Detailed Geogenic Radon Potential Mapping Using Geospatial Analysis of Multiple Geo-Variables—A Case Study from a High-Risk Area in SE Ireland

Abstract

A detailed investigation of geogenic radon potential (GRP) was carried out near Graiguenamanagh town (County Kilkenny, Ireland) by performing a spatial regression analysis on radon-related variables to evaluate the exposure of people to natural radiation (i.e., radon, thoron and gamma radiation). The study area includes an offshoot of the Caledonian Leinster Granite, which is locally intruded into Ordovician metasediments. To model radon release potential at different points, an ordinary least squared (OLS) regression model was developed in which soil gas radon (SGR) concentrations were considered as the response value. Proxy variables such as radionuclide concentrations obtained from airborne radiometric surveys, soil gas permeability, distance from major faults and a digital terrain model were used as the input predictors. ArcGIS and QGIS software together with XLSTAT statistical software were used to visualise, analyse and validate the data and models. The proposed GRP models were validated through diagnostic tests. Empirical Bayesian kriging (EBK) was used to produce the map of the spatial distribution of predicted GRP values and to estimate the prediction uncertainty. The methodology described here can be extended for larger areas and the models could be utilised to estimate the GRPs of other areas where radon-related proxy values are available.

Application of Airborne Geophysical Survey Data in a Logistic Regression Model to Improve the Predictive Power of Geogenic Radon Maps. A Case Study in Castleisland, County Kerry, Ireland

“…Table 1 Examples of data used for geogenic radon mapping, as indicators of radon source and radon mobility (Ciotoli et al, 2017;Aghdam et al, 2021;Gruber et al, 2013;Aghdam et al, 2022;Elío et al, 2017;Ielsch et al, 2010;Scheib et al, 2009;Omori et al, 2009;Li et al, 2023;Zheng et al, 2023;Rääf et al, 2023;Aghdam, 2021;Aghdam et al, 2019). The Quaternary map of the area (Fig.…”

“…A Geogenic Radon Potential (GRP) map is a promising tool that gives the first evaluation of the amount of radon gas delivered from the geogenic source to ground level (Gruber et al, 2013;Aghdam et al, 2022). The main advantage of a GRP map is that it is independent of anthropogenic factors, and can be produced from existing datasets without site-specific groundbased measurements (Elío et al, 2017).…”

“…Recently, multivariate regression techniques (e.g., ordinary least square regression, logistic regression, and geographically weighted regression) were used by researchers to estimate geogenic radon potential (Ciotoli et al, 2017;Bossew et al, 2020;Aghdam et al, 2022;Elío et al, 2017). Using such methods, accurate predictions of GRP can be made by using a spatial regression in which a target value (either soil-gas radon or indoor radon activity concentrations) is considered as the response variable, and several proxy variables derived from geological, topographic and geochemical data (Table 1) are set as the explanatory input parameters.…”