Change search
Refine search result
1234 1 - 50 of 152
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Al-Anati, Lauy
    et al.
    Viluksela, Matti
    Strid, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Toxicology Sciences Research Center (Swetox), Sweden.
    Andersson, Patrik L.
    Stenius, Ulla
    Högberg, Johan
    Hydroxyl metabolite of PCB 180 induces DNA damage signaling and enhances the DNA damaging effect of benzo[a]pyrene2015In: Chemico-Biological Interactions, ISSN 0009-2797, E-ISSN 1872-7786, Vol. 239, p. 164-173Article in journal (Refereed)
    Abstract [en]

    Non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) and their hydroxyl metabolites (OH-PCBs) are ubiquitous environmental contaminants in human tissues and blood. The toxicological impact of these metabolites is poorly understood. In this study rats were exposed to ultrapure PCB180 (10-1000 mg/kg bw) for 28 days and induction of genotoxic stress in liver was investigated. DNA damage signaling proteins (pChk1Ser317 and gamma H2AXSer319) were increased dose dependently in female rats. This increase was paralleled by increasing levels of the metabolite 3'-OH-PCB180. pChk1 was the most sensitive marker. In in vitro studies HepG2 cells were exposed to 1 mu M of PCB180 and 3'-OH-PCB180 or the positive control benzo[a]pyrene (BaP, 5 mu M). 3'-OH-PCB180, but not PCB180, induced CYP1A1 mRNA and gamma H2AX. CYP1A1 mRNA induction was seen at 1 h, and gamma H2AX at 3 h. The anti-oxidant N-Acetyl-L-Cysteine (NAC) completely prevented, and 17 beta-estradiol amplified the gamma H2AX induction by 3'-OH-PCB180. As 3'-OH-PCB180 induced CYP1A1, a major BaP-metabolizing and activating enzyme, interactions between 3'-OH-PCB180 and BaP was also studied. The metabolite amplified the DNA damage signaling response to BaP. In conclusion, metabolism of PCB180 to its hydroxyl metabolite and the subsequent induction of CYP1A1 seem important for DNA damage induced by PCB180 in vivo. Amplification of the response with estradiol may explain why DNA damage was only seen in female rats.

  • 2. Alexander, Jan
    et al.
    Benford, Diane
    Boobis, Alan
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Scientific Opinion on Hexabromocyclododecanes (HBCDDs) in Food2011In: EFSA Journal, ISSN 1831-4732, Vol. 9, no 7, p. 2296-Article in journal (Other academic)
    Abstract [en]

    EFSA was asked by the European Commission to deliver a scientific opinion on hexabromocyclododecanes (HBCDDs) in food. HBCDDs are additive flame retardants primarily used in expanded and extruded polystyrene applied as construction and packing materials, and in textiles. Technical HBCDD predominantly consists of three stereoisomers (α-, β- and γ-HBCDD). Also δ- and ε-HBCDD may be present but at very low concentrations. HBCDDs are present in the environment and likewise in biota and in food and feed. Data from the analysis of HBCDDs in 1,914 food samples were provided to EFSA by seven European countries, covering the period from 2000 to 2010. The Panel on Contaminants in the Food Chain (CONTAM Panel) selected α-, β- and γ-HBCDD to be of primary interest. Since all toxicity studies were carried out with technical HBCDD, a risk assessment of individual stereoisomers was not possible. Main targets were the liver, thyroid hormone homeostasis and the reproductive, nervous and immune systems. HBCDDs are not genotoxic. The CONTAM Panel identified neurodevelopmental effects on behaviour as the critical endpoint, and derived a benchmark dose lower confidence limit for a benchmark response of 10 % (BMDL10) of 0.79 mg/kg body weight. Due to the limitations and uncertainties in the current data base, the CONTAM Panel concluded that it was inappropriate to use this BMDL to establish a health based guidance value, and instead used a margin of exposure (MOE) approach for the health risk assessment of HBCDDs. Since elimination characteristics of HBCDDs in animals and humans differ, the Panel used the body burden as starting point for the MOE approach. The CONTAM Panel concluded that current dietary exposure to HBCDDs in the European Union does not raise a health concern. Also additional exposure, particularly of young children, to HBCDDs from house dust is unlikely to raise a health concern

  • 3. Alexander, Jan
    et al.
    Benford, Diane
    Boobis, Alan
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Scientific Opinion on Polybrominated Diphenyl Ethers (PBDEs) in Food2011In: EFSA Journal, ISSN 1831-4732, Vol. 9, no 5, p. 2156-Article in journal (Other academic)
  • 4. Alexander, Jan
    et al.
    Benford, Diane
    Boobis, Alan
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Scientific Opinion on Tetrabromobisphenol A (TBBPA) and its derivatives in food: EFSA Panel on Contaminants in the Food Chain (CONTAM)2011In: EFSA Journal, ISSN 1831-4732, Vol. 9, no 12, p. 2477-Article in journal (Refereed)
    Abstract [en]

    EFSA was asked by the European Commission to deliver a scientific opinion on tetrabromobisphenol A (TBBPA) and its derivatives in food. TBBPA and its derivatives are widely used as flame retardants. TBBPA is primarily used as reactive flame retardant covalently bound to epoxy and polycarbonate resins. TBBPA derivatives are used as either reactive or additive intermediates in polymer manufacture. Data from the analysis of TBBPA in 344 food samples were submitted to EFSA by two European countries (Norway and Spain), covering the period from 2007 to 2010. All samples were in the food group “Fish and other seafood”, and all analytical results were reported as less than the limit of quantification (LOQ) (about 1 ng/g wet weight). Toxicological studies with TBBPA have been carried out using different experimental designs with single or repeated administration during gestation, postnatally or in adulthood. The main target is thyroid hormone homeostasis. TBBPA is not genotoxic. There are no indications that TBBPA might be carcinogenic. The Panel on Contaminants in the Food Chain (CONTAM Panel) identified a lower confidence limit for a benchmark response of 10 % (BMDL10) of 16 mg/kg b.w. reported for changes in thyroid hormones as the critical reference point. Due to the limitations and uncertainties in the database, the CONTAM Panel concluded that it was inappropriate to use this BMDL to establish a health based guidance value, and therefore used a margin of exposure (MOE) approach for the health risk assessment of TBBPA. In view of the large MOEs, the CONTAM Panel concluded that current dietary exposure to TBBPA in the European Union does not raise a health concern. Also exposure of infants via human milk does not raise a health concern. Additional exposure, particularly of young children, to TBBPA from house dust is unlikely to raise a health concern.

  • 5. Alm, Henrik
    et al.
    Scholz, Birger
    Kultima, Kim
    Nilsson, Anna
    Andren, Per E.
    Savitski, Mikhail M.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Stigson, Michael
    Fex-Svenningsen, Asa
    Dencker, Lennart
    In Vitro Neurotoxicity of PBDE-99: Immediate and Concentration-Dependent Effects on Protein Expression in Cerebral Cortex Cells2010In: Journal of Proteome Research, ISSN 1535-3893, E-ISSN 1535-3907, Vol. 9, no 3, p. 1226-1235Article in journal (Refereed)
    Abstract [en]

    Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in various consumer products. Pre- and postnatal exposure to congeners of PBDEs disrupts normal brain development in rodents. Two-dimensional difference gel electrophoresis (2D-DIGE) was used to analyze concentration-dependent differences in protein expression in cultured cortical cells isolated from rat fetuses (GD 21) after 24 h exposure to PBDE-99 (3, 10, or 30 mu M). Changes on a post-translational level were studied using a 1 h exposure to 30 mu M PBDE-99. The effects of 24 h exposure to 3 and 30 mu M PBDE-99 on mRNA levels were measured using oligonucleotide microarrays. A total of 62, 46, and 443 proteins were differentially expressed compared to controls after 24 h of exposure to 3, 10, and 30 mu M PDBE-99, respectively. Of these, 48, 43, and 238 proteins were successfully identified, respectively. We propose that the biological effects of low-concentration PBDE-99 exposure are fundamentally different than effects of high-concentration exposure. Low-dose PBDE-99 exposure induced marked effects on cytoskeletal proteins, which was not correlated to cytotoxicity or major morphological effects, suggesting that other more regulatory aspects of cytoskeletal functions may be affected. Interestingly, 0.3 and 3 mu M, but not 10 or 30 mu M increased the expression of phosphorylated (active) Gap43, perhaps reflecting effects on neurite extension processes.

  • 6.
    Asp, V
    et al.
    Department of Environmental Toxicology, Uppsala University.
    Cantillana, T
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Brandt, I
    Department of Environmental Toxicology, Uppsala University.
    Chiral effects in adrenocorticolytic action of o,p'-DDD (mitotane) in human adrenal cells2010In: Xenobiotica, ISSN 0049-8254, E-ISSN 1366-5928, Vol. 40, no 3, p. 177-183Article in journal (Refereed)
    Abstract [en]

    1. Adrenocortical carcinoma (ACC) is a rare malignant disease with poor prognosis. The main pharmacological choice, o,p'-DDD (mitotane), produces severe adverse effects. 2. Since o,p'-DDD is a chiral molecule and stereoisomers frequently possess different pharmacokinetic and/or pharmacodynamic properties, we isolated the two o,p'-DDD enantiomers, (R)-(+)-o,p'-DDD and (S)-(-)-o,p'-DDD, and determined their absolute structures. 3. The effects of each enantiomer on cell viability and on cortisol and dehydroepiandrosterone (DHEA) secretion in the human adrenocortical cell line H295R were assessed. We also assayed the o, p'-DDD racemate and the m,p'- and p,p'-isomers. 4. The results show small but statistically significant differences in activity of the o, p'-DDD enantiomers for all parameters tested. The three DDD isomers were equally potent in decreasing cell viability, but p, p'- DDD affected hormone secretion slightly less than the o,p'- and m,p'-isomers. 5. The small chiral differences in direct effects on target cells alone do not warrant single enantiomer administration, but might reach importance in conjunction with possible stereochemical effects on pharmacokinetic processes in vivo.

  • 7.
    Asplund, L
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Löfstrand, K
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Malmvärn, A
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Nylund, K
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Eriksson, U
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    OH-PBDEs and MeO-PBDEs in swedish marine and fresh water environment- an overview2010In: Organohalogen Compounds, 2010Conference paper (Other academic)
  • 8.
    Athanasiadou, Maria
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Marsh, Göran
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Asplund, Lillemor
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Gas chromatography and mass spectrometry of methoxylated polybrominated diphenyl ethers (MeO-PBDEs).2006In: J Mass Spectrom, ISSN 1076-5174, Vol. 41, no 6, p. 790-801Article in journal (Other academic)
  • 9.
    Bastos, Patricia Moreira
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Johan
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Green, Nicholas
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    A standardized method for assessment of oxidative transformations of brominated phenols in water.2008In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 70, no 7, p. 1196-202Article in journal (Refereed)
  • 10.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Alla kemister behöver miljökemin2010In: Kemivärlden Biotech med Kemisk Tidskrift, Vol. 10, p. 59-Article in journal (Refereed)
  • 11.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    BFR Exposure: Air, particles and food matters2007In: 4th International Workshop on Brominated Flame Retardants: BFR 2007 Amsterdam, 2007Conference paper (Other (popular science, discussion, etc.))
  • 12.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Foreword2012In: Hormone-Disruptive Chemical Contaminants in Food / [ed] I. Pongratz and L. Vikström Bergander, London: Royal Society of Chemistry, 2012Chapter in book (Other academic)
  • 13.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Hur förgiftad är vår miljö?2010In: Miljöforskning; Formas tidning för ett hållbart samhälle, Vol. 4, p. 18-21Article in journal (Refereed)
  • 14.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Perspective on recent developments of persistent and bioaccumulative BFRs2008In: BFR 2008: 10th Annual workshop on brominated flame retardants, 2008, p. 9-Conference paper (Other (popular science, discussion, etc.))
  • 15.
    Bergman, Åke
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish toxicology sciences research center, Sweden; Karolinska Institutet, Sweden; Tongji University, China.
    Bignert, AndersQiu, YanlingStockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.Yin, GeStockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Chemical Pollution - Challenges in the Yangtze River Delta, China: A 2017 Sino-Swedish Research Report2017Collection (editor) (Other academic)
    Abstract [en]

    Over time China became the globally most important manufacturer of chemicals and inherited the pollution problems with production and use of chemicals. The Yangtze River Delta is very much a central area for the chemical production and for manufacturing of a variety of chemical products, materials and goods. A science based cooperation between researchers from Tongji University, Stockholm University and the Swedish Museum of Natural History started to develop in the first decade of the present century. The cooperation was aimed to improve the understanding of chemical pollutants and their influence on wildlife and humans in the Yangtze River Delta area, to generate novel data and establish advanced chemical monitoring programs.

    Chemical Pollution — Challenges in the Yangtze River Delta is the first scientific report of the Chemstrres project, "Swedish-Chinese chemical pollution stress and risks research program in the Yangtze River Delta region". The project has been funded by the Swedish Research Council. This book covers the essentials of the natural, social, economic, and chemical environments of the Yangtze River Delta, as well as an up-to-date, introduction of the research activities and highlights within Chemstrres. The book is aimed to attract readers from all sectors of society; vivid graphics and diagrams can be found throughout the text. Both Chemstrres project and this book are expected to bring scientists and decision makers closer together, to enable science based management for improved human health and environmental prosperity. 

  • 16.
    Bergman, Åke
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Lindgren, Torsten
    Smedje, Greta
    Jakobsson, Kristina
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Athanasiadou, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Meyer, Edgar
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    PBDEs and non-PBDEs in aircraft cabin and cockpit air and dust2010In: Organohalogen Compounds, 2010Conference paper (Other academic)
  • 17.
    Bergman, Åke
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Rydén, Andreas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Law, Robin J.
    de Boer, Jacob
    Covaci, Adrian
    Alaee, Mehran
    Birnbaum, Linda
    Petreas, Myrto
    Rose, Martin
    Sakai, Shinichi
    Van den Eede, Nele
    van der Veen, Ike
    A novel abbreviation standard for organobromine, organochlorine and organophosphorus flame retardants and some characteristics of the chemicals2012In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 49, p. 57-82Article, review/survey (Refereed)
    Abstract [en]

    Ever since the interest in organic environmental contaminants first emerged 50 years ago, there has been a need to present discussion of such chemicals and their transformation products using simple abbreviations so as to avoid the repetitive use of long chemical names. As the number of chemicals of concern has increased, the number of abbreviations has also increased dramatically, sometimes resulting in the use of different abbreviations for the same chemical. In this article, we propose abbreviations for flame retardants (FRs) substituted with bromine or chlorine atoms or including a functional group containing phosphorus, i.e. BFRs, CFRs and PFRs, respectively. Due to the large number of halogenated and organophosphorus FRs, it has become increasingly important to develop a strategy for abbreviating the chemical names of FRs. In this paper, a two step procedure is proposed for deriving practical abbreviations (PRABs) for the chemicals discussed. In the first step, structural abbreviations (STABs) are developed using specific STAB criteria based on the FR structure. However, since several of the derived STABs are complicated and long, we propose instead the use of PRABs. These are, commonly, an extract of the most essential part of the STAB, while also considering abbreviations previously used in the literature. We indicate how these can be used to develop an abbreviation that can be generally accepted by scientists and other professionals involved in FR related work. Tables with PRABs and STABs for BFRs, CFRs and PERs are presented, including CAS (Chemical Abstract Service) numbers, notes of abbreviations that have been used previously, CA (Chemical Abstract) name, common names and trade names, as well as some fundamental physicochemical constants.

  • 18.
    Bergman, Åke
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    van den Berg, Martin
    Some bifocal views of risks of BFRs2007In: Organohalogen Compounds: Plenary Lecture, 2007, p. 7-9Conference paper (Refereed)
  • 19. Birnbaum, Linda S.
    et al.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Brominated and Chlorinated Flame Retardants: The San Antonio Statement2010In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 118, no 12, p. A516-A518Article in journal (Refereed)
    Abstract [en]

    The San Antonio Statement on Brominated and Chlorinated Flame Retardants addresses the growing concern in the scientific community about the persistent, bioaccumulative, and toxic properties of brominated and chlorinated organic flame retardants (BFRs and CFRs, respectively) and the exposure to humans and wildlife as a result of intensive use. Nearly 150 scientists from 22 countries have signed the statement since it was presented at the 30th International Symposium on Halogenated Persistent Organic Pollutants (Dioxin 2010), held 1217 September 2010 in San Antonio, Texas. The scientist signatories are experts on the health effects and environmental fate of BFRs and CFRs and environmental contaminants in general. The International Panel on Chemical Pollution (IPCP), an international network of scientists working on various aspects of chemical pollution, also has approved the statement.

  • 20. Björk, C
    et al.
    Nenonen, H
    Giwercman, Alexander
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Rylander, Lars
    Lundberg Giwercman, Yvonne
    The impact of CB-153 and p,p’-DDE on androgen receptor function2009In: Organohalogen Compounds, Vol. 71, Peking, 2009, p. 816-819Conference paper (Refereed)
  • 21. Björk, Christel
    et al.
    Nenonen, Hannah
    Giwercman, Aleksander
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Rylander, Lars
    Giwercman, Yvonne Lundberg
    Persistent organic pollutants have dose and CAG repeat length dependent effects on androgen receptor activity in vitro2011In: Reproductive Toxicology, ISSN 0890-6238, E-ISSN 1873-1708, Vol. 32, p. 293-297Article in journal (Refereed)
    Abstract [en]

    Recently, the effect of exposure to persistent organic pollutants (POPS) on sperm concentration was only seen in men with a short androgen receptor (AR) gene CAG repeat. In order to investigate whether these effects could be observed also in vitro, we tested the impact of 2,2’,4,4’,5,5’-hexachlorobiphenyl (CB-153) and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (4,4’-DDE) on 5 alpha-dihydrotestosterone activated ARs containing 16,22 and 28 CAG repeats, respectively. Single exposure to 4,4’-DDE had the most pronounced effect on the AR activity containing 16 CAG repeats, whereas 28 CAG was the most sensitive variant when a mixture of the two compounds was added. Thus, our in vitro results have confirmed the in vivo data indicating a CAG repeat length dependent effect of endocrine disrupters on the AR activity.

  • 22.
    Bogdanska, Jasna
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Borg, Daniel
    Sundström, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Bergström, Ulrika
    Halldin, Krister
    Abedi-Valugerdi, Manuchehr
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Nelson, Buck
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    DePierre, Joseph
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Nobel, Stefan
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Tissue distribution of (35)S-labelled perfluorooctane sulfonate in adult mice after oral exposure to a low environmentally relevant dose or a high experimental dose2011In: Toxicology, ISSN 0300-483X, E-ISSN 1879-3185, Vol. 284, no 1-3, p. 54-62Article in journal (Refereed)
    Abstract [en]

    The widespread environmental pollutant perfluorooctane sulfonate (PFOS), detected in most animal species including the general human population, exerts several effects on experimental animals, e.g., hepatotoxicity, immunotoxicity and developmental toxicity. However, detailed information on the tissue distribution of PFOS in mammals is scarce and, in particular, the lack of available information regarding environmentally relevant exposure levels limits our understanding of how mammals (including humans) may be affected. Accordingly, we characterized the tissue distribution of this compound in mice, an important experimental animal for studying PFOS toxicity. Following dietary exposure of adult male C57/BL6 mice for 1-5 days to an environmentally relevant (0.031 mg/kg/day) or a 750-fold higher experimentally relevant dose (23 mg/kg/day) of (35)S-PFOS, most of the radioactivity administered was recovered in liver, bone (bone marrow), blood, skin and muscle, with the highest levels detected in liver, lung, blood, kidney and bone (bone marrow). Following high daily dose exposure, PFOS exhibited a different distribution profile than with low daily dose exposure, which indicated a shift in distribution from the blood to the tissues with increasing dose. Both scintillation counting (with correction for the blood present in the tissues) and whole-body autoradiography revealed the presence of PFOS in all 19 tissues examined, with identification of thymus as a novel site for localization for PFOS and bone (bone marrow), skin and muscle as significant body compartments for PFOS. These findings demonstrate that PFOS leaves the bloodstream and enters most tissues in a dose-dependent manner.

  • 23.
    Bogdanska, Jasna
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Sundström, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bergström, Ulrika
    Borg, Daniel
    Abedi-Valugerdi, Manuchehr
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    DePierre, Joseph
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Nobel, Stefan
    Tissue distribution of S-35-labelled perfluorobutanesulfonic acid in adult mice following dietary exposure for 1-5 days2014In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 98, p. 28-36Article in journal (Refereed)
    Abstract [en]

    Perfluorobutanesulfonyl fluoride (PBSF) has been introduced as a replacement for its eight-carbon homolog perfluorooctanesulfonyl fluoride (POSF) in the manufacturing of fluorochemicals. Fluorochemicals derived from PBSF may give rise to perfluorobutanesulfonic acid (PFBS) as a terminal degradation product. Although basic mammalian toxicokinetic data exist for PFBS, information on its tissue distribution has only been reported in one study focused on rat liver. Therefore, here we characterized the tissue distribution of PFBS in mice in the same manner as we earlier examined its eight-carbon homolog perfluorooctanesulfonate (PFOS) to allow direct comparisons. Following dietary exposure of adult male C57/BL6 mice for 1,3 or 5 d to 16 mg S-35-PFBS kg(-1) d(-1), both scintillation counting and whole-body autoradiography (WBA) revealed the presence of PFBS in all of the 20 different tissues examined, demonstrating its ability to leave the bloodstream and enter tissues. After 5 d of treatment the highest levels were detected in liver, gastrointestinal tract, blood, kidney, cartilage, whole bone, lungs and thyroid gland. WBA revealed relatively high levels of PFBS in male genital organs as well, with the exception of the testis. The tissue levels increased from 1 to 3 d of exposure but appeared thereafter to level-off in most cases. The estimated major body compartments were whole bone, liver, blood, skin and muscle. This exposure to PFBS resulted in 5-40-fold lower tissue levels than did similar exposure to PFOS, as well as in a different pattern of tissue distribution, including lower levels in liver and lungs relative to blood.

  • 24.
    Bogdanska, Jasna
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Sundström, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bergström, Ulrika
    Institutionen för miljötoxikologi, Uppsala universitet.
    Borg, Daniel
    Institutet för miljömedicin, Karolinska institutet.
    Abedi-Valugerdi, Mauchehr
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Nelson, Buck
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    DePierre, Joseph
    Institutionen för biokemi och biofysik, Department of Biochemistry and Biophysics.
    Nobel, Stefan
    Department of molecular medicin and surgery, Karolinska institutet.
    Tissue distribution of 35S-labelled perfluorobutane sulfonic acid in adult mice following dietary exposure for 1-5 daysManuscript (preprint) (Other academic)
  • 25. Borg, D.
    et al.
    Bogdanska, J.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Sundström, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Nobel, S.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Håkansson, H.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    DePierre, J. W.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Halldin, K.
    Bergstrom, U.
    Tissue distribution of S-35-labelled perfluorooctane sulfonate (PFOS) in C57Bl/6 mice following late gestational exposure2010In: Reproductive Toxicology, ISSN 0890-6238, E-ISSN 1873-1708, Vol. 30, no 4, p. 558-565Article in journal (Refereed)
    Abstract [en]

    Exposure of rodents in utero to perfluorooctane sulfonate (PFOS) impairs perinatal development and survival Following intravenous or gavage exposure of C57Bl/6 mouse dams on gestational day (GD) 16 to S-35-PFOS (12 5 mg/kg) we determined the distribution in dams fetuses (GD18 and GD20) and pups (postnatal day 1 PND1) employing whole-body autoradiography and liquid scintillation counting In dams levels were highest in liver and lungs After placental transfer S-35-PFOS was present on GD18 at 2-3 times higher levels in lungs liver and kidneys than in maternal blood In PND1 pups levels in lungs were significantly higher than in GD18 fetuses A heterogeneous distribution of S-35-PFOS was observed in brains of fetuses and pups with levels higher than in maternal brain This first demonstration of substantial localization of PFOS to both perinatal and adult lungs is consistent with evidence describing the lung as a target for the toxicity of PFOS at these ages.

  • 26. Borg, Daniel
    et al.
    Bogdanska,, Jasna
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Sundström, Maria
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Nobel, Stefan
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Håkansson, Helen
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    DePierre, Joseph
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Halldin, Krister
    Bergström, Ulrika
    Perinatal tissue distribution of perfluorooctane sulphonate (PFOS) in mice2009In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 189, no SI, p. S147-S147Article in journal (Refereed)
  • 27.
    Cantillana, T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Lindström, V.
    Eriksson, L.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Brandt, I.
    Bergman, Å.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Interindividual differences in o,p '-DDD enantiomer kinetics examined in Göttingen minipigs2009In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Chemosphere, Vol. 76, no 2, p. 167-172Article in journal (Refereed)
  • 28.
    Cantillana, Tatiana
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Hermansson, Veronica
    Brandt, Ingvar
    Bergman, Åke
    Enantiomer fractions of o,p'-DDD in plasma and tissues from Göttingen minipigs2007In: Organohalogen Compounds: Chiral Compounds, 2007, p. 271-274Conference paper (Refereed)
  • 29.
    Cantillana, Tatiana
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Sundström, Maria
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Synthesis of 2-(4-chlorophenyl)-2-(4-chloro-3-thiophenol)-1,1-dichloroethene (3-SH-DDE) via Newman-Kwart rearrangement - A precursor for synthesis of radiolabeled and unlabeled alkylsulfonyl-DDEs2009In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, ISSN 0045-6535, Vol. 76, no 6, p. 805-810Article in journal (Refereed)
    Abstract [en]

    For the first time, a pathway for synthesis of 2-(4-chlorophenyl)-2-(4-chloro-3-thiophenol)-1,1-dichloroethene (3-SH-DDE), is presented. The compound is of particular interest as a precursor for synthesis of alkylsulfonyl-DDE containing different alkyl groups to discover structural activity relationships, and to promote synthesis of radiolabeled methylsulfonyl-DDE. 2-Chloro-5-methyl phenol was first methylated and further oxidized to the corresponding benzoic acid. The acid was reduced to the corresponding aldehyde (4-chloro-3-methoxy benzaldehyde) via 4-chloro-3-methoxy-benzene methanol. A lead/aluminium bimetal system was used to carry out the reductive addition of tetrachloromethane to 4-chloro-3-methoxy benzaldehyde to obtain 2,2,2-trichloro-1-(4-chloro-3-methoxyphenyl)ethanol,the desired starting material to synthesize the DDT-analogue (2-(4-chlorophenyl)-2-(4-chloro-3-methoxy-phenyl)-1,1,1-trichloroethane). Elimination of hydrochloric acid and removal of the methyl group led to the 3-OH-DDE. The Newman-Kwart rearrangement was applied to convert 3-OH-DDE to 3-SH-DDE via the dimethyl-carbarnothioate derivative. 3-SH-DDE is then used as a precursor for the radiolabel synthesis. The overall yield to acquire 3-SH-DDE after 11 steps was 3%. The step with the lowest yield was the DDT-analog synthesis with a yield of 30%. All other step had a yield of >50%. 3-SH-DDE was methylated with C-14-labeled iodomethane and oxidized by hydrogen peroxide to obtain 3-[C-14]MeSO2-DDE in an overall yield of 30%.

  • 30.
    Christiansson, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Johan
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Teclechiel, Daniel
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Identification and quantification of products formed via photolysis of decabromodiphenyl ether2009In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 16, no 3, p. 312-321Article in journal (Refereed)
    Abstract [en]

    BACKGROUND, AIM, AND SCOPE: Decabromodiphenyl ether (DecaBDE) is used as an additive flame retardant in polymers. It has become a ubiquitous environmental contaminant, particularly abundant in abiotic media, such as sediments, air, and dust, and also present in wildlife and in humans. The main DecaBDE constituent, perbrominated diphenyl ether (BDE-209), is susceptible to transformations as observed in experimental work. This work is aimed at identifying and assessing the relative amounts of products formed after UV irradiation of BDE-209. MATERIALS AND METHODS: BDE-209, dissolved in tetrahydrofuran (THF), methanol, or combinations of methanol/water, was exposed to UV light for 100 or 200 min. Samples were analyzed by gas chromatography/mass spectrometry (electron ionization) for polybrominated diphenyl ethers (PBDEs), dibenzofurans (PBDFs), methoxylated PBDEs, and phenolic PBDE products. RESULTS: The products formed were hexaBDEs to nonaBDEs, monoBDFs to pentaBDFs, and methoxylated tetraBDFs to pentaBDFs. The products found in the fraction containing halogenated phenols were assigned to be pentabromophenol, dihydroxytetrabromobenzene, dihydroxydibromodibenzofuran, dihydroxytribromodibenzofuran, and dihydroxytetrabromodibenzofuran. The PBDEs accounted for approximately 90% of the total amount of substances in each sample and the PBDFs for about 10%. DISCUSSION: BDE-209 is a source of PBDEs primarily present in OctaBDEs but also to some extent in PentaBDEs, both being commercial products now banned within the EU and in several states within the USA. It is notable that OH-PBDFs have not been identified or indicated in any of the photolysis studies performed to date. Formation of OH-PBDFs, however, may occur as pure radical reactions in the atmosphere. CONCLUSIONS: Photolysis of decaBDE yields a wide span of products, from nonaBDEs to hydroxylated bromobenzenes. It is evident that irradiation of decaBDE in water and methanol yields OH-PBDFs and MeO-PBDFs, respectively. BDE-202 (2,2',3,3',5,5',6,6'-octabromodiphenyl ether) is identified as a marker of BDE-209 photolysis. RECOMMENDATIONS AND PERSPECTIVES: BDE-209, the main constituent of DecaBDE, is primarily forming debrominated diphenyl ethers with higher persistence which are more bioaccumulative than the starting material when subjected to UV light. Hence, DecaBDE should be considered as a source of these PBDE congeners in the environment

  • 31.
    Christiansson, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Hovander, Lotta
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Jakobsson, Kristina
    Department of Occupational and Environmental Medicine, Lund University Hospital.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Polybrominated diphenyl ethers in aircraft cabins – a source of human exposure?2008In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 73, no 10, p. 1654-1660Article in journal (Refereed)
    Abstract [en]

    Commercial aircrafts need a high degree of fire protection for passenger safety. Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), may be used for this purpose. Because PBDEs readily absorb to dust particles, aircraft crew and passengers may receive significant PBDEs exposure via inhalation. The aims of this work were to assess whether PBDEs could be found in aircraft cabin dust and whether serum levels of PBDEs increased in passengers after long-distance flights. Hence nine subjects on intercontinental flights collected cabin dust samples, as well as donated blood samples before departure and after return to Sweden. Two subjects who were domestic frequent flyers were also investigated. The levels of PBDEs in dust and serum were determined by GC/MS in electron capture negative ionization (ECNI) mode. Authentic reference substances were used for identification and quantitation. PBDEs were found in all aircraft dust samples at high concentrations, higher than in common household dust. Congener patterns indicated that the technical products PentaBDE, OctaBDE and DecaBDE were used in the aircrafts. Serum concentrations in the travellers were similar to those observed in Swedish residents in general. Post-travel serum levels of BDE-28, BDE-99, BDE-100, BDE-153, and BDE-154 were significantly higher (p < 0.05) than concentrations prior to travel. The findings from this pilot study call for investigations of occupational exposures to PBDEs in cabin and cockpit crews.

  • 32.
    Dahlberg, Anna-Karin
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Lindberg Chen, Vivian
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Larsson, Kjell
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Toxicology Sciences Research Center (Swetox), Sweden.
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Hydroxylated and methoxylated polybrominated diphenyl ethers in long-tailed ducks (Clangula hyemalis) and their main food, Baltic blue mussels (Mytilus trossulus x Mytilus edulis).2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 144, p. 1475-1483Article in journal (Refereed)
    Abstract [en]

    Long-tailed ducks (Clangula hyemalis) that breed in northern Europe and western Siberia and commonly winter in the Baltic Sea, are threatened by a significant population decrease. The ducks are, by primarily feeding on Baltic blue mussels (Mytilus trossulus x Mytilus edulis) while wintering in the Baltic Sea, potentially subjected to high levels of toxic hydroxylated polybrominated diphenyl ethers (OH-PBDEs). To assess long-tailed ducks exposure to polybrominated phenols (PBPs), polybrominated anisoles (PBAs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methylated counterparts (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs), livers of ten long-tailed ducks wintering in the Baltic Sea were analysed. Pattern and levels of analytes in long-tailed ducks (liver) and blue mussels sampled in March and May at nine sites in the Baltic Sea were compared. The geometric mean concentration (ng/g l.w.) in livers of long-tailed ducks and Baltic blue mussels were: Sigma(2)PBPs: 0.57 and 48; Sigma 2PBAs: 0.83 and 11; Sigma 7OH-PBDEs: 6.1 and 45; Sigma 7MeO-PBDEs: 3.8 and 69; Sigma 7PBDEs: 8.0 and 7.2, respectively. Based on an estimated daily intake of 450 g fresh blue mussel meat, long-tailed ducks daily dietary intake of brominated substances while foraging in the Baltic Sea in March-May was estimated to; 390 ng Sigma(2)PBPs, 90 ng Sigma 2PBAs, 370 ng Sigma 7OH-PBDEs, 590 ng Sigma 7MeO-PBDEs and 59 ng Sigma 7PBDEs. The low levels of PBPs, PBAs, OH-PBDEs and MeO-PBDEs in the long-tailed duck livers compared to blue mussel, despite a continuous daily intake, suggest that these compounds are poorly retained in long-tailed ducks.

  • 33.
    Dahlberg, Anna-Karin
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Norrgran, Jessica
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hovander, Lotta
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Recovery discrepancies of OH-PBDEs and polybromophenols in human plasma and cat serum versus herring and long-tailed duck plasma2014In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 94, p. 97-103Article in journal (Refereed)
    Abstract [en]

    Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of polybrominated diphenyl ethers (PBDEs) and/or as natural products. The OH-PBDEs and polybromophenols have come into focus over the last decade due to their abundance in biota and their potential adverse health effects. The present recovery study aims to validate a commonly used method (published by Hovander et al. 2000) for OH-PBDE analysis in human plasma. Further, the authors intended to determine the method's applicability to serum/plasma matrices from other species than humans. The investigated matrices were human plasma, cat serum, herring- and long-tailed duck plasma. The recovery study included nine OH-PBDEs, four polybromophenols and three methoxylated PBDEs (MeO-PBDEs). Five replicates of each matrix were spiked with these compounds at two dose levels; a low dose (0.5 ng) and a high dose (5 ng) and were cleaned up according to the Hovander method. The recovery of OH-PBDEs and polybromophenols in human plasma and cat serum were high and reproducible at both dose levels whereas the recovery for herring and long-tailed duck plasma were low and insufficient with great variability amongst OH-PBDE congeners at both dose levels. Our data show that the method can be fully applied to matrices like human plasma and cat serum but not for herring and long-tailed duck plasma without further method development. Hence care needs to be taken when applying the method onto other blood matrices without validation since the present study have demonstrated that the recoveries may differ amongst OH-PBDE congeners and specie.

  • 34. DiGangi, Joseph
    et al.
    Blum, Arlene
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Lucas, Donald
    Mortimer, David
    Schecter, Arnold
    Scheringer, Martin
    Shaw, Susan
    Webster, Tomas F.
    San Antonio Statement on brominated and chlorinated flame retardants2010In: Environmental Health Perspectives, ISSN 0091-6765, Vol. 118, no 12, p. A516-A518Article in journal (Refereed)
  • 35. Dingemans, Milou M L
    et al.
    de Groot, Aart
    van Kleef, Regina G D M
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    van den Berg, Martin
    Vijverberg, Henk P M
    Westerink, Remco H S
    Hydroxylation increases the neurotoxic potential of BDE-47 to affect exocytosis and calcium homeostasis in PC12 cells.2008In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 116, no 5, p. 637-43Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Oxidative metabolism, resulting in the formation of hydroxylated polybrominated diphenyl ether (PBDE) metabolites, may enhance the neurotoxic potential of brominated flame retardants. OBJECTIVE: Our objective was to investigate the effects of a hydroxylated metabolite of 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47; 6-OH-BDE-47) on changes in the intracellular Ca2+ concentration ([Ca2+]i) and vesicular catecholamine release in PC12 cells. METHODS: We measured vesicular catecholamine release and [Ca2+]i using amperometry and imaging of the fluorescent Ca2+-sensitive dye Fura-2, respectively. RESULTS: Acute exposure of PC12 cells to 6-OH-BDE-47 (5 microM) induced vesicular catecholamine release. Catecholamine release coincided with a transient increase in [Ca2+]i, which was observed shortly after the onset of exposure to 6-OH-BDE-47 (120 microM). An additional late increase in [Ca2+]i was often observed at &gt; or =1 microM 6-OH-BDE-47. The initial transient increase was absent in cells exposed to the parent compound BDE-47, whereas the late increase was observed only at 20 microM. Using the mitochondrial uncoupler carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP) and thapsigargin to empty intracellular Ca2+ stores, we found that the initial increase originates from emptying of the endoplasmic reticulum and consequent influx of extracellular Ca2+, whereas the late increase originates primarily from mitochondria. CONCLUSION: The hydroxylated metabolite 6-OH-BDE-47 is more potent in disturbing Ca2+ homeostasis and neurotransmitter release than the parent compound BDE-47. The present findings indicate that bioactivation by oxidative metabolism adds considerably to the neurotoxic potential of PBDEs. Additionally, based on the observed mechanism of action, a cumulative neurotoxic effect of PBDEs and ortho-substituted polychlorinated biphenyls on [Ca2+]i cannot be ruled out.

  • 36. Dingemans, Milou M. L.
    et al.
    Heusinkveld, Harm J.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    van den Berg, Martin
    Westerink, Remco H. S.
    Bromination Pattern of Hydroxylated Metabolites of BDE-47 Affects Their Potency to Release Calcium from Intracellular Stores in PC12 Cells2010In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 118, no 4, p. 519-525Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Brominated flame retardants, including the widely used polybrominated diphenyl ethers (PBDEs), have been detected in humans, raising concern about possible neurotoxicity. Recent research demonstrated that the hydroxylated metabolite 6-OH-BDE-47 increases neurotransmitter release by releasing calcium ions (Ca2+) from intracellular stores at much lower concentrations than its environmentally relevant parent congener BDE-47. Recently, several other hydroxylated BDE-47 metabolites, besides 6-OH-BDE-47, have been detected in human serum and cord blood. OBJECTIVE AND METHODS: To investigate the neurotoxic potential of other environmentally relevant PBDEs and their metabolites, we examined and compared the acute effects of BDE-47, BDE-49, BDE-99, BDE-100, BDE-153, and several metabolites of BDE-47-6-OH-BDE-47 (and its methoxylated analog 6-MeO-BDE-47), 6'-OH-BDE-49, 5-OH-BDE-47, 3-OH-BDE-47, and 4'-OH-BDE-49 on intracellular Ca2+ concentration ([Ca2+](i)), measured using the Ca2+-responsive dye Fura-2 in neuroendocrine pheochromocytoma (PC12) cells. RESULTS: In contrast to the parent PBDEs and 6-MeO-BDE-47, all hydroxylated metabolites induced Ca2+ release from intracellular stores, although with different lowest observed effect concentrations (LOECs). The major intracellular Ca2+ sources were either endoplasmic reticulum (ER; 5-OH-BDE-47 and 6'-OH-BDE-49) or both ER and mitochondria (6-OH-BDE-47, 3-OH-BDE-47, and 4'-OH-BDE-49). When investigating fluctuations in [Ca2+](i), which is a more subtle end point, we observed lower LOECs for 6-OH-BDE-47 and 4'-OH-BDE-49, as well as for BDE-47. CONCLUSIONS: The present findings demonstrate that hydroxylated metabolites of BDE-47 cause disturbance of the [Ca2+](i). Importantly, shielding of the OH group on both sides with bromine atoms and/or the ether bond to the other phenyl ring lowers the potency of hydroxylated PBDE metabolites.

  • 37. Dingemans, Milou M L
    et al.
    Heusinkveld, Harm J
    de Groot, Aart
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    van den Berg, Martin
    Westerink, Remco H S
    Hexabromocyclododecane (HBCD) inhibits depolarization-induced increase in intracellular calcium levels and neurotransmitter release in PC12 cells.2009In: Toxicol Sci, ISSN 1096-0929, Vol. 107, no 2, p. 490-498Article in journal (Other academic)
    Abstract [en]

    Environmental levels of the brominated flame retardant (BFR) hexabromocyclododecane (HBCD) have been increasing. HBCD has been shown to cause adverse effects on learning and behavior in mice, as well as on dopamine uptake in rat synaptosomes and synaptic vesicles. For other BFRs, alterations in the intracellular Ca(2+) homeostasis have been observed. Therefore, the aim of this study was to investigate whether the technical HBCD mixture and individual stereoisomers affect the intracellular Ca(2+) concentration ([Ca(2+)](i)) in a neuroendocrine in vitro model (PC12 cells). [Ca(2+)](i) and vesicular catecholamine release were measured using respectively single-cell Fura-2 imaging and amperometry. Exposure of PC12 cells to the technical HBCD mixture or individual stereoisomers did neither affect basal [Ca(2+)](i), nor the frequency of basal neurotransmitter release. However, exposure to HBCD (0 - 20 muM) did cause a dose-dependent reduction of a subsequent depolarization-evoked increase in [Ca(2+)](i). This effect was apparent only when HBCD was applied at least 5 min before depolarization (maximum effect after 20 min exposure). The effects of alpha- and beta-HBCD were comparable to that of the technical mixture, whereas the inhibitory effect of gamma-HBCD was larger. Using specific blockers of L-, N- or P/Q-type voltage-gated Ca(2+) channels (VGCCs) it was shown that the inhibitory effect of HBCD is not VGCC-specific. Additionally, the number of cells showing depolarization-evoked neurotransmitter release was markedly reduced following HBCD exposure. Summarizing, HBCD inhibits depolarization-evoked [Ca(2+)](i) and neurotransmitter release. As increasing HBCD levels should be anticipated, these findings justify additional efforts to establish an adequate exposure, hazard and risk assessment.

  • 38. Dingemans, Milou M. L.
    et al.
    Heusinkveld, Harm J.
    de Groot, Aart
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    van den Berg, Martin
    Westerink, Remco H. S.
    Hexabromocyclododecane Inhibits Depolarization-Induced Increase in Intracellular Calcium Levels and Neurotransmitter Release in PC12 Cells2009In: Toxicological Sciences, ISSN 1096-6080, E-ISSN 1096-0929, Vol. 107, no 2, p. 490-497Article in journal (Refereed)
    Abstract [en]

    Environmental levels of the brominated flame retardant (BFR) hexabromocyclododecane (HBCD) have been increasing. HBCD has been shown to cause adverse effects on learning and behavior in mice, as well as on dopamine uptake in rat synaptosomes and synaptic vesicles. For other BFRs, alterations in the intracellular Ca2+ homeostasis have been observed. Therefore, the aim of this study was to investigate whether the technical HBCD mixture and individual stereoisomers affect the intracellular Ca2+ concentration ([Ca2+](i)) in a neuroendocrine in vitro model (PC12 cells). [Ca2+](i) and vesicular catecholamine release were measured using respectively single-cell Fura-2 imaging and amperometry. Exposure of PC12 cells to the technical HBCD mixture or individual stereoisomers did neither affect basal [Ca2+](i), nor the frequency of basal neurotransmitter release. However, exposure to HBCD (0-20 mu M) did cause a dose-dependent reduction of a subsequent depolarization-evoked increase in [Ca2+](i). This effect was apparent only when HBCD was applied at least 5 min before depolarization (maximum effect after 20 min exposure). The effects of alpha- and beta-HBCD were comparable to that of the technical mixture, whereas the inhibitory effect of gamma-HBCD was larger. Using specific blockers of L-, N- or P/Q-type voltage-gated Ca2+ channels (VGCCs) it was shown that the inhibitory effect of HBCD is not VGCC-specific. Additionally, the number of cells showing depolarization-evoked neurotransmitter release was markedly reduced following HBCD exposure. Summarizing, HBCD inhibits depolarization-evoked [Ca2+](i) and neurotransmitter release. As increasing HBCD levels should be anticipated, these findings justify additional efforts to establish an adequate exposure, hazard and risk assessment.

  • 39. Dingemans, Milou M L
    et al.
    Ramakers, Geert M J
    Gardoni, Fabrizio
    van Kleef, Regina G D M
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Di Luca, Monica
    van den Berg, Martin
    Westerink, Remco H S
    Vijverberg, Henk P M
    Neonatal exposure to brominated flame retardant BDE-47 reduces long-term potentiation and postsynaptic protein levels in mouse hippocampus.2007In: Environ Health Perspect, ISSN 0091-6765, Vol. 115, no 6, p. 865-70Article in journal (Refereed)
  • 40. Dingemans, Milou M. L.
    et al.
    van den Berg, Martin
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Westerink, Remco H. S.
    Calcium-Related Processes Involved in the Inhibition of Depolarization-Evoked Calcium Increase by Hydroxylated PBDEs in PC12 Cells2010In: Toxicological Sciences, ISSN 1096-6080, E-ISSN 1096-0929, Vol. 114, no 2, p. 302-309Article in journal (Refereed)
    Abstract [en]

    In vitro studies indicated that hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have an increased toxic potential compared to their parent congeners. An example is the OH-PBDE–induced increase of basal intracellular Ca2+ concentration ([Ca2+]i) by release of Ca2+ from endoplasmic reticulum (ER) and mitochondria and/or influx of extracellular Ca2+. ER and mitochondria regulate Ca2+ homeostasis in close association with voltage-gated Ca2+ channels (VGCCs). Therefore, effects of (OH-)PBDEs on the depolarization-evoked (100mM K+) net increase in [Ca2+]i (depolarization-evoked [Ca2+]i) were measured in neuroendocrine pheochromocytoma cells using the Ca2+-responsive dye Fura-2. OH-PBDEs dose dependently inhibited depolarization-evoked [Ca2+]i. This inhibition was potentiated by a preceding increase in basal [Ca2+]i. Especially at higher concentrations of OH-PBDEs (5–20μM), large increases in basal [Ca2+]i strongly inhibited depolarization-evoked [Ca2+]i. The inhibition appeared more sensitive to increases in basal [Ca2+]i by Ca2+ release from intracellular stores (by 3-OH-BDE-47 or 6′-OH-BDE-49) compared to those by influx of extracellular Ca2+ (by 6-OH-BDE-47 or 5-OH-BDE-47). The expected [Ca2+]i difference close to the membrane suggests involvement of Ca2+-dependent regulatory processes close to VGCCs. When coapplied with depolarization, some OH-PBDEs induced also moderate direct inhibition of depolarization-evoked [Ca2+]i. Polybrominated diphenyl ethers and methoxylated BDE-47 affected neither basal nor depolarization-evoked [Ca2+]i, except for BDE-47, which moderately increased fluctuations in basal [Ca2+]i and depolarization-evoked [Ca2+]i. These findings demonstrate that OH-PBDEs inhibit depolarization-evoked [Ca2+]i depending on preceding basal [Ca2+]i. Related environmental pollutants that affect Ca2+ homeostasis (e.g., polychlorinated biphenyls) may thus also inhibit depolarization-evoked [Ca2+]i, justifying further investigation of possible mixture effects of environmental pollutants on Ca2+ homeostasis.

  • 41.
    Eriksson, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Green, Nicholas
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Marsh, Göran
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Photochemical decomposition of fifteen polybrominated diphenyl ether congeners in methanol/water2004In: Environmental Science & Technology, ISSN 1520-5851, Vol. 38, no 11, p. 3119-3125Article in journal (Refereed)
    Abstract [en]

    Among all brominated flame retardants in use, the polybrominated diphenyl ethers (PBDEs) have been identified as being of particular environmental concern due to their global distribution and bioaccumulating properties, as observed in humans and wildlife worldwide. Still there is a need for more data on the basic characteristics of PBDEs to better understand and describe their environmental fate. Hence, the aim of this study was to investigate the photochemical degradation of PBDEs with different degrees of bromination. The photochemical degradation of 15 individual PBDEs substituted with 4−10 bromine atoms was studied in methanol/water (8:2) by UV light in the sunlight region. Nine of these were also studied in pure methanol, and four of the nine PBDEs were studied in tetrahydrofuran. The photochemical reaction rate decreased with decreasing number of bromine substituents in the molecule but also in some cases influenced by the PBDE substitution pattern. The reaction rate was dependent on the solvent in such a way that the reaction rate in a methanol/water solution was consistently around 1.7 times lower than in pure methanol and 2−3 times lower than in THF. The UV degradation half-life of decaBDE (T1/2 = 0.5 h) was more than 500 times shorter than the environmentally abundant congener 2,2‘,4,4‘-tetraBDE (T1/2 = 12 d) in methanol/water. The quantum yields in the methanol/water solution ranged from 0.1 to 0.3. The photochemical reaction of decaBDE is a consecutive debromination from ten- down to six-bromine-substituted PBDEs. Products with less than six bromines were tentatively identified as brominated dibenzofurans and traces of what was indicated as methoxylated brominated dibenzofurans.

  • 42.
    Fängström, Britta
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Athanasiadou, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Bignert, Anders
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Grandjean, Philippe
    Weihe, P
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Polybrominated diphenyl ethers and traditional organochlorine pollutants in fulmars (Fulmarus glacialis) from the Faroe Islands2005In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 60, no 7, p. 836-843Article in journal (Refereed)
    Abstract [en]

    The observed high-level burdens of organohalogens among the residents of the Faroe Islands, needs to be explained. Long-finned pilot whale (Globicephala melas) blubber and meat are known sources of environmental exposure. The present study focus on the organohalogen contamination of the fulmar (Fulmarus glacialis). The compounds quantified in fulmar muscle, fat, and egg are PCBs, DDTs, hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The dominating pollutants are the 4,4′-DDT metabolite 4,4′-DDE and the two PCB congeners, CB-153 and CB-180, which are present in geometric mean concentrations of 7100, 4700 and 2500 ng/g lipid weight (l.w.), respectively, in adult fulmar muscle. 4,4′-DDT and HCB concentrations are approximately 250 ng/g l.w., each. Concentrations in the eggs are about 50% of the fulmar muscle levels, due to differences in lipid amounts, 4% in muscle and 10% in the eggs, the exposure contribution on a fresh weight basis is almost the same. As a result, both the egg and the adult fulmar muscle may lead to a significant exposure risk, if consumed by humans.

    BDE-153, the most abundant PBDE congener in fulmar muscle, with a geometric mean concentration of 6.5 ng/g l.w., is much lower than the individual PCB congeners and 4,4′-DDE concentrations. In the adult fulmar muscle, the relative PBDE congener pattern is different from that previously observed in biota, with BDE-153 and BDE-154 as the dominating congeners, rather than BDE-47. In contrast, BDE-47 is the most abundant congener in juvenile muscle and subcutaneous fat. The ∑PBDE concentrations are almost the same in egg, muscle (adult and juvenile) and subcutaneous fat (juvenile). For the polybrominated biphenyl (BB-153) the concentrations are considerably higher in the adult bird and egg than in the juvenile bird; this is also seen for the PCB and 4,4′-DDE concentrations.

    PCB concentrations found in fulmar egg and muscle are in the same range as seen in the pilot whale, i.e. 590–5700 ng/g l.w. for CB-153. Hence humans are also exposed to PCBs at a reasonable degree via intake of fulmar and/or fulmar egg and not only via pilot whale blubber.

  • 43.
    Fängström, Britta
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Athanasiadou, Maria
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Weihe, Pál
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hydroxylated PCB Metabolites in Non-hatched Fulmar Eggs from the Faroe Islands2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 3, no 34, p. 184-187Article in journal (Refereed)
    Abstract [en]

    Thirty-six polychlorinated biphenylols (OH-PCBs) conge-ners were characterized in Fulmar (Fulmarus glacialis) eggs collected from the Faroe Islands. The seven most abundant congeners were quantified in 19 samples, and the XOH-PCB concentrations ranged between 0.92 and 4.0 ng g 1 fresh weight (f.w.). These eggs constitute a part of the traditional diet for at least a part of the population on the Faroe Islands and may contribute to the high levels of these contaminants found in the blood of pregnant Faroese women. Because the metabolites are present in the nonhatched fulmar egg, it is concluded that the OH-PCBs are transferred to the egg before laying. High levels, 3300- 18 000 ng g-1 l.w., of 2polychlorinated biphenyls (PCB) were determined in the fulmar eggs, which are a consider-able source for human exposure. The high PCB levels are a source for metabolic formation of hydroxylated PCBs.

  • 44.
    Fängström, Britta
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Odsjö, Tjelvar
    Department of Contaminant Research, Swedish Museum of Natural History, Stockholm, Sweden.
    Norén, Koidu
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Temporal trends of polybrominated diphenyl ethers and hexabromocyclododecane in milk from Stockholm mothers, 1980-2004.2008In: Molecular Nutrition & Food Research, ISSN 1613-4125, E-ISSN 1613-4133, Vol. 52, p. 187-193Article in journal (Refereed)
    Abstract [en]

    Environmental and human exposures to brominated flame retardants (BFR) have been of emerging concern since some BFR are persistent and bioaccumulative compounds. Among those, polybrominated diphenyl ethers (PBDE) have frequently been reported in low to high ng/g concentrations in human blood around the world while hexabromocyclododecane (HBCDD) only occasionally has been reported and then in the low ppb concentrations in human blood. The present study concerns PBDE congener and HBCDD concentrations in human milk from Stockholm from 1980 to 2004. HBCDD concentrations has increased four to five times since 1980 until 2002 but seems to have stabilized at this concentration in the last years (2003/04). Similarly, BDE-153 has continued to increase at least to 2001, after which it has stabilized in the mother's milk. Other PBDE congeners with four to five bromine substituents peaked 5 years earlier (1995) and are all decreasing. DecaBDE (BDE-209) is not a suitable biomarker for time trend studies according to the present results, showing no changes over time. This is likely due to its short apparent half-life in humans and poor transfer from blood to milk.

  • 45.
    Fängström, Britta
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Strid, Anna
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Grandjean, Philippe
    Weihe, Pál
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    A retrospective study of PBDEs and PCBs in human milk from the Faroe Islands2005In: Environmental health, ISSN 1476-069X, E-ISSN 1476-069X, Vol. 4, no 12Article in journal (Refereed)
    Abstract [en]

    Background

    Persistent organic pollutants (POPs) in wildlife and humans remain a cause of global concern, both in regard to traditional POPs, such as the polychlorinated biphenyls (PCBs), and emerging POPs, such as the polybrominated diphenyl ethers (PBDEs). To determine the time related concentrations, we analyzed human milk for these substances at three time points between 1987 and 1999. Polychlorobiphenylols (OH-PCBs), the dominating class of PCB metabolites, some of which are known to be strongly retained in human blood, were also included in the assessment.

    Methods

    We obtained milk from the Faroe Islands, where the population is exposed to POPs from their traditional diet (which may include pilot whale blubber). In addition to three pools, nine individual samples from the last time point were also analyzed. After cleanup, partitioning of neutral and acidic compounds, and separation of chemical classes, the analyses were carried out by gas chromatography and/or gas chromatography/mass spectrometry.

    Results

    Compared to other European populations, the human milk had high PCB concentrations, with pool concentrations of 2300 ng/g fat 1987, 1600 ng/g fat in 1994, and 1800 ng/g fat in 1999 (based on the sum of eleven major PCB congeners). The nine individual samples showed great variation in PCB concentrations. The OH-PCBs were present in trace amounts only, at levels of approximately 1% of the PCB concentrations. The PBDE concentrations showed a clear increase over time, and their concentrations in human milk from 1999 are among the highest reported so far from Europe, with results of individual samples ranging from 4.7 to 13 ng/g fat.

    Conclusion

    Although remote from pollution sources, the Faroe Islands show high concentrations of POPs in human milk, particularly PCBs, but also PBDEs. The PBDEs show increasing concentrations over time. The OH-PCB metabolites are poorly transferred to human milk, which likely is related to their acidic character.

  • 46.
    Fång, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Non-destructive method for screening for novel persistent organic contaminants in mothers´ milkManuscript (preprint) (Other academic)
  • 47.
    Fång, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Eriksson, Johan
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Chemistry.
    Widmalm, Göran
    Department of Organic Chemistry.
    Separation and NMR characterisation of Hexabromocyclododecane (HBCDD)2007In: Svensk-norsk miljökjemisk vintermöte: Dr. Holms Hotell, Geilo, 2007, p. 34-Conference paper (Other academic)
  • 48.
    Fång, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Nyberg, Elisabeth
    Swedish Museum of Natural History, Sweden.
    Bignert, Anders
    Swedish Museum of Natural History, Sweden.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in mothers' milk from Sweden, 1972-20112013In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 60, p. 224-231Article in journal (Refereed)
    Abstract [en]

    Temporal trends of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in mothers' milk are still quite rare. Data are particularly scarce when it comes to concentrations from the last decade, 2000 and onwards. The aims of the present study were to assess temporal trends of PCDD, PCDF and DL-PCB in mothers' milk from Stockholm, 1972-2011 and to compare the results with previous analysis of some of the older samples. The samples were analyzed by high resolution GC/MS and results were statistically evaluated for the periods, 1972-2011 and 2002-2011. The rate of which Sigma PCDDs, Sigma DL-PCBs and the Sigma TEQ are decreasing (on pg/g fat WHO-TEQ2005) is higher in the last decade compared to the 40 year period, 1972-2011. A similar trend is indicated, but not confirmed, for Sigma TEQ of PCDFs, probably due to too many PCDF congeners below LOQ in the period 2002-2011. Concentrations of Sigma PCDDs, PCDFs, Sigma DLPCBs and Sigma TEQ all expressed as pg/g fat on TEQ-WH02005-basis, show a statistically significant decline over time, 5.8-6.8% per year, 1972-2011. The last ten years the annual declines for Sigma PCDDs, Sigma DL-PCBs and Sigma TEQ are 92-11% and for Sigma PCDF, 5.4%. Congener specific trend analysis, 2002-2001, of PCDDs and DL-PCBs showed the same pattern, while the PCDF congeners showed no such general trend. The results from the re-analysis showed good agreement with slightly lower Sigma TEQ1998 pg/g fat concentrations in six out of seven samples and mean difference of 13% in Sigma TEQ1998. The study shows that time series can be elongated from previous studies, as long as the sample population remains the same.

  • 49.
    Fång, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Museum of Natural History, Sweden.
    Nyberg, Elisabeth
    Swedish Museum of Natural History, Sweden.
    Winnberg, Ulrika
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bignert, Anders
    Swedish Museum of Natural History, Sweden.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Toxicology Sciences Research Center (Swetox), Sweden.
    Spatial and temporal trends of the Stockholm Convention POPs in mothers' milk - a global review2015In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 22, no 12, p. 8989-9041Article, review/survey (Refereed)
    Abstract [en]

    Persistent organic pollutants (POPs) have been of environmental and health concern for more than half a century and have their own intergovernmental regulation through the Stockholm Convention, from 2001. One major concern is the nursing child's exposure to POPs, a concern that has led to a very large number of scientific studies on POPs in mothers' milk. The present review is a report on the assessment on worldwide spatial distributions of POPs and of their temporal trends. The data presented herein is a compilation based on scientific publications between 1995 and 2011. It is evident that the concentrations in mothers' milk depend on the use of pesticides and industrial chemicals defined as POPs. Polychlorinated biphenyls (PCBs) and dioxins are higher in the more industrialized areas, Europe and Northern America, whereas pesticides are higher in Africa and Asia and polybrominated diphenyl ethers (PBDEs) are reported in higher concentrations in the USA. POPs are consequently distributed to women in all parts of the world and are thus delivered to the nursing child. The review points out several major problems in the reporting of data, which are crucial to enable high quality comparisons. Even though the data set is large, the comparability is hampered by differences in reporting. In conclusion, much more detailed instructions are needed for reporting POPs in mothers' milk. Temporal trend data for POPs in mothers' milk is scarce and is of interest when studying longer time series. The only two countries with long temporal trend studies are Japan and Sweden. In most cases, the trends show decreasing concentrations of POPs in mothers' milk. However, hexabromocyclododecane is showing increasing temporal concentration trends in both Japan and Sweden.

  • 50. Gassmann, Kathrin
    et al.
    Schreiber, Timm
    Dingemans, Milou M. L.
    Krause, Guido
    Roderigo, Claudia
    Giersiefer, Susanne
    Schuwald, Janette
    Moors, Michaela
    Unfried, Klaus
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Westerink, Remco H. S.
    Rose, Christine R.
    Fritsche, Ellen
    BDE-47 and 6-OH-BDE-47 modulate calcium homeostasis in primary fetal human neural progenitor cells via ryanodine receptor-independent mechanisms2014In: Archives of Toxicology, ISSN 0340-5761, E-ISSN 1432-0738, Vol. 88, no 8, p. 1537-1548Article in journal (Refereed)
    Abstract [en]

    Polybrominated diphenyl ethers (PBDEs) are bioaccumulating flame retardants found in rising concentrations in human tissue. Epidemiological and animal studies have raised concern for their potential to induce developmental neurotoxicity (DNT). Considering the essential role of calcium homeostasis in neurodevelopment, PBDE-induced disturbance of intracellular calcium concentration ([Ca2+](i)) may underlie PBDE-induced DNT. To test this hypothesis, we investigated acute effects of BDE-47 and 6-OH-BDE-47 on [Ca2+](i) in human neural progenitor cells (hNPCs) and unraveled involved signaling pathways. Short-time differentiated hNPCs were exposed to BDE-47, 6-OH-BDE-47, and multiple inhibitors/stimulators of presumably involved signaling pathways to determine possible effects on [Ca2+](i) by single-cell microscopy with the fluorescent dye Fura-2. Initial characterization of calcium signaling pathways confirmed the early developmental stage of hNPCs. In these cells, BDE-47 (2 mu M) and 6-OH-BDE-47 (0.2 mu M) induce [Ca2+](i) transients. This increase in [Ca2+](i) is due to extracellular Ca2+ influx and intracellular release of Ca2+, mainly from the endoplasmic reticulum (ER). While extracellular Ca2+ seems to enter the cytoplasm upon 6-OH-BDE-47 by interfering with the cell membrane and independent of Ca2+ ion channels, ER-derived Ca2+ is released following activation of protein lipase C and inositol 1,4,5-trisphosphate receptor, but independently of ryanodine receptors. These findings illustrate that immature developing hNPCs respond to low concentrations of 6-OH-BDE-47 by an increase in [Ca2+](i) and provide new mechanistic explanations for such BDE-induced calcium disruption. Thus, these data support the possibility of a critical window of PBDE exposure, i.e., early human brain development, which has to be acknowledged in risk assessment.

1234 1 - 50 of 152
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf