Development of a Geogenic Radon Hazard Index—Concept, History, Experiences

Abstract

Exposure to indoor radon at home and in workplaces constitutes a serious public health risk and is the second most prevalent cause of lung cancer after tobacco smoking. Indoor radon concentration is to a large extent controlled by so-called geogenic radon, which is radon generated in the ground. While indoor radon has been mapped in many parts of Europe, this is not the case for its geogenic control, which has been surveyed exhaustively in only a few countries or regions. Since geogenic radon is an important predictor of indoor radon, knowing the local potential of geogenic radon can assist radon mitigation policy in allocating resources and tuning regulations to focus on where it needs to be prioritized. The contribution of geogenic to indoor radon can be quantified in different ways: the geogenic radon potential (GRP) and the geogenic radon hazard index (GRHI). Both are constructed from geogenic quantities, with their differences tending to be, but not always, their type of geographical support and optimality as indoor radon predictors. An important feature of the GRHI is consistency across borders between regions with different data availability and Rn survey policies, which has so far impeded the creation of a European map of geogenic radon. The GRHI can be understood as a generalization or extension of the GRP. In this paper, the concepts of GRP and GRHI are discussed and a review of previous GRHI approaches is presented, including methods of GRHI estimation and some preliminary results. A methodology to create GRHI maps that cover most of Europe appears at hand and appropriate; however, further fine tuning and validation remains on the agenda.

Improving Regulation and the Role of Natural Risk Knowledge to Promote Sustainable Low Enthalpy Geothermal Energy Utilization

“…The Latium regulation is the only one that considers the LEG radon hazard for human health, forbidding (in the earlier, now repealed, version) vertical LEG where radon concentration is higher than 300 Bq/m 3 . The radon hazard is a relevant issue in Latium, where geogenic sources of radon are active, but the drilling LEG contribution to this hazard should be very low and can be easily nullified by adopting rigorous borehole sealing treatments [21,22]. The definition of a (low, respectful of local natural conditions) threshold without exception for sealing solutions, seems to be contradicting the purpose to promote LEG sustainable widespread diffusion.…”

A Study of Natural Radioactivity Levels and Radon/Thoron Release Potential of Bedrock and Soil in Southeastern Ireland

“…By mapping the Geogenic Radon Potential (GRP) it is possible to identify radon-prone areas (RPA) [ 8 ], i.e., areas where indoor radon concentration is likely to be higher than the national average [ 9 ]. A GRP map is typically prepared exclusively based on geological information (e.g., radiometric and geochemical data, lithological types, U and Ra content, soil-gas radon, and soil permeability) [ 3 , 10 , 11 , 12 ]. Among the data mentioned, airborne gamma-ray spectrometer surveys can be efficiently utilized to provide high-resolution geogenic radon and thoron maps expressed in terms of equivalent concentrations of their parent nuclides; uranium-238 (eU, estimated from 214 Bi) and thorium-232 (eTh, estimated from 208 Tl), respectively [ 13 ].…”

A New Methodology for Defining Radon Priority Areas in Spain

“…The problem was that different interpretations of RPA were introduced in each country [11][12][13][14][15][16][17]. In Europe, both mapping methodologies and the definitions of RPAs are diverse [18][19][20][21][22][23][24][25][26].…”