Radon in Homes and Other Dwellings
What is radon?
Radon is a colourless, odourless radioactive gas that is released from the breakdown of uranium that occurs naturally in rock, soil, and groundwater.
When released outdoors, radon gas becomes diluted with air and poses little risk. However, radon gas can build up inside homes and other buildings and pose a health hazard. Radon primarily enters buildings through soil, moving through cracks and other openings (construction joints, and gaps around service pipes) in the foundation.
How does radon affect my health?
Breathing in radon over the long-term can cause lung cancer. Health Canada states that radon is the second leading cause of lung cancer in Canada next to smoking. About 16 per cent of lung cancer deaths in Canada are due to indoor radon exposure.
The risk of developing lung cancer depends on both the concentration of radon in the air, as well as the length of exposure. However, studies show that even low levels of radon can cause harm, so levels in a home and building should be reduced as much as possible through remediation. Remediation is the term used to describe the various processes used to reduce the amount of radon in homes and other buildings.
Smokers are at highest risk of developing lung cancer because radon and tobacco smoke have a synergistic relationship. Children are potentially more vulnerable, because they have a longer time in which to develop lung cancer, if exposed to radon early on in their lives.
Experts state that exposure to a radon concentration of 200 Bq/m3 at home, on an ongoing basis over a lifetime, gives a 2 per cent chance of developing lung cancer. For a smoker, the lifetime chance of developing lung cancer is much higher, at around 30 per cent.
Radon exposure does not produce immediate symptoms. You may not realize exposure to elevated levels of radon has occurred until you or someone in your family is diagnosed with lung cancer. For this reason, it is important to test, and if needed, remediate your home for radon.
How is radon measured?
Radon in air is measured in Becquerels per cubic meter (Bq/m3), a measure of radioactive decay per second. Indoors, radon can be measured using both long-term (3 months to a year) and short-term (2 to 7 days) tests. Long-term testing is recommended to provide an accurate measurement of radon concentrations in a home and building. Small wall-mounted radon detectors are used to measure long-term radon concentrations. Other types of radon detectors can be used to conduct short-term tests, but because radon levels can vary greatly over a period of 24 hours, very short-term tests (2 to 7 days) are not recommended.
What are the guidelines levels for radon?
Health Canada recommends that where average annual radon concentrations in dwellings (e.g. homes and other places where people spend 4 or more hours a day) are above 200 Bq/m3, remediation should be conducted.
Radon in B.C.
Radon sampling has been conducted in more than 22 B.C. communities to monitor radon concentrations and to identify radon-prone areas of the province.
Sampling results in the Interior and east of the Coast Mountain Range showed that between 5 to 40 per cent of dwellings may have radon levels of more than 200 Bq/m3, depending on the community. Elevated levels of radon were also found in the North. Coastal regions had fewer dwellings over 200 bq/m3.
Should I get my home tested?
Everyone is encouraged to test their home for radon. Radon levels vary widely from house to house, even in the same neighborhood. This is because concentrations in a building depend on several factors, including the geology of the area, housing construction, and characteristics like air exchange in the home.
Newer dwellings that are tightly sealed tend to have higher radon levels. In general, radon concentrations tend to be highest in the lowest levels of a building, including basements.
The only way to be absolutely sure of the concentration of radon in your home is to test. Those living in Interior and Northern communities in B.C. are especially encouraged to test their homes for radon.
How do I get my home tested?
Radon testing is easy, relatively inexpensive, and can be done with “do it yourself” tests. A long-term radon detector, which can be obtained from several places, is placed in the lowest level of your home that is occupied for more than 4 hours per day.
Specific instructions are provided with the detector. Once the test is completed (ideally over a period of 3 months to 1 year, including some winter months), the detector is mailed to a lab for analysis. The lab then provides the testing results, in the form of an average radon concentration over the test period. This level can then be compared to Health Canada’s guideline of 200 Bq/m3. Because no level of radon is considered to be without harm, individuals are encouraged to consider remediation, even if levels are close to or below the guideline.
A list of suppliers of radon testing devices is available from the BC Centre for Disease Control (BCCDC) at www.bccdc.ca/healthenv/Contaminants/Radon/default.htm, or under ‘home inspection services’ in your local phone listings. The cost of a testing device and results is about $50.
Test kits are also available from:
- BC Lung Association - Call 604-731-5864, toll-free 1-800-665-5864 or e-mail firstname.lastname@example.org.
- Northern Health Authority – Call 250-565-2150, toll-free 1-800-663-7867 or email email@example.com.
- Donna Schmidt Memorial Lung Cancer Prevention Society. Call 250-365-0344 ext 227 or email firstname.lastname@example.org. Note: Kits are limited to locations in the Kootenays.
What can I do if tests show my home has elevated radon levels?
There are several things you can do to greatly reduce the levels of radon in your home:
- Ventilate the basement sub-flooring by installing a small air pump to draw the radon from below the concrete slab and vent it outside before it enters the home or building.
- Improve ventilation or air flow (natural or forced) of crawl spaces, basements and other areas on the lower levels of the home or building by opening windows or using ceiling fans.
- Seal cracks and openings in basement floors and walls, and around pipes and drains.
Certified radon mitigation professionals are available to provide advice and conduct remediation. To find a radon professional in your area, visit the Canadian-National Radon Proficiency Program (C-NRPP) web page at www.c-nrpp.ca/.
After remediation is completed, another radon test should be done to ensure that levels have been reduced.
What changes are being made to address radon?
Both the federal and provincial governments continue to explore ways to prevent or reduce radon levels in buildings. For example, the BC Building Code requires new buildings in radon-prone areas of B.C. to install radon provisions that help to address indoor radon concentrations.
For More Information
For more information, please contact your local health authority environmental health officer by visiting www.health.gov.bc.ca/socsec/.
Or by phone at:
- Vancouver Coastal Health 604-736-2033
- Island Health 250-370-8699
- Interior Health 250-862-4200
- Fraser Health 604-587-4600
- Northern Health 250-565-2649
For more additional information, contact:
- Environmental Health Services Division, BCCDC. Call 604-707-2443, or visit www.bccdc.ca/healthenv/.
- National Collaborating Centre for Environmental Health (NCCEH), Call 604-707-2445 or visit www.ncceh.ca