachate at Atleverket, Sweden. In the 6-day solid phase microbiotest with the sediment-dwelling crustacean Heterocypris incongruens both acute and chronic effects were observed with a gradual decrease and loss of toxicity with treatment in the wetland system. Some samples showed a low toxicity in porewater and only one sample was weakly toxic in the whole sediment test when assessed with Aliivibrio fischeri (Vibro fischeri). No genotoxicity was detected in the umu test. The toxicity response in the H4IIE- luc test evaluating the presence of dioxin-like compounds was considerably higher in the samples from the sediment traps. The hazard of the sediment therefore appears to be highest in the sediment traps and pond 1 with the methods employed. The result indicates that the wetland system has a design supporting the concentration and sequestration of toxic substances in the first part of the wetland. Based upon the results we suggest that hazard assessment of sediments from other treatment wetlands for landfill leachate should be conducted. (c) 2013 Elsevier Inc. All rights reserved.

  • 2.
    Engwall, Magnus
    et al.
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Bioanalys av organiska föroreningars biotillgänglighet: tillämpning i sanerade massor2009Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Polycykliska aromatiska kolväten (PAHer) är relativt vanliga i förorenadeområden, särskilt på gamla gasverktomter, bensinstationer och tidigare impregneringsanläggningar.På grund av deras toxicitet så är sanering av PAH-förorenadeområden av hög prioritet. För att minska riskerna med PAH-förorenade jordar,både före och efter sanering, är det viktigt att åstadkomma en heltäckande riskbedömningoch säker klassning av dessa jordmassor. De generella riktvärden förPAH-förorenad mark som används idag är i regel baserade på kemisk analys av 16standard PAHer (PAH16), trots att det ofta förekommer 100-tals PAHer och PAHmetaboliteri jordarna.I detta projekt har vi genom att jämföra kemisk och biologisk analys (H4IIEluc)av ett flertal sanerade PAH-förorenade jordprover studerat om toxicitetenverkligen minskar i proportion till minskningen av PAHer i jordarna. H4IIE-luc ären mekanismspecifik bioanalys som detekterar alla ämnen som aktiverar Ahreceptorn,en av de två viktigaste mekanismerna bakom PAHers toxicitet. Jämförelsenav resultaten visade att den totala toxiciteten i de sanerade jordprovernainte gick att förklara med kemisk analys av PAH16 och att man därmed med dagensanalysmetodik riskerar att missa toxikologiskt relevanta PAHer och andra liknandeämnen. Vidare kemiska identifieringsstudier samt bioanalytiska studier krävs föratt ta reda på om dessa okända ämnen utgör en risk för människa eller miljö.Våra resultat visar på svagheten med kemisk analys av ett mindre antal ämnensom grundval för klassning av renade massor. Det är därför är rimligt att inkluderamekanismspecifika tester i riskbedömning och vid klassning av renade PAHförorenadejordar. Dels för att minimera riskerna som dessa jordar kan utgöra förmänniskor och miljö, dels för att man med en större säkerhet och i större utsträckningskall kunna återanvända sanerade jordmassor.

  • 3.
    Engwall, Magnus
    et al.
    Örebro University, School of Science and Technology.
    Venizelos, Nikolaos
    Örebro University, School of Health and Medical Sciences.
    Westman, Ola
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Nordén, Marcus
    Örebro University, School of Science and Technology.
    Hollert, Henner
    Rheinisch-Westfälische Technische Hochschule (RWTH), Aachen, Germany.
    Johansson, Jessica
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Polycyclic aromatic hydrocarbons (PAHs) reduce hepatic beta-oxidation of fatty acids in chick embryos2013In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, no 3, p. 1881-1888Article in journal (Refereed)
    Abstract [en]

    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.

  • 4.
    Hafner, Christoph
    et al.
    Hydrotox GmbH, Freiburg, Germany.
    Gartiser, Stefan
    Hydrotox GmbH, Freiburg, Germany.
    Garcia-Kaeufer, Manuel
    Hydrotox GmbH, Freiburg, Germany; Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Schiwy, Sabrina
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Hercher, Christoph
    Hydrotox GmbH, Freiburg, Germany.
    Meyer, Wiebke
    Institute of Geology and Palaeontology – Applied Geology, University of Münster, Münster, Germany.
    Achten, Christine
    Institute of Geology and Palaeontology – Applied Geology, University of Münster, Münster, Germany.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Keiter, Steffen
    Örebro University, School of Science and Technology. Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Hollert, Henner
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Investigations on sediment toxicity of German rivers applying a standardized bioassay battery2015In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 22, no 21, p. 16358-16370Article in journal (Refereed)
    Abstract [en]

    River sediments may contain a huge variety of environmental contaminants and play a key role in the ecological status of aquatic ecosystems. Contaminants adsorbed to sediments and suspended solids may contribute directly or after remobilization to an adverse ecological and chemical status of surface water. In this subproject of the joint research project DanTox, acetonic Soxhlet extracts from three German river sediments from the River Rhine (Altrip and Ehrenbreitstein with moderate contamination) and River Elbe (Veringkanal Hamburg heavily contaminated) were prepared and redissolved in dimethyl sulfoxide (DMSO). These extracts were analyzed with a standard bioassay battery with organisms from different trophic levels (bacteria, algae, Daphnia, fish) as well as in the Ames test and the umuC test for bacterial mutagenicity and genotoxicity according to the respective OECD and ISO guidelines. In total, 0.01 % (standard) up to 0.25 % (only fish embryo test) of the DMSO sediment extract was dosed to the test systems resulting in maximum sediment equivalent concentrations (SEQ) of 2 up to 50 g l(-1). The sediment of Veringkanal near Hamburg harbor was significantly more toxic in most tests compared to the sediment extracts from Altrip and Ehrenbreitstein from the River Rhine. The most toxic effect found for Veringkanal was in the algae test with an ErC50 (72 h) of 0.00226 g l(-1) SEQ. Ehrenbreitstein and Altrip samples were about factor 1,000 less toxic. In the Daphnia, Lemna, and acute fish toxicity tests, no toxicity at all was found at 2 g l(-1) SEQ. corresponding to 0.01 % DMSO. Only when increasing the DMSO concentration the fish embryo test showed a 22-fold higher toxicity for Veringkanal than for Ehrenbreitstein and Altrip samples, while the toxicity difference was less evident for the Daphnia test due to the overlaying solvent toxicity above 0.05 % dimethyl sulfoxide (DMSO). The higher toxicities observed with the Veringkanal sample are supported by the PAH and PCB concentrations analyzed in the sediments. The sediment extracts of Altrip andVeringkanal were mutagenic in the Ames tester strain TA98 with metabolic activation (S9mix). The findings allow a better ecotoxicological characterization of the sediments extensively analyzed in all subprojects of the DanTox project (e. g., Garcia-Kaeufer et al. Environ Sci Pollut Res. doi: 10.1007/s11356-014-3894-4, 2014; Schiwy et al. Environ Sci Pollut Res. doi: 10.1007/s11356-014-31850, 2014; Hollert and Keiter 2015). In the absence of agreed limit values for sediment extracts in standard tests, further data with unpolluted reference sediments are required for a quantitative risk assessment of the investigated polluted sediments.

  • 5.
    Kärrman, Anna
    et al.
    Örebro University, School of Science and Technology.
    Bjurlid, Filip
    Örebro University, School of Science and Technology.
    Hagberg, Jessika
    Örebro University, School of Science and Technology. School of Science and Technology, Örebro University, Örebro, Sweden.
    Ricklund, Niklas
    School of Science and Technology, Örebro University, Örebro, Sweden.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Stubleski, Jordan
    Örebro University, School of Science and Technology.
    Hollert, Henner
    Aachen University, Achen, Germany.
    Study of environmental and human health impacts of firefighting agents: A technical report2016Report (Other academic)
  • 6.
    Lam, Monika M.
    et al.
    Örebro University, School of Science and Technology.
    Bülow, Rebecca
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Giesy, John P.
    University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Methylated PACs are more potent than their parent compounds: a study on AhR-mediated activity, degradability and mixture interactions in the H4IIE-luc assayManuscript (preprint) (Other academic)
  • 7.
    Lam, Monika M.
    et al.
    Örebro University, School of Science and Technology.
    Bülow, Rebecca
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Giesy, John P.
    Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Canada.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Methylated PACs Are More Potent than Their Parent Compounds: A Study on AhR-mediated Activity, Degradability and Mixture Interactions in the H4IIE-luc Assay2018In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 37, no 5, p. 1409-1419Article in journal (Refereed)
    Abstract [en]

    Twenty-six polycyclic aromatic compounds (PACs; including native polycyclic aromatic hydrocarbons [PAHs], hydroxylated PAHs, alkylated and oxygenated PAHs, and [alkylated] heterocyclic compounds) were investigated for their aryl hydrocarbon receptor (AhR)-mediated potencies in the H4IIE-luc bioassay. Potential degradabilities of PACs were investigated by use of various durations of exposure (24, 48, or 72 h), and various mixtures of PACs including PAHs, alkylated and oxygenated PAHs, and heterocyclic compounds were tested for their joint AhR-mediated potency. Additive behaviors of PACs in mixtures were studied by comparing observed mixture potencies with mixture potencies predicted by use of the concentration addition model. Methylated derivatives were more potent than their parent compounds in the H4IIE-luc assay. A time-dependent decrease in relative potency was observed for all AhR-active compounds, which may be indicative of in vitro biotransformation. Monomethylated compounds seemed to be more rapidly transformed than analogous unsubstituted compounds. In addition, the results showed that the predictive power of the concentration addition model increased with the number of compounds, suggesting additivity in multicomponent mixtures. Due to the greater potency of methylated derivatives and their ubiquitous occurrence, there is a need for further research on the toxicity and mixture behavior of these environmentally and toxicologically relevant compounds.

  • 8.
    Lam, Monika M.
    et al.
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Denison, Michael S
    Department of Environmental Toxicology, University of California, Davis CA, USA.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Methylated polycyclic aromatic hydrocarbons and/or their metabolites are important contributors to the overall estrogenic activity of polycyclic aromatic hydrocarbon-contaminated soils2018In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 37, no 2, p. 385-397Article in journal (Refereed)
    Abstract [en]

    In the present study 42 polycyclic aromatic compounds (PACs) were investigated for their estrogenic potential using the VM7Luc4E2 transactivation assay. Relative potencies were determined for mass-balance analysis. In addition, compounds were tested in combination with the estrogen receptor (ER) antagonist vertical bar C vertical bar 182,780 (vertical bar C vertical bar) and the aryl hydrocarbon receptor antagonist/CYP1A1 inhibitor a-naphthoflavone. Luciferase induction and CYP1A1-dependent ethoxyresorufin-O-deethylase (EROD) activity were measured to assess whether the estrogenic activity was elicited by the compound itself and/or by its metabolites. Relative potencies ranged between 10(-7) and 10(-4). The ability of ICI to decrease luciferase activity stimulated by all compounds indicated that the induction responses were ER-dependent. The aryl hydrocarbon receptor antagonist/CYP1A1 inhibitor a-naphthoflavone decreased luciferase induction and EROD activity by several compounds, including the methylated chrysenes, suggesting that metabolites of these chemicals contributed to ER activation. Several PACs, such as acridine and its derivatives, appear to directly activate the ER. Furthermore, extracts of soils from industrial areas were examined using this bioassay, and estrogenic activity was detected in all soil samples. Mass-balance analysis using a combination of relative potencies and chemical analysis of the samples suggested that polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs, such as 1-and 3-methylchrysene, are important contributors to the overall estrogenic activity. However, these results revealed that a considerable proportion of the estrogenic activity in the soil remained unexplained, indicating the presence of other significant estrogenic compounds.

  • 9.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Chemical and bioanalytical characterisation of PAH-contaminated soils: identification, availability and mixture toxicity of AhR agonists2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Contaminated soils are a worldwide problem. Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in soil at former industrial areas, especially at old gasworks sites, gas stations and former wood impregnation facilities. Risk assessments of PAHs in contaminated soils are usually based on chemical analysis of a small number of individual PAHs, which only constitute a small part of the complex cocktail of hundreds of PAHs and other related polycyclic aromatic compounds (PACs) in the soils. Generally, the mixture composition of PAH-contaminated soils is rarely known and the mechanisms of toxicity and interactions between the pollutants are far from fully understood.

    The main objective of this thesis was to characterize remediated PAHcontaminated soils by use of a chemical and bioanalytical approach. Bioassay specific relative potency (REP) values for 38 PAHs and related PACs were developed in the sensitive H4IIE-luc bioassay and used in massbalance analysis of remediated PAH contaminated soils, to assess the contribution of chemically quantified compounds to the overall aryl hydrocarbon receptor (AhR)-mediated activity observed in the H4IIE-luc bioassay. Mixtures studies showed additive AhR-mediated effects of PACs, including PAHs, oxy PAHs, methylated PAHs and azaarenes, in the bioassay, which supports the use of REP values in risk assessment. The results from the chemical and bioassay analysis showed that PAH-contaminated soils contained a large fraction of AhR activating compounds whose effect could not be explained by chemical analysis of the 16 priority PAHs. Further chemical identification and biological studies are necessary to determine whether these unknown substances pose a risk to human health or the environment. Results presented in this thesis are an important step in the development of AhR-based bioassay analysis and risk assessment of complex PAH-contaminated samples.

    List of papers
    1. Exposure time-dependent effects on the relative potencies and additivity of PAHs in the Ah receptor-based H4IIE-luc bioassay
    Open this publication in new window or tab >>Exposure time-dependent effects on the relative potencies and additivity of PAHs in the Ah receptor-based H4IIE-luc bioassay
    2012 (English)In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 31, no 5, p. 1149-1157Article in journal (Refereed) Published
    Abstract [en]

    In the present study, relative potency factors (REPs) of 16 individual polycyclic aromatic hydrocarbons (PAHs) were investigated using the H4IIE-luc bioassay. Exposure time-dependent effects on the REPs were examined using 24, 48, and 72?h of exposure. Seven different mixtures of PAHs were tested for additivity at an exposure time of 24?h. Three of the PAH mixtures were also studied at 48 and 72?h of exposure. The mixture toxicities were predicted using the REP concept and the concentration addition (CA) model. Relative potency factor values investigated in the present study were similar to those reported in earlier studies. Declining REPs with an increasing exposure time were shown for all PAHs, indicating that this bioassay approach could be developed to assess the persistency of aryl hydrocarbon receptor (AhR) agonistic PAHs and in the risk assessment of complex PAH mixtures. The results from the mixture studies indicated that additive interactions of PAHs are time dependent. Generally, 48- and 72-h exposures resulted in biological effects that were similar to the CA and REP model predictions, while these models tended to underestimate the effect, to some extent, in the 24-h exposure, at least for the mixtures containing two to four PAHs. Thus, it cannot be ruled out that in the 24-h exposures, the tested PAH mixtures had slight synergistic effects. Further research is needed to identify and test additional AhR activating PAHs and investigate whether the effects in the H4IIE-luc bioassay are additive for more complex samples containing both PAHs and other AhR-activating contaminants. Also, the observed superinduction of luciferase by PAH-mixes warrants studies of whether this also can occur for relevant AhR-mediated endpoints in vivo. 

    Place, publisher, year, edition, pages
    Wiley-Blackwell, 2012
    Keywords
    PAHs, AhR agonists, Relative potencies, Mixture toxicity, Concentration-addition
    National Category
    Chemical Sciences Biological Sciences
    Research subject
    Biology; Chemistry
    Identifiers
    urn:nbn:se:oru:diva-22823 (URN)10.1002/etc.1776 (DOI)000302909800032 ()22328298 (PubMedID)2-s2.0-84859877788 (Scopus ID)
    Available from: 2012-05-14 Created: 2012-05-14 Last updated: 2017-12-07Bibliographically approved
    2. Chemical and bioanalytical characterisation of PAHs in risk assessment of remediated PAH-contaminated soils
    Open this publication in new window or tab >>Chemical and bioanalytical characterisation of PAHs in risk assessment of remediated PAH-contaminated soils
    Show others...
    2013 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, no 12, p. 8511-8520Article in journal (Refereed) Published
    Abstract [en]

    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.

    National Category
    Natural Sciences
    Research subject
    Biology; Environmental Chemistry; Enviromental Science
    Identifiers
    urn:nbn:se:oru:diva-29084 (URN)10.1007/s11356-013-1787-6 (DOI)000327498600022 ()
    Funder
    Knowledge FoundationSwedish Environmental Protection Agency
    Available from: 2013-05-21 Created: 2013-05-21 Last updated: 2017-12-06Bibliographically approved
    3. Time-dependent relative potency factors (REPS) for polycyclic aromatic hydrocarbons and their derivatives in the h4iie-luc
    Open this publication in new window or tab >>Time-dependent relative potency factors (REPS) for polycyclic aromatic hydrocarbons and their derivatives in the h4iie-luc
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The H4IIE-luc transactivation bioassay for aryl hydrocarbon receptor (AhR) agonists was used to investigate 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 AhRmediated potency, whereas lesser-molecular azaarenes were less potent AhR agonists. Six oxy-PAHs had calculable Relative potencies (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 methylanthracene-9,10-dione being almost two times more potent than methylanthracene. Both bioassay and gas chromatography–mass spectrometry (GC/MS) analysis were used to examine the exposure time dependent effects on the REPs at 24, 48 and 72 h of exposure in the H4IIE-luc transactivation bioassay. Changes in concentrations of five compounds including the model reference 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the cell culture wells were measured, and the amounts in the cell medium, the cells and adsorbed to the wells determined and the influence on the REPs was studied. Declining REP values with increased duration of exposure were shown for all compounds and proved to be 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.

    Keywords
    Polycyclic aromatic compounds, monitoring, soils, organic contaminants, in vitro toxicology, toxic equivalents
    National Category
    Chemical Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-32665 (URN)
    Available from: 2013-12-06 Created: 2013-12-06 Last updated: 2017-10-17Bibliographically approved
    4. Concentration-addition in risk assessment: prediction of potential AhR-mediated activity in multiple polycyclic aromatic compound (PAC) mixtures
    Open this publication in new window or tab >>Concentration-addition in risk assessment: prediction of potential AhR-mediated activity in multiple polycyclic aromatic compound (PAC) mixtures
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    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 potency of PACs in mixtures containing various combinations of PACs. Effects of 18 mixtures composed of two to 23 PACs, which included PAHs, azaarenes and oxygenated PAHs, were examined by use of the AhR based H4IIE-luc bioassay. Since greater AhR-mediated activities have been observed in soils contaminated by PAH, investigations were done to test whether soil extract matrix or presence of noneffect PACs might affect responses of the H4IIE-luc bioassay. AhR-mediated activity of the mixture of PACs could be predicted by use of concentration addition. Additive behavior of PACs in multi component mixtures supported the hypothesis that use of concentration addition could be used in risk assessment of PAC- mixtures. However, independent action (IA) could not be used to predict the activity of mixtures of PACs. 

    Keywords
    Polycyclic aromatic hydrocarbons, Independent action, concentration addition, H4IIE-luc
    National Category
    Chemical Sciences
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:oru:diva-32667 (URN)
    Available from: 2013-12-06 Created: 2013-12-06 Last updated: 2017-10-17Bibliographically approved
  • 10.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Giesy, John P.
    Department of Veterinary Biomedical Sciences and Toxicological Center, University of Saskatchewan, Saskatoon, Canada; Department of Zoology and Center for Integrative Toxicology, Michigan State University, East Lansing MI, USA; Department of Biology and Chemistry, State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China; School of Biological Sciences, University of Hong Kong, Hong Kong, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    AhR-mediated activities of polycyclic aromatic compound (PAC) mixtures are predictable by the concept of concentration addition2014In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 73, p. 94-103Article in journal (Refereed)
    Abstract [en]

    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.

  • 11.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Giesy, John P.
    Department of Veterinary Biomedical Sciences & Toxicological Center, University of Saskatchewan, Saskatoon, Canada; Department of Zoology, and Center for Integrative Toxicology, Michigan State University, USA Department of Biology & Chemistry and State Key Laboratory in Marine Pollution, City University of Hong Kong, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, China.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Concentration-addition in risk assessment: prediction of potential AhR-mediated activity in multiple polycyclic aromatic compound (PAC) mixturesManuscript (preprint) (Other academic)
    Abstract [en]

    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 potency of PACs in mixtures containing various combinations of PACs. Effects of 18 mixtures composed of two to 23 PACs, which included PAHs, azaarenes and oxygenated PAHs, were examined by use of the AhR based H4IIE-luc bioassay. Since greater AhR-mediated activities have been observed in soils contaminated by PAH, investigations were done to test whether soil extract matrix or presence of noneffect PACs might affect responses of the H4IIE-luc bioassay. AhR-mediated activity of the mixture of PACs could be predicted by use of concentration addition. Additive behavior of PACs in multi component mixtures supported the hypothesis that use of concentration addition could be used in risk assessment of PAC- mixtures. However, independent action (IA) could not be used to predict the activity of mixtures of PACs. 

  • 12.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Hagberg, Jessika
    Örebro University, School of Science and Technology.
    Giesy, John P.
    Dept Vet Biomed Sci, Univ Saskatchewan, Saskatoon SK, Canada; Toxicol Ctr, Univ Saskatchewan, Saskatoon SK, Canada; Dept Zool, Michigan State Univ, E Lansing, USA; Ctr Integrat Toxicol, Michigan State Univ, E Lansing, USA; Dept Biol & Chem, City Univ Hong Kong, Kowloon, Peoples R China; State Key Lab Marine Pollut, City Univ Hong Kong, Kowloon, Peoples R China; Sch Biol Sci, Univ Hong Kong, Hong Kong, Peoples R China; Sch Environm, State Key Lab Pollut Control & Resource Reuse, Nanjing Univ, Nanjing, Peoples R China .
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Time-dependent relative potency factors for polycyclic aromatic hydrocarbons and their derivatives in the H4IIE-luc bioassay2014In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 33, no 4, p. 943-953Article in journal (Refereed)
    Abstract [en]

    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

  • 13.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Hagberg, Jessika
    Örebro University, School of Science and Technology.
    Giesy, John P
    Department of Biology & Chemistry and State Key Laboratory in Marine Pollution & School of Biological Sciences, University of Hong Kong, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University,China.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Time-dependent relative potency factors (REPS) for polycyclic aromatic hydrocarbons and their derivatives in the h4iie-lucManuscript (preprint) (Other academic)
    Abstract [en]

    The H4IIE-luc transactivation bioassay for aryl hydrocarbon receptor (AhR) agonists was used to investigate 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 AhRmediated potency, whereas lesser-molecular azaarenes were less potent AhR agonists. Six oxy-PAHs had calculable Relative potencies (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 methylanthracene-9,10-dione being almost two times more potent than methylanthracene. Both bioassay and gas chromatography–mass spectrometry (GC/MS) analysis were used to examine the exposure time dependent effects on the REPs at 24, 48 and 72 h of exposure in the H4IIE-luc transactivation bioassay. Changes in concentrations of five compounds including the model reference 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the cell culture wells were measured, and the amounts in the cell medium, the cells and adsorbed to the wells determined and the influence on the REPs was studied. Declining REP values with increased duration of exposure were shown for all compounds and proved to be 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.

  • 14.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Hagberg, Jessika
    Örebro University, School of Science and Technology.
    Rotander, Anna
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Chemical and bioanalytical characterisation of PAHs in risk assessment of remediated PAH-contaminated soilsManuscript (preprint) (Other academic)
    Abstract [en]

    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 PAHcontaminated 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. 

  • 15.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Hagberg, Jessika
    Örebro University, School of Science and Technology.
    Rotander, Anna
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Chemical and bioanalytical characterisation of PAHs in risk assessment of remediated PAH-contaminated soils2013In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, no 12, p. 8511-8520Article in journal (Refereed)
    Abstract [en]

    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.

  • 16.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Lam, Monika M.
    Örebro University, School of Science and Technology.
    van Hees, Patrick
    Örebro University, School of Science and Technology. Eurofins Environment Testing Sweden AB, Lidköping, Sweden.
    Giesy, John P.
    University of Saskatchewan, Saskatoon, Canada.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Occurrence and leachability of polycyclic aromatic compounds in contaminated soils: Chemical and bioanalytical characterization2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 622-623, p. 1476-1484Article in journal (Refereed)
    Abstract [en]

    An important concern regarding sites contaminated with polycyclic aromatic compounds (PACs) is the risk of groundwater contamination by release of the compounds from soils. The goal of this study was to investigate the occurrence and leachability of 77 PACs including polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic compounds (NSO-PACs) among total aryl hydrocarbon receptor (AhR) agonists in soils from historical contaminated sites. A novel approach combining chemical and bioanalytical methods in combination with characterization of leachability by use of a column leaching test was used. Similar profiles of relative concentrations of PACs were observed in all soils, with parent PAHs accounting for 71 to 90% of total concentrations in soils. Contribution of oxy-PAHs, alkyl-PAHs and N-PACs ranged from 2 to 9%, 3 to 9% and 1 to 14%, respectively. Although the contributions of groups of PACs were small, some compounds were found in similar or greater concentrations than parent PAHs. Leachable fractions of 77 PACs from soils were small and ranged from 0.002 to 0.54%. Polar PACs were shown to be more leachable than parent PAHs. The contribution of analyzed PACS to overall AhR-mediated activities in soils and leachates suggests presence of other AhR agonists in soils, and a potential risk. Only a small fraction of AhR agonists was available in soils, indicating an overestimation of the risk if only total initial concentrations in soils would be considered in risk assessment. The results of the study strongly support that focus on 16US EPA PAHs may result in inadequate assessment of risk and hazard of PACs in complex environmental samples.

  • 17.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Orbe, Dan
    MTM Research Centre, Sweden.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Ah receptor activating capacity of polycyclic aromatic hydrocarbon derivatives2012In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 211, no Supplement, p. s127-, article id P16-18Article in journal (Refereed)
  • 18.
    Larsson, Maria
    et al.
    Örebro University, School of Science and Technology.
    Orbe, Dan
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Exposure time-dependent effects on the relative potencies and additivity of PAHs in the Ah receptor-based H4IIE-luc bioassay2012In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 31, no 5, p. 1149-1157Article in journal (Refereed)
    Abstract [en]

    In the present study, relative potency factors (REPs) of 16 individual polycyclic aromatic hydrocarbons (PAHs) were investigated using the H4IIE-luc bioassay. Exposure time-dependent effects on the REPs were examined using 24, 48, and 72?h of exposure. Seven different mixtures of PAHs were tested for additivity at an exposure time of 24?h. Three of the PAH mixtures were also studied at 48 and 72?h of exposure. The mixture toxicities were predicted using the REP concept and the concentration addition (CA) model. Relative potency factor values investigated in the present study were similar to those reported in earlier studies. Declining REPs with an increasing exposure time were shown for all PAHs, indicating that this bioassay approach could be developed to assess the persistency of aryl hydrocarbon receptor (AhR) agonistic PAHs and in the risk assessment of complex PAH mixtures. The results from the mixture studies indicated that additive interactions of PAHs are time dependent. Generally, 48- and 72-h exposures resulted in biological effects that were similar to the CA and REP model predictions, while these models tended to underestimate the effect, to some extent, in the 24-h exposure, at least for the mixtures containing two to four PAHs. Thus, it cannot be ruled out that in the 24-h exposures, the tested PAH mixtures had slight synergistic effects. Further research is needed to identify and test additional AhR activating PAHs and investigate whether the effects in the H4IIE-luc bioassay are additive for more complex samples containing both PAHs and other AhR-activating contaminants. Also, the observed superinduction of luciferase by PAH-mixes warrants studies of whether this also can occur for relevant AhR-mediated endpoints in vivo. 

  • 19.
    Meyer-Alert, Henriette
    et al.
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Ladermann, Kim
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Schiwy, Sabrina
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Hollert, Henner
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt – Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Keiter, Steffen H.
    Örebro University, School of Science and Technology.
    A temporal high-resolution investigation of the Ah-receptor pathway during early development of zebrafish (Danio rerio)2018In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 204, p. 117-129Article in journal (Refereed)
    Abstract [en]

    In order to contribute to a comprehensive understanding of the regulating mechanisms of the aryl-hydrocarbon-receptor (AHR) in zebrafish embryos, we aimed to elucidate the interaction of proteins taking part in this signaling pathway during early development of the zebrafish (Danio rerio) after chemical exposure. We managed to illustrate initial transcription processes of the implemented proteins after exposure to two environmentally relevant chemicals: polychlorinated biphenyl 126 (PCB126) and β-Naphthoflavone (BNF). Using qPCR, we quantified mRNA every 4 h until 118 h post fertilization and found the expression of biotransformation enzymes (cyp1 family) and the repressor of the AHR (ahr-r) to be dependent on the duration of chemical exposure and the biodegradability of the compounds. PCB126 induced persistently increased amounts of transcripts as it is not metabolized, whereas activation by BNF was limited to the initial period of exposure. We did not find a clear relation between the amount of transcripts and activity of the induced CYP-proteins, so posttranscriptional mechanisms are likely to regulate biotransformation of BNF. With regard to zebrafish embryos and their application in risk assessment of hazardous chemicals, our examination of the AHR pathway especially supports the relevance of the time point or period of exposure that is used for bioanalytical investigations and consideration of chemical properties determining biodegradability.

  • 20.
    Meyer-Alert, Henriette
    et al.
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Hollert, Henner
    Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
    Keiter, Steffen
    Örebro University, School of Science and Technology.
    Benzo[a]pyrene and 2,3-benzofuran induce divergent temporal patterns of AhR-regulated responses in zebrafish embryos (Danio rerio)2019In: Ecotoxicology and Environmental Safety, ISSN 0147-6513, E-ISSN 1090-2414, Vol. 183, article id UNSP 109505Article in journal (Refereed)
    Abstract [en]

    Biotests like the fish embryo toxicity test have become increasingly popular in risk assessment and evaluation of chemicals found in the environment. The large range of possible endpoints is a big advantage when researching on the mode of action of a certain substance. Here, we utilized the frequently used model organism zebrafish (Danio rerio) to examine regulative mechanisms in the pathway of the aryl-hydrocarbon receptor (AHR) in early development. We exposed embryos to representatives of two chemical classes known to elicit dioxin-like activity: benzo[a]pyrene for polycyclic aromatic hydrocarbons (PAHs) and 2,3-benzofuran for polar O-substituted heterocycles as a member of heterocyclic compounds in general (N-, S-, O-heterocycles; NSO-hets). We measured gene transcription of the induced P450 cytochromes (cyp1), their formation of protein and biotransformation activity throughout the whole embryonic development until 5 days after fertilization. The results show a very specific time course of transcription depending on the chemical properties (e.g. halogenation, planarity, Kow), the physical decay and the biodegradability of the tested compound. However, although this temporal pattern was not precisely transferable onto the protein level, significant regulation in enzymatic activity over time could be detected. We conclude, that a careful choice of time and end point as well as consideration of the chemical properties of a substance are fairly important when planning, conducting and especially evaluating biotests.

  • 21.
    Schönlau, Christine
    et al.
    Örebro University, School of Science and Technology.
    Holmes, Breanne
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Kärrman, Anna
    Örebro University, School of Science and Technology.
    Screening for bioactivities in three types of microplastics deployed in Swedish aquatic environments using a battery of reporter gene assaysManuscript (preprint) (Other academic)
  • 22.
    Schönlau, Christine
    et al.
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Dubocq, Florian
    Örebro University, School of Science and Technology.
    Rotander, Anna
    Örebro University, School of Science and Technology.
    Van der Zande, Rene
    Coral Reef Ecosystems Lab and Global Change Institute, The University of Queensland, St. Lucia QLD, Australia.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Kärrman, Anna
    Örebro University, School of Science and Technology.
    Effect-Directed Analysis of Ah Receptor-Mediated Potencies in Microplastics Deployed in a Remote Tropical Marine Environment2019In: Frontiers in Environmental Science, E-ISSN 2296-665X, Vol. 7, article id 120Article in journal (Refereed)
    Abstract [en]

    To facilitate the study of potential harmful compounds sorbed to microplastics, an effect-directed analysis using the DR CALUX® assay as screening tool for Aryl hydrocarbon receptor (AhR)-active compounds in extracts of marine deployed microplastics and chemical analysis of hydrophobic organic compounds (HOCs) was conducted. Pellets of three plastic polymers [low-density polyethylene (LDPE), high-density polyethylene (HDPE) and high-impact polystyrene (HIPS)] were deployed at Heron Island in the Great Barrier Reef, Australia, for up to 8 months. Detected AhR-mediated potencies (bio-TEQs) of extracted plastic pellets ranged from 15 to 100 pg/g. Contributions of target HOCs to the overall bioactivities were negligible. To identify the major contributors, remaining plastic pellets were used for fractionation with a gas chromatography (GC) fractionation platform featuring parallel mass spectrometric (MS) detection. The bioassay analysis showed two bioactive fractions of each polymer with bio-TEQs ranging from 5.7 to 14 pg/g. High resolution MS was used in order to identify bioactive compounds in the fractions. No AhR agonists could be identified in fractions of HDPE or LDPE. Via a multivariate statistical approach the polystyrene (PS) trimer 1e- Phenyl-4e-(1- phenylethyl)-tetralin was identified in fractions of HIPS and in fractions of the blank polymer of HIPS.

  • 23.
    Schönlau, Christine
    et al.
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Lam, Monika M.
    School of Science and Technology, Örebro University, Örebro, Sweden.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Giesy, John P.
    Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
    Rochman, Chelsea
    University of California, Davis, CA, USA; Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.
    Kärrman, Anna
    Örebro University, School of Science and Technology.
    Aryl hydrocarbon receptor-mediated potencies in field-deployed plastics vary by type of polymer2019In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, no 9, p. 9097-9088Article in journal (Refereed)
    Abstract [en]

    Plastic is able to sorb environmental pollutants from ambient water and might act as a vector for these pollutants to marine organisms. The potential toxicological effects of plastic-sorbed pollutants in marine organisms have not been thoroughly assessed. In this study, organic extracts from four types of plastic deployed for 9 or 12 months in San Diego Bay, California, were examined for their potential to activate the aryl hydrocarbon receptor (AhR) pathway by use of the H4IIE-luc assay. Polycyclic aromatic hydrocarbons (PAH), including the 16 priority PAHs, were quantified. The AhR-mediated potency in the deployed plastic samples, calculated as bio-TEQ values, ranged from 2.7 pg/g in polyethylene terephthalate (PET) to 277 pg/g in low-density polyethylene (LDPE). Concentrations of the sum of 24 PAHs in the deployed samples ranged from 4.6 to 1068 ng/g. By use of relative potency factors (REP), a potency balance between the biological effect (bio-TEQs) and the targeted PAHs (chem-TEQs) was calculated to 24-170%. The study reports, for the first time, in vitro AhR-mediated potencies for different deployed plastics, of which LDPE elicited the greatest concentration of bio-TEQs followed by polypropylene (PP), PET, and polyvinylchloride (PVC).

  • 24.
    Westman, Ola
    et al.
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Hollert, Henner
    2RWTH Aachen University, Inst. For Environmental Research, Department of Ecosystem Analysis, Aachen, Germany.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Comparative study and characterization of mutagenicity and AhR-agonistic potency of contaminated soil, remediated soil, urban city soil and rural soilManuscript (preprint) (Other academic)
    Abstract [en]

    Current risk assessment of PAH-contaminated soils is usually based on chemical analysis of a small number of PAHs. The use of effect-based methods for risk assessment would yield results covering more of the effect of all the chemicals in the soil. To put such effect based data into context we tested a relative approach in which effects of contaminated soil were compared to clean rural and urban soils. This concept of relative risk assessment was tested by studying the mutagenic and AhR-agonistic potency of contaminated soil and urban soil compared to farm soil from selected ecological farms. A set of 21 soil samples was collected: 11 PAH-contaminated samples (collected in collaboration with three Swedish remediation companies), 5 urban samples (collected in Swedish cities) and 5 soil samples from ecological farms. The urban and rural samples were collected at the surface (0-10 cm deep), the contaminated samples were collected from piles during remediation (100-200 cm deep). To evaluate the toxicants in the soil sample, lipophilic sample extracts were tested in two different assays; (i) the Ames Fluctuation Assay (AFA) mutant strains TA98 and TA100 of Salmonella typhimurium with and without a metabolic activation system (rat-liver homogenate S9) to determine the mutagenic potential of the soil samples and (ii) the cell mechanism-specific H4IIE-luc assay to determine the Ahreceptor (AhR) activating potency of the soil extracts. The results showed clear mutagenicity, both direct and indirect, in one of the PAH-contaminated samples and three other PAH samples also demonstrated some mutagenic activity. The extracts from urban city soil showed mutagenicity in three of the 5 samples, while none of the ecological farm samples had mutagenic extracts. The bio-TEQ values were very high for all remediated samples and elevated in one urban sample. Bio-TEQ values were low in the ecological farm extracts. These findings demonstrate that the present investigation scheme using two different bioassays to determine the mutagenic potential and the Ah receptor activating potency of soil extracts is a suitable method for testing toxic properties of soil extracts. The concept of relative risk assessment using background samples from rural and urban areas and effect based testing shows promise for further development.

  • 25.
    Westman, Ola
    et al.
    Örebro University, School of Science and Technology. Structor Miljöteknik AB, Örebro, Sweden.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Venizelos, Nikolaos
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Hollert, Henner
    Institute for Environmental Research, Department of Ecosystem Analysis, RWTH Aachen University, Aachen, Germany.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    An oxygenated metabolite of benzo[a]pyrene increases hepatic beta-oxidation of fatty acids in chick embryos2014In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 21, no 9, p. 6243-6251Article in journal (Refereed)
    Abstract [en]

    Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogens to humans and ecotoxicological effects have been shown in several studies. However, PAHs can also be oxidized into more water soluble-oxygenated metabolites (Oxy-PAHs). The first purpose of the present project was to (1) assess the effects of a mixture containing three parent PAHs: anthracene, benz[a]anthracene, and benzo[a]pyrene versus a mixture of their oxygenated metabolites, namely: anthracene-9,10-dione, benz[a]anthracene-7,12-dione, and 9,10-dihydrobenzo[a]pyrene-7-(8H)-one on the hepatic fatty acid beta-oxidation in chicken embryos (Gallus gallus domesticus) exposed in ovo. The second and also main purpose of the project was to (2) assess the effects of the parent PAHs versus their oxy-PAHs analogues when injected individually, followed by (3) additional testing of the individual oxy-PAHs. The hepatic beta-oxidation was measured using a tritium release assay with [9,10-H-3]-palmitic acid (16:0) as substrate. The result from the first part (1) showed reduced hepatic beta-oxidation after exposure in ovo to a mixture of three PAHs, however, increased after exposure to the mixture of three oxy-PAHs compared to control. The result from the second part (2) and also the follow-up experiment (3) showed that 9,10-dihydrobenzo[a]pyrene-7-(8H)-one was the causative oxy-PAH. The implication of this finding on the risk assessment of PAH metabolite exposure in avian wildlife remains to be determined. To the best of our knowledge, no similar studies have been reported.

  • 26.
    Westman, Ola
    et al.
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Venizelos, Nikolaos
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Hollert, Henner
    3RWTH Aachen University, Inst. For Environmental Research, Department of Ecosystem Analysis, Aachen, Germany.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    An oxygenated metabolite of benzo[a]pyrene increases hepatic β-oxidation of fatty acids in chick embryosManuscript (preprint) (Other academic)
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    Örebro University, School of Science and Technology.
    Nordén, Marcus
    Örebro University, School of Science and Technology.
    Larsson, Maria
    Örebro University, School of Science and Technology.
    Venizelos, Nikolaos
    Örebro University, School of Science and Technology.
    Hollert, Henner
    RWTH Aachen University, Aachen, Germany.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    Reduced beta-oxidation in avian following exposure of polycyclic aromatic hydrocarbons2012In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 211, no Supplement, p. s86-s87Article in journal (Refereed)
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