Radon converter: pCi/L to Bq/m3.

Short answer

1 pCi/L equals 37 Bq/m3. So the US EPA action level of 4 pCi/L is 148 Bq/m3 (EPA writes it as 150), and the Health Canada guideline of 200 Bq/m3 is 5.4 pCi/L. Radon should be tested with a certified long-term test; this converter does not replace a test.

How it works, with a worked example

The conversion is a fixed ratio: 1 pCi/L = 37 Bq/m3, and 200 Bq/m3 = 5.4 pCi/L. Health Canada's measurement guide gives both. The tool multiplies by 37 for pCi/L to Bq/m3 and divides by 37 the other way.

Worked example. 4 pCi/L x 37 = 148 Bq/m3. The EPA page rounds this to 150 Bq/m3. 200 Bq/m3 / 37 = 5.4 pCi/L. A result of 2 pCi/L is 74 Bq/m3, which EPA writes as 75.

Action levels. The US EPA recommends fixing a home at 4 pCi/L or more and says to consider fixing between 2 and 4 pCi/L, because there is no known safe level. The Canadian guideline is 200 Bq/m3: Health Canada recommends corrective action within 1 year when the annual average in the normal occupancy area exceeds it, sooner for higher levels, and for lower levels as low as practicable. Health Canada recommends one long-term detector for at least 3 months, ideally in the heating season, and does not recommend a test shorter than 1 month.