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  • 1.
    Armitage,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Prevedouros, Kostas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Macleod, M.
    Russell, M.H.
    Buck, R.C.
    Global-Scale Fate and Transport of Perfluorocarboxylates and Perfluorocarboxylic Acids Emitted from Direct Sources using a Spatially-Resolved Multi-Species Model.2007In: SETAC 17:th Annual Meeting in Europe, Porto, Portugal: 20-24 May, 2007Conference paper (Other (popular science, discussion, etc.))
  • 2.
    Armitage,
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Prevedouros, Kostas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Macleod, M.
    Russell, M.H.
    Buck, R.C.
    Modelling the fate and transport of PFCAs emitted from direct sources using a global-scale chemical fate model.2007In: SETAC North America 28th Annual Meeting, in Milwaukee, Wisconsin, USA.: 11-15 November, 2007Conference paper (Other (popular science, discussion, etc.))
  • 3.
    Armitage, J
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, I
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, M.
    Modelling the long-term fate and transport of PFO(A) emitted from direct sources using a two-dimensional global-scale model2008In: Dioxin 2008: 17-22 August, Birmingham, UK, 2008Conference paper (Refereed)
  • 4.
    Armitage, J
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, I
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, M.
    Modelling the long-term fate and transport of PFO(A) emitted from direct sources using a two-dimensional global-scale model2008In: Organohalogen Compd., Vol. 70, p. 1438-1441Article in journal (Refereed)
  • 5.
    Armitage, J
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, I
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Persson, N.J.
    Gustafsson, Ö
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cornelissen, G
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Saloranta, T.
    Broman, D
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Næs, K.
    Black Carbon-Inclusive Modeling Approaches for Estimating the Aquatic Fate of Dibenzo-p-dioxins and Dibenzofurans2008In: Environ. Sci. Technol., Vol. 42, p. 3697-3703Article in journal (Refereed)
  • 6.
    Armitage, J
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Franco, A.
    Gomez, S.
    Cousins, I
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modeling the Potential Influence of Particle Deposition on the Accumulation of Organic Contaminants by Submerged Aquatic Vegetation2008In: Environ. Sci. Technol., Vol. 42, p. 4052-4059Article in journal (Refereed)
  • 7.
    Armitage, James
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hauck, M.
    Harbers, J.V.
    Huijbregts, M.A.J.
    Empirical evaluation of spatial and non-spatial European-scale multimedia fate models: Results and implications for chemical risk assessment.2007In: J. Environ. Monit., Vol. 9, p. 572-581Article in journal (Refereed)
  • 8.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Macleod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Additions and corrections to “Modeling the global fate and transport of perfluorooctanoic acid (PFOA) and perfluorooctanoate (PFO) emitted from direct sources using a multispecies mass balance model”2009Other (Refereed)
  • 9.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Macleod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Comparative Assessment of the Global Fate and Transport Pathways of Long-chain Perfluorocarboxylic Acids (PFCAs) and Perfluorocarboxylates (PFCs) Emitted from Direct Sources2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 15, p. 5830-5836Article in journal (Refereed)
    Abstract [en]

    A global-scale multispecies mass balance model was used to simulate the long-term fate and transport of perfluorocarboxylic acids (PFCAs) with eight to thirteen carbons (C8−C13) and their conjugate bases, the perfluorocarboxylates (PFCs). The main purpose of this study was to assess the relative long-range transport (LRT) potential of each conjugate pair, collectively termed PFC(A)s, considering emissions from direct sources (i.e., manufacturing and use) only. Overall LRT potential (atmospheric + oceanic) varied as a function of chain length and depended on assumptions regarding pKa and mode of entry. Atmospheric transport makes a relatively higher contribution to overall LRT potential for PFC(A)s with longer chain length, which reflects the increasing trend in the air−water partition coefficient (KAW) of the neutral PFCA species with chain length. Model scenarios using estimated direct emissions of the C8, C9, and C11 PFC(A)s indicate that the mass fluxes to the Arctic marine environment associated with oceanic transport are in excess of mass fluxes from indirect sources (i.e., atmospheric transport of precursor substances such as fluorotelomer alcohols and subsequent degradation to PFCAs). Modeled concentrations of C8 and C9 in the abiotic environment are broadly consistent with available monitoring data in surface ocean waters. Furthermore, the modeled concentration ratios of C8 to C9 are reconcilable with the homologue pattern frequently observed in biota, assuming a positive correlation between bioaccumulation potential and chain length. Modeled concentration ratios of C11 to C10 are more difficult to reconcile with monitoring data in both source and remote regions. Our model results for C11 and C10 therefore imply that either (i) indirect sources are dominant or (ii) estimates of direct emission are not accurate for these homologues.

  • 10.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    McLachlan, Michael
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modeling the Global Fate and Transport of Perfluorooctanoic Acid (PFOA) and Perfluorooctanoate (PFO) Emitted from Direct Sources Using a Multispecies Mass Balance Model2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 4, p. 1134-1140Article in journal (Refereed)
    Abstract [en]

    The global-scale fate and transport processes of perfluorooctanoic acid (PFOA) and perfluorooctanoate (PFO) emitted from direct sources were simulated using a multispecies mass balance model over the period 1950 to 2010. The main goal of this study was to assess the atmospheric and oceanic long-range transport potential of direct source emissions and the implications for the contamination of terrestrial and marine systems worldwide. Consistent with previous modeling studies, ocean transport was found to be the dominant pathway for delivering PFO(A) associated with direct sources to the Arctic marine environment, regardless of model assumptions. The modeled concentrations for surface ocean waters were insensitive to assumptions regarding physical−chemical properties and emission mode of entry and were in reasonable agreement with available monitoring data from the Northern Hemisphere. In contrast, model outputs characterizing atmospheric transport potential were highly sensitive to model assumptions, especially the assumed value of the acid dissociation constant (pKa). However, the complete range of model results for scenarios with different assumptions about partitioning and emissions provide evidence that the atmospheric transport of directly emitted PFO(A) can deliver this substance to terrestrial environments distant from sources. Additional studies in remote or isolated terrestrial systems may provide further insight into the scale of contamination actually attributable to direct sources.

  • 11.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Schenker, Urs
    Scheringer, Martin
    Martin, Jonathan W
    Macleod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modeling the Global Fate and Transport of Perfluorooctane Sulfonate (PFOS) and Precursor Compounds in Relation to Temporal Trends in Wildlife Exposure.2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 24, p. 9274-80Article in journal (Refereed)
    Abstract [en]

    A global-scale fate and transport model was applied to investigate the historic and future trends in ambient concentrations of perfluorooctane sulfonate (PFOS) and volatile perfluorooctane sulfonyl fluoride (POSF)-based precursor compounds in the environment. First, a global emission inventory for PFOS and its precursor compounds was estimated for the period 1957-2010. We used this inventory as input to a global-scale contaminant fate model and compared modeled concentrations with field data. The main focus of the simulations was to examine how modeled concentrations of PFOS and volatile precursor compounds respond to the major production phase-out that occurred in 2000-2002. Modeled concentrations of PFOS in surface ocean waters are generally within a factor of 5 of field data and are dominated by direct emissions of this substance. In contrast, modeled concentrations of the precursor compounds considered in this study are lower than measured concentrations both before and after the production phase-out. Modeled surface ocean water concentrations of PFOS in source regions decline slowly in response to the production phase-out while concentrations in remote regions continue to increase until 2030. In contrast, modeled concentrations of precursor compounds in both the atmosphere and surface ocean water compartment in all regions respond rapidly to the production phase-out (i.e., decline quickly to much lower levels). With respect to wildlife biomonitoring data, since precursor compounds are bioavailable and degrade to PFOS in vivo, it is at least plausible that declining trends in PFOS body burdens observed in some marine organisms are attributable to this exposure pathway. The continued increases in PFOS body burdens observed in marine organisms inhabiting other regions may reflect exposure primarily to PFOS itself, present in the environment due to production and use of this compound as well as degradation of precursor compounds.

  • 12. Arnot, Jon A.
    et al.
    Armitage, James M.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    McCarty, Lynn S.
    Wania, Frank
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Toose-Reid, Liisa
    Toward a Consistent Evaluative Framework for POP Risk Characterization2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 1, p. 97-103Article in journal (Refereed)
    Abstract [en]

    The purpose of Annex E in the Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) is to assess whether a chemical is likely, as a result of its long-range environmental transport, to lead to significant adverse human health or environmental effects, such that global action is warranted. To date, risk profiles for nominated POPs have not consistently selected assessment endpoints or completed mandated risk characterizations. An assessment endpoint hierarchy is proposed to facilitate risk characterization for the implementation of the SC. The framework is illustrated for a nominated POP, hexabromocyclododecane (HBCD), using three risk estimation methods. Based on current monitoring and toxicity data, the screening-level results indicate that humans and ecological receptors in remote regions such as the Arctic are unlikely to experience significant adverse effects (i.e., low risk) due to long-range environmental transport of HBCD. The results for birds are more uncertain than the results for fish and mammals due to the paucity of avian toxicity data. Risk characterization results for HBCD and for some listed POPs are compared to illustrate how the proposed methods can further assist decision-making and chemical management.

  • 13. Brack, Werner
    et al.
    Altenburger, Rolf
    Schueuermann, Gerrit
    Krauss, Martin
    Herraez, David Lopez
    van Gils, Jos
    Slobodnik, Jaroslav
    Munthe, John
    Gawlik, Bernd Manfred
    van Wezel, Annemarie
    Schriks, Merijn
    Hollender, Juliane
    Tollefsen, Knut Erik
    Mekenyan, Ovanes
    Dimitrov, Saby
    Bunke, Dirk
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Posthuma, Leo
    van den Brink, Paul J.
    Lopez de Alda, Miren
    Barcelo, Damia
    Faust, Michael
    Kortenkamp, Andreas
    Scrimshaw, Mark
    Ignatova, Svetlana
    Engelen, Guy
    Massmann, Gudrun
    Lemkine, Gregory
    Teodorovic, Ivana
    Walz, Karl-Heinz
    Dulio, Valeria
    Jonker, Michiel T. O.
    Jaeger, Felix
    Chipman, Kevin
    Falciani, Francesco
    Liska, Igor
    Rooke, David
    Zhang, Xiaowei
    Hollert, Henner
    Vrana, Branislav
    Hilscherova, Klara
    Kramer, Kees
    Neumann, Steffen
    Hammerbacher, Ruth
    Backhaus, Thomas
    Mack, Juliane
    Segner, Helmut
    Escher, Beate
    Umbuzeiro, Gisela de Aragao
    The SOLUTIONS project: Challenges and responses for present and future emerging pollutants in land and water resources management2015In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 503, p. 22-31Article in journal (Refereed)
    Abstract [en]

    SOLUTIONS (2013 to 2018) is a European Union Seventh Framework Programme Project (EU-FP7). The project aims to deliver a conceptual framework to support the evidence-based development of environmental policies with regard to water quality. SOLUTIONS will develop the tools for the identification, prioritisation and assessment of those water contaminants that may pose a risk to ecosystems and human health. To this end, a new generation of chemical and effect-based monitoring tools is developed and integrated with a full set of exposure, effect and risk assessment models. SOLUTIONS attempts to address legacy, present and future contamination by integrating monitoring and modelling based approaches with scenarios on future developments in society, economy and technology and thus in contamination. The project follows a solutions-oriented approach by addressing major problems of water and chemicals management and by assessing abatement options. SOLUTIONS takes advantage of the access to the infrastructure necessary to investigate the large basins of the Danube and Rhine as well as relevant Mediterranean basins as case studies, and puts major efforts on stakeholder dialogue and support. Particularly, the EU Water Framework Directive (WFD) Common Implementation Strategy (CIS) working groups, International River Commissions, and water works associations are directly supported. with consistent guidance for the early detection, identification, prioritisation, and abatement of chemicals in the water cycle. SOLUTIONS will give a specific emphasis on concepts and tools for the impact and risk assessment of complex mixtures of emerging pollutants, their metabolites and transformation products. Analytical and effect-based screening tools will be applied together with ecological assessment tools for the identification of toxicants and their impacts. The SOLUTIONS approach is expected to provide transparent and evidence-based candidates or River Basin Specific Pollutants in the case study basins and to assist future review of priority pollutants under the WFD as well as potential abatement options.

  • 14. Brack, Werner
    et al.
    Dulio, Valeria
    Ågerstrand, Marlene
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Allan, Ian
    Altenburger, Rolf
    Brinkmann, Markus
    Bunke, Dirk
    Burgess, Robert M.
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Escher, Beate I.
    Hernandez, Felix J.
    Hewitt, L. Mark
    Hilscherova, Klara
    Hollender, Juliane
    Hollert, Henner
    Kase, Robert
    Klauer, Bernd
    Lindim, Claudia
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Herraez, David Lopez
    Miege, Cecil
    Munthe, John
    O'Toole, Simon
    Posthuma, Leo
    Ruedel, Heinz
    Schaefer, Ralf B.
    Sengl, Manfred
    Smedes, Foppe
    van de Meent, Dik
    van den Brink, Paul J.
    van Gils, Jos
    van Wezel, Annemarie P.
    Vethaak, A. Dick
    Vermeirssen, Etienne
    von der Ohe, Peter C.
    Vrana, Branislav
    Towards the review of the European Union Water Framework Directive: Recommendations for more efficient assessment and management of chemical contamination in European surface water resources2017In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 576, p. 720-737Article, review/survey (Refereed)
    Abstract [en]

    Water is a vital resource for natural ecosystems and human life, and assuring a high quality of water and protecting it from chemical contamination is a major societal goal in the European Union. The Water Framework Directive (WFD) and its daughter directives are the major body of legislation for the protection and sustainable use of European freshwater resources. The practical implementation of the WFD with regard to chemical pollution has faced some challenges. In support of the upcoming WFD review in 2019 the research project SOLUTIONS and the European monitoring network NORMAN has analyzed these challenges, evaluated the state-of-the-art of the science and suggested possible solutions. We give 10 recommendations to improve monitoring and to strengthen comprehensive prioritization, to foster consistent assessment and to support solution-oriented management of surface waters. The integration of effect-based tools, the application of passive sampling for bioaccumulative chemicals and an integrated strategy for prioritization of contaminants, accounting for knowledge gaps, are seen as important approaches to advance monitoring. Including all relevant chemical contaminants in more holistic chemical status assessment, using effect-based trigger values to address priority mixtures of chemicals, to better consider historical burdens accumulated in sediments and to use models to fill data gaps are recommended for a consistent assessment of contamination. Solution-oriented management should apply a tiered approach in investigative monitoring, to identify toxicity drivers, strengthen consistent legislative frameworks and apply solutions-oriented approaches that explore risk reduction scenarios before and along with risk assessment.

  • 15.
    Bui, Thuy T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    Alves, Andreia
    Palm-Cousins, Anna
    Voorspoels, Stefan
    Covaci, Adrian
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Estimating uptake of phthalate ester metabolites into the human nail plate using pharmacokinetic modelling2017In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 100, p. 148-155Article in journal (Refereed)
    Abstract [en]

    There is a lack of knowledge regarding uptake of phthalate esters (PEs) and other chemicals into the human nail plate and thus, clarity concerning the suitability of human nails as a valid alternative matrix for monitoring longterm exposure. In particular, the relative importance of internal uptake of phthalate metabolites (from e.g. blood) compared to external uptake pathways is unknown. This study provides first insights into the partitioning of phthalate-metabolites between blood and nail using pharmacokinetic (PK) modelling and biomonitoring data from a Norwegian cohort. A previously published PK model (Lorber PK model) was used in combination with measured urine data to predict serum concentrations of DEHP and DnBP/DiBP metabolites at steady state. Then, partitioning between blood and nail was assessed assuming equilibrium conditions and treating the nail plate as a tissue, assuming a fixed lipid and water content. Although calculated as a worst-case scenario at equilibrium, the predicted nail concentrations of metabolites were lower than the biomonitoring data by factors of 44 to 1300 depending on the metabolite. It is therefore concluded that internal uptake of phthalate metabolites from blood into nail is a negligible pathway and does not explain the observed nail concentrations. Ingtead, external uptake pathways are more likely to dominate, possibly through deposition of phthalates onto the skin/nail and subsequent metabolism. Modelling gaseous diffusive uptake of PEs from air to nail revealed that this pathway is unlikely to be important. Experimental quantification of internal and external uptake pathways of phthalates and their metabolites into the human nail plate is needed to verify these modelling results. However, based on this model, human nails are not a good indicator of internal human exposure for the phthalate esters studied.

  • 16.
    Bui, Thuy T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    Giovanoulis, Georgios
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    Palm Cousins, Anna
    Magnér, Jörgen
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Human exposure, hazard and risk of alternative plasticizers to phthalate esters2016In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 541, p. 451-467Article in journal (Refereed)
    Abstract [en]

    Alternative plasticizers to phthalate esters have been used for over a decade, but data regarding emissions, human exposure and health effects are limited. Here we review 20 alternative plasticizers in current use and their human exposure, hazard and risk. Physicochemical properties are collated for these diverse alternatives and log K-OW values range over 15 orders of magnitude and log K-AW and log K-OA values over about 9 orders of magnitude. Most substances are hydrophobic with low volatility and are produced in high volumes for use in multiple applications. There is an increasing trend in the total use of alternative plasticizers in Sweden compared to common phthalate esters in the last 10 years, especially for DINCH. Evaluative indoor fate modeling reveals that most alternatives are distributed to vertical surfaces (e.g. walls or ceilings). Only TXIB and GTA are predicted to be predominantly distributed to indoor air. Human exposure data are lacking and clear evidence for human exposure only exists for DEHT and DINCH, which show increasing trends in body burdens. Human intake rates are collected and compared with limit values with resulting risk ratios below 1 except for infant's exposure to ESBO. PBT properties of the alternatives indicate mostly no reasons for concern, except that TEHPA is estimated to be persistent and TCP toxic. A caveat is that non-standard toxicological endpoint results are not available and, similar to phthalate esters, the alternatives are likely pseudo-persistent. Keydata gaps for more comprehensive risk assessment are identified and include: analytical methods to measure metabolites in biological fluids and tissues, toxicological information regarding non-standard endpoints such as endocrine disruption and a further refined exposure assessment in order to consider high risk groups such as infants, toddlers and children.

  • 17.
    Bui, Thuy T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    Xu, Fuchao
    Van den Eede, Nele
    Palm Cousins, Anna
    IVL Swedish Environmental Research Institute, Sweden.
    Covaci, Adrian
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Probing the relationship between external and internal human exposure of organophosphate flame retardants using pharmacokinetic modelling2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 230, p. 550-560Article in journal (Refereed)
    Abstract [en]

    Human external exposure (i.e. intake) of organophosphate flame retardants (PFRs) has recently been quantified, but no link has yet been established between external and internal exposure. In this study, we used a pharmacokinetic (PK) model to probe the relationship between external and internal exposure data for three PFRs (EHDPHP, TNBP and TPHP) available for a Norwegian cohort of 61 individuals from 61 different households. Using current literature on metabolism of PFRs,, we predicted the metabolite serum/urine concentrations and compared it to measured data from the study population. Unavailable parameters were estimated using a model fitting approach (least squares method) after assigning reasonable constraints on the ranges of fitted parameters. Results showed an acceptable comparison between PK model estimates and measurements (<10-fold deviation) for EHDPHP. However, a deviation of 10-1000 was observed between PM model estimates and measurements for TNBP and TPHP. Sensitivity and uncertainty analysis on the PK model revealed that EHDPHP results showed higher uncertainty than TNBP or TPHP. However, there are indications that (1) current biomarkers of exposure (i.e. assumed metabolites) for TNBP and TPHP chemicals might not be specific and ultimately affecting the outcome of the modelling and (2) some exposure pathways might be missing. Further research, such as in vivo laboratory metabolism experiments of PFRs including identification of better biomarkers will reduce uncertainties in human exposure assessment.

  • 18.
    Bui, Tuong Thuy
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Xu, Fuchao
    Van den Eede, Nele
    Palm Cousins, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Covaci, Adrian
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Probing the relationship between external and internal human exposure of organophosphate flame retardants using pharmacokinetic modellingManuscript (preprint) (Other academic)
    Abstract [en]

    Human external exposure (i.e. intake) of organophosphate flame retardants (PFRs) has recently been quantified, but no link has yet been established between external and internal exposure. In this study, we used a pharmacokinetic (PK) model to probe the relationship between external and internal exposure data for three PFRs (EHDPHP, TNBP and TPHP) available for a Norwegian cohort of 61 individuals from 61 different households. Using current literature on metabolism of PFRs, we predicted the human body burden and compared it to the measured serum and urine data for the PFRs metabolites. Unavailable parameters were estimated using a model fitting approach (least squares method) after assigning reasonable constraints on the ranges of fitted parameters. Results showed an acceptable comparison between PK model estimates and measurements (< 10-fold deviation) for EHDPHP. However, a deviation of 10-1000 was observed between PK model estimates and measurements for TNBP and TPHP. Sensitivity and uncertainty analysis on the PK model revealed that EHDPHP results showed higher uncertainty than TNBP or TPHP. However, there are indications that (1) current biomarkers of exposure (i.e. assumed metabolites) for TNBP and TPHP chemicals might not be specific and ultimately affecting the outcome of the modeling, (2) some exposure pathways might be missing. Further research, such as in vivo laboratory metabolism experiments of PFRs including identification of better biomarkers will reduce uncertainties in human exposure assessment.

  • 19. Carlsson, Pernilla
    et al.
    Breivik, Knut
    Brorström-Lundén, Eva
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Christensen, Jesper
    Grimalt, Joan O.
    Halsall, Crispin
    Kallenborn, Roland
    Abass, Khaled
    Lammel, Gerhard
    Munthe, John
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Øyvind Odland, Jon
    Pawlak, Janet
    Rautio, Arja
    Reiersen, Lars-Otto
    Schlabach, Martin
    Stemmler, Irene
    Wilson, Simon
    Wöhrnschimmel, Henry
    Polychlorinated biphenyls (PCBs) as sentinels for the elucidation of Arctic environmental change processes: a comprehensive review combined with ArcRisk project results2018In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 25, no 23, p. 22499-22528Article, review/survey (Refereed)
    Abstract [en]

    Polychlorinated biphenyls (PCBs) can be used as chemical sentinels for the assessment of anthropogenic influences on Arctic environmental change. We present an overview of studies on PCBs in the Arctic and combine these with the findings from ArcRisk-a major European Union-funded project aimed at examining the effects of climate change on the transport of contaminants to and their behaviour of in the Arctic-to provide a case study on the behaviour and impact of PCBs over time in the Arctic. PCBs in the Arctic have shown declining trends in the environment over the last few decades. Atmospheric long-range transport from secondary and primary sources is the major input of PCBs to the Arctic region. Modelling of the atmospheric PCB composition and behaviour showed some increases in environmental concentrations in a warmer Arctic, but the general decline in PCB levels is still the most prominent feature. 'Within-Arctic' processing of PCBs will be affected by climate change-related processes such as changing wet deposition. These in turn will influence biological exposure and uptake of PCBs. The pan-Arctic rivers draining large Arctic/sub-Arctic catchments provide a significant source of PCBs to the Arctic Ocean, although changes in hydrology/sediment transport combined with a changing marine environment remain areas of uncertainty with regard to PCB fate. Indirect effects of climate change on human exposure, such as a changing diet will influence and possibly reduce PCB exposure for indigenous peoples. Body burdens of PCBs have declined since the 1980s and are predicted to decline further.

  • 20.
    Cornelissen, G
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, I
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Wiberg, K.
    Tysklind, M.
    Holmström, H.
    Broman, D
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Black carbon-dominated PCDD/Fs sorption to soils at a former wood impregnation site2008In: Chemosphere, Vol. 72, p. 1455-1461Article in journal (Refereed)
  • 21.
    Cousins, I
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Berger, U
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Overview of Research on Perfluorinated Compounds at ITM2008In: Naturvårdsverket: 27 May, 2008Conference paper (Refereed)
  • 22.
    Cousins, Ian
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kong, Deguo
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Reconciling measurement and modelling studies of the sources and fate of perfluorinated carboxylates2011In: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 8, no 4, p. 339-354Article, review/survey (Refereed)
    Abstract [en]

    This study critically evaluates the recently published measurement and modelling studies of the sources and fate of perfluorinated carboxylates (PFCAs). It is concluded that modelling studies provide support to the 'direct hypothesis' for PFOA and PFNA (i.e. the global dominance of direct sources (mainly from fluoropolymer manufacturing)). Empirical evidence for the importance of direct sources of PFOA and PFNA is provided by PFNA : PFOA ratios and isomer profiles of PFOA in ocean water. However, homologue patterns of long-chain PFCAs in biota from remote regions suggest that indirect sources (mainly from precursor degradation) are proportionally more important for PFCAs with more than 10 carbons. Temporal data in biotic and abiotic media are reviewed and an increasing trend to 2000 is observed for all PFCAs, with discrepancies in time trends reported after that period. Some studies on temporal patterns report a levelling off or decline in the latter part of the 2000s for PFOA and PFNA, whereas others show a continual increase throughout the study period. Differences in temporal patterns result from the fact that some environments respond faster to emission changes than others and may thus be useful to elucidate the importance of direct and indirect sources to different regions.

  • 23.
    Cousins, Ian T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Balan, Simona A.
    Scheringer, Martin
    Weber, Roland
    Wang, Zhanyun
    Blum, Arlene
    Diamond, Miriam
    Fletcher, Tony
    Goldenman, Gretta
    Higgins, Christopher
    Lindeman, Avery E.
    Peaslee, Graham
    Trier, Xenia
    de Voogt, Pim
    Comment on Fluorotechnology Is Critical to Modern Life: The FluoroCouncil Counterpoint to the Madrid Statement2015In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 123, no 7, p. A170-A170Article in journal (Refereed)
  • 24.
    Cousins, Ian T.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Wang, Zhanyun
    Scheringer, Martin
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    The precautionary principle and chemicals management: The example of perfluoroalkyl acids in groundwater2016In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 94, p. 331-340Article, review/survey (Refereed)
    Abstract [en]

    Already in the late 1990s microgram-per-liter levels of perfluorooctane sulfonate (PFOS) were measured in water samples from areas where fire-fighting foams were used or spilled. Despite these early warnings, the problems of groundwater, and thus drinking water, contaminated with perfluoroalkyl and polyfluoroalkyl substances (PFASs) including PFOS are only beginning to be addressed. It is clear that this PFAS contamination is poorly reversible and that the societal costs of clean-up will be high. This inability to reverse exposure in a reasonable timeframe is a major motivation for application of the precautionary principle in chemicals management. We conclude that exposure can be poorly reversible; 1) due to slow elimination kinetics in organisms, or 2) due to poorly reversible environmental contamination that leads to continuous exposure. In the second case, which is relevant for contaminated groundwater, the reversibility of exposure is not related to the magnitude of a chemical's bioaccumulation potential. We argue therefore that all PFASs entering groundwater, irrespective of their perfluoroalkyl chain length and bioaccumulation potential, will result in poorly reversible exposures and risks as well as further clean-up costs for society. To protect groundwater resources for future generations, society should consider a precautionary approach to chemicals management and prevent the use and release of highly persistent and mobile chemicals such as PFASs. (C) 2016 Elsevier Ltd. All rights reserved.

  • 25. Franco, A.
    et al.
    Prevedouros, Costas
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Alli, R.
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Comparison and analysis of different approaches for estimating the human exposure to phthalate esters2007In: Environ. Internat., Vol. 33, p. 283-291Article in journal (Refereed)
  • 26.
    Gebbink, Wouter A.
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Berger, Urs
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Estimating human exposure to PFOS isomers and PFCA homologues: The relative importance of direct and indirect (precursor) exposure2015In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 74, p. 160-169Article in journal (Refereed)
    Abstract [en]

    Contributions of direct and indirect (via precursors) pathways of human exposure to perfluorooctane sulfonic acid (PFOS) isomers and perfluoroalkyl carboxylic acids (PFCAs) are estimated using a Scenario-Based Risk Assessment (SceBRA) modelling approach. Monitoring data published since 2008 (including samples from 2007) are used. The estimated daily exposures (resulting from both direct and precursor intake) for the general adult population are highest for PFOS and perfluorooctanoic acid (PFOA), followed by perfluorohexanoic add (PFHxA) and perfluorodecanoic acid (PFDA), while lower daily exposures are estimated for perfluorobutanoic acid (PFBA) and perfluorododecanoic acid (PFDoDA). The precursor contributions to the individual perfluoroalkyl acid (PFAA) daily exposures are estimated to be 11-33% for PFOS, 0.1-2.5% for PFBA, 3.7-34% for PFHxA, 13-64% for PFOA, 5.2-66% for PFDA, and 0.7-25% for PFDoDA (ranges represent estimated precursor contributions in a low- and high-exposure scenario). For PFOS, direct intake via diet is the major exposure pathway regardless of exposure scenario. For PFCAs, the dominant exposure pathway is dependent on perfluoroalkyl chain length and exposure scenario. Modelled PFOS and PFOA concentrations in human serum using the estimated intakes from an intermediate-exposure scenario are in agreement with measured concentrations in different populations. The isomer pattern of PFOS resulting from total intakes (direct and via precursors) is estimated to be enriched with linear PFOS (84%) relative to technical PFOS (70% linear). This finding appears to be contradictory to the observed enrichment of branched PFOS isomers in recent human serum monitoring studies and suggests that either external exposure is not fully understood (e.g. there are unknown precursors, missing or poorly quantified exposure pathways) and/or that there is an incomplete understanding of the isomer-specific human pharmacokinetic processes of PFOS, its precursors and intermediates.

  • 27.
    Giovanoulis, Georgios
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bui, Tuong Thuy
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Xu, Fuchao
    Covaci, Adrian
    Palm Cousins, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Magnér, Jörgen
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Multi-pathway human exposure assessment of phthalate esters and DINCHManuscript (preprint) (Other academic)
    Abstract [en]

    Phthalate esters are substances mainly used as plasticizers in various applications. Some have been restricted and phased out due to their adverse health effects and ubiquitous presence, leading to the introduction of alternative plasticizers, such as DINCH. Using a comprehensive dataset from a Norwegian study population, human exposure to DMP, DEP, DnBP, DiBP, BBzP, DEHP, DINP, DIDP, DPHP and DINCH was assessed by measuring their presence in external exposure media, allowing an estimation of the total intake, as well as the relative importance of different uptake pathways. Intake via different uptake routes, in particular inhalation, dermal absorption, and oral uptake was estimated and total intake based on all uptake pathways was compared to the back-calculated intake from biomonitoring data. Hand wipe results were used to determine dermal uptake and compared to other exposure sources such as air, dust and personal care products. Results showed that the calculated total intakes were similar, but slightly higher than those based on biomonitoring methods by 1.1 to 2.8 times (median), indicating a good understanding of important uptake pathways. The relative importance of different uptake pathways was comparable to other studies, where inhalation was important for lower molecular weight phthalates, and negligible for the higher molecular weight phthalates and DINCH. Dietary intake was the predominant exposure route for all analyzed substances. The dermal uptake assessed by hand wipes was much lower (median up to 2000 times) than the sum of dermal uptake via air, dust and personal care products and unlikely represents an integrative dermal exposure. Dermal uptake is not a well-studied exposure pathway and several research gaps (e.g. absorption fractions) remain. Based on calculated intakes, the exposure risk for the Norwegian participants to the phthalates and DINCH was lower than health based limit values. Nevertheless, exposure to alternative plasticizers, such as DPHP and DINCH, is expected to increase in the future and continuous monitoring is required.

  • 28.
    Giovanoulis, Georgios
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    Xu, Fuchao
    Papadopoulou, Eleni
    Padilla-Sanchez, Juan A.
    Covaci, Adrian
    Haug, Line S.
    Palm Cousins, Anna
    Magnér, Jörgen
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Multi-pathway human exposure assessment of phthalate esters and DINCH2018In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 112, p. 115-126Article in journal (Refereed)
    Abstract [en]

    Phthalate esters are substances mainly used as plasticizers in various applications. Some have been restricted and phased out due to their adverse health effects and ubiquitous presence, leading to the introduction of alternative plasticizers, such as DINCH. Using a comprehensive dataset from a Norwegian study population, human exposure to DMP, DEP, DnBP, DiBP, BBzP, DEHP, DINP, DIDP, DPHP and DINCH was assessed by measuring their presence in external exposure media, allowing an estimation of the total intake, as well as the relative importance of different uptake pathways. Intake via different uptake routes, in particular inhalation, dermal absorption, and oral uptake was estimated and total intake based on all uptake pathways was compared to the calculated intake from biomonitoring data. Hand wipe results were used to determine dermal uptake and compared to other exposure sources such as air, dust and personal care products. Results showed that the calculated total intakes were similar, but slightly higher than those based on biomonitoring methods by 1.1 to 3 times (median), indicating a good understanding of important uptake pathways. The relative importance of different uptake pathways was comparable to other studies, where inhalation was important for lower molecular weight phthalates, and negligible for the higher molecular weight phthalates and DINCH. Dietary intake was the predominant exposure route for all analyzed substances. Dermal uptake based on hand wipes was much lower (median up to 2000 times) than the total dermal uptake via air, dust and personal care products. Still, dermal uptake is not a well-studied exposure pathway and several research gaps (e.g. absorption fractions) remain. Based on calculated intakes, the exposure for the Norwegian participants to the phthalates and DINCH was lower than health based limit values. Nevertheless, exposure to alternative plasticizers, such as DPHP and DINCH, is expected to increase in the future and continuous monitoring is required.

  • 29.
    Gomis Ferreira, Melissa I.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nilsson, Helena
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Contribution of Direct and Indirect Exposure to Human Serum Concentrations of Perfluorooctanoic Acid in an Occupationally Exposed Group of Ski Waxers2016In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, no 13, p. 7037-7046Article in journal (Refereed)
    Abstract [en]

    The contribution of direct (i.e., uptake of perfluorooctanoic acid (PFOA) itself) and indirect (i.e., uptake of 8:2 fluorotelomer alcohol (FTOH) and metabolism to PFOA) exposure to PFOA serum concentrations was investigated using a dynamic one compartment pharmacokinetic (PK) model. The PK model was applied to six occupationally exposed ski waxers for whom direct and indirect exposures via inhalation were characterized using multiple measurements with personal air sampling devices. The model was able to predict the diverging individual temporal trends of PFOA in serum with correlation coefficients of 0.82-0.94. For the four technicians with high initial concentrations of PFOA in serum (250-1050 ng/mL), the ongoing occupational exposure (both direct and indirect) was of minor importance and net depuration of PFOA was observed throughout the ski season. An estimated average intrinsic elimination half-life of 2.4 years (1.8-3.1 years accounting for variation between technicians and model uncertainty) was derived for these technicians. The remaining two technicians, who had much lower initial serum concentrations (10-17 ng/mL), were strongly influenced by exposure during the ski season with indirect exposure contributing to 45% of PFOA serum concentrations. On the basis of these model simulations, an average metabolism yield of 0.003 (molar concentration basis; uncertainty range of 0.0006-0.01) was derived for transformation of 8:2 FTOH to PFOA. An uncertainty analysis was performed, and it was determined that the input parameters quantifying the intake of PFOA were mainly responsible for the uncertainty of the metabolism yield and the initial concentration of PFOA in serum was mainly contributing to the uncertainty of estimated serum half-lives.

  • 30.
    Gomis Ferreira, Melissa Ines
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    Borg, Daniel
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Comparing the toxic potency in vivo of long-chain perfluoroalkyl acids and fluorinated alternatives2018In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 113, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Since 2000, long-chain perfluoroalkyl acids (PFAAs) and their respective precursors have been replaced by numerous fluorinated alternatives. The main rationale for this industrial transition was that these alternatives were considered less bioaccumulative and toxic than their predecessors. In this study, we evaluated to what extent differences in toxicological effect thresholds for PFAAs and fluorinated alternatives, expressed as administered dose, were confounded by differences in their distribution and elimination kinetics. A dynamic one-compartment toxicokinetic (TK) model for male rats was constructed and evaluated using test data from toxicity studies for perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorobutane sulfonic acid (PFBS), perfluorooctanoic acid (PFOA), perfluoroctanesulfonic acid (PFOS) and ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate (GenX). Dose-response curves of liver enlargement from sub-chronic oral toxicity studies in male rats were converted to internal dose in serum and in liver to examine the toxicity ranking of PFAAs and fluorinated alternatives. Converting administered doses into equivalent serum and liver concentrations reduced the variability in the dose-response curves for PFBA, PFHxA, PFOA and GenX. The toxicity ranking using modeled serum (GenX>PFOA>PFHxA>PFBA) and liver (GenX>PFOA≈PFHxA≈PFBA) concentrations indicated that some fluorinated alternatives have similar or higher toxic potency than their predecessors when correcting for differences in toxicokinetics. For PFOS and perfluorobutane sulfonic acid (PFBS) the conversion from administered dose to serum concentration equivalents did not change the toxicity ranking. In conclusion, hazard assessment based on internal exposure allows evaluation of toxic potency and bioaccumulation potential independent of kinetics and should be considered when comparing fluorinated alternatives with their predecessors.

  • 31.
    Gomis, Melissa I.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. IVL Swedish Environmental Research Institute, Sweden.
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Mueller, Jochen F.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Historical human exposure to perfluoroalkyl acids in the United States and Australia reconstructed from biomonitoring data using population-based pharmacokinetic modelling2017In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 108, p. 92-102Article in journal (Refereed)
    Abstract [en]

    Perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) are found in the blood of humans and wildlife worldwide. Since the beginning of the 21st century, a downward trend in the human body burden, especially for PFOS and PFOA, has been observed while there is no clear temporal trend in wildlife. The inconsistency between the concentration decline in human serum and in wildlife could be indicative of a historical exposure pathway for humans linked to consumer products that has been reduced or eliminated. In this study, we reconstruct the past human exposure trends in two different regions, USA and Australia, by inferring the historical intake from cross-sectional biomonitoring data of PFOS, PFOA and PFHxS using a population-based pharmacokinetic model. For PFOS in the USA, the reconstructed daily intake peaked at 4.5 ng/kg-bw/day between 1988 and 1999 while in Australia it peaked at 4.0 ng/kg-bw/day between 1984 and 1996. For PFOA in the USA and Australia, the peak reconstructed daily intake was 1.1 ng/kg-bw/day in 1995 and 3.6 ng/kg-bw/day in 1992, respectively, and started to decline in 2000 and 1995, respectively. The model could not be satisfactorily fitted to the biomonitoring data for PFHxS within reasonable boundaries for its intrinsic elimination half-life, and thus reconstructing intakes of PFHxS was not possible. Our results indicate that humans experienced similar exposure levels and trends to PFOS and PFOA in the USA and Australia. Our findings support the hypothesis that near-field consumer product exposure pathways were likely dominant prior to the phase-out in industrialized countries. The intrinsic elimination half-life, which represents elimination processes that are common for all humans, and elimination processes unique to women (i.e., menstruation, cord-blood transfer and breastfeeding) were also investigated. The intrinsic elimination half-lives for PFOS and PFOA derived from model fitting for men were 3.8 and 2.4 years, respectively, for the USA, and 4.9 and 2 years respectively for Australia. Our results show that menstruation is a depuration pathway for PFOA for women, similarly but to a lesser extent compared to previous reports for PFOS. However menstruation, cord-blood transfer and breastfeeding together do not fully explain the apparently more rapid elimination of PFOA and PFOS by women compared to men; the intrinsic elimination half-lives in women were up to 13% lower for PFOS and up to 12% lower for PFOA compared to the corresponding half-lives in men.

  • 32.
    Gomis, Melissa Ines
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Wang, Zhanyun
    Scheringer, Martin
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    A modeling assessment of the physicochemical properties and environmental fate of emerging and novel per- and polyfluoroalkyl substances2015In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 505, p. 981-991Article in journal (Refereed)
    Abstract [en]

    Long-chain perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) are persistent, bioaccumulative, and toxic contaminants that are globally present in the environment, wildlife and humans. Phase-out actions and use restrictions to reduce the environmental release of long-chain PFCAs, PFSAs and their precursors have been taken since 2000. In particular, long-chain poly- and perfluoroalkyl substances (PFASs) are being replaced with shorter-chain homologues or other fluorinated or non-fluorinated alternatives. A key question is: are these alternatives, particularly the structurally similar fluorinated alternatives, less hazardous to humans and the environment than the substances they replace? Several fluorinated alternatives including perfluoroether carboxylic acids (PFECAs) and perfluoroether sulfonic adds (PFESAs) have beet recently identified. However, the scarcity of experimental data prevents hazard and risk assessments for these substances. In this study, we use state-of-the-art in silico tools to estimate key properties of these newly identified fluorinated alternatives. [i] COSMOtherm and SPARC ate used to estimate physicochemical properties. The US EPA EPISuite software package is used to predict degradation half-lives in air, water and soil. [ii] In combination with estimated chemical properties, a fugacity-based multimedia mass-balance unit-world model the OECD Overall Persistence (Pov) and Long-Range Transport Potential (LRTP) Screening Tool is used to assess the likely environmental fate of these alternatives. Even though the fluorinated alternatives contain some structural differences, their physicochemical properties are not significantly different from those of their predecessors. Furthermore, most of the alternatives are estimated to be similarly persistent and mobile in the environment as the long-chain PFASs. The models therefore predict that the fluorinated alternatives will become globally distributed in the environment similar to their predecessors. Although such in silico methods are coupled with uncertainties, this preliminary assessment provides enough cause for concern to warrant experimental work to better determine the properties of these fluorinated alternatives.

  • 33. Gouin, Todd
    et al.
    Armitage, James M.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Muir, Derek C. G.
    Ng, Carla A.
    Reid, Liisa
    Tao, Shu
    Influence of global climate change on chemical fate and bioaccumulation: The role of multimedia models2013In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 32, no 1, p. 20-31Article in journal (Refereed)
    Abstract [en]

    Multimedia environmental fate models are valuable tools for investigating potential changes associated with global climate change, particularly because thermodynamic forcing on partitioning behavior as well as diffusive and nondiffusive exchange processes are implicitly considered. Similarly, food-web bioaccumulation models are capable of integrating the net effect of changes associated with factors such as temperature, growth rates, feeding preferences, and partitioning behavior on bioaccumulation potential. For the climate change scenarios considered in the present study, such tools indicate that alterations to exposure concentrations are typically within a factor of 2 of the baseline output. Based on an appreciation for the uncertainty in model parameters and baseline output, the authors recommend caution when interpreting or speculating on the relative importance of global climate change with respect to how changes caused by it will influence chemical fate and bioavailability.

  • 34. Hauck, M.
    et al.
    Huijbregts, M.A.J.
    Armitage, J
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, I
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Ragas, A.M.J.
    van de Meent, D.
    Model and input uncertainty in multi-media fate modeling: Benzo[α]pyrene concentrations in Europe2008In: Chemosphere, Vol. 72, p. 959-967Article in journal (Refereed)
  • 35. Hauck, M.
    et al.
    Huijbregts, M.A.J.
    Harbers, J.V.
    Armitage,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins,
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Pistocchi, A.
    Uncertainty And Spatial Variability in European Multi-Media Fate Models.2007In: SETAC 17:th Annual Meeting in Europe, Porto, Portugal: 20-24 May, 2007Conference paper (Other (popular science, discussion, etc.))
  • 36. Hollander, A.
    et al.
    Hauck, M.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Huijbregts, M. A. J.
    Pistocchi, A.
    Ragas, A. M. J.
    van de Meent, D.
    Assessing the Relative Importance of Spatial Variability in Emissions Versus Landscape Properties in Fate Models for Environmental Exposure Assessment of Chemicals2012In: Environmental Modelling and Assessment, ISSN 1420-2026, E-ISSN 1573-2967, Vol. 17, no 6, p. 577-587Article in journal (Refereed)
    Abstract [en]

    Multimedia mass balance models differ in their treatment of spatial resolution from single boxes representing an entire region to multiple interconnected boxes with varying landscape properties and emission intensities. Here, model experiments were conducted to determine the relative importance of these two main factors that cause spatial variation in environmental chemical concentrations: spatial patterns in emission intensities and spatial differences in environmental conditions. In the model, experiments emissions were always to the air compartment. It was concluded that variation in emissions is in most cases the dominant source of variation in environmental concentrations. It was found, however, that variability in environmental conditions can strongly influence predicted concentrations in some cases, if the receptor compartments of interest are soil or water-for water concentrations particularly if a chemical has a high octanol-air partition coefficient (K-oa). This information will help to determine the required level of spatial detail that suffices for a specific regulatory purpose.

  • 37. Holmquist, H.
    et al.
    Schellenberger, Steffen
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    van der Veen, I.
    Peters, G. M.
    Leonards, P. E. G.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Properties, performance and associated hazards of state-of-the-art durable water repellent (DWR) chemistry for textile finishing2016In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 91, p. 251-264Article, review/survey (Refereed)
    Abstract [en]

    Following the phase-out of long-chain per- and polyfluoroalkyl substances (PFASs), the textile industry had to find alternatives for side-chain fluorinated polymer based durable water repellent (DWR) chemistries that incorporated long perfluoroalkyl side chains. This phase-out and subsequent substitution with alternatives has resulted in a market where both fluorinated and non-fluorinated DWRs are available. These DWR alternatives can be divided into four broad groups that reflect their basic chemistry: side-chain fluorinated polymers, silicones, hydrocarbons and other chemistries (includes dendrimer and inorganic nanoparticle chemistries). In this critical review, the alternative DWRs are assessed with regards to their structural properties and connected performance, loss and degradation processes resulting in diffuse environmental emissions, and hazard profiles for selected emitted substances. Our review shows that there are large differences in performance between the alternative DWRs, most importantly the lack of oil repellence of non-fluorinated alternatives. It also shows that for all alternatives, impurities and/or degradation products of the DWR chemistries are diffusively emitted to the environment. Our hazard ranking suggests that hydrocarbon based DWR is the most environmentally benign, followed by silicone and side-chain fluorinated polymer-based DWR chemistries. Industrial commitments to reduce the levels of impurities in silicone based and side-chain fluorinated polymer based DWR formulations will lower the actual risks. There is a lack of information on the hazards associated with DWRs, in particular for the dendrimer and inorganic nanoparticle chemistries, and these data gaps must be filled. Until environmentally safe alternatives, which provide the required performance, are available our recommendation is to choose DWR chemistry on a case-by-case basis, always weighing the benefits connected to increased performance against the risks to the environment and human health.

  • 38.
    Johansson, Jana H.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Berger, Urs
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Can the use of deactivated glass fibre filters eliminate sorption artefacts associated with active air sampling of perfluorooctanoic acid?2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 224, p. 779-786Article in journal (Refereed)
    Abstract [en]

    Experimental work was undertaken to test whether gaseous perfluorooctanoic acid (PFOA) sorbs to glassfibre filters (GFFs) during air sampling, causing an incorrect measure of the gas-particle equilibriumdistribution. Furthermore, tests were performed to investigate whether deactivation by siliconisationprevents sorption of gaseous PFOA to filter materials. An apparatus was constructed to closely simulate ahigh-volume air sampler, although with additional features allowing introduction of gaseous test compoundsinto an air stream stripped from particles. The set-up enabled investigation of the sorption ofgaseous test compounds to filter media, eliminating any contribution from particles. Experiments wereperformed under ambient outdoor air conditions at environmentally relevant analyte concentrations.The results demonstrate that gaseous PFOA sorbs to GFFs, but that breakthrough of gaseous PFOA on theGFFs occurs at trace-level loadings. This indicates that during high volume air sampling, filters do notquantitatively capture all the PFOA in the sampled air. Experiments with siliconised GFFs showed thatthis filter pre-treatment reduced the sorption of gaseous PFOA, but that sorption still occurred atenvironmentally relevant air concentrations. We conclude that deactivation of GFFs does not allow forthe separation of gaseous and particle bound perfluorinated carboxylic acids (PFCAs) during active airsampling. Consequently, the well-recognised theory that PFCAs do not prevail as gaseous species in theatmosphere may be based on biased measurements. Caution should be taken to ensure that this artefactwill not bias the conclusions of future field studies.

  • 39.
    Johansson, Jana H.
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Berger, Urs
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Norwegian Institute for Air Resarch NILU, Norway.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bignert, Anders
    Glynn, Anders
    Darnerud, Per Ola
    Temporal trends (1999-2010) of perfluoroalkyl acids in commonly consumed food items2014In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 188, p. 102-108Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to determine how dietary exposure to PFAAs has changed over the period when major production changes occurred. Archived samples (1999-2010) of eggs, milk and farmed rainbow trout were analyzed by ultra performance liquid chromatography coupled to tandem mass spectrometry. Statistically significant decreasing trends were observed for concentrations of perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS) in fish (p < 0.002 and p < 0.032, respectively) and eggs (p < 0.001 for both compounds). Concentrations of PFOS in fish and eggs decreased by a factor of 10 and 40, respectively. In eggs there was also a statistically significant decreasing trend in concentrations of perfluorooctanoic acid (PFOA). The results of this study demonstrate that PFAA concentrations in food items from agricultural food chains and aquatic food chains close to sources respond rapidly to changes in environmental emissions. Implications for the overall understanding of human exposure are discussed.

  • 40.
    Johansson, Jana H.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Shi, Yali
    Salter, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Spatial variation in the atmospheric deposition of perfluoroalkyl acids: source elucidation through analysis of isomer patterns2018In: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 20, no 7, p. 997-1006Article in journal (Refereed)
    Abstract [en]

    To evaluate the relevance of different proposed sources of perfluoroalkyl acids (PFAAs) to air, their isomer patterns were analyzed in deposition samples collected from five geographical locations: two urban sites in China (>360 km from known operational fluorochemical manufacturing facilities), one remote marine site in the Azores archipelago and two Swedish sites representing urban and background conditions. Despite variable contributions from linear perfluorooctanoic acid (PFOA) in the samples, the pattern of branched PFOA isomers was similar to those of technical standards manufactured using electrochemical fluorination (ECF). This indicates that atmospheric fate processes have little influence on the isomer profiles of PFOA and that the relative contribution of PFOA manufactured using ECF (typically 20-26% branched isomers) and telomerization (typically one single linear isomer) can be determined in atmospheric deposition samples by analyzing the proportions of branched and linear isomers. In Chinese samples, branched isomers contributed 15-25% to the total loading of PFOA, indicating that the samples were dominated by ECF PFOA. Samples in the Azores had 8-10% contribution from branched PFOA isomers, indicating an approximately equal influence of ECF and telomer sources. Only three of the samples collected in Sweden displayed a quantifiable contribution from branched PFOA isomers (8-13% of overall PFOA loading in the samples). One branched PFNA isomer was observed in samples from the marine sites. Direct manufacturing discharges, transport of sea spray aerosols and degradation of precursors are all suggested to be contributing sources, albeit to different extents, to PFAAs in air at the different geographical locations where precipitation was sampled.

  • 41.
    Johansson, Jana H.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Yan, Hong
    Berger, Urs
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Water-to-air transfer of branched and linear PFOA: Influence of pH, concentration and water type2017In: Emerging Contaminants, ISSN 2405-6650, E-ISSN 2405-6642, Vol. 3, no 1, p. 46-53Article in journal (Refereed)
    Abstract [en]

    The volatilisation of perfluorooctanoic acid (PFOA) was measured experimentally at a range of pH valuesusing a previously published laboratory method. Water-to-air transfer was studied for five structuralisomers, namely: the linear isomer (n-PFOA) and the four most commonly occurring branched isomers(3-, 4-, 5- and 6-PFOA). The influence of water concentration and water type on the pH-dependent waterto-air transfer was also investigated for n-PFOA. The water-to-air transfer was studied over the course of 48 h at pH values ranging from 0.2 to 5.5. Under all experimental conditions tested, the volatilisation ofPFOA was negligible at pH > 2.5. In experiments performed with MilliQ water, volatilisation increasedwith decreasing water pH. In experiments performed with tap water and lake water, maximum volatilisationwas observed at pH 1. The concentration of PFOA in water had no influence on the pH value atwhich water-to-air transfer was observed (i.e. at pH < 2.5) for the concentration range tested (0.1e50 mg/L PFOA in deionised water). Although the percentage of PFOA volatilised was significantly different forthe four branched isomers at low pH, volatilisation was not observed above pH 2.5 for any branchedisomer suggesting that all PFOA isomers have a low pKa. Overall, these laboratory results demonstratethat volatilisation of any structural isomer of PFOA from water is negligible at environmentally-relevantconditions. It is unlikely that PFOA isomers will be fractionated in the environment as a result of volatilisationbecause it is a process of negligible environmental relevance.

  • 42.
    Johansson, Jana
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Salter, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Navarro, Juan-Camilo
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Leck, Caroline
    Stockholm University, Faculty of Science, Department of Meteorology .
    Nilsson, Douglas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Global transport of perfluoroalkyl acids via sea spray aerosolManuscript (preprint) (Other academic)
  • 43.
    Johansson, Jana
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Shi, Yali
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Spatial variation in the atmospheric deposition of perfluoroalkyl acids: source elucidation through analysis of homologue and isomer patternsManuscript (preprint) (Other academic)
    Abstract [en]

    To evaluate the relevance of different proposed sources of perfluoroalkyl acids (PFAAs) to air, PFAA homologue and isomer patterns were analysed in precipitation collected from five geographical locations suspected to be influenced by these different types of sources. In Chinese samples, perflourooctanoic acid (PFOA) dominated the homologue patterns with concentrations exceeding those observed in European samples by a factor of 2-59. Furthermore, the isomer pattern of PFOA in Chinese samples was close to that of technical standards for PFOA manufactured using electrochemical fluorination (ECF). This finding suggests that direct manufacturing emissions of PFOA to air dominate the loading of PFOA in air in these regions of China. The PFAA homologue pattern observed in precipitation sampled in Stockholm was dominated by perfluorohexanoic acid, perfluorononanoic acid (PFNA) and PFOA. The isomer pattern of PFOA was to a large degree linear indicating that telomer-based sources, i.e. most likely atmospheric degradation of fluorotelomer alcohols, dominate in this urban area. Samples from the Azores, a group of islands located in the open Atlantic, were dominated by perfluorooctane sulfonic acid (PFOS), PFNA and PFOA, which displayed an isomer patttern suggestive of input from both ECF and telomer sources. A similar pattern was observed in precipitation collected during winter months at a rural site on the Swedish west coast, while samples taken at this site during summer displayed homologue and isomer patterns more like those observed in Stockholm. We hypothesize that the contribution from ECF PFOA observed in European samples was due to influence from sea spray aerosols and this requires further detailed investigation.

  • 44.
    Kong, Deguo
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modelling the influence of climate change on the chemical concentrations in the Baltic Sea region with the POPCYCLING-Baltic modelManuscript (preprint) (Other (popular science, discussion, etc.))
  • 45.
    Kong, Deguo
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modelling the influence of climate change on the chemical concentrations in the Baltic Sea region with the POPCYCLING-Baltic model2014In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 110, p. 31-40Article in journal (Refereed)
    Abstract [en]

    The effect of projected future changes in temperature, wind speed, precipitation and particulate organic carbon on concentrations of persistent organic chemicals in the Baltic Sea regional environment is evaluated using the POPCYCLING-Baltic multimedia chemical fate model. Steady-state concentrations of hypothetical perfectly persistent chemicals with property combinations that encompass the entire plausible range for non-ionizing organic substances are modelled under two alternative climate change scenarios (IPCC A2 and B2) and compared to a baseline climate scenario. The contributions of individual climate parameters are deduced in model experiments in which only one of the four parameters is changed from the baseline scenario. Of the four selected climate parameters, temperature is the most influential, and wind speed is least. Chemical concentrations in the Baltic region are projected to change by factors of up to 3.0 compared to the baseline climate scenario. For chemicals with property combinations similar to legacy persistent organic pollutants listed by the Stockholm Convention, modelled concentration ratios between two climate change scenarios and the baseline scenario range from factors of 0.5 to 2.0. This study is a first step toward quantitatively assessing climate change-induced changes in the environmental concentrations of persistent organic chemicals in the Baltic Sea region.

  • 46.
    Kong, Deguo
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hayley, Hung
    Environment Canada.
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Statistical analysis of long-term atmospheric monitoring data of persistent organic pollutants in the atmosphere demonstrates effectiveness of control measures but not climate change signalsManuscript (preprint) (Other (popular science, discussion, etc.))
  • 47.
    Kong, Deguo
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hung, Hayley
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Statistical Analysis of Long-Term Monitoring Data for Persistent Organic Pollutants in the Atmosphere at 20 Monitoring Stations Broadly Indicates Declining Concentrations2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 21, p. 12492-12499Article in journal (Refereed)
    Abstract [en]

    During recent decades concentrations of persistent organic pollutants (POPs) in the atmosphere have been monitored at multiple stations worldwide. We used three statistical methods to analyze a total of 748 time series of selected POPs in the atmosphere to determine if there are statistically significant reductions in levels of POPs that have had control actions enacted to restrict or eliminate manufacture, use and emissions. Significant decreasing trends were identified in 560 (75%) of the 748 time series collected from the Arctic, North America, and Europe, indicating that the atmospheric concentrations of these POPs are generally decreasing, consistent with the overall effectiveness of emission control actions. Statistically significant trends in synthetic time series could be reliably identified with the improved Mann-Kendall (iMK) test and the digital filtration (DF) technique in time series longer than 5 years. The temporal trends of new (or emerging) POPs in the atmosphere are often unclear because time series are too short. A statistical detrending method based on the iMK test was not able to identify abrupt changes in the rates of decline of atmospheric POP concentrations encoded into synthetic time series.

  • 48.
    Kong, Deguo
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Li, Zhe
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Effects of input uncertainty and variability on the modelled environmental fate of organic pollutants under global climate change scenarios2013In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 93, no 9, p. 2086-2093Article in journal (Refereed)
    Abstract [en]

    Global climate change (GCC) is expected to influence the fate, exposure and risks of organic pollutants to wildlife and humans. Multimedia chemical fate models have been previously applied to estimate how GCC affects pollutant concentrations in the environment and biota, but previous studies have not addressed how uncertainty and variability of model inputs affect model predictions. Here, we assess the influence of climate variability and chemical property uncertainty on future projections of environmental fate of six polychlorinated biphenyl congeners under different GCC scenarios using a spreadsheet version of the ChemCAN model and the Crystal Ball® software. Regardless of emission mode, results demonstrate: (i) uncertainty in degradation half-lives dominates the variance of modelled absolute levels of PCB congeners under GCC scenarios; (ii) when the ratios of predictions under GCC to predictions under present day climate are modelled, climate variability dominates the variance of modelled ratios; and (iii) the ratios also indicate a maximum of about a factor of 2 change in the long-term average environmental concentrations due to GCC that is forecasted between present conditions and the period between 2080 and 2099. We conclude that chemical property uncertainty does not preclude assessing relative changes in a GCC scenario compared to a present-day scenario if variance in model outputs due to chemical properties and degradation half-lives can be assumed to cancel out in the two scenarios.

  • 49. Koponen, Jani
    et al.
    Winkens, Kerstin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Airaksinen, Riikka
    Berger, Urs
    Vestergren, Robin
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Karvonen, Anne M.
    Pekkanen, Juha
    Kiviranta, Hannu
    Longitudinal trends of per- and polyfluoroalkyl substances in children’s serumManuscript (preprint) (Other academic)
  • 50. Land, Magnus
    et al.
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Herzke, Dorte
    Johansson, Jana
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Martin, Jonathan W.
    What is the effect of phasing out long-chain per- and polyfluoroalkyl substances on the concentrations of perfluoroalkyl acids and their precursors in the environment? A systematic review protocol2015In: Environmental Evidence, ISSN 2047-2382, E-ISSN 2047-2382, Vol. 4, article id 3Article in journal (Refereed)
    Abstract [en]

    Background

    There is a growing concern in Sweden and elsewhere that continued emissions of per- and polyfluoroalkyl substances (PFASs) may cause environmental as well as human health effects. PFASs are a broad class of man-made substances that have been produced and used in both commercial products and industrial processes for more than 60 years. Although the production and use of some PFASs has been phased-out in some parts of the world, it is not known what effect these actions to date have had on PFAS concentrations in the environment. Owing to the wide diversity of PFASs, it is difficult to generalize their properties, environmental fate and production histories. However, the strength and stability of the C-F bond renders the perfluoroalkyl moieties resistant to heat and environmental degradation. Several PFASs are now occurring even in very remote areas in large parts of the world, but the environmental transport and fate of substances within this group is not well understood. A systematic review may be able to determine whether the concentrations of these substances in different environments are changing in any particular direction with time, and whether the phase-outs have had any effects on the concentration trends.

    Methods

    Searches for primary research studies reporting on temporal variations of PFAS concentrations in the environment will be performed in the scientific literature as well as in other reports. Relevant samples include both abiotic and biological samples including humans. No particular time, document type, language or geographical constraints will be applied. Two authors will screen all retrieved articles. Double screening of about 10% of the articles will be performed by all authors at both title/abstract and full-text levels. Kappa tests will be used to test if the screening is consistent. Relevant articles will be critically appraised by four authors (double checking of 25% of the articles). Quality assessment will focus on selection bias, dating of samples, sample integrity and analytical procedures. Data synthesis will be based on statistical analysis of temporal concentration trends.

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