"PM10 particles come mainly from desert dust brought from the Sahara by southerly winds", explains the Atmo Nouvelle-Aquitaine agency.
This is the third time this phenomenon occurred in France in less than a month, after a first episode in early February and a second one last weekend.
Combined with good weather conditions (anticyclone and temperature inversion) and other sources of fine particle emissions such as domestic heating, road traffic, agricultural spraying, the phenomenon has generated significant pollution peaks in several regions, from Corsica to Ile-de-France via Burgundy, the Alps and the Grand Est region.
Air pollution alert
An air pollution alert was issued on Wednesday for two days in three departments in the south west: the Pyrénées-Atlantiques, the Landes and the Gironde.
Speed limits are reduced in these departments by 20km/h on all roads where motorists can usually travel at 90km/h or more. On roads where the speed limit is normally 80km/h, it has been lowered to 70km/h.
Quand les poussières de sable du Sahara recouvrent la France d’un voile de pollution https://t.co/Py0PV2Szas
— Le Monde Planète (@lemonde_planete) March 3, 2021
The Bas-Rhin in eastern France has also seen high levels of air pollution with "Saharan" particles and "combustion", according to the prefecture, which will implement several measures to counter the rise in PM10 pollutants and nitrogen dioxide, considered above recommended thresholds.
Among them, a reduction of 20 km/h of the speed "on the motorway network and roads with separate carriageways", without however "going below 70km/h," says the press release.
The Strasbourg Eurométropole announced free public transport on Thursday.
