On harmonization of radon maps

Abstract

Background: Maps are important tools for geographic visualization of the state of the environment with respect to resources as well as to hazards. One of the hazards is indoor radon (Rn), believed to be the most important cause of lung cancer after smoking. In particular, as part of Rn mitigation policy and in compliance with the European Basic Safety Standards, EU Member States have to declare areas with elevated indoor Rn concentration levels. However, as this is done by national authorities according to individually chosen criteria, the resulting maps are not easily comparable.
 Objective: We aim to identify causes for the lack of compatibility of maps and suggest solutions for the problem.
 Design: This study draws from experiences of recent research projects, literature, and personal involvement of the authors in the discussions.
 Results: An overview is given on causes and effects of lack of compatibility between maps. Existing experiences are reported. Options for defining lack of compatibility and for identifying it are discussed. Methods for harmonization, that is, remediating lack of compatibility, are addressed.
 Conclusions: The difficulty of harmonization increases with the aggregation level of data which support maps. Harmonization is the more difficult, the higher aggregated the data are which support maps. In particular, harmonization of radon priority area maps is technically non-trivial, and theoretical efforts as well as practical tests will have to be undertaken.

Overview of Radon Flux Characteristics, Measurements, Models and Its Potential Use for the Estimation of Radon Priority Areas

“…A definition of RPA was not given precisely in BSS; instead, it was left to member states to provide their own definition of the RPA, which as a consequence led to different RPA maps. Therefore, many efforts have been made to discuss a concept of the RPA [33][34][35][36][37].…”

“…Norway defined all of its territory as RPA. Two other definitions of RPA were also used: an area is defined as RPA (i) if the mean indoor radon concentration of the area is above RL, or (ii) if certain conditions are fulfilled (e.g., the gamma dose rate is above a certain level) [36].…”

“…Since there are different criteria for the definition and identification of RPAs, it is difficult to compare maps created by different national authorities. Bossew et al demonstrated that the identification of RPAs across country borders is affected by the type of data aggregation (e.g., the geometry of the data support) and the scale of the used support [36]. This problem is defined as the Modifiable Areal Unit Problem (MAUP): the higher the support used to aggregate data, the more difficult the harmonisation of the results at the boundaries [36,[55][56][57].…”

Similarities and differences between radon surveys across Europe: results from MetroRADON questionnaire

“…Investigation of comparability is fundamental in the discussion going on about harmonization of indoor radon data at European level (17). Comparability is crucial for joint interpretability of results acquired by different methods.…”

From data to decisions – Quality assurance in radon policy

“…A particular type of data uncertainty is ontological and semantic uncertainty, which occurs if features are defined ambiguously or identified differently by different evaluators (9,10). A related source of uncertainty is scale and resolution dissonance (11), a common problem with the geological and other maps: if a sample point is assigned the geological unit in which it is located, the result may depend on the resolution of the geological map used, since it may be located on a 'small' feature that is not resolved on a coarse map. Similarly, tortuosity of geological borders is increasingly smooth with decreasing resolution, so that a sampling point close to a geological border may, in reality, lie on one side, but is displayed on the opposite side.…”