My wife would be very pleased to see this thread on CP. She's the program coordinator for radon awareness for Ontario
It doesn't get a lot of attention as tobacco is what people usually associate with lung cancer.
The danger with it is long term exposure. Because it's a gas that arises from rock, the concern if you spend a lot of time in an area the gas can collect and concentrate, such as a basement or basement suite. You can get a kit from home Depot and test areas where you spend time regularly. Leave it there for 3 months, and send it off to the lab for results.
If you do have high levels in the home, it can be rectified by installing a fan pipe in the basement to vent the gas outside.
She had a lot of fun working with Mike Holmes on the PSA, and hopes it reaches a lot of Canadians.
I can relay any questions you might have on radon to her.
LChoy