Radon at home: why does a map not establish your exposure?

Radon is a naturally occurring radioactive gas that is invisible, has no smell and can accumulate inside buildings. A smell, a sensation or a symptom cannot establish its concentration. Understanding exposure in a home requires appropriate environmental information.

The radon-potential map classifies communes according to soil characteristics. High potential means that substantial concentrations are more likely inside buildings; it does not prove that every home in the commune has a high level. Check the relevant commune in official information rather than applying a regional average to your home.

The building’s features and ventilation also influence indoor concentration. Airing habits matter too. The map therefore describes a geological context; it does not replace measurements in the rooms where people live.

To establish the level in a home, detectors collect a measurement over a suitable period, after which a laboratory or organisation analyses the results. The heating season matters for this process. Ask the organisation about the measurement conditions rather than treating a single reading as representative of your whole exposure.

Ameli explains that detectors can be ordered from organisations approved to measure radon, which analyse the results. Ask the organisation about measurement arrangements and cost; this article does not guarantee locally supplied detectors or free measurement.

Recommendations for reducing exposure depend on the measured concentration. Depending on the results, ventilation or sealing work may be considered, along with checks after work where appropriate. Discuss these next steps with professionals; opening a window does not prove that the radon level has been reduced sufficiently.