Task 4.4: Harmonisation of radon priority areas across borders

The aim of this task is to develop a strategy to harmonise defined RPAs across borders and to incorporate it in a guideline.
Since RPAs are defined based on different Rn policies (related to different ways to interpret and to implement the EU-BSS) and the availability of data for the predictor quantities, RPAs defined by individual countries will in general not be consistent across borders. In this task, existing approaches to defining RPAs will be compared and tested using different datasets, possible causes of the inconsistencies identified, the obstacles that currently exist with regard to harmonisation of RPA maps identified and ways of “top-down” harmonisation of RPAs proposed. As an alternative approach, the concept of RHI will be proposed in Task 4.3 which may “bypass” the lack of consistency in defining RPAs by creating a universally applicable index of geogenic Rn which does not compete with existing RPA concepts, but complements them. This is a particularly sensitive issue because harmonised approaches must not interfere with and jeopardise national approaches, and hence, appropriate communication and involvement of stakeholders is indispensable.