I only learned about this when buying a house and the inspector asking if I wanted to pay to have the test done. It came back positive and I disclosed the results to the seller, and in my state it requires them to mitigate before selling. My second house already had a system installed, but we also sleep on a second floor. I have always wondered how good the mitigation is; is Canada behind on public safety of this issue? Are Radon-related cancers on par in states with more regulation/mitigation?
Colorectal is an interesting case as we are already at a place where, by using current screening techniques in a well targeted manner we could essentially eliminate it.
As such, different approaches, or funding, or attitudes to screening could also lead to big disparities in incidence and ultimately survival.
Exposure to Radon is the #1 cause of lung cancer on non-smoker. Canada ranks third on indoor radon concentration worldwide.