Radon Gas Awareness: Knowledge Is Lifesaving
Many clients have asked me about radon gas because of multiple media reports lately on the toxicity of indoor radon gas. Questions clients have asked include what is it, how much is too much and why should I be concerned? As well, how does it get into my house and how do I test for radon? Health Canada has produced a radon map and confusion occurs because Vancouver doesn’t show up as an area affected by radon. So let’s look at what radon is and why it may be prudent for homeowners to have their homes tested.
You can’t see it, you can’t smell it and you can’t taste it.
Radon takes the form of a radioactive gas produced naturally when the uranium in soil and rock breaks down. Typically, radon in the ground releases in an outdoor environment where it dilutes, thus avoiding a health concern. When is it dangerous? It becomes dangerous when released into an enclosed area such as the basement or a house crawlspace. In homes it can accumulate into high concentrations and in these areas it can be deadly.
What does this harmful radon gas do?
Radon gas is the creation of radioactive decay. Consequently, when people inhale it into their lungs it allows radioactive elements to develop into harmful particles that further decay. These decaying particles damage the lung tissue and cells. Damaged cells are prone to developing cancer when they reproduce. So exposure to radon for a long period of time will increase a person’s risk to developing lung cancer.
Any smokers in the home?
Lifelong smokers usually have a 1 in 10 chance of developing lung cancer; add radon into the mix and that statistic rapidly changes to a 1 in 3 chance of developing lung cancer (¹). Nevertheless, even if you have never smoked a day in your life, if exposed to high levels of radon for an extended period, you have a higher chance of getting lung cancer.
How does it get into my house?
Houses have air exchanges that are constantly occurring. The interior air pressure is normally lower that the air pressure found in soil. When the foundation walls and slab of a home are not continuous, meaning there are gaps or voids in these areas, a negative pressure situation can occur. What this means is the lower air pressure in the interior of the home acts like a slow vacuum that readily draws in air and gases (like radon) into the home. Look at the diagram below for examples of gaps or voids found in most homes:
Where does radon come from?
Since radon naturally exhausts out of bedrock and soil, you may find it in many homes across the country. Does Vancouver have radon? There have been homes recorded with high concentrations levels. A basic rule of thumb in the inspection industry is that if your home is constructed on rock. Then you will most likely find elevated levels of radon. Therefore, if you have a basement you will stand an even better chance of having radon issues. Homes built into mountains are more prone to this issue, for example North and West Vancouver or homes up in the Burke Mountain area of Coquitlam. As always, concentration levels will vary from home to home. Ultimately, the only certain way to tell if a home is in need of mitigation is to TEST the house for radon, regardless of the location.
What is a high amount of radon?
Current Canadian guidelines state a dangerous amount of radon gas has a rating of 200 Becquerel per cubic meter (200Bq/m3).
- A Becquerel is a measurement of a unit of radioactive decay equal to one disintegration per second.
A home with a rating of 200bq/m3 or above should have the levels reduced through mitigation by a licensed professional radon company.
How do I test for radon in my home?
There are currently two ways to test radon levels in houses.
- The first is a “do-it-yourself” kit which you can order by phone, on the internet or at your local home renovations store. If you choose this option, be sure to follow the instructions of the kit very closely. Also, make sure when you purchase the kit that it includes the fee for laboratory analysis. In many cases it doesn’t. To get realistic estimates, do the test at the lowest “lived in” level of the home. “Lived in” means an area that is occupied for more than 4 hours per day, as time of exposure to radon is a big factor in its potential negative effects.
- Hire a radon measurement professional. If this is the direction you decide to take, make sure to ask the person for proof of their certification. As of 2012 you can find Canadian radon professionals through the “Canadian – National Radon Proficiency Program” or C-NRPP at c-nrpp.ca. Ensure that they recommend and conduct a long term test for minimum of 3 months.
Bottom line, build on bedrock and radon could be present.
Areas in the interior of the province have a long history of radon. However, lately some homes in the lower mainland and North Vancouver have recorded high radon levels. I recommend that if your home on bedrock or near a mountain range, you should test for radon. Finally, often if a test detects high levels of radon correction costs are not highly expensive, especially compared to the overall value of your house and your life!
Author: Geoff Bohaker at Shelter West Home Inspections