Agricultural spraying was responsible for pollution peaks in Ile-de-France and the Grand-Est this weekend. A collective calls on the state to "drastically limit them."
This weekend, a first episode of spring pollution was observed in several points of the territory, especially in Ile-de-France and in the Grand-Est, the two regions most affected by the spread of the Covid epidemic- 19. Because, while the containment measures made it possible to reduce pollution linked to road traffic with a spectacular fall in nitrogen oxide emissions, they had no effect on the levels of fine particles, the most dangerous for health because they penetrate deep into the airways. These levels even increased during the week due to weather conditions (sunshine and absence of wind) to exceed, on Saturday March 28, the legal limits, in the Paris agglomeration, the Bas-Rhin or the Haut-Rhin.
In addition to residential wood heating, this episode of pollution is characterized by "a large proportion of secondary particles formed from ammonia and nitrogen oxides, ammonia being mainly derived from the spreading of fertilizers", recalls Atmo Grand -Is the organization responsible for monitoring air pollution in the region. The chemical process is well known: during agricultural spreading, ammonia gas (NH3), passing through the atmosphere, reacts with nitrogen oxides (NOx) - from road traffic or industrial activity - to form particles of ammonium nitrate and ammonium sulfate. These particles can travel for several kilometers, hence the pollution peaks observed in large cities, such as Paris, Strasbourg or Mulhouse.
The areas affected by these peaks are also those that pay the highest price for the coronavirus. In a note released on Friday, March 27, Atmo France, which brings together all of the air quality monitoring organizations, concludes that "chronic exposure to air pollution is an aggravating factor for health impacts during of contagion by Covid-19 ".