Q1. I heard we don't have radon in Alberta?
A1: Until we tested our home we had heard the same thing. Now we know better. In fact due to the geology of the area we are in a high potential location for radon. The glaciers that flowed from northern Canada and Alaska down to the mainland States ground up, moved and spread the naturally occurring uranium across our province. These porous glacial tills also allow for pathways so that the gas can make its way up to the surface where our homes are built.
In addition because of our cold climate we are actually at a higher risk of breathing in the radon gas since we spend more time in our homes than people in warmer climates.
In our colder climate we build our homes with tighter envelops and do not leave windows and doors open for much of the year. This also reduces the amount of fresh air that enters our home which would help dilute the radon gas to lower levels.
The third reason we are at a higher risk of breathing in radon in our climate is because for much of the year we heat our homes to a warmer temperature than the outside environment. This draws more of the radon gas out from under our homes inside where we breathe it. This process is known as thermal stack.
Among the homes that we have tested in Calgary and the surrounding area over 42% of the homes measured levels above Health Canada's action level. The highest reading found was 3500Bq/m3.
Q2: What are the health risks of radon?
A2: At this point in time the only health effects that radon has been proven to cause is lung cancer. There are ongoing studies across the world looking at elevated levels of radon and other cancers and neurological diseases but at this time no links have been confirmed.
Q3: My neighbour's house didn't have high levels of radon so I won't either right?
A3: Unfortunately this is not true. The only way to know if you have high levels of radon is to test.
The minerals decaying that cause radon only affect areas 10 meters within the source point. You may have a "hot rock" under your home and your neighbour may not. This is especially true since the nature of the geology in Alberta where rock has been moved around by the glaciers.
Also your house may have easier access points for the radon to enter or different ventilation flows which will change the levels of radon found in your home compared to your neighbours.
Q4: Can drinking water with radon in it be dangerous?
A4: Cell linings in the stomach help protect us from the radon so ingesting radon through the water you drink is a low health risk. However as water is used in your home it may release the radon in the water into the air that you breathe. The general rule is a 10 to 1 ratio of water to air. This means that radon levels in water of 10 Bq/m3 would increase your air radon levels in your home by 1 Bq/m3. This is normally only an issue with well water as water treatment plants agitate the water in the facility where is dissipates before being moved to your home.
Q5: Radon will decrease my property value so I don't want to know about it.
A5: As awareness grows and radon becomes as well understood in Alberta as it is in other provinces and the States radon testing will become the norm in real estate transactions. If you do find high levels of radon in your home it is simple and economical to fix in most cases. Once the radon has been mitigated it can actually be a selling feature for your home.
Q6: New houses don't have radon in them do they? My house is old and drafty so I shouldn't have a problem right?
A6: All houses need to be tested regardless of construction type. For example new houses have tighter envelopes that can trap the radon inside but older houses can have poor quality foundations that allow more gas to come into the home. You just never know without testing.
Q7: How do you test for radon?
A7: Testing for radon is a simple and inexpensive thing to do. Kits can be purchased online or in your local hardware store. Certified professionals can also be hired to perform the tests for you. Different types of tests measure the radon in different ways. Health Canada recommends three different types of test – The E- PERM, alpha track or a commercial grade continuous monitor. There are long term and short term tests. Health Canada recommends the long term tests which take from 91 days up to 1 year and show your actual exposure. For more accurate results the best time to test is during the heating season. Short term tests can also be performed to show the potential for radon in a home. These tests usually take 2 days to 1 week but can be as long as 90 days. Short term tests require that your home stay "closed" 12 hours prior and during the entire test. This means windows and doors are closed, fans and some other types of air exchangers must be off.
Q8: Can I test myself?
A8: Yes you can do testing yourself or you can hire a certified professional to perform the test for you. However there are some benefits from purchasing tests through certified radon specialists such as the quality control requirements that ensure the tests have been stored properly and have not been contaminated with background radiation. If you do buy the test at your local hardware store ensure the expiry date has not passed. Check to see what the shipping costs and lab fees are.
Q9: I heard granite countertops emit radon. Should I have mine removed?
A9: It is very rare that items in your home are emitting enough radon to be the cause of the high levels. Though granite is a natural mineral and some types of granite do contain uranium, in 2010 Health Canada preformed radon tests on a number of different types of granite and none were shown to have levels that were of concern. The majority of radon in your home comes from the soil gas under the building. The first thing you need to do is to test your home for radon. If the levels are high, standard mitigation methods to decrease the pressure under the slab will more than likely reduce the radon to acceptable levels.
Q10: If I have radon in my house how do I get rid of it?
A10: The good news is that there are proven techniques to reduce radon levels in your home. The most common and effective method is sub slab depressurization. The goal is reverse the flow of gas into your home by changing the negative pressure to a positive pressure in relation to the area below your home. The cost of these mitigations is usually less that installing a new furnace.
Q11. I have an eco-efficient house so I won't have radon right?
A11: The type of construction used and the age of the home have no direct link to whether or not there is radon in your home. Even if a home has been constructed using the most up to date radon resistant technologies radon testing is recommended every two years.
Q12. I have had an air quality test in my home so I don't need to test for radon right?
A12: Maybe. Your tests results would need to indicate that radon testing had been performed. Radon testing requires specific tests and many air quality tests do not include radon specific testing so make sure you check.
Q13: Are there any safe levels of radon?
A13: Radiation risks follow the linear no threshold model. No radon levels are safe however the risk changes based on exposure duration and dose. This means that low exposures for a long amount of time can be just as dangerous as high levels for a short amount of time. E.g. The risk of lung cancer at 1 Bq/m3 for 10 years is the same as 10 Bq/m3 for 1 year.
Q14: How often should I test?
A14: Health Canada recommends testing every 2 years, after the completion of any renovations or anytime you make changes to your heating or cooling systems. There are many different reasons that radon levels in your home could change over time. For example as the ground freezes and thaws foundations can move and cracks can develop creating new paths for radon gas to enter your home. A total combined open area of 1 cm2 is all that you need to have high radon levels in your home.