Assessment and Mapping of Radon-prone Areas on a regional scale as application of a Hierarchical Adaptive and Multi-scale Approach for the Environmental Planning. Case Study of Campania Region, Southern Italy.

Nowadays, it is well established, among the international scientific community, that insided wellings the largest contribution to the indoor Radon levels is provided by the source of the exhalated Radon, produced both directly from the soil located underneath the buildings and from the neighbour soils. This shared awareness has induced many European public institutions, responsible in matter of public health, to issue directives aimed at the assessment of the potential Radon exhalation from the soils, at regional scale, in order to achieve a planning of the radiogenic risk both in the residential buildings and in the working places. However, on one side, the lack of consolidated methodologies and procedures, shared among the experts’ community, has produced a valuable intense investigation research activity; on the other one, it led to the developing of different procedures, starting from diversified approaches. Synthetically, they can be classified according to the following typologies: i) indoor Radon measurements campaign-based approaches, ii) geology-based and geology-indoor correlation based, and iii) integrated ones. On the base of this last approach, the authors have started an interdisciplinary research program with contributions from Geology, Geomorphology, Soil Science, Environmental Physics, Building Engineering and Radiology and Epidemiology aimed to the development of a standard methodology, based on a multi-scale hierarchical (regional - provincial - sector- zone site) procedure of assessment of the Radon exhalation from soils. Such a procedure exploits an integrated, adaptive, approach to the problem as it requires the use of techniques of analysis, which are differentiated at the different scales of the territorial surveys and analysis. At the same time, they are interactive and progressively more deepened and more specific, from the regional to the zone mapping and modelling at the scale of a single site. The research is supported by a built-in database about Campania Region, consisting of both suitable territorial informations and experimental data provided by Radon activity concentration measurements in soil-gas performed in several sites and indoor measurements, integrated in a GIS-based management procedure. For its properties, this interdisciplinary multiscalar hierarchical adaptive approach can be successfully applied in many environmental studies and analysis. An interdisciplinary hierarchical multiscalar and adaptive methodology like the one described in this paper turns out to be a very powerful tool in many environmental and territorial planning approaches, especially wherever a “vast area” approach is needed to the environmental issues, i.e., the case of the urban acoustical or the electromagnetic pollution zoning. The “vast area” is an emerging concept and it regards a systemic approach to urban and regional planning methodology of analysis, design and management. Integration is pursued between the contributions given by the various disciplines involved in the planning process