You often carry out a radon measurement when buying houses and properties. But what is radon and why do you need to measure it and why is it dangerous?
Radon is dangerous
Radon is an element with atomic number 86 and the chemical symbol of Rn. It is a so-called “inert” gas, which means that it exists in a gaseous state at room temperature and that the element radon does not readily react with other substances. However, radon gas is radioactive and decays by itself. When the radon decays, it emits ionising radiation containing dangerous alpha particles.
Ionisation means that electrons are removed from a nucleus by means of radiation, for example. The atoms, which were previously in equilibrium, then become charged ions which are able to react with other atoms or ions. Such reactions can damage and/or alter a DNA molecule and cause mutations or cancer or can kill cells. For that reason, ionising radiation, and therefore radon, is dangerous to humans.
Why are you exposed to radon in a building?
In its normal form, as stated above, radon exists as a gas. Isn’t it just a matter of airing the building to let the radon out? Yes, in a way it is. Some types of radon problem are solved just through ventilation. But, unfortunately, the gas fills up constantly if a building is constructed on ground that causes radon gas to form.
Radon derives from a “decay chain”, i.e. other radioactive substances decay and form new substances. Uranium and radium, two radioactive elements that exist in certain types of bedrock, are present earlier in this chain. In areas with high uranium levels or radium-rich ground, the risk of so-called “soil radon” will be higher. Radon is particularly common in buildings with basements because the walls are more exposed to the surrounding ground.
Long-term effects and radiation doses
Elevated radon levels in a building can cause an increased risk of cancer and particularly of lung cancer. When you live and spend a lot of time in the building, radon can gradually cause harm. However, the risk is very small for non-smokers. Nowadays, it is recommended that the radon level should be no higher than 300 Bq/m3 in rooms in which you spend a lot of time (WHO is recommending no more than 100 Bq/m3). If the value is higher, you should take action to deal with the radon problem, for example through ventilation or sealing against incoming soil radon.