Indoor Air Quality/RE: radon testing


Hello Stephen,

I live in an old triplex which was built in the 60s.
Recently it was advertised that consumers ought to test their basement for radon. My basement is partitioned into two. One side has tile flooring (where the leisure room, a bedroom and bathroom are located) while the other side is concrete (where the water tanks and other necessities are stored). I plan to buy a radon test kit. That being said, what key area(s) of the basement do I need to put radon tester? Will I need to buy more than one?

Thank you for reading.

Montreal, Quebec,Canada


If you occupy the basement, then test the basement in the occupied area. If you also occupy the first level above the basement, then I recommend testing that level as well.  

An inexpensive way to test for radon is with a charcoal absorption kit.  These use porous carbon that "grabs" radon particles and holds them, allowing a laboratory to analyze the radon concentration in air.

Obtain kits from an approved laboratory, such as or  Sometimes local health departments provide them for free or for a reduced rate.  It is important to follow the kit instructions.  They are normally left out in the open to collect the sample for 2-4 days.  Be sure that doors and windows in the space are kept closed, as excess fresh air can greatly reduce the measured level.  Also, winter is often the time when levels are highest, because many fuel burning appliances (such as a furnace) are drawing combustion air from the indoor space and causing a slight suction effect in the soil and gravel surrounding the foundation.  

Ideally, you should run a test in the heating and the non-heating season.  

Keep track of the "open time" of the sensor, to the minute.  This information is critical for an accurate result.  

Another option is to have as long-term sensing device placed in your home.  This will provide a continuous readout of radon levels and fluctuations over a long period (3 months or more).  This is a more expensive option, but it gives better data.    

For more information read these sites:

If your levels are elevated, then you should have a radon mitigation system professionally installed.

Best of luck, and let me know if you need additional information.

Steve Major  

Indoor Air Quality

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Stephen Major (Principal--Lakeland Environmental)


I can answer questions on indoor mold, indoor air quality, asbestos, and indoor moisture problems. This includes mold testing and mold remediation. PLEASE indicate your state or region, so I can provide the best possible answer.


I have extensive experience in the investigation, testing, and remediation of indoor fungal (mold) infestations, including the design and oversight of remediation projects, hands-on cleaning and removal, and safe work practices. I developed a successful mold remediator training and certification program, and have trained many mold workers and remediation supervisors in proper techniques. I have a strong knowledge of the ways in which moisture and airlow patterns in buildings can affect fungal growth and air quality.

BS Cornell University. IAQA Certified Mold Remediator. 40-hour HAZWOPER certification. NYS Department of Health Certified Training Director.

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