Changes

Lockdown and restrictions on mobility slowed down economic activity during the first wave of the COVID-19 pandemic and led to a significant drop in road transport, as outlined in other chapters. To analyse the effects of this slowdown on air pollution, the European Environment Agency (EEA) monitored the average weekly and monthly concentrations of nitrogen dioxide (NO2NO₂) and fine particles (PM 10 and PM 2.5), measured every hour or every day by nearly 3,000 gauging stations (EEA, 2020 and 2021). Exposure to air pollution may have adverse effects on health, and in particular people with respiratory diseases could be more vulnerable to COVID-19. Although the epidemiological research carried out to date is as yet inconclusive, all signs suggest that such exposure worsens the condition of people infected with coronavirus. What has been concluded is that a higher air quality prevented 2,190 early deaths in Europe ascribable to fine particles (PM 2.5) from 21 February to 17 May 2020 (Giani ''et al., '' 2020).

Data show that concentrations of NO2NO₂, which are primarily bred by road transport, decreased during lockdown. However, they do not suggest a consistent reduction in the concentration of PM 2.5 particles, probably due to the different origins of this pollutant, which include fuel for heating, industrial activity, traffic and reactions with other atmospheric pollutants, such as ammonia, which is related to the use of agricultural fertilisers. Weather conditions may also contribute to decreases or increases in the concentration of pollutants and explain, in part, why reductions in air pollution are rarely homogeneous.

The graphs show the evolution of atmospheric NO2 NO₂ pollution in ten European cities between weeks 11 and 27 in 2019 and 2020. In most cases, there was a significant reduction in micrograms per cubic metre (μg / m3m³), which was especially remarkable in cities such as Paris (weeks 13 and 16), Milan/Milano (week 13) and Madrid (week 15).