- Pollen produced by plants can cause allergic rhinitis that occurs at certain times of the year, mainly in spring, the season during which most plants flower.

- Fungi and mold originate from soil and vegetation, they are in fact responsible for the natural decomposition of organic matter. Fungi colonies release very small particles (invisible to the naked eye), called spores, into the air. These spores can be transported in the air for long distances and enter buildings. When they encounter surfaces capable of providing humidity and nutrients in sufficient quantities, they form a new colony that can be seen with the naked eye, for example mold on the walls of the house.

The proliferation of microorganisms such as bacteria and fungi is often favored by the failure to adopt a protocol in the maintenance and setting of temperature and humidity in relation to air conditioning systems.
This happens because the filters of air conditioning systems retain microorganisms that can proliferate inside the filters themselves which act, if not replaced frequently, as a breeding ground with the result that fungi and bacteria are continuously released into the environment through the contaminated filters.

For this reason, the cleaning and maintenance of air conditioning filters and central heating systems must be done regularly.

Fungal colonies are evident as mold spots, they can be green, white or bluish in color and appear on walls, plant surfaces, foods, fabrics and other materials.
In some cases it is possible to smell a characteristic odor commonly known as “mold smell”.
Normally, mold smell and visible mold mean problems in the air quality, due to the large quantity of spores released.

It is best to eliminate mold outbreaks and bubbles before they appear, because in addition to the health consequences, mold destroys the surfaces where it proliferates, and can permanently damage electronic equipment.
A fungal colony, a mold spot, causes a continuous release of spores into the air. When we inhale them, they can trigger allergic crises causing breathing difficulties, nasal congestion, colds, sneezing, throat irritation, coughing, fatigue and difficulty concentrating.

- Proceedings against builders, contractors, architects, building maintenance workers for the scarcity of construction materials used, architectural and maintenance errors.

- Viruses and bacteria are the cause of many diseases such as: colds and flu, meningitis, tuberculosis and pneumonia, which can be spread in the air by infected people without direct physical contact between them and healthy people.

- Mites are arachnids of the same family as spiders. These microorganisms are responsible for 80% of respiratory allergies in humans, including the most serious of these: asthma.
A gram of dust can contain more than 40,000 mites and millions of their allergens but just 100 mites per gram of dust are enough to trigger allergic reactions!

- Many people know that pets cause allergies and almost everyone associates these reactions with animal hair. In fact, fur can accumulate allergens such as fungi, mites and pollen, but in reality the main allergenic substances are proteins present in the skin, sebaceous secretions and saliva of these animals.
For asthmatic people, attention in relation to pets must be considerable, since several studies demonstrate a strong correlation between asthmatic attacks and the presence of animals in the home.
The proteins that cause allergies can remain suspended in the air and persist in the environment for days. They are easily transported to different environments, manifesting their presence even in places closed to animals.