Associations of Indoor Home Radon Levels with Marcellus Shale Development

Background: Radon causes around 21,000 lung cancer deaths annually in the United States. Most exposure occurs in the home when radon gas infiltrates from rocks and soils through openings. Recent drilling and hydraulic fracturing activity in Pennsylvania may have created new pathways allowing entrainment of radon into homes in a state where many homes already exceed the Environmental Protection Agency (EPA) action level of 4piC/L. Aims: To evaluate associations of proximity to Marcellus shale wells, by stage of development, with home radon levels. Methods: We located Marcellus shale wells and homes with indoor radon level readings using Pennsylvania Department of Environmental Protection data from 2006-2013. We used multilevel linear regression with a random intercept for home to assess associations of proximity to Marcellus shale in various stages of drilling with home radon levels while accounting for potential confounders (season of year, home type [e.g. duplex, apartment], area of home tested [e.g. bas...