Fewer than 91 days in the heating season
If fewer than 91 days of your test fell in the heating season, the result may read low. Test again next heating season.
What is a safe radon level?
Health Canada (opens in a new tab)'s guideline for radon in your home is 200 Bq/m³. If your long-term result is above 200, Health Canada (opens in a new tab) says to lower it. Below that, no level is completely risk-free, so lower is still better.
200 Bq/m³
Health Canada (opens in a new tab)'s guideline. Above it, fix it.
1 pCi/L = 37 Bq/m³
How to read a US result
11%
Of Windsor-Essex homes tested were above 200 Bq/m³ (2015 to 2018)
At least 91 days
How long a test runs to count against the guideline
What does Bq/m³ mean?
Bq/m³ means becquerels per cubic metre. It's the unit for how much radon is in the air, and it's what Canadian results use.
Some kits and monitors, mostly American ones, show pCi/L (picocuries per litre) instead. Health Canada gives 1 pCi/L as 37 Bq/m³, so to read a pCi/L result, multiply it by 37.
Rather not do the math? The radon unit converter (opens in a new tab) on the Canadian Radon Services Index switches a number between pCi/L and Bq/m³.
Is 200 Bq/m³ the line between safe and unsafe?
It's the point where Health Canada says to fix it. The risk goes up the higher your level is and the longer you live with it. Below 200 the risk is lower, but Health Canada says no level is risk-free.
Other places use different numbers, which is why US websites can be confusing. The US EPA (opens in a new tab) says to fix a home at 4 pCi/L or more, which it gives as 150 Bq/m³. The World Health Organization (opens in a new tab) suggests 100 Bq/m³.
What if your result is 200 or lower?
You're at or under Health Canada's guideline. Health Canada leaves it up to you whether to lower it more. Two times to test again:
After a renovation
After a renovation that changes how the house is built or how air moves through it, like finishing the basement or putting in a new furnace. Test again in the next heating season.
Most local homes land here. In the health unit's 2015 to 2018 study (opens in a new tab), 11% of Windsor-Essex homes tested were above 200 Bq/m³. See more on Radon in Windsor-Essex.
What if your result is above 200?
Your number is over Health Canada's guideline, and it can be fixed. My result is high covers how soon to act and what it costs.
Got a result above 200? See what to do nextDoes a short test give you the number that counts?
Health Canada compares only a long-term average with the guideline. A long-term test runs at least 91 days.
Radon goes up and down from day to day and season to season, so a short test is a first look. Short or long radon test explains which one to use.
To check your own result, the Index's result interpreter (opens in a new tab) takes your number, how many days the test ran and how many of those days the heat was on. It tells you if the test was long enough and how your number compares with 200 Bq/m³.
Book a test or ask for a quote
Result above 200? See what to do next. Only have a short-test number? Get a long-term one.
Book a test or ask for a quote
Or call 519-991-8180
Monday to Friday, 9am to 5pm. Saturday by appointment.