Radon is a naturally occurring gas that is produced from the radioactive decay of uranium, which is found in rocks and soils. It is the main source of natural radiation to which population is exposed, and therefore we need to determine its distribution in soil and its environmental concentrations. Radon is used to locate, track and quantify greenhouse gas (GHG) emissions using the Radon Tracer Method (RTM) and atmospheric dispersion models. However, there were no tools so far for measuring low radon concentrations in the atmosphere or radon exhalation from soil. Claudia Grossi and Arturo Vargas, researchers from the Institute of Energy Technologies (INTE) of the Universitat Politècnica de Catalunya · BarcelonaTech (UPC), have launched an European project called TraceRadon, which aims to provide new measurement sources, more sensitive reference instruments and effective methodologies for quantifying radon gas concentration in the atmosphere and radon exhalation from soil, which are also key to validating radon flow models across Europe.

TraceRadon is a cross-disciplinary project that brings together scientific communities investigating the atmosphere, climate and environmental radiation under the auspices of the European Association of National Metrology Institutes. The project, which is coordinated by the German National Metrology Institute (Physikalisch-Technische Bundesanstalt (PTB)), aims to develop the first standard methodology for the Radon Tracer Method (RTM) along with a validated high-resolution radon flow map.

The results of tracing radon in the atmosphere and soil with these new techniques will make it possible to enhance measures for protecting people from radiation and to improve GHG inventories, and therefore will lead to greater safety and a better identification of harmful polluting sources.

In particular, the INTE coordinates a working group on improving the instruments for measuring radon concentrations in the atmosphere and soil. This technology will be used to harmonise instruments and validate radon flux models by comparing them with other models and using intensive field campaigns. The new radon gas detectors that will be built as part of the project will be tested with field measurements in Germany, Italy, France and England.

Claudia Grossi, the researcher who designed and promoted the project, highlights that “this initiative will allow us to develop for the first time a complete metrology for high quality measurements of atmospheric radon activity concentrations and radon fluxes and therefore to better identify areas with high soil radon concentrations”. The project will also “help to improve greenhouse gas emission maps and, in short, to define the best strategies for reducing these gases and tackling climate change”, claims the researcher.

The tools and instruments developed within the framework of the project will be made available to atmospheric control networks, such as the Integrated Carbon Observation System (ICOS), and to environmental radiation monitoring networks, such as the European Radioactivity Data Exchange Platform (EURDEP).

The project is part of the EMPIR programme, co-financed by the European Union’s Horizon 2020 programme, with a budget of 2.4 million euros. It is expected to continue until 2023. In addition to the UPC, the project involves the University of Cantabria and 16 other institutions and research centres from European universities in Germany, Poland, Hungary, Sweden, Austria, the Czech Republic, France, the United Kingdom, Serbia, Romania and Italy.