The challenge of making correct radon measurements
Testing laboratories aim to accomplish high standards in terms of laboratory practice, accuracy of their results and participation in inter-comparison exercises. To achieve that they formerly followed their own internal procedures and designed their own measurement protocols. Given that scenario, how reliable are test results? How can we compare the results obtained by two different laboratories using different testing protocols? The question becomes more relevant when we need to fulfil national legislation and provide results that would be accepted as legal evidence in a court of law.
The best way to provide reliable test values and comparable results among laboratories might be to measure the same sample parameters following the same methods. Unfortunately, this is not always possible. One can perform a test and provide results for the same sample parameter using different approaches. ISO means International Standards Organization. The list of existing standards is very large, and they are applicable to almost any possible measurement. Not only testing, but also calibration has to be made according to common practices. Therefore, the only possible solution is to comply with ISO/IEC 17025 (revised in 2017).
The name of the game – Accreditation according to ISO/IEC 17025
ISO/IEC 17025 contains general requirements to assess the proper competence of testing and calibrating laboratories. It is a full quality system that can be applied to any testing/calibration activity and is particularly relevant to the measurement of radon levels. Accreditation means that the laboratory has met the Management Requirements and Technical Requirements of ISO/IEC 17025 and is deemed technically competent to produce calibration and testing results. This means that we can always verify that our measurements are correct, both accurate and reproducible. This standard is valid for any organization performing testing activities and applies equally to very small laboratories right up to large corporations.
Due to the recent EURATOM BSS Directive, it is necessary to establish a reference level of radon gas concentration in each EU member state. The Directive mandates member states to monitor radon levels in dwellings, work places and public areas. A detailed list of actions is included in the Directive and all member states must set up a national radon action plan. Hence the need to have credible results is essential and the consequences of bad practice may imply serious deviations from the level of accomplishment required by the Directive. Currently, most national authorities demand measurement protocols from the testing service being used and a quality system in place. The accreditation awarded under ISO/IEC 17025 meets this demand ensuring confidence in the accuracy and precision of measurements. It comes with an implicit guarantee that a quality system is in place with systematic procedures supporting each reported value.