How to detect radon in a house

Don’t rely on the results of your neighbour’s house or the average in your neighbourhood, as there are often significant differences from one home to the next.

Radon detectors and other testing instruments

You’ll find radon detectors: 

• Online at the CAA-Quebec Boutique; 
• At one of our 13 Travel Centres; 
• On the Quebec Lung Association website; 
• At some hardware and big box stores 

There are several types of radon detectors available. We recommend using a long term test kit (between 3 and 12 months), as short-term tests (2 to 7 days), such as activated charcoal tests, don’t provide an accurate measurement of radon levels in a home. 

Note that radon concentrations are generally higher during the winter, when windows and doors remain closed and ventilation is minimal. This is the best time to conduct your test. 

Health Canada recommends alpha-track detectors. Each alpha track device can be used to test over a period of 3 to 12 months, after which you send it to the U.S. for analysis. Expect shipping costs and allow an average of two weeks for results.

There are a few other models on the market, some of which are sold for less in big box stores, but only the two models shown in the previous table have been tested by the Consumer Reports team (an independent consumer information organization).

Good to know: Follow the manufacturer’s instructions exactly to ensure reliable results. The test itself is not complicated. Simply install it in the appropriate location in your home and then send it to the lab for analysis.

Other types of measuring devices, less known to the general public, are used mainly by professionals: the electret ion chamber, digital monitors, and continuous monitors. These detectors can be used for short- and long-term testing.  

Where should you install a radon detector?

If your basement or part of your basement is occupied for more than four hours each day (bedroom, family room, or office), that is where you should test. If your home does not have a basement or if the basement is rarely occupied, test on the ground floor instead. 

Place the detector on a desk, table, or shelf: 

• Approximately 40cm from an inside wall or 50cm from an outside wall 

• Between 0.8m and 2m from the floor, but at least 50cm from the ceiling and 20cm from any other object to ensure normal airflow around the detector 

Be sure to make a note of the installation date so that you can fill out the report that you’ll be sending to the lab. Good to know: Does the detector feel like more clutter in an already crowded room? You can hang it from the ceiling with rope and adjust the length of the rope according to the parameters described above. That way it will be out of the reach of young children and pets.  

Where not to install the radon detector

• Kitchen 

• Laundry room 

• Bathroom 

• Closet or cabinet 

• Sump pit, crawl space, or foundation recess 

• Near heating, ventilation, or air conditioning ducts 

• Near doors, fans, windows, or chimneys 

• Near any electrical or electronic equipment 

• In direct sunlight 

Where do I send the radon test for analysis?

Your detector will come with all the instructions for sending it to a laboratory for analysis. Simply package the dosimeter with the materials provided and send it to the lab. Your test results will be returned to you within a few weeks.