NATURAL EXPOSURE FROM RADON AND RADON PROGENY IN SPANISH HOUSES

Ziel

The objectives are:
to carry out surveys of radon concentrations in homes in those countries where insufficient data is available;
to develop and test techniques for identifying areas with a potential for high radon concentrations in homes, both on a large scale and for individual building sites;
to improve the understanding of, and develop mathematical models of, the movement of radon from the ground to subfloor spaces and into buildings;
to develop and test countermeasures against radon in homes using laboratory and field studies.
More than 2300 measurements of radon levels in Spanish houses have been completed. The measurements were made using modified Lucas cells and standard conditions. The values found appear to follow a log normal distribution. Approximately 13% of the houses in Spain exceed the recommended value of 148 Bq m{-3}. It was found that houses with high radon levels are situated mainly in the west and northwest of Spain.

A second survey was carried out in order to compare the data derived from integrated and instantaneous measurements. The instantaneous measurements were taken using modified Lucas cells in the early morning during the winter. The integrated measurements were taken using passive etched track detectors from Terradex and the National Radiological Protection Board (NRPB). 94 houses were selected in areas with high radon levels and instantaneous measurements were taken when the passive detectors were installed and when they were removed 3 to 4 months later. No significant differences were found between the results obtained by the 2 techniques.

More than 700 soil samples were collected along the total surface of Spain and were measured by gamma spectrometry. The results are now being processed and will give a map of the radioactive content of Spanish soils. This map with the inclusion of more than 1000 individual measurements of external gamma radiation taken using a portable monitor are part of the data for the atlas of ionising radiation from natural sources in Europe. The relationship between the external dose derived from the radioactivity of soils and the experimental results from the portable monitor measuring in the same place has been examined. The correlation between the geographical distribution of lung cancer in Spain and the presence of radon in houses has been studied.
LNETI (P), University of Cantabria (E), University of Athens (GR) and NSCR Demokritos (GR) will carry out surveys of the exposure of the population to radon in Portugal, Spain and Greece. These will be carried out using passive etched track detectors and active measurement techniques. Additional data will be collected on the radon decay product equilibrium factors and on the origins and characteristics of the radon sources. The average radon concentrations in homes will be calculated, and the variations in concentrations mapped.

BGS (UK) and NRPB (UK) will identify appropriate geological and radiological parameters for radon potential mapping. Existing data will be evaluated, and programmes of collection of relevant data including radionuclide contents of rocks and soils will be started in defined areas. This information will be used to construct maps of radon potential, which will be compared with data on radon concentrations in homes, both from earlier surveys and from new surveys designed to test the validity of the maps.

KVI (NL), CSTC (BE), TNO (NL) Risoe (DK) and SSI (S) have under development mathematical models of radon movement and availability in the soil, movement into buildings through subfloor spaces where present, and subsequent dilution and dispersion. Different models emphasise different parts of this process. These laboratories will meet to exchange information on their models and to draw up a programme of model comparison. The results from the models will also be compared as closely as possible with measurements and will be used to identify the most important parameters for measurement in assessing radon problems in homes.

KVI (NL), the Technical University of Denmark and Risoe (DK) will study soil factors influencing radon availability to buildings using laboratory and field studies. These will include the radon exhalation rate of materials, the influence of porosity, permeability and groundwater on radon movement, and the development of improved instrumentation for characterizing soils on site. The results of this work will be used as input for the mathematical models described above.

WTCB (BE) and TNO (NL) will carry out laboratory and site studies of constructional factors influencing the entry of radon into buildings from the ground. The insight gained will be used in the development and testing of remedial and preventive measures to avoid high levels. This will include the testing of the effectiveness and durability of barrier and diversion techniques for preventing the entry of soil gas.

In the UK, some existing buildings have had remedial measures installed and thousands of new buildings have been constructed using antiradon designs. NRPB will survey the radon levels in a representative sample of these buildings to determine the effectiveness and durability of different countermeasures in practice.

In view of the wide scope of these contracts, it has been found necessary to set up small working groups to coordinate the work on particular topics where there might otherwise be duplication of effort. These groups will exchange information and will meet as required. NRPB will attend the meetings of the groups. The Technical University of Denmark, KVI and the University of Cantabria will collaborate on the subject of soil permeability measurements. KVI, Risoe, CSTC and the Technical University of Denmark will collaborate on models of radon movement in soils and into homes. SSI, CSTC and TNO will collaborate on compartmental models of airborne radon movements within homes, also using data from earlier KVI studies. Within each group the first named laboratory will take the lead in arranging the collaboration, with assistance from NRPB as required.

Apart from cooperation on the specific topics mentioned, all the laboratories will maintain communication with each other and with laboratories in Europe and North America on topics of mutual interest.

Wissenschaftliches Gebiet

Programm/Programme

FP1-RADPROT 6C - Multiannual research and training programme (Euratom) in the field of radiation protection, 1985-1989

Thema/Themen

Data not available

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

CSC - Cost-sharing contracts

Koordinator

UNIVERSIDAD DE CANTABRIA

EU-Beitrag

Keine Daten

Adresse

FACULTAD DE MEDICINA DE SANTANDER CATEDRA DE FISICA MEDICA C/CARDENAL HERRERA ORIA S/N E-
39011 SANTANDER
Spanien

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