Geospatial Analysis of the Radon Exposure by Region. Panel A: Administrative map of Canada highlighting survey region provinces, relative population densities relative to study cohort distribution. Cartogram representing the federal electoral divisions in Alberta (blue) and Saskatchewan (green), color-coded by number of radon tests per division. Panel B: Domestic indoor air radon concentrations for buildings split by cities and region. Yellow dots = 0–99 Bq/m3; Orange dots = 100–199 Bq/m3; Red dots ≥ 200 Bq/m3. All dots are 50% transparent to indicate data densities. Panel C: Upper and lower 95% confidence intervals from bootstrapped mean estimates of radon concentration plotted against the resampling size.