Generally, in spring and summer, the rain is eagerly awaited by those allergic to pollen because it causes a decrease in symptoms. However, if light to moderate rains effectively flatten pollen on the ground and push plants to keep their pollen, paradoxically, thunderstorms can cause the opposite effect.
This weekend, Île-de-France hospitals saw their number of consultations for asthma attacks increase tenfold, reports France Bleu.
“We were very surprised”
Almost all of metropolitan France is currently classified as red, ie the risk of allergies to grass pollen is high. However, this situation has been going on for several weeks: the reason for the recent spike in asthma attacks is thunderstorms.
“We were very surprised,” Maxime Gauthier, head of emergency at the Simone Veil hospital in Eaubonne (Val d’Oise), confesses to BFM Paris-Île-de-France.
The phenomenon has already been observed in the United Kingdom or even in Australia where, in 2016 in Melbourne, ten people died due to respiratory difficulties. Hospitals experienced a 992% increase in asthma admissions within 30 hours of the onset of thunderstorms, according to a study published by the lancet. “In most cases, those affected during these episodes had no known history of asthma,” says Public Health France.
This storm asthmaor storm asthma in French, was also studied in Nantes, in June 2023, where 152 emergency calls for asthma attacks had been received compared to only 27 in the four days prior to the passage of the rainy front.
From small particles to the bronchi
Storms cause the fragmentation of pollen, which becomes finer and smaller and therefore more numerous in the air. These particles are then dispersed by the storm’s wind gusts.
“These pollens are absorbed by clouds in the atmosphere, mix with water and are electrified by lightning, then break into very small particles and vaporize as an aerosol,” explains Maxime Gauthier.
In addition, as detailed by Public Health France, this “micronization of pollen grains (…) allows deeper penetration into the respiratory tree.” Usually, the pollens remain fixed at the level of the eyes or at the height, causing rhinitis, for example. Here they can progress to the bronchi and cause asthma.
Climate change
Although this phenomenon remains rare in France, Public Health France advises people who are allergic to pollen to stay indoors with the windows closed when a storm approaches during periods of pollen emission.
As more and more people are affected by these allergies, whether due to pollution, climate change or our lifestyle, the issue of asthma from storms could become a concern given the increase in extreme weather events, including storms, also linked to climate change.
Source: BFM TV
