September 2021 pollen map: 4 departments on red alert for ragweed

“ Ragweed pollens will still be present in the air with a very high risk of allergy in Ain, northern Isère, Ardèche and Drôme and a high risk in the Rhône, Loire, Saône et Loire, Charente, Nièvre, and Gard“announcement the allergo-pollen bulletin September 17. The risk of allergy will be low to medium in the departments around this main infestation area that is the Rhône valley. (see map below). BHowever, there is news for allergy sufferers: the concentrations of ragweed pollen are starting to drop slightly and the end of the season is slowly but surely approaching.

>> Regarding other pollens (grasses, urticaceae, sagebrush, plantains), we are at the end of the season with low concentrations and an allergy risk that will not exceed the low or very low level.

Ambrosia: it colonizes more and more territories

Pollen map for September 17, 2021.

Today, a large part of France is affected by ragweed pollen, notably the Rhône-Alpes region, Burgundy, Pays de la Loire, Alsace and Poitou-Charentes. With the systematic use of machinery in agriculture and public works thousands of cubic meters of soil containing ragweed seeds are moved from one place to another, which has gradually allowed this very allergenic plant to colonize new territories. And the number of allergic people increases every summer: “it is estimated that 6 to 12% of the population of the affected areas is allergic” our association Stop Ambrosia.

>> To avoid its proliferation, report ragweed plants if you spot any: www.signalement-ambroisie.fr

Pollens: the calendar

April / May: beware of plane trees and cypresses (high risk), as well as birch, willow, beech and hornbeam (medium risk)
May / June: watch out for the olive tree (medium risk)
May / August: beware of grasses (high to very high risk)
August / September: watch out for ambrosia

After the salutary winter break, the pollen season resumes in February / March with alder, birch, ash and cypress pollens (high risks) as well as poplar (medium risk)

To note : The National Aerobiological Surveillance Network makes available on its site a information guide on the main pollens spring allergens, in town and in the countryside.

More aggressive pollens because of pollution

“There is a synergy between the increase in diesel particles and the increase in IgE allergy antibodies to pollen “, explains to Top Santé (April 2020), Professor Frédéric de Blay, pulmonologist. The increase in CO2 in the atmosphere stimulates the production of pollen by plants, worsening the symptoms of people with allergic rhinitis or asthma. “With pollution (nitrogen oxide, ozone, particles, etc.), the plant produces more pollens, we adds Nicolas Viovy, researcher at the Climate and Environmental Sciences Laboratory. Pollution damages the envelope of pollens, which then release their allergenic proteins into the air. “

In addition, pollution irritates the mucous membranes which normally filter allergens and all inhaled substances, it weakens the epithelial barriers (mucous membranes of the nose, eyes, skin, etc.), which allows allergens, chemicals, molds to penetrate more easily to the bronchi. As a result, people are more sensitive with lower amounts of pollen.

Main responsible: fine particles emitted by combustion of heaters, road transport (diesel and gasoline). Up to 800 times smaller than a hair, these particles would promote allergies to pollen “by lowering the threshold of bronchial reactivity and / or by accentuating the irritation of the nasal or ocular mucous membranes in sensitized subjects”, indicates the National Agency for Food, Environmental and Occupational Health Safety (ANSES). A study carried out in the capital has also shown that each episode of fine particle pollution leads to a significant increase in emergency room consultations for an exacerbation of asthma.

What is grass pollen?

Grasses include nearly 10,000 species (including timothy, cocksfoot, fescue, ryegrass, bluegrass, black grass, quackgrass, rye, wheat, corn, barley, oats, etc.) and are the main triggering factors hay fever in people with allergies. It is considered that 70% of people allergic to pollens are sensitive to grass pollens.

Grasses are wind pollinated (what scientists call wind pollination). As this pollination is much less targeted than during pollination by an insect, plants with anemophilous pollination compensate for this lack by producing large quantities of pollen. For example, an average stalk of rye produces roughly 7 million pollen grains.

However, it only takes a few grains of grass pollen in the air for the symptoms appear in people with allergies. They must therefore anticipate their allergy and start their treatment properly now.

Note that whenwe are allergic to pollen of grasses, there is a risk of cross-allergy with peanuts, wheat flour, melon, potatoes, peppers and tomatoes.

Practical advice for allergy sufferers

It is high time to take some precautions if you are allergic to grass pollen and to start treatment. In addition to taking your antihistamine treatment, consult a doctor or an allergist in the event of symptoms, regularly check the risks of allergy on our website to adapt your treatment.

When preparing your meals, think about foods that have a natural antihistamine effect
Rinse your hair at night when you get home.
Ventilate at least 10 minutes per day before sunrise and after sunset.
Do not dry your laundry outside.
Do not drive with the window open.
Avoid sports activities outside even if with the deconfinement the desire to escape is great!
Wear a mask with sunglasses and a hat.
Follow your treatment and do not hesitate to consult a doctor or an allergist in case of symptoms.

Remember to clean your nose well: “This eliminates the allergens that clog the nasal passages “, indicates Thierry Folliard, naturopath. Several techniques exist. You are free to choose the one that seems easiest to achieve.

The easiest way : as for babies, specialists recommend tilting the head to one side, inserting a pipette of physiological saline into the upper nostril, pressing strongly. The secretions will come out through the opposite nostril. Repeat the gesture on the other side.
The sweetest way: use an “isotonic” seawater spray. This solution turns out to be gentler, but less effective than the first technique.
The most “naturo” way : “buy a small watering can in a wellness boutique, add a tablespoon of Guérande salt and a teaspoon of magnesium chloride before dissolving in water.” Lean forward, turn your head to one side, hold your breath, pour the mixture into the nostril. The flow should be through the other nostril. Change sides and repeat the operation.

Source:National Aerobiological Surveillance Network (RNSA)

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