The annual radon average one hour is not the guideline
The Canadian guideline speaks of an annual average concentration. Radon moves every day: higher at night and in winter, lower with the windows open. A one-hour snapshot is not that average. A 91-day test during the heating season comes closer, because it covers the time when the house is closed and exposure is highest.
Health Canada sets the minimum at three months. A shorter test answers a real-estate deadline. Name it for what it is. Two numbers. Dosimeter or monitor.
Reference points: Health Canada, what you need to know about radon and the 200 Bq/m³ guideline. The two-year timeline between 200 and 600, and one year above 600, comes from Health Canada’s guide for radon measurements in homes.
The 4-day test gives a first reading. The 91-day test covers the three-month minimum Health Canada asks for. Both are $59 before tax: shipping, return and the laboratory are included, taxes extra. The PDF report is sent within 2 business days after the laboratory receives the detector.
Above 200 Bq/m³, mitigation is confirmed with a quote. Gaz Radon is C-NRPP certified for measurement and mitigation.
Sources
