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  • 1.
    Adolfsson-Erici, Margaretha
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Åkerman, Gun
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Internal Benchmarking Improves Precision and Reduces Animal Requirements for Determination of Fish Bioconcentration Factors2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 15, p. 8205-8211Article in journal (Refereed)
    Abstract [en]

    The enactment of new chemical regulations has generated a large need for the measurement of the fish bioconcentration factor (BCF). Past experience shows that the BCF determination lacks precision, requires large numbers of fish, and is costly. A new protocol was tested that shortens the experiment from up to 12 weeks for existing protocols to 2 weeks and reduces the number of fish by a factor of 5, while introducing internal benchmarking for the BCF determination. Rainbow trout were simultaneously exposed to 11 chemicals. The BCFs were quantified using one of the test chemicals, musk xylene, as a benchmark. These were compared with BCFs measured in a parallel experiment based on the OECD 305 guideline. The agreement was <20% for five chemicals and between 20%-25% for two further, while two chemicals lay outside the BCF operating window of the experiment and one was lost due to analytical difficulties. This agreement is better than that observed in a BCF Gold Standard Database. Internal benchmarking allows the improvement of the precision of BCF determination in parallel to large reduction in costs and fish requirements.

  • 2.
    Aeppli, Christoph
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bastviken, David
    Andersson, Per
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Chlorine Isotope Effects and Composition of Naturally Produced Organochlorines from Chloroperoxidases, Flavin-Dependent Halogenases, and in Forest Soil2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 13, p. 6864-6871Article in journal (Refereed)
    Abstract [en]

    The use of stable chlorine isotopic signatures (delta Cl-37) of organochlorine compounds has been suggested as a tool to determine both their origins and transformations in the environment. Here we investigated the delta Cl-37 fractionation of two important pathways for enzymatic natural halogenation: chlorination by chloroperoxidase (CPO) and flavin-dependent halogenases (FDH). Phenolic products of CPO were highly Cl-37 depleted (delta Cl-37 = -12.6 +/- 0.9 parts per thousand); significantly more depleted than all known industrially produced organochlorine compounds (delta Cl-37 = -7 to +6 parts per thousand). In contrast, four FDH products did not exhibit any observable isotopic shifts (delta Cl-37 = -0.3 +/- 0.6 parts per thousand). We attributed the different isotopic effect to the distinctly different chlorination mechanisms employed by the two enzymes. Furthermore, the delta Cl-37 in bulk organochlorines extracted from boreal forest soils were only slightly depleted in Cl-37 relative to inorganic Cl. In contrast to previous suggestions that CPO plays a key role in production of soil organochlorines, this observation points to the additional involvement of either other chlorination pathways, or that dechlorination of naturally produced organochlorines can neutralize delta Cl-37 shifts caused by CPO chlorination. Overall, this study demonstrates that chlorine isotopic signatures are highly useful to understand sources and cycling of organochlorines in nature. Furthermore, this study presents delta Cl-37 values of FDH products as well of bulk organochlorines extracted from pristine forest soil for the first time.

  • 3.
    Aeppli, Christoph
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Tysklind, Mats
    Holmstrand, Henry
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Use of Cl and C Isotopic Fractionation to Identify Degradation and Sources of Polychlorinated Phenols: Mechanistic Study and Field Application2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 2, p. 790-797Article in journal (Refereed)
    Abstract [en]

    The widespread use of chlorinated phenols (CPs) as a wood preservative has led to numerous contaminated sawmill sites. However, it remains challenging to assess the extent of in situ degradation of CPs. We evaluated the use of compound-specific chlorine and carbon isotope analysis (Cl- and C-CSLA) to assess CP biotransformation. In a laboratory system, we measured isotopic fractionation during oxidative 2,4,6-trichlorophenol dechlorination by representative soil enzymes (C. fumago chloroperoxidase, horseradish peroxidase, and laccase from T. versicolor). Using a mathematical model, the validity of the Rayleigh approach to evaluate apparent kinetic isotope effects (AKIE) was confirmed. A small but significant Cl-AKIE of 1.0022 +/- 0.0006 was observed for all three enzymes, consistent with a reaction pathway via a cationic radical species. For carbon, a slight inverse isotope effect was observed (C-AKIE = 0.9945 +/- 0.0019). This fractionation behavior is clearly distinguishable from reported reductive dechlorination mechanisms. Based on these results we then assessed degradation and apportioned different types of technical CP mixtures used at two former sawmill sites. To our knowledge, this is the first study that makes use of two-element CSIA to study sources and transformation of CPs in the environment.

  • 4. Alves, Andreia
    et al.
    Giovanoulis, Georgios
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Environmental Research Institute, Sweden.
    Nilsson, Ulrika
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Erratico, Claudio
    Lucattini, Luisa
    Haug, Line S.
    Jacobs, Griet
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Leonards, Pim E. G.
    Covaci, Adrian
    Magner, Jorgen
    Voorspoels, Stefan
    Case Study on Screening Emerging Pollutants in Urine and Nails2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 7, p. 4046-4053Article in journal (Refereed)
    Abstract [en]

    Alternative plasticizers and flame retardants (FRs) have been introduced as replacements for banned or restricted chemicals, but much is still unknown about their metabolism and occurrence in humans. We identified the metabolites formed in vitro for four alternative plasticizers (acetyltributyl citrate (ATBC), bis(2-propylheptyl) phthalate (DPHP), bis(2-ethylhexyl) terephthalate (DEHTP), bis(2ethylhexyl) adipate (DEHA)), and one FR (2,2-bis (chloromethyl)-propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate (V6)). Further, these compounds and their metabolites were investigated by LC/ESI-Orbitrap-MS in urine and finger nails collected from a Norwegian cohort. Primary and secondary ATBC metabolites had detection frequencies (% DF) in finger nails ranging from 46 to 95%. V6 was identified for the first time in finger nails, suggesting that this matrix may also indicate past exposure to FRs as well as alternative plasticizers. Two isomeric forms of DEHTP primary metabolite were highly detected in urine (97% DF) and identified in finger nails, while no DPHP metabolites were detected in vivo. Primary and secondary DEHA metabolites were identified in both matrices, and the relative proportion of the secondary metabolites was higher in urine than in finger nails; the opposite was observed for the primary metabolites. As many of the metabolites present in in vitro extracts were further identified in vivo in urine and finger nail samples, this suggests that in vitro assays can reliably mimic the in vivo processes. Finger nails may be a useful noninvasive matrix for human biomonitoring of specific organic contaminants, but further validation is needed.

  • 5.
    Andersson, August
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Deng, Junjun
    Du, Ke
    Zheng, Mei
    Yan, Caiqing
    Sköld, Martin
    Stockholm University, Faculty of Science, Department of Mathematics.
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Regionally-Varying Combustion Sources of the January 2013 Severe Haze Events over Eastern China2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 4, p. 2038-2043Article in journal (Refereed)
    Abstract [en]

    Thick haze plagued northeastern China in January 2013, strongly affecting both regional climate and human respiratory health. Here, we present dual carbon isotope constrained (Delta C-14 and delta C-13) source apportionment for combustion-derived black carbon aerosol (BC) for three key hotspot regions (megacities): North China Plain (NCP, Beijing), the Yangtze River Delta (YRD, Shanghai), and the Pearl River Delta (PRD, Guangzhou) for January 2013. BC, here quantified as elemental carbon (EC), is one of the most health-detrimental components of PM2.5 and a strong climate warming agent. The results show that these severe haze events were equally affected (similar to 30%) by biomass combustion in all three regions, whereas the sources of the dominant fossil fuel component was dramatically different between north and south. In the NCP region, coal combustion accounted for 66% (46-74%, 95% C.I.) of the EC, whereas, in the YRD and PRD regions, liquid fossil fuel combustion (e.g., traffic) stood for 46% (18-66%) and 58% (38-68%), respectively. Taken together, these findings suggest the need for a regionally-specific description of BC sources in climate models and regionally-tailored mitigation to combat severe air pollution events in East Asia.

  • 6.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Macleod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Comparative Assessment of the Global Fate and Transport Pathways of Long-chain Perfluorocarboxylic Acids (PFCAs) and Perfluorocarboxylates (PFCs) Emitted from Direct Sources2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 15, p. 5830-5836Article in journal (Refereed)
    Abstract [en]

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

  • 7.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    McLachlan, Michael
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modeling the Global Fate and Transport of Perfluorooctanoic Acid (PFOA) and Perfluorooctanoate (PFO) Emitted from Direct Sources Using a Multispecies Mass Balance Model2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 4, p. 1134-1140Article in journal (Refereed)
    Abstract [en]

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

  • 8.
    Armitage, James M
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Schenker, Urs
    Scheringer, Martin
    Martin, Jonathan W
    Macleod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modeling the Global Fate and Transport of Perfluorooctane Sulfonate (PFOS) and Precursor Compounds in Relation to Temporal Trends in Wildlife Exposure.2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 24, p. 9274-80Article in journal (Refereed)
    Abstract [en]

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

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

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

  • 10. Arp, Hans Peter H.
    et al.
    Azzolina, Nicholas A.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hawthorne, Steven B.
    Predicting Pore Water EPA-34 PAH Concentrations and Toxicity in Pyrogenic-Impacted Sediments Using Pyrene Content2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 12, p. 5139-5146Article in journal (Refereed)
    Abstract [en]

    Sediment and freely dissolved pore water concentrations of the U.S. Environmental Protection Agency's list of 34 alkyl and parent PAHs (EPA-34) were measured in 335 sediment samples from 19 different sites impacted by manufactured gas plants, aluminum smelters and other pyrogenic sources. The total EPA-34 freely dissolved pore water concentration, C(pw,EPA-34), expressed as toxic units (TU) is currently considered one of the most accurate measures to assess risk at such sites; however, it is very seldom measured. With this data set, we address how accurately C(pw,EPA-34) can be estimated using limited 16 parent PAH data (EPA-16) commonly available for such sites. An exhaustive statistical analysis of the obtained data validated earlier observations that PAHs with more than 3 rings are present in similar relative abundances and their partitioning behavior typically follows Raoult's law and models developed for coal tar. As a result, sediment and freely dissolved pore water concentrations of pyrene and other 3- and 4-ring PAT-Is exhibit good log log correlations (r(2) > 0.8) to most individual EPA-34 PAHs and also to C(pw,EPA,34). Correlations improve further by including the ratio of high to low molecular weight PAHs, as 2-ring PAT-Is exhibit the most variability in terms of their relative abundance. The most practical result of the current work is that log Cpw,EPA-34 estimated by the recommended pyrene-based estimation techniques was similarly well correlated to % survival of the benthic amphipods Hyalella azteca and Leptocheirus plumulosus as directly measured log Cpw, (EPA-34) values (n = 211). Incorporation of the presented C(pw,EPA-34) estimation techniques could substantially improve risk assessments and guidelines for sediments impacted by pyrogenic residues, especially when limited data are available, without requiring any extra data or measurement costs.

  • 11. Arp, Hans Peter H.
    et al.
    Kühnel, Dana
    Rummel, Christoph
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Potthoff, Annegret
    Reichelt, Sophia
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Rojo-Nieto, Elisa
    Schmitt-Jansen, Mechthild
    Sonnenberg, Johanna
    Toorman, Erik
    Jahnke, Annika
    Weathering Plastics as a Planetary Boundary Threat: Exposure, Fate, and Hazards2021In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 55, no 11, p. 7246-7255Article in journal (Refereed)
    Abstract [en]

    We described in 2017 how weathering plastic litter in the marine environment fulfils two of three criteria to impose a planetary boundary threat related to chemical pollution and the release of novel entities: (1) planetary-scale exposure, which (2) is not readily reversible. Whether marine plastics meet the third criterion, (3) eliciting a disruptive impact on vital earth system processes, was uncertain. Since then, several important discoveries have been made to motivate a re-evaluation. A key issue is if weathering macroplastics, microplastics, nanoplastics, and their leachates have an inherently higher potential to elicit adverse effects than natural particles of the same size. We summarize novel findings related to weathering plastic in the context of the planetary boundary threat criteria that demonstrate (1) increasing exposure, (2) fate processes leading to poorly reversible pollution, and (3) (eco)toxicological hazards and their thresholds. We provide evidence that the third criterion could be fulfilled for weathering plastics in sensitive environments and therefore conclude that weathering plastics pose a planetary boundary threat. We suggest future research priorities to better understand (eco)toxicological hazards modulated by increasing exposure and continuous weathering processes, to better parametrize the planetary boundary threshold for plastic pollution.

  • 12. Arp, Hans Peter H.
    et al.
    Lundstedt, Staffan
    Josefsson, Sarah
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Enell, Anja
    Allard, Ann-Sofie
    Kleja, Dan Berggren
    Native Oxy-PAHs, N-PACs, and PAHs in Historically Contaminated Soils from Sweden, Belgium, and France: Their Soil-Porewater Partitioning Behavior, Bioaccumulation in Enchytraeus crypticus, and Bioavailability2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 19, p. 11187-11195Article in journal (Refereed)
    Abstract [en]

    Soil quality standards are based on partitioning and toxicity data for laboratory-spiked reference soils, instead of real world, historically contaminated soils, which would be more representative. Here 21 diverse historically contaminated soils from Sweden, Belgium, and France were obtained, and the soil-porewater partitioning along with the bioaccumulation in exposed worms (Enchytraeus crypticus) of native polycyclic aromatic compounds (PACs) were quantified. The native PACs investigated were polycyclic aromatic hydrocarbons (PAHs) and, for the first time to be included in such a study, oxygenated-PAHs (oxy-PAHs) and nitrogen containing heterocyclic PACs (N-PACs). The passive sampler polyoxymethylene (POM) was used to measure the equilibrium freely dissolved porewater concentration, C-pw, of all PACs. The obtained organic carbon normalized partitioning coefficients, K-TOC, show that sorption of these native PACs is much stronger than observed in laboratory-spiked soils (typically by factors 10 to 100), which has been reported previously for PAHs but here for the first time for oxy-PAHs and N-PACs. A recently developed K-TOC model for historically contaminated sediments predicted the 597 unique, native K-TOC values in this study within a factor 30 for 100% of the data and a factor 3 for 58% of the data, without calibration. This model assumes that TOC in pyrogenic-impacted areas sorbs similarly to coal tar, rather than octanol as typically assumed. Black carbon (BC) inclusive partitioning models exhibited substantially poorer performance. Regarding bioaccumulation, C-pw combined with liposome-water partition coefficients corresponded better with measured worm lipid concentrations, C-lipid (within a factor 10 for 85% of all PACs and soils), than C-pw combined with octanol-water partition coefficients (within a factor 10 for 76% of all PACs and soils). E. crypticus mortality and reproducibility were also quantified. No enhanced mortality was observed in the 21 historically contaminated soils despite expectations from PAH spiked reference soils. Worm reproducibility weakly correlated to C-lipid of PACs, though the contributing influence of metal concentrations and soil texture could not be taken into account. The good agreement of POM-derived C-pw with independent soil and lipid partitioning models further supports that soil risk assessments would improve by accounting for bioavailability. Strategies for including bioavailability in soil risk assessment are presented.

  • 13. Arp, H.P.H.
    et al.
    Breedveld, G.D.
    Cornelissen, Gerard
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Estimating the in situ Sediment-Porewater Distribution of PAHs and Chlorinated Aromatic Hydrocarbons in Anthropogenic Impacted Sediments2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 15, p. 5576-5585Article in journal (Refereed)
    Abstract [en]

    It has become increasingly apparent that the in situ sediment-porewater distribution behavior of organic compounds within anthropogenic impacted sediments is quite diverse, and challenging to generalize. Traditional models based on octanol-water partitioning generally overestimate native porewater concentrations, and modern approaches accounting for multiple carbon fractions, including black carbon, appear sediment specific. To assess the diversity of this sorption behavior, we collected all peer-reviewed total organic carbon (TOC)-normalized in situ sediment-porewater distribution coefficients, K-TOC, for impacted sediments. This entailed several hundreds of data for PAHs, PCBs, PCDO/Fs, and chlorinated benzenes, covering a large variety of sediments, locations, and experimental methods. Compound-specific K-TOC could range up to over 3 orders of magnitude. Output from various predictive models for individual carbonaceous phases found in impacted sediments, based on peer-reviewed polyparameter linear free energy relationships (PP-LFERs), Raoult's Law, and the SPARC online-calculator, were tested to see if any of the models could consistently predict literature K-TOC values within a factor of 30 (i.e., similar to 1.5 orders of magnitude, or half the range of K-TOC values), The Raoult's Law model and coal tar PP-LFER achieved the sought-after accuracy for all tested compound classes, and are recommended for general, regional-scale modeling purposes. As impacted sediment-porewater distribution models are unlikely to get more accurate than this, this review underpins that the only way to accurately obtain accurate porewater concentrations is to measure them directly, and not infer them from sediment concentrations

  • 14. Assefa, Anteneh T.
    et al.
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sundqvist, Kristina L.
    Cato, Ingemar
    Jonsson, Per
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Tysklind, Mats
    Wiberg, Karin
    Temporal Trends of PCDD/Fs in Baltic Sea Sediment Cores Covering the 20th Century2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 2, p. 947-953Article in journal (Refereed)
    Abstract [en]

    The pollution trend of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea region was studied based on depth profiles of PCDD/Fs in sediment cores collected from six-offshore areas, eight coastal sites impacted by industrial/urban emissions, and one coastal reference site. A general trend was observed for the offshore and coastal reference sites with substantial increase in PCDD/F concentrations in the mid-late 1970s and peak levels during 1985-2002. The overall peak year for PCDD/Fs in Baltic Sea offshore areas was estimated (using spline-fit modeling) to 1994 +/- 5 years, and a half-life in sediments was estimated at 29 +/- 11 years. For the industrial/urban impacted coastal sites, the temporal trend was more variable with peak years occurring 1-2 decades earlier compared to offshore areas. The substantial reductions from peak levels (38 +/- 11% and 81 +/- 12% in offshore and coastal areas, respectively) reflect domestic and international actions taken for reduction of the release of PCDD/Fs to the environment. The modeled overall half-life and reductions of PCDD/Fs in offshore Baltic Sea sediment correspond well to both PCDD/F trends in European lakes without any known direct. PCDD/F sources (half-lives 30 and 32 years), and previously modeled reduction in atmospheric deposition of,PCDD/Fs to the Baltic Sea since 1990. These observations support previous findings of a common diffuse source, such as long-range air transport of atmospheric emissions, as the prime source of PCDD/Fs to the Baltic Sea region. The half-life of PCDD/Fs in Baltic Sea offshore sediments was estimated to be approximately 2 and 4-6 times longer than in semirural and urban European air, respectively. This study highlights the need for further international actions to reduce the levels of PCDD/Fs in Baltic Sea air specifically and in European air in general.

  • 15. Assefa, Anteneh T.
    et al.
    Tysklind, Mats
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Sundqvist, Kristina L.
    Geladi, Paul
    Wiberg, Karin
    Assessment of PCDD/F Source Contributions in Baltic Sea Sediment Core Records2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 16, p. 9531-9539Article in journal (Refereed)
    Abstract [en]

    Spatial and temporal trends of sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea were evaluated by positive matrix factorization (PMF) and principal component analysis (PCA). Sediment cores were sampled at eight coastal, one coastal reference, and six offshore sites covering the northern to the southern Baltic Sea. The cores, which covered the period 1919-2010, were sliced into 2-3 cm disks among which 8-11 disks per core (in total 141 disks) were analyzed for all tetra- through octa-CDD/Fs. Identification and apportionment of PCDD/F sources was carried out using PMF. Five stable model PCDD/F congener patterns were identified, which could be associated with six historically important source types: (i) atmospheric background deposition (ABD), (ii) use and production of pentachlorophenol (PCP), (iii) use and production of tetra-chlorophenol (TeCP), (iv) high temperature processes (Thermal), (v) hexa-CDD-related sources (HxCDD), and (vi) chlorine-related sources (Chi), all of which were still represented in the surface layers. Overall, the last four decades of the period 1920-2010 have had a substantial influence on the Baltic Sea PCDD/F pollution, with 88 +/- 7% of the total amount accumulated during this time. The 1990s was the peak decade for all source types except TeCP, which peaked in the 1980s in the northern Baltic Sea and has still not peaked in the southern part. The combined impact of atmospheric-related emissions (ABD and Thermal) was dominant in the open sea system throughout the study period (1919-2010) and showed a decreasing south to north trend (always >80% in the south and >50% in the north). Accordingly, to further reduce levels of PCDD/Fs in the open Baltic Sea ecosystem, future actions should focus on reducing atmospheric emissions.

  • 16. Balouet, Jean Christophe
    et al.
    Burken, Joel G.
    Karg, Frank
    Vroblesky, Don
    Smith, Kevin T.
    Grudd, Håkan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Rindby, Anders
    Beaujard, Francois
    Chalot, Michel
    Dendrochemistry of Multiple Releases of Chlorinated Solvents at a Former Industrial Site2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 17, p. 9541-9547Article in journal (Refereed)
    Abstract [en]

    Trees can take up and assimilate contaminants from the soil, subsurface, and groundwater. Contaminants in the transpiration stream can become bound or incorporated into the annual rings formed in trees of the temperate zones. The chemical analysis of precisely dated tree rings, called dendrochemistry, can be used to interpret past plant interactions with contaminants. This investigation demonstrates that dendrochemistry can be used to generate historical scenarios of past contamination of groundwater by chlorinated solvents at a site in Verl, Germany. Increment cores from trees at the Verl site were collected and analyzed by energy-dispersive X-ray fluorescence (EDXRF) line scanning. The EDXRF profiles showed four to six time periods where tree rings had anomalously high concentrations of chlorine (Cl) as an indicator of potential contamination by chlorinated solvents.

  • 17. Bannan, Thomas J.
    et al.
    Booth, A. Murray
    Jones, Benjamin T.
    O'Meara, Simon
    Barley, Mark H.
    Riipinen, Ilona
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Percival, Carl J.
    Topping, David
    Measured Saturation Vapor Pressures of Phenolic and Nitro-aromatic Compounds2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 7, p. 3922-3928Article in journal (Refereed)
    Abstract [en]

    Phenolic and nitro-aromatic compounds are extremely toxic components of atmospheric aerosol that are currently not well understood. In this Article, solid and subcooled-liquid-state saturation vapor pressures of phenolic and nitro-aromatic compounds are measured using Knudsen Effusion Mass Spectrometry (KEMS) over a range of temperatures (298-318 K). Vapor pressure estimation methods, assessed in this study, do not replicate the observed dependency on the relative positions of functional groups. With a few exceptions, the estimates are biased toward predicting saturation vapor pressures that are too high, by 5-6 orders of magnitude in some cases. Basic partitioning theory comparisons indicate that overestimation of vapor pressures in such cases would cause us to expect these compounds to be present in the gas state, whereas measurements in this study suggest these phenolic and nitro-aromatic will partition into the condensed state for a wide range of ambient conditions if absorptive partitioning plays a dominant role. While these techniques might have both structural and parametric uncertainties, the new data presented here should support studies trying to ascertain the role of nitrogen containing organics on aerosol growth and human health impacts.

  • 18. Bastviken, David
    et al.
    Santoro, Ana Lucia
    Marotta, Humberto
    Pinho, Luana Queiroz
    Calheiros, Debora Fernandes
    Crill, Patrick
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Enrich-Prast, Alex
    Methane Emissions from Pantanal, South America, during the Low Water Season: Toward More Comprehensive Sampling2010In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 44, no 14, p. 5450-5455Article in journal (Refereed)
    Abstract [en]

    Freshwater environments contribute 75% of the natural global methane (CH4) emissions. While there are indications that tropical lakes and reservoirs emit 58-400% more CH4 per unit area than similar environments in boreal and temperate biomes, direct measurements of tropical lake emissions are scarce. We measured CH4 emissions from 16 natural shallow lakes in the Pantanal region of South America, one of the world's largest tropical wetland areas, during the low water period using floating flux chambers. Measured fluxes ranged from 3.9 to 74.2 mmol m(-2) d(-1) with the average from all studied lakes being 8.8 mmol m(-2) d(-1) (131.8 mg CH4 m(-2) d(-1)), of which ebullition accounted for 91% of the flux (28-98% on individual lakes). Diel cycling of emission rates was observed and therefore 24-h long measurements are recommended rather than short-term measurements not accounting for the full diel cycle. Methane emission variability within a lake may be equal to or more important than between lake variability in floodplain areas as this study identified diverse habitats within lakes having widely different flux rates. Future measurements with static floating chambers should be based on many individual chambers distributed in the various subenvironments of a lake that may differ in emissions in order to account for the within lake variability.

  • 19.
    Bastviken, David
    et al.
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Svensson, Teresia
    Karlsson, Susanne
    Sanden, Per
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Oberg, Gunilla
    Temperature Sensitivity Indicates That Chlorination of Organic Matter in Forest Soil Is Primarily Biotic2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 10, p. 3569-3573Article in journal (Refereed)
    Abstract [en]

    Old assumptions that chloride is inert and that most chlorinated organic matter in soils is anthropogenic have been challenged by findings of naturally formed organochlorines. Such natural chlorination has been recognized for several decades, but there are still very few measurements of chlorination rates or estimates of the quantitative importance of terrestrial chlorine transformations. While much is known about the formation of specific compounds, bulk chlorination remains poorly understood in terms of mechanisms and effects of environmental factors. We quantified bulk chlorination rates in coniferous forest soil using Cl-36-chloride in tracer experiments at different temperatures and with and without molecular oxygen (O-2). Chlorination was enhanced by the presence of O-2 and had a temperature optimum at 20 degrees C. Minimum rates were found at high temperatures (50 degrees C) or under anoxic conditions. The results indicate (1) that most of the chlorination between 4 and 40 degrees C was biotic and driven by O-2 dependent enzymes, and (2) that there is also slower background chlorination occurring under anoxic conditions at 20 degrees C and under oxic conditions at 50 degrees C. Hence, while oxic and biotic chlorination clearly dominated, chlorination by other processes including possible abiotic reactions was also detected.

  • 20. Beltran, Angelica Mendoza
    et al.
    Prado, Valentina
    Vivanco, David Font
    Henriksson, Patrik J. G.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. WorldFish, Jalan Batu Maung, Malaysia.
    Guinee, Jeroen B.
    Heijungs, Reinout
    Quantified Uncertainties in Comparative Life Cycle Assessment: What Can Be Concluded?2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 4, p. 2152-2161Article in journal (Refereed)
    Abstract [en]

    Interpretation of comparative Life Cycle Assessment (LCA) results can be challenging in the presence of uncertainty. To aid in interpreting such results under the goal of any comparative LCA, we aim to provide guidance to practitioners by gaining insights into uncertainty-statistics methods (USMs). We review five USMs-discernibility analysis, impact category relevance, overlap area of probability distributions, null hypothesis significance testing (NHST), and modified NHST- and provide a common notation, terminology, and calculation platform. We further cross-compare all USMs by applying them to a case study on electric cars. USMs belong to a confirmatory or an exploratory statistics' branch, each serving different purposes to practitioners. Results highlight that common uncertainties and the magnitude of differences per impact are key in offering reliable insights. Common uncertainties are particularly important as disregarding them can lead to incorrect recommendations. On the basis of these considerations, we recommend the modified NHST as a confirmatory USM. We also recommend discernibility analysis as an exploratory USM along with recommendations for its improvement, as it disregards the magnitude of the differences. While further research is necessary to support our conclusions, the results and supporting material provided can help LCA practitioners in delivering a more robust basis for decision-making.

  • 21. Bergman, Kristina
    et al.
    Henriksson, Patrik J. G.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Hornborg, Sara
    Troell, Max
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Borthwick, Louisa
    Jonell, Malin
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Philis, Gaspard
    Ziegler, Friederike
    Recirculating Aquaculture Is Possible without Major Energy Tradeoff: Life Cycle Assessment of Warmwater Fish Farming in Sweden2020In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 54, no 24, p. 16062-16070Article in journal (Refereed)
    Abstract [en]

    Seafood is seen as promising for more sustainable diets. The increasing production in land-based closed Recirculating Aquaculture Systems (RASs) has overcome many local environmental challenges with traditional open net-pen systems such as eutrophication. The energy needed to maintain suitable water quality, with associated emissions, has however been seen as challenging from a global perspective. This study uses Life Cycle Assessment (LCA) to investigate the environmental performance and improvement potentials of a commercial RAS farm of tilapia and Clarias in Sweden. The environmental impact categories and indicators considered were freshwater eutrophication, climate change, energy demand, land use, and dependency on animal-source feed inputs per kg of fillet. We found that feed production contributed most to all environmental impacts (between 67 and 98%) except for energy demand for tilapia, contradicting previous findings that farm-level energy use is a driver of environmental pressures. The main improvement potentials include improved by-product utilization and use of a larger proportion of plant-based feed ingredients. Together with further smaller improvement potential identified, this suggests that RASs may play a more important role in a future, environmentally sustainable food system.

  • 22.
    Björklund, J.
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Thuresson, K.
    de Wit, C.A.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Perfluorooctane sulfone (PFOS) and perfluorooctanoate (PFOA) in dust from different  indoor environments in Stockholm.2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, p. 2276-2281Article in journal (Refereed)
  • 23.
    Björklund, Justina Awasum
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Thuresson, Kaj
    Cousins, Anna Palm
    Sellström, Ulla
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Emenius, Gunnel
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Indoor Air Is a Significant Source of Tri-decabrominated Diphenyl Ethers to Outdoor Air via Ventilation Systems2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 11, p. 5876-5884Article in journal (Refereed)
    Abstract [en]

    Ventilation of indoor air has been hypothesized to be a source of PBDEs to outdoors. To study this, tri-decabrominated diphenyl ethers were analyzed in outgoing air samples collected inside ventilation systems just before exiting 33 buildings and compared to indoor air samples from microenvironments in each building collected simultaneously. Median Sigma 10PBDE (BDE- 28, -47, -99, -153, -183, -197, -206, -207, -208, -209) concentrations in air from apartment, office and day care center buildings were 93, 3700, and 660 pg/m(3) for outgoing air, and 92, 4700, and 1200 pg/m(3) for indoor air, respectively. BDE-209 was the major congener found. No statistically significant differences were seen for individual PBDE concentrations in matched indoor and outgoing air samples, indicating that outgoing air PBDE concentrations are equivalent to indoor air concentrations. PBDE concentrations in indoor and outgoing air were higher than published outdoor air values suggesting ventilation as a conduit of PBDEs, including BDE-209, from indoors to outdoors. BDE-209 and sum of BDE-28, -47, -99, and -153 emissions from indoor air to outdoors were roughly estimated to represent close to 90% of total emissions to outdoor air for Sweden, indicating that contaminated indoor air is an important source of PBDE contamination to outdoor air.

  • 24.
    Björklund, Justina Awasum
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Thuresson, Kaj
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    De Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Perfluoroalkyl compounds (PFCs) in indoor dust: concentrations, human exposure estimates, and sources2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 7, p. 2276-2281Article in journal (Refereed)
    Abstract [en]

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are globally distributed, persistent, toxic, and are found in human blood and serum. Exposure pathways are not well characterized. To better understand indoor dust ingestion as a potential pathway for human exposure, we determined the concentrations of these compounds in dust collected from 10 houses, 38 apartments, 10 day care centers, 10 offices, and 5 cars. Samples were prepared using a rapid extraction and cleanup method and analyzed using LC-MS/MS. PFOS and PFOA were found in dust samples from all microenvironments and their concentrations were significantly positively correlated to each other. Highest median concentrations were seen in offices (PFOS: 110 ng/g dry weight) and apartments (PFOA: 93 ng/g dw). Adult and toddler dust ingestion exposures were estimated and compared to dietary exposure data from Canada and Spain. Results show that diet is the most important exposure route, but in a worst case scenario, dust ingestion may also be significant.

  • 25. Bogdal, Christian
    et al.
    Muller, Claudia E.
    Buser, Andreas M.
    Wang, Zhanyun
    Scheringer, Martin
    Gerecke, Andreas C.
    Schmid, Peter
    Zennegg, Markus
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Hungerbuhler, Konrad
    Emissions of Polychlorinated Biphenyls, Polychlorinated Dibenzo-p-dioxins, and Polychlorinated Dibenzofurans during 2010 and 2011 in Zurich, Switzerland2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 1, p. 482-490Article in journal (Refereed)
    Abstract [en]

    Persistent organic pollutants (POPs) are ubiquitous contaminants of environmental and human health relevance, but their emissions into the environment are still poorly known. In this study, concentrations of selected POPs were measured in ambient air in Zurich, Switzerland, and interpreted with a multimedia mass balance model. The aim of the combination of measurements and modeling was to back-calculate atmospheric emission rates of POPs. Measurements were performed in summer 2010 and winter 2011 and target analytes included polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Estimated emissions were higher in summer than in winter. Emission estimates for Zurich can be extrapolated to annual averages for Switzerland of 312 kg·a–1 (39 mg·capita–1·a–1), 53 kg·a–1 (7 mg·capita–1·a–1), and 3 kg·a–1 (0.4 mg·capita–1·a–1, 94 g WHO98-TEQ·a–1, 65 g I-TEQ·a–1) for the six indicator PCBs (iPCBs), the twelve coplanar dioxin-like PCBs (dlPCBs), and the 17 2,3,7,8-chlorosubstituted PCDD/Fs, respectively. The emission rates of iPCBs are in agreement with existing emission inventories, whereas for PCDD/Fs the emissions are five times higher than the estimates from the Swiss national emission inventory. Emissions of dlPCBs in Switzerland are presented here for the first time. Our study also provides the first seasonally resolved emission rates of POPs, which were determined with our combined measurement and modeling approach. These findings highlight the relevance of ongoing sources of POPs, even decades after regulations aiming to reduce or eliminate sources were established.

  • 26.
    Bolinius, Damien Johann
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Stockholm Univ, Dept Environm Sci & Analyt Chem ACES, Svante Arrhenius Vag 8, SE-11418 Stockholm, Sweden.
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Iadaresta, Francesco
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Holmbäck, Jan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Lipidor AB, Karolinska Institutet Science Park, Sweden.
    Jahnke, Annika
    Sorptive Capacities of Nonpolymeric Plant Lipids for Hydrophobic Chemicals Determined by Passive Dosing2019In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, no 3, p. 1278-1286Article in journal (Refereed)
    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.

  • 27. Booth, A. Murray
    et al.
    Murphy, Ben
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Stockholm University, Faculty of Science, Department of Meteorology .
    Riipinen, Ilona
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Percival, Carl J.
    Topping, David O.
    Connecting Bulk Viscosity Measurements to Kinetic Limitations on Attaining Equilibrium for a Model Aerosol Composition2014In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, no 16, p. 9298-9305Article in journal (Refereed)
    Abstract [en]

    The growth, composition, and evolution of secondary organic aerosol (SOA) are governed by properties of individual compounds and ensemble mixtures that affect partitioning between the vapor and condensed phase. There has been considerable recent interest in the idea that SOA can form highly viscous particles where the diffusion of either water or semivolatile organics within the particle is sufficiently hindered to affect evaporation and growth. Despite numerous indirect inferences of viscous behavior from SOA evaporation or bounce within aerosol instruments, there have been no bulk measurements of the viscosity of well-constrained model aerosol systems of atmospheric significance. Here the viscous behavior of a well-defined model system of 9 dicarboxylic acids is investigated directly with complementary measurements and model predictions used to infer phase state. Results not only allow us to discuss the atmospheric implications for SOA formation through this representative mixture, but also the potential impact of current methodologies used for probing this affect in both the laboratory and from a modeling perspective. We show, quantitatively, that the physical state transformation from liquid-like to amorphous semisolid can substantially increase the importance of mass transfer limitations within particles by 7 orders of magnitude for 100 nm diameter particles. Recommendations for future research directions are given.

  • 28. Borga, Katrine
    et al.
    Fjeld, Eirik
    Kierkegaard, Amelie
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Consistency in Trophic Magnification Factors of Cyclic Methyl Siloxanes in Pelagic Freshwater Food Webs Leading to Brown Trout2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 24, p. 14394-14402Article in journal (Refereed)
    Abstract [en]

    Cyclic volatile methyl siloxanes (cVMS) concentrations were analyzed in the pelagic food web of two Norwegian lakes (Mjosa, Randsfjorden), and in brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) collected in a reference lake (Femunden), in 2012. Lakes receiving discharge from wastewater treatment plants (Mjosa and Randsfjorden) had cVMS concentrations in trout that were up to 2 orders of magnitude higher than those in Femunden, where most samples were close to the limit of quantification (LOO). Food web biomagnification of cVMS in Mjosa and Randsfjorden was quantified by estimation of trophic magnification factors (TMFs). TMF for legacy persistent organic pollutants (POPs) were analyzed for comparison. Both decamethylcyclopentasiloxane (DS) and dodecamethylcyclohexasiloxane (D6) biomagnified with TMFs of 2.9 (2.1-4.0) and 2.3 (1.8-3.0), respectively. Octamethylcyclotetrasiloxane (D4) was below the LOQ in the majority of samples and had substantially lower biomagnification than for D5 and D6. The cVMS TMFs did not differ between the lakes, whereas the legacy POP TMFs were higher in Mjosa than inRandsfjorden. Whitefish had lower cVMS bioaccumulation compared to legacy POPs, and affected the TMF significance for cVMS, but not for POPs. TMFs of D5 and legacy contaminants in Lake Mjosa were consistent with those previously measured in Mjosa.

  • 29. Borga, Katrine
    et al.
    Fjeld, Eirik
    Kierkegaard, Amelie
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Food Web Accumulation of Cyclic Siloxanes in Lake Mjosa, Norway2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 11, p. 6347-6354Article in journal (Refereed)
    Abstract [en]

    The biomagnification of the cyclic volatile methyl siloxanes octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexatetrasiloxane (D6) was analyzed in the Lake Mjosa food web in Norway from zooplankton and Mysis to planktivorous and piscivorous fish. The trophic magnification factor (TMF) for D5 was determined and compared with TMFs of several legacy contaminants: polychlorinated biphenyl (PCB) congeners 153 and 180, polybrominated diphenyl ether (PBDE) congeners 47 and 99, and p,p'-DDE. D5 showed TMF significantly greater than 1, implying food web biomagnification (TMF = 2.28, CI: 1.22-4.29). This contrasts with two studies that reported TMF < 1, which may reflect variability in TMF between food webs. The Lake Mjosa D5 TMF was sensitive to the species included at the higher trophic level; whole food web TMF differed from TMF excluding smelt (Osmerus eperlanus) or brown trout (Salmo trutta) (TMF-SMELT = 1.62, CI: 0.96-2.72; TMF-TROUT = 3.58, CI: 1.82-7.03). For legacy contaminants (e.g., PCB-153 and PCB-180), the TMFs were less sensitive to the food web composition, and a better model fit was obtained compared to D5. The differences in biomagnification behavior between D5 and the legacy contaminants suggest that the biomagnification of D5 is being governed by species-specific properties such as biotransformation rate or tissue distribution that differ from those of legacy contaminants.

  • 30.
    Bosch, Carme
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Andersson, August
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Kruså, Martin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bandh, Cecilia
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Hovorkova, Ivana
    Klanova, Jana
    Knowles, Timothy D. J.
    Pancost, Richard D.
    Evershed, Richard P.
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    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)2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 13, p. 7657-7665Article in journal (Refereed)
    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.

  • 31. Breivik, Knut
    et al.
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Wania, Frank
    The Emissions Fractions Approach to Assessing the Long-Range Transport Potential of Organic Chemicals2022In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 56, no 17, p. 11983-11990Article in journal (Refereed)
    Abstract [en]

    The assessment of long-range transport potential (LRTP) is enshrined in several frameworks for chemical regulation such as the Stockholm Convention. Screening for LRTP is commonly done with the OECD Pov and LRTP Screening Tool employing two metrics, characteristic travel distance (CTD) and transfer efficiency (TE). Here we introduce a set of three alternative metrics and implement them in the Tool’s model. Each metric is expressed as a fraction of the emissions in a source region. The three metrics quantify the extent to which the chemical (i) reaches a remote region (dispersion, ϕ1), (ii) is transferred to surface media in the remote region (transfer, ϕ2), and (iii) accumulates in these surface media (accumulation, ϕ3). In contrast to CTD and TE, the emissions fractions metrics can integrate transport via water and air, enabling comprehensive LRTP assessment. Furthermore, since there is a coherent relationship between the three metrics, the new approach provides quantitative mechanistic insight into different phenomena determining LRTP. Finally, the accumulation metric, ϕ3, allows assessment of LRTP in the context of the Stockholm Convention, where the ability of a chemical to elicit adverse effects in surface media is decisive. We conclude that the emission fractions approach has the potential to reduce the risk of false positives/negatives in LRTP assessments.

  • 32. Buser, Andreas M.
    et al.
    Kierkegaard, Amelie
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Bogdal, Christian
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Scheringer, Martin
    Hungerbuehler, Konrad
    Concentrations in Ambient Air and Emissions of Cyclic Volatile Methylsiloxanes in Zurich, Switzerland2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 13, p. 7045-7051Article in journal (Refereed)
    Abstract [en]

    Tens of thousands of tonnes of cyclic volatile methylsiloxanes (cVMS) are used each year globally, which leads to high and continuous cVMS emissions to air. However, field measurements of cVMS in air and empirical information about emission rates to air are still limited. Here we present measurements of decamethylcyclopentasfloxane (D-5) and dodecamethylcyclohexasiloxane (D-6) in air for Zurich, Switzerland. The measurements were performed in January and February 2011 over a period of eight days and at two sites (city center and background) with a temporal resolution of 6-12 h. Concentrations of Ds and D-6 are higher in the center of Zurich and range from 100 to 650 ng m(-3) and from 10 to 79 ng m(-3), respectively. These values are among the highest levels of D-5 and D-6 reported in the literature. In a second step, we used a multimedia environmental fate model parametrized for the region of Zurich to interpret the levels and time trends in the cVMS concentrations and to back calculate the emission rates of D-5 and D-6 from the city of Zurich. The average emission rates obtained for D-5 and D-6 are 120 kg d(-1) and 14 kg d(-1), respectively, which corresponds to per capita emissions of 310 mg capita(-1) d(-1) for D-5 and 36 mg capita(-1) d(-1) for D-6.

  • 33.
    Campos, Bruno
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Spain.
    Rivetti, Claudia
    Stockholm University, Faculty of Science, Department of Zoology. nmental Assessment and Water Research (IDAEA-CSIC), Spain.
    Kress, Timm
    Stockholm University, Faculty of Science, Department of Zoology.
    Barata, Carlos
    Dircksen, Heinrich
    Stockholm University, Faculty of Science, Department of Zoology.
    Depressing Antidepressant: Fluoxetine Affects Serotonin Neurons Causing Adverse Reproductive Responses in Daphnia magna2016In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, no 11, p. 6000-6007Article in journal (Refereed)
    Abstract [en]

    Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants. As endocrine disruptive contaminants in the environment, SSRIs affect reproduction in aquatic organisms. In the water flea Daphnia magna, SSRIs increase offspring production in a food ration-dependent manner. At limiting food conditions, females exposed to SSRIs produce more but smaller offspring, which is a maladaptive life-history strategy. We asked whether increased serotonin levels in newly identified serotonin-neurons in the Daphnia brain mediate these effects. We provide strong evidence that exogenous SSRI fluoxetine selectively increases serotonin-immunoreactivity in identified brain neurons under limiting food conditions thereby leading to maladaptive offspring production. Fluoxetine increases serotonin-immunoreactivity at low food conditions to similar maximal levels as observed under high food conditions and concomitantly enhances offspring production. Sublethal amounts of the neurotoxin 5,7-dihydroxytryptamine known to specifically ablate serotonin-neurons markedly decrease serotonin-immunoreactivity and offspring production, strongly supporting the effect to be serotonin-specific by reversing the reproductive phenotype attained under fluoxetine. Thus, SSRIs impair serotonin-regulation of reproductive investment in a planktonic key organism causing inappropriately increased reproduction with potentially severe ecological impact.

  • 34.
    Carrizo, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Distribution and Inventories of Polychlorinated Biphenyls in the Polar Mixed Layer of Seven Pan-Arctic Shelf Seas and the Interior Basins2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 4, p. 1420-1427Article in journal (Refereed)
    Abstract [en]

    Assessment of the Arctic as a global repository of polychlorinated biphenyls (PCBs) and of uptake processes in the base of its marine food chain hinges on reliable information of PCB distribution in surface seawater, yet there is a scarcity of quality-assured PCB measurements in this key compartment. Here, surface seawater PCB concentrations and congener fingerprints are evaluated for all seven pan-Arctic shelf seas and for the interior basins. Particulate and dissolved PCBs were collected via trace-clean protocols on three basin-wide expeditions (AO-01, Beringia-2005, and ISSS-08). Concentrations of the sum of 13 abundant congeners (Sigma(13)PCB) were 0.13-21 pg/L, with higher concentrations in the shelf seas and lower concentrations in the Central Arctic Basin. Trichlorinated PCBs constituted about half of the total loadings in the Eastern Arctic (Beaufort, Chukchi, East Siberian, and Laptev Seas) and in the Central Basin, indicating an atmospheric source. In contrast, hexachlorinated PCBs were more abundant than tri-PCBs in the western sector, suggesting a role also for waterborne transport from regions of heavy PCB consumption in North America and Europe. Finally, the inventory of Sigma(13)PCB in the polar mixed layer of the entire Arctic Ocean was 0.39 ton, which implies that only 0.0008% of historical PCB emissions are now residing in Arctic surface waters.

  • 35.
    Carrizo, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Pan-Arctic River Fluxes of Polychlorinated Biphenyls2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 19, p. 8377-8384Article in journal (Refereed)
    Abstract [en]

    Observations of polychlorinated biphenyls (PCB) concentrations in fluvial surface sediments near the mouths of the six Great Arctic Rivers (GARs; Ob, Yenisey, Lena, Indigirka, Kolyma, and Mackenzie) were combined with annual dissolved organic carbon (DOC) and particulate organic carbon (POC) loadings and hydraulic discharge to estimate the pan-Arctic river flux of PCBs. The highest total-phase fluxes of Sigma(13)PCB were found for the Ob River, with 184 kg/yr and the smallest for the Indigirka River with 3.9 kg/yr. Consistent with a continent-scale trend among the Eurasian GARs of increasing POC concentrations eastward, which is extending to the North American Mackenzie River, a general shift in the estimated PCB partitioning from dissolved to particle-associated flux was found toward the east. Pentachlorinated and hexachlorinated PCBs constituted the majority (>70%) of the total PCB fluxes in the Eurasian Rivers. In contrast, trichlorinated and tetrachlorinated congeners were the most abundant in the Mackenzie (approximate to 75%). The total Sigma(13)PCB fluxes from the pan-Arctic rivers are here estimated to be similar to 0.4 tonne/yr. This is geochemically consistent with the inventory of total PCBs in the Polar Mixed Layer of the entire Arctic Ocean (0.39 tonne) and about a factor 2 less than two new estimates of the PCB settling export to Arctic subsurface waters. Hence, the yearly Great Arctic River PCB fluxes only represent 0.001% of the historical PCB emission into the global environment. To our knowledge, this is the first estimate of circum-Arctic river flux of any organic pollutant based on a comprehensive investigation of the pollutants in several rivers and it contributes toward a more complete understanding of large-scale contaminant cycling in the Arctic.

  • 36. Carrizo, Daniel
    et al.
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Salvadó, Joan A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Spatial Distributions of DDTs in the Water Masses of the Arctic Ocean2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 14, p. 7913-7919Article in journal (Refereed)
    Abstract [en]

    There is a scarcity of data on the amount and distribution of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and its metabolites in intermediate and deep ocean water masses. Here, the distribution and inventories of DDTs in water of the Arctic shelf seas and the interior basin are presented. The occurrence of Sigma 6DDT (0.10-66 pg L-1) in the surface water was dominated by 4,4'-DDE. In the Central Arctic Ocean increasing concentrations of DDE with depth were observed in the Makarov and Amundsen basins. The increasing concentrations down to 2500 m depth is in accordance with previous findings for PCBs and PBDEs. Similar concentrations of DDT and DDEs were found in the surface water, while the relative contribution of DDEs increased with depth, demonstrating a transformation over time and depth. Higher concentrations of DDTs were found in the European part of the Arctic Ocean; these distributions likely reflect a combination of different usage patterns, transport, and fate of these compounds. For instance, the elevated concentrations of DDTs in the Barents and Atlantic sectors of the Arctic Ocean indicate the northbound Atlantic current as a significant conveyor of DDTs. This study contributes to the very rare data on OCPs in the vast deep-water compartments and combined with surface water distribution across the Arctic Ocean helps to improve our understanding of the large-scale fate of DDTs in the Arctic.

  • 37.
    Castro, Mafalda
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Breitholtz, Magnus
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Yuan, Bo
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Partitioning of Chlorinated Paraffins (CPs) to Daphnia magna Overlaps between Restricted and in-Use Categories2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 17, p. 9713-9721Article in journal (Refereed)
    Abstract [en]

    Chlorinated paraffins (CPs) are high-production volume industrial chemicals consisting of n-alkanes (with 10 to 30 carbon atoms in the chain) with chlorine content from 30 to 70% of weight. In Europe, the use of short chain chlorinated paraffins (SCCPs) has been restricted by the Stockholm Convention on POPs due to their PBT (persistent, bioaccumulative and toxic) properties. Medium (MCCPs) and long chain (LCCPs) chlorinated paraffins are used as substitution products. In this work we studied the partitioning behavior of five different CP technical mixtures from the established categories (2 SCCPs, 1 MCCP, 1 LCCP and 1 CP technical mixture covering all categories) using passive dosing, by determining the partitioning coefficient of CP technical mixtures between silicone and water (Ksilicone-water) as well as between organic matter and water (Koc-water). We show that both silicone-water and organic carbon water partition coefficients overlap between different categories of CP technical mixtures. These results indicate that in-use MCCPs and LCCPs may be equally or more bioaccumulative than restricted SCCPs. For the tested mixtures, both chlorine content and carbon chain length showed a significant correlation with both Ksilicone-water and Koc-water.

  • 38.
    Castro, Mafalda
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Yuan, Bo
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Breitholtz, Magnus
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bioaccumulation Potential of CPs in Aquatic Organisms: Uptake and Depuration in Daphnia magna2019In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, no 16, p. 9533-9541Article in journal (Refereed)
    Abstract [en]

    Chlorinated paraffins (CPs) are industrial chemicals, subdivided into three categories: short chain (SCCPs), medium chain (MCCPs), and long chain (LCCPs) chlorinated paraffins. SCCPs are currently restricted in Europe and North America. MC and LCCPs are being used as substitution products, but there is a knowledge gap concerning their bioaccumulation potential in aquatic organisms. In this work, we performed laboratory bioconcentration (passive uptake) and bioaccumulation (including dietary uptake) experiments with Daphnia magna using five different CP technical substances. All tested CP technical substances were bioaccumulative in D. magna, with log BCF and log BAF values ranging between 6.7-7.0 and 6.5-7.0 (L kg lipid(-1)), respectively. An increase in carbon chain length and an increase in chlorine content (% w/w) of the CP technical substances had significant positive effects on the log BCF and log BAF values. For the different CP technical substances, 50% depuration was achieved after 2 to 10 h when D. magna were transferred to clean media. Our results show that SC, MC, and LCCPs are (very)bioaccumulative in aquatic organisms. We believe these data can aid the ongoing policy discussion concerning the environmental risk posed by CPs.

  • 39. Chen, Bing
    et al.
    Andersson, August
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Lee, Meehye
    Kirillova, Elena N.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Xiao, Qianfen
    Kruså, Martin
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Shi, Meinan
    Hu, Ke
    Lu, Zifeng
    Streets, David G.
    Du, Ke
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Source Forensics of Black Carbon Aerosols from China2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 16, p. 9102-9108Article in journal (Refereed)
    Abstract [en]

    The limited understanding of black carbon (BC) aerosol emissions from incomplete combustion causes a poorly constrained anthropogenic climate warming that globally may be second only to CO2 and regionally, such as over East Asia, the dominant driver of climate change. The relative contribution to atmospheric BC from fossil fuel versus biomass combustion is important to constrain as fossil BC is a stronger climate forcer. The source apportionment is the underpinning for targeted mitigation actions. However, technology-based bottom-up emission inventories are inconclusive, largely due to uncertain BC emission factors from small-scale/household combustion and open burning. We use top-down radiocarbon measurements of atmospheric BC from five sites including three city sites and two regional sites to determine that fossil fuel combustion produces 80 +/- 6% of the BC emitted from China. This source-diagnostic radiocarbon signal in the ambient aerosol over East Asia establishes a much larger role for fossil fuel combustion than suggested by all 15 BC emission inventory models, including one with monthly resolution. Our results suggest that current climate modeling should refine both BC emission strength and consider the stronger radiative absorption associated with fossil-fuel-derived BC. To mitigate near-term climate effects and improve air quality in East Asia, activities such as residential coal combustion and city traffic should be targeted.

  • 40.
    Chen, Chang-Er L.
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. South China Normal University, China.
    Löfstrand, Karin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Adolfsson-Erici, Margaretha
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    MacLeod, Matthew
    Deriving in Vivo Bioconcentration Factors of a Mixture of Fragrance Ingredients Using a Single Dietary Exposure and Internal Benchmarking2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 9, p. 5227-5235Article in journal (Refereed)
    Abstract [en]

    Chemicals in mixtures that are hydrophobic with Log K-OW > 4 are potentially bioaccumulative. Here, we evaluate an abbreviated and benchmarked in vivo BCF measurement methodology by exposing rainbow trout to a mixture of eight test chemicals found in fragrance substances and three benchmark chemicals (musk xylene (MX), hexachlorobenzene (HCB) and PCB52) via a single contaminated feeding event followed by a 28-day depuration period. Concentrations of HCB and PCB52 in fish did not decline significantly (their apparent depuration rate constants, k(T), were close to zero), whereas k(T) for MX was 0.022 d(-1). The test chemicals were eliminated much more rapidly than the benchmark chemicals (k(T) > 0.117 d(-1)). The bioconcentration factors (BCFA) for the test chemicals were in the range of 273 L kg(-1) (8-cyclohexadecen-1-one (globanone)) to 1183 L kg(-1) (alpha-pinene); the benchmarked BCFs (BCFG) calculated relative to HCB ranged from 238 L kg(-1) (globanone) to 1147 L kg(-1) (alpha-pinene). BCFG were not significantly different from BCFA but had smaller standard errors. BCFs derived here agreed well with values previously measured using the OECD 305 test protocol. We conclude that it will be feasible to derive BCFs of chemicals in mixtures using a single dietary exposure and chemical benchmarking.

  • 41. Chen, Jie
    et al.
    Hoek, Gerard
    de Hoogh, Kees
    Rodopoulou, Sophia
    Andersen, Zorana J.
    Bellander, Tom
    Brandt, Jørgen
    Fecht, Daniela
    Forastiere, Francesco
    Gulliver, John
    Hertel, Ole
    Hoffmann, Barbara
    Hvidtfeldt, Ulla Arthur
    Verschuren, W. M. Monique
    Jöckel, Karl-Heinz
    Jrgensen, Jeanette T.
    Katsouyanni, Klea
    Ketzel, Matthias
    Méndez, Diego Yacamán
    Leander, Karin
    Liu, Shuo
    Ljungman, Petter
    Faure, Elodie
    Magnusson, Patrik K. E.
    Nagel, Gabriele
    Pershagen, Göran
    Peters, Annette
    Raaschou-Nielsen, Ole
    Rizzuto, Debora
    Stockholm University, Faculty of Social Sciences, Aging Research Center (ARC), (together with KI).
    Samoli, Evangelia
    van der Schouw, Yvonne T.
    Schramm, Sara
    Severi, Gianluca
    Stafoggia, Massimo
    Strak, Maciej
    Sørensen, Mette
    Tjønneland, Anne
    Weinmayr, Gudrun
    Wolf, Kathrin
    Zitt, Emanuel
    Brunekreef, Bert
    Thurston, George D.
    Long-Term Exposure to Source-Specific Fine Particles and Mortality-A Pooled Analysis of 14 European Cohorts within the ELAPSE Project2022In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 56, no 13, p. 9277-9290Article in journal (Refereed)
    Abstract [en]

    We assessed mortality risks associated with sourcespecific fine particles (PM2.5) in a pooled European cohort of 323,782 participants. Cox proportional hazard models were applied to estimate mortality hazard ratios (HRs) for source-specific PM2.5 identified through a source apportionment analysis. Exposure to 2010 annual average concentrations of source-specific PM2.5 components was assessed at baseline residential addresses. The source apportionment resulted in the identification of five sources: traffic, residual oil combustion, soil, biomass and agriculture, and industry. In single-source analysis, all identified sources were significantly positively associated with increased natural mortality risks. In multisource analysis, associations with all sources attenuated but remained statistically significant with traffic, oil, and biomass and agriculture. The highest association per interquartile increase was observed for the traffic component (HR: 1.06; 95% CI: 1.04 and 1.08 per 2.86 mu g/m(3) increase) across five identified sources. On a 1 mu g/m(3) basis, the residual oil-related PM2.5 had the strongest association (HR: 1.13; 95% CI: 1.05 and 1.22), which was substantially higher than that for generic PM2.5 mass, suggesting that past estimates using the generic PM2.5 exposure response function have underestimated the potential clean air health benefits of reducing fossil-fuel combustion. Source-specific associations with cause-specific mortality were in general consistent with findings of natural mortality.

  • 42. Chibwe, Leah
    et al.
    Myers, Anne L.
    De Silva, Amila O.
    Reiner, Eric J.
    Jobst, Karl
    Muir, Derek
    Yuan, Bo
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    C12-30 alpha-Bromo-Chloro Alkenes: Characterization of a Poorly Identified Flame Retardant and Potential Environmental Implications2019In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, no 18, p. 10835-10844Article in journal (Refereed)
    Abstract [en]

    Bromo-chloro alkenes (Br-Cl PXAs) have been used for over 30 years as flame retardants and are listed on several national chemical inventories. Very little publicly available information is available on Br-Cl PXAs, and thus preliminary ecological risk screening is challenging due to the lack of basic information such as molecular structure and associated physicochemical properties. Due to their likely similarity with chlorinated paraffins (CPs), Br-Cl PXAs may pose a similar environmental hazard. Several structural databases list such substances as alkenes, although the industrial synthesis involves halogenation of linear alpha-olefins and would be expected to produce linear alkanes. In this study, a combination of high-resolution separation and mass spectrometric techniques were used to characterize a Br-Cl PXA industrial technical product, C12-30 bromo-chloro alpha-alkenes (CAS RN 68527-01-5). The results show this product is dominated by C-18 carbon chain lengths, substituted with 3-7 chlorine atoms and 1-3 bromine atoms on an alkane chain. Long-chain C-18 chlorinated paraffins are also present, although they represent a relatively minor component. Experimental log K-OW (6.9 to 8.6) and estimated log K-OA (10.5 to 13.5) and log K-AW (-5.1 to -0.6) partition coefficients suggest that this chemical will behave similarly to medium- and long-chain CPs as well as other persistent organic pollutants, such as highly chlorinated pesticides and polychlorinated biphenyls. The results of this study provide an initial step toward understanding the environmental behavior and persistence of Br-Cl PXAs, highlighting the need for further assessment and re-evaluation of the current structure(s) assigned to these compounds.

  • 43. Christiansen, Sigurd
    et al.
    Salter, Matthew E.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Gorokhova, Elena
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nguyen, Quynh T.
    Bilde, Merete
    Sea Spray Aerosol Formation: Laboratory Results on the Role of Air Entrainment, Water Temperature, and Phytoplankton Biomass2019In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, no 22, p. 13107-13116Article in journal (Refereed)
    Abstract [en]

    Sea spray aerosol (SSA) emission is a complex process affected by various controlling factors. This work seeks to deconvolute some of this complexity in a controlled laboratory setting using a plunging jet by varying three key parameters, one at a time: (1) air entrainment rate, (2) seawater temperature, and (3) biomass of phytoplankton. The production of SSA is found to vary linearly with air entrainment rate. By normalizing the production flux to air entrainment rate, we observe nonlinear variation of the production efficiency of SSA with seawater temperature with a minimum around 6-10 degrees C. For comparison, SSA was also generated by detraining air into artificial seawater using a diffuser demonstrating that the production efficiency of SSA generated using a diffuser decreases almost linearly with increasing seawater temperature, and the production efficiency is, significantly higher than that for SSA generated using a plunging jet. Finally, by varying the amount of phytoplankton biomass we demonstrate that SSA particle production varies nonlinearly with the amount of biomass in seawater.

  • 44. Cioni, Lara
    et al.
    Plassmann, Merle
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Benskin, Jonathan P.
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Coêlho, Ana Carolina M. F.
    Nøst, Therese H.
    Rylander, Charlotta
    Nikiforov, Vladimir
    Sandanger, Torkjel M.
    Herzke, Dorte
    Fluorine Mass Balance, including Total Fluorine, Extractable Organic Fluorine, Oxidizable Precursors, and Target Per- and Polyfluoroalkyl Substances, in Pooled Human Serum from the Tromsø Population in 1986, 2007, and 20152023In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 57, no 40, p. 14849-14860Article in journal (Refereed)
    Abstract [en]

    Of the thousands of per- and polyfluoroalkyl substances (PFAS) known to exist, only a small fraction (≤1%) are commonly monitored in humans. This discrepancy has led to concerns that human exposure may be underestimated. Here, we address this problem by applying a comprehensive fluorine mass balance (FMB) approach, including total fluorine (TF), extractable organic fluorine (EOF), total oxidizable precursors (TOP), and selected target PFAS, to human serum samples collected over a period of 28 years (1986, 2007, and 2015) in Tromsø, Norway. While concentrations of TF did not change between sampling years, EOF was significantly higher in 1986 compared to 2007 and 2015. The ∑12PFAS concentrations were highest in 2007 compared to 1986 and 2015, and unidentified EOF (UEOF) decreased from 1986 (46%) to 2007 (10%) and then increased in 2015 (37%). While TF and EOF were not influenced by sex, women had higher UEOF compared to men, opposite to target PFAS. This is the first FMB in human serum to include TOP, and it suggests that precursors with >4 perfluorinated carbon atoms make a minor contribution to EOF (0–4%). Additional tools are therefore needed to identify substances contributing to the UEOF in human serum.

  • 45.
    Coll, Claudia
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science. Swiss Federal Institute of Aquatic Science and Technology, Switzerland.
    Bier, Raven
    Li, Zhe
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Langenheder, Silke
    Gorokhova, Elena
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Association between Aquatic Micropollutant Dissipation and River Sediment Bacterial Communities2020In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 54, no 22, p. 14380-14392Article in journal (Refereed)
    Abstract [en]

    Assessment of micropollutant biodegradation is essential to determine the persistence of potentially hazardous chemicals in aquatic ecosystems. We studied the dissipation half-lives of 10 micropollutants in sediment–water incubations (based on the OECD 308 standard) with sediment from two European rivers sampled upstream and downstream of wastewater treatment plant (WWTP) discharge. Dissipation half-lives (DT50s) were highly variable between the tested compounds, ranging from 1.5 to 772 days. Sediment from one river sampled downstream from the WWTP showed the fastest dissipation of all micropollutants after sediment RNA normalization. By characterizing sediment bacteria using 16S rRNA sequences, bacterial community composition of a sediment was associated with its capacity for dissipating micropollutants. Bacterial amplicon sequence variants of the genera Ralstonia, Pseudomonas, Hyphomicrobium, and Novosphingobium, which are known degraders of contaminants, were significantly more abundant in the sediment incubations where fast dissipation was observed. Our study illuminates the limitations of the OECD 308 standard to account for variation of dissipation rates of micropollutants due to differences in bacterial community composition. This limitation is problematic particularly for those compounds with DT50s close to regulatory persistence criteria. Thus, it is essential to consider bacterial community composition as a source of variability in regulatory biodegradation and persistence assessments.

  • 46. Conley, Daniel J.
    et al.
    Björck, Svante
    Bonsdorff, Erik
    Carstensen, Jacob
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Gustafsson, Bo G.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Hietanen, Susanna
    Kortekaas, Marloes
    Kuosa, Harri
    Meier, H. E. Markus
    Muller-Karulis, Baerbel
    Nordberg, Kjell
    Norkko, Alf
    Nurnberg, Gertrud
    Pitkänen, Heikki
    Rabalais, Nancy N.
    Rosenberg, Rutger
    Savchuk, Oleg P.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Slomp, Caroline P.
    Voss, Maren
    Wulff, Fredrik
    Stockholm University, Faculty of Science, Department of Systems Ecology. Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Zillén, Lovisa
    Hypoxia-Related Processes in the Baltic Sea2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 10, p. 3412-3420Article in journal (Refereed)
    Abstract [en]

    Hypoxia, a growing worldwide problem, has been intermittently present in the modern Baltic Sea since its formation ca. 8000 cal. yr BP. However, both the spatial extent and intensity of hypoxia have increased with anthropogenic eutrophication due to nutrient inputs. Physical processes, which control stratification and the renewal of oxygen in bottom waters, are important constraints on the formation and maintenance of hypoxia. Climate controlled inflows of saline water from the North Sea through the Danish Straits is a critical controlling factor governing the spatial extent and duration of hypoxia. Hypoxia regulates the biogeochemical cycles of both phosphorus (P) and nitrogen (N) in the water column and sediments. Significant amounts of P are currently released from sediments, an order of magnitude larger than anthropogenic inputs. The Baltic Sea is unique for coastal marine ecosystems experiencing N losses in hypoxic waters below the halocline. Although benthic communities in the Baltic Sea are naturally constrained by salinity gradients, hypoxia has resulted in habitat loss over vast areas and the elimination of benthic fauna, and has severely disrupted benthic food webs. Nutrient load reductions are needed to reduce the extent, severity, and effects of hypoxia.

  • 47. Conley, Daniel J.
    et al.
    Bonsdorff, Erik
    Carstensen, Jacob
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Gustafsson, Bo G.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Hansson, Lars-Anders
    Rabalais, Nancy N.
    Voss, Maren
    Zillén, Lovisa
    Tackling hypoxia in the Baltic Sea: Is engineering a solution?2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 10, p. 3407-3411Article in journal (Refereed)
  • 48. Conley, Daniel J.
    et al.
    Carstensen, Jacob
    Aigars, Juris
    Axe, Philip
    Bonsdorff, Erik
    Eremina, Tatjana
    Haahti, Britt-Marie
    Humborg, Christoph
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM). Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Jonsson, Per
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kotta, Jonne
    Lannegren, Christer
    Larsson, Ulf
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Maximov, Alexey
    Medina, Miguel Rodriguez
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Lysiak-Pastuszak, Elzbieta
    Remeikaite-Nikiene, Nijole
    Walve, Jakob
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Wilhelms, Sunhild
    Zillen, Lovisa
    Hypoxia is increasing in the coastal zone of the Baltic Sea2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 16, p. 6777-6783Article in journal (Refereed)
    Abstract [en]

    Hypoxia is a well-described phenomenon in the offshore waters of the Baltic Sea with both the spatial extent and intensity of hypoxia known to have increased due to anthropogenic eutrophication, however, an unknown amount of hypoxia is present in the coastal zone. Here we report on the widespread unprecedented occurrence of hypoxia across the coastal zone of the Baltic Sea. We have identified 115 sites that have experienced hypoxia during the period 1955-2009 increasing the global total to ca. 500 sites, with the Baltic Sea coastal zone containing over 20% of all known sites worldwide. Most sites experienced episodic hypoxia, which is a precursor to development of seasonal hypoxia. The Baltic Sea coastal zone displays an alarming trend with hypoxia steadily increasing with time since the 1950s effecting nutrient biogeochemical processes, ecosystem services, and coastal habitat.

  • 49.
    Cornelissen, Gerard
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Amstaetter, Katja
    Hauge, Audun
    Schaanning, Morten
    Beylich, Bjornar
    Gunnarsson, Jonas S.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Breedveld, Gijs D.
    Oen, Amy M. P.
    Eek, Espen
    Large-Scale Field Study on Thin-Layer Capping of Marine PCDD/F-Contaminated Sediments in Grenlandfjords, Norway: Physicochemical Effects2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 21, p. 12030-12037Article in journal (Refereed)
    Abstract [en]

    A large-scale field experiment on in situ thin-layer capping was carried out in the polychlorinated dibenzodioxin, and dibenzofuran (PCDD/F) contaminated Grenlandsfjords, Norway The main focus of the,trial Was to,test the effectiveness of active caps (targeted thickness of 2.5 cm) consisting of powdered activated carbon (AC) mixed into locally dredged clean clay. Nonactive caps (targed thickness of 5 cm) consisting of clay without, AC as well as crushed limestone were also tested Fields with areas of 10 000 to 40 000 m(2) were established at 30 to 100 m water depth. Auxiliary shaken laboratory batch experiments showed that 2% of the applied powdered AC substantially reduced PCDD/F porewater concentrations, by >90% for tetra-, penta- and hexa-clorinated congeners to 60-70% for octachlorinated ones. In situ AC profiles revealed that the AC was mixed into the sediment to 3 to 5 cm depth in 20 months. Only around 25% of the AC was found inside the pilot fields. Sediment-to-water PCDD/F fluxes measured by in situ diffusion chambers were significantly lower at the capped fields than at reference fields in the same fjord, reductions being largest for the limestone (50-90%) followed by clay (50-70%), and the AC + clay (60%). Also reductions in overlying aqueous PCDD/F concentrations measured by passive samplers were significant in most cases (20-40% reduction), probably because of the large size of the trial fields. The AC was less effective in the field than in the laboratory, probably due to prolonged sediment-to-AC mass transfer times for PCDD/Fs and field factors such as integrity of the cap, new deposition Of contaminated sediment particles, and bioturbation. The present field data indicate that slightly thicker layers of limestone and dredged clay can show as good physicochemical effectiveness as thin caps of AC mixed with clay, at least for PCDD/Fs during the first two years after cap placement.

  • 50.
    Cornelissen, Gerard
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Krusa, Marie Elmquist
    Breedveld, Gijs D.
    Eek, Espen
    Oen, Amy M. P.
    Arp, Hans Peter H.
    Raymond, Caroline
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Samuelsson, Göran
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Hedman, Jenny E.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Stokland, Oystein
    Gunnarsson, Jonas S.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Remediation of Contaminated Marine Sediment Using Thin-Layer Capping with Activated Carbon-A Field Experiment in Trondheim Harbor, Norway2011In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, no 14, p. 6110-6116Article in journal (Refereed)
    Abstract [en]

    In situ amendment of contaminated sediments using activated carbon (AC) is a recent remediation technique, where the strong sorption of contaminants to added AC reduces their release from sediments and uptake into organisms. The current study describes a marine underwater field pilot study in Trondheim harbor, Norway, in which powdered AC alone or in combination with sand or clay was tested as a thin-layer capping material for polycyclic aromatic hydrocarbon (PAH)-contaminated sediment. Several novel elements were included, such as measuring PAH fluxes, no active mixing of AC into the sediment, and the testing of new manners of placing a thin AC cap on sediment, such as AC+clay and AC+sand combinations. Innovative chemical and biological monitoring methods were deployed to test capping effectiveness. In situ sediment-to-water PAH fluxes were measured using recently developed benthic flux chambers. Compared to the reference field, AC capping reduced fluxes by a factor of 2-10. Pore water PAH concentration profiles were measured in situ using anew passive sampler technique, and yielded a reduction factor of 2-3 compared to the reference field. The benthic macrofauna composition and biodiversity were affected by the AC amendments, AC + clay having a lower impact on the benthic taxa than AC-only or AC + sand. In addition, AC + clay gave the highest AC recoveries (60% vs 30% for AC-only and AC + sand) and strongest reductions in sediment-to-water PAH fluxes and porewater concentrations. Thus, application of an AC-clay mixture is recommended as the optimal choice of the currently tested thin-layer capping methods for PAHs, and more research on optimizing its implementation is needed.

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