Winter in Canada … a time for skiing, skating, sliding, tubing, snowshoeing, snowmobiling, polar bear dips and chalets. It’s also a time when levels of indoor radon concentration can significantly increase (watch for our upcoming Radon 101 post!). Radon which would normally escape from the ground into the atmosphere, is trapped by snow cover and frozen ground. Building doors and windows are usually kept closed – reducing natural ventilation. The requirement for indoor heating