Short answer
Bq/m³ stands for becquerels per cubic meter, the metric unit for radon in air. Most countries report radon in it; the United States uses pCi/L.
What Bq/m³ means
WHO defines the unit: one becquerel is the transformation of one atomic nucleus per second. A reading of 100 Bq/m³ therefore means 100 radon atoms decaying each second in every cubic meter of air.
To turn Bq/m³ into
Bq/m³ turned into pCi/L
Each row divides a published figure by 37.
| Figure, Bq/m³ | In pCi/L | What the figure is |
|---|---|---|
| 5 | 0.14 | The low end of WHO's average outdoor level |
| 15 | 0.41 | The high end of WHO's average outdoor level |
| 100 | 2.70 | WHO's reference level for homes |
| 148 | 4.00 | EPA's action level |
| 300 | 8.11 | The ceiling WHO sets for a national reference level |
| 10,000 | 270.27 | WHO says indoor levels can pass this |
What it means for your home
A monitor or a lab report from outside the United States may show Bq/m³ only. Divide the number by 37 before you hold it against EPA's 4 pCi/L, or read it against WHO's 100 Bq/m³ as it stands.
The two units measure the same thing, so a home does not have two radon levels. Only the scale changes.
Where to go next
- Radon level interpreter. Read a result against EPA's levels once you have it in pCi/L.
- Radon levels explained. Every level from 1 to 100 pCi/L, with what each one calls for.