In order to achieve robust buildings, it is necessary to put a stop to the radon gas, whose presence inside them causes serious problems for the health of people. In fact, according to the World Health Organization (WHO), it causes between 3% and 14% of lung cancer cases.
How does radon originate?
It comes from the rocky soil with a high uranium content. As it disintegrates, it decomposes and spreads through air and water. The subsoils that produce the greatest amount of radon are those with the presence of granites and shales.
In which areas of Spain is it most present?
The problem exists throughout the peninsula, although the highest concentrations are found in Galicia and in the Guadarrama mountains of Madrid. The potential map of radon in Spain of the Nuclear Safety Council (CSN) shows this in detail.
Where does radon enter the buildings?
We spend most of our lives inside buildings; in fact, it is estimated that we are in them 75% of the time. The radon gas that emanates from the underground rises to the surface and enters the inside of the buildings unless it is met with a barrier. It dissipates on the outside, so it does not pose a health risk.
While it is mainly transmitted through the soil, it can also enter through vents and, to a lesser extent, through the water supply and domestic gas. In addition, errors in construction design and lack of watertightness can lead to its accumulation. In summary, wall air chambers, basement floors and walls, sewerage pipes and sanitary ware are the most common routes of entry for radon.
What are the amounts of radon gas that should not be exceeded?
According to the international legislative framework on radon, the European Commission, in Euratom 90/143, recommends not to exceed concentrations of 400 Bq/m³ in existing buildings and 200 Bq/m³ in new buildings. For its part, the International Commission on Radiological Protection, in its review of radon exposure levels presented in 2009, reduced the maximum level for housing from 600Bq/m³ to 300Bq/m³.
How can I measure the amount of radon gas in my home?
According to the CSN, it is best to go to an accredited laboratory or laboratory suppliers to carry out the measurement in accordance with ISO 17025. They send the detectors by mail, which must be returned to them after the time stipulated for their analysis.
What measures should be taken if a building exceeds that limit?
If the concentration is a few hundred Bq m³, an effective measure is natural ventilation, taking into account that radon accumulates throughout the night. If the measurements are high, constructive measures must be considered.
In new constructions, one solution is to place ventilated floor slabs, as well as to place anti-radon barriers in the enclosures. In existing buildings, it is essential to seal joints and cracks, insulate basements and garages, place anti-radon barriers in contact with the ground and install a mechanical ventilation system in those rooms with higher concentrations of radon.