The arrival of fine weather promotes the dispersal of pollen, a dynamic that has been accelerating for several years with the rise in temperatures induced by global warming.
With 28°C this Wednesday in Biarritz, spring or even summer temperatures began to be recorded in France this week. A marker of the ever earlier arrival of heat in France, but which also promotes the release of pollen.
“The weather is spring-like this week and the pollens are out,” note on his site the National Aerobiological Surveillance Network (RNSA). The organization has updated its pollen allergy risk map, which confirms this dynamic.
All the departments of metropolitan France are at least in “medium” health impact, with 15 departments in “high” impact. Among these are the Lower Rhinethe Territory of Belfortthe Haute-SaoneTHE Alpes-Maritimesthe WasTHE Bouches-du-Rhonethe Vauclusethe Gard, Herault, Aveyronthe Tarnthe Upper Garonne, Ariege, the Aude and the Eastern Pyrenees.
Different types of pollen implicated
From north to south of France, the types of pollen involved differ. In Alsace, those of birch, hornbeam and ash are the most present. In Haute-Saône and in the Territoire de Belfort, those of charm.
In the departments of the south of France, it is mainly the pollens of cupressaceae, which notably include juniper and cypress, which are singled out.
For allergy sufferers, the gradual arrival of birch pollen on the territory is in any case bad news. The RNSA evokes a “risk of allergy which will evolve between the low level and the high level according to the departments”.
And Press release of the RNSA already warned on March 21 regarding birch pollen. The season “will start this week” alerted the network, which specified that the flowering of gasoline began on March 27 in Paris or Montluçon.
“Birch pollen has a very high allergenic potential causing allergy sufferers to many ocular, nasal and even respiratory symptoms”, continues the RNSA.
A short lull
The significant sunshine experienced by France on Wednesday and Thursday promotes the release of pollen into the air. Coupled with air pollution, symptoms in people can even be exacerbated.
The arrival of the rain from this Thursday will nevertheless give a moment of respite to sensitive people. Modeling maps of France’s exposure to birch pollen show that from March 31, a lull in the spread is expected.
But that’s without counting on their strong comeback from April 2, before reaching a peak on April 4. A large part of the country will be subject to a large concentration of birch pollen.
The role of global warming
A note published on February 24 on the website of the Ministry of Ecological Transition entitled “Impact of climate change: health and society”, shows that global warming and the rise in temperatures it induces has a link with the quantity of pollen released into the air every year.
“The amounts of birch pollen that are released in March-April depend on the temperatures and the weather before from July of the previous year,” the note says.
With a historically hot summer of 2022, the quantities of pollen released this year will therefore be logically significant. “This change in temperature has only led to an increase in the amount of birch pollen emitted and therefore an increase in allergies,” said the ministry.
