A Random Forest Approach to Estimate Daily Particulate Matter, Nitrogen Dioxide, and Ozone at Fine Spatial Resolution in Sweden

Stafoggia, M.; Johansson, C.; Glantz, P.; Renzi, M.; Shtein, A.; de Hoogh, K.; Kloog, I.; Davoli, M.; Michelozzi, P.; Bellander, T.
2020 | ATMOSPHERE | 11 (239) (1-19)

Air pollution is one of the leading causes of mortality worldwide. An accurate assessment
of its spatial and temporal distribution is mandatory to conduct epidemiological studies able to
estimate long-term (e.g., annual) and short-term (e.g., daily) health effects. While spatiotemporal
models for particulate matter (PM) have been developed in several countries, estimates of daily
nitrogen dioxide (NO2) and ozone (O3) concentrations at high spatial resolution are lacking, and no
such models have been developed in Sweden. We collected data on daily air pollutant
concentrations from routine monitoring networks over the period 2005–2016 and matched them
with satellite data, dispersion models, meteorological parameters, and land-use variables. We
developed a machine-learning approach, the random forest (RF), to estimate daily concentrations
of PM10 (PM<10 microns), PM2.5 (PM<2.5 microns), PM2.5–10 (PM between 2.5 and 10 microns), NO2,
and O3 for each squared kilometer of Sweden over the period 2005–2016. Our models were able to
describe between 64% (PM10) and 78% (O3) of air pollutant variability in held-out observations, and
between 37% (NO2) and 61% (O3) in held-out monitors, with no major differences across years and
seasons and better performance in larger cities such as Stockholm. These estimates will allow to
investigate air pollution effects across the whole of Sweden, including suburban and rural areas,
previously neglected by epidemiological investigations.

A simple field-based biodegradation test shows pH to be an inadequately controlled parameter in laboratory biodegradation testing

2020 | Environ. Sci.: Processes Impacts | 22 (1006-1013)

Complex mixtures of chlorinated paraffins found in handwipes from a Norwegian cohort.

Yuan, B.; Tay, J.H.; Papadopoulou, E.; Haug, L.S.; Padilla-Sánchez, J.A.; de Wit, C.A.
2020 | Environ. Sci. Technol. Lett. | 7 (198-205)

Chlorinated paraffins in snakes from paddy fields in Yangtze River Delta: Occurrence, tissue distribution and biomagnification.

Du, X.; Yuan, B.; Zhou, Y.; de Wit, C.A.; Zheng, Z.; Yin, G.
2020 | Environ. Sci. Technol. | 54 (2753-2762)

DNA epigenetic marks are linked to embryo aberrations in amphipods

Gorokhova, E; Martella, G; Motwani, HN; Tretyakova, N; Sundelin, B; Motwani, HV
2020 | Sci Rep | 10:665

Serum albumin adducts, DNA adducts and micronuclei frequency measured in benzo[a]pyrene-exposed mice for estimation of genotoxic potency

Motwani, HV; Westberg, E, Lindh, C; Abramsson-Zetterberg, L; Törnqvist, M.
2020 | Mutat. Res. | 849

Radiometric Survey of the Tyaa River Sand Mine In Kitui, Kenya.

S. M. Matsitsi; J. M. Linturi; J. M. Kebwaro; Leonard Kirago
2020 | Radiat Prot Dosimetry | 188 (4) (405-412)

Severe thiamine deficiency in eastern Baltic cod (Gadus morhua)

Engelhardt J; Frisell O; Gustavsson H; Hansson T; Sjöberg R; Collier TK; Balk L
2020 | PLoS ONE

Evaluation of the OECD POV and LRTP screening tool for estimating the long-range transport of organophosphate esters

Sühring R, Scheringer M, Jantunen L, Diamond ML
2020 | Environ. Sci.-Process Impacts

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.

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.

Contact information

Visiting addresses:

Geovetenskapens Hus,
Svante Arrhenius väg 8, Stockholm

Arrheniuslaboratoriet, Svante Arrhenius väg 16, Stockholm (Unit for Toxicological Chemistry)

Mailing address:
Department of Environmental Science
Stockholm University
106 91 Stockholm

Press enquiries should be directed to:

Stella Papadopoulou
Science Communicator
Phone +46 (0)8 674 70 11