Allergies affect up to 40% of the world's population, and the proportion of sufferers is on the rise. Symptoms are aggravated by air pollution.
Birch, cedar, poplar and other trees are starting to pollinate, marking the return of spring allergies for many. Runny nose, watery eyes, sneezing and coughing ... They may be symptoms or signs of cold but if you still have them after 2 weeks, it must be a respiratory allergy.
The causes of respiratory allergies are mostly genetic. Their increase is related to our urban living environment, where our immune defenses are weakened for multiple reasons. Small apartments, isolated and air-conditioned, favor the proliferation of mites. To the mites are added the hairs of our pets, also triggers of allergies. Our immune system is unable to adapt. Thus, the presence of non-hazardous bacteria, which have been part of our environment for hundreds of millions of years, can trigger an over-exaggerated response. The overconsumption of antibiotics does not help. Finally, outdoor air pollution (fine particulate matter, diesel emissions) and indoor air pollution (tobacco, formaldehyde, heavy metals, VOCs ...) aggravate symptoms. Staying at home is not the solution! External pollutants penetrate our homes through infiltration (windows, doors, chimneys, etc.) and the ventilation system and are added to the internal pollutants. Pollen, once inside, can keep their allergenic capacity up to a year!
Allergens, especially pollens, have a complex relationship with air pollutants.
On the one hand, pollutants aggravate pollen toxicity:
On the other hand, the fine particles we breathe irritate the respiratory and ocular mucous, making the respiratory tract more receptive and facilitate the accessibility of pollens in the organism. The sensitivity of individuals to pollen is thus increased during pollution peaks. That is why even in cities where there is little greenery, the population is sensitive to allergies.
The increase in the frequency of allergies in recent years is in line with the increase in air pollution. Pollution is not the direct cause of allergies, but it aggravates symptoms.