Some text on this page is in English for now.
Surroundings
Home, air and water. A few things matter most, and the app checks them.
The idea
Where you live shapes what you breathe and drink. A few things matter most, and a test or a quick check can tell you where you stand.
Compared with what
For radon, a gas from the ground that can gather indoors, the WHO's reference level is 100 Bq/m3 WHO, 2009. The US EPA says to fix a home at 4 pCi/L, about 150 Bq/m3, and to consider a fix from 2 pCi/L US EPA. Korea's standard is 148 Bq/m3 Korea JoongAng Daily.
Start with
- Test your home for radon. You can't see or smell it, so a test is the only way to know.
- Put your result into the app to see it next to each of these levels.
Try it
The radon slider on the home page, then the full home check in the app.
Steps to try
A small step
Test your home for radon
When I move in or before winter, I'll order a radon test kit and put it in the lowest room we use.
Sources for this page
World Health Organization (2009). WHO calls for tighter standards on indoor radon.
Health agency advice: what a public health body recommends; check the page for its own sources.
What we use: Reference level of 100 Bq/m3 for indoor radon; no higher than 300 Bq/m3 where 100 can't be reached.
Checked Oct 11, 2026 · https://www.who.int/news/item/21-09-2009-who-calls-for-tighter-standards-on-indoor-radon
US Environmental Protection Agency. What is EPA's action level for radon and what does it mean?.
Health agency advice: what a public health body recommends; check the page for its own sources.
What we use: Fix the home at 4 pCi/L (about 150 Bq/m3) or above; consider a fix between 2 and 4 pCi/L.
Checked Oct 11, 2026 · https://www.epa.gov/radon/what-epas-action-level-radon-and-what-does-it-mean
Korea JoongAng Daily. Radon in homes boosts cancer risk.
News report: second-hand; we look for the original source.
What we use: Korea's indoor radon standard is 148 Bq/m3 (4 pCi/L). A news report; replace with the Korean ministry page when found.
Checked Oct 11, 2026 · https://www.koreajoongangdaily.com/korea/radon-in-homes-boosts-cancer-risk/11729996