Associations of Indoor Home Radon Levels with Marcellus Shale Development

Abstract

Associations of Indoor Home Radon Levels with Marcellus Shale DevelopmentAbstract Number:2487 Joan A. Casey*, Joseph DeWalle, Paul A. Locke, and Brian S. Schwartz Joan A. Casey* Johns Hopkins Bloomberg School of Public Health, United States, E-mail Address: [email protected] Search for more papers by this author , Joseph DeWalle Geisinger Health System Search for more papers by this author , Paul A. Locke Johns Hopkins Bloomberg School of Public Health, E-mail Address: [email protected] Search for more papers by this author , and Brian S. Schwartz Johns Hopkins Bloomberg School of Public Health and Geisinger Health System, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: 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. basement, first floor], and geologic types).Results: There were 399,163 radon tests in 232,726 homes from 2006-2013. The median radon level was 3.3piC/L (interquartile range, 1.5 to 7.4) and 47% of homes had at least one radon reading over the EPA action level. On average, each home had 1.7 readings. There were 6973 Marcellus wells drilled in 39 of the state’s 67 counties over the study period, with 97% drilled after 2008. We will estimate exposure by the proximity of the closest drilled and stimulated well at the time of radon measurement and by an inverse- squared gravity model that will take into account all drilled and stimulated wells in the study area. Multilevel models will be used to estimate associations between the timing of Marcellus shale drilling and fracturing and concurrent indoor home radon level measurements.Conclusions: This research will inform upon potential radiation exposures due to hydraulic fracturing.