Radon is a naturally occurring, radioactive noble gas. It is produced by the radioactive decay of uranium, which is found in all soils and rocks. As a gas, radon escapes from the ground and mixes with the air. Radon is odorless, colorless and tasteless and cannot be detected by humans.

Radon enters the indoor air of buildings from the building subsoil through cracks and fissures in the foundations. Radon can also be released from building materials. Under unfavorable conditions, high radon concentrations can occur in buildings. Outdoors, however, radon evaporates quickly.

The World Health Organization (WHO) classifies radon and its derivatives as a proven carcinogenic substance. Radon is therefore on the same level as tobacco smoke and asbestos. In addition, radon is the largest contributor to average human radiation exposure in Austria. Radon is the most common cause of lung cancer after smoking! In people who have never smoked, radon is even the most common cause of this type of cancer. According to current knowledge, other health complaints are not caused by radon.

Strictly speaking, the radon by-products lead, polonium and bismuth are responsible for the harmful radiation exposure. As a gas, radon only remains in the airways for a short time and is quickly exhaled again. The radon by-products, however, remain in the moist airways. The radon by-products can damage cells in the lung tissue and thus lead to lung cancer.

Only a measurement of the radon concentration in the indoor air of your home can provide clarity. No two houses are the same, as the radon concentration depends on various factors. These include the geological composition of the soil, the construction of the building and the ventilation behavior of the occupants. No two houses are the same. To determine the radon concentration, you need to carry out a long-term measurement.

As part of its radon protection activities, the Federal Ministry of Agriculture, Forestry, Climate and Environmental Protection, Regions and Water Management (BMLUK) provides a free radon measurement with two radon detectors in your private household. The BMLUK provides a contingent of radon detectors twice a year for these measurements.
Further information on free radon measurements in private households can be found here.

A long-term measurement lasts approximately six months. This records daily and seasonal fluctuations in the radon concentration in the house. More than half of the measurement period should fall within the heating period.

The measurement is carried out with two radon detectors in the two most frequently used living rooms. The measuring devices must remain in the same room for the entire measurement period. However, the living rooms should be used as normal.

No, the radon detector does not need to be switched on. Simply remove the radon detector from the packaging. The radon detector will start measuring from this point.

No, radon detectors are not dangerous, do not make any noise and do not emit any radiation. They are about the size of film cans, are made of plastic and do not require a power supply.

The two radon detectors are set up in the two most frequently used living rooms, as the radon concentration should be determined where you spend the most time, usually in the living room, children's room, bedroom or kitchen.

No, it does not make sense to measure radon in unoccupied basements. The radon concentration should always be measured in the two living rooms where you spend most of your time.

Note: However, if one of the two most frequently used living rooms is in the basement, for example a child's room, the measurement can take place there.

Radon detectors should be set up out of the reach of children and animals. In principle, a free space should be chosen for the detectors that:

1. is not directly next to a window or door (avoid draughts),
2. is not heated (by sunlight or heating),
3. is at least 10 cm away from the wall and floor.

Please note that the detectors must remain in the same room for the entire measurement period.

In principle, the radon concentration indoors should be as low as possible. However, there is a reference value. This is 300 becquerels per cubic meter of air (Bq/m³) and refers to the annual average radon concentration.

In this case, there is no need for action.

Note: If you are planning renovations or conversions (window replacement, full thermal insulation, breakthroughs in the foundation area), discuss the issue of radon with the company carrying out the work. This is because structural changes to the building can lead to an increase in the radon concentration indoors.

If there is too much radon in your home, you need to take action!

As an initial measure, regular cross and shock ventilation in the living area or the conversion of rooms can help. There are simple and proven methods for permanently reducing radon concentrations. For initial information, please contact the Austrian Radon Office or your regional building department! There are currently no companies in Austria that specialize in radon remediation. The training of specialists in structural radon protection is currently under development.

No, there is no limit value. There is no threshold below which radon is no longer harmful to health. Therefore, the lower the radon concentration, the better.

Yes, radon protection is regulated by building legislation in all federal states.

There are various structural measures to protect against radon, which are defined in an Austrian standard (see ÖNORM S 5280-2 Radon - Technical precautionary measures for buildings).

Basically, the tighter the building envelope is sealed against the ground, the lower the radon risk. Preventive measures are also much simpler, cheaper and more efficient than retrofitting. Seek advice from a specialist to find the best solution for your new home.

Note: A control measurement is recommended after completion of the building.

Note: Upper Austria promotes preventive measures for new buildings in radon risk areas

The measurement of radon in soil air (soil gas measurement) is technically possible in principle. However, it is not recommended, as it is very time-consuming and cost-intensive, but not very meaningful. The radon concentration depends not only on the soil gas concentration, but also on the construction of the building. It is simpler and more effective to install precautionary measures in new buildings.

Radon precautionary measures are mandatory in Austria.

The province of Upper Austria has published a brochure on precautionary measures for new buildings and general renovations.

Simple radon remediation costs a few hundred euros. If the remediation measures are more complex, costs of up to 10,000 euros can be incurred. Measures range from sealing building components such as the floor slab to extracting the soil air underneath the floor slab. Various measures are listed in ÖNORM S 5280-3 Radon - remediation measures in buildings.

Note: A control measurement is recommended after radon remediation.

Note: Upper Austria, Styria and Tyrol promote structural remediation measures for high radon concentrations.

If possible, clarify the radon situation with a long-term measurement. A long-term measurement takes about six months and should always be carried out when the room is in normal use. A measurement therefore only makes sense in occupied rooms.

Short-term measurements are not recommended, as no meaningful comparison with the reference value is possible.

Tip: What you should consider when buying a house

In most cases, drinking water has no effect on indoor radon concentrations.

Only in individual cases can the radon dissolved in water lead to an increased radon concentration in homes, for example if the water supply comes from the home's own well or the water is piped directly from the source into the house. However, the contribution to overall radon exposure is generally negligible. In addition, the Drinking Water Ordinance regulates how high the radon concentration in drinking water may be. Official inspections are carried out regularly.