Radon is usually highest in basements, so a basement unit is the first place to test. Tenants and landlords can both test. A long-term test of at least 91 days gives the number to compare with Health Canada (opens in a new tab)'s guideline.
No Ontario law requires landlords to test for radon, but the general duty to keep a unit in good repair still applies. A tenant can take a concern to the Landlord and Tenant Board (opens in a new tab). (source) (opens in a new tab)
200 Bq/m³
Health Canada (opens in a new tab)'s guideline. Above it, fix it.
At least 91 days
How long a long-term test runs
About $50
A long-term test kit, per the health unit
4+ hours a day
Test the room you use this much
Radon comes up from the soil. Health Canada says levels are usually highest in basements and crawl spaces.
People sleep down there and spend hours a day there. Health Canada says to test the lowest level you live on, in a room someone uses more than 4 hours a day.
Essex County Library (opens in a new tab) lends a digital radon monitor for up to 3 weeks, usually in the colder months. It's a short look, not a long-term test. We haven't confirmed whether City of Windsor residents can borrow one.
For the number to compare with Health Canada's guideline of 200 Bq/m³, use a long-term kit. It runs at least 91 days, and the health unit says it costs about $50.
Tell your landlord the result in writing, so there's a record. (source) (opens in a new tab)
No Ontario law requires landlords to test for radon. The general duty to keep a unit in good repair still applies (Residential Tenancies Act, 2006, s. 20).
We don't give legal advice. For your situation, talk to a lawyer or a paralegal. The Landlord and Tenant Board is where a tenant files.
The same as any homeowner: put in a radon mitigation system. Our page on what to do with a high result covers the next steps, and our mitigation page shows how a system works.
Test again after the fix to check it worked. Our guide to short and long tests explains which test to use.
Tell us about your home, and send your result if you have one.
Or call 519-991-8180
Monday to Friday, 9am to 5pm. Saturday by appointment.