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  • 101.
    Unger, Maria
    et al.
    Department of Applied Environmental Science (ITM), Stockholm University.
    Asplund, Lillemor
    Department of Applied Environmental Science (ITM), Stockholm University.
    Haglund, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Malmvärn, Anna
    Department of Applied Environmental Science (ITM), Stockholm University.
    Arnoldsson, Kristina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Gustafsson, Örjan
    Department of Applied Environmental Science (ITM), Stockholm University.
    Polybrominated and mixed brominated/chlorinated dibenzo-p-dioxins in sponge (Ephydatia fluviatilis) from the Baltic Sea2009Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, nr 21, s. 8245-8250Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polybrominated dibenzo-p-dioxins (PBDDs) have recently been found in the Baltic Sea at concentrations 1000 times above that of the chlorinated analogs (PCDDs), yet their sources are undefined. Marine production of organobrominated compounds by sponges is well documented. The objective of the current study was to investigate the potential for an aquatic sponge (Ephydatia fluviatilis), common to the Baltic Sea, to produce PBDDs and other organobromine compounds in the field. Mono- to pentaBDDs as well as several mixed brominated/chlorinated dibenzo-p-dioxins (Br/Cl-DDs), PCDDs and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were quantified in sponge from the SW Baltic. Concentrations of individual PBDDs in the range 1-80 ng per g extractable organic matter were similar as in blue mussels from the Baltic Sea and about 25 000 times higher than 2,3,7,8-tetraCDD. To the best of our knowledge, this is the first time Br/Cl-DDs are reported in biota from a background environment. While this study does not point out sponges as a dominant source, the concentrations of PBDDs in sponge relative to related anthropogenic compounds such as PBDEs and PCDDs as well as the relative abundance of brominated dioxins and furans strengthens the idea of natural production.

  • 102. Valinia, Salar
    et al.
    Futter, Martyn N.
    Cosby, Bernard J.
    Rosen, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Folster, Jens
    Simple Models to Estimate Historical and Recent Changes of Total Organic Carbon Concentrations in Lakes2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 1, s. 386-394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Quantifying human impacts on the natural environment requires credible reconstructions of reference conditions. Anthropogenic acidification of surface waters is strongly influenced by total organic carbon (TOC) concentrations. Because both the degree of acidification and recovery are dependent on historical TOC concentrations, simple models to estimate changes in surface water TOC between reference conditions (1860) and the present day (2012) are needed. We used visible near infrared spectroscopy (VNIRS) of lake sediments to reconstruct reference condition TOC and long-term monitoring data to predict recent changes. Two empirical models were developed to predict: (i) historical TOC trends between reference conditions (1860) and peak acidification (1980) and (ii) trends in TOC between 1988 and 2012. The models were statistically robust with adj. R(2) of (i) 0.85 and (ii) 0.71, respectively. Models were driven by lake and catchment area, wetlands, historical sulfur deposition and water chemistry. Present day TOC concentrations are similar to VNIRS-reconstructed and modeled reference condition TOC in Swedish lakes. The results are valuable for understanding drivers of TOC changes in lakes and for more credible assessments of reference conditions needed for water management in Europe and elsewhere.

  • 103.
    Vaquer-Sunyer, Raquel
    et al.
    Lund Univ.
    Conley, Daniel J.
    Lund Univ.
    Muthusamy, Sarala Devi
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Lindh, Markus V.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Pinhassi, Jarone
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Kritzberg, Emma S.
    Lund Univ.
    Dissolved Organic Nitrogen Inputs from Wastewater Treatment Plant Effluents Increase Responses of Planktonic Metabolic Rates to Warming2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 19, s. 11411-11420Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Increased anthropogenic pressures on coastal marine ecosystems in the last century are threatening their biodiversity and functioning. Global warming and increases in nutrient loadings are two major stressors affecting these systems. Global warming is expected to increase both atmospheric and water temperatures and increase precipitation and terrestrial runoff, further increasing organic matter and nutrient inputs to coastal areas. Dissolved organic nitrogen (DON) concentrations frequently exceed those of dissolved inorganic nitrogen in aquatic systems. Many components of the DON pool have been shown to supply nitrogen nutrition to phytoplankton and bacteria. Predictions of how global warming and eutrophication will affect metabolic rates and dissolved oxygen dynamics in the future are needed to elucidate their impacts on biodiversity and ecosystem functioning. Here, we experimentally determine simultaneous DON additions and warming on planktonic community metabolism in the Baltic Sea, the largest coastal area suffering from eutrophication-driven hypoxia. Both bacterioplankton community composition and metabolic rates changed in relation to temperature. DON additions from wastewater treatment plant effluents significantly increased the activation energies for community respiration and gross primary production. Activation energies for community respiration were higher than those for gross primary production. Results support the prediction that warming of the Baltic Sea will enhance planktonic respiration rates faster than it will for planktonic primary production. Higher increases in respiration rates than in production may lead to the depletion of the oxygen pool, further aggravating hypoxia in the Baltic Sea.

  • 104.
    Veenaas, Cathrin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Bignert, Anders
    Contaminant Research Group, Swedish Museum of Natural History.
    Liljelind, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Haglund, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Nontarget Screening and Time-Trend Analysis of Sewage Sludge Contaminants via Two-Dimensional Gas Chromatography-High Resolution Mass Spectrometry2018Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, nr 14, s. 7813-7822Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nondestructive sample cleanup and comprehensive two-dimensional gas chromatography (GCXGC) high-resolution mass spectrometry (HRMS) analysis generated a massive amount of data that could be used for nontarget screening purposes. We present a data reduction and prioritization strategy that involves time-trend analysis of nontarget data. Sewage sludge collected between 2005 and 2015 in Stockholm (Sweden) was retrieved from an environmental specimen bank, extracted, and analyzed by GCX GC-HRMS. After data alignment features with high blank levels, artifacts and low detection frequency were removed. Features that appeared in four to six out of ten years were reprocessed to fill in gaps. The total number of compounds was reduced by more than 97% from almost 60 000 to almost 1500. The remaining compounds were analyzed for monotonic (log-linear) and nonmonotonic (smoother) time trends. In total, 192 compounds with log-linear trends and 120 compounds with nonmonotonic trends were obtained, respectively. Most compounds described by a log-linear trend exhibited decreasing trends and were traffic-related. Compounds with increasing trends included UV-filters, alkyl-phenols, and flavor and fragrances, which often could be linked to trade statistics. We have shown that nontarget screening and stepwise reduction of data provides a simple way of revealing significant changes in emissions of chemicals in society.

  • 105.
    Vestergren, Johan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Vincent, Andrea G
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jansson, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Persson, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Istedt, Ulrik
    Department of Forest Ecology & Management, SLU, Umeå, Sweden.
    Gröbner, Gerhard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Schleucher, Jürgen
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    High resolution characterization of organic phosphorus in soil extracts using 2D 1H-31P NMR correlation spectroscopy2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 7, s. 3950-3956Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organic phosphorus (P) compounds represent a major component of soil P in many soils and are key sources of P for microbes and plants. Solution NMR (nuclear magnetic resonance spectroscopy) is a powerful technique for characterizing organic P species. However, <sup>31</sup>P NMR spectra are often complicated by overlapping peaks, which hampers identification and quantification of the numerous P species present in soils. Overlap is often exacerbated by the presence of paramagnetic metal ions, even if they are in complexes with EDTA following NaOH/EDTA extraction. By removing paramagnetic impurities using a new precipitation protocol, we achieved a dramatic improvement in spectral resolution. Furthermore, the obtained reduction in line widths enabled the use of multi-dimensional NMR methods to resolve overlapping <sup>31</sup>P signals. Using the new protocol on samples from two boreal humus soils with different Fe contents, two-dimensional <sup>1</sup>H-<sup>31</sup>P correlation spectra allowed unambiguous identification of a large number of P species based on their <sup>31</sup>P and <sup>1</sup>H chemical shifts and their characteristic coupling patterns, which would not have been possible using previous protocols. This approach can be used to identify organic P species in samples from both terrestrial and aquatic environments, increasing our understanding of organic P biogeochemistry.

  • 106. Violante, Antonio
    et al.
    Del Gaudio, Stefania
    Pigna, Massimo
    Ricciardella, Mariarosaria
    Banerjee, Dipanjan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Coprecipitation of arsenate with metal oxides. 2. Nature, mineralogy, and reactivity of iron(III) precipitates2007Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 41, nr 24, s. 8275-8280Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coprecipitation of arsenic with iron or aluminum occurs in natural environments and is a remediation technology used to remove this toxic metalloid from drinking water and hydrometallurgical solutions. In this work, we studied the nature, mineralogy, and reactivity toward phosphate of iron-arsenate coprecipitates formed at As(V)/Fe(III) molar ratios (R) of 0, 0.01, or 0.1 and at pH 4.0, 7.0, and 10.0 aged for 30 or 210 days at 50 degrees C and studied the desorption of arsenate. At R = 0, goethite and hematite (with ferrihydrite at pH 4.0 and 7.0) crystallized, whereas at R = 0.01, the formation of ferrihydrite increased and hematite crystallization was favored over goethite. In some samples, the morphology of hematite changed from rounded platy crystals to ellipsoids. At R = 0.1, ferrihydrite formed in all the coprecipitates and remained unchanged even after 210 days of aging. The surface area and chemical composition of the precipitates were affected by pH, R, and aging. Chemical dissolution of the samples showed that arsenate was present mainly in ferrihydrite, but at R = 0.01, it was partially incorporated into the structures of crystalline Fe oxides. The sorption of phosphate on to the coprecipitates was affected not only by the mineralogy and surface area of the samples but also by the amounts of arsenate present in the oxides. The samples formed at pH 4.0 and 7.0 and at R = 0.1 sorbed lower amounts of phosphate than the precipitates obtained at R = 0 or 0.01, despite the former having a larger surface area and showing only a presence of short-range ordered materials. This is mainly due to the fact that in the coprecipitates at R = 0.1 arsenate occupied many sorption sites, thus preventing phosphate sorption. Less than 20% of the arsenate present in the coprecipitates formed at R = 0.1 was removed by phosphate and more from the samples synthesized at pH 7.0 or 10.0 than at pH 4.0. Moreover, we found that more arsenate was desorbed by phosphate from a ferrihydrite on which arsenate was added than from an iron-arsenate coprecipitate, attributed to the partial occlusion of some arsenate anions into the framework of the coprecipitate. XPS analyses confirmed these findings.

  • 107. Wan, Moli
    et al.
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Lohmayer, Regina
    Planer-Friedrich, Britta
    Peiffer, Stefan
    Occurrence of Surface Polysulfides during the Interaction between Ferric (Hydr)Oxides and Aqueous Sulfide2014Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 48, nr 9, s. 5076-5084Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polysulfides are often referred to as key reactants in the sulfur cycle, especially during the interaction of ferric (hydr)oxides and sulfide, forming ferrous-sulphide minerals. Despite their potential relevance, the extent of polysulfide formation and its relevance for product formation pathways remains enigmatic. We applied cryogenic X-ray Photoelectron Spectroscopy and wet chemical analysis to study sulfur oxidation products during the reaction of goethite and lepidocrocite with aqueous sulfide at different initial Fe/S molar ratios under anoxic conditions at neutral pH. The higher reactivity of lepidocrocite leads to faster and higher electron turnover compared to goethite. We were able to demonstrate for the first time the occurrence of surface-associated polysulfides being the main oxidation products in the presence of both minerals, with a predominance of disulfide (S22?(surf)), and elemental sulfur. Concentrations of aqueous polysulfide species were negligible (<1%). With prior sulfide fixation by zinc acetate, the surface-associated polysulfides could be precipitated as zerovalent sulfur (S°), which was extracted by methanol thereafter. Of the generated S°, 20?34% were associated with S22?(surf). Varying the Fe/S ratio revealed that surface polysulfide formation only becomes dominant when the remaining aqueous sulfide concentration is low (<0.03 mmol L?1). We hypothesize these novel surface sulfur species, particularly surface disulfide, to act as pyrite precursors. We further propose that these species play an overlooked role in the sulfur cycle.

  • 108. Wiederhold, Jan G.
    et al.
    Skyllberg, Ulf
    Drott, Andreas
    Jiskra, Martin
    Jonsson, Sofi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Björn, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Bourdon, Bernard
    Kretzschmar, Ruben
    Mercury Isotope Signatures in Contaminated Sediments as a Tracer for Local Industrial Pollution Sources2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 1, s. 177-185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) may cause characteristic isotope signatures of different mercury (Hg) sources and help understand transformation processes at contaminated sites. Here, we present Hg isotope data of sediments collected near industrial pollution sources in Sweden contaminated with elemental liquid Hg (mainly chlor-alkali industry) or phenyl-Hg (paper industry). The sediments exhibited a wide range of total Hg concentrations from 0.86 to 99 mu g g(-1)), consisting dominantly of organically-bound Hg and smaller amounts of sulfide-bound Hg. The three phenyl-Hg sites showed very similar Hg isotope signatures (MDF delta Hg-202: -0.2 parts per thousand to -0.5 parts per thousand; MIF Delta Hg-199: -0.05 parts per thousand to -0.10 parts per thousand). In contrast, the four sites contaminated with elemental Hg displayed much greater variations (delta Hg-202: -2.1 parts per thousand to 0.6 parts per thousand; Delta Hg-199: -0.19 parts per thousand to 0.03 parts per thousand) but with distinct ranges for the different sites. Sequential extractions revealed that sulfide-bound Hg was in some samples up to 1 parts per thousand heavier in delta Hg-202 than organically-bound Hg. The selectivity of the sequential extraction was tested on standard materials prepared with enriched Hg isotopes, which also allowed assessing isotope exchange between different Hg pools. Our results demonstrate that different industrial pollution sources can be distinguished on the basis of Hg isotope signatures, which may additionally record fractionation processes between different Hg pools in the sediments.

  • 109. Wincent, Emma
    et al.
    Jonsson, Maria E.
    Bottai, Matteo
    Lundstedt, Staffan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Dreij, Kristian
    Aryl Hydrocarbon Receptor Activation and Developmental Toxicity in Zebrafish in Response to Soil Extracts Containing Unsubstituted and Oxygenated PAHs2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 6, s. 3869-3877Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many industrial sites are polluted by complex mixtures of polycydic aromatic compounds (PACs). Besides polycyclic aromatic hydrocarbons (PAHs), these mixtures often contain significant amounts of more polar PACs including oxygenated PAHs (oxy-PAHs). The effects of oxy-PAHs are, however, poorly known. Here we used zebrafish embryos to examine toxicities and transcriptional changes induced by PAC containing soil extracts from three different industrial sites: a gasworks (GAS), a former wood preservation site (WOOD), and a coke oven (COKE), and to PAR and oxy-PAH containing fractions of these. All extracts induced aryl hydrocarbon receptor (Ahr)-regulated mRNAs, malformations, and mortality. The WOOD extract was most toxic and the GAS extract least toxic. The extracts induced glutathione transferases and heat shock protein 70, suggesting that the toxicity also involved oxidative stress. With all extracts, Ahr2-knock-down reduced the toxicity, indicating a significant Ahr2-dependence on the effects. Ahr2-knock-down was most effective with the PAH fraction of the WOOD extract and with the oxy-PAH fraction of the COKE extract. Our results indicate that oxy-PAH containing mixtures can be as potent Ahr activators and developmental toxicants as PAHs. In addition to Ahr activating potency, the profile of cytochrome P4501 inhibitors may also determine the toxic potency of the extracts.

  • 110.
    Wong, Fiona
    et al.
    Environm Canada, Ctr Atmospher Res Expt, Sci & Technol Branch, Egbert, ON L0L 1N0, Canada.
    Bidleman, Terry F.
    Environm Canada, Ctr Atmospher Res Expt, Sci & Technol Branch, Egbert, ON L0L 1N0, Canada.
    Aging of Organochlorine Pesticides and Polychlorinated Biphenyls in Muck Soil: Volatilization, Bioaccessibility, and Degradation2011Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, nr 3, s. 958-963Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An organic rich muck soil which is highly contaminated with native organochlorine pesticide (OCs) was spiked with known amounts of (13)C-labeled OCs and nonlabeled polychlorinated biphenyls (PCBs). Spiked soils were aged under indoor, outdoor, and sterile conditions and the change in volatility, surrogate bioaccessibility, and degradation of chemicals was monitored periodically over 730 d. Volatility was measured using a fugacity meter to characterize the soil-air partition coefficient (K(SA) = C(SOII)/C(AIR))). The fraction of bioaccessible residues was estimated by comparing recoveries of chemical with a mild extractant, hydroxylpropyl-beta-cyclodextrin (HPCD) vs a harsh extractant, DCM. K(SA) of the spiked OCs in the nonsterile (Indoor, Outdoor) soils were initially lower and approached the K(SA) of native OCs over time, showing reduction of volatility upon aging. HPCD extractability of spiked OCs and PCBs were negatively correlated with K(SA), which suggests that volatility can be used as a surrogate for bioaccessibility. Degradation of endosulfans, PCB 8 and 28 was observed in the nonsterile soils, and (13)C(6)-alpha-HCH showed selective degradation of the (+) enantiomer. Enantiomer fractions (EF) in air and HPCD extracts were lower than in nonsterile soils, suggesting greater sequestering of the (+) enantiomer in the soil during microbial degradation.

  • 111. Wong, Fiona
    et al.
    Jantunen, Liisa M.
    Pucko, Monika
    Papakyriakou, Tim
    Staebler, Ralf M.
    Stern, Gary A.
    Bidleman, Terry F.
    Air-Water Exchange of Anthropogenic and Natural Organohalogens on International Polar Year (IPY) Expeditions in the Canadian Arctic2011Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 45, nr 3, s. 876-881Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Shipboard measurements of organohalogen compounds in air and surface seawater were conducted in the Canadian Arctic in 2007-2008. Study areas included the Labrador Sea, Hudson Bay, and the southern Beaufort Sea. High volume air samples were collected at deck level (6 m), while low volume samples were taken at 1 and 15 m above the water or ice surface. Water samples were taken within 7 m. Water concentration ranges (pg L-1) were as follows: alpha-hexachlorocyclohexane (alpha-HCH) 465-1013, gamma-HCH 150-254, hexachlorobenzene (HCB) 4.0-6.4, 2,4-dibromoanisole (DBA) 8.5-38, and 2,4,6-tribromoanisole (TBA) 4.7-163. Air concentration ranges (pg m(-3)) were as follows: alpha-HCH 7.5-48, gamma-HCH 2.1-7.7, HCB 48-71, DBA 4.8-25, and TBA 6.4 - 39. Fugacity gradients predicted net deposition of HCB in all areas, while exchange directions varied for the other chemicals by season and locations. Net evasion of alpha-HCH from Hudson Bay and the Beaufort Sea during open water conditions was shown by air concentrations that averaged 14% higher at 1 m than 15 m. No significant difference between the two heights was found over ice cover. The alpha-HCH in air over the Beaufort Sea was racemic in winter (mean enantiomer fraction, EF = 0.504 +/- 0.008) and nonracemic in late spring-early summer (mean EF = 0.476 +/- 0.010). This decrease in EF was accompanied by a rise in air concentrations due to volatilization of nonracemic alpha-HCH from surface water (EF = 0.457 +/- 0.019). Fluxes of chemicals during the southern Beaufort Sea open water season (i.e., Leg 9) were estimated using the Whitman two-film model, where volatilization fluxes are positive and deposition fluxes are negative. The means +/- SD (and ranges) of net fluxes (ng m(-2) d(-1)) were as follows: alpha-HCH 6.8 +/- 3.2 (2.7-13), gamma-HCH 0.76 +/- 0.40 (0.26-1.4), HCB -9.6 +/- 2.7 (-6.1 to -15), DBA 1.2 +/- 0.69 (0.04-2.0), and TBA 0.46 +/- 1.1 ng m(-2) d(-1) (-1.6 to 2.0).

  • 112. Wong, Fiona
    et al.
    Kurt-Karakus, Perihan
    Bidleman, Terry F.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Fate of Brominated Flame Retardants and Organochlorine Pesticides in Urban Soil: Volatility and Degradation2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 5, s. 2668-2674Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As the uses of polybrominated diphenyl ethers (BDEs) are being phased out in many countries, soils could become a secondary emission source to the atmosphere. It is also anticipated that the demand for alternative brominated flame retardants (BFRs) will grow, but little is known about their environmental fate in soils. In this study, the volatility degradation of BFRs and organochlorine pesticides (OCPS) in soil was investigated. A low organic carbon (5.6%) urban soil was spiked with a suite of BFRs and OCPs, followed by incubation under laboratory condition for 360 days. These included BDE- 17, -28, -47, -99; alpha- and beta-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), beta-1,2,5,6-tetrabromocyclooctane (TBCO), and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), OCPs: a-hexachlorocyclohexane (alpha-HCH) and C-13(6)-alpha-HCH, trans-chlordane (TC), and C-13(10)-TC. The volatility of spiked chemicals was investigated using a fugacity meter to measure the soil-air partition coefficient (K-SA). K-SA of some spiked BFRs and OCPs increased from Day 10 to 60 or 90 and leveled off afterward. This suggests that the volatility of BFRs and OCPs decreases over time as the chemicals become more strongly bound to the soil. Degradation of alternative BFRs (alpha- and beta-TBECH, beta-TBCO, DPTE), BDE-17, and alpha-HCH (C-13-labeled and nonlabeled) was evident in soils over 360 days, but no degradation was observed for the BDE-28, -47, -99, and TC (C-13-labeled and nonlabeled). A method to separate the enantiomers of alpha-TBECH and beta-TBCO was developed and their degradation, along with alpha-HCH (C-13-labeled and nonlabeled) was enantioselective. This is the first study which reports the enantioselective degradation of chiral BFRs in soils. Discrepancies between the enantiomer fraction (EF) of chemicals extracted from the soil by dichloromethane (DCM) and air were found. It is suggested that DCM removes both the sequestered and loosely bound fractions of chemicals in soil, whereas air accesses only the loosely bound fraction, and these two pools are subject to different degrees of enantioselective degradation. This calls for caution when interpreting EFs obtained from DCM extraction of soil with EFs in ambient air.

  • 113. Xu, Jing
    et al.
    Marsac, Remi
    Costa, Dominique
    Cheng, Wei
    Wu, Feng
    Boily, Jean-Francois
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Hanna, Khalil
    Co-Binding of Pharmaceutical Compounds at Mineral Surfaces: Molecular Investigations of Dimer Formation at Goethite/Water Interfaces2017Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, nr 15, s. 8343-8349Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The emergence of antibiotic and anti-inflammatory agents in aquatic and terrestrial systems is becoming a serious threat to human and animal health worldwide. Because pharmaceutical compounds rarely exist individually in nature, interactions between various compounds can have unforeseen effects on their binding to mineral surfaces. This work demonstrates this important possibility for the case of two typical antibiotic and anti-inflammatory agents (nalidixic acid (NA) and niflumic acid (NFA)) bound at goethite (alpha FeOOH) used as a model mineral surface. Our multidisciplinary study, which makes use of batch sorption experiments, vibration spectroscopy and periodic density functional theory calculations, reveals enhanced binding of the otherwise weakly bound NFA caused by unforeseen intermolecular interactions with mineral-bound NA. This enhancement is ascribed to the formation of a NFA NA dimer whose energetically favored formation (-0.5 eV compared to free molecules) is predominantly driven by van der Waals interactions. A parallel set of efforts also showed that no. cobinding occurred with sulfamethoxazole (SMX) because of the lack of molecular interactions with coexisting contaminants. As such, this article raises the importance of recognizing drug cobinding, and lack of cobinding, for predicting and developing policies on the fate of complex mixtures of antibiotics and anti-inflammatory agents in nature.

  • 114. Xu, Jing
    et al.
    Marsac, Remi
    Wei, Cheng
    Wu, Feng
    Boily, Jean-François
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Hanna, Khalil
    Cobinding of Pharmaceutical Compounds at Mineral Surfaces: Mechanistic Modeling of Binding and Cobinding of Nalidixic Acid and Niflumic Acid at Goethite Surfaces2017Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, nr 20, s. 11617-11624Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although emerging contaminants rarely exist individually in environmental contaminated systems, only limited information on their adsorption mechanisms in multi-component solutions is currently available. To address this shortcoming, this work examines for the first time the accuracy of a surface complexation model in predicting the cooperative adsorption of nalidixic acid (NA) and niflurnic acid (NFA) at goethite (alpha-FeOOH) surfaces. Our model adequately predicts cobinding of an outer-sphere (OS) complex of NFA onto NA bound to goethite through metal-bonded (MB), hydrogen-bonded (HB), or OS complexes. More positive charge is introduced in the system via sodium interactions in order to describe the NFA adsorption at high NaCl concentrations in both single and binary systems. Our model confidently predict multilayers of NA on goethite as well as NFA binding on goethite-bound NA over a large range of pH and salinity values as well as NA and NFA loadings. These findings have strong implications in the assessment and prediction of contaminant fate in multicomponent contaminated systems by invoking a nontraditional form of ligand-ligand interaction in this field of study.

  • 115.
    Zhang, Jin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Begum, Afshan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Brännström, Kristoffer
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Grundström, Christin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Iakovleva, Irina
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Olofsson, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Sauer-Eriksson, A. Elisabeth
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Andersson, Patrik L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Structure-based Virtual Screening Protocol for in silico Identification of Potential Thyroid Disrupting Chemicals Targeting Transthyretin2016Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, nr 21, s. 11984-11993Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thyroid disruption by xenobiotics is associated with a broad spectrum of severe adverse outcomes. One possible molecular target of thyroid hormone disrupting chemicals (THDCs) is transthyretin (TTR), a thyroid hormone transporter in vertebrates. To better understand the interactions between TTR and THDCs, we determined the crystallographic structures of human TTR in complex with perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and 2,2',4,4'-tetrahydroxybenzophenone (BP2). The molecular interactions between the ligands and TTR were further characterized using molecular dynamics simulations. A structure-based virtual screening (VS) protocol was developed with the intention of providing an efficient tool for the discovery of novel TTR-binders from the Tox21 inventory. Among the 192 predicted binders, 12 representatives were selected, and their TTR binding affinities were studied with isothermal titration calorimetry, of which seven compounds had binding affinities between 0.26 and 100 mu M. To elucidate structural details in their binding to TTR, crystal structures were determined of TTR in complex with four of the identified compounds including 2,6-dinitro-p-cresol, bisphenol S, clonixin, and triclopyr. The compounds were found to bind in the TTR hormone binding sites as predicted. Our results show that the developed VS protocol is able to successfully identify potential THDCs, and we suggest that it can be used to propose THDCs for future toxicological evaluations.

  • 116.
    Zhang, Jin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Grundström, Christin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Brännström, Kristoffer
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Iakovleva, Irina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Lindberg, Mikael J.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Olofsson, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk kemi och biofysik.
    Andersson, Patrik L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Sauer-Eriksson, A. Elisabeth
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Interspecies variation between fish and human transthyretins in their binding of thyroid-disrupting chemicals2018Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, nr 20, s. 11865-11874Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thyroid-disrupting chemicals (TDCs) are xenobiotics that can interfere with the endocrine system and cause adverse effects in organisms and their offspring. TDCs affect both the thyroid gland and regulatory enzymes associated with thyroid hormone homeostasis. Transthyretin (TTR) is found in the serum and cerebrospinal fluid of vertebrates, where it transports thyroid hormones. Here, we explored the interspecies variation in TDC binding to human and fish TTR (exemplified by Gilthead seabream (Sparus aurata)). The in vitro binding experiments showed that TDCs bind with equal or weaker affinity to seabream TTR than to the human TTR, in particular, the polar TDCs (>500-fold lower affinity). Crystal structures of the seabream TTR TDC complexes revealed that all TDCs bound at the thyroid binding sites. However, amino acid substitution of Ser117 in human TTR to Thr117 in seabream prevented polar TDCs from binding deep in the hormone binding cavity, which explains their low affinity to seabream TTR Molecular dynamics and in silico alanine scanning simulation also suggested that the protein backbone of seabream TTR is more rigid than the human one and that Thr117 provides fewer electrostatic contributions than Ser117 to ligand binding. This provides an explanation for the weaker affinities of the ligands that rely on electrostatic interactions with Thr117. The lower affinities of TDCs to fish TTR, in particular the polar ones, could potentially lead to milder thyroid-related effects in fish.

  • 117.
    Zhang, Jin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Kamstra, Jorke H.
    Ghorbanzadeh, Mehdi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Weiss, Jana M.
    Hamers, Timo
    Andersson, Patrik L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    In Silico Approach To Identify Potential Thyroid Hormone Disruptors among Currently Known Dust Contaminants and Their Metabolites2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 16, s. 10099-10107Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thyroid hormone disrupting chemicals (THDCs) interfere with the thyroid hormone system and may induce multiple severe physiological disorders. Indoor dust ingestion is a major route of THDCs exposure in humans, and one of the molecular targets of these chemicals is the hormone transporter transthyretin (TTR). To virtually screen indoor dust contaminants and their metabolites for THDCs targeting TTR, we developed a quantitative structure activity relationship (QSAR) classification model. The QSAR model was applied to an in-house database including 485 organic dust contaminants reported from literature data and their 433 in silico derived metabolites. The model predicted 37 (7.6%) dust contaminants and 230 (53.1%) metabolites as potential TTR binders. Four new THDCs were identified after testing 23 selected parent dust contaminants in a radio-ligand TTR binding assay; 2,2',4,4'-tetrahydroxybenzophenone, perfluoroheptanesulfonic acid, 3,5,6-trichloro-2-pyridinol, and 2,4,5-trichlorophenoxyacetic acid. These chemicals competitively bind to TTR with 50% inhibition (IC50) values at or below 10 mu M. Molecular docking studies suggested that these THDCs interacted similarly with TTR via the residue Ser117A, but their binding poses were dissimilar to the endogenous ligand T4. This study identified new THDCs using an in silico approach in combination with bioassay testing and highlighted the importance of metabolic activation for TTR binding.

  • 118. Zhang, Lin
    et al.
    Bidleman, Terry F
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Perry, Mary Jane
    Lohmann, Rainer
    Fate of chiral and achiral organochlorine pesticides in the North Atlantic Bloom experiment2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 15, s. 8106-8114Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organochlorine pesticides (OCPs) were measured in the surface seawater and lower atmosphere during the North Atlantic Bloom Experiment in the spring 2008 from samples collected on the R/V Knorr. The gaseous concentration profiles resulted from both long-range transport (LRT) from the Arctic by polar easterlies and local biogeochemical processes. Relatively constant alpha/gamma-hexachlorocyclohexane (HCH) ratios and enantiomer fractions of alpha-HCH indicated that a single water mass was sampled throughout the cruise. Changes in dissolved phase concentrations were dominated by bloom processes (air-water exchange, partitioning to organic particles, and subsequent sinking) rather than LRT. alpha-HCH and dissolved phase trans-chlordanes showed depletion of (+) enantiomer, whereas depletion of the (-) enantiomer was observed for heptachlor exoepoxide (HEPX) and cis-chlordanes. Fugacity ratio calculations suggest that hexachlorobenzene (HCB) and gamma-HCH were depositing from air to water whereas heavier OCPs (chlordanes, HEPX) were evaporating. Dissolved phase concentrations did not decrease with time during the three-week bloom period; neither were lipophilic OCPs drawn down from air to water as previous studies hypothesized. Comparison with Arctic measurements suggested that the Arctic returned higher concentrations of alpha-HCH and HCB through both the atmospheric (polar easterlies) as well as oceanic transport (East Greenland Current) to the lower latitudes.

  • 119.
    Zheng, Ziye
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Peters, Gregory M.
    Arp, Hans Peter H.
    Andersson, Patrik L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Combining in Silico Tools with Multicriteria Analysis for Alternatives Assessment of Hazardous Chemicals: A Case Study of Decabromodiphenyl Ether Alternatives2019Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, nr 11, s. 6341-6351Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alternatives assessment is applied for minimizing the risk of unintentionally replacing a hazardous chemical with another hazardous chemical. Central challenges are the diversity of properties to consider and the lack of high-quality experimental data. To address this, a novel alternatives assessment procedure was developed based on in silico data and multicriteria decision analysis (MCDA) methods. As a case study, 16 alternatives to the flame retardant decabromodiphenyl ether were considered. The hazard properties included persistence (P), bioaccumulation potential (B), toxicities (T), and mobility in water (M). Databases were consulted and 2866 experimental data points were collected for the target chemicals; however, these were mostly replicate data points for some hazard criteria for a subset of alternatives. Therefore, in silico data and three MCDA strategies were tested including heat mapping, multiattribute utility theory (MAUT), and Elimination Et Choix Traduisant la REalite (ELECTRE III). The heat map clearly showed that none of the target chemicals are hazard-free, whereas MAUT and ELECTRE III agreed on ranking the "least worst" choices. This study identified several challenges and the complexity in the alternatives assessment processes motivating more case studies combining in silico and MCDA approaches.

  • 120. Zhou, Lian
    et al.
    Martin, Sébastien
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, France.
    Cheng, Wei
    Lassabatere, Laurent
    Boily, Jean-Francois
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Hanna, Khalil
    Water Flow Variability Affects Adsorption and Oxidation of Ciprofloxacin onto Hematite2019Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 53, nr 17, s. 10102-10109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mobility of pharmaceuticals in environmental systems is under great scrutiny in the scientific literature and in the press. Still, very few reports have focused on redox-driven transformations when these compounds are bound to mineral surfaces, and how their transport is affected under flow-through conditions. In this study, we examined the adsorption and electron transfer reactions of ciprofloxacin (CIP) in a dynamic column containing nanosized hematite (α-Fe2O3). CIP binding and the subsequent redox transformation were strongly dependent on inflow pH and residence time. These reactions could be predicted using transport models that account for adsorption and transformation kinetics. Our results show that flow interruption over a 16 h period triggers oxidation of hematite-bound CIP into byproducts. These reactions are likely facilitated by inner-sphere iron–CIP complexes formed via the sluggish conversion from outer-sphere complexes during interrupted flow. When intermittent flow/no-flow conditions were applied sequentially, a second byproduct was detected in the column effluent. This work sheds light on a much overseen aspect of redox transformations of antibiotics under flow-through conditions. It has important implications in adequately predicting transport, and in developing risk assessments of these emerging compounds in the environment.

  • 121. Ågerstrand, Marlene
    et al.
    Berg, Cecilia
    Björlenius, Berndt
    Breitholtz, Magnus
    Brunström, Björn
    Fick, Jerker
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Gunnarsson, Lina
    Göteborg, Sweden; Exeter, United Kingdom.
    Larsson, D. G. Joakim
    Göteborg, Sweden.
    Sumpter, John P.
    Uxbridge, United Kingdom.
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Rudén, Christina
    Improving Environmental Risk Assessment of Human Pharmaceuticals2015Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, nr 9, s. 5336-5345Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents 10 recommendations for improving the European Medicines Agency's guidance for environmental risk assessment of human pharmaceutical products. The recommendations are based on up-to-date, available science in combination with experiences from other chemical frameworks such as the REACH-legislation for industrial chemicals. The recommendations concern: expanding the scope of the current guideline; requirements to assess the risk for development of antibiotic resistance; jointly performed assessments; refinement of the test proposal; mixture toxicity assessments on active pharmaceutical ingredients with similar modes of action; use of all available ecotoxicity studies; mandatory reviews; increased transparency; inclusion of emission data from production; and a risk management option. We believe that implementation of our recommendations would strengthen the protection of the environment and be beneficial to society. Legislation and guidance documents need to be updated at regular intervals in order to incorporate new knowledge from the scientific community. This is particularly important for regulatory documents concerning pharmaceuticals in the environment since this is a research field that has been growing substantially in the last decades.

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