While motorists lost patience in monster traffic jams at the gates of the capital this Sunday, September 17, the residents of the roads were able to breathe a few hours. The Paris car-free day, organized for the ninth time from 11 a.m. to 18 p.m., reduced the concentration of nitrogen dioxide (NO2) by 5% to 20% around traffic axes compared to a normal Sunday, says Airparif, the association approved by the State for the measurement of air quality in Greater Paris. this Monday. "A decrease of the same order of magnitude as that observed during the 2022 and 2021 editions.»
The improvement in air quality has not been restricted to areas in which circulation has been restricted, notes Airparif, since decreases in nitrogen dioxide concentrations of 5% to 10% have also been observed along the ring road. This temporary ban on vehicles has also allowed, to a lesser extent, "slight decreases in particle concentrations" along traffic routes.
The concentration of nitrogen dioxide (NO2) decreased this Sunday around the roads. AirParif
Nitrogen dioxide, harmful to health
It is at Opera, in the heart of Paris, that the drop in NO2 concentration has been the most important, according to Airparif. On the maps shared by the institute, there is also a significant drop along the A4 near the capital, but also on the quai de Bercy and the national 3, in Pantin, which also participated in the event.
NO2, a pollutant of which road transport is, with industry, one of the main emitters, is an irritating gas harmful to health, penetrating "into the finest ramifications of the respiratory tract," recalls Ademe. It is "40 times more toxic than carbon monoxide." Its concentration in the Parisian air has further decreased in 2022, says Airparif, but some busy roads remain above the annual limit limit of 40 μg/m3 on average, itself higher than the recommendations of the World Health Organization (10 μg/m3).
The Paris Car Free Day is organized every year by the town hall, closing the capital to motorized vehicles, with exceptions. A way to improve air quality for a few hours, but also to push the vision of the majority of streets relieved of their car traffic so that pedestrians can reclaim them. The neighboring towns of Pantin, Les Lilas and Pré-Saint-Gervais joined the event on Sunday. In parallel, the city center and the Champs-Élysées are pedestrianized on the first Sunday of the month, and some neighborhoods are pedestrianized every Sunday.