It is possible to order long-term measuring with detectors (measuring period at least 2 months) or a short-term measuring with radon monitor (measuring period up to 7 days). Read more under "Methods for measuring radon". The Environmental Board does not provide the service for measuring the radon level of the soil. In case of questions related to the services offered, please contact the Chief Specialist of Radiation Monitoring of the Radiation Monitoring Bureau of the Climate and Radiation Department:
Alar Polt
Chief Specialist of Radiation Monitoring of the Radiation Monitoring Bureau of the Climate and Radiation Department
It is recommended to measure radon levels during the heating period, as the leaking of radon into the house has favourable conditions and the result is expected to reflect the worst situation. It is reasonable to measure the level of radon on the ground floor of a building (in some cases also on the second floor) or in the basement, if the rooms there are used as living or working spaces. Radon generally does not reach higher floors and does not usually cause problems there. You do not need to change your usual way of life during the measurement - people should live their daily lives and use the premises as usual.
The concentration of radon in the building varies over time, since both the separation of radon from the ground and exit from the premises are associated with changes in weather conditions.
In addition, radon levels in the building are influenced by people's way of life, such as how often windows and doors are opened. Therefore, whenever possible, a long-term measuring method of at least 2 months should always be used. The result of the long-term measuring makes it possible to compare it with the reference level given as the average of the year, from which options for reducing the radon concentration in air must be considered.
The results of the short-term measuring method are reliable for the measurement period, but it is not reliable to compare this result with the annual indicative value of a radon level. This measuring method should be chosen if you need measuring urgently (ongoing repairs, fast purchase or sale of real estate, etc.) and, if possible, carry out measuring of radon level also using a long-term method.
This is a method that complies with the Standard EVS-ISO 11665-4. The method is used to assess the annual average value of the radon concentration. Long-term radon measuring of the Climate and Radiation Department of the Environmental Board has been accredited by the Estonian Accreditation Centre (certificate L175).
Two detectors (see photo) are installed on the object being measured for at least two months. The use of two detectors is usually enough to measure the level of radon in an apartment, in a private house and in other buildings with an area of up to 200 m². In case of larger buildings (schools, industrial buildings, office buildings, etc.), a larger number of detectors may be needed for measuring. It is recommended to find out the exact number of detectors required in cooperation with a specialist of the Climate and Radiation Department. The number of detectors must also be indicated on the order format and the cost of the measuring must be changed accordingly. The total cost is the number of detectors multiplied by EUR 25.50.
The CR-39 plastic detector is located in a cup with a non-airtight cap (d=2.5 cm; h=5.5 cm). Alpha radiation from the decomposition of radon creates traces of alpha particles on a piece of plastic. After the end of the measuring period, the detectors are chemically treated to highlight traces and analyse them by using a microscope and a special computer program. As an output parameter, the average radon concentration of air during the measuring period is found. The detectors used to measure the radon concentration indoors are packed in an airtight aluminium bag and sent to the customer by post (unless otherwise agreed) with a written instructions for the installation of the detectors. Detectors are very easy to install and these do not interfere with everyday life.
After the end of the measuring period, the customer sends the detectors back to the Climate and Radiation Department by post or delivers these himself or herself there. After analysis, a measurement report is issued on the results obtained.
This is a continuous measurement method in which the radon monitor AlphaGuard (dimensions 33x23x12 cm, see the photo) is installed in the building for up to 7 days, which monitors changes in radon concentration over time. The equipment registers the average results of ten minutes or one hour, and later it is possible to obtain a graph of the change in radon concentration in the indoor air of the building during the measuring period with a computer program on the basis of measurement data.
It is recommended to use the method primarily to check the efficiency of a ventilation system in a certain mode of operation. The method is not suitable for assessing the annual average of radon level, as radon levels may vary considerably depending on the weather in the short term. However, the results obtained provide indication of the presence or lack of a radon problem in the indoor air of the building.
The radon monitor is installed in the building by the customer himself/ herself in accordance with the instructions given by the specialist of the Climate and Radiation Department, and after the end of the measuring period, the equipment is brought back to the Climate and Radiation Department (unless otherwise agreed). The equipment is in a suitcase during transportation (dimensions 40x20x50 cm).
A report is issued on the average measuring results of the measuring period and the graph characterising the fluctuation of radon concentration. The measuring quality is ensured by regular calibration of the equipment and by participation in international reference measurements.
Last updated: 02.12.2022
