Radon Map of Switzerland

Transcription

1 Radon Map of Switzerland Experience in Switzerland

2 Current Radon Map 2

3 Radon measurements (in living spaces) 3

4 Radon Map

5 Classification of communities Mean value of the community, based on the annual average of all measured dwellings: Rn < 100 Bq/m Bq/m 3 Rn < 200 Bq/m 3 Rn 200 Bq/m 3 = low risk area = medium risk area = high risk area 5

6 Consequences of the community based classification Canton Basel-Land Canton Neuchâtel 6

7 Misinterpretation of the radon map a specific buildings cannot be evaluated using the radon map neighboring buildings can exhibit very different radon situations the map can lead to a false sense of security 7

8 New situation >1000 Bq/m 3 >300 Bq/m 3 Radon prone areas Alps & Jura ~2% of dwellings ~1% of new dwellings All Switzerland is concerned! ~12% of dwellings ~6% of new dwellings 8

9 New map, the entire country is a radon prone area 2% 12% 9

10 New Radon Map new approach Project by Georg Kropat Institute of radiophysics, Lausanne, Switzerland Kropat, G., Bochud, F., Jaboyedoff, M., Laedermann, J.-P., Murith, C., Palacios, M., Baechler, S., 2014 Major influencing factors of indoor radon concentrations in Switzerland. Journal of Environmental Radioactivity 129, 7 22 Kropat, G., Bochud, F., Jaboyedoff, M., Laedermann, J.-P., Murith, C., Palacios (Gruson), M., Baechler, S., 2015 Predictive analysis and mapping of indoor radon concentrations in a complex environment using kernel estimation: An application to Switzerland. Science of the Total Environment 505, Kropat, G., Baechler, S., Bailat, C., Barazza, F., Bochud, F., Damet, J., Meyer, N., Palacios (Gruson), M., Butterweck, G., CALIBRATION OF THE POLITRACK SYSTEM BASED ON CR39 SOLID STATE NUCLEAR TRACK DETECTORS FOR PASSIVE INDOOR RADON CONCENTRATION MEASUREMENTS. Radiation Protection Dosimetry 167, Kropat, G., Bochud, F., Jaboyedoff, M., Laedermann, J.-P., Murith, C., Palacios (Gruson), M., Baechler, S., 2015 Improved predictive mapping of indoor radon concentrations using ensemble regression trees based on automatic clustering of geological units. Journal of Environmental Radioactivity 147,

11 More criteria to construct the radon map radon measurements lithology (geology) clustering of geological units meteorological data machine learning modeling multidimensional analysis 11

12 Radon measurements ~ measurements ~ houses 12

13 Lithology 70 classes 13

14 Generalized lithological classes Mean of indoor radon concentration in Bq/m Carbonate Rock Alps Carbonate Rock Jura Igneous Rock Metamorphic Rock Sediment Rock class Sedimentary Rock 14

15 Creating artificial classes 15

16 Modeling housetype categorical variables continuous variables altitude model prediction radon concentrations 16

17 Probability mapping 17

18 Radon probability map Future improvements: more variables: uranium content of the ground soil gas measurements more detailed geological information outdoor/indoor pressure differences 18

19 Thankyou for your attention! Iam happy to answer questions. 19