What is it and where does it come from?
Radon is a radioactive noble gas. It is odorless, tasteless and invisible. Radon is measured in Becquerels/meter cubed (Bq/m3). A Bq (Becquerel) is a scientific term describing one radioactive decay per second. 200 Bq/m3 means that there are 200 radioactive radon particles decaying every second in every cubic meter of air.
Radon is a naturally occurring substance found throughout the world. It is created as part of the radioactive decay chain where uranium progressively decays into lead. Uranium can be found almost everywhere in soil, rocks and water. Based on the geology in Alberta we are classified as an area with a potential for high radon levels.
How does radon get into your home?
Radon gas moves through openings in any part of the building that is in contact with the ground. Access points include cracks in your slab and around the perimeter of foundations/interior footings, openings around utility/plumbing penetrations, sump pits and clean outs etc.. If all of these entry points combined total 1 cm2 there is enough space to allow dangerous levels of radon into your home.
Radon gas enters the home because of a negative pressure in the home compared to the outside environment. The pressure difference acts like a very small vacuum cleaner sucking radon gas into your home. This negative pressure is usually due to warmer temperatures in the building compared to the outside and the ventilation systems we use to heat and cool our homes.
Radon gas can also enter your home through water. This is only a potential concern with well water as municipal water treatment plants will have removed the radon before it leaves the facility. Very rarely materials such as the concrete or granite in your home can also emit radon gas into the air.
It does not matter if your house is new or old, or the type of construction used. You cannot tell if you have it based on your neighbour's measurements. The only way to know if you have radon in your home is to test for it.
How do I find out if I have radon in my home?
The good news is that radon is easy to test for. There are many different types of tests and Health Canada recommends a long term test (91 days to 1 year) to measure the actual exposure. If you feel that is too long to wait there are also short term tests that can be performed in less than 3 days while the long term test is ongoing.
The other good news is that if you have radon in your home it can be fixed. Mitigation methods today can almost always reduce the levels in your home to between 75 and 200 Bq/m3. Mitigating your home to reduce the levels of radon is generally less expensive that putting a new furnace in your home.
Some people are concerned that finding radon in your home may decrease property values. In fact radon testing and radon mitigation systems can be a value added feature to your home. As more people become aware of the risks, more people will be asking about it during real estate transactions. If your home has already tested at approved levels it is one less thing for the buyer to worry about. In many parts of the U.S.A. radon testing is mandatory as part of real estate transactions.