Waiting for radon test results can be nerve-wracking. You’ve taken the right step to protect your home and your lungs, but when that report finally arrives, it often looks like a jumble of scientific jargon and confusing numbers.
Don’t panic. Understanding your radon test results is actually quite straightforward once you know what the measurements mean and where the safety thresholds lie. Let’s break down your report so you know exactly what your next steps should be.
Demystifying the Measurements: Bq/m³ vs. pCi/L
Depending on where you live and the testing lab you used, your radon levels will be reported in one of two units. Since we are looking at this from a Canadian perspective (hello, Calgary!), we will focus heavily on the Canadian standard, but it is helpful to know both.
- Becquerels per cubic meter (Bq/m³): This is the standard unit of measurement used in Canada by Health Canada, as well as by the World Health Organization (WHO).
- Picocuries per liter (pCi/L): This is the standard measurement used in the United States by the Environmental Protection Agency (EPA).
Quick Conversion Rule: 1 pCi/L is equal to 37 Bq/m³.
The Action Levels: When Should You Worry?
Radon is a naturally occurring gas, meaning there is no such thing as a “zero” radon environment. The outdoor air typically has a background radon level of about 15 Bq/m³ (0.4 pCi/L).
The goal isn’t to eliminate radon completely, but to keep it below established health guidelines. Here is how to interpret your numbers based on Health Canada and international standards:
1. The “Safe” Zone: Below 100 Bq/m³ (Below 2.7 pCi/L)
If your results are in this range, your home is currently considered safe. The World Health Organization (WHO) recommends keeping indoor radon levels below 100 Bq/m³ to minimize health risks. No immediate action is required, but you should still re-test your home every 2 to 3 years, or after any major renovations.
2. The “Caution” Zone: 100 to 200 Bq/m³ (2.7 to 5.4 pCi/L)
If your number falls here, you are above the WHO recommended level but below the Health Canada action limit. Health Canada suggests that while you don’t need immediate emergency mitigation, you should strongly consider taking steps to reduce these levels. Improving ventilation or sealing major foundation cracks can help push your numbers down over time.
3. The “Action Required” Zone: Above 200 Bq/m³ (Above 5.4 pCi/L)
200 Bq/m³ is the official Action Level set by Health Canada. (In the US, the EPA action level is 4.0 pCi/L, which is roughly 148 Bq/m³).
If your long-term test results are above 200 Bq/m³, you need to take action. Health Canada recommends fixing your home within two years if your levels are between 200 and 600 Bq/m³, and within one year if they are above 600 Bq/m³. You should contact a certified radon mitigation professional to install a system.
Short-Term vs. Long-Term Results
When reading your report, it is crucial to note what kind of test you ran. Radon levels fluctuate wildly day to day and season to season due to weather, barometric pressure, and how often your windows are open.
- Short-Term Tests (2 to 90 days): These are great for a quick snapshot or real estate transactions. However, if a short-term test comes back high, you should always follow it up with a long-term test before spending money on mitigation.
- Long-Term Tests (90+ days): These tests (ideally run through the winter months when windows are closed) give you your true, year-round average exposure. You should always base your mitigation decisions on a long-term test.
Your Next Steps
If your results are high, take a deep breath. Radon is a serious health hazard, but it is also a highly fixable problem.
Install a mitigation system, such as active soil depressurization, which uses a fan and pipe system to draw the gas out from under your foundation. These systems are highly effective and can reduce radon levels by up to 99%.
Verify with a long-term test if your high result came from a short-term kit.
Ready to protect your home? Contact Radon Doctors today to schedule a free consultation or get started with a free professional radon test.