Uranium is everywhere, in all kinds of soil, and when it breaks down it produces a radioactive gas that is odourless, colourless and tasteless. This gas is radon.
When radon gas is released into the atmosphere, it gets diluted. But if it finds its way into your home it can accumulate into higher concentrations, and that's when it can become dangerous.
Being exposed to high doses of radon over a long period of time is a major health risk. According to Health Canada, radon gas is linked to about 16 percent of all lung cancer deaths in Canada. That makes radon the second leading cause of lung cancer; first for non-smokers.
Being a smoker significantly increases a person's risk of developing lung cancer if they are also exposed to elevated levels of radon. For example, people who are only exposed to radon have a 1 in 20 chance of developing lung cancer whereas those who are also smokers have a 1 in 3 chance.
Radon is a gas, so it can easily seep into your home through floors, pipes, windows, sumps and cracks in foundation walls. But it can even penetrate through foundation walls because concrete is porous.
The only way to know if your home has a radon problem is to test for it. One house can have radon levels next to zero while the house next door can be off the charts.
These levels also fluctuate depending on the weather, humidity and even time of year.
For example, during the winter when windows and doors are kept shut for the most part, radon can accumulate in the home. This is why radon levels tend to be higher in the winter-and for that same reason, why winter is the best time to test for radon.
There are short-term and long-term radon tests. A short-term test can last anywhere between 2 - 7 days, whereas long-term testing can last as long as 365 days.
Due to the fluctuations in radon levels, long-term testing provides a more accurate indication of a home's average year-round radon levels. For this reason Health Canada recommends long-term radon testing.
Specific requirements must be followed when testing for radon. For example, all windows and doors must be kept shut as much as possible during the full duration of the test. This is why some homeowners choose to have their home tested while they are away.
Reducing radon levels in a home can cost anywhere between $500 and $3,000. Some solutions involve installing a cap on sump pumps, or boosting up the ventilation in the home with something like a heat recovery ventilator (HRV), or sealing cracks in the foundation and around pipes and drains. Sometimes these solutions are enough, but other times they're not.
The most effective way to reduce radon levels in a home is through a process called sub-slab depressurization. It involves drilling a hole through the basement floor (concrete slab) and installing a pipe with a fan. The fan draws radon gas from the ground and expels it through the pipe to a vent, usually located on the roof of the home.
If your home requires radon mitigation, make sure you hire a contractor who is certified by the Canadian National Radon Proficiency Program (C-NRPP) and who has plenty of experience reducing radon levels in residential construction.