Radon in a flat: measurement, limits and risk areas
Autor Lumi · Aktualizováno: 16. 6. 2026 00:00 UTC
Radon is an odourless indoor-air risk, highest on the lowest floors. How to spot the risk, measure it, and read STUK's limits.
Tento průvodce popisuje pravidla a praxi v zemi Finsko.
This guide is only available in English.
Důležité: On the lowest and ground-contact floors radon can exceed the limit without symptoms — measure before buying.
Radon is a radioactive gas that rises from the ground into indoor air. It's odourless and invisible, but long exposure is a health risk. In Finland levels vary by area.
Where radon comes from
Radon travels from the soil into a building's lowest spaces. The risk is highest in ground-contact and lowest floors; upper apartments typically have low levels.
Limits (STUK)
STUK reference values: in an existing home the action level is 300 Bq/m³, and a new building is designed so radon stays under 200 Bq/m³. The WHO recommends below 100 Bq/m³.
The median varies by municipality — around 100 Bq/m³ in the capital region, clearly higher in some areas.
How to measure and act
Radon is measured with a detector over at least two months (three recommended) between September and May. If the value exceeds the limit, mitigation (sealing or a radon sump) is usually effective. Lumi shows the municipal median by address.
Často kladené otázky
- Is radon dangerous in an apartment building?
- Upper floors usually have low levels; the risk mainly concerns the lowest and ground-contact spaces.
- What is the radon action level?
- 300 Bq/m³ in an existing home (STUK); a new one is designed below 200 Bq/m³, and the WHO recommends below 100.
- How is radon measured?
- With a radon detector over at least two months (three recommended), September–May.
Zdroje
Viz také
Tento průvodce obsahuje obecné informace, nikoli osobní radu. Údaje a pravidla si ověřte u oficiálních zdrojů.