How do we measure the radon concentrations in buildings

Radon Dosemeters

Most radon and radon daughters measurement methods are based on the detection of alpha particles emitted during the radioactive decay. The measurement methods are generally divided into active or passive, short or long term. Usually passive techniques are simple, with little cost, while the active techniques are short and require electricity consumption. The measurements results show the average radon concentration in the air inside a building. Radon concentration is measured in Bq / m3.

The final assessment is also taking into account changes in the concentration of radon and radon daughters; these changes depend on seasonal factors, weather conditions, the characteristics of the building, the use of heating and cooling, the inhabitants habits and other factors. Usually the concentrations are higher in the evening and at night compared to the morning and afternoon hours. The concentrations are also higher in the winter than in summer.

EEAE recommends using passive detectors and conducting long-term measurements, at least three months and preferably in autumn and winter, in order to reduce the influence of these factors.

EEAE performs radon concentration measurements, using a series of techniques and detectors. For routine measurements of radon concentration in residences and workplaces the dosemeters used are based on the technique of trace detectors. The method is based on placing a probe trace SSNTD (Solid State Nuclear Track Detector) into a plastic cover of 7 cm diameter.

The dosemeter is placed somewhere in the house for a period ranging from three months to a year. Then, the dosemeter is returned to EEAE for laboratory processing and measurement. Written results are reported to the persons concerned. The method used by EEAE is accredited by ESYD in accordance with ISO 11665.


National overview radon concentrations

With the cooperation of local authorities across the country and under the "Prisma" project (National Action KRIPIS, NSRF 2007-2013 financed by the European Regional Development Fund) EEAE implements a long-term plan aiming at the mapping of the radon concentrations in houses all over Greece. The coordinated effort of recording the radon concentrations in indoor air in residences throughout the country (national radon survey) began in 2010 and continues intensively. Radon concentrations are measured in residences at random, throughout Greece and are registered on EEAE database in order to estimate the annual population exposure. Participation in the program is voluntary and is implemented by the help of the municipalities, which have the responsibility for the proper distribution and collection of the detectors as instructed by EEAE.