Testing Your Facility for Radon
Testing for radon is a relatively simple procedure when testing a single family dwelling but is more complicated when testing a larger building such as a school or an office building.
Considerations in establishing testing protocols include occupancy patterns within rooms and the proximity of the device to the floor, walls, ceiling, other objects and mechanical systems in the test area.
It is recommended that certified radon professionals registered with either the Canadian National Radon Proficiency Program (C-NRPP) conduct the testing.
Short- and Long-Term Radon Testing
Long-term radon tests range from 91 days to 1 year in length and short-term tests typically take from 2 to 7 days. Radon concentrations can vary significantly in a building from hour to hour, day to day and even more so from season to season. As a result, long-term tests are better at estimating the annual average radon concentration in a building. Health Canada recommends that long-term testing be used to determine if radon levels in a building exceed the national action level and if remedial actions are required. Health Canada’s action level is 200 Becquerels per cubic metre (Bq/m³) which is a measurement of radiation associated with radon.
Long-Term Testing Ensures Accurate Results
As indicated, long-term testing is the best method to determine the annual average radon level in a building. A minimum test duration of 3 months (i.e. > 91 days) during the heating season (fall/winter) is recommended. A 3 month test should be used to determine mitigation requirements and is also indicative of a person’s annual average exposure to radon in a building.
Short-Term Testing for a Quick "Snapshot"
If results are required quickly, a short-term test can offer a snapshot of radon levels in the building. A short-term radon test is typically conducted over a period of 2 to 7 days. However, Health Canada advises that a short-term test should not be used as a means to determine if a building requires radon mitigation.