Background: Radon is the second-leading cause of lung cancer worldwide. Most indoor exposure occurs by diffusion of soil gas. Radon is also found in well water, natural gas and ambient air. Pennsylvania has high indoor radon concentrations; buildings are often tested during real estate transactions with results reported to the Department of Environmental Protection (PADEP).
Objectives: To evaluate predictors of indoor radon concentrations.
Methods: Using first floor and basement indoor radon results reported to the PADEP between 1987-2013, we evaluated associations of radon concentrations (ln-transformed) with geology, water source, building characteristics, season, weather, community socioeconomic status, community type and unconventional natural gas development measures based on drilled and producing wells.