COVID-19 lockdowns highlight a risk of increasing ozone pollution in European urban areas.

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From: Atmospheric Chemistry and Physics(Vol. 21, Issue 5)
Publisher: Copernicus GmbH
Document Type: Brief article
Length: 299 words

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Abstract :

In March 2020, non-pharmaceutical intervention measures in the form of lockdowns were applied across Europe to urgently reduce the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus which causes the COVID-19 disease. The aggressive curtailing of the European economy had widespread impacts on the atmospheric composition, particularly for nitrogen dioxide (NO.sub.2) and ozone (O.sub.3). To investigate these changes, we analyse data from 246 ambient air pollution monitoring sites in 102 urban areas and 34 countries in Europe between February and July 2020. Counterfactual, business-as-usual air quality time series are created using machine-learning models to account for natural weather variability. Across Europe, we estimate that NO.sub.2 concentrations were 34 % and 32 % lower than expected for respective traffic and urban background locations, whereas O.sub.3 was 30 % and 21 % higher (in the same respective environments) at the point of maximum restriction on mobility. To put the 2020 changes into context, average NO.sub.2 trends since 2010 were calculated, and the changes experienced across European urban areas in 2020 was equivalent to 7.6 years of average NO.sub.2 reduction (or concentrations which might be anticipated in 2028). Despite NO.sub.2 concentrations decreasing by approximately a third, total oxidant (O.sub.x) changed little, suggesting that the reductions in NO.sub.2 were substituted by increases in O.sub.3 . The lockdown period demonstrated that the expected future reductions in NO.sub.2 in European urban areas are likely to lead to widespread increases in urban O.sub.3 pollution unless additional mitigation measures are introduced.

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Gale Document Number: GALE|A655465693