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Pollen allergies linked to pollution

Runny or stuffy nose, itchy eyes and throat... pollen allergies are more and more frequent. Pollution is one of the major causes:gases and polluting particles modify the pollen and irritate the mucous membranes. Nasal and ocular hygiene washes away the pollutants and pollens accumulated on the mucous membranes during the day.

Pollen allergy is gaining ground

In France and around the world, respiratory allergies affect more and more people, especially in industrialized countries. About 10% of French people suffer from pollen allergies, and more generally, 25% suffer from respiratory allergies. This proportion has doubled over the past 20 years. By way of comparison, Inserm estimates that today about 2% of adults and 5% of children suffer from a food allergy.

Allergy to pollen:the symptoms

The respiratory allergy to pollens is also nicknamed "hay fever" or seasonal rhinitis. It causes a series of more or less intense symptoms:

  • a rhinitis accompanied by sneezing :the nose is runny and itchy. Its inflamed mucous membrane may swell and the nose may become congested;
  • conjunctivitis :the protective membrane of the eye, or conjunctiva, becomes inflamed. She blushes and tingles, her eyes water;
  • an irritated throat possibly accompanied by coughing;
  • a fatigue .

All these signs are linked to an abnormal reaction of the immune system to the pollen in question. The body's defenses consider the pollen as foreign bodies against which it is necessary to fight, and trigger an inflammatory reaction. Histamine, an inflammatory mediator, is released en masse during pollen allergy.

People sensitive to pollen allergies

A priori banal, seasonal rhinitis can be complicated by chronic sinusitis or even asthma. People with respiratory failure, pregnant women, children and the elderly are most susceptible. Hay fever can also cause otitis media in children.

Certain hereditary genes predispose to the occurrence of pollen allergies during life.

You can consult the allergo-pollinic bulletin of the RNSA (National Aerobiological Surveillance Network).

Pollution aggravates pollen allergies

Air pollution aggravates pollen allergies for two reasons. While some polluting particles modify the structure of pollens which become more aggressive, pollution weakens our mucous membranes.

Pollen modified by pollution

As indicated in the opinion of the environment agency Anses on exposure to pollen, certain chemical pollutants such as ozone (O3), sulfur dioxide (SO2) or nitrogen dioxide ( NO2) deform and fracture the wall of pollen grains . The fragments have a very high allergenic potential since their size is 4 to 80 times smaller than the initial pollen grain. They thus penetrate much deeper into the respiratory tract.

Chemical pollutants are even capable of modifying the protein structure of pollens, so that some become more allergenic.

Finally, pollen can attach themselves to certain fine polluting particles such as soot carbon, which could increase their allergenic power.

Mucous membranes weakened by pollution

fine particles inhaled in the ambient air irritate the respiratory and ocular mucous membranes. The airways are thus more sensitive and defend themselves less well. Access to pollen in the body is facilitated. The sensitivity of individuals to pollen is thus increased during pollution peaks.

In cities where there is little greenery, the urban population is still susceptible to allergies. This paradox can be explained simply:if plants emit allergens, they are also the best bulwark against pollution. In urban areas, green spaces well constituted allow:

  • filter many air pollutants thanks to the trees that absorb them, and to capture fine particles through the hairs, roughnesses and waxes on the surface of the leaves;
  • the decrease in temperature in cities thanks to the urban vegetation cover, which provides shade and humidity. The use of polluting air conditioning in summer is thus reduced.

Allergies to pollen:protect yourself first

Fighting allergies means first of all cleaning the mucous membranes of allergens, but also getting rid of pollutants accumulated over the day.

Cleansing and protective solutions

Nasal hygiene

Daily nose hygiene is essential if you are allergic to pollen. For a simple washing of the nasal mucous membranes, the isotonic seawater nasal spray is ideal. It is highly recommended in the international consensus on allergic rhinitis (grade A recommendation). The morphology of its tip is adapted to the nostrils, you can adapt the quantity sprayed, and the natural solution of sea water is rich in trace elements . Microdiffusion spraying allows a gentler but also more effective wash. Physiological saline pods can help if you don't have your spray on hand.

To decongest an inflamed mucosa, a hypertonic seawater-based spray is recommended. You can watch our video on the benefits of nasal hygiene.

Anti-allergen protection

Some protective sprays or powders should be sprayed in the morning or even every 6 hours:they help the mucous membrane regain its barrier effect forming an impermeable film. Vegetable cellulose, or the combination of clay and vegetable oil are good ramparts for example.

Washing the eyes

Similarly, eye hygiene requires washes with saline or eye wash solutions enriched with cornflower water known for its soothing properties. The cleansing and soothing solutions also relieve irritation. You can read our article on fighting eye strain.

Hair also stores pollen and pollution. Shampooing in the evening helps to wash away the particles accumulated on the hair in order to avoid allergies on the pillow!

Drug treatments

Nose and eye washes are a big part of treating pollen allergy. If despite these precautions, you still experience symptoms, there are drug solutions. Your pharmacist can advise you on a short-term treatment. For persistent symptoms, it is necessary that you consult your doctor.