Radon is a radioactive gas that generally comes from underground and has a natural origin. It is normally integrated in rocks and we can also find it in water. Normally it is more usual to find higher concentrations in rocks and eminently granitic subsoils.
After many years of scientific alerts , the European Union has forced Spain to take action . These measures, as you will see at the end of the article, are the new Basic Health Document (building regulations) Logically, radon affects us in places where the air moves and renews less, that is, in the buildings that we inhabit as schools, libraries and mostly homes. For this reason, it is essential to intervene in the building to protect ourselves from radon.
The WHO in this article from 2016 already warned of the dangers (scientifically proven) of radon and the measures we should take to avoid it. The disease it causes is lung cancer and it has a notable impact on the statistics of this disease.
Radon is the second leading cause of lung cancer after tobacco.
According to the WHO (World Health Organization)
In Spain, radon, as indicated in the map below by Nuclear Safety Council , is more present in some areas than in others, concentrating mainly the problem areas in the western part of the country. We also have areas with radon on the coast of Barcelona and the Pyrenees.
The main causes of lung cancer are tobacco, radon gas, asbestos, air pollution, and genetics. Changing our building, in the construction of our houses and in the reforms of them, improving the quality of the air in the houses, we can influence almost all the factors that cause this disease. Now we will see how.
Where does radon enter our home?
As we see in the image below, radon can enter our house in different ways. Here is a non-exhaustive list:
Through well water (remember that water, like air can also be contaminated with radon), although water intake is not proven to cause pathologies, it has been proven that radon in water is highly volatile.
Through cracks in floors or retaining walls
Through porous materials in contact with the ground
Through floor joints with foundations and other construction joints.
By non-ventilated air chambers in contact with the ground
Through the conduits of facilities that we pass buried
From here, by knowing where radon comes from and where it can enter, it is possible to define the areas or areas of the building most affected : low houses or schools (places of more or less permanent occupation), houses without ventilated chambers in the ground, buried spaces, places in geographical areas with the presence of radon where underground water is used without precautions.
If you live in an apartment or house that has no contact with the ground (no retaining walls, no basements, no ground floor floors) you don’t have to worry
How can we avoid radon
The solutions to build a house or rehabilitate a home that protects us against radon are varied:
barriers against radon are placed and all fissures or passages where radon can enter our home are sealed
ventilated chambers are built that dissipate the presence of radon under our home
ventilation inside the home is improved, preventing radon rates from reaching extremes that are harmful to health (the WHO establishes it at 300 Bq / m 3 ) if you are interested, read this article about the types of ventilation in buildings , or this other article about filters to prevent pathogens from entering our home.
There are ventilation systems and many manufacturers such as Soler Palau that have in their catalog elements that serve us technicians, architects and systems engineers to correctly carry out a radon evacuation in our homes.
The best time to protect yourself from radon is when the home construction is planned. Either a reform, rehabilitation or new construction.
What constructive actions should be carried out
This type of action, since it involves constructive modifications of floors or walls, it is convenient to do them when we consider rehabilitating, reforming or rebuilding our house. We are talking about works with a lot of noise and dust, they are not simple actions. We from KAITEK ARQUITECTURA will carry out a project that allows to avoid radon in your home.
Ventilated spaces under the ground floor or against the ground
This is the most effective method, contrary to what it may seem, radon barriers consisting of specific sheets can deteriorate over time. On the other hand, a good ventilation system of the air chamber space under the ground or the retaining wall will hardly deteriorate. It is recommended that these spaces be ventilated towards the deck. To avoid damaging the spaces where you can be outside.
Ventilated slab using igloo-type caissons
This element is formed mainly with a lost formwork (“caviti” or “igloo” type caissons) that have four legs, they are normally made of polypropylene. The concrete of the screed is poured over them. At the bottom these caissons leave an air chamber (there are a variety of heights depending on the needs of the project)
The sanitary slab is a floor without intermediate supports, formed by a unidirectional slab that covers the space between load-bearing walls with joists and caissons. Under this structure there is a chamber that must be ventilated through openings in the walls and the perimeter facades and / or ducts and chimneys to deck.
Ventilated chambers behind retaining walls
Like sanitary chambers and ventilated floors, they make up the most effective part of the radon protection system. In the image below we see how a retaining wall could be ventilated from the outside. It could also be carried out inside with the typical bufas cameras, but care should be taken not to introduce radon inside the living space and carry it through conduits to the deck.
Barriers against radon, specific films
They are usually high-density sheets. Either asphalt or EPDM. Recently we have seen how the sheet manufacturers began to put the name or application “vapor barrier” to sheets that they already produced under another name for other applications.
They are called this way to cavities that run through the space to be protected and that are formed by holes that lead the radon to conduits where it will be evacuated
Finally there is a regulation in Spain
Recently (year 2019) the modification of the Technical Building Code has been published where this section is incorporated into the basic HS Health document: HS6 Protection against exposure to radon.
Spanish regulations divide Spanish municipalities at risk into 2 zones: municipalities in zone I and municipalities in zone II.
The municipalities of zone I (with less risk) will be required to the buildings that have a protection barrier of radon between land and habitable premises.
The municipalities of zone II (more risk) will have to have this protection barrier and also an additional system that can be a ventilated containment space or a depressurization system from the ground that allows the extraction of gases from the ground before they reach the interior of the house.
In Appendix B of the regulations you can check if the municipality where you have your house or flat is affected. For example, we have our office in Sant Feliu de Llobregat, Barcelona, and it is actually within zone I, so we should put at least one barrier to protect against radon.
In the event of a reform or rehabilitation with expansion, it is in the enlarged part of that house where it would be mandatory to establish the measures described in the regulations. It is not mandatory to do the adaptation throughout the house.
There are radon meters
But do not worry excessively, the advantage of knowing this threat to our health is that we can take measures: reform our home or build our house well from scratch. The first step to take measurements is to know the radon levels with which we live and for that there are devices.
Spanish regulations also provide for the obligation to perform measurements and establish protocols for this. As we said, there is a wide range of devices on the market at relatively affordable prices, for example, in the link that we attach here you can buy a meter in Bq / m which are the standard units and which are WHO refers for a price of less than 200 euros.