Indoor pollution: what are they at home? What precautions should be taken?


When it comes to pollution, very often our thoughts associate it with that of the air outside. The exhaust gases, the various odors seem easy to perceive. But the air we breathe in our domestic environment is also polluted. What are these pollutants and how toxic are they? We spend a very large part of our time indoors: at home, at work or the children at school. And it happens that the indoor air is much more polluted than the outdoor air. So what are these chemicals in the home, what are their effects and how can we protect ourselves from them?

What is indoor pollution?

In theory, the air we breathe mainly contains nitrogen and oxygen, but in reality it contains a variety of substances in tiny and varying amounts. Some of these substances are harmless to health, others are toxic in higher or lower doses. Part of the pollution of our interiors comes from outside (automobile traffic, industry, etc.), but also from our homes themselves. Many pollutants are released into the air by building materials, coatings and paints in the home or by volatile particles from furniture and household appliances. In addition, there are chemicals in detergents used for maintenance, in the fumes given off during cooking or by certain heaters, when candles or incense sticks are burnt, etc.

The air you breathe in your home contains carbon dioxide, which is naturally released by human activities, including the breathing of its occupants. All these products, particles and pollutants gradually accumulate and form what is called indoor pollution. When trying to limit energy losses in homes, we often isolate at the expense of good ventilation in the house, which leads to a gradual saturation of the ambient air. Because air quality can be quickly affected by confined space.

What pollutants are there in the air inside homes?

There are two families of indoor air pollutants: primary pollutants which result directly from pollution (nitrogen oxides released by vehicles, sulfur dioxide released during the combustion of fossil fuels, etc.) and pollutants. secondary resulting from the chemical reaction of these pollutants with their environment (with UV rays, with the oxygen present in the air, etc.).

There are three main families of products harmful to the environment inside:

Volatile organic compounds (VOCs)

Most volatile organic compounds come from exhaust gases, but are also found in many household products and coatings: solvents, wood, glues or paints. They are released indoors, sometimes for years, and affect the air quality in your home. Volatile organic compounds include polycyclic and monocyclic hydrocarbons and aldehydes such as formaldehyde, which are particularly toxic.

Microparticles (PM)

Microparticles are tiny pollutants that float in the air. Most of them are released by heating, traffic and industry. While some are visible, most are invisible to the naked eye and all the more dangerous.

Carbon dioxide (CO2)

Carbonic acid, also known as carbon dioxide, occurs naturally in the air and is not inherently toxic. However, a high concentration inside the house can have harmful effects on health. In a house, the presence of carbon dioxide can be due to outdoor pollution, but it mainly comes from the people who live there, who release carbon dioxide through their breathing.

Ambient air can also contain various other toxic chemicals such as heavy metals (lead, mercury, cadmium, etc.), combustion residues such as nitrogen oxides, sulfur dioxide and carbon monoxide.

What effects does indoor pollution have on health?

Not all substances present in the ambient air have a direct influence on your health. Some are even harmless or, like ethanol, are present in tiny amounts. However, other particles present a danger, in the more or less long term and with varying degrees of toxicity depending on their concentration and the duration of exposure. Among the volatile organic compounds, some substances are considered to be very dangerous: this is the case of benzene and formaldehyde, which irritate the respiratory tract and are carcinogenic. Therefore, there are strict regulations for the products responsible for the emission of these VOCs. Microparticles are also potentially dangerous for health, in particular because of their small size. This is because they can penetrate deep into the airways. Heavy metals are also a hazard: although they are present in small amounts, they can build up in the body over time.

Most indoor air pollutants irritate the respiratory tract, eyes and mucous membranes. This is the case in particular with nitrogen dioxide or sulfur dioxide. However, the most toxic product in the short term is carbon monoxide. Invisible and odorless, it can spread throughout the house due to a faulty heating system.

What are the solutions to fight against indoor pollution?

There are solutions to maintain indoor air quality and limit pollution in enclosed spaces. Choose products for your living room (furniture, decorative objects, coverings and cleaning products) that are respectful of the environment and do not present a toxic risk. Remember to have your boiler serviced regularly to avoid the risk of carbon monoxide poisoning. There are also detectors capable of detecting this poisonous gas. Also consider installing environmentally friendly indoor plants in your home. Their strength lies in the absorption of pollution and in particular VOCs. Even if scientists doubt the real benefits of this phyto-purification and that plants are not enough to completely eliminate pollution from homes, it remains an effective measure to improve air quality.

The essential step in reducing indoor pollution is good room ventilation. Installing an efficient ventilation system and ventilating daily are two essential actions. By renewing the air in your home, you will reduce the concentration of gases and particles, and eliminate excess humidity, also responsible for respiratory problems and mold.

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