The impact of containment on air quality in the Paris region.
Provisional Assessment: Week of March 16-20, 2020
Average maps of nitrogen dioxide pollution from 17 to 19 March 2020: in normal, containment and difference situations.
On the other hand, little impact was observed for particulate matter, which came more from sources where the decrease in traffic did not compensate for the increase due to residential heating and continued agricultural activities, combined with favourable spring weather conditions for particulate matter observed in several neighbouring regions. In fact, air quality was not as good as expected on Wednesday 18 March. However, with the strong decrease in traffic, levels did not increase to the point of placing us in a pollution episode, which would probably have been the case under normal conditions with similar conditions and normal traffic.
The change in weather conditions from Saturday 21 March, combined with the very substantial drop in emissions, particularly from air and road traffic, leads to "good" air quality in this second week of confinement. These weather conditions typical of this period of the year may nevertheless be very likely to recur.
You will find in the PDF below a summary of the impacts on the quantity of pollutants released into the atmosphere and on the quality of the air breathed by the inhabitants of the Paris region