title: Analysis of 222Rn concentration in North Carolina household water supplies derived from private wells.
abstract: The objectives of this study were to characterize the concentrations of 222Rn in North Carolina household groundwater supplies and to investigate the relationship between indoor air and groundwater 222Rn concentrations. Measurements of 222Rn in groundwater supplies were performed in 400 North Carolina homes in which a state/Environmental Protection Agency survey had made measurements of indoor airborne 222Rn. The arithmetic mean 222Rn concentration measured in groundwater supplies statewide was 67 Bq L-1 (1,800 pCi L-1), and the geometric mean was 24 Bq L-1 (660 pCi L-1). Sixty-seven percent of the state's homes with wells had 222Rn water concentrations in excess of the Environmental Protection Agency's proposed limit for public drinking water supplies of 11 Bq L-1 (300 pCi L-1). The percentage of homes with water concentrations in excess of the proposed limit was 30% in the eastern region of the state, 75% in the central region, and 83% in the western region. No significant correlation was observed between measurements of indoor air and water 222Rn concentrations in these homes.
authors.affiliation: Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill 27599-7400.
authors.forename: J E
authors.initials: JE
authors.lastname: Watson
authors.forename: J P
authors.initials: JP
authors.lastname: Evans
authors.forename: A M
authors.initials: AM
authors.lastname: Mabry
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis; D000398:Air Pollution, Radioactive / Q000032:analysis; D006798:Housing; D006801:Humans; D009657:North Carolina; D011886:Radon / Q000032:analysis*; D014878:Water Pollution, Radioactive / Q000032:analysis*
chemical_list: D011886:Radon