Impact of 2020 COVID-19 lockdowns on particulate air pollution across Europe
<p>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...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/10145/2023/acp-23-10145-2023.pdf |
| Summary: | <p>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 dioxide
(<span class="inline-formula">NO<sub>2</sub></span>) and ozone (<span class="inline-formula">O<sub>3</sub></span>) concentrations, as well as particle number
size<span id="page10146"/> distributions (PNSDs) and particle light absorption coefficient in situ
measurement data, with values that would have been expected if no COVID-19 epidemic had occurred
at 28 sites across Europe for the period 17 February–31 May 2020.
Expected PM, <span class="inline-formula">NO<sub>2</sub></span> and <span class="inline-formula">O<sub>3</sub></span> concentrations were calculated from the
2020 Copernicus Atmosphere Monitoring Service (CAMS) ensemble forecasts,
combined with 2019 CAMS ensemble forecasts and measurement data. On average,
lockdown implementations did not lead to a decrease in PM<span class="inline-formula"><sub>2.5</sub></span> mass
concentrations at urban sites, while relaxations resulted in a <span class="inline-formula">+</span>26 <span class="inline-formula">±</span> 21 % rebound. The impacts of lockdown implementation and relaxation on
<span class="inline-formula">NO<sub>2</sub></span> concentrations were more consistent (<span class="inline-formula">−</span>29 <span class="inline-formula">±</span> 17 and <span class="inline-formula">+</span>31 <span class="inline-formula">±</span> 30 %, respectively). The implementation of the lockdown measures
also induced statistically significant increases in <span class="inline-formula">O<sub>3</sub></span> concentrations
at half of all sites (<span class="inline-formula">+</span>13 % on average). An enhanced oxidising capacity
of the atmosphere could have boosted the production of secondary aerosol at
those places. By comparison with 2017–2019 measurement data, a
significant change in the relative contributions of wood and fossil fuel
burning to the concentration of black carbon during the lockdown was
detected at 7 out of 14 sites. The contribution of particles smaller than 70 nm to the total number of particles significantly also changed at most of
the urban sites, with a mean decrease of <span class="inline-formula">−</span>7 <span class="inline-formula">±</span> 5 % coinciding with
the lockdown implementation. Our study shows that the response of PM<span class="inline-formula"><sub>2.5</sub></span>
and PM<span class="inline-formula"><sub>10</sub></span> mass concentrations to lockdown measures was not systematic at
various sites across Europe for multiple reasons, the relationship between
road traffic intensity and particulate air pollution being more complex than
expected.</p> |
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| ISSN: | 1680-7316 1680-7324 |