National Radon Action Plan and Radon Database Experience in Switzerland
A brief History 80s: first investigations about the dangers of radon in residential areas 1992:Radonprogramm Schweiz(RAPROS): measurements, geology, construction material, remediations etc. 1994:ordinance on radioprotection, limiting values: 1000 Bq/m 3 dwellings, 3000 Bq/m 3 working places 2004:new findings from epidemiological studies (Darby et al. 2004) 2009:WHO s radon handbook; recommendation: reference value 100 300 Bq/m 3 in dwellings 2012: National Radon Action Plan 2012-2020 2014: revised SIA-Norm 180 2018: new ordinance on radioprotection 2
Radon in Switzerland ~150000 buildings last bin contains all with >1000 Bq/m 3 Legal regulations since 1994 3
Average exposition to ionizing radiation Total average for people in Switzerland: ca. 5.5 msv/year 4
Radon prevention: involved parties Suva for workplaces dwellings schools 5
National Radon Action Plan 7 measures: 1. Revision of the legal regulations 2. Extending our knowledge of radon exposure in dwellings 3. Promotion of protective measures against radon in buildings 4. Planning an efficient strategy for remediation 5. Including radon in the training of construction experts 6. Improving public awareness to health problems caused by radon 7. Developing the tools and methods Passed by the federal council may 25, 2011 6
1. Revision of the legal regulations Designated new legal values ORaP of 1994 dwellings limiting value 1000 Bq/m 3 (annual average) Draft revised ORaP reference value 300 Bq/m 3 (annual average) new workplaces reference value 400 Bq/m 3 (annual average) reference value 300 Bq/m 3 (annual value) existing workplaces radon prone workplaces limiting value 3000 Bq/m 3 (average over the monthly working time) entry point 1000 Bq/m 3 integrated radon concentration > 170 kbqh/m 3 planed exposition 7
2. Extending our knowledge of radon exposure in dwellings Future measuring campaigns should not mainly be targeted to high risk areas. In view of the new recommendations, the denser populated regions in Switzerland turn into areas of medium to high radon risk. Special emphasis will be given to new buildings and public buildings, particularly to schools, kindergartens, hospitals etc. 8
3. The promotion of protective measures against radon in buildings shift from stripe foundations to continuous ground slabs better isolation of the building shells to save energy? 9
4. Planning an efficient strategy for remediations Remediation method Ventilation Tightness Drainage/ Radon well Hollow space Number of cases 67 50 21 9 Average reduction all cases 38% 26% 48% 49% Average reduction Initial radon concentration 24% 31% 44% 52% <1000 Bq/m 3 Average reduction Initial radon concentration 48% 22% 56% 48% >1000 Bq/m 3 Drainage/Radon well, hollow space: effective, but generally expensive Ventilation is more effective than better Tightness A challenge arises from energy-conserving remediations, while new low energy houses are generally radon safe. 10
5. Including radon in the training of construction experts Many architects and construction experts are not aware of the radon problem The FOPH has appointed three radon delegates based at three universities of applied sciences, who work on including the radon issue in the basic education of building experts Improve the knowledge of radon at the level of apprenticeship and professional training 11
6. Improving public awareness to health problems caused by radon Most people in Switzerland do not know about radon: 60% have never heard about the radon problem (30% in high risk areas, Gruson et al. 2010) Brochures in collaboration with the Alpine countries distributed together with building permits: Precautions for new buildings Mitigation measures in existing buildings The effect of retrofitting thermal insulation Radon measurement and evaluation available at www.ch-radon.ch 12
7. Developing the tools and methods Develop a protocol for short term measurements (particularly for real estate transactions) A more detailed statistical evaluation of the available data (measurements, remediations) A better understanding of Thoron (from construction material) and the equilibrium factor An improved knowledge of geological factors and the influence of building characteristics a predictive mapping of the radon risk ( Wednesday) 13
Radon Database 2005 2006 2007 2008 concept migration of data put into service maintenance and development programming established by law
External users of the database Federal office: all data Measuring service: own data Cantons: all data of their territory 15
Collected data name of resident and address of the building supplementary addresses characteristics of the building information about the measurements and their results information about a possible remediation 16
Screen example database in three languages 17
Letter with interpretation of the results can be produced automatically for each building 18
Search tool on our website Federal Department of Home Affairs FDHA 19
Problem: data quality cantons measuring services federal office 20
Thank you for your attention! I am happy to answer questions. 21