title: High radon areas in the Walloon region of Belgium.
abstract: Indoor radon data from Southern Belgium are organised in 35 geological units (GUs), most of which are homogeneous with respect to the radon risk. The percentage of cases above the reference level (400 Bq m(-3); 300 Bq m(-3) in the future) is calculated for these GUs from the observations and from the log-normal distribution fitted to the data. Affected areas are defined as areas with more than 1 % of houses above the reference level. In the north of the region, the old Palaeozoic basement is generally covered by Silesian, Cretaceous and Tertiary rocks, which are unaffected. The affected areas here are hot spots associated with specific Palaeozoic outcrops. In the south, there is generally no cover above Palaeozoic formations, which are often radon affected. The affected areas of Ardenne and Condroz dominate this part, but unaffected areas occur like Famenne and Gaume. About 48 % of the Walloon region is expected to be radon affected.
authors.affiliation: ISIB, Haute Ecole P.-H. Spaak, Rue Royale 150, Brussels 1000, Belgium tondeur@isib.be.
authors.forename: F
authors.initials: F
authors.lastname: Tondeur
authors.affiliation: European Commission, DG Joint Research Centre, Institute for Transuranium Elements, Nuclear Security Unit, Via Enrico Fermi 2749, Ispra, VA I-21027, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cinelli
authors.affiliation: FANC, Ravensteinstraat 36, Brussels 1000, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Dehandschutter
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D000465:Algorithms; D001530:Belgium; D005843:Geography; D055593:Geological Phenomena; D006798:Housing; D011886:Radon / Q000032:analysis*; D012306:Risk
chemical_list: D000396:Air Pollutants, Radioactive; D011886:Radon