Of natural origin and yet the second most common cause of lung cancer? It is no coincidence that the radioactive noble gas radon is attracting increasing attention as an indoor pollutant. This is because high radon levels in buildings are not “natural”. If there is a radon problem in a building, then it is a “building problem”.

Text Wolfgang Ringer

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Lung cancer due to radon

Radon is a radioactive noble gas. It is produced by the radioactive decay of uranium in rock. Since uranium occurs everywhere as a trace element, radon is also formed in all soils. Radon escapes from the soil into the room air through cracks and fissures in the building foundations. The so-called chimney effect creates a slight negative pressure, which draws soil air and thus radon into the house. In closed rooms, this can lead to an accumulation of radon in the air we breathe. Outdoors, radon evaporates quickly and is harmless to health. In buildings, however, high concentrations can occur that pose a health risk. According to the World Health Organization (WHO), radon is the second most common cause of lung cancer after smoking [1]. In Austria, around 400 deaths per year are attributed to indoor radon exposure.

Radiation Protection Act and Radon Protection Ordinance

Radon protection is regulated in the Radiation Protection Act [2] and the Radon Protection Ordinance (RnV) [3]. Key aspects are the definition of a reference value, the definition of radon protection and radon precautionary areas, regulations for protection against radon in the workplace and the definition of measures for protection against radon.

Radon protection in building law

Nowadays, new buildings can be constructed in such a way that no high radon concentrations occur. OIB Guideline 3 “Hygiene, Health and Environmental Protection”, 2023 edition, stipulates that buildings with habitable rooms in radon protection and radon precaution areas must be designed in such a way that the entry of radon from the subsoil, which is hazardous to health, is prevented. This requirement is deemed to be met if the reference value of 300 Bq/m³ in the room is not exceeded. The structural measures that may be necessary for new buildings can be found in ÖNORM S 5280-2 [4]. Examples of structural measures are the convection-tight design of components in contact with the ground, see diagram, or the installation of radon drainage. For existing buildings, there are tried and tested measures to reduce radon levels. ÖNORM S 5280-3 [5] provides assistance.

Information, advice, training, measurement

More detailed information is available on the websites of the Radon Expert Office (www.radon.gv.at), the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology (BMK), the Austrian Federal Economic Chamber (WKO), the Company Service Portal (USP) and in the FAQs on OIB Guideline 3. The Radon Expert Office of AGES offers training courses on structural radon protection, which can also be integrated into training programs of interest groups in the construction industry. The list of trained experts for structural radon protection is available at www.radon.gv.at . A radon infoline (+43 50555 41800 or radonfachstelle@ages.at) is available for information and advice as well as for carrying out radon measurements.

Bibliography and list of standards

[1] World Health Organization: WHO Handbook on Indoor Radon, WHO, Geneva 2009.[2] Radiation Protection Act 2020 (StrSchG), Federal Law Gazette I No. 50/2020.[3] Radon Protection Ordinance (RnV), Federal Law Gazette II No. 470/2020.[4] ÖNORM S 5280-2: Radon. Part 2: Structural precautions for buildings, July 15, 2021.[5] ÖNORM S 5280-3: Radon. Part 3: Remediation measures for buildings, January 1, 2024.