Open questions on atmospheric nanoparticle growth

Yli-Juuti, T; Mohr, C; Riipinen, I
Cloud droplets form in the atmosphere on aerosol particles, many of which result from nucleation of vapors. Here the authors comment on current knowledge and open questions regarding the condensational growth of nucleated particles to sizes where they influence cloud formation.

Dry Generation of CeO2 Nanoparticles and Deposition onto a Co-Culture of A549 and THP-1 Cells in Air-Liquid Interface-Dosimetry Considerations and Comparison to Submerged Exposure

Cappellini, F; Di Bucchianico, S; Karri, V; Latvala, S; Malmlof, M; Kippler, M; Elihn, K; Hedberg, J; Wallinder, IO; Gerde, P; Karlsson, HL
2020 | Nanomaterials | 10 (4)
aerosols , air–liquid interface , ceria , dosimetry , in-vitro , inflammation , nanotoxicology , preciseinhale , size , toxicity
Relevant in vitro assays that can simulate exposure to nanoparticles (NPs) via inhalation are urgently needed. Presently, the most common method employed is to expose lung cells under submerged conditions, but the cellular responses to NPs under such conditions might differ from those observed at the more physiological air-liquid interface (ALI). The aim of this study was to investigate the cytotoxic and inflammatory potential of CeO2 NPs (NM-212) in a co-culture of A549 lung epithelial cells and differentiated THP-1 cells in both ALI and submerged conditions. Cellular dose was examined quantitatively using inductively coupled plasma mass spectrometry (ICP-MS). The role of serum and LPS-priming for IL-1 beta release was further tested in THP-1 cells in submerged exposure. An aerosol of CeO2 NPs was generated by using the PreciseInhale (R) system, and NPs were deposited on the co-culture using XposeALI (R). No or minor cytotoxicity and no increased release of inflammatory cytokines (IL-1 beta, IL-6, TNF alpha, MCP-1) were observed after exposure of the co-culture in ALI (max 5 mu g/cm(2)) or submerged (max 22 mu g/cm(2)) conditions. In contrast, CeO2 NPs cause clear IL-1 beta release in monocultures of macrophage-like THP-1, independent of the presence of serum and LPS-priming. This study demonstrates a useful approach for comparing effects at various in-vitro conditions.

Overview: Integrative and Comprehensive Understanding on Polar Environments (iCUPE) – concept and initial results

Petaja, T; Duplissy, EM; Tabakova, K; Schmale, J; Altstadter, B; Ancellet, G; Arshinov, M; Balin, Y; Baltensperger, U; Bange, J; Beamish, A; Belan, B; Berchet, A; Bossi, R; Cairns, WRL; Ebinghaus, R; El Haddad, I; Ferreira-Araujo, B; Franck, A; Huang, L; Hyvarinen, A; Humbert, A; Kalogridis, AC; Konstantinov, P; Lampert, A; MacLeod, M; Magand, O; Mahura, A; Marelle, L; Masloboev, V; Moisseev, D; Moschos, V; Neckel, N; Onishi, T; Osterwalder, S; Ovaska, A; Paasonen, P; Panchenko, M; Pankratov, F; Pernov, JB; Platis, A; Popovicheva, O; Raut, JC; Riandet, A; Sachs, T; Salvatori, R; Salzano, R; Schroder, L; Schon, M; Shevchenko, V; Skov, H; Sonke, JE; Spolaor, A; Stathopoulos, VK; Strahlendorff, M; Thomas, JL; Vitale, V; Vratolis, S; Barbante, C; Chabrillat, S; Dommergue, A; Eleftheriadis, K; Heilimo, J; Law, KS; Massling, A; Noe, SM; Paris, JD; Prevot, ASH; Riipinen, I; Wehner, B; Xie, ZY; Lappalainen, HK
2020 | Atmos. Chem. Phys. | 20 (14) (8551-8592)
The role of polar regions is increasing in terms of megatrends such as globalization, new transport routes, demography, and the use of natural resources with consequent effects on regional and transported pollutant concentrations. We set up the ERA-PLANET Strand 4 project "iCUPE - integrative and Comprehensive Understanding on Polar Environments" to provide novel insights and observational data on global grand challenges with an Arctic focus. We utilize an integrated approach combining in situ observations, satellite remote sensing Earth observations (EOs), and multi-scale modeling to synthesize data from comprehensive long-term measurements, intensive campaigns, and satellites to deliver data products, metrics, and indicators to stakeholders concerning the environmental status, availability, and extraction of natural resources in the polar areas. The iCUPE work consists of thematic state-of-the-art research and the provision of novel data in atmospheric pollution, local sources and transboundary transport, the characterization of arctic surfaces and their changes, an assessment of the concentrations and impacts of heavy metals and persistent organic pollutants and their cycling, the quantification of emissions from natural resource extraction, and the validation and optimization of satellite Earth observation (EO) data streams. In this paper we introduce the iCUPE project and summarize initial results arising out of the integration of comprehensive in situ observations, satellite remote sensing, and multi-scale modeling in the Arctic context.

Transthyretin-Binding Activity of Complex Mixtures Representing the Composition of Thyroid-Hormone Disrupting Contaminants in House Dust and Human Serum

Hamers, T; Kortenkamp, A; Scholze, M; Molenaar, D; Cenijn, PH; Weiss, JM
2020 | Environ. Health Perspect. | 128 (1)

Dimethylmercury Degradation by Dissolved Sulfide and Mackinawite

West, J; Graham, AM; Van, LN; Jonsson, S
2020 | Environ. Sci. Technol. | 54 (21) (13731-13738)
Potential degradation pathways of dimethylmercury (DMHg) remain as one of the critical knowledge gaps in the marine biogeochemical cycle of mercury (Hg). Although Hg is known to be highly reactive with reduced sulfur, demethylation of DMHg in the presence of sulfide has until now remained experimentally untested. Here, we provide the first experimental support for demethylation of DMHg to monomethylmercury (MMHg) in the presence of both dissolved sulfide and mackinawite (FeS(s)(m)). The degradation of DMHg was shown to be pH dependent, with higher demethylation rates at pH 9 than pH 5. At room temperature and environmentally relevant DMHg to sulfide molar ratios, we observed demethylation rates up to 0.05 d(-1). When comparing the number of active sites available, FeS(s)(m) was found to have a higher capacity to demethylate DMHg, in comparison with dissolved sulfide. Our study suggests that dissolved sulfide and FeS(s)(m) mediated demethylation of DMHg may act as a sink for DMHg, and a potential source of MMHg, in aquatic systems.

Rapid growth of new atmospheric particles by nitric acid and ammonia condensation

Wang, MY; Kong, WM; Marten, R; He, XC; Chen, DX; Pfeifer, J; Heitto, A; Kontkanen, J; Dada, L; Kurten, A; Yli-Juuti, T; Manninen, HE; Amanatidis, S; Amorim, A; Baalbaki, R; Baccarini, A; Bell, DM; Bertozzi, B; Brakling, S; Brilke, S; Murillo, LC; Chiu, R; Chu, BW; De Menezes, LP; Duplissy, J; Finkenzeller, H; Carracedo, LG; Granzin, M; Guida, R; Hansel, A; Hofbauer, V; Krechmer, J; Lehtipalo, K; Lamkaddam, H; Lampimaki, M; Lee, CP; Makhmutov, V; Marie, G; Mathot, S; Mauldin, RL; Mentler, B; Muller, T; Onnela, A; Partoll, E; Petaja, T; Philippov, M; Pospisilova, V; Ranjithkumar, A; Rissanen, M; Rorup, B; Scholz, W; Shen, JL; Simon, M; Sipila, M; Steiner, G; Stolzenburg, D; Tham, YJ; Tome, A; Wagner, AC; Wang, DYS; Wang, YH; Weber, SK; Winkler, PM; Wlasits, PJ; Wu, YH; Xiao, M; Ye, Q; Zauner-Wieczorek, M; Zhou, XQ; Volkamer, R; Riipinen, I; Dommen, J; Curtius, J; Baltensperger, U; Kulmala, M; Worsnop, DR; Kirkby, J; Seinfeld, JH; El-Haddad, I; Flagan, RC; Donahue, NM
2020 | Nature | 581 (7807) (184-+)
A list of authors and their affiliations appears at the end of the paper New-particle formation is a major contributor to urban smog(1,2), but how it occurs in cities is often puzzling(3). If the growth rates of urban particles are similar to those found in cleaner environments (1-10 nanometres per hour), then existing understanding suggests that new urban particles should be rapidly scavenged by the high concentration of pre-existing particles. Here we show, through experiments performed under atmospheric conditions in the CLOUD chamber at CERN, that below about +5 degrees Celsius, nitric acid and ammonia vapours can condense onto freshly nucleated particles as small as a few nanometres in diameter. Moreover, when it is cold enough (below -15 degrees Celsius), nitric acid and ammonia can nucleate directly through an acid-base stabilization mechanism to form ammonium nitrate particles. Given that these vapours are often one thousand times more abundant than sulfuric acid, the resulting particle growth rates can be extremely high, reaching well above 100 nanometres per hour. However, these high growth rates require the gas-particle ammonium nitrate system to be out of equilibrium in order to sustain gas-phase supersaturations. In view of the strong temperature dependence that we measure for the gas-phase supersaturations, we expect such transient conditions to occur in inhomogeneous urban settings, especially in wintertime, driven by vertical mixing and by strong local sources such as traffic. Even though rapid growth from nitric acid and ammonia condensation may last for only a few minutes, it is nonetheless fast enough to shepherd freshly nucleated particles through the smallest size range where they are most vulnerable to scavenging loss, thus greatly increasing their survival probability. We also expect nitric acid and ammonia nucleation and rapid growth to be important in the relatively clean and cold upper free troposphere, where ammonia can be convected from the continental boundary layer and nitric acid is abundant from electrical storms(4,5).

A Novel Framework to Study Trace Gas Transport in Deep Convective Clouds

Bardakov, R; Riipinen, I; Krejci, R; Savre, J; Thornton, JA; Ekman, AML
Deep convective clouds reach the upper troposphere (8-15 km height). In addition to moisture and aerosol particles, they can bring aerosol precursor gases and other reactive trace gases from the planetary boundary layer to the cloud top. In this paper, we present a method to estimate trace gas transport based on the analysis of individual air parcel trajectories. Large eddy simulation of an idealized deep convective cloud was used to provide realistic environmental input to a parcel model. For a buoyant parcel, we found that the trace gas transport approximately follows one out of three scenarios, determined by a combination of the equilibrium vapor pressure (containing information about water-solubility and pure component saturation vapor pressure) and the enthalpy of vaporization. In one extreme, the trace gas will eventually be completely removed by precipitation. In the other extreme, there is almost no vapor condensation on hydrometeors and most of the gas is transported to the top of the cloud. The scenario in between these two extremes is also characterized by strong gas condensation, but a small fraction of the trace gas may still be transported aloft. This approach confirms previously suggested patterns of inert trace gas behavior in deep convective clouds, agrees with observational data, and allows estimating transport in analytically simple and computationally efficient way compared to explicit cloud-resolving model calculations.

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)

Multiple-scattering correction factor of quartz filters and the effect of filtering particles mixed in water: implications for analyses of light absorption in snow samples

Svensson, J; Strom, J; Virkkula, A
2019 | Atmos. Meas. Tech. | 12 (11) (5913-5925)

On the seasonal variation in observed size distributions in northern Europe and their changes with decreasing anthropogenic emissions in Europe: climatology and trend analysis based on 17 years of data from Aspvreten, Sweden

Tunved, Peter; Strom, Johan
2019 | Atmos. Chem. Phys. | 19 (23) (14849-14873)

Influence of Organic Acids on the Surface Composition of Sea Spray Aerosol

Isaak Unger; Clara-Magdalena Saak; Matthew Salter; Paul Zieger; Minna Patanen; Olle Björneholm

Recent studies on sea spray aerosol indicate an enrichment of Ca2+ in small particles, which are often thought to originate from the very surface of a water body when bubbles burst. One model to explain this observation is the formation of ion pairs between Ca2+(aq) and surface-active organic species. In this study, we have used X-ray photoelectron spectroscopy to probe aqueous salt solutions and artificial sea spray aerosol to study whether ion pairing in the liquid environment also affects the surface composition of dry aerosol. Carboxylic acids were added to the sample solutions to mimic some of the organic compounds present in natural seawater. Our results show that the formation of a core–shell structure governs the surface composition of the aerosol. The core–shell structure contrasts previous observations of the dry sea spray aerosol on substrates. As such, this may indicate that substrates can impact the morphology of the dried aerosol.

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