title: Modeling of geogenic radon in Switzerland based on ordered logistic regression.
abstract: OBJECTIVE
  The estimation of the radon hazard of a future construction site should ideally be based on the geogenic radon potential (GRP), since this estimate is free of anthropogenic influences and building characteristics. The goal of this study was to evaluate terrestrial gamma dose rate (TGD), geology, fault lines and topsoil permeability as predictors for the creation of a GRP map based on logistic regression.
  
  
  METHODS
  Soil gas radon measurements (SRC) are more suited for the estimation of GRP than indoor radon measurements (IRC) since the former do not depend on ventilation and heating habits or building characteristics. However, SRC have only been measured at a few locations in Switzerland. In former studies a good correlation between spatial aggregates of IRC and SRC has been observed. That's why we used IRC measurements aggregated on a 10 km × 10 km grid to calibrate an ordered logistic regression model for geogenic radon potential (GRP). As predictors we took into account terrestrial gamma doserate, regrouped geological units, fault line density and the permeability of the soil.
  
  
  RESULTS
  The classification success rate of the model results to 56% in case of the inclusion of all 4 predictor variables. Our results suggest that terrestrial gamma doserate and regrouped geological units are more suited to model GRP than fault line density and soil permeability.
  
  
  CONCLUSIONS
  Ordered logistic regression is a promising tool for the modeling of GRP maps due to its simplicity and fast computation time. Future studies should account for additional variables to improve the modeling of high radon hazard in the Jura Mountains of Switzerland.
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland. Electronic address: georg.kropat@chuv.ch.
authors.forename: Georg
authors.initials: G
authors.lastname: Kropat
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pré 1, 1007 Lausanne, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Bochud
authors.affiliation: Swiss Federal Office of Public Health, Schwarzenburgstrasse 157, 3003 Berne, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Murith
authors.affiliation: Swiss Federal Office of Public Health, Schwarzenburgstrasse 157, 3003 Berne, Switzerland.
authors.forename: Martha
authors.initials: M
authors.lastname: Palacios Gruson
authors.affiliation: Swiss Federal Office of Public Health, Schwarzenburgstrasse 157, 3003 Berne, Switzerland.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Baechler
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000706:statistics & numerical data; D000398:Air Pollution, Radioactive / Q000706:statistics & numerical data; D008956:Models, Chemical; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D013557:Switzerland
chemical_list: D000396:Air Pollutants, Radioactive; D011886:Radon
keywords: European atlas of natural radiation; Fault lines; Geogenic radon; Ordered logistic regression; Soil permeability; Terrestrial gamma dose rate