What is Radon?
Radon is a radioactive gas that you cannot smell or see. It is naturally occurring, and is created as uranium in soils and rocks decay. Radon from the soil and bedrock can seep into the home through cracks in the foundation, floor drains and other openings. Radon is heavier than air so as it accumulates in the home, it may build up to unsafe levels.
When radon is inhaled it damages the lung cells and can lead to lung cancer. RADON EXPOSURE IS THE SECOND LEADING CAUSE OF LUNG CANCER, next to tobacco smoke.
How to Test your Home for Radon
There has been some radon testing of homes in the North. Results show that elevated levels of radon (200 becquerels/m3 or more) have been detected in the North, particularly in areas east of the Coast Mountains.
Radon levels can vary from home to home and from season to season. In some cases radon levels may be higher in newly constructed homes that are well sealed compared to older draftier homes.The only way to know whether the home has elevated levels of radon is to test for it.
Reducing High Levels of Radon
If an existing home has elevated levels of radon there are a number of steps that a contractor or homeowner can take to reduce these levels, including:
- Prevent the entry of radon. This can be as simple as sealing cracks and openings in the home or installing equipment that will ventilate the basement sub-flooring.
- Increase the air exchange in the home. A heat recovery ventilator allows the exchange of air while preserving the temperature of the home.
- Renovate existing basement floors, particularly earth floors.
Health Canada recommends that mitigation be done by an experienced contractor. There is currently no certification program for mitigation contractors in Canada, though Health Canada is in the process of developing one. At this point, Health Canada recognizes the mitigation certification programs offered through the US National Environmental Health Association or the US National Radon Safety Board. Web link to course list is posted below.
Radon Resistance during new Construction
It is difficult to accurately determine the indoor radon gas concentrations prior to construction of a new home. However, using common materials and simple techniques, builders can construct homes that are resistant to radon entry.
The National Building Code has been recently revised and now includes the requirement for new homes to have measures that prepare a building for the prevention of radon soil gas entry into the home. This technique is commonly known as sub-slab depressurization. It involves roughing-in a pipe through the foundation (see example diagram below) and if it is determined that radon levels in the home are elevated this pipe can be used to vent radon gas directly to the outside of the home.
Building radon resistant homes is cost-effective and protects the homeowner’s health. The cost of building a radon resistant home is generally much lower than the cost of mitigating an existing home. Also, by building radon resistant homes, builders and contractors are helping to reduce the homeowner’s risk of lung cancer from radon exposure.