The greatest air quality experiment ever: Policy suggestions from the COVID-19 lockdown in twelve European cities

COVID-19 (Coronavirus disease 2019) hit Europe in January 2020. By March, Europe was the active centre of the pandemic. As a result, widespread "lockdown" measures were enforced across the various European countries, even if to a different extent. Such actions caused a dramatic reduction, especially in road traffic. This event can be considered the most significant experiment ever conducted in Europe to assess the impact of a massive switch-off of atmospheric pollutant sources. In this study, we focus on in situ concentration data of the main atmospheric pollutants measured in twelve European cities, characterized by different climatology, emission sources, and strengths. We propose a methodology for the fair comparison of the impact of lockdown measures considering the non-stationarity of meteorological conditions and emissions, which are progressively declining due to the adoption of stricter air quality measures. The analysis of these unmatched circumstances allowed us to estimate the impact of a nearly zero-emission urban transport scenario on air quality in 12 European cities. The clearest result, common to all the cities, is that a dramatic traffic reduction effectively reduces NO2 concentrations. In contrast, each city’s PM and ozone concentrations can respond differently to the same type of emission reduction measure. From the policy point of view, these findings suggest that measures targeting urban traffic alone may not be the only effective option for improving air quality in cities.Peer ReviewedArticle signat per 19 autors/es: Marialuisa Volta 1, Umberto Giostra 2, Giorgio Guariso 3, Jose Baldasano 4, Martin Lutz 5, Andreas Kerschbaumer 5, Annette Rauterberg-Wulff 5, Francisco Ferreira 6, Luısa Mendes 6, Joana Monjardino 6, Nicolas Moussiopοulos 7, Christos Vlachokostas 7, Peter Viaene 8, Janssen Stijn 8, Enrico Turrini 1, Elena De Angelis 1, Claudio Carnevale 1, Martin L. Williams 9, Michela Maione 2,10 // 1 Dipartimento di Ingegneria Meccanica e Civile, Università di Brescia, Brescia, Italy; 2 Dipartimento di Scienze Pure e Applicate, Università di Urbino Carlo Bo, Urbino, Italy; 3 Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy; 4 Centro Nacional de Supercomputación, Universitat Politècnica de Catalunya, Barcelona, Spain; 5 Senatsverwaltung für Umwelt, Mobilität, Verbraucher-und Klimaschutz, Berlin, Germany; 6 Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciencias e Tecnologia Universidade Nova de Lisboa, Caparica, Portugal; 7 Aristoteleio Panepistemio Thessalonikes, Thessalonike, Greece; 8 VITO, Vision on Technology, Mol, Belgium; 9 Environmental Research Group, Imperial College, London, United Kingdom; 10 Istituto di Scienze dell’Atmosfera e del Clima, Consiglio Nazionale delle Ricerche, Bologna, ItalyPostprint (published version

Experimental studies about the impact of traction sand on urban road dust composition

http://www.elsevier.com/locate/issn/00489697Traffic causes enhanced PM10 resuspension especially during spring in the US, Japan, Norway, Sweden and Finland, among other countries. The springtime PM10 consists primarily of mineral matter from tyre-induced paved road surface wear and traction sand. In some countries, the majority of vehicles are equipped with studded tyres to enhance traction, which additionally increases road surface wear. Because the traction sand and the mineral matter from the pavement aggregate can have a similar mineralogical composition, it has been difficult to determine the source of the mineral fraction in the PM10. In this study, homogenous traction sand and pavement aggregate with different mineralogical compositions were chosen to determine the sources of PM10 particles by single particle analysis (SEMyEDX). This study was conducted in a test facility, which made it possible to rule out dust contributions from other sources. The ambient PM10 concentrations were higher when traction sand was used, regardless of whether the tyres were studded or not. Surprisingly, the use of traction sand greatly increased the number of the particles originating from the pavement. It was concluded that sand must contribute to pavement wear. This phenomenon is called the sandpaper effect. An understanding of this is important to reduce harmful effects of springtime road dust in practical winter maintenance of urban roads

The greatest air quality experiment ever: Policy suggestions from the COVID-19 lockdown in twelve European cities

COVID-19 (Coronavirus disease 2019) hit Europe in January 2020. By March, Europe was the active centre of the pandemic. As a result, widespread "lockdown" measures were enforced across the various European countries, even if to a different extent. Such actions caused a dramatic reduction, especially in road traffic. This event can be considered the most significant experiment ever conducted in Europe to assess the impact of a massive switch-off of atmospheric pollutant sources. In this study, we focus on in situ concentration data of the main atmospheric pollutants measured in twelve European cities, characterized by different climatology, emission sources, and strengths. We propose a methodology for the fair comparison of the impact of lockdown measures considering the non-stationarity of meteorological conditions and emissions, which are progressively declining due to the adoption of stricter air quality measures. The analysis of these unmatched circumstances allowed us to estimate the impact of a nearly zero-emission urban transport scenario on air quality in 12 European cities. The clearest result, common to all the cities, is that a dramatic traffic reduction effectively reduces NO2 concentrations. In contrast, each city’s PM and ozone concentrations can respond differently to the same type of emission reduction measure. From the policy point of view, these findings suggest that measures targeting urban traffic alone may not be the only effective option for improving air quality in cities

Bestimmung der Real-Emissionen von Kraftfahrzeugen im Berliner Straßenverkehr

Um für die Fahrzeugflotte auf Berliner Straßen die Real-Emissionen besser beurteilen zu können, wurden erstmals im Herbst 2019 berührungslose Abgasmessungen an Fahrzeugen durchgeführt. Im Fokus standen dabei die Stickoxidemissionen. Für die Messung wurde das System OPUS RSD5000 verwendet. Zusätzlich wurden auch die Kennzeichen der vermessenen Fahrzeuge benutzt, um Fahrzeugkategorie, Antriebsart und Emissionsstandard zu bestimmen. Dieser Beitrag fasst die Ergebnisse für Pkw zusammen. Der Vergleich der NOx-Emissionen mit den Grenzwerten aus der Typzulassung ergab die bekannten Überschreitungen für Dieselfahrzeuge bis Euro 6ab. Die NOx-Emissionen der neusten Diesel-Pkw mit Euro 6d-temp und 6d waren im Mittel grenzwertkonform, jedoch lagen immer noch etwa 25 % dieser Fahrzeuge oberhalb des Grenzwertes inklusive Konformitätsfaktor. Die mit RSD bestimmten Emissionsfaktoren zeigten im Mittel eine gute Übereinstimmung mit den für die vermessenen Fahrzustände repräsentativen Faktoren des HBEFA 4.1. Dabei sind die Einflüsse der Umgebungstemperatur und Laufleistung, wie im HBEFA angeboten, zu berücksichtigen