Véronique Riffault

• PhD in Chemistry
• Professor (Full) at IMT Nord Europe

Understanding the interaction of anthropogenic and biogenic emissions around large urban agglomerations remains an important question for atmospheric research and the key question of the ACROSS (Atmospheric Chemistry of the Suburban Forest) project. ACROSS is based on an intensive field campaign in the Paris area, including ground-based measurement...

The complex refractive index (CRI; n−ik) and the single scattering albedo (SSA) are key parameters driving the aerosol direct radiative effect. Their spatial, temporal, and spectral variabilities in anthropogenic–biogenic mixed environments are poorly understood. In this study, we retrieve the spectral CRI and SSA (370–950 nm wavelength range) from...

The apportionment of equivalent black carbon (eBC) to combustion sources from liquid fuels (mainly fossil; eBCLF) and solid fuels (mainly non-fossil; eBCSF) is commonly performed using data from Aethalometer instruments (AE approach). This study evaluates the feasibility of using AE data to determine the absorption Ångström exponents (AAEs) for liq...

Investigating the current and future evolution of surface solar radiation (SSR) is essential in the context of climate change and associated environmental issues. We focus on the influence of atmospheric aerosols, along with cloud cover and water vapor content, on northern France and Benelux in spring and summer. Our analysis relies on the National...

Carbonaceous aerosols (CA), composed of black carbon (BC) and organic matter (OM), significantly impact the climate. Light absorption properties of CA, particularly of BC and brown carbon (BrC), are crucial due to their contribution to global and regional warming. We present the absorption properties of BC (bAbs,BC) and BrC (bAbs,BrC) inferred usin...

This paper presents a first comprehensive analysis of long-term measurements of atmospheric aerosol components from aerosol chemical speciation monitor (ACSM) and multiwavelength Aethalometer (AE33) instruments collected between 2015 and 2021 at 13 (sub)urban sites as part of the French CARA (Chemical Characterization of Particles) program. The dat...

The interaction of anthropogenic and biogenic emissions around large urban agglomerations remains an important question for atmospheric research and the key question of the ACROSS (Atmospheric Chemistry of the Suburban Forest) project. ACROSS is based on an intensive field campaign in the Paris area, including ground–based measurements in the urban...

The complex refractive index (CRI, n−ik) and the single scattering albedo (SSA) are key parameters driving the aerosol direct radiative effect. Their spatial, temporal, and spectral variabilities in anthropogenic−biogenic mixed environments are poorly understood. In this study, we retrieve the spectral CRI and SSA (370−950 nm wavelength range) from...

Fine particulate matter (PM2.5) was monitored at five rural background locations in France from 2012 to 2021. Annual PM2.5 ranged from 5 to 15 μg m–3, all sites repeatedly exceeding the 2021 annual World Health Organization guideline. Chemical speciation including organic and elemental carbon (OC, EC), secondary inorganic aerosols (SIA: NO3–, SO42–...

Understanding the lifecycle of light-absorbing carbonaceous aerosols, from emission to deposition, is critical for assessing their climate impact. This study integrated multi-year aerosol observations from the ATOLL (ATmospheric Observations in liLLe, northern France) platform, with air mass back trajectories and emission inventory as a newly devel...

This paper presents a first comprehensive analysis of long-term measurements of atmospheric aerosol components from Aerosol Chemical Speciation Monitor (ACSM) and multi-wavelength Aethalometer (AE33) instruments collected between 2015 and 2021 at 13 (sub)urban sites as part of the French CARA program. The datasets contain the mass concentrations of...

Improving knowledge of current and future spatio-temporal variability of surface solar radiation is essential in the context of climate change and associated environmental and societal issues. Such an evolution will be influenced by changes in both meteorological parameters and atmospheric composition, notably by anthropogenic emissions. We investi...

The Aerosol, Clouds and Trace Gases Research Infrastructure (ACTRIS) officially became the 33 rd European Research Infrastructure Consortium (ERIC) on April 25, 2023 with the support of 17 founding member and observer countries. As a pan-European legal organization, ACTRIS ERIC will coordinate the provision of data and data products on short-lived...

Terpenoids have long been known to originate from natural sources. However, there is growing evidence for emissions from anthropogenic activities in cities, in particular from the production, manufacturing, and use of household solvents. Here, as part of the DATAbASE (Do Anthropogenic Terpenoids mAtter in AtmoSpheric chEmistry?) project, we investi...

Understanding the lifecycle of light-absorbing carbonaceous aerosols, from emission to deposition, is critical for assessing their climate impact. This study integrated multi-year aerosol observations from the ATOLL (Lille metropolis, northern France) platform, with air mass back-trajectories and emission inventory as a newly developed ‘INTERPLAY’...

Under the EU Air Quality Directive (AQD) 2008/50/EC member states are required to undertake routine monitoring of PM2.5 composition at background stations. The AQD states for PM2.5 speciation this should include at least: nitrate NO3−, sulfate SO42−, chloride (Cl⁻), ammonium (NH4⁺), sodium (Na⁺), potassium (K⁺), magnesium (Mg²⁺), calcium (Ca²⁺), el...

To fight against the first wave of coronavirus disease 2019 (COVID-19) in 2020, lockdown measures were implemented in most European countries. These lockdowns had well-documented effects on human mobility. We assessed the impact of the lockdown implementation and relaxation on air pollution by comparing daily particulate matter (PM), nitrogen dioxi...

This study aims to picture the phenomenology of urban ambient total lung deposited surface area (LDSA) (including head/throat (HA), tracheobronchial (TB), and alveolar (ALV) regions) based on multiple path particle dosimetry (MPPD) model during 2017-2019 period collected from urban background (UB, n = 15), traffic (TR, n = 6), suburban background (...

This study analyzed the variability of equivalent black carbon (eBC) mass concentrations and their sources in urban Europe to provide insights into the use of eBC as an advanced air quality (AQ) parameter for AQ standards. This study compiled eBC mass concentration datasets covering the period between 2006 to 2022 from 50 measurement stations, incl...

This study presents the first long-term online measurements of submicron (PM1) particles at the ATOLL (ATmospheric Observations in liLLe) platform, in northern France. The ongoing measurements using an Aerosol Chemical Speciation Monitor (ACSM) started at the end of 2016 and the analysis presented here spans through December 2020. At this site, the...

To fight against the first wave of Coronavirus disease 2019 (COVID-19) in 2020, lockdown measures were implemented in most European countries. These lockdowns had well-documented effects on human mobility. We assessed the impact of the lockdown implementation and relaxation on air pollution by comparing daily particulate matter (PM), nitrogen dioxi...

A growing portion of scientists realises the need to not only alert about climate change, but also change their professional practices. A range of tools have emerged to promote more sustainable activities, yet many scientists struggle to go beyond simple awareness-raising to create concrete transition actions. Here we propose a game-based transitio...

Formation of ultrafine particles (UFPs) in the urban atmosphere is expected to be less favored than in the rural atmosphere due to the high existing particle surface area acting as a sink for newly formed particles. Despite large condensation sink (CS) values, previous comparative studies between rural and urban sites reported higher frequency of n...

The uptake of acetic acid (AcA) on natural Gobi dust is studied at room temperature and in the relative humidity range (<0.01–95% RH) using zero air as bath gas. The experiments were carried out in a U-shaped reactor coupled to a Selected-Ion Flow-Tube Mass Spectrometer (SIFT-MS) for gas-phase monitoring. The initial uptake coefficient, γ0, of AcA...

Particulate matter (PM) has become a major concern in terms of human health and climate impact. In particular, the source apportionment (SA) of organic aerosols (OA) present in submicron particles (PM1) has gained relevance as an atmospheric research field due to the diversity and complexity of its primary sources and secondary formation processes....

Aerosols influence the Earth’s climate directly through scattering and absorption of solar radiation and indirectly by affecting cloud properties. Here, observations were enriched by integration with hourly 72h Hysplit back-trajectories and the latest version of the EDGAR (Emissions database for Global Atmospheric Research) emission inventory, desc...

Formation of Ultrafine particles (UFPs) in the urban atmosphere is expected to be less favored than in the rural atmosphere due to the high existing particle surface area acting as a sink for newly-formed particles Despite the large condensation sink (CS) values, previous comparative studies between rural and urban site reported higher frequency of...

Particulate Matter (PM) has become a major concern in terms of human health and climate impact. In particular, the source apportionment (SA) of organic aerosols (OA) present in submicron particles (PM1) has gained relevance as an atmospheric research field due to the diversity and complexity of its primary sources and secondary formation processes....

Accurate knowledge of the physical, chemical and optical properties of aerosol particles is essential to reduce current uncertainties associated to their radiative impacts on Earth’s climate. However, the wide range of particle sources and complex (trans)formation processes they undergo lead to strong spatial and temporal variability of these. The...

Seasonal variability of non-refractory PM1 (NR-PM1) was studied at a rural background site (National Atmospheric Observatory Košetice – NAOK) in the Czech Republic to investigate the effect of regional and long-range atmospheric transport in central Europe. NR-PM1 measurements were performed by compact time-of-flight aerosol mass spectrometry (C-To...

Seasonal variability of non-refractory PM1 (NR-PM1) was studied at a rural background site (National Atmospheric Observatory Košetice – NAOK) in the Czech Republic to investigate the effect of regional and long-range atmospheric transport in central Europe. NR-PM1 measurements were performed by compact time-of-flight aerosol mass spectrometry (C-To...

Organic aerosol (OA) is a key component to total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectr...

The indoor environment is usually more polluted than outdoors due to emissions of gas and particle-phase pollutants from multiple sources, leading to their accumulation on top of the infiltration of outdoor pollution. While it is widely recognized that negative health effects arise from the exposure to outdoor air pollution, exposure to indoor poll...

Organic aerosol (OA) is a key component to total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectr...

Aerosolized black carbon is monitored worldwide to quantify its impact on air quality and climate. Given its importance, measurements of black carbon mass concentrations must be conducted with instruments operating in quality-checked and ensured conditions to generate data which are reliable and comparable temporally and geographically. In this stu...

Similarities and differences in the submicron atmospheric aerosol chemical composition are analyzed from a unique set of measurements performed at 21 sites across Europe for at least one year. These sites are located between 35 and 62°N and 10° W – 26°E, and represent various types of settings (remote, coastal, rural, industrial, urban). Measuremen...

The CARA program has been running since 2008 by the French reference laboratory for air quality monitoring (LCSQA) and the regional monitoring networks, to gain better knowledge—at a national level—on particulate matter (PM) chemistry and its diverse origins in urban environments. It results in strong collaborations with international-level academi...

Industrial metalworking facilities emit a variety of air toxics including volatile organic compounds, polycyclic aromatic hydrocarbons (PAHs) and heavy metals. In order to investigate these emissions, a 1-month multi-instrument field campaign was undertaken at an industrial site in Grande-Synthe, Dunkirk (France), in May and June 2012. One of the m...

The CARA program has been developed since 2008 by the French reference laboratory for air quality monitoring (LCSQA) and the regional monitoring networks to gain a better knowledge at the national level on the particulate matter (PM) chemistry and its diverse origins in urban environments. It results of strong collaborations with international-leve...

Near real-time measurements of submicron particulate matter (PM1) were carried out at an industrial and coastal site in Dunkirk (Northern France) over a 14-month period (July 2013–September 2014). This site is surrounded by various industrial plants (metallurgy, petrochemistry, food processing, power plant, etc.) and is characterized by intense shi...

It is now well recognized that Particulate Matter (PM) is one of the main air pollutants affecting both ambient and indoor air quality. While ambient PM mass concentration measurements are often performed by air quality monitoring networks, current regulations do not address their indoor concentrations. The latter can be estimated nonetheless from...

The electronic cigarettes (e-cigs) and more recently the heated tobacco products (HTP) provide alternatives for smokers as they are generally perceived to be less harmful than conventional cigarettes. However, it is crucial to compare the health risks of these different emergent devices, in order to determine which product should be preferred to su...

Here we report results of a detailed analysis of the urban and non-urban contributions to particulate matter (PM) concentrations and source contributions in five European cities, namely Schiedam (the Netherlands, NL), Lens (France, FR), Leipzig (Germany, DE), Zurich (Switzerland, CH) and Barcelona (Spain, ES). PM chemically speciated data from 12 E...

Volcanic sulfate aerosols play a key role in air quality and climate. However, the rate of oxidation of sulfur dioxide (SO2) precursor gas to sulfate aerosols (SO42-) in volcanic plumes is poorly known, especially in the troposphere. Here we determine the chemical speciation as well as the intensity and temporal persistence of the impact on air qua...

In this study, the performance of two types of source apportionment models was evaluated by assessing the results provided by 40 different groups in the framework of an intercomparison organised by FAIRMODE WG3 (Forum for air quality modelling in Europe, Working Group 3). The evaluation was based on two performance indicators: z-scores and the root...

The primary sugar compounds (SCs, defined as glucose, arabitol, and mannitol) are widely recognized as suitable molecular markers to characterize and apportion primary biogenic organic aerosol emission sources. This work improves our understanding of the spatial behavior and distribution of these chemical species and evidences their major effective...

We report here results of a detailed analysis of the urban and non-urban contributions to PM concentrations and source contributions in 5 European cities, namely: Shiedam (The Netherlands; NL), Lens (France; FR), Leipzig (Germany; DE), Zurich (Switzerland; CH) and Barcelona (Spain; ES). PM chemically speciated data from 12 European paired monitorin...

The knowledge of the underlying mechanisms by which particulate matter (PM) exerts its health effects is still incomplete since it may trigger various symptoms as some persons may be more susceptible than others. Detailed studies realized in more relevant in vitro models are highly needed. Healthy normal human bronchial epithelial (NHBE), asthma-di...

The primary sugar compounds (SC, defined as glucose, arabitol and mannitol) are widely recognized as suitable molecular markers to characterize and apportion primary biogenic organic aerosol emission sources. This work improves our understanding of the spatial behavior and distribution of these chemical species and evidences their major effective e...

Exposure to particulate matter (PM) is leading to various respiratory health outcomes. Compared to coarse and fine particles, less is known about the effects of chronic exposure to ultrafine particles, despite their higher number and reactivity. In the present study, we performed a time-course experiment in mice to better analyze the lung impact of...

Volcanic sulfate aerosols play a key role on air quality and climate. However, the oxidation of sulfur dioxide (SO2) precursor gas to sulfate aerosols (SO42−) in volcanic clouds is poorly known, especially in the troposphere. Here we determine the chemical speciation, lifetime and impact on air quality of sulfate aerosols from the 2014–15 Holuhraun...

A growing number of studies are using specific primary sugar species, such as sugar alcohols or primary saccharides, as marker compounds to characterize and apportion primary biogenic organic aerosols (PBOAs) in the atmosphere. To better understand their annual cycles, as well as their spatiotemporal abundance in terms of concentrations and sources...

In a context where a significant fraction of the population lives near industrial areas, the main objectives of this study are to provide (a) new data on PM2.5 chemical compositions, heavy-metal concentrations and trace gases released by metalworking activities and (b) new information on the near-field evolution (up to about a thousand meters) of s...

Atmospheric pollution is a striking regional issue for public health and ecosystems and has major global impacts on climate. Particulate matter (PM) can be of primary or secondary origin and its sources, both natural and anthropogenic, are very heterogeneous in space and time. Hence, many efforts have been made worldwide to get a better knowledge o...

The growth of small valeric and glutaric acid aerosol particles from 20 to 500 molecules has been studied at room temperature using classical molecular dynamics simulations. Due to a higher propensity to form hydrogen bonds, glutaric acids aggregates are shown to be denser than their valeric counterpart. Addition of water molecules with water: acid...

During the first Intensive Observation Period (IOP1) of the SHADOW (SaHAran Dust Over West Africa) campaign carried out during March–June 2015, the Mbour site (Senegal) was reinforced with a large setup of in-situ and remote sensing instruments to measure the aerosol optical, physical and chemical properties as well as the atmospheric dynamical fea...

A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed during wintertime (5 February to 15 March 2016) at a suburban site in Douai, northern France, in order to investigate the characteristics and sources of the organic matter (OM). The campaign average concentration of non-refractory submicron particulate matter (NR-P...

Measurements of inorganic precursor gases (NO, NO2, HONO, NH3, SO2 and HCl) and PM2.5 inorganic water-soluble ions (NO3⁻, SO4²⁻, NH4⁺, Cl⁻, Na⁺, Mg²⁺, Ca²⁺, K⁺) were performed at a suburban site in northern France for the first time using a MARGA 1S with an hourly time-resolution from August 2015 to July 2016. The observations were compared with ot...

A growing number of studies are using specific primary sugar species, such as sugar alcohols or primary saccharides, as marker compounds to characterize and apportion primary biogenic organic aerosols (PBOA) in the atmosphere. To better understand their annual cycles, as well as their spatio-temporal abundance in terms of concentrations and sources...

Trajectory-based statistical models (TMs) are widely used to locate source areas responsible for atmospheric pollution at receptor sites. In order to study the influence of long, medium and short-range back-trajectories (BTs) on geographical sources location, an original approach was applied to daily PM10 concentrations measured for 5 years (2009–2...

The adsorption properties of mineral dust toward organic molecules are poorly characterized so far. Heterogeneous processes between trace gases and mineral particles can affect the oxidative capacity of the atmosphere as well as constitute additional sources or sinks for these species. The current study investigates the adsorption efficiencies of n...

Particulate matter was sampled in Northern France during two summer and winter periods at both an urban background site (Douai, DO) and an industrialized coastal site (Grande-Synthe, GS). Ambient levels of particulate carbonaceous species and Polycyclic Aromatic Hydrocarbons (PAH) were measured by real-time measurements and via collection and analy...

Even though clinical, epidemiological and toxicological studies have progressively provided a better knowledge of the underlying mechanisms by which air pollution-derived particulate matter (PM) exerts its harmful health effects, further in vitro studies on relevant cell systems are still needed. Hence, aiming of getting closer to the human in vivo...

Ozone (O3) is an important atmospheric compound. As a strongly oxidizing species, tropospheric O3 can damage the health of living beings. During its journey in the lower layer of the atmosphere, ozone can encounter dust particles lifted by winds, storm events or farming activities. Observations have shown that Saharan dust events were negatively co...

The present study offers the first chemical characterization of the submicron (PM1) fraction in western Africa at a high time resolution, thanks to collocated measurements of nonrefractory (NR) species with an Aerosol Chemical Speciation Monitor (ACSM), black carbon and iron concentrations derived from absorption coefficient measurements with a 7-w...

The heterogeneous interaction of isoprene with TiO2 surfaces was studied under dark and UV light irradiation conditions. The experiments were conducted at room temperature, using zero air as bath gas, in a flow reactor coupled with a SIFT-MS (selected-ion flow-tube mass spectrometer) and a FTIR spectrometer for the gas-phase monitoring of reactants...

According to the literature, tiny amounts of transition metals in airborne fine particles (PM2.5) may induce proinflammatory cell response through reactive oxygen species production. The solubility of particle-bound metals in physiological fluids, i.e. the metal bioaccessibility is driven by factors such as the solution chemical composition, the co...

Mineral dust is a major component of atmospheric aerosol that can impact both the climate and the oxidative capacity of the atmosphere. It has been recently suggested that heterogeneous processes on natural mineral dusts can act as a sink of Volatile Organic Compounds (VOCs) and possibly as a sources of oxygenated VOCs (OVOCs). More precisely, lite...