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  • 51.
    Beer, Christian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Permafrost Sub-grid Heterogeneity of Soil Properties Key for 3-D Soil Processes and Future Climate Projections2016Ingår i: Frontiers in Earth Science, ISSN 2296-6463, Vol. 4, artikel-id 81Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There are massive carbon stocks stored in permafrost-affected soils due to the 3-D soil movement process called cryoturbation. For a reliable projection of the past, recent and future Arctic carbon balance, and hence climate, a reliable concept for representing cryoturbation in a land surface model (LSM) is required. The basis of the underlying transport processes is pedon-scale heterogeneity of soil hydrological and thermal properties as well as insulating layers, such as snow and vegetation. Today we still lack a concept of how to reliably represent pedon-scale properties and processes in a LSM. One possibility could be a statistical approach. This perspective paper demonstrates the importance of sub-grid heterogeneity in permafrost soils as a pre-requisite to implement any lateral transport parametrization. Representing such heterogeneity at the sub-pixel size of a LSM is the next logical step of model advancements. As a result of a theoretical experiment, heterogeneity of thermal and hydrological soil properties alone lead to a remarkable initial sub-grid range of subsoil temperature of 2C, and active-layer thickness of 150 cm in East Siberia. These results show the way forward in representing combined lateral and vertical transport of water and soil in LSMs.

  • 52.
    Beer, Christian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Porada, Philipp
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Ekici, Altug
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Bjerknes Centre for Climate Research, Norway.
    Brakebusch, Matthias
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Effects of short-term variability of meteorological variables on soil temperature in permafrost regions2018Ingår i: The Cryosphere, ISSN 1994-0416, E-ISSN 1994-0424, Vol. 12, nr 2, s. 741-757Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Effects of the short-term temporal variability of meteorological variables on soil temperature in northern high-latitude regions have been investigated. For this, a process-oriented land surface model has been driven using an artificially manipulated climate dataset. Short-term climate variability mainly impacts snow depth, and the thermal diffusivity of lichens and bryophytes. These impacts of climate variability on insulating surface layers together substantially alter the heat exchange between atmosphere and soil. As a result, soil temperature is 0.1 to 0.8 degrees C higher when climate variability is reduced. Earth system models project warming of the Arctic region but also increasing variability of meteorological variables and more often extreme meteorological events. Therefore, our results show that projected future increases in permafrost temperature and active-layer thickness in response to climate change will be lower (i) when taking into account future changes in short-term variability of meteorological variables and (ii) when representing dynamic snow and lichen and bryophyte functions in land surface models.

  • 53.
    Bejgarn, Sofia
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    MacLeod, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Bogdal, Christian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Institute for Chemical and Bioengineering, ETH Zurich, Switzerland.
    Breitholtz, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Toxicity of leachate from weathering plastics: An exploratory screening study with Nitocra spinipes2015Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 132, s. 114-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Between 60% and 80% of all marine litter is plastic. Leachate from plastics has previously been shown to cause acute toxicity in the freshwater species Daphnia magna. Here, we present an initial screening of the marine environmental hazard properties of leachates from weathering plastics to the marine harpacticoid copepod [Crustacea] Nitocra spinipes. Twenty-one plastic products made of different polymeric materials were leached and irradiated with artificial sunlight. Eight of the twenty-one plastics (38%) produced leachates that caused acute toxicity. Differences in toxicity were seen for different plastic products, and depending on the duration of irradiation. There was no consistent trend in how toxicity of leachate from plastics changed as a function of irradiation time. Leachate from four plastics became significantly more toxic after irradiation, two became significantly less toxic and two did not change significantly. Analysis of leachates from polyvinyl chloride (PVC) by liquid chromatography coupled to a full-scan high-resolution mass spectrometer showed that the leachates were a mixture of substances, but did not show evidence of degradation of the polymer backbone. This screening study demonstrates that leachates from different plastics differ in toxicity to N. spinipes and that the toxicity varies under simulated weathering.

  • 54. Bennike, Niels H.
    et al.
    Palangi, Lina
    Bråred Christensson, Johanna
    Nilsson, Ulrika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Zachariae, Claus
    Johansen, Jeanne D.
    Hagvall, Lina
    Allergic contact dermatitis caused by hydroperoxides of limonene and dose-response relationship-A repeated open application test (ROAT) study2019Ingår i: Contact Dermatitis, ISSN 0105-1873, E-ISSN 1600-0536, Vol. 80, nr 4, s. 208-216Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Contact allergy to oxidized limonene, with hydroperoxides of limonene (Lim-OOHs) as the main allergens, is common. However, high proportions of weak positive and doubtful patch test reactions have been reported. Objectives: To determine the clinical relevance, elicitation threshold and dose-response relationship of Lim-OOHs in individuals with a positive or doubtful patch test reaction to standard Lim-OOHs 0.3% pet. Methods: A multicentre 3-week double-blind vehicle-controlled repeated open application test (ROAT) study with a simulated fine fragrance containing Lim-OOHs at 1260, 420 and 140 ppm, equal to a dose/area per application of Lim-OOHs of 3.0, 0.99 and 0.33 mu g/cm(2), was performed. Results: Among 11 subjects allergic to Lim-OOHs, 11 (100%), 7 (64%), and 3 (27%), respectively, reacted to the applied doses. No reactions were seen in 17 healthy controls exposed to the highest dose. This difference in reactivity was statistically significant (P < 0.0001). Among 13 subjects with doubtful patch test reactions to Lim-OOHs, two (15%) had positive ROAT reactions to the highest Lim-OOH dose applied (P = 0.36 as compared with controls). Conclusions: Contact allergy to Lim-OOHs is of clinical relevance in patients with positive patch test reactions. A doubtful patch test reaction to Lim-OOHs 0.3% pet. can be of clinical relevance.

  • 55.
    Bergman, Åke
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Swedish toxicology sciences research center, Sweden; Karolinska Institutet, Sweden; Tongji University, China.
    Bignert, AndersQiu, YanlingTongji University, China.Huang, QinghuiYin, Daqiang
    Chemical Pollution Challenges in the Yangtze River Delta: Communication Brief2019Samlingsverk (redaktörskap) (Övrigt vetenskapligt)
  • 56.
    Bergman, Åke
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Swedish toxicology sciences research center, Sweden; Karolinska Institutet, Sweden; Tongji University, China.
    Bignert, AndersQiu, YanlingStockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Tongji University, China.Yin, GeStockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Chemical Pollution - Challenges in the Yangtze River Delta, China: A 2017 Sino-Swedish Research Report2017Samlingsverk (redaktörskap) (Övrigt vetenskapligt)
    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. 

  • 57.
    Bergman, Åke
    et al.
    Karolinska Institutet, Sweden.
    Drakvik, Elina
    Karolinska Institutet, Sweden.
    Rudén, Christina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Gennings, Chris
    Mount Sinai School of Medicine, New York, USA.
    EDC-MixRisk Policiy Brief2019Övrigt (Övrigt vetenskapligt)
  • 58. Beronius, A.
    et al.
    Ågerstrand, Marlene
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Making the most of expert judgment in hazard and risk assessment of chemicals2017Ingår i: Toxicology Research, ISSN 2045-452X, E-ISSN 2045-4538, Vol. 6, nr 5, s. 571-577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Evaluation of the reliability and relevance of toxicity and ecotoxicity studies is an integral step in the assessment of the hazards and risks of chemicals. This evaluation is inherently reliant on expert judgment, which often leads to differences between experts' conclusions regarding how individual studies can contribute to the body of evidence. The conclusions of regulatory assessment, such as establishing safe exposure levels for humans and the environment and calculations of margins of exposure, may have large consequences for which chemicals are permitted on the market and their allowed uses. It is therefore important that such assessments are based on all reliable and relevant scientific data, and that assessment principles and assumptions, such as expert judgment, are transparently applied. It is not possible nor desirable to completely eliminate expert judgment from the evaluation of (eco) toxicity studies. However, it is desirable to introduce measures that increase structure and transparency in the evaluation process so as to provide scientifically robust risk assessments that can be used for regulatory decision making. In this article we present results from workshop exercises with Nordic experts to illustrate how experts' evaluations regarding the reliability and relevance of (eco) toxicity studies for risk assessment may vary and discuss methods intended to promote structure and transparency in the evaluation process.

  • 59. Beronius, Anna
    et al.
    Molander, Linda
    Zilliacus, Johanna
    Rudén, Christina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Hanberg, Annika
    Testing and refining the Science in Risk Assessment and Policy (SciRAP) web-based platform for evaluating the reliability and relevance of in vivo toxicity studies2018Ingår i: Journal of Applied Toxicology, ISSN 0260-437X, E-ISSN 1099-1263, Vol. 38, nr 12, s. 1460-1470Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Science in Risk Assessment and Policy (SciRAP) web-based platform was developed to promote and facilitate structure and transparency in the evaluation of ecotoxicity and toxicity studies for hazard and risk assessment of chemicals. The platform includes sets of criteria and a colour-coding tool for evaluating the reliability and relevance of individual studies. The SciRAP method for evaluating in vivo toxicity studies was first published in 2014 and the aim of the work presented here was to evaluate and develop that method further. Toxicologists and risk assessors from different sectors and geographical areas were invited to test the SciRAP criteria and tool on a specific set of in vivo toxicity studies and to provide feedback concerning the scientific soundness and user-friendliness of the SciRAP approach. The results of this expert assessment were used to refine and improve both the evaluation criteria and the colour-coding tool. It is expected that the SciRAP web-based platform will continue to be developed and enhanced to keep up to date with the needs of end-users.

  • 60.
    Beronius, Anna
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Vandenberg, Laura N.
    Using systematic reviews for hazard and risk assessment of endocrine disrupting chemicals2016Ingår i: Reviews in endocrine and metabolic disorders (Print), ISSN 1389-9155, E-ISSN 1573-2606, Vol. 16, nr 4, s. 273-287Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The possibility that endocrine disrupting chemicals (EDCs) in our environment contribute to hormonally related effects and diseases observed in human and wildlife populations has caused concern among decision makers and researchers alike. EDCs challenge principles traditionally applied in chemical risk assessment and the identification and assessment of these compounds has been a much debated topic during the last decade. State of the science reports and risk assessments of potential EDCs have been criticized for not using systematic and transparent approaches in the evaluation of evidence. In the fields of medicine and health care, systematic review methodologies have been developed and used to enable objectivity and transparency in the evaluation of scientific evidence for decision making. Lately, such approaches have also been promoted for use in the environmental health sciences and risk assessment of chemicals. Systematic review approaches could provide a tool for improving the evaluation of evidence for decision making regarding EDCs, e.g. by enabling systematic and transparent use of academic research data in this process. In this review we discuss the advantages and challenges of applying systematic review methodology in the identification and assessment of EDCs.

  • 61. Bianchi, Federica
    et al.
    Agazzi, Silvia
    Riboni, Nicolò
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. University of Parma, Italy.
    Erdal, Nejla
    Hakkarainen, Minna
    Ilag, Leopold
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Anzillotti, Luca
    Andreoli, Roberta
    Moroni, Fabrizio
    Cecchi, Rossana
    Careri, Maria
    Novel sampling-substrates for the determination of new psychoactive substances in oral fluid by desorption electrospray ionization-high resolution mass spectrometryManuskript (preprint) (Övrigt vetenskapligt)
  • 62. Bianchi, Federica
    et al.
    Agazzi, Silvia
    Riboni, Nicolò
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Università di Parma, Italy.
    Erdal, Nejla
    Hakkarainen, Minna
    Ilag, Leopold L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Anzillotti, Luca
    Andreoli, Roberta
    Marezza, Francesca
    Moroni, Fabrizio
    Cecchi, Rossana
    Careri, Maria
    Novel sample-substrates for the determination of new psychoactive substances in oral fluid by desorption electrospray ionization-high resolution mass spectrometry2019Ingår i: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 202, s. 136-144Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    A reliable screening and non invasive method based on the use of microextraction by packed sorbent coupled with desorption electrospray ionization-high resolution mass spectrometry was developed and validated for the detection of new psychoactive substances in oral fluid. The role of different sample substrates in enhancing signal intensity and stability was evaluated by testing the performances of two polylactide-based materials, i.e. non-functionalized and functionalized with carbon nanoparticles, and a silica-based material compared to commercially available polytetrafluorethylene supports. The best results were achieved by using the non-functionalized polylactide substrates to efficiently ionize compounds in positive ionization mode, whereas the silica coating proved to be the best choice for operating in negative ionization mode. LLOQs in the low mu g/L, a good precision with CV% always lower than 16% and RR% in the 83( +/- 4)-120( +/- 2)% range, proved the suitability of the developed method for the determination of the analytes in oral fluid. Finally, the method was applied for screening oral fluid samples for the presence of psychoactive substances during private parties, revealing mephedrone in only one sample out of 40 submitted to analysis.

  • 63. Bianchi, Federica
    et al.
    Riboni, Nicolò
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. University of Parma, Italy.
    Termopoli, Veronica
    Mendez, Lucia
    Medina, Isabel
    Ilag, Leopold
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Cappiello, Achille
    Careri, Maria
    MS-Based Analytical Techniques: Advances in Spray-Based Methods and EI-LC-MS Applications2018Ingår i: Journal of Analytical Methods in Chemistry, ISSN 2090-8865, E-ISSN 2090-8873, Vol. 2018, artikel-id 1308167Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. (is review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.

  • 64. Bianchi, Federico
    et al.
    Kurtén, Theo
    Riva, Matthieu
    Mohr, Claudia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Rissanen, Matti P.
    Roldin, Pontus
    Berndt, Torsten
    Crounse, John D.
    Wennberg, Paul O.
    Mentel, Thomas F.
    Wildt, Jürgen
    Junninen, Heikki
    Jokinen, Tuija
    Kulmala, Markku
    Worsnop, Douglas R.
    Thornton, Joel A.
    Donahue, Neil
    Kjaergaard, Henrik G.
    Ehn, Mikael
    Highly Oxygenated Organic Molecules (HOM) from Gas-Phase Autoxidation Involving Peroxy Radicals: A Key Contributor to Atmospheric Aerosol2019Ingår i: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 119, nr 6, s. 3472-3509Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Highly oxygenated organic molecules (HOM) are formed in the atmosphere via autoxidation involving peroxy radicals arising from volatile organic compounds (VOC). HOM condense on pre-existing particles and can be involved in new particle formation. HOM thus contribute to the formation of secondary organic aerosol (SOA), a significant and ubiquitous component of atmospheric aerosol known to affect the Earths radiation balance. HOM were discovered only very recently, but the interest in these compounds has grown rapidly. In this Review, we define HOM and describe the currently available techniques for their identification/quantification, followed by a summary of the current knowledge on their formation mechanisms and physicochemical properties. A main aim is to provide a common frame for the currently quite fragmented literature on HOM studies. Finally, we highlight the existing gaps in our understanding and suggest directions for future HOM research.

  • 65. Bidleman, Terry
    et al.
    Agosta, Kathleen
    Andersson, Agneta
    Brorström-Lundén, Eva
    Haglund, Peter
    Hansson, Katarina
    Laudon, Hjalmar
    Newton, Seth
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Nygren, Olle
    Ripszam, Matyas
    Tysklind, Mats
    Wiberg, Karin
    Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment2015Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, s. 472-483Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011-2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069-2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air-sea gas exchange and bulk'' (precipitation ? dry particle) deposition, resulting in net gains of 53 and 46 kg year(-1) for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg year(-1) for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment.

  • 66.
    Bighiu, Maria Alexandra
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Use and environmental impact of antifouling paints in the Baltic Sea2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Biocide-based antifouling (AF) paints are the most common method for preventing biofouling, i.e. the growth of algae, barnacles and other organisms on boat hulls. AF paints for leisure boats are predominantly based on copper (Cu) as the main biocide, with zinc (Zn) present as a pigment and stabilizer. Both metals are released from the paint matrix into the water column, leading to contamination of marinas which typically have only limited water exchange. Thus, the aim of this PhD thesis was to describe the use of AF paints in different regions in Sweden, as well as the associated environmental consequences with regard to contamination of the environment and toxicity to non-target aquatic snails. Using a recently developed X-ray fluorescence application, high levels of Cu were detected on boats moored in freshwaters, despite a more than 20-year-old ban, as well as high levels of tin (Sn) on 10 % of the boats, indicating the presence of (old) tributyltin paints (TBT), which might pose an environmental risk and a health hazard for people performing the paint scraping (paper 1). In addition, very high levels of Cu and Zn were measured in the biofouling material collected from the boat hulls, and this is problematic because the biofouling is commonly disposed of on the soil in boatyards at the end of each season. No difference was found in the amount of biofouling on boats coated with Cu or biocide-free paints, which implies that Cu might be currently overused in areas of low salinity and low barnacle density (paper 2). This work also introduces the use of a new species for ecotoxicological field experiments, the snail Theodoxus fluviatilis. Chronic field experiments (paper 3) revealed 6-fold increases in snail mortality, negative growth and up to 67-fold decreased reproduction in marinas, compared to areas not impacted by boating (‘reference areas’). Moreover, a higher prevalence of snails with histopathological alterations (e.g. necrosis of gills, gonads, midgut gland and parasite infestation, among others) was observed in the marinas, compared to the reference areas (paper 4). Statistical modelling indicated that the majority of the toxic effects were best predicted by the metals, most likely originating from AF paints. The results presented in this thesis depict some important aspects of AF paint use in brackish water and highlight the necessity of implementing a suitable management practice for the heavily contaminated biofouling waste in order to minimize the risk to soils. In addition, the evidence of toxicity to snails in marinas can be used as a basis to increase the public understanding of the impact of recreational boating and encourage people to choose less toxic alternatives to AF paints.

  • 67.
    Bighiu, Maria Alexandra
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Eriksson-Wiklund, Ann-Kristin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Eklund, Britta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Biofouling of leisure boats as a source of metal pollution2017Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 24, nr 1, s. 997-1006Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The release of harmful metals from antifouling paints to water bodies is a well-known problem. In this study, we measured both the amount of biofouling growth on leisure boats during one season as well as the concentration of metals accumulated by the biofouling matrix. Furthermore, the efficiency of antifouling paints and mechanical boat cleaning as well as the effect of hull colour on biofouling were evaluated. Unlike paint residues, biofouling waste has never been regarded as a source of metal contamination and has previously been neglected in the scientific literature. Our results revealed that the biofouling waste contained very high concentrations of metals, up to 28,000 mg copper/kg dw and 171,000 mg zinc/kg dw, which exceeds the guidance values for least sensitive land use in Sweden by factors of 140 and 340, respectively. This observation is important because the contaminated biofouling waste is commonly disposed of in boatyard soils at the end of each season, thus increasing the levels of metal pollution. Moreover, there was no significant difference in the amount of biofouling if the boats were coated with copper or zinc containing paints or no paint at all, indicating that biocide paints might not be necessary in low-salinity areas such as the Stockholm archipelago. For boats that were not painted at all during the season, those washed on boat washers (mechanically) had on average half of the amount of biofouling compared to boats that were not cleaned mechanically. The results of the study indicate the importance of proper management of biofouling waste as well as the use of more environmentally friendly removal methods for biofouling such as boat washers.

  • 68.
    Bighiu, Maria Alexandra
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Gorokhova, Elena
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Carney Almroth, Bethanie
    Eriksson Wiklund, Ann-Kristin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Metal contamination in harbours impacts life-history traits and metallothionein levels in snails2017Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 7, artikel-id e0180157Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Harbours with limited water exchange are hotspots of contaminant accumulation. Antifouling paints (AF) contribute to this accumulation by leaching biocides that may affect non-target species. In several leisure boat harbours and reference areas in the Baltic Sea, chronic exposure effects were evaluated using caging experiments with the snail Theodoxus fluviatilis. We analysed variations in ecologically relevant endpoints (mortality, growth and reproduction) in concert with variation in metallothionein-like proteins (MTLP) levels. The latter is a biomarker of exposure to metals, such as copper (Cu) and zinc (Zn), which are used in AF paints as active ingredient and stabilizer, respectively. In addition, environmental samples (water, sediment) were analysed for metal (Cu and Zn) and nutrient (total phosphorous and nitrogen) concentrations. All life-history endpoints were negatively affected by the exposure, with higher mortality, reduced growth and lower fecundity in the harbours compared to the reference sites. Metal concentrations were the key explanatory variables for all observed adverse effects, suggesting that metal-driven toxicity, which is likely to stem from AF paints, is a source of anthropogenic stress for biota in the harbours.

  • 69.
    Bighiu, Maria Alexandra
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Watermann, Burkard
    Guo, Xueli
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Carney Almroth, Bethanie
    Eriksson-Wiklund, Ann-Kristin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Mortality and histopathological effects in harbour-transplanted snails with different exposure histories2017Ingår i: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 190, s. 11-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Contaminants are important stressors in the aquatic environment and may exert selective pressures on organisms. We hypothesized that snails originating from a metal-contaminated habitat (B) would have increased tolerance to harbour contaminants (e.g. metals from antifouling paints), compared to snails originating from a relatively clean habitat (A). We assessed tolerance to metals in terms of survival and histopathological alterations after 2, 4 and 8 weeks of in situ exposure in three Baltic Sea boat harbours and three reference sites. We also hypothesized that any potential tolerance to contaminants would be associated with differences in genetic diversity between the two snail populations (evaluated as mitochondrial cytochrome c oxidase subunit I, COI). The results show that snails from population A survived to a higher extent compared to population B, possibly indicating either a lack of adaptation to metals in snails B or impaired health condition due to contaminant pre-exposure or a higher resilience of snails A. Moreover, the genetic diversity of COI was low within each population and did not differ between populations. In general, 83% of all the types of histopathological alterations (e.g. lysis and necrosis of gonads and digestive gland or granulocytoma and phagocytosis in the storage tissue, among others) had a higher probability of occurrence among harbour-exposed snails compared to reference exposed snails, regardless of snail population origin. The only significant difference in histological effects between the two populations was in the frequency of parasite infestations and shell fouling, both being larger for population A than B. Interestingly, the rate of parasite infestations was higher for males than females from population A, whereas no sexual dichotomy was observed for population B. Our results show that exposure to harbour contaminants causes both lethal and sublethal toxicity to snails, and the association between many of the toxic responses and metals substantiates that antifouling substances contribute to the observed effects, although there is a large proportion of variation in our data that remains unexplained.

  • 70.
    Bighiu, Maria
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Gorokhova, Elena
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Carney Almroth, Bethanie
    Eriksson-Wiklund, Ann-Kristin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Metal contamination in harbours impacts life-history traits and metallothionein levels in snailsManuskript (preprint) (Övrigt vetenskapligt)
  • 71.
    Bighiu, Maria
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Watermann, Burkard
    Guo, Xueli
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Carney Almroth, Bethanie
    Eriksson-Wiklund, Ann-Kristin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Mortality and histopathological effects in harbour-transplanted snails with different exposure historiesManuskript (preprint) (Övrigt vetenskapligt)
  • 72.
    Bikkina, Srinivas
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Andersson, August
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Kirillova, Elena N.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Holmstrand, Henry
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Tiwari, Suresh
    Srivastava, A. K.
    Bisht, D. S.
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Air quality in megacity Delhi affected by countryside biomass burning2019Ingår i: Nature Sustainability, ISSN 2398-9629, Vol. 2, nr 3, s. 200-205Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    South Asian megacities are strong sources of regional air pollution. Delhi is a key hotspot of health-and climate-impacting black carbon (BC) emissions, affecting environmental sustainability in densely populated northern India. Effective mitigation of BC impact is hampered by highly uncertain emission source estimates. Here, we use dual-carbon isotope fingerprints (delta C-13/Delta C-14) of BC to constrain the seasonal source variability in Delhi. These measurements show that lower BC concentrations in summer are predominantly from fossil fuel sources (similar to 83%). However, large-scale open burning of post-harvest crop residue/wood in nearby rural regions is contributing to severe haze pollution in Delhi during winter and autumn (similar to 42 +/- 17%). Hence, the common conception that megacities affect their surroundings is here amended or seasonally reversed. Therefore, to combat the severe air pollution problems in Delhi and the environmental quality of northern India, current urban efforts need to be complemented with countryside regional mitigation.

  • 73.
    Bikkina, Srinivas
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Andersson, August
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Ram, Kirpa
    Sarin, M. M.
    Sheesley, Rebecca J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Kirillova, Elena N.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Rengarajan, R.
    Sudheer, A. K.
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Carbon isotope-constrained seasonality of carbonaceous aerosol sources from an urban location (Kanpur) in the Indo-Gangetic Plain2017Ingår i: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 122, nr 9, s. 4903-4923Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Indo-Gangetic Plain (IGP) in northern India, Pakistan, and Bangladesh is a major source of carbonaceous aerosols in South Asia. However, poorly constrained seasonality of their sources over the IGP leads to large uncertainty in climate and health effects. Here we present a first data set for year-round radiocarbon (C-14) and stable carbon (C-13)-based source apportionment of total carbon (TC) in ambient PM10 (n = 17) collected from an urban site (Kanpur: 26.5 degrees N, 80.3 degrees E) in the IGP during January 2007 to January 2008. The year-round C-14-based fraction biomass (f(bio-TC)) estimate at Kanpur averages 777% and emphasizes an impact of biomass burning emissions (BBEs). The highest f(bio-TC) (%) is observed in fall season (October-November, 856%) followed by winter (December-February, 804%) and spring (March-May, 758%), while lowest values are found in summer (June-September, 69 +/- 2%). Since biomass/coal combustion and vehicular emissions mostly contribute to carbonaceous aerosols over the IGP, we predict C-13(TC) (C-13(pred)) over Kanpur using known C-13 source signatures and the measured C-14 value of each sample. The seasonal variability of C-13(obs)-C-13(pred) versus C-14(TC) together with air mass back trajectories and Moderate Resolution Imaging Spectroradiometer fire count data reveal that carbonaceous aerosols in winter/fall are significantly influenced by atmospheric aging (downwind transport of crop residue burning/wood combustion emissions in the northern IGP), while local sources (wheat residue combustion/vehicular emissions) dominate in spring/summer. Given the large temporal and seasonal variability in sources and emission strength of TC over the IGP, C-14-based constraints are, thus, crucial for reducing their uncertainties in carbonaceous aerosol budgets in climate models.

  • 74.
    Bikkina, Srinivas
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Andersson, August
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Sarin, M. M.
    Sheesley, R. J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Kirillova, E.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Rengarajan, R.
    Sudheer, A. K.
    Ram, K.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Banaras Hindu University, India.
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Dual carbon isotope characterization of total organic carbon in wintertime carbonaceous aerosols from northern India2016Ingår i: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 121, nr 9, s. 4797-4809Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Large-scale emissions of carbonaceous aerosols (CA) from South Asia impact both regional climate and air quality, yet their sources are not well constrained. Here we use source-diagnostic stable and radiocarbon isotopes (delta C-13 and Delta C-14) to characterize CA sources at a semiurban site (Hisar: 29.2 degrees N, 75.2 degrees E) in the NW Indo-Gangetic Plain (IGP) and a remote high-altitude location in the Himalayan foothills (Manora Peak: 29.4 degrees N, 79.5 degrees E, 1950 m above sea level) in northern India during winter. The Delta C-14 of total aerosol organic carbon (TOC) varied from -178% to -63% at Hisar and from -198% to -1% at Manora Peak. The absence of significant differences in the C-14-based fraction biomass of TOC between Hisar (0.81 +/- 0.03) and Manora Peak (0.82 +/- 0.07) reveals that biomass burning/biogenic emissions (BBEs) are the dominant sources of CA at both sites. Combining this information with d13C, other chemical tracers (K+/OC and SO42-/EC) and air mass back trajectory analyses indicate similar source regions in the IGP (e.g., Punjab and Haryana). These results highlight that CA from BBEs in the IGP are not only confined to the atmospheric boundary layer but also extend to higher elevations of the troposphere, where the synoptic-scale circulations could substantially influence their abundances both to the Himalayas and over the downwind oceanic regions such as the Indian Ocean. Given the vast emissions of CA from postharvest crop residue combustion practices in the IGP during early Northeast Monsoon, this information is important for both improved process and model understanding of climate and health effects, as well as in guiding policy decision aiming at reducing emissions.

  • 75. Bilde, Merete
    et al.
    Barsanti, Kelley
    Booth, Murray
    Cappa, Christopher D.
    Donahue, Neil M.
    Emanuelsson, Eva U.
    McFiggans, Gordon
    Krieger, Ulrich K.
    Marcolli, Claudia
    Tropping, David
    Ziemann, Paul
    Barley, Mark
    Clegg, Simon
    Dennis-Smither, Benjamin
    Hallquist, Mattias
    Hallquist, Asa M.
    Khlystov, Andrey
    Kulmala, Markku
    Mogensen, Ditte
    Percival, Carl J.
    Pope, Francis
    Reid, Jonathan P.
    da Silva, M. A. V. Ribeiro
    Rosenoern, Thomas
    Salo, Kent
    Soonsin, Vacharapom Pia
    Yli-Juuti, Taina
    Prisle, Nonne L.
    Pagels, Joakim
    Rarey, Juergen
    Zardini, Alessandro A.
    Riipinen, Ilona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Saturation Vapor Pressures and Transition Enthalpies of Low-Volatility Organic Molecules of Atmospheric Relevance: From Dicarboxylic Acids to Complex Mixtures2015Ingår i: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 115, nr 10, s. 4115-4156Artikel, forskningsöversikt (Refereegranskat)
  • 76. Bischoff, Juliane
    et al.
    Sparkes, Robert B.
    Selver, Ayca Dogrul
    Spencer, Robert G. M.
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Semiletov, Igor P.
    Dudarev, Oleg V.
    Wagner, Dirk
    Rivkina, Elizaveta
    van Dongen, Bart E.
    Talbot, Helen M.
    Source, transport and fate of soil organic matter inferred from microbial biomarker lipids on the East Siberian Arctic Shelf2016Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 13, nr 17, s. 4899-4914Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Siberian Arctic contains a globally significant pool of organic carbon (OC) vulnerable to enhanced warming and subsequent release by both fluvial and coastal erosion processes. However, the rate of release, its behaviour in the Arctic Ocean and vulnerability to remineralisation is poorly understood. Here we combine new measurements of microbial biohopanoids including adenosylhopane, a lipid associated with soil microbial communities, with published glycerol dialkyl glycerol tetraethers (GDGTs) and bulk delta C-13 measurements to improve knowledge of the fate of OC transported to the East Siberian Arctic Shelf (ESAS). The microbial hopanoid-based soil OC proxy R'(soil) ranges from 0.0 to 0.8 across the ESAS, with highest values nearshore and decreases offshore. Across the shelf R'(soil) displays a negative linear correlation with bulk delta C-13 measurements (r(2) = -0.73, p = < 0 : 001). When compared to the GDGT-based OC proxy, the branched and isoprenoid tetraether (BIT) index, a decoupled (non-linear) behaviour on the shelf was observed, particularly in the Buor-Khaya Bay, where the R'(soil) shows limited variation, whereas the BIT index shows a rapid decline moving away from the Lena River outflow channels. This reflects a balance between delivery and removal of OC from different sources. The good correlation between the hopanoid and bulk terrestrial signal suggests a broad range of hopanoid sources, both fluvial and via coastal erosion, whilst GDGTs appear to be primarily sourced via fluvial transport. Analysis of ice complex deposits (ICDs) revealed an average R'(soil) of 0.5 for the Lena Delta, equivalent to that of the Buor-Khaya Bay sediments, whilst ICDs from further east showed higher values (0.6-0.85). Although R'(soil) correlates more closely with bulk OC than the BIT, our understanding of the endmembers of this system is clearly still incomplete, with variations between the different East Siberian Arctic regions potentially reflecting differences in environmental conditions (e.g. temperature, pH), but other physiological controls on microbial bacteriohopanepolyol (BHP) production under psychrophilic conditions are as yet unknown.

  • 77. Bisht, D. S.
    et al.
    Tiwari, S.
    Dumka, U. C.
    Srivastava, A. K.
    Safai, P. D.
    Ghude, S. D.
    Chate, D. M.
    Rao, P. S. P.
    Ali, K.
    Prabhakaran, T.
    Panickar, A. S.
    Soni, V. K.
    Attri, S. D.
    Tunved, Peter
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Chakrabarty, R. K.
    Hopke, P. K.
    Tethered balloon-born and ground-based measurements. of black carbon and particulate profiles within the lower troposphere during the foggy period in Delhi, India2016Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 573, s. 894-905Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ground and vertical profiles of particulate matter (PM) were mapped as part of a pilot study using a Tethered balloon within the lower troposphere (1000 m) during the foggy episodes in the winter season of 2015-16 in New Delhi, India. Measurements of black carbon (BC) aerosol and PM <2.5 and 10 mu m (PM2.5 &PM-10 respectively) concentrations and their associated particulate optical properties along with meteorological parameters were made. The mean concentrations of PM2.5, PM10, BC370 (nm), and BC880 nm were observed to be 146.8 +/- 42.1, 245.4 +/- 65.4, 30.3 +/- 122, and 24.1 +/- 103 mu g m(-3), respectively. The mean value of PM2.5 was similar to 12 times higher than the annual US-EPA air quality standard. The fraction of BC in PM2.5 that contributed to absorption in the shorter visible wavelengths (BC370 nm) was-21%. Compared to clear days, the ground level mass concentrations of PM2.5 and BC370 nm particles were substantially increased (59% and 24%, respectively) during the foggy episode. The aerosol light extinction coefficient (sigma(ext)) value was much higher (mean: 610 Mm(-1)) during the lower visibility (foggy) condition. Higher concentrations of PM2.5 (89 mu g m(-3)) and longer visible wavelength absorbing BC880 am (25.7 mu g m(-3)) particles were observed up to 200 m. The BC880 nm and PM2.5 aerosol concentrations near boundary layer (1 km) were significantly higher (similar to 1.9 and 12 mu g m(-3)), respectively. The BC (i.e BCtot) aerosol direct radiative forcing (DRF) values were estimated at the top of the atmosphere (TOA), surface (SFC), and atmosphere (ATM) and its resultant forcing were- 75.5 Wm(-2) at SFC indicating the cooling effect at the surface. A positive value (20.9 Wm(-2)) of BC aerosol DRF at TOA indicated the warming effect at the top of the atmosphere over the study region. The net DRF value due to BC aerosol was positive (96.4 Wm(-2)) indicating a net warming effect in the atmosphere. The contribution of fossil and biomass fuels to the observed BC aerosol DRF values was -78% and-22%, respectively. The higher mean atmospheric heating rate (2.71 K clay(-1)) by BC aerosol in the winter season would probably strengthen the temperature inversion leading to poor dispersion and affecting the formation of clouds. Serious detrimental impacts on regional climate due to the high concentrations of BC and PM (especially PM2.5) aerosol are likely based on this study and suggest the need for immediate, stringent measures to improve the regional air quality in the northern India.

  • 78. Bjurshammar, N.
    et al.
    Malmqvist, S.
    Johannsen, G.
    Boström, E. A.
    Fyrestam, Jonas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Östman, Conny
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Johannsen, A.
    The Effect of Local Phototherapy on Gingival Inflammation - A Randomized Controlled StudyManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Aim: To investigate if a toothbrush with incorporated 450 nm LEDs used in daily oral care can reduce dental plaque and gingival inflammation.

    Materials and methods: An 8-week single blinded randomized clinical trial comparing toothbrushes with and without 450 nm blue LED light emission including 48 subjects. Clinical parameters of interest were plaque index (PI), gingival index (GI) and bleeding on probing (BOP). Analyzes were also made on Interleukin-1β (IL), IL-6, IL -8, and Tumor necrosis factor alpha.

    Results: A significant reduction in PI, GI and BOP was detected within the groups from baseline to follow-up visit, but no statistical differences between subjects using a toothbrush with 450 nm blue light and a toothbrush without light. Significant decreases in the levels of both MMP-8 and TIMP-1 in saliva, and IL-1b and IL-8 in GCF for the blue light toothbrush groups.

    Conclusion: A toothbrush with 450 nm LEDs did not yield any statistical significant adjunctive effect to tooth brushing with regard to reduction in gingival inflammation. A larger decrease in PI for the blue light toothbrush compared to control was found at a significance level of p=0.058. To get an optimal phototherapeutic effect we suggest that a wavelength of 405 nm should be used in future studies.

  • 79. Bogdal, Christian
    et al.
    Alsberg, Tomas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Diefenbacher, Pascal S.
    MacLeod, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Berger, Urs
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Fast Quantification of Chlorinated Paraffins in Environmental Samples by Direct Injection High-Resolution Mass Spectrometry with Pattern Deconvolution2015Ingår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 87, nr 5, s. 2852-2860Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chlorinated paraffins (CPs) are high production volume chemicals, but data about their environmental fate are scarce. CP mixtures composed of thousands of isomers represent a major challenge for quantification at low levels in environmental samples. Here, we present a novel analytical method for analysis of short-chain, medium-chain, and long-chain CPs in a single injection, that also yields information about congener group pattern. Our detection method is based on direct injection into an atmospheric pressure chemical ionization source operated in negative ion mode under chlorine-enhanced conditions, followed by quadrupole time-of-flight high-resolution mass spectrometry (APCI-qTOF-HRMS) operated in full-scan mode. A mathematical algorithm is applied to deconvolute the CP patterns in the analyzed samples into a linear combination of patterns of technical CP mixtures and to quantify CPs using technical mixtures as external calibration standards. For CP mixtures with known composition, the new method provided concentrations that were within a factor of 1.2 of the target value. Accuracies for CPs spiked to sediment and fish extracts were between 91% and 123%. Concentrations determined in unspiked field samples were within a factor of 5 for short-chain CPs and a factor of 16 for medium-chain CPs of results obtained with an independent method based on gas chromatography/electron capture negative ionization high-resolution mass spectrometry (GC/ECNI-HRMS). The presented APCI-qTOF-HRMS pattern deconvolution method is an interesting alternative for CP analysis in environmental samples. It is particularly sensitive for medium- and long-chain CPs and has the advantage of being extremely fast (instrumental analysis time, less than 1 min).

  • 80.
    Bolinius, Damien Johann
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Methods to measure mass transfer kinetics, partition ratios and atmospheric fluxes of organic chemicals in forest systems2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Vegetation plays an important role in the partitioning, transport and fate of hydrophobic organic contaminants (HOCs) in the environment. This thesis aimed at addressing two key knowledge gaps in our understanding of how plants exchange HOCs with the atmosphere: (1) To improve our understanding of the uptake of HOCs into, and transfer through, leaves of different plant species which can significantly influence the transport and fate of HOCs in the environment; and (2) To evaluate an experimental approach to measure fluxes of HOCs in the field. The methods presented in papers I, II and III contribute to increasing our understanding of the fate and transport of HOCs in leaves by offering straightforward ways of measuring mass transfer coefficients through leaves and partition ratios of HOCs between leaves, leaf lipids and lipid standards and reference materials like water, air and olive oil. The passive dosing study in paper III in particular investigated the role of the composition of the organic matter extracted from leaves in determining the capacity of the leaves to hold chemicals and found no large differences between 7 different plant species, even though literature data on leaf/air partition ratios (Kleaf/air) varies over 1-3 orders of magnitude. In paper IV we demonstrated that the modified Bowen ratio method can be extended to measure fluxes of persistent organic pollutants (POPs) if the fluxes do not change direction over the course of the sampling period and are large enough to be measured. This approach thus makes it possible to measure fluxes of POPs that usually require sampling times of days to weeks to exceed method detection limits. The experimental methods described in this thesis have the potential to support improved parameterization of multimedia models, which can then be evaluated against fluxes measured in the field using the modified Bowen ratio approach.

  • 81.
    Bolinius, Damien Johann
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Jahnke, Annika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Helmholtz Centre for Environmental Research (UFZ), Germany.
    MacLeod, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Comparison of eddy covariance and modified Bowen ratio methods for measuring gas fluxes and implications for measuring fluxes of persistent organic pollutants2016Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 16, nr 8, s. 5315-5322Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Semi-volatile persistent organic pollutants (POPs) cycle between the atmosphere and terrestrial surfaces; however measuring fluxes of POPs between the atmosphere and other media is challenging. Sampling times of hours to days are required to accurately measure trace concentrations of POPs in the atmosphere, which rules out the use of eddy covariance techniques that are used to measure gas fluxes of major air pollutants. An alternative, the modified Bowen ratio (MBR) method, has been used instead. In this study we used data from FLUXNET for CO2 and water vapor (H2O) to compare fluxes measured by eddy covariance to fluxes measured with the MBR method using vertical concentration gradients in air derived from averaged data that simulate the long sampling times typically required to measure POPs. When concentration gradients are strong and fluxes are unidirectional, the MBR method and the eddy covariance method agree within a factor of 3 for CO2, and within a factor of 10 for H2O. To remain within the range of applicability of the MBR method, field studies should be carried out under conditions such that the direction of net flux does not change during the sampling period. If that condition is met, then the performance of the MBR method is neither strongly affected by the length of sample duration nor the use of a fixed value for the transfer coefficient.

  • 82.
    Bolinius, Damien Johann
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Stockholm Univ, Dept Environm Sci & Analyt Chem ACES, Svante Arrhenius Vag 8, SE-11418 Stockholm, Sweden.
    MacLeod, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Iadaresta, Francesco
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Holmbäck, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Lipidor AB, Karolinska Institutet Science Park, Sweden.
    Jahnke, Annika
    Sorptive Capacities of Nonpolymeric Plant Lipids for Hydrophobic Chemicals Determined by Passive Dosing2019Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, nr 3, s. 1278-1286Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vegetation plays an important role in the partitioning, transport, and fate of semivolatile hydrophobic organic chemicals (HOCs) in the environment. Leaf/air partition ratios (K-leaf/air) of HOCs are highly variable for different plant species. The differences cannot be fully explained by the fraction of lipids in the leaves or the thickness of the cuticle. Our goal was to elucidate the importance of non polymeric lipids in determining K-leaf/air To do this, we extracted organic matter from 7 plant species using solvents that do not extract the polymeric lipids cutin and cutan, to yield extractable organic matter (EOM). We used passive dosing to determine the partition ratios of selected HOCs between the EOM of the leaves and our reference lipid, olive oil (K-EOM/olive oil) In addition, we measured analogous partition ratios for three lipid standards. Proton nuclear magnetic resonance (NMR) spectroscopy was used to characterize the composition of lipids. Differences in K-EOM/olive oil of two polychlorinated biphenyls and four chlorinated benzenes were below a factor of 2 in the plant species studied, indicating that the reported differences in K-leaf/air are not caused by differences in the sorptive capacities of nonpolymeric lipids or that our EOM is not representative of all nonpolymeric leaf lipids.

  • 83.
    Bolinius, Dämien J.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholms universitets Östersjöcentrum.
    Sobek, Anna
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Löf, Marie F.
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholms universitets Östersjöcentrum.
    Undeman, Emma
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholms universitets Östersjöcentrum.
    Evaluating the consumption of chemical products and articles as proxies for diffuse emissions to the environment2018Ingår i: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 20, nr 10, s. 1427-1440Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study we have evaluated the use of consumption of manufactured products (chemical products and articles) in the EU as proxies for diffuse emissions of chemicals to the environment. The content of chemical products is relatively well known. However, the content of articles (products defined by their shape rather than their composition) is less known and currently has to be estimated from chemicals that are known to occur in a small set of materials, such as plastics, that are part of the articles. Using trade and production data from Eurostat in combination with product composition data from a database on chemical content in materials (the Commodity Guide), we were able to calculate trends in the apparent consumption and in-use stocks for 768 chemicals in the EU for the period 2003-2016. The results showed that changes in the apparent consumption of these chemicals over time are smaller than in the consumption of corresponding products in which the chemicals are present. In general, our results suggest that little change in chemical consumption has occurred over the timespan studied, partly due to the financial crisis in 2008 which led to a sudden drop in the consumption, and partly due to the fact that each of the chemicals studied is present in a wide variety of products. Estimated in-use stocks of chemicals show an increasing trend over time, indicating that the mass of chemicals in articles in the EU, that could potentially be released to the environment, is increasing. The quantitative results from this study are associated with large uncertainties due to limitations of the available data. These limitations are highlighted in this study and further underline the current lack of transparency on chemicals in articles. Recommendations on how to address these limitations are also discussed.

  • 84.
    Bolinius, Dämien Johann
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    MacLeod, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    McLachlan, Michael S.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Mayer, Philipp
    Jahnke, Annika
    A passive dosing method to determine fugacitycapacities and partitioning properties of leaves2016Ingår i: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 18, s. 1325-1332Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The capacity of leaves to take up chemicals from the atmosphere and water in fl uences how contaminantsare transferred into food webs and soil. We provide a proof of concept of a passive dosing method tomeasure leaf/polydimethylsiloxane partition ratios ( K leaf/PDMS ) for intact leaves, using polychlorinatedbiphenyls (PCBs) as model chemicals. Rhododendron leaves held in contact with PCB-loaded PDMSreached between 76 and 99% of equilibrium within 4 days for PCBs 3, 4, 28, 52, 101, 118, 138 and 180.Equilibrium K leaf/PDMS extrapolated from the uptake kinetics measured over 4 days ranged from 0.075(PCB 180) to 0.371 (PCB 3). The K leaf/PDMS data can readily be converted to fugacity capacities of leaves( Z leaf ) and subsequently leaf/water or leaf/air partition ratios ( K leaf/water and K leaf/air ) using partitioning datafrom the literature. Results of our measurements are within the variability observed for plant/air partitionratios ( K plant/air ) found in the literature. Log K leaf/air from this study ranged from 5.00 (PCB 3) to 8.30(PCB 180) compared to log K plant/air of 3.31 (PCB 3) to 8.88 (PCB 180) found in the literature. The methodwe describe could provide data to characterize the variability in sorptive capacities of leaves that wouldimprove descriptions of uptake of chemicals by leaves in multimedia fate models.

  • 85.
    Bolinius, Dämien
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    MacLeod, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Iadaresta, Francesco
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Holmbäck, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Jahnke, Annika
    Sorptive capacities of leaf lipids for hydrophobic organic chemicals: Lipid characterization and passive dosing experimentsManuskript (preprint) (Övrigt vetenskapligt)
  • 86. Bornehag, Carl-Gustaf
    et al.
    Kitraki, Efthymia
    Stamatakis, Antonios
    Panagiotidou, Emily
    Rudén, Christina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Shu, Huan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Lindh, Christian
    Ruegg, Joelle
    Gennings, Chris
    A Novel Approach to Chemical Mixture Risk Assessment—Linking Data from Population-Based Epidemiology and Experimental Animal Tests2019Ingår i: Risk Analysis, ISSN 0272-4332, E-ISSN 1539-6924, Vol. 39, nr 10, s. 2259-2271Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Humans are continuously exposed to chemicals with suspected or proven endocrine disrupting chemicals (EDCs). Risk management of EDCs presents a major unmet challenge because the available data for adverse health effects are generated by examining one compound at a time, whereas real-life exposures are to mixtures of chemicals. In this work, we integrate epidemiological and experimental evidence toward a whole mixture strategy for risk assessment. To illustrate, we conduct the following four steps in a case study: (1) identification of single EDCs (bad actors)-measured in prenatal blood/urine in the SELMA study-that are associated with a shorter anogenital distance (AGD) in baby boys; (2) definition and construction of a typical mixture consisting of the bad actors identified in Step 1; (3) experimentally testing this mixture in an in vivo animal model to estimate a dose-response relationship and determine a point of departure (i.e., reference dose [RfD]) associated with an adverse health outcome; and (4) use a statistical measure of sufficient similarity to compare the experimental RfD (from Step 3) to the exposure measured in the human population and generate a similar mixture risk indicator (SMRI). The objective of this exercise is to generate a proof of concept for the systematic integration of epidemiological and experimental evidence with mixture risk assessment strategies. Using a whole mixture approach, we could find a higher rate of pregnant women under risk (13%) when comparing with the data from more traditional models of additivity (3%), or a compound-by-compound strategy (1.6%).

  • 87.
    Bosch, Carme
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Andersson, August
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Kruså, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Bandh, Cecilia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Hovorkova, Ivana
    Klanova, Jana
    Knowles, Timothy D. J.
    Pancost, Richard D.
    Evershed, Richard P.
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Source Apportionment of Polycyclic Aromatic Hydrocarbons in Central European Soils with Compound-Specific Triple Isotopes (delta C-13, Delta C-14, and delta H-2)2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 13, s. 7657-7665Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper reports the first study applying a triple-isotope approach for source apportionment of polycyclic aromatic hydrocarbons (PAHs). The C-13/C-12, and H-2/H-1 isotope ratios of PAHs were determined in forest soils from mountainous areas of the Czech Republic, European Union. Statistical modeling applying a Bayesian Markov chain Monte Carlo (MCMC) framework to the environmental triple isotope PAR data and an end-member PAR isotope database allowed comprehensive accounting of uncertainties and quantitative constraints on the PAR sources among biomass combustion, liquid fossil fuel combustion, and coal combustion at low and high temperatures. The results suggest that PAHs in this central European region had a clear predominance of coal combustion sources (75 +/- 6%; uncertainties represent 1 SD), mainly coal pyrolysis at low temperature (similar to 650 degrees C; 61 +/- 8%). Combustion of liquid fossil fuels and biomass represented 16 +/- 3 and 9 + 3% of the total PAR burden (Sigma PAH(14)), respectively. Although some soils were located close to potential PAR point sources, the source distribution was within a narrow range throughout the region. These observation-based top-down constraints on sources of environmental PARS provide a reference for both improved bottom-up emission inventories and guidance for efforts to mitigate PAR emissions.

  • 88. Boucher, Justin M.
    et al.
    Cousins, Ian T.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Scheringer, Martin
    Hungerbühler, Konrad
    Wang, Zhanyun
    Toward a Comprehensive Global Emission Inventory of C-4-C-10 Perfluoroalkanesulfonic Acids (PFSAs) and Related Precursors: Focus on the Life Cycle of C-6- and C-10-Based Products2019Ingår i: Environmental Science and Technology Letters, E-ISSN 2328-8930, Vol. 6, nr 1, s. 1-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A first global emission inventory of C-4-C-10 perfluoroalkanesulfonic acids (PFSAs) released during the life cycle of perfluorohexanesulfonyl fluoride (PHxSF)- and perfluorodecanesulfonyl fluoride (PDSF)-based products is presented. This study complements previous research on emissions of PFSAs that focused largely on the life cycle of perfluorooctanesulfonyl fluoride (POSF) and its derivatives. It reviews and integrates existing information about the life cycle of PHxSF, PDSF, and their derivatives; the limited data available in the public domain point to potentially significant global production, uses, and releases of these substances. Between 1958 and 2015, ranges of total emissions of perfluorohexanesulfonic acid (PFHxS) and perfluorodecanesulfonic acid (PFDS) are estimated to be 120-1022 and 38-378 metric tons, respectively. With the new emission estimates as inputs in a global multimedia environmental fate model (CliMoChem), the model-derived environmental concentrations well capture the reported field concentrations, providing strong support for the plausibility of the developed emission inventories. The results highlight the ongoing environmental exposure to these substances and the need for more detailed data in the public domain about their production levels and uses.

  • 89.
    Bourgeois, Quentin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Ekman, Annica M. L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Igel, Matthew R.
    Krejci, Radovan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Ubiquity and impact of thin mid-level clouds in the tropics2016Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, artikel-id 12432Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Clouds are crucial for Earth's climate and radiation budget. Great attention has been paid to low, high and vertically thick tropospheric clouds such as stratus, cirrus and deep convective clouds. However, much less is known about tropospheric mid-level clouds as these clouds are challenging to observe in situ and difficult to detect by remote sensing techniques. Here we use Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite observations to show that thin mid-level clouds (TMLCs) are ubiquitous in the tropics. Supported by high-resolution regional model simulations, we find that TMLCs are formed by detrainment from convective clouds near the zero-degree isotherm. Calculations using a radiative transfer model indicate that tropical TMLCs have a cooling effect on climate that could be as large in magnitude as the warming effect of cirrus. We conclude that more effort has to be made to understand TMLCs, as their influence on cloud feedbacks, heat and moisture transport, and climate sensitivity could be substantial.

  • 90.
    Bourgeois, Quentin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Ekman, Annica M. L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Krejci, Radovan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Aerosol transport over the Andes from the Amazon Basin to the remote Pacific Ocean: A multiyear CALIOP assessment2015Ingår i: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 120, nr 16, s. 8411-8425Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Six years (200702012) of data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite instrument were used to investigate the vertical distribution and transport of aerosols over the tropical South American continent and the southeast Pacific Ocean. The multiyear aerosol extinction assessment indicates that aerosols, mainly biomass burning particles emitted during the dry season in the Amazon Basin, are lifted in significant amounts over the Andes. The aerosols are mainly transported in the planetary boundary layer between the surface and 2 km altitude with an aerosol extinction maximum near the surface. During the transport toward the Andes, the aerosol extinction decreases at a rate of 0.02 km(-1) per kilometer of altitude likely due to dilution and deposition processes. Aerosols reaching the top of the Andes, at altitudes typically between 4 and 5 km, are entrained into the free troposphere (FT) over the southeast Pacific Ocean. A comparison between CALIOP observations and ERA-Interim reanalysis data indicates that during their long-range transport over the tropical Pacific Ocean, these aerosols are slowly transported toward the marine boundary layer by the large-scale subsidence at a rate of 0.4 cm s(-1). The observed vertical/horizontal transport ratio is 0.700.8 m km(-1) Continental aerosols linked to transport over the Andes can be traced on average over 4000 km away from the continent indicating an aerosol residence time of 809 days in the FT over the Pacific Ocean. The FT aerosol optical depth (AOD) above the Pacific Ocean near South American coast accounts on average for 6% and 25% of the total AOD during the season of low and high biomass burning, respectively. This result shows that, during the biomass burning season, continental aerosols largely influence the AOD over the remote southeast Pacific Ocean. Overall, FT AOD decrease exponentially with the distance to continental sources at a rate of about 10% per degree of longitude over the Pacific Ocean.

  • 91.
    Bourgeois, Quentin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Ekman, Annica M. L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Renard, Jean-Baptiste
    Krejci, Radovan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Devasthale, Abhay
    Bender, Frida A. -M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Riipinen, Ilona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Berthet, Gwenaël
    Tackett, Jason L.
    How much of the global aerosol optical depth is found in the boundary layer and free troposphere?2018Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 18, nr 10, s. 7709-7720Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The global aerosol extinction from the CALIOP space lidar was used to compute aerosol optical depth (AOD) over a 9-year period (2007-2015) and partitioned between the boundary layer (BL) and the free troposphere (FT) using BL heights obtained from the ERA-Interim archive. The results show that the vertical distribution of AOD does not follow the diurnal cycle of the BL but remains similar between day and night highlighting the presence of a residual layer during night. The BL and FT contribute 69 and 31 %, respectively, to the global tropospheric AOD during daytime in line with observations obtained in Aire sur l'Adour (France) using the Light Optical Aerosol Counter (LOAC) instrument. The FT AOD contribution is larger in the tropics than at mid-latitudes which indicates that convective transport largely controls the vertical profile of aerosols. Over oceans, the FT AOD contribution is mainly governed by long-range transport of aerosols from emission sources located within neighboring continents. According to the CALIOP aerosol classification, dust and smoke particles are the main aerosol types transported into the FT. Overall, the study shows that the fraction of AOD in the FT - and thus potentially located above low-level clouds - is substantial and deserves more attention when evaluating the radiative effect of aerosols in climate models. More generally, the results have implications for processes determining the overall budgets, sources, sinks and transport of aerosol particles and their description in atmospheric models.

  • 92. Boy, Michael
    et al.
    Thomson, Erik S.
    Acosta Navarro, Juan-C.
    Arnalds, Olafur
    Batchvarova, Ekaterina
    Back, Jaana
    Berninger, Frank
    Bilde, Merete
    Brasseur, Zoe
    Dagsson-Waldhauserova, Pavla
    Castarede, Dimitri
    Dalirian, Maryam
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    de Leeuw, Gerrit
    Dragosics, Monika
    Duplissy, Ella-Maria
    Duplissy, Jonathan
    Ekman, Annica M. L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Fang, Keyan
    Gallet, Jean-Charles
    Glasius, Marianne
    Gryning, Sven-Erik
    Grythe, Henrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. NILU–Norwegian Institute for Air Research, Norway.
    Hansson, Hans-Christen
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Hansson, Margareta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Isaksson, Elisabeth
    Iversen, Trond
    Jonsdottir, Ingibjorg
    Kasurinen, Ville
    Kirkevag, Alf
    Korhola, Atte
    Krejci, Radovan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Kristjansson, Jon Egill
    Lappalainen, Hanna K.
    Lauri, Antti
    Lepparanta, Matti
    Lihavainen, Heikki
    Makkonen, Risto
    Massling, Andreas
    Meinander, Outi
    Nilsson, E. Douglas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Olafsson, Haraldur
    Pettersson, Jan B. C.
    Prisle, Nonne L.
    Riipinen, Ilona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Roldin, Pontus
    Ruppel, Meri
    Salter, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Sand, Maria
    Seland, Oyvind
    Seppa, Heikki
    Skov, Henrik
    Soares, Joana
    Stohl, Andreas
    Ström, Johan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Svensson, Jonas
    Swietlicki, Erik
    Tabakova, Ksenia
    Thorsteinsson, Throstur
    Virkkula, Aki
    Weyhenmeyer, Gesa A.
    Wu, Yusheng
    Zieger, Paul
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Kulmala, Markku
    Interactions between the atmosphere, cryosphere, and ecosystems at northern high latitudes2019Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 19, nr 3, s. 2015-2061Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Nordic Centre of Excellence CRAICC (Cryosphere-Atmosphere Interactions in a Changing Arctic Climate), funded by NordForsk in the years 2011-2016, is the largest joint Nordic research and innovation initiative to date, aiming to strengthen research and innovation regarding climate change issues in the Nordic region. CRAICC gathered more than 100 scientists from all Nordic countries in a virtual centre with the objectives of identifying and quantifying the major processes controlling Arctic warming and related feedback mechanisms, outlining strategies to mitigate Arctic warming, and developing Nordic Earth system modelling with a focus on short-lived climate forcers (SLCFs), including natural and anthropogenic aerosols. The outcome of CRAICC is reflected in more than 150 peer-reviewed scientific publications, most of which are in the CRAICC special issue of the journal Atmospheric Chemistry and Physics. This paper presents an overview of the main scientific topics investigated in the centre and provides the reader with a state-of-the-art comprehensive summary of what has been achieved in CRAICC with links to the particular publications for further detail. Faced with a vast amount of scientific discovery, we do not claim to completely summarize the results from CRAICC within this paper, but rather concentrate here on the main results which are related to feedback loops in climate change-cryosphere interactions that affect Arctic amplification.

  • 93. Brack, Werner
    et al.
    Ait-Aissa, Selim
    Backhaus, Thomas
    Birk, Sebastian
    Barcelo, Damia
    Burgess, Rob
    Cousins, Ian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Dulio, Valeria
    Escher, Beate I.
    Focks, Andreas
    van Gils, Jos
    Ginebreda, Antoni
    Hering, Daniel
    Hewitt, L. Mark
    Hilscherova, Klara
    Hollender, Juliane
    Hollert, Henner
    Kock, Marianne
    Kortenkamp, Andreas
    Lopez de Alda, Miren
    Mueller, Christin
    Posthuma, Leo
    Schueuermann, Gerrit
    Schymanski, Emma
    Segner, Helmut
    Sleeuwaert, Frank
    Slobodnik, Jaroslav
    Teodorovic, Ivana
    Umbuzeiro, Gisela
    Voulvoulis, Nick
    van Wezel, Annemarie
    Altenburger, Rolf
    Strengthen the European collaborative environmental research to meet European policy goals for achieving a sustainable, non-toxic environment2019Ingår i: Environmental Sciences Europe, ISSN 2190-4707, E-ISSN 2190-4715, Vol. 31, nr 1, artikel-id 63Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To meet the United Nations (UN) sustainable development goals and the European Union (EU) strategy for a non-toxic environment, water resources and ecosystems management require cost-efficient solutions for prevailing complex contamination and multiple stressor exposures. For the protection of water resources under global change conditions, specific research needs for prediction, monitoring, assessment and abatement of multiple stressors emerge with respect to maintaining human needs, biodiversity, and ecosystem services. Collaborative European research seems an ideal instrument to mobilize the required transdisciplinary scientific support and tackle the large-scale dimension and develop options required for implementation of European policies. Calls for research on minimizing society's chemical footprints in the water-food-energy-security nexus are required. European research should be complemented with targeted national scientific funding to address specific transformation pathways and support the evaluation, demonstration and implementation of novel approaches on regional scales. The foreseeable pressure developments due to demographic, economic and climate changes require solution-oriented thinking, focusing on the assessment of sustainable abatement options and transformation pathways rather than on status evaluation. Stakeholder involvement is a key success factor in collaborative projects as it allows capturing added value, to address other levels of complexity, and find smarter solutions by synthesizing scientific evidence, integrating governance issues, and addressing transition pathways. This increases the chances of closing the value chain by implementing novel solutions. For the water quality topic, the interacting European collaborative projects SOLUTIONS, MARS and GLOBAQUA and the NORMAN network provide best practice examples for successful applied collaborative research including multi-stakeholder involvement. They provided innovative conceptual, modelling and instrumental options for future monitoring and management of chemical mixtures and multiple stressors in European water resources. Advancement of EU water framework directive-related policies has therefore become an option.

  • 94. Brack, Werner
    et al.
    Dulio, Valeria
    Ågerstrand, Marlene
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Allan, Ian
    Altenburger, Rolf
    Brinkmann, Markus
    Bunke, Dirk
    Burgess, Robert M.
    Cousins, Ian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Escher, Beate I.
    Hernandez, Felix J.
    Hewitt, L. Mark
    Hilscherova, Klara
    Hollender, Juliane
    Hollert, Henner
    Kase, Robert
    Klauer, Bernd
    Lindim, Claudia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    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 resources2017Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 576, s. 720-737Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 95.
    Bradshaw, Clare
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Södertörn University College, Sweden.
    Strid, Anna
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    von Stedingk, Hans
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Gustafsson, Kerstin
    Effects of benthos, temperature, and dose on the fate of hexabromocyclododecane in experimental coastal ecosystems2015Ingår i: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 34, nr 6, s. 1246-1257Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The authors studied the fate of the brominated flame retardant hexabromocyclododecane (HBCDD) added in a particulate suspension to experimental ecosystems assembled from brackish (Baltic Sea) coastal bays. Two experiments examined how benthic macrofauna (over 21 d) and increased temperature (14 d) affected HBCDD concentrations and fractionation of , , and diastereomers in the water, sediment, and biota. A third experiment run over 3 seasons (231 d), studied the effect of HBCDD dose on the same endpoints. In all treatments of the 3 experiments, HBCDD partitioned mainly to the sediment, and this proportion increased with time. Presence of macrofauna tended to increase the HBCDD concentration in the sediment and decreased its concentration in the water. Increased temperature (+5 degrees C) decreased the amount of HBCDD in sediment and water but not in the filter- and deposit-feeding infaunal bivalves (Macoma balthica). The partitioning between water, sediment, and biota was not concentration dependent. In all treatments, sediment became enriched in -HBCDD, M. balthica in -HBCDD, and water in - and -HBCDD. Bioaccumulation of HBCDD in M. balthica was high in all experiments (log biota-sediment accumulation factor [BSAF] > 1.25), the diastereomer contributing the most (log BSAF 2.1-5.2). There is a risk of trophic transfer of HBCDD from benthic to pelagic food webs, as well as secondary poisoning of marine consumers. Environ Toxicol Chem 2015;34:1246-1257.

  • 96. Brits, Martin
    et al.
    Brandsma, Sicco H.
    Rohwer, Egmont R.
    De Vos, Jayne
    Weiss, Jana M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    de Boer, Jacob
    Brominated and organophosphorus flame retardants in South African indoor dust and cat hair2019Ingår i: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 253, s. 120-129Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Flame retardants (FRs), such as brominated flame retardants (BFRs) and organophosphorus flame retardants (OPFRs), are diverse groups of compounds used in various products related to the indoor environment. In this study concentrations of eight polybrominated diphenyl ethers (PBDEs), two alternative BFR5 and ten OPFRs were determined in indoor dust (n = 20) and pet cat hair (n = 11) from South Africa. The OPFRs were the major FRs, contributing to more than 97% of the total FR concentration. The median Sigma(10)OPFRs concentrations were 44,800 ng/g in freshly collected dust (F-dust), 19,800 ng/g in the dust collected from vacuum cleaner bags (V-dust), and 865 ng/g in cat hair (C-hair). Tris(1-chloro-2-propyl) phosphate (TCIPP) was the dominant OPFR in the dust samples with median concentrations of 7,010 ng/g in F-dust and 3,590 ng/g in V-dust. Tris(2-butoxyethyl) phosphate (TBOEP) was the dominant OPFR in C-hair, with a median concentration of 387 ng/g. The concentrations of Sigma 8PBDEs were higher in F-dust than in V-dust. BDE209 was the dominant BFR in all three matrices. Bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5- tetrabromobenzoate (EH-TBB) showed notable contributions to the BFR profile in cat hair. A worst-case dust exposure estimation was performed for all analytes. The estimated TCIPP daily intake through dust ingestion was up to 1,240 ng/kg bw for toddlers. The results indicate that OPFRs are ubiquitous in South African indoor environment. Indoor dust is a major source of human exposure to environmental contaminants. This can for example occur through hand-to-mouth contact of toddlers, and is an important route of exposure to currently used FRs accumulated on dust particles. The presence of FRs, in particular high concentrations of OPFRs, suggests that children and indoor pet cats may have greater exposure to FRs than adults.

  • 97. Brits, Martin
    et al.
    de Vos, Jayne
    Weiss, Jana M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Rohwer, Egmont R.
    de Boer, Jacob
    Critical review of the analysis of brominated flame retardants and their environmental levels in Africa2016Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 164, s. 174-189Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    World-wide, the prevalence of brominated flame retardants (BFRs) is well documented for routine analysis of environmental and biological matrices. There is, however, limited information on these compounds in the African environment and insufficient information on the analytical approaches used to obtain data. This paper presents a review on BFR levels in the African environment and the various analytical methodologies specifically applied in Africa for polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls and alternative-BFRs. The analyses include liquid sample preparation using liquid-liquid and solid phase extraction and solid sample preparation involving Soxhlet extraction, with ultrasound-assisted extraction increasingly being applied. Instrumental detection techniques were limited to gas chromatography coupled with electron capture detector and electron impact ionisation with single quadrupole mass spectrometers. Information on congener profile prevalence in indoor dust, soil, aquatic environment (water, sediment, and aquatic organisms), eggs, wastewater treatment plant compartments, landfills (leachate and sediment) and breast milk are presented. Although PBDEs were inconsistently detected, contamination was reported for all investigated matrices in the African environment. The manifestation in remote regions indicates the ubiquitous prevalence and long-range transport of these compounds. Levels in sediment, and breast milk from some African countries were higher than reported for Asia and Europe. Due to limited data or non-detection of alternative-BFRs, it is unclear whether banned formulations were replaced in Africa. Most of the data reported for BFR levels in Africa were obtained in non-African laboratories or in South Africa and formed the basis for our discussion of reported contamination levels and related methodologies.

  • 98. Brits, Martin
    et al.
    Gorst-Allman, Peter
    Rohwer, Egmont R.
    De Vos, Jayne
    de Boer, Jacob
    Weiss, Jana M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Swedish University of Agricultural Sciences, Sweden.
    Comprehensive two-dimensional gas chromatography coupled to high resolution time-of-flight mass spectrometry for screening of organohalogenated compounds in cat hair2018Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1536, s. 151-162Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The coupling of comprehensive two-dimensional gas chromatography with high-resolution time of-flight mass spectrometry offers the best separation efficiency combined with accurate mass measurements over a wide mass range. The tremendous power of this screening tool is illustrated by trace qualitative screening analysis of organohalogenated compounds (OHCs) in pet cat hair. Tentative identification was supported by mass spectral database searches and elemental formula prediction from the experimentally determined accurate mass data. This screening approach resulted in the first tentative identification of pentabromoethylbenzene, decabromodiphenyl ethane, hexabromocyclododecane, trisbromoneopentyl alcohol, tris(2-chloroethyl) phosphate and tris(2-chloroisopropyl)phosphate in the South African indoor environment. A total of seventy-two OHCs were identified in the samples and include known flame retardants, such as polybrominated diphenyl ethers, and legacy contaminants such as polychlorinated biphenyls and organochlorine, organophosphorous and pyrethroid pesticides. The results obtained from cat hair indicate that these pets are exposed to complex mixtures of OHCs and the detection of these compounds suggests that non-invasive cat hair samples can be used to model indoor exposure with reference to external deposition of OHCs present in the air and dust surrounding people. Toddlers share the same environment as pet cats and therefore also the same health risks.

  • 99. Brus, David
    et al.
    Skrabalova, Lenka
    Herrmann, Erik
    Olenius, Tinja
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. University of Helsinki, Finland.
    Travnickova, Tereza
    Makkonen, Ulla
    Merikanto, Joonas
    Temperature-Dependent Diffusion of H2SO4 in Air at Atmospherically Relevant Conditions: Laboratory Measurements Using Laminar Flow Technique2017Ingår i: Atmosphere, ISSN 2073-4433, E-ISSN 2073-4433, Vol. 8, nr 7, artikel-id 132Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report flow tube measurements of the effective sulfuric acid diffusion coefficient at ranges of different relative humidities (from similar to 4 to 70%), temperatures (278, 288 and 298 K) and initial H2SO4 concentrations (from 1 x 10(6) to 1 x 10(8) molecules.cm(-3)). The measurements were carried out under laminar flow of humidified air containing trace amounts of impurities such as amines (few ppt), thus representing typical conditions met in Earth's continental boundary layer. The diffusion coefficients were calculated from the sulfuric acid wall loss rate coefficients that were obtained by measuring H2SO4 concentration continuously at seven different positions along the flow tube with a chemical ionization mass spectrometer (CIMS). The wall loss rate coefficients and laminar flow conditions were verified with additional computational fluid dynamics (CFD) model FLUENT simulations. The determined effective sulfuric acid diffusion coefficients decreased with increasing relative humidity, as also seen in previous experiments, and had a rather strong power dependence with respect to temperature, around proportional to T-5.6, which is in disagreement with the expected temperature dependence of similar to T-1.75 for pure vapours. Further clustering kinetics simulations using quantum chemical data showed that the effective diffusion coefficient is lowered by the increased diffusion volume of H2SO4 molecules via a temperature-dependent attachment of base impurities like amines. Thus, the measurements and simulations suggest that in the atmosphere the attachment of sulfuric acid molecules with base molecules can lead to a lower than expected effective sulfuric acid diffusion coefficient with a higher than expected temperature dependence.

  • 100.
    Bröder, Lisa
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Vrije Universiteit Amsterdam, Netherlands.
    Andersson, August
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Tesi, Tommaso
    Semiletov, Igor
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Quantifying Degradative Loss of Terrigenous Organic Carbon in Surface Sediments Across the Laptev and East Siberian Sea2019Ingår i: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 33, nr 1, s. 85-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ongoing permafrost thaw in the Arctic may remobilize large amounts of old organic matter. Upon transport to the Siberian shelf seas, this material may be degraded and released to the atmosphere, exported off-shelf, or buried in the sediments. While our understanding of the fate of permafrost-derived organic matter in shelf waters is improving, poor constraints remain regarding degradation in sediments. Here we use an extensive data set of organic carbon concentrations and isotopes (n=109) to inventory terrigenous organic carbon (terrOC) in surficial sediments of the Laptev and East Siberian Seas (LS + ESS). Of these similar to 2.7 Tg terrOC about 55% appear resistant to degradation on a millennial timescale. A first-order degradation rate constant of 1.5 kyr(-1) is derived by combining a previously established relationship between water depth and cross-shelf sediment-terrOC transport time with mineral-associated terrOC loadings. This yields a terrOC degradation flux of similar to 1.7Gg/year from surficial sediments during cross-shelf transport, which is orders of magnitude lower than earlier estimates for degradation fluxes of dissolved and particulate terrOC in the water column of the LS + ESS. The difference is mainly due to the low degradation rate constant of sedimentary terrOC, likely caused by a combination of factors: (i) the lower availability of oxygen in the sediments compared to fully oxygenated waters, (ii) the stabilizing role of terrOC-mineral associations, and (iii) the higher proportion of material that is intrinsically recalcitrant due to its chemical/molecular structure in sediments. Sequestration of permafrost-released terrOC in shelf sediments may thereby attenuate the otherwise expected permafrost carbon-climate feedback. Plain language summary Frozen soils in the Arctic contain large amounts of old organic matter. With ongoing climate change this previously freeze-locked carbon storage becomes vulnerable to transport and decay. Upon delivery to the shallow nearshore seas, it may either be directly degraded to carbon dioxide or methane and thereby fuel further warming or get buried and stored in sediments on the sea floor. Our understanding of the fate of carbon released from permafrost soils is increasing, yet uncertainties remain regarding its degradation in the sediment. Here we constrain how much land-derived organic carbon is deposited in the top layer of the sediment (the part that is prone to transport and exposed to oxygen-stimulated degradation) in the Laptev and East Siberian Seas. We find that more than half of this stock likely resists degradation, while the rest decays relatively slowly. Therefore, the amount of carbon released annually from degradation in surface sediments is much smaller than what was found to be emitted from overlying waters in earlier studies. We suspect that this difference is caused by a combination of mechanisms hindering degradation in sediments and thus conclude that the burial of land-derived carbon may help to dampen the climate impact of thawing permafrost.

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