Convert a result
Type in either box. Uses 1 pCi/L = 37 Bq/m³.2 Nothing you type is sent anywhere.
Reference levels compared
| Who | Level | What it means |
|---|---|---|
| EPA | 4 pCi/L (150 Bq/m³) | Fix the home at this level or more.3 |
| EPA | 2 to 4 pCi/L (75 to 150 Bq/m³) | Consider fixing; there is no known safe level of exposure.3 |
| Vermont Department of Health | 4.0 pCi/L; below 2.0 pCi/L | Reduce radon at or above 4.0, and take action to get below 2.0.4 |
| World Health Organization | 100 Bq/m³ (about 2.7 pCi/L) | Recommended national reference level; if that can’t be reached, no more than 300 Bq/m³.5 |
| Health Canada | 200 Bq/m³ (about 5.4 pCi/L) | Canada’s guideline for radon.6 |
The pCi/L figures in parentheses for WHO and Health Canada are our conversions at 37 Bq/m³ per pCi/L.2 Vermont follows the EPA and Health Department levels.4
Working Levels (WL)
Some professional reports give results in Working Levels. The EPA says that if a result is in WL, fix your home if the working level is 0.016 WL or higher, and notes that some states require WL results to be converted to pCi/L to minimize confusion.7
What to do with your number
See Understanding your results for what the Health Department says to do at each level.
Common questions
How do I convert pCi/L to Bq/m³?
Multiply by 37: Health Canada says 37 Bq/m³ is equal to 1 pCi/L.2
What is 4 pCi/L in Bq/m³?
The EPA gives its 4 pCi/L action level as 150 Bq/m³.3
What does a result in Working Levels (WL) mean?
If a test result is in WL, the EPA recommends fixing your home if the working level is 0.016 WL or higher.7
Last reviewed How we source facts
Sources
7 official sources
- U.S. Environmental Protection Agency. A Citizen’s Guide to Radon (EPA 402/K-12/002, 2025). Checked 2026-10-17. ↩
- Health Canada. Guide for radon measurements in homes. Checked 2026-10-17. ↩
- U.S. Environmental Protection Agency. What is EPA’s Action Level for Radon and What Does it Mean?. Checked 2026-10-17. ↩
- Vermont Department of Health. Radon in Your Home. Checked 2026-10-17. ↩
- World Health Organization. Radon and health (fact sheet, January 25, 2023). Checked 2026-10-17. ↩
- Health Canada. Government of Canada Radon Guideline. Checked 2026-10-17. ↩
- U.S. Environmental Protection Agency. Explain Working Levels (WL) and Picocuries Per Liter of Air (pCi/L). Checked 2026-10-17. ↩