Yes, I can take that one.
In our Canadian geology, basically we sit on a whole bunch of rich natural resources, one of them being uranium. Uranium contributes most of the emissions of radon gas. We have geology maps that target where we have areas of high uranium and areas where we don't. Those give you a good proxy to areas that have high radon levels, but one of the major points, though, is really around how your house is built.
You can be in an area with low levels of uranium, but still some uranium, and if your house is poorly built, over time those levels are going to accumulate. You can be in an area with low levels of uranium, but your home, because of the way it's built, will have high levels of radon, whereas you can be in an area that has high levels of uranium, but your house is a good build. A lot of the building codes have a radon mitigation strategy, and there are sump pumps that you can put into your basement so that the air that comes in is vented out—anything coming up from the ground gets vented out. Even if you just open your windows, you can actually get a lot of the radon circulating and moving out.
That's really where it's important. We need to have all the homes tested. Even if the geological map of your area shows that it's a low uranium area, your home itself could have high levels of radon. You can't even look at your neighbour's house. Your neighbour could have a nicely built house that doesn't have much in the basement, has good ventilation, and has low levels of radon. It's very important to target those homeowners and get that individual testing.
There are strategies, though. We did use the Health Canada survey. They sent out 18,000 radon test kits across the country. They found regions that have a lot of homes with high levels of radon, more than you would expect. We can use that. The Canadian Cancer Society, the Canadian Lung Association, and Health Canada are doing targeted strategies in those areas. The interior of British Columbia is one area. There are some areas in Manitoba. Those are communities where there are strategies. You can do it on a community-by-community basis. Sometimes you have to choose the communities you go into first. You can use geological maps or these radon maps.
What we're really focused on is that if we had everybody testing their homes, with 100% test rates and we knew exactly what to do, then we would need people to take action. Some people might cite.... The test itself is relatively inexpensive. Some charities offer it for free. It could be $30 if you buy it from a hardware store. The cost is from what you need to do to get rid of the radon. It could be a simple cost: you need a professional to come in and really look at it. The cost of mitigating it is a potential barrier, but because we have so few people doing it, we don't know how much of a barrier it is right now. The Canadian Cancer Society and our offices are trying to get as many homeowners testing regardless of where they live.