A large part of France has been suffering for several days from an episode of air pollution with fine particles, in particular PM10, particles with a diameter of less than 10 micrometers. On Wednesday February 15, the alert thresholds were triggered in Cher, Indre-et-Loire and Loiret, thus announced the various prefectures of the Center-Val de Loire.
The phenomenon continues in other territories, such as Ile-de-France. In the South, due to a fourth day of persistence of the information and recommendation threshold, the departments of Vaucluse and Bouches-du-Rhône are on alert level 2 (PM10 pollution).
What are the causes of this winter episode?
Particularly strong air pollutant emissions at the moment are linked to “a conjunction of elements” both structural and cyclical, explains Airparif. They result both from emissions from road traffic, in particular from combustion engine vehicles producing nitrogen oxide (NOx) and fine particles.
The other cause comes from residential heating, particularly with wood, knowing that the older the appliances, the more particles they emit, underlines Antoine Trouche, engineer at Airparif.
These recurring elements in certain cities are aggravated by specific meteorological phenomena: on the one hand low temperatures until recent days which favored the increased use of heating appliances and on the other “a well-established anticyclonic situation generating a weak dispersion of air masses” and therefore little wind preventing the dissipation of pollutants, underline Airparif and Prev’air.
What consequences for health?
Exposure to pollution peaks can result in respiratory discomfort or infections and an increase in hospitalizations or mortality linked to these pathologies, particularly among vulnerable people (pregnant women, infants, people over 65 or suffering from asthma…) or sensitive (diabetics, immunocompromised people…).
In the longer term, fine particle pollution caused 238,000 premature deaths in the European Union in 2020, according to a report by the European Environment Agency published at the end of November.
What measures to fight against fine particles?
The measures taken by the authorities concern in particular road traffic in several agglomerations, for example the territory of Grand Avignon. In Marseille, differentiated traffic has been imposed since 8 a.m. on Wednesday February 15. It limits access to the hyper-city center and the bordering districts of the coast to electric vehicles and those with a Crit’Air sticker ranging from 1 to 3, declares the prefecture of Bouches-du-Rhône. Other restrictions relate to vehicles transporting goods, that of ships inside and near the basins.
In addition, in several departments, the maximum speed authorized on the road is lowered by 20 km/h (without going below 70 km/h). This is the case in the Bouches-du-Rhône, the Var or the Alpes-Maritimes. In the Cher, the “maximum authorized speed on 2 × 2 lanes is lowered by 20 km/h, without however falling below 90 km/h”specifies the prefecture.
Depending on the territory, other measures are taken, such as the ban on burning green waste in the open air or the use of individual wood heating.