Polish Chief Sanitary Inspectorate on European Radon Day: reference level 300 Bq/m³, annual measurements with track detectors in the heating season, and laboratories report exceedances to the regional sanitary inspector
On 6 November 2026, ahead of European Radon Day held on 7 November, the birthday of Maria Skłodowska-Curie, Poland’s Chief Sanitary Inspectorate (GIS) reminded when a radon measurement result in a building has to be reported to the sanitary inspection, and recommended carrying out measurements in the heating season, from October to March.
- The reference level is 300 Bq/m³ of annual average radon activity concentration in indoor air. The Chief Sanitary Inspector identifies areas where this concentration may be exceeded in a significant number of buildings and supervises the national action plan for long-term risks from radon exposure in buildings intended for human occupancy and in workplaces (Monitor Polski item 169).
- In a workplace where, despite measures in line with the optimisation principle, the radon concentration exceeds 300 Bq/m³, the head of the organisational unit must notify the regional state sanitary inspector (Article 51(2) in conjunction with Article 4(1a)(15) of the Atomic Law Act, Journal of Laws 2024 item 1277).
- Laboratories measuring annual average radon concentrations themselves inform the regional state sanitary inspector of an exceedance when the measurement was ordered by a person renting out or selling a dwelling. The list of laboratories accredited for this work is on the website of the Polish Centre for Accreditation, and GIS recommends measurements in the heating season from October to March.
- Annual average indoor radon concentrations are measured with track detectors in a diffusion chamber: the detector is exposed in the room under investigation for a strictly defined time and read out after exposure — most often in a specialised laboratory.
- Radon in soil gas is measured with an RM-2 meter with IK-250 ionisation chambers or with a system of scintillation chambers (Lucas cells) with a photomultiplier and pulse counter; in boreholes after geotechnical soundings, at the foundation depth of the building or deeper, activated charcoal detectors, ionisation chambers (short-term measurements) or track detectors (long-term) are used.
- Radon enters buildings through cracks in foundations and floors, construction joints and gaps around pipes, and building materials containing natural radioactive isotopes can also be a source. According to GIS, cement-lime plaster with a double layer of oil paint reduces the radon exhalation coefficient by about 75 %, emulsion paint by about 35 % and distemper by about 20 %; sub-slab depressurisation (a radon sump) is regarded as the most effective reduction method.
Source: GIS — European Radon Day: an invisible gas, a real hazard! (06.11.2026)