A global model–measurement evaluation of particle light scattering coefficients at elevated relative humidity

Burgos, M. A.; Andrews, E.; Titos, G.; Benedetti, A.; Bian, H.; Buchard, V.; Curci, G.; Kipling, Z.; Kirkevåg, A.; Kokkola, H.; Laakso, A.; Letertre-Danczak, J.; Lund, M. T.; Matsui, H.; Myhre, G.; Randles, C.; Schulz, M.; van Noije, T.; Zhang, K.; Alados-Arboledas, L.; Baltensperger, U.; Jefferson, A.; Sherman, J.; Sun, J.; Weingartner, E.; Zieger, P.
2020 | Atmos. Chem. Phys. | 20 (10231-10258)

The uptake of water by atmospheric aerosols has a pronounced effect on particle light scattering properties, which in turn are strongly dependent on the ambient relative humidity (RH). Earth system models need to account for the aerosol water uptake and its influence on light scattering in order to properly capture the overall radiative effects of aerosols. Here we present a comprehensive model–measurement evaluation of the particle light scattering enhancement factor f(RH), defined as the particle light scattering coefficient at elevated RH (here set to 85 %) divided by its dry value. The comparison uses simulations from 10 Earth system models and a global dataset of surface-based in situ measurements. In general, we find a large diversity in the magnitude of predicted f(RH) amongst the different models, which can not be explained by the site types. Based on our evaluation of sea salt scattering enhancement and simulated organic mass fraction, there is a strong indication that differences in the model parameterizations of hygroscopicity and model chemistry are driving at least some of the observed diversity in simulated f(RH). Additionally, a key point is that defining dry conditions is difficult from an observational point of view and, depending on the aerosol, may influence the measured f(RH). The definition of dry also impacts our model evaluation, because several models exhibit significant water uptake between RH = 0 % and 40 %. The multisite average ratio between model outputs and measurements is 1.64 when RH = 0 % is assumed as the model dry RH and 1.16 when RH = 40 % is the model dry RH value. The overestimation by the models is believed to originate from the hygroscopicity parameterizations at the lower RH range which may not implement all phenomena taking place (i.e., not fully dried particles and hysteresis effects). This will be particularly relevant when a location is dominated by a deliquescent aerosol such as sea salt. Our results emphasize the need to consider the measurement conditions in such comparisons and recognize that measurements referred to as dry may not be dry in model terms. Recommendations for future model–measurement evaluation and model improvements are provided.

Source quantification of South Asian black carbon aerosols with isotopes and modeling

Sanjeev Dasari; August Andersson; Andreas Stohl; Nikolaos Evangeliou; Srinivas Bikkina; Henry Holmstrand; Krishnakant Budhavant; Abdus Salam; Örjan Gustafsson;
2020 | Environ. Sci. Technol.
black carbon

Characterizing Adduct Formation of Electrophilic Skin Allergens with Human Serum Albumin and Hemoglobin

Lorena Ndreu.; Luke N. Erber; Margareta Törnqvist; Natalia Y. Tretyakova.; Isabella Karlsson
2020 | Chem. Res. Toxicol.

Skin (contact) allergy, the most predominant form of immunotoxicity in humans, is caused by small electrophilic compounds (haptens) that modify endogenous proteins. Approximately 20% of the general population in the Western world is affected by contact allergy. Although the importance of the hapten–protein conjugates is well established in the initiation of the immunological reaction, not much progress has been made regarding identification of these conjugates in vivo or exploration of their potential as diagnostic tools. In this study, the human serum albumin (HSA) and human hemoglobin (Hb) adductome for three representative contact allergens with different chemical properties, 1-chloro-2,4-dinitrobenzene (DNCB), 1,2-epoxy-3-phenoxypropane (PGE), and 2-bromo-2-(bromomethyl)glutaronitrile (MDBGN), were studied. Plasma and red blood cell lysate were used as a source for HSA and Hb, respectively. The Direct Peptide Reactivity Assay was used to investigate adduct formation of MDBGN with nucleophilic moieties and revealed that MDGBN is converted to 2-methylenepentanedinitrile in the presence of sulfhydryl groups prior to adduct formation. Following incubation of HSA and Hb with haptens, an Orbitrap Q Exactive high-resolution mass spectrometer was used to perform an initial untargeted analysis to screen for adduct formation, followed by confirmation by targeted Parallel Reaction Monitoring analysis. Although a subset of adducted sites was confirmed by targeted analysis, only some of the adducted peptides showed an increase in the relative amount of the adducted peptide with an increased concentration of hapten. In total, seven adduct sites for HSA and eight for Hb were confirmed for DNCB and PGE. These sites are believed to be the most reactive. Further, three of the HSA sites (Cys34, Cys62, and Lys190) and six of the Hb sites (subunit α: Val1, His45, His72; subunit β: Cys93, His97, and Cys112) were haptenated already at the lowest level of hapten to protein molar ratio (0.1:1), indicating that these sites are the most likely to be modified in vivo. To the best of our knowledge, this is the first time that the adductome of Hb has been studied in the context of contact allergens. Identification of the most reactive sites of abundant proteins, such as HSA and Hb, is the first step toward identification of contact allergy biomarkers that can be used for biomonitoring and to develop better diagnostic tools based on a blood sample.

The NORMAN Association and the European Partnership for Chemicals Risk Assessment (PARC): let’s cooperate!

Valeria Dulio; Jan Koschorreck; Bert van Bavel; Paul van den Brink; Juliane Hollender; John Munthe; Martin Schlabach; Reza Aalizadeh; Marlene Ågerstrand; Lutz Ahrens; Ian Allan; Nikiforos Alygizakis; Damia’ Barcelo’; Pernilla Bohlin‑Nizzetto; Susanne Boutroup; Werner Brack; Adèle Bressy; Jan H. Christensen; Lubos Cirka; Adrian Covaci; Anja Derksen; Geneviève Deviller; Milou M. L. Dingemans; Magnus Engwall; Despo Fatta‑Kassinos; Pablo Gago‑Ferrero; Félix Hernández; Dorte Herzke; Klára Hilscherová; Henner Hollert; Marion Junghans; Barbara Kasprzyk‑Hordern; Steffen Keiter; Stefan A. E. Kools; Anneli Kruve; Dimitra Lambropoulou; Marja Lamoree; Pim Leonards; Benjamin Lopez; Miren López de Alda; Lian Lundy; Jarmila Makovinská; Ionan Marigómez; Brendan McHugh; Cécile Miège; Simon O’Toole; Noora Perkola; Stefano Polesello; Leo Posthuma; Sara Rodriguez‑Mozaz; Ivo Roessink; Pawel Rostkowski; Heinz Ruedel; Saer Samanipour; Tobias Schulze; Emma L. Schymanski; Manfred Sengl; Peter Tarábek; Dorien Ten Hulscher; Nikolaos Thomaidis; Anne Togola; Sara Valsecchi; Stefan van Leeuwen; Peter von der Ohe; Katrin Vorkamp; Branislav Vrana; Jaroslav Slobodnik
2020 | Environ Sci Eur | 32 (100)

Corrigendum to “Multi-pathway human exposure assessment of phthalate esters and DINCH” [Environ. Int. 112 (2018) 115–126]

Giovanoulis, G.; Bui, T.; Fuchao, X.; Papadopoulou E.; Padilla-Sanchez, J.A.; Covaci, A.; Haug, L.S.; Palm Cousins, A.; Magnér, J.; Cousins, I.T.; de Wit, C.A.
2020 | Environ Int | 143 (106071-(1-5))

Correction to “An (Eco)Toxicity Life Cycle Impact Assessment Framework for Per- And Polyfluoroalkyl Substances”

Holmquist, H.; Fantke, P.; Cousins, I.T.; Owsianiak, M.; Liagkouridis, I.; Peters, G.M.
2020 | Environ. Sci. Technol. | XX (XX) (XXX-XXX)

A global analysis of climate-relevant aerosol properties retrieved from the network of Global Atmosphere Watch (GAW) near-surface observatories

Laj, P.; Bigi, A.; Rose, C.; Andrews, E.; Lund Myhre, C.; Collaud Coen, M.; Lin, Y.; Wiedensohler, A.; Schulz, M.; Ogren, J. A.; Fiebig, M.; Gliß, J.; Mortier, A.; Pandolfi, M.; Petäja, T.; Kim, S.-W.; Aas, W.; Putaud, J.-P.; Mayol-Bracero, O.; Keywood, M.; Labrador, L.; Aalto, P.; Ahlberg, E.; Alados Arboledas, L.; Alastuey, A.; Andrade, M.; Artíñano, B.; Ausmeel, S.; Arsov, T.; Asmi, E.; Backman, J.; Baltensperger, U.; Bastian, S.; Bath, O.; Beukes, J. P.; Brem, B. T.; Bukowiecki, N.; Conil, S.; Couret, C.; Day, D.; Dayantolis, W.; Degorska, A.; Eleftheriadis, K.; Fetfatzis, P.; Favez, O.; Flentje, H.; Gini, M. I.; Gregorič, A.; Gysel-Beer, M.; Hallar, A. G.; Hand, J.; Hoffer, A.; Hueglin, C.; Hooda, R. K.; Hyvärinen, A.; Kalapov, I.; Kalivitis, N.; Kasper-Giebl, A.; Kim, J. E.; Kouvarakis, G.; Kranjc, I.; Krejci, R.; Kulmala, M.; Labuschagne, C.; Lee, H.-J.; Lihavainen, H.; Lin, N.-H.; Löschau, G.; Luoma, K.; Marinoni, A.; Martins Dos Santos, S.; Meinhardt, F.; Merkel, M.; Metzger, J.-M.; Mihalopoulos, N.; Nguyen, N. A.; Ondracek, J.; Pérez, N.; Perrone, M. R.; Petit, J.-E.; Picard, D.; Pichon, J.-M.; Pont, V.; Prats, N.; Prenni, A.; Reisen, F.; Romano, S.; Sellegri, K.; Sharma, S.; Schauer, G.; Sheridan, P.; Sherman, J. P.; Schütze, M.; Schwerin, A.; Sohmer, R.; Sorribas, M.; Steinbacher, M.; Sun, J.; Titos, G.; Toczko, B.; Tuch, T.; Tulet, P.; Tunved, P.; Vakkari, V.; Velarde, F.; Velasquez, P.; Villani, P.; Vratolis, S.; Wang, S.-H.; Weinhold, K.; Weller, R.; Yela, M.; Yus-Diez, J.; Zdimal, V.; Zieger, P.; and Zikova, N.
2020 | Atmos. Meas. Tech. | 13 (4353-4392)

Aerosol particles are essential constituents of the Earth's atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence times, resulting in a highly heterogeneous distribution in space and time. There is a clear need to document this variability at regional scale through observations involving, in particular, the in situ near-surface segment of the atmospheric observation system. This paper will provide the widest effort so far to document variability of climate-relevant in situ aerosol properties (namely wavelength dependent particle light scattering and absorption coefficients, particle number concentration and particle number size distribution) from all sites connected to the Global Atmosphere Watch network. High-quality data from almost 90 stations worldwide have been collected and controlled for quality and are reported for a reference year in 2017, providing a very extended and robust view of the variability of these variables worldwide. The range of variability observed worldwide for light scattering and absorption coefficients, single-scattering albedo, and particle number concentration are presented together with preliminary information on their long-term trends and comparison with model simulation for the different stations. The scope of the present paper is also to provide the necessary suite of information, including data provision procedures, quality control and analysis, data policy, and usage of the ground-based aerosol measurement network. It delivers to users of the World Data Centre on Aerosol, the required confidence in data products in the form of a fully characterized value chain, including uncertainty estimation and requirements for contributing to the global climate monitoring system.

Anisotropic X-Ray Scattering of Transiently Oriented Water

Kim, K. H.; Späh, A.; Pathak, H.; Yang, C.; Bonetti, S.; Amann-Winkel, K.; Mariedahl, D.; Schlesinger, D.; Sellberg, J. A.; Mendez, D.; van der Schot, G.; Hwang, H. Y.; Clark, J.; Shigeki, O.; Tadashi, T.; Harada, Y.; Ogasawara, H.; Katayama, T.; Nilsson, A.; Perakis, F.
2020 | Phys. Rev. Lett. | 125, 076002

We study the structural dynamics of liquid water by time-resolved anisotropic x-ray scattering under the optical Kerr effect condition. In this way, we can separate the anisotropic scattering decay of 160 fs from the delayed temperature increase of ∼0.1  K occurring at 1 ps and quantify transient changes in the O-O pair distribution function. Polarizable molecular dynamics simulations reproduce well the experiment, indicating transient alignment of molecules along the electric field, which shortens the nearest-neighbor distances. In addition, analysis of the simulated water local structure provides evidence that two hypothesized fluctuating water configurations exhibit different polarizability.

Flawed risk assessment of antifouling paints leads to exceedance of guideline values in Baltic Sea marinas

Lagerstrom, M; Ferreira, J; Ytreberg, E; Eriksson-Wiklund, AK
2020 | Springer-Verlag, Germany | 27 (22) (27674-27687)

Organohalogen compounds of emerging concern in Baltic Sea biota: levels, biomagnification potential and comparisons with legacy contaminants.

de Wit, C.A.; Bossi, R.; Dietz, R.; Dreyer, A.; Faxneld, S.; Garbus, S.E.; Hellström, P.; Koschorreck, J.; Lohmann, N.; Roos, A.; Sellström, U.; Sonne, C.; Treu, G.; Vorkamp, K.; Yuan, B.; Eulaers, I.
2020 | Environ Int | 144 (106037-(1-14))

Multidecadal trend analysis of in situ aerosol radiative properties around the world

Collaud Coen, M.; Andrews, E.; Alastuey, A.; Arsov, T. P.; Backman, J.; Brem, B. T.; Bukowiecki, N.; Couret, C.; Eleftheriadis, K.; Flentje, H.; Fiebig, M.; Gysel-Beer, M.; Hand, J. L.; Hoffer, A.; Hooda, R.; Hueglin, C.; Joubert, W.; Keywood, M.; Kim, J. E.; Kim, S.-W.; Labuschagne, C.; Lin, N.-H.; Lin, Y.; Lund Myhre, C.; Luoma, K.; Lyamani, H.; Marinoni, A.; Mayol-Bracero, O. L.; Mihalopoulos, N.; Pandolfi, M.; Prats, N.; Prenni, A. J.; Putaud, J.-P.; Ries, L.; Reisen, F.; Sellegri, K.; Sharma, S.; Sheridan, P.; Sherman, J. P.; Sun, J.; Titos, G.; Torres, E.; Tuch, T.; Weller, R.; Wiedensohler, A.; Zieger, P.; Laj, P.
2020 | Atmos. Chem. Phys. | 20 (8867-8908)

In order to assess the evolution of aerosol parameters affecting climate change, a long-term trend analysis of aerosol optical properties was performed on time series from 52 stations situated across five continents. The time series of measured scattering, backscattering and absorption coefficients as well as the derived single scattering albedo, backscattering fraction, scattering and absorption Ångström exponents covered at least 10 years and up to 40 years for some stations. The non-parametric seasonal Mann–Kendall (MK) statistical test associated with several pre-whitening methods and with Sen's slope was used as the main trend analysis method. Comparisons with general least mean square associated with autoregressive bootstrap (GLS/ARB) and with standard least mean square analysis (LMS) enabled confirmation of the detected MK statistically significant trends and the assessment of advantages and limitations of each method. Currently, scattering and backscattering coefficient trends are mostly decreasing in Europe and North America and are not statistically significant in Asia, while polar stations exhibit a mix of increasing and decreasing trends. A few increasing trends are also found at some stations in North America and Australia. Absorption coefficient time series also exhibit primarily decreasing trends. For single scattering albedo, 52 % of the sites exhibit statistically significant positive trends, mostly in Asia, eastern/northern Europe and the Arctic, 22 % of sites exhibit statistically significant negative trends, mostly in central Europe and central North America, while the remaining 26 % of sites have trends which are not statistically significant. In addition to evaluating trends for the overall time series, the evolution of the trends in sequential 10-year segments was also analyzed. For scattering and backscattering, statistically significant increasing 10-year trends are primarily found for earlier periods (10-year trends ending in 2010–2015) for polar stations and Mauna Loa. For most of the stations, the present-day statistically significant decreasing 10-year trends of the single scattering albedo were preceded by not statistically significant and statistically significant increasing 10-year trends. The effect of air pollution abatement policies in continental North America is very obvious in the 10-year trends of the scattering coefficient – there is a shift to statistically significant negative trends in 2009–2012 for all stations in the eastern and central USA. This long-term trend analysis of aerosol radiative properties with a broad spatial coverage provides insight into potential aerosol effects on climate changes.

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Stockholm University
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