In this article we will look at the first source of biological pollution of indoor air: the presence of allergens in the dust we inhale when we are inside a building.
Whether we know it or not, we share our houses with a multitude of other occupants: bacteria, viruses, fungi and molds as well as microscopic spiders share our daily lives.
These are all living organisms, stowaways from our homes, pets and plants, that can have a direct or indirect impact on our health.
The first source of indoor air pollution is linked to the presence of allergens in the dust we inhale when we are indoors. The best known and most frequently responsible for asthma and respiratory allergies are dust mites whose dejects and decomposed bodies have a strong allergenic effect.
Dust mites are microscopic spiders that develop in hot and damp environments. Thus, they are proliferating in dust, bedding, fabric sofas and armchairs, rugs, carpets and curtains....
Why are dust mites allergenic?
Mites feed on our squames (dead skin) and molds. They produce proteins that are highly allergenic substances, particularly Der p 1 and Der f 1, which are the two main proteins that are responsible for dust mite allergy issues.
Scientific knowledge on this matter is only relatively recent, as the Der p 1 was first isolated and characterized in 1980.
During a nation-wide survey of air quality in French homes carried out by the Observatoire de la Qualité de l'Air Intérieur (OQAI) in France, it was found that in over 90% of homes, the mite allergens Der p1 and Der f1 were being detected.
In one dwelling in two, the concentration of dust mite allergen Der f1 exceeds 2 µg/g dust, a level of contamination for in which allergic people have a significant probability of developing dust mite allergy symptoms.
For Der p1 allergens, the concentration of 2 µg/g of dust is exceeded in less than 40% of homes.
For the most sensitive people, dust mite allergy can occur shortly after being exposed to a small amount of Der p1 or Der f1 allergens. The allergy symptoms are similar to those of a cold. These are principally irritations of the mucous membranes such as nose and throat and result in sneezing, coughing, nasal discharge or congestion of the nose (stuffy nose feeling). At the eye level, they can lead to itching and tear secretion.
If exposure persists, respiratory problems may appear such as tightness in the chest or breathing difficulties (asthma attack). The symptoms diminish as the person is no longer exposed to dust mite allergens.
How to detect the presence of mites?
The YOOTEST Dust mites test makes it possible to accurately measure the quantities of Der p1 and Der f1 allergens present in dust and to identify whether it is necessary to implement actions to limit their presence in indoor air.
It is recommended to test for the presence of dust mite allergens in the indoor environment if sensitive people use the building, whether it is a residential or an office building.
Only a test with a laboratory analysis can accurately determine the type of dust mite allergen present and the level of contamination.
Why can we be allergic to pets?
Second most important source of allergens after dust mites: pets. The allergens they produce come from their saliva, skin or glands. These allergens are also to be found in places where no animals live, having been transported via airborne dust or carried on clothes or under shoes.
Fel d1 cat allergens are detected in one in four dwellings and Can f1 dog allergens in 5% of dwellings. Unlike dust mite allergens, there is no guide value for a risk of developing allergic symptoms for cat and dog allergens.
About 15% of children and 60% of asthmatics are susceptible to these effects.