Liposome-mediated delivery of challenging chemicals to aid environmental assessment of Bioaccumulative (B) and Toxic (T) properties

Castro, M; Lindqvist, D
2020 | Sci Rep | 10 (1)
acids , daphnia-magna , drug-delivery , fish , hydrophobic chemicals , organic chemicals , substances , systems , volatile
Standard aquatic toxicity tests of chemicals are often limited by the chemicals' water solubility. Liposomes have been widely used in the pharmaceutical industry to overcome poor pharmacokinetics and biodistribution. In this work, liposomes were synthesized and used in an ecotoxicological context, as a tool to assure stable dosing of technically challenging chemicals to zooplankton. Three chemicals with distinctly different characteristics were successfully incorporated into the liposomes: Tetrabromobisphenol A (TBBPA, log K-ow 5.9, pK(a1) 7.5, pK(a2) 8.5), chlorinated paraffin CP-52 (log K-ow 8-12) and perfluorooctanoic acid (PFOA, pK(a) 2.8). The size, production yield and stability over time was similar for all blank and chemical-loaded liposomes, except for when the liposomes were loaded with 10 or 100mgg(-1) PFOA. PFOA increased the size and decreased the production yield and stability of the liposomes. Daphnia magna were exposed to blank and chemical-loaded liposomes in 48hour incubation experiments. A dose-dependent increase in body burden in D. magna and increased immobilization (LD50=7.6ng CPs per individual) was observed. This confirms not only the ingestion of the liposomes but also the successful internalization of chemicals. This study shows that liposomes can be a reliable alternative to aid the study of aquatic toxicity of challenging chemicals.

Corrigendum to “Properties, performance and associated hazards of state-of-the-art durable water repellent (DWR) chemistry for textile finishing” [Environ. Int. 91 (2016) 251-264]

Holmquist, H.; Schellenberger, S.; van der Veen, I.; Peters, G.M.; Leonards, P.E.G.; Cousins, I.T.
2020 | Environ Int | 134 (105289-105289)

The Roles of the Atmosphere and Ocean in Driving Arctic Warming Due to European Aerosol Reductions

Krishnan, S; Ekman, AML; Hansson, HC; Riipinen, I; Lewinschal, A; Wilcox, LJ; Dallafior, T
2020 | Geophys Res Lett | 47 (7)
Clean air policies can have significant impacts on climate in remote regions. Previous modeling studies have shown that the temperature response to European sulfate aerosol reductions is largest in the Arctic. Here we investigate the atmospheric and ocean roles in driving this enhanced Arctic warming using a set of fully coupled and slab-ocean simulations (specified ocean heat convergence fluxes) with the Norwegian Earth system model (NorESM), under scenarios with high and low European aerosol emissions relative to year 2000. We show that atmospheric processes drive most of the Arctic response. The ocean pathway plays a secondary role inducing small temperature changes mostly in the opposite direction of the atmospheric response. Important modulators of the temperature response patterns are changes in sea ice extent and subsequent turbulent heat flux exchange, suggesting that a proper representation of Arctic sea ice and turbulent changes is key to predicting the Arctic response to midlatitude aerosol forcing. Plain Language Summary Aerosols are liquid or solid particles suspended in air, which may have adverse air quality and health impacts. Sulfate aerosols also have a cooling influence on climate and can mask some of the greenhouse gas-induced global warming. While aerosol emissions are variable in space and time, their impacts are not limited to where they are emitted. In fact, studies using global climate models have shown that changing sulfur dioxide emissions in Europe can have significant impacts on Arctic climate. Here we investigate the roles of changes in atmospheric and ocean heat transport in driving these changes in the Arctic by conducting a series of climate model simulations with specified anthropogenic sulfur dioxide emissions and different ocean heat transport fluxes. We find that changes through the atmosphere play a primary role in affecting the Arctic climate. These changes are modulated by changes in sea ice extent and the energy exchange between ocean and atmosphere in the sub-Arctic. Aerosol-driven changes in ocean heat transport play a smaller, secondary role in the Arctic and tend to reduce the impacts. Our results show that the proper representation of Arctic sea ice is crucial for accurately modeling the Arctic response to changes in midlatitude aerosol forcing.

Formation and mobilization of methylmercury across natural and experimental sulfur deposition gradients

Akerblom, S; Nilsson, MB; Skyllberg, U; Bjorn, E; Jonsson, S; Ranneby, B; Bishop, K
2020 | Environ. Pollut. | 263
accumulation , acid rain , boreal peatland , dissolved organic matter , global change , mercury , methyl mercury , methylation , nitrogen , peatland , sediments , sulfur , water , yellow perch
We investigated the influence of sulfate (SO42-) deposition and concentrations on the net formation and solubility of methylmercury (MeHg) in peat soils. We used data from a natural sulfate deposition gradient running 300 km across southern Sweden to test the hypothesis posed by results from an experimental field study in northern Sweden: that increased loading of SO42- both increases net MeHg formation and redistributes methylmercury (MeHg) from the peat soil to its porewater. Sulfur concentrations in peat soils correlated positively with MeHg concentrations in peat porewater, along the deposition gradient similar to the response to added SO42- in the experimental field study. The combined results from the experimental field study and deposition gradient accentuate the multiple, distinct and interacting roles of SO42- deposition in the formation and redistribution of MeHg in the environment. (c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (

Intact Ether Lipids in Trench Sediments Related to Archaeal Community and Environmental Conditions in the Deepest Ocean

Xu, YP; Wu, WC; Xiao, WJ; Ge, HM; Wei, YL; Yin, XR; Yao, HM; Lipp, JS; Pan, BB; Hinrichs, KU
2020 | J. Geophys. Res.-Biogeosci. | 125 (7)
ammonia-oxidizing archaea , archaea , biomarker , carbon , challenger deep , diversity , gdgt , hadal zone , intact polar lipid , mass spectrometry , membrane-lipids , organic-matter , oxygen , polar lipids , tetraether lipids , tex86
Archaea play an important role in marine biogeochemical cycle; however, their phylogenetic distribution and lipid composition in the hadal zone (6-11 km water depth) are poorly known. Here, we analyzed archaeal membrane lipids and 16S rRNA gene sequences in sediments from Mariana Trench (MT), Massau Trench (MS), and New Britain Trench (NBT), varying from 1,560 to 10,840 m depth. Forty-two intact polar lipids (IPLs) were identified, including glycerol dialkyl glycerol tetraethers (GDGTs), OH-GDGTs, glycerol dialkyl diethers (GDDs), and archaeol (AR) with polar headgroups of monohexose (1G), dihexose (2G), trihexose (3G), and hexose-phosphohexose (HPH). Compositional and spatial distribution patterns of archaeal lipids suggest benthic Thaumarchaeota as a major source for IPLs, consistent with the predominance of Thaumarchaeota genes (>80%). The redundancy analysis (RDA) based on lipid and 16S rRNA data separates samples into three groups: extremely deep water (MT), significant terrestrial influence (NBT 1, 4, and 6), and predominant marine influence (MS, NBT 2, 3, 7, and 10). 1G-GDDs and 1G-AR positively correlate with water depth, likely reflecting the adaptation of benthic archaea to elevated hydrostatic pressure or variation of archaeal community in trench sediments. Bathyarchaeota are more abundant in sediments receiving terrestrial input; this pattern was attributed to their capability of utilizing terrestrial organic matter as an energy source. Our study highlights important environmental influences (e.g., pressure and organic matter quality and quantity) on benthic archaeal community and archaeal IPL compositions, which should be considered when IPLs and core lipids are applied as chemotaxonomic markers and paleo-proxies.

Screening of halogenated phenolic compounds in plasma and serum from marine wildlife

2020 | Int. J. Environ. Sci. Technol. | 17 (4) (2177-2184)
analysis , bde-47 , bioaccumulation , biotransformation , blood , fate , food , hydroxylated polychlorinated-biphenyls , mass spectral library , pbdes , phenols , polybrominated diphenyl ethers , retention index
The growing knowledge of the impact of halogenated phenolic compounds on hormonal and metabolic systems has led to an increased interest in the exposure and potential effects of these compounds in wildlife. In the present study, a screening procedure was developed to detect and quantify halogenated phenolic compounds in serum and plasma from marine wildlife. A mass spectral library containing selective ion monitoring data was created using gas chromatography electron capture negative ionization mass spectrometry. The selective ion monitoring data in the library were accompanied with retention indices to increase the specificity of each entry in the library. The library together with the developed extraction procedure and optimized instrumental settings can be used for the detection of 52 different halogenated phenolic compounds of environmental concern, including 23 hydroxylated polychlorinated biphenyls and 24 hydroxylated polybrominated diphenyl ethers. The instrument limit of detection for the compounds included in the library ranged from 30 to 320 fg/injection, with a median detection limit of 90 fg/injection. The average recovery of 11 different halogenated phenolic compounds, from four species of marine wildlife, was 66 +/- 14%. A full-scan mass spectral library was also created containing an additional seven compounds. Gray seals, long-tailed ducks, and two species of fish from the Baltic Sea were screened for halogenated phenolic compounds using the developed procedure. A total of 33 compounds included in the library were detected and quantified.

Resolving Ambient Organic Aerosol Formation and Aging Pathways with Simultaneous Molecular Composition and Volatility Observations

Lee, B; D'Ambro, EL; Lopez-Hilfiker, FD; Schobesberger, S; Mohr, C; Zawadowicz, MA; Liu, JM; Shilling, JE; Hu, WW; Palm, BB; Jimenez, JL; Hao, LQ; Virtanen, A; Zhang, HF; Goldstein, AH; Pye, HOT; Thornton, JA
2020 | ACS EARTH AND SPACE CHEMISTRY | 4 (3) (391-402)
alpha-pinene , ambient measurements , atmospheric simulation chamber , gas , hydrolysis , kinetics , mass-spectrometer , oh , ozonolysis , phase , soa formation , source and chemistry attribution , southeast united-states
Organic aerosol (OA) constitutes a significant fraction of atmospheric fine particle mass. However, the precursors and chemical processes responsible for a majority of OA are rarely conclusively identified. We use online observations of hundreds of simultaneously measured molecular components obtained from 15 laboratory OA formation experiments with constraints on their effective saturation vapor concentrations to attribute the volatile organic compound (VOC) precursors and subsequent chemical pathways giving rise to the vast majority of OA mass measured in two forested regions. We find that precursors and chemical pathways regulating OA composition and volatility are dynamic over hours to days, with their variations driven by coupled interactions between multiple oxidants. The extent of physical and photochemical aging, and its modulation by NOx, was key to a uniquely comprehensive combined composition-volatility description of OA. Our findings thus provide some of the most complete mechanistic-level guidance to the development of OA descriptions in air quality and earth system models.

On the fate of oxygenated organic molecules in atmospheric aerosol particles

Pospisilova, V; Lopez-Hilfiker, FD; Bell, DM; El Haddad, I; Mohr, C; Huang, W; Heikkinen, L; Xiao, M; Dommen, J; Prevot, ASH; Baltensperger, U; Slowik, JG
2020 | Sci. Adv. | 6 (11)
alpha-pinene , autoxidation , chemistry , mass spectrometry , oxidation , ozonolysis , part 1 , particulate matter , peroxides , spectrometer eesi-tof
Highly oxygenated organic molecules (HOMs) are formed from the oxidation of biogenic and anthropogenic gases and affect Earth's climate and air quality by their key role in particle formation and growth. While the formation of these molecules in the gas phase has been extensively studied, the complexity of organic aerosol (OA) and lack of suitable measurement techniques have hindered the investigation of their fate post-condensation, although further reactions have been proposed. We report here novel real-time measurements of these species in the particle phase, achieved using our recently developed extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF). Our results reveal that condensed-phase reactions rapidly alter OA composition and the contribution of HOMs to the particle mass. In consequence, the atmospheric fate of HOMs cannot be described solely in terms of volatility, but particle-phase reactions must be considered to describe HOM effects on the overall particle life cycle and global carbon budget.

Evaluating Organic Aerosol Sources and Evolution with a Combined Molecular Composition and Volatility Framework Using the Filter Inlet for Gases and Aerosols (FIGAERO)

Thornton, JA; Mohr, C; Schobesberger, S; D'Ambro, EL; Lee, B; Lopez-Hilfiker, FD
2020 | Acc. Chem. Res. | 53 (8) (1415-1426)
The complex array of sources and transformations of organic carbonaceous material that comprises an important fraction of atmospheric fine particle mass, known as organic aerosol, has presented a long running challenge for accurate predictions of its abundance, distribution, and sensitivity to anthropogenic activities. Uncertainties about changes in atmospheric aerosol particle sources and abundance over time translate to uncertainties in their impact on Earth's climate and their response to changes in air quality policy. One limitation in our understanding of organic aerosol has been a lack of comprehensive measurements of its molecular composition and volatility, which can elucidate sources and processes affecting its abundance. Herein we describe advances in the development and application of the Filter Inlet for Gases and Aerosols (FIGAERO) coupled to field-deployable High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometers (HRToF-CIMS). The FIGAERO HRToFCIMS combination broadly probes gas and particulate OA molecular composition by using programmed thermal desorption of particles collected on a Teflon filter with subsequent detection and speciation of desorbed vapors using inherently quantitative selected-ion chemical ionization. The thermal desorption provides a means to obtain quantitative insights into the volatility of particle components and thus the physicochemical nature of the organic material that will govern its evolution in the atmosphere. In this Account, we discuss the design and operation of the FIGAERO, when coupled to the HRToF-CIMS, for quantitative characterization of the molecular-level composition and effective volatility of organic aerosol in the laboratory and field. We provide example insights gleaned from its deployment, which improve our understanding of organic aerosol sources and evolution. Specifically, we connect thermal desorption profiles to the effective equilibrium saturation vapor concentration and enthalpy of vaporization of detected components. We also show how application of the FIGAERO HRToF-CIMS to environmental simulation chamber experiments and the field provide new insights and constraints on the chemical mechanisms governing secondary organic aerosol formation and dynamic evolution. We discuss the associated challenges of thermal decomposition during desorption and calibration of both the volatility axis and signal. We also illustrate how the FIGAERO HRToF-CIMS can provide additional insights into organic aerosol through isothermal evaporation experiments as well as for detection of ultrafine particulate composition. We conclude with a description of future opportunities and needs for its ability to further organic aerosol science.

MIMiX: a Multipurpose In situ Microreactor system for X-ray microspectroscopy to mimic atmospheric aerosol processing

Forster, JD; Gurk, C; Lamneck, M; Tong, HJ; Ditas, F; Steimer, SS; Alpert, PA; Ammann, M; Raabe, J; Weigand, M; Watts, B; Poschl, U; Andreae, MO; Pohlker, C
2020 | Atmos. Meas. Tech. | 13 (7) (3717-3729)
beamline , cluster-analysis , humidified tdma , hygroscopic growth measurements , ice nucleation , particle critical supersaturation , phase state , physical state , spectromicroscopy , water activities

The dynamic processing of aerosols in the atmosphere is difficult to mimic under laboratory conditions, particularly on a single-particle level with high spatial and chemical resolution. Our new microreactor system for X-ray microscopy facilitates observations under in situ conditions and extends the accessible parameter ranges of existing setups to very high humidities and low temperatures. With the parameter margins for pressure (180-1000 hPa), temperature (similar to 250 K to room temperature), and relative humidity (similar to 0% to above 98 %), a wide range of tropospheric conditions is covered. Unique features are the mobile design and compact size that make the instrument applicable to different synchrotron facilities. Successful first experiments were conducted at two X-ray microscopes, MAXYMUS, located at beamline UE46 of the synchrotron BESSY II, and PolLux, located at beamline X07DA of the Swiss Light Source in the Paul Scherrer Institute. Here we present the design and analytical scope of the system, along with first results from hydration-dehydration experiments on ammonium sulfate and potassium sulfate particles and the tentative observation of water ice at low temperature and high relative humidity in a secondary organic aerosol particle from isoprene oxidation.

Fostering multidisciplinary research on interactions between chemistry, biology, and physics within the coupled cryosphere-atmosphere system

Thomas, J.L.; Stutz, J.; Frey, M.M.; Bartels-Rausch, T.; Altieri, K.; Baladima, F.; Browse, J.; Dall’Osto, M.; Marelle, L.; Mouginot, J.; Murphy, J.G.; Nomura, D.; Pratt, K.A.; Willis, M.D.; Zieger, P.; Abbatt, J.; Douglas, T.A.; Facchini, M.C.; France, J.; Jones, A.E.; Kim, K.; Matrai, P.A.; McNeill, V.F.; Saiz-Lopez, A.; Shepson, P.; Steiner, N.; Law, K.S.; Arnold, S.R.; Delille, B.; Schmale, J.; Sonke, J.E.; Dommergue, A.; Voisin, D.; Melamed, M.L.; Gier, J.
2019 | Elementa - Science of the Anthropocene | 7 (1)

The cryosphere, which comprises a large portion of Earth’s surface, is rapidly changing as a consequence of global climate change. Ice, snow, and frozen ground in the polar and alpine regions of the planet are known to directly impact atmospheric composition, which for example is observed in the large influence of ice and snow on polar boundary layer chemistry. Atmospheric inputs to the cryosphere, including aerosols, nutrients, and contaminants, are also changing in the anthropocene thus driving cryosphere-atmosphere feedbacks whose understanding is crucial for understanding future climate. Here, we present the Cryosphere and ATmospheric Chemistry initiative (CATCH) which is focused on developing new multidisciplinary research approaches studying interactions of chemistry, biology, and physics within the coupled cryosphere – atmosphere system and their sensitivity to environmental change. We identify four key science areas: (1) micro-scale processes in snow and ice, (2) the coupled cryosphere-atmosphere system, (3) cryospheric change and feedbacks, and (4) improved decisions and stakeholder engagement. To pursue these goals CATCH will foster an international, multidisciplinary research community, shed light on new research needs, support the acquisition of new knowledge, train the next generation of leading scientists, and establish interactions between the science community and society.

Year-Round In Situ Measurements of Arctic Low-Level Clouds: Microphysical Properties and Their Relationships With Aerosols

Koike, M; Ukita, J; Strom, J; Tunved, P; Shiobara, M; Vitale, V; Lupi, A; Baumgardner, D; Ritter, C; Hermansen, O; Yamada, K; Pedersen, CA
2019 | J. Geophys. Res.-Atmos. | 124 (3) (1798-1822)

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