Help the development of the site, sharing the article with friends!
Radon gas in buildings
In an article we have already talked about the health of buildings and their facilities, and how it can affect their occupants. It is a subject that can become difficult to deal with when we are already talking about external factors that affect the building itself.
Although we already talked about how to disinfect the house thoroughly, there are other problems that we do not see. The perpetual, high-risk example is the radon gas, which in some buildings accumulates to the point that it poses a serious risk to human health.
This carcinogenic gas may sound distant to us, but, according to experts, around 250,000 buildings in Spain could be accumulating radon gas. Obviously, we are facing an important issue that must be addressed.
Recently the Technical Building Code in Spain has launched a series of technical documents on detection, diagnosis and protection of buildings against radon gas, which undoubtedly have a high value and that we need to know and see …
What is radon gas?
The Radon gas is a noble gas of natural origin that is generated from the radioactive decay of uranium and it is present in soil, rocks, water and even some construction materials.
One of its main characteristics is that it easily emanates from the ground and passes into the air, where it disintegrates and emits radioactive particles that can be inhaled and deposited in respiratory cells, where they can produce DNA mutations and cause lung cancer.
At the end of the article there are several technical guides that explain more fully how it affects health, but, as an important fact, according to the WHO, in many countries, radon is the second most important cause of lung cancer after tobacco.
In reality, most buildings contain radon in low concentrations (concentrations well below 300 Bq / m3 , which we will talk about this number later). But, there are geographical areas in which, due to their geology, it is more likely to find buildings and constructions with higher levels.
Sandy, granitic and gravel soils favor gas to flow to the outside because they are more porous, while compact and clayey soils, less permeable, allow a lower concentration of radon to emanate.
In the case of the Spanish territory, always speaking of "potential", in the following radon gas concentration map in Spain We can already distinguish the areas with high forecasts (The map can be consulted from HERE and it loads very slowly):
For those users who want to investigate more and see by populations - specific areas - in official fashion - for the Spanish state. From the HS Basic Health Document that we can consult HERE, at the end, from Page 161, is the classification of municipalities based on radon potential.
What regulations are there in the control of buildings?
Here, we are not going to extend much since at the end of the article there is an extensive and explanatory video in format for technical professionals of all the detailed regulations, but yes, in general, the regulatory framework for radon in Spain current:
The regulatory framework for the building can be consulted from the Basic Document DB HS 6 in the Technical Building Code itself (Spain). We would only like to outline a noteworthy point that has been a constant debate.
According to the current regulations for Spain, takes as a reference level the annual average radon concentration of 300 Bq / m3 at the national level and, in accordance with Directive 2013/59 / EURATOM. However, clearly, the WHO proposes a reference level of 100 Bq / m3 to minimize health risks from indoor radon exposure We don't get it! But this is another debate.
But… How does radon gas get inside a building? Or a home, because we really have three main routes that we are going to see now …
How does radon gas get into buildings?
When radon reaches the outdoor environment, it quickly dissolves into the air, but when it does so in a closed and poorly ventilated space, such as inside a building, it tends to accumulate, becoming a problem. Radon inside buildings can come directly from:
| Ways by which we find randón | How it can affect us | Randón levels |
| Radon coming from the ground | By convection through the cracks or areas of the building envelope in contact with the ground (basement walls, sills, etc.) | HIGH (Levels can be very high) |
| Radon coming from materials | For the construction materials that have been used in the construction of the work | LOW (the average radon concentration inside houses with a value between 10 and 20 Bq / m3) |
| Radon that comes from water | By consuming groundwater (from springs or wells) without aeration | LOW (In surface waters, the average radon concentration is usually less than 0.4 Bq / l and if the water comes from underground sources the value is around 20 Bq / l) |
As we see in the table above, the high levels of radon can be found in the areas of the building that are in contact with the ground. This is where the issues to be addressed are and an important technical difficulty for any action on the foundations of buildings and basements.
The main route of entry for radon gas into buildings is through the ground!
The building envelope that is in contact with the ground will be the main point before a possible rehabilitation to reduce radon emissions inside the house. An outline of possible access routes:
What aspects influence the increase in radon in homes?
Although the amount of radon that we can find inside the houses It depends on many factors, which are remarkable - especially - those related to the terrain, the construction characteristics of the house, the behavior of the users or the weather:
| Radon levels increased by | |
| Ground | By the geological composition. There are types of terrain that produce a large amount of radon from high concentrations of granite, shale and shale. |
| Due to the greater permeability to the air of the terrain or greater ease of movement | |
| By the degree of water saturation of the land | |
| Building Characteristics | By the proportion of the building envelope that is in contact with the ground |
| Due to the permeability of the building to gases that exist on the ground (cracks, fissures, etc. in basements - foundations) | |
| By the type of constructive solution adopted in the execution of the house | |
| For the elements and facilities that pass through the building envelope (See article negative effects of air conditioning) | |
| By communication runs between basements and upper floors | |
| By the ventilation system | |
| Climatology | Due to the low atmospheric pressures (roughly, more common in winter) they favor the release of radon gas from the ground, and the high ones make it difficult |
| User behavior | By ventilation habits. Generally, the ventilation of the premises in contact with the ground will decrease its concentration of radon by dilution (It does not help much if we have high concentration levels) |
How is radon detected?
The radon concentrations within buildings they can be highly fluctuating. Therefore, to perform the measurement and radon detection in homes, detectors are used that make an average estimate of the amount of gas. But before measurement, we have to consider:
Remember that the annual average radon concentration should be less than 300 Bq / m3
There are different radon detectors, and your choice will depend on the purpose of the measurement. In general terms, it could be said that the detectors are classified according to the measurement method, integrated, continuous or point; and according to its power source, active or passive.
The types of radon gas detectors can measure the concentration of a gas by 3 methods:
- Integrated measurement: They are the most used due to their low cost. They use traces, activated carbon, and electrodes to provide an average. Generally, the laboratory ships the detector by mail and the user returns it after the measurement time has passed for the laboratory to perform the measurement analysis. They are generally not connected to any power source, so they are passive.
- Continuous measurement: They are electronic devices that, in addition to making an annual average, allow us to observe the evolution of the radon concentration over time, so that the alterations produced by climatic changes and other variables can be observed. They require an electrical source to function, therefore they are active.
- Spot metering: Unlike the previous two, they cannot be used to make an annual average determination, however, they are very useful for a quick diagnosis of radon entry points such as cracks, fissures, voids or other discontinuities in the structure.
What solutions can we apply to reduce radon gas in houses?
Obviously, here the application of the regulations of each country comes into play (Let us remember that, for Spain, it is the Basic Document DB HS-6 of the Technical Building Code) but this time, in addition, we will show where to find some technical sheets aimed at Professionals are delightful.
But, first, we want to show the classification of the solutions according to their form of action, which will also be matched with technical sheets:
The Guiding solutions for protection against radon in buildingsEither for a New Construction or rehabilitation (Existing buildings), the most suitable are based on the concentration of radon. For Spain it is proposed:
| Average annual radon concentration (Bq / m3) | Protection solutions |
| ≤600 | Protection barrier arrangement |
| Sealing of fissures, cracks, encounters and joints | |
| Use of watertight doors | |
| Creation of overpressure in the premises to be protected | |
| Improved containment space ventilation | |
| Improvement of the ventilation of the habitable premises | |
| >600 | Creation of containment space |
| Installation of land depressurization system |
Of course, from a technical work perspective it is necessary to treat many aspects in more detail, depth and always with qualified professionals.
Construction solutions sheets for radon gas
In addition to the applicable regulations, there is a series of 10 technical sheets of radon insulation and solutions they are help to technicians. They will provide us with ways to protect the population from the harmful health effects that can result from prolonged exposure to high concentrations of radon gas. An example starts from the quality of the documentation:
The 12 construction guides for barriers against radon gas in buildings can be consulted from HERE including the Guide Manual of the Technical Building Code.
An important issue that we must not forget is the effectiveness of the different protection solutions. Depending on the characteristics of the building and the concentration measured in question, it will be more efficient to use one construction solution or another and it will even be necessary to use solutions cumulatively.
In the attached image, it is oriented on the effectiveness of the different proposed construction solutions, distinguishing between radon concentrations higher (in red) and lower (in yellow) than 600 Bq / m3, measured in premises - living spaces.
We must not forget that we are facing a complex situation that requires complex work solutions and that they go hand in hand with the application of extensive regulations. To clarify many concepts, the following video provides an in-depth review of the new section on protection against radon:
Although radon is a harmless gas outdoors, it is a latent threat when it accumulates indoors. And, like all gas, it responds to the physical and chemical laws of concentration and pressure, which is why we must be vigilant regarding the levels it reaches inside buildings.
Few people are aware of this problem, therefore, it is important to disseminate timely and mass information regarding the risks that this substance poses to respiratory health and the appearance of lung cancer. Remember that bioclimatic architecture also contributes, in part, to buildings health.
Other guides of interest and more about how radon gas affects health in the workplace from UGT and from the National Institute of Safety and Hygiene at work HERE.
If you liked the article, rate and share!
