Radon gas

According to the United Nations, it is the most important source of radioactivity to which the population is exposed, averaging 43 per cent of the total dose. The European Union recommends measuring radon gas at home.

It is a radioactive, but chemically inert noble gas that comes from the disintegration of uranium naturally occurring in the soil, especially granite. The human being does not detect it since it is characterized by being colorless, odorless and insipid.

The greatest exposure usually occurs in the home. The radon gas is filtered through the construction materials that are in contact with the ground. It is concentrated in the enclosures that these delimit, especially those located in  lower floors and basements.

Radon approximately lasts almost for four days, during which it disintegrates into other radioactive particles of polonium and lead.

It is the second most important cause of lung cancer. The World Health Organization (WHO) has determined that higher radon concentrations are more likely to develop lung cancer.

However, radon gas is also associated with other diseases. For example, a study by the Instituto Carlos III was published in magazines of renowned prestige that shows the relationship between this gas and other types of cancer, specifically the stomach and the brain in women.

In 2016 scientists of the National University of Distance Education (UNED) and the Nuclear Safety Council (CSN) prepared the first map that reflected the areas of Spain with the highest risk of exposure to radon. In Spain, the most affected areas are Galicia, Extremadura and Madrid. In specific areas, high values ​​are also recorded in Catalonia, Andalusia, Aragon, the Canary Islands and Navarra.

The European Directive 2013/59/Euratom gave a deadline until February 8th, 2018 for the drafting of a national action plan needed for addressing long-term risks from radon exposure. However, it does not appear that the aforementioned national plan is in force.

This directive establishes two limits to buildings for the measurement of Radon gas over time:

Buildings of new construction: 200 Bq / m³
Existing buildings: 400 Bq / m³

However, the WHO recommends lower thresholds of maximum 100 Bq/m³.

The most common method of measuring radon gas is through direct indication monitors with short duration measurements. If a radon gas measured value above a reference is obtained, repeated measurements or measurements over a longer period of time are recommended.

Depending on the permeability and composition of the soil, radon content may vary considerably. There are locations that just need to be ventilated regularly and any fissure that may appear on floors or the basements covered with silicone.

In other cases, gas radon measurements show that other preventive measures need to be taken. Long-term measures are recommended before carrying out deep and expensive clean-ups. These write-offs may consist of construction or mechanical ventilation measures.