Radon maps and radon-prone areas: country by country

Short answer. Of the 62 countries compared, 11 publish an official radon map detailed to a grid, a municipality or an address, from Germany's 1 × 1 km grid ⁶ to France's three categories per commune ⁵. Sixteen offer only a regional picture, a national page, a list or the European Commission's 10 km atlas ². For the other 35, official sources reviewed gave no confirmed radon map.

How do the 62 countries compare?

Each country links to its full page. "Not found in official sources" means the survey found no official radon map or list for that country. "Unconfirmed" means a radon map is said to exist, but its official page could not be opened and read, so nothing about it is stated here. Radon reference levels are only given where a verified source states them; see our air section for the other air data.

Europe

Americas

Asia and Oceania

Middle East and Africa

Which countries map radon down to a grid, a municipality or an address?

Eleven countries publish an official map fine enough to locate a town or a neighbourhood. Three use a grid. Germany's forecast of radon in soil is the finest grid cited, at 1 × 1 km, searchable by place or postcode ⁶. Switzerland maps the probability that a building exceeds 300 Bq/m³ ²³. The Czech Republic maps a radon index from the bedrock ³. Ireland shows High Radon Areas you can search by address; the size of its grid cells is unconfirmed ⁸.

Five work by municipality or smaller. France sorts each commune into one of three categories under the order (arrêté) of 27 June 2018 ⁵. Austria classes municipalities by potential, about 500 of them high ¹. Spain has both a gridded potential map ²⁰ and a municipal zoning, zones I and II, used by its building code ²¹. Portugal goes down to the freguesia, a parish smaller than a municipality ¹⁶, and Slovenia names the municipalities with more radon and offers free measurements in them ¹⁹.

The United Kingdom maps Radon Affected Areas and sells a probability report for a single address ²⁴. Norway's awareness map uses four classes of polygons, but warns that it is no finer than 1:50,000 and cannot judge one plot ¹⁴.

Which countries only give a regional or national picture?

Canada reports survey percentages for 121 health regions and publishes no official map ²⁵. The United States sorts each county into one of three zones ²⁶. In Estonia, the maps cover the whole country in a preliminary version, Harju County and Tallinn, as PDF files ⁴.

Italy keeps a national archive of more than 50,000 validated measurements, but the priority areas are designated region by region ⁹. Sweden has no national map and says the geological maps are too imprecise for one house; some municipalities have their own ²². The Netherlands has a radon page but no official map by municipality was found ¹³.

Three countries publish something that is not a home-risk map. Latvia's dataset covers workplaces and public buildings in 2016-2017 ¹¹. Israel lists licensed radon testers ²⁸. South Korea's open dataset is synthetic, generated for AI training, and cannot serve as a risk map ²⁷.

In Luxembourg ¹², Poland ¹⁵ and Slovakia ¹⁸, an official radon page or map exists, but its level of detail could not be confirmed.

Where is the European atlas the only map?

The European Commission's European Indoor Radon Map gives averages per 10 × 10 km cell, for viewing only ². It is the only map found for Cyprus and Malta. In Greece, the national authority runs a measurement service, but its radon map did not respond ⁷. In Serbia, no map was found on the authority's site ¹⁷. Italy also appears in the atlas ².

Where was no official radon map found?

For 27 countries, official sources gave no radon map or list: Argentina, Brazil, Chile, Colombia, Costa Rica, Georgia, Hungary, Iceland, India, Indonesia, Japan, Kazakhstan, Kuwait, Malaysia, Mexico, Moldova, New Zealand, Peru, the Philippines, Qatar, Romania, Singapore, South Africa, Taiwan, Thailand, Ukraine and the United Arab Emirates. In Bulgaria and Turkey, no published map was found either.

For six more, Australia, Belgium, Croatia, Denmark, Finland and Lithuania, the survey pointed to an official radon page, but it blocked automated access or timed out when checked, so nothing about it is stated here. These cells stay "unconfirmed" until the page is read. That makes 35 countries without a confirmed official map.

Frequently asked questions

Does a low-risk area mean my home is safe?

Not necessarily. Norway says its map cannot be used for a single plot ¹⁴, and Sweden calls geological maps too imprecise for one house ²². Even the United Kingdom, which works by address, gives a probability rather than a measured level ²⁴.

Which radon maps can be downloaded as data?

France's municipal categories ⁵, Spain's potential map as a shapefile ²⁰, Norway's awareness map ¹⁴ and the US EPA zones ²⁶ can be downloaded. Austria offers an OGC API and an INSPIRE download ¹, and Switzerland serves its layer without a key ²³. Others, such as Germany ⁶ and Ireland ⁸, are view-only on the page.

What reference level do these countries use?

Only a few verified pages state one. Estonia ⁴ and Sweden ²² give 200 Bq/m³. The Swiss map is built on the probability of exceeding 300 Bq/m³ ²³. For other countries, this page gives no figure because none was confirmed in the sources reviewed.

Do basements and underground shelters need special care?

Our guide to radon in basements and underground shelters explains testing and ventilation for spaces you plan to use for long stays.

Fitting radon into your plan

If you plan to spend long periods in a basement or underground shelter, check your country's map in the table, then measure the room itself. The Phaenyx plan lets you record that result alongside the rest of your household preparations.

Sources

1. AGES (Agentur für Gesundheit und Ernährungssicherheit) — Radonpotenzialkarte der Republik Österreich — https://www.data.gv.at/katalog/datasets/a6ff6bd0-0136-4991-aae9-05869910a43f (accessed 2026-10-27)
2. European Commission – Joint Research Centre (REMAP) — European Indoor Radon Map (European Atlas of Natural Radiation) — https://remap.jrc.ec.europa.eu/Radon.aspx (accessed 2026-10-27)
3. Česká geologická služba (ČGS) — Mapa radonového indexu z geologického podloží — https://mapy.geology.cz/radon/ (accessed 2026-10-27)
4. Kliimaministeerium (Eesti Geoloogiateenistus) — Radoon (radooniriski kaardid) — https://www.kliimaministeerium.ee/elurikkus-keskkonnakaitse/kiirgus/radoon (accessed 2026-10-27)
5. ASNR (formerly IRSN) — Connaître le potentiel radon de ma commune — https://www.data.gouv.fr/fr/datasets/connaitre-le-potentiel-radon-de-ma-commune/ (accessed 2026-10-27)
6. Bundesamt für Strahlenschutz (BfS) — Radon im Boden — https://www.bfs.de/DE/themen/ion/umwelt/radon/karten/boden.html (accessed 2026-10-27)
7. ΕΕΑΕ (Greek Atomic Energy Commission) — Μετρήσεις ραδονίου — https://eeae.gr/metriseis-radoniou/ (accessed 2026-10-27)
8. Environmental Protection Agency (EPA) Ireland — Radon map — https://www.epa.ie/environment-and-you/radon/radon-map/ (accessed 2026-10-27)
9. Istituto Superiore di Sanità (ISS) — Protezione dal radon — https://www.iss.it/radon (accessed 2026-10-27)
10. ISIN – Ispettorato nazionale per la sicurezza nucleare e la radioprotezione — Radon — https://www.isinucleare.it/it/radon (accessed 2026-10-27)
11. Vides aizsardzības un reģionālās attīstības ministrija / VVD Radiācijas drošības centrs — Radona gāzes līmeņa novērtējums Latvijā 2016./2017. gadā — https://data.gov.lv/dati/api/3/action/package_show?id=radona-gazes-limena-novertejums-latvija (accessed 2026-10-27)
12. Ministère de la Santé (Luxembourg) — Radon — https://sante.public.lu/fr/espace-citoyen/dossiers-thematiques/r/radon.html (accessed 2026-10-27)
13. RIVM — Radon en thoron — https://www.rivm.nl/radon (accessed 2026-10-27)
14. NGU (Norges geologiske undersøkelse) / DSA — Radon aktsomhet — https://data.norge.no/en/datasets/20a76841-0bb1-4096-b1c2-1b95fa439c49/radon-aktsomhet (accessed 2026-10-27)
15. Państwowa Agencja Atomistyki (PAA) — Poznaj Radon — https://www.gov.pl/web/poznajradon (accessed 2026-10-27)
16. Agência Portuguesa do Ambiente (APA) — Mapa de suscetibilidade ao radão — https://apambiente.pt/prevencao-e-gestao-de-riscos/mapa-de-suscetibilidade-ao-radao (accessed 2026-10-27)
17. SRBATOM — SRBATOM – Direktorat za radijacionu i nuklearnu sigurnost i bezbednost Srbije — https://www.srbatom.gov.rs/srbatomm/ (accessed 2026-10-27)
18. Štátny geologický ústav Dionýza Štúra (ŠGÚDŠ) — Radón (Geoinfoportál) — https://www.geology.sk/geoinfoportal/tematicke-aplikacie/radon/ (accessed 2026-10-27)
19. Uprava RS za varstvo pred sevanji (URSVS), gov.si — Zmanjševanje izpostavljenosti radonu — https://www.gov.si/teme/zmanjsevanje-izpostavljenosti-radonu/ (accessed 2026-10-27)
20. Consejo de Seguridad Nuclear (CSN) — Mapa del potencial de radón en España — https://www.csn.es/mapa-del-potencial-de-radon-en-espana (accessed 2026-10-27)
21. Consejo de Seguridad Nuclear (CSN) — Mapa de zonificación por municipio — https://www.csn.es/mapa-de-zonificacion-por-municipio (accessed 2026-10-27)
22. Strålsäkerhetsmyndigheten (SSM) — Radon — https://www.stralsakerhetsmyndigheten.se/omraden/radon/ (accessed 2026-10-27)
23. Bundesamt für Gesundheit (BAG/OFSP) — Radonkarte (map.geo.admin.ch, layer ch.bag.radonkarte) — https://map.geo.admin.ch/ (accessed 2026-10-27)
24. UK Health Security Agency — UKradon – UK maps — https://www.ukradon.org/information/ukmaps (accessed 2026-10-27)
25. Health Canada — Cross-Canada Survey of Radon Concentrations in Homes – Final Report — https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/radiation/cross-canada-survey-radon-concentrations-homes-final-report-health-canada-2012.html (accessed 2026-10-27)
26. US Environmental Protection Agency (EPA) / USGS — EPA Map of Radon Zones — https://www.epa.gov/radon/epa-map-radon-zones (accessed 2026-10-27)
27. Korea Environment Corporation (KECO), data.go.kr — 한국환경공단_실내 라돈 측정 합성데이터 조회 서비스 — https://www.data.go.kr/data/15153598/openapi.do (accessed 2026-10-27)
28. Ministry of Environmental Protection, data.gov.il — Radon practitioners — https://data.gov.il/dataset/radon-practitioners (accessed 2026-10-27)