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Radon in Urban Areas

Radon in Urban Areas. Jens Wiegand Würzburg University. 19 May 2005. Jens Wiegand. Radon. natürlich vorkommendes Edelgas, radioaktiv, mit Hwz.: 3,8 Tage. 4,5 10 9 a. Th-234. U-238. Pa-234. 24,1 d. 1,18 min. Pb-214. Po-218. Rn-222. Ra-226. Th-230. U-234. 3,1 min. Bi-214.

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Radon in Urban Areas

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  1. Radon in Urban Areas Jens Wiegand Würzburg University 19 May 2005 Jens Wiegand

  2. Radon natürlich vorkommendes Edelgas, radioaktiv, mit Hwz.: 3,8 Tage 4,5109 a Th-234 U-238 Pa-234 24,1 d 1,18 min Pb-214 Po-218 Rn-222 Ra-226 Th-230 U-234 3,1 min Bi-214 27 min 3,83 d 1,6103 a 75103 a 245103 a Pb-210 Po-214 20 min - Strahler Mutter- Nuklid Bi-210 22,3 a 16410-6 s - Strahler Stabiles Isotop Pb-206 Po-210 5,0 d 138 d 19 May 2005 Jens Wiegand

  3. Why to work as a scientist about radon? ? Radon is dangerous…….see later To use radon as a tool to identify geogenic processes ? Radon ? ? ? 19 May 2005 Jens Wiegand

  4. Wolfango Plastino et al.: Very precise monitoring since 1996 (Rn, pH, EC, TDGP, T) Jens Wiegand et al.: ½ h monitoring since 2003 (Rn, T), and from now on additionally: CO2, EC, TDGP) W. Plastino, R. Di Giovambattista, P. G. Catalano, F. Bella, Chemical-physical groundwater anomalies related to seismic events in central Apennines (Italy), Earth and Planetary Science Letters, submitted.

  5. Thoron 19 May 2005 Jens Wiegand

  6. Radon is the second most cause of lung cancer (smoking is the first)

  7. Folgen der Strahlenexposition 7 % of German lung cancer are due to radon(2500 - 3000 cases / year) Lung cancer risk increases with 10 % per 100 Bq/m³ EPA assumes that approx. 20 000 people die due to radon every year 19 May 2005 Jens Wiegand

  8. Regulation in Germany Working place: action level 2 MBq x h/m³ (6 mSv/a, 1000 Bq/m³) limit value 6 MBq x h/m³ (20 mSv/a, 3000 Bq/m³) At home: Rn-Protection-Law under preparation aim value 100 Bq/m³ 19 May 2005 Jens Wiegand

  9. Why to work as a geoscientist about radon? Radonexposition in dwellings Radon comes to 95 % from the geological bedrock Building material and drinking water only 5 % 19 May 2005 Jens Wiegand

  10. good knowledge about the geogenic soil radon potential • many measurements under undisturbed soil conditions • but: • only every 3 km 1 measuring point • what parameter • additionally to geology? Würzburg 19 May 2005 Jens Wiegand

  11. Is it possible to transfer the results into the cities? ? Measurements only in rural areas Measurements in urban areas under consideration of anthropogenic parameters still missing 19 May 2005 Jens Wiegand

  12. The 10 Point System Identification and evaluation of processes controlling the soil radon potential 19 May 2005 Jens Wiegand

  13. Radon migration in the soil Radon Exhalation (transfer from soil to atmosphere) Diffusion (by concentration gradient) Convection (by pressure differences) Radium Radon Radium Radon Radon Emanation (entry into pores)

  14. Radon emanation controlled by: • Radium concentration • Radium distribution in the mineral grains

  15. Radon emanation processes (Wiegand 2001)

  16. The 10 point system Identification and evaluation of processes controlling the soil radon potential - 7 parameters identified - Semi-quantitative evaluation - Ranked according to importance - Score between “0 and 10” 19 May 2005 Jens Wiegand

  17. Definition of soil radon potential A qualitative and semi quantitative evaluation of: - Radon concentration in soil-gas - Radon availability (possibility to migrate), i.e. permeability 19 May 2005 Jens Wiegand

  18. 7 Parameter of soil radon potential 1. Occurrence of backfill 2. Geology 3. Relief (variety of soils) 4. Vegetation 5. Tectonics (faults) 6. Soil sealing 7. Traffic vibrations 19 May 2005 Jens Wiegand

  19. Occurrence of made ground * value from NCRP (1988) (Wiegand 2001) 19 May 2005 Jens Wiegand

  20. Geology (Wiegand 1996)

  21. Geology (Wiegand & Büchel 1997)

  22. Relief (variety of soils)

  23. Relief (variety of soils)

  24. Relief (variety of soils) Relief (= Einfluss der Böden)

  25. Relief (variety of soils) (Wiegand 2001)

  26. Relief (variety of soils)

  27. Relief (variety of soils) (Wiegand 2001)

  28. Vegetation

  29. Vegetation (Wiegand & Feige 1999)

  30. Tectonics (natural faults) (Wiegand & Büchel 1997)

  31. Tectonics (man made faults) (Wiegand 2001)

  32. Soil sealing (Wiegand 2000)

  33. Soil sealing (Wiegand 2003)

  34. Traffic Vibrations

  35. Traffic Vibrations (Wiegand 2003)

  36. Traffic Vibrations (The model)

  37. Traffic Vibrations (The model)

  38. The 10 point system Score: 7 House: granite, plain, fields, railway track (Wiegand 2001) 19 May 2005 Jens Wiegand

  39. The 10 point system (Wiegand in press)

  40. 0.5 m depth, n=511 (without tectonics, soil sealing) 1000 2 R =0,94 n=3 n=46 100 n=50 10 - 90% n=128 25 - 75% n=163 Mean ²²²Rn conc. of soil-gas [Bq/l] n=88 Median n=10 n=20 10 n=3 1 0,1 0 1 2 3 4 5 6 7 8 Soil radon potential The 10 point system (Wiegand in press)

  41. Application of the 10-ps • Estimation of soil radon potential • Estimation of radon conc. in soil-gas • Estimation of indoor radon (if the radon source is the soil and not the building material) • Verification of the local radon risk in radon prone areas • Support of measurements (indoor radon or soil-gas) 19 May 2005 Jens Wiegand

  42. Advantage of the 10 PS • Applicable at any site on a local scale • Application is independent of season • Evaluation of parameters were done under standardised conditions • (No need of further measurements) 19 May 2005 Jens Wiegand

  43. Thank you for your attention ! Verena Husmann Sebastian Feige Simone Schmid Simone Tulke Bernd Schott Amir Yousseff Helga Westerhuis Dieter Bleile 19 May 2005 Jens Wiegand

  44. Vegetation Vegetation LAK: Light-Application- chamber (n): Volume (Feige & Wiegand in prep.)

  45. 000929-1 - birch tree 2000,00 1500,00 Radon [Bq/m³] 1000,00 Radon-222 [calculated] Radon-222 500,00 0,00 0,00 200,00 400,00 600,00 800,00 1000,00 1200,00 1400,00 1600,00 Duration of measurement [min] Vegetation Vegetation (Feige & Wiegand in prep.)

  46. Vegetation (Kemski et al. 1996)

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