Joint Analysis of Long- and Short-Term Radon Monitoring Data from the Northern U.S

This paper analyzes data collected as part of two types of radon surveys of U.S. homes-the National Residential Radon Survey (NRRS) and the U.S. Environmental Protection Agency (EPA)/State Residential Radon Surveys (SRRS)-to determine the distribution of annual-average, living-area radon concentrations for ground-contact homes in the northern U.S. A statistical model is used to link the short-term SRRS measurement in each home with the home's annual-average, living-area radon concentration, although in no case are both a short- and long-term measurement available for the same home. This paper shows that, even though an individual short-term winter measurement from the SRRS is a poor predictor of the home's annual-average, living-area radon concentration, an aggregation of such measurements can be used, after adjusting for bias, to characterize the distribution of annual-average, living-area concentrations as determined by the NRRS. Different types of homes require different adjustment equations. This paper presents the adjustment equations and uses them to estimate parameters describing annual-average, living-area concentration distributions. Model approximations and validation are briefly discussed. The methods presented here could be applied to calibrate other radon data sets.