| 1701. |
- Reth, Margot, et al.
(författare)
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Water-to-air transfer of perfluorinated carboxylates and sulfonates in a sea spray simulator
- 2011
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Ingår i: Environmental Chemistry. - 1448-2517 .- 1449-8979. ; 8:4, s. 381-388
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Tidskriftsartikel (refereegranskat)abstract
- One hypothesis for the origin of perfluorinated alkyl acids, their salts and conjugate bases (here collectively termed PFAAs) in the atmosphere is transfer from the surface ocean by sea spray, the mechanistic explanation being that the surface active properties of PFAAs result in their enrichment on the surface of bursting bubbles. The water-to-air transfer of C(6)-C(14) perfluorocarboxylates (PFCAs) and C(6), C(8) and C(10) perfluorosulfonates (PFSAs) was studied in a laboratory scale sea spray simulator containing tap water spiked with PFCAs and PFSAs. The sequestration of the PFAAs out of bulk water and to the air-water surface was shown to increase exponentially with the length of the perfluorinated alkyl chain. Volatilisation of the PFAAs from an aqueous solution in the absence of spray resulted in less than 1% transfer to the atmosphere during the experiment. In the presence of spray the transfer rate from water to air increased by up to 1360 times. The enhancement was dependent on the PFAA chain length, with the C(6) carboxylate showing an enhancement of a factor of 37, the C(7) carboxylate an enhancement of 320, whereas for all remaining PFAAs the enhancement exceeded 450 with the exception of the C(14) carboxylate (106).
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| 1702. |
- Ripszam, Matyas, 1986-
(författare)
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Bioavailability of organic contaminants in a changing climate
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The effects of predicted future climate change was investigated with special emphasis on the association of organic contaminants with dissolved organic carbon (DOC) in the Baltic Sea.An automated method was developed for the measurements of DOC - water distribution constants at realistic DOC concentrations in brackish water. The method proved to be valid for 30 organic contaminants with different structural elements in the 5 – 100 mg car bon/L DOC concentration range. There were limitations of this method. Firstly, its applicability is limited towards contaminants with lower affinity to DOC. Secondly, at higher (>100 mg carbon/L) DOC concentrations the sorption of contaminants was underest imated.Afterwards, water samples were collected from 15 points within the Baltic Sea in a north - south gradient t o examine the spatial differences in DOC characteristics and sorption properties . The DOC samples were analyzed using proton nuclear magnetic resonance and ultraviolet spectroscopy. Results from both techniques indicated that the aromatic nature of the DOC pool increased towards the northern Baltic Sea. This was expected as the freshwater inflow has high significance in controlling the hydrograp hic conditions in the Bothnian Bay. Sorption of organic contaminants was subsequently measured in the same samples. The results showed decreased sorption from north to south for hydrophobic contaminants such as chlorinated benzenes but for contaminants lik e tributyl - phosphate no spatial tendencies were observed. The data generated was used to determine molecular descriptors of DOC using linear free energy relationships. The results indicated a higher significance of hy drogen bond donor/acceptor functional g roups of the DOC in the south.Changes in contaminant distribution were simulated in model pelagic ecosystems at possible endpoints predicted by future climate change scenarios. Separate and combined effects of temperature a nd DOC were studied in mesocosms. The results indicated interesting tendencies. Increased temperature resulted in increased losses in the amounts of organic contaminants. Increased DOC levels promoted sedimentation and sorption of contaminants to particulate matter and biota. Hi gher amounts of contaminants were retained. The combined effects of the two factors led to and overall decrease in dissolved amounts. Higher losses or increased sedimentation and sorption to particles were also observed depending on contaminant properties.
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| 1703. |
- Rist, Sinja, et al.
(författare)
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A critical perspective on early communications concerning human health aspects of microplastics
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 626, s. 720-726
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Microplastic research in recent years has shown that small plastic particles are found almost everywhere we look. Besides aquatic and terrestrial environments, this also includes aquatic species intended for human consumption and several studies have reported their prevalence in other food products and beverages. The scientific as well as public debate has therefore increasingly focused on human health implications of microplastic exposure. However, there is a big discrepancy between the magnitude of this debate and actual scientific findings, which have merely shown the presence of microplastics in certain products. While plastics can undoubtedly be hazardous to human health due to toxicity of associated chemicals or as a consequence of particle toxicity, the extent to which microplastics in individual food products and beverages contribute to this is debatable. Considering the enormous use of plastic materials in our everyday lives, microplastics from food products and beverages likely only constitute a minor exposure pathway for plastic particles and associated chemicals to humans. But as this is rarely put into perspective, the recent debate has created a skewed picture of human plastic exposure. We risk pulling the focus away from the root of the problem: the way in which we consume, use and dispose of plastics leading to their widespread presence in our everyday life and in the environment. Therefore we urge for a more careful and balanced discussion which includes these aspects.
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| 1704. |
- Rund, Phil, et al.
(författare)
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A Coupled Volatility and Molecular Composition Based Source Apportionment of Atmospheric Organic Aerosol
- 2023
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Ingår i: ACS Earth and Space Chemistry. - 2472-3452. ; 7:7, s. 1365-1377
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Tidskriftsartikel (refereegranskat)abstract
- We apply non-negative matrix factorization (NNMF) to molecular composition and volatility measurements of ambient sub-micrometer particles made using a high-resolution time of flight chemical ionization mass spectrometer (HRToF-CIMS) equipped with a custom filter inlet for gases and aerosols (FIGAERO) as part of the Southern Oxidant and Aerosol Study (SOAS). The resulting factors have a representative thermogram, which carries information on the factor volatility and unique weights for individual ions corresponding to molecular components of measured organic aerosol (OA). These properties and the diurnal patterns of factor weights are used to assign a specific source to each factor. With no a priori information used as input, the routine produces a set of factors with spectra that align well with those previously determined from several laboratory chamber experiments. The factorization routine gains relevance and separation of OA composition when using resolved thermograms as input rather than integrated thermogram time series. Of the seven factors produced by NNMF using the thermogram data, three are attributed to monoterpene-derived OA with extremely low, low, and semivolatile volatility. These three factors together represent 68% of the total organic aerosol mass examined, consistent with previous studies using a spectral basis set. Additionally, two factors were sourced to isoprene chemistry, one representing IEPOX-derived SOA, and the other relating to other oxidation products exhibiting relatively low volatility. The two isoprene-related factors account for 22% of OA mass. Notably absent is a category exclusively capturing the behavior of particulate organic nitrates (PON), which may be consistent with the relatively low local concentrations of PON observed and points to limitations of factorization to fully characterize OA. However, NNMF applied to the volatility and molecular level information from the FIGAERO HRToF-CIMS can resolve dominant precursors and chemical properties of ambient OA components with minimal assumptions.
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| 1705. |
- Schulze, Bastian, et al.
(författare)
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Inter-laboratory mass spectrometry dataset based on passive sampling of drinking water for non-target analysis
- 2021
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Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Non-target analysis (NTA) employing high-resolution mass spectrometry is a commonly applied approach for the detection of novel chemicals of emerging concern in complex environmental samples. NTA typically results in large and information-rich datasets that require computer aided (ideally automated) strategies for their processing and interpretation. Such strategies do however raise the challenge of reproducibility between and within different processing workflows. An effective strategy to mitigate such problems is the implementation of inter-laboratory studies (ILS) with the aim to evaluate different workflows and agree on harmonized/standardized quality control procedures. Here we present the data generated during such an ILS. This study was organized through the Norman Network and included 21 participants from 11 countries. A set of samples based on the passive sampling of drinking water pre and post treatment was shipped to all the participating laboratories for analysis, using one pre-defined method and one locally (i.e. in-house) developed method. The data generated represents a valuable resource (i.e. benchmark) for future developments of algorithms and workflows for NTA experiments.
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| 1706. |
- Schönlau, Christine, 1986-, et al.
(författare)
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Effect-Directed Analysis of Ah Receptor-Mediated Potencies in Microplastics Deployed in a Remote Tropical Marine Environment
- 2019
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Ingår i: Frontiers in Environmental Science. - : Frontiers Media S.A.. - 2296-665X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- To facilitate the study of potential harmful compounds sorbed to microplastics, an effect-directed analysis using the DR CALUX® assay as screening tool for Aryl hydrocarbon receptor (AhR)-active compounds in extracts of marine deployed microplastics and chemical analysis of hydrophobic organic compounds (HOCs) was conducted. Pellets of three plastic polymers [low-density polyethylene (LDPE), high-density polyethylene (HDPE) and high-impact polystyrene (HIPS)] were deployed at Heron Island in the Great Barrier Reef, Australia, for up to 8 months. Detected AhR-mediated potencies (bio-TEQs) of extracted plastic pellets ranged from 15 to 100 pg/g. Contributions of target HOCs to the overall bioactivities were negligible. To identify the major contributors, remaining plastic pellets were used for fractionation with a gas chromatography (GC) fractionation platform featuring parallel mass spectrometric (MS) detection. The bioassay analysis showed two bioactive fractions of each polymer with bio-TEQs ranging from 5.7 to 14 pg/g. High resolution MS was used in order to identify bioactive compounds in the fractions. No AhR agonists could be identified in fractions of HDPE or LDPE. Via a multivariate statistical approach the polystyrene (PS) trimer 1e- Phenyl-4e-(1- phenylethyl)-tetralin was identified in fractions of HIPS and in fractions of the blank polymer of HIPS.
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| 1707. |
- Sedvall, Emelie, et al.
(författare)
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Pharmaceuticals are identified in insects in River Fyris : a study with both tandem quadrupole and quadrupole-time-of-flight mass spectrometry
- 2022
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Ingår i: Environmental Advances. - : Elsevier. - 2666-7657. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The internal concentrations of active pharmaceutical compounds in insects/macroinvertebrates in River Fyris, Uppsala, Sweden, have for the first time been investigated. Specimen of backswimmer, caddisfly larva, damselfly larva, mayfly larva and water louse were caught in the river downstream a waste-water treatment plant. After homogenization and extraction, analysis was carried out with Ultra-High Performance Liquid Chromatography – Electrospray – Tandem Mass Spectrometry (UHPLC-ESI-MS/MS) using both a tandem quadrupole (QqQ) and a quadrupole-time-of-flight (qToF) mass spectrometer. A combined qualitative/quantitative screening method for 89 pharmaceutical compounds in the selective reaction monitoring mode was applied to the samples using the QqQ instrument. Thirty-three different drugs were detected and quantified in the macroinvertebrate samples, covering a wide range of pharmacological classes, the most common being antidepressants, psycholeptics and antihistamines. Drug concentrations up to 260 ng/g (for tetracycline) were determined. A subset of thirteen compounds were selected for a complementary qualitative UHPLC-qToF-MS/MS analysis. This way, the confidence in the substance identifications was significantly strengthened by the availability of full scan high-resolution spectra and accurate mass measurements. This is the first study demonstrating the uptake of pharmaceuticals in water-living macroinvertebrates in Sweden. Since these organisms are in the lower part of the food chain, pharmaceuticals might accumulate in predators leading to ecotoxicological effect at higher trophic levels. Macroinvertebrates might be promising indicator organisms for pharmaceutical pollution.
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| 1708. |
- Seisenbaeva, Gulaim, et al.
(författare)
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Palladium Nanoparticles: Is There a Risk for Aquatic Ecosystems?
- 2016
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Ingår i: Bulletin of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0007-4861 .- 1432-0800. ; 97, s. 153-158
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Tidskriftsartikel (refereegranskat)abstract
- Nano-sized palladium (nano-Pd) is used in catalytic converters of automobiles, where it can be released into the environment by abrasion. Although these particles may subsequently be transported into surface water bodies, no data estimating their fate and toxicity in aquatic systems exists. This study characterized the particle size development of nano-Pd (advertised size *12 nm; hydrodynamic size *70 nm) in media with variable ionic strength (IS). Additionally, the particles' acute toxicity for daphnids and chironomids was assessed. While nano-Pd agglomerated more quickly with increasing IS, it caused only marginal effects in both test species after 96 h of exposure. After 144 h of exposure, however, an EC50 value of 1.23 mg nano-Pd/L for daphnids was determined indicating effects over the long run. When considering the relatively low environmental concentration of elemental Pd in surface waters (usually ng/L), though, this study suggests only a low aquatic risk in response to nano-Pd.
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| 1709. |
- Serk, Henrik, 1980-, et al.
(författare)
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Organochemical characterization of peat reveals decomposition of specific hemicellulose structures as the main cause of organic matter loss in the acrotelm
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 56:23, s. 17410-17419
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Tidskriftsartikel (refereegranskat)abstract
- Peatlands store carbon in the form of dead organic residues. Climate change and human impact impose risks on the sustainability of the peatlands carbon balance due to increased peat decomposition. Here, we investigated molecular changes in the upper peat layers (0-40 cm), inferred from high-resolution vertical depth profiles, from a boreal peatland using two-dimensional 1H-13C nuclear magnetic resonance (NMR) spectroscopy, and comparison to δ13C, δ15N, and carbon and nitrogen content. Effects of hydrological conditions were investigated at respective sites: natural moist, drainage ditch, and natural dry. The molecular characterization revealed preferential degradation of specific side-chain linkages of xylan-type hemicelluloses within 0-14 cm at all sites, indicating organic matter losses up to 25%. In contrast, the xylan backbone, galactomannan-type hemicelluloses, and cellulose were more resistant to degradation and accumulated at the natural moist and drainage site. δ13C, δ15N, and carbon and nitrogen content did not correlate with specific hemicellulose structures but reflected changes in total carbohydrates. Our analysis provides novel insights into peat carbohydrate decomposition and indicates substantial organic matter losses in the acrotelm due to the degradation of specific hemicellulose structures. This suggests that variations in hemicellulose content and structure influence peat stability, which may have important implications with respect to climate change.
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| 1710. |
- Shaltout, Abdallah, et al.
(författare)
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Elemental Composition of PM2.5 Particles Sampled in Industrial and Residential Areas of Taif, Saudi Arabia
- 2013
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Ingår i: Aerosol and Air Quality Research. - : Taiwan Association for Aerosol Research. - 1680-8584 .- 2071-1409. ; 13:4, s. 1356-1364
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the first part of a project conducted to evaluate the trace element composition of atmospheric aerosol particles (PM2.5) and to determine their influence on air quality in Taif city, Saudi Arabia. PM2.5 particles were collected from two different sites (industrial and residential) in Taif during the summer of 2011. The industrial site was situated in the largest industrial area of Taif, and the residential site was situated in the city’s most crowded area. PM2.5 samples were collected on polycarbonate filters using a cyclonic collector. Each sample was collected over a 24 hour period and new samples were collected weekly. Average PM2.5 concentrations of 47 ± 15 and 46 ± 31 μg/m3 were seen in the industrial and residential areas, respectively. An Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer with a Mo secondary target was used to analyze the solid samples because of the relative simplicity of the technique for filter analysis. The use of a Mo secondary target is advantageous, because it decreases the impact of continuum radiation from the X-ray tube and increases the signal to background ratio. Quantitative X-ray Analysis Software (PyMca) was used to perform quantitative analysis of the atmospheric aerosols. The analysis resulted in detected concentrations for sixteen elements; Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Pb and Black Carbon (BC). Using Principal Component Analysis (PCA) it was possible to distinguish between natural and anthropogenic sources. The measured concentrations of the potentially hazardous trace elements Cu, Cr, Mn, Ni and Pb were below the limits defined by international guidelines and national standards for ambient air quality. However, further long-term research will be required to validate the quantification of trace elements in particulate matter in Taif.
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