title: Large-scale radon hazard evaluation in the Oslofjord region of Norway utilizing indoor radon concentrations, airborne gamma ray spectrometry and geological mapping.
abstract: We test whether airborne gamma ray spectrometer measurements can be used to estimate levels of radon hazard in the Oslofjord region of Norway. We compile 43,000 line kilometres of gamma ray spectrometer data from 8 airborne surveys covering 10,000 km2 and compare them with 6326 indoor radon measurements. We find a clear spatial correlation between areas with elevated concentrations of uranium daughters in the near surface of the ground and regions with high incidence of elevated radon concentrations in dwellings. This correlation permits cautious use of the airborne data in radon hazard evaluation where direct measurements of indoor radon concentrations are few or absent. In radon hazard evaluation there is a natural synergy between the mapping of radon in indoor air, bedrock and drift geology mapping and airborne gamma ray surveying. We produce radon hazard forecast maps for the Oslofjord region based on a spatial union of hazard indicators from all four of these data sources. Indication of elevated radon hazard in any one of the data sets leads to the classification of a region as having an elevated radon hazard potential. This approach is inclusive in nature and we find that the majority of actual radon hazards lie in the assumed elevated risk regions.
authors.affiliation: Geological Survey of Norway, Leiv Eirikssons vei 39, N-7040 Trondheim, Norway. mark.smethurst@ngu.no
authors.forename: Mark Andrew
authors.initials: MA
authors.lastname: Smethurst
authors.forename: Terje
authors.initials: T
authors.lastname: Strand
authors.forename: Aud Venke
authors.initials: AV
authors.lastname: Sundal
authors.forename: Anne Liv
authors.initials: AL
authors.lastname: Rudjord
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D000398:Air Pollution, Radioactive / Q000032:analysis*; D040362:Geographic Information Systems; D055593:Geological Phenomena; D006798:Housing / Q000592:standards; D009664:Norway; D011237:Predictive Value of Tests; D011834:Radiation Monitoring / Q000379:methods*; D011886:Radon / Q000032:analysis*; D013051:Spectrometry, Gamma
chemical_list: D011886:Radon