title: Estimation of Groundwater Radon in North Carolina Using Land Use Regression and Bayesian Maximum Entropy.
abstract: Radon ((222)Rn) is a naturally occurring chemically inert, colorless, and odorless radioactive gas produced from the decay of uranium ((238)U), which is ubiquitous in rocks and soils worldwide. Exposure to (222)Rn is likely the second leading cause of lung cancer after cigarette smoking via inhalation; however, exposure through untreated groundwater is also a contributing factor to both inhalation and ingestion routes. A land use regression (LUR) model for groundwater (222)Rn with anisotropic geological and (238)U based explanatory variables is developed, which helps elucidate the factors contributing to elevated (222)Rn across North Carolina. The LUR is also integrated into the Bayesian Maximum Entropy (BME) geostatistical framework to increase accuracy and produce a point-level LUR-BME model of groundwater (222)Rn across North Carolina including prediction uncertainty. The LUR-BME model of groundwater (222)Rn results in a leave-one out cross-validation r(2) of 0.46 (Pearson correlation coefficient = 0.68), effectively predicting within the spatial covariance range. Modeled results of (222)Rn concentrations show variability among intrusive felsic geological formations likely due to average bedrock (238)U defined on the basis of overlying stream-sediment (238)U concentrations that is a widely distributed consistently analyzed point-source data.
authors.affiliation: †Department of Environmental Science and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, United States.
authors.forename: Kyle P
authors.initials: KP
authors.lastname: Messier
authors.affiliation: ‡Division of Water Resources, North Carolina Department of Environment and Natural Resources, 2090 U.S. 70 Highway, Swannanoa, North Carolina 28778, United States.
authors.forename: Ted
authors.initials: T
authors.lastname: Campbell
authors.affiliation: §North Carolina Geological Survey, Division of Energy, Mineral, and Land Resources - North Carolina Department of Environment and Natural Resources, 1612 Mail Service Center, Raleigh, North Carolina 27699, United States.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Bradley
authors.affiliation: †Department of Environmental Science and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, United States.
authors.forename: Marc L
authors.initials: ML
authors.lastname: Serre
mesh_terms: D001499:Bayes Theorem; D019277:Entropy; D005843:Geography; D060587:Groundwater / Q000737:chemistry*; D009657:North Carolina; D011886:Radon / Q000032:analysis*; D012044:Regression Analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D011886:Radon