Radon distribution in groundwater of Taiwan

Abstract

Radon levels were surveyed in 517 monitoring wells constructed in five major groundwater areas of Taiwan. The radon concentration in groundwater samples varied in a wide range from below the detection limit of 18 pCi/L up to 1,100 pCi/L. A worldwide comparison of reported groundwater radon levels was conducted. Overall radon levels in Taiwan groundwater are relatively low compared to other countries because the geology of Taiwan is mainly comprised of sedimentary rocks. Among the 517 wells monitored, only five wells were found with radon concentrations higher than 500 pCi/L. These five wells are all located near the Chaochou Fault in the Pingtung Plain. This study suggests that well sites near the Chaochou Fault could be good locations to monitor radon anomalies for earthquake prediction and should be avoided for developing domestic water supply. In the recharge area near the Chaochou Fault, the radon concentration in groundwater from shallow wells was approximately 1/2 to 1/4 of that from deep wells in the same cluster.Resumen Se investigaron los niveles de radón en 517 pozos de monitoreo, construidos en las cinco mayores µreas de agua subterrµnea de Taiwan. La concentración de radón en las muestras de agua subterrµnea varía en un rango amplio, desde inferior al límite de detección que es 18 pCi/L hasta 1,100 pCi/L. Se realizó una comparación a escala mundial de los niveles de radón reportados en agua subterrµnea. En general los niveles de radón presente en el agua subterrµnea de Taiwan, son relativamente bajos comparados con otros países, puesto que la geología de Taiwan estµ compuesta de rocas sedimentarias. Entre los 517 pozos monitoreados, solamente en cinco se encontraron concentraciones de radón mayores a 500 pCi/L. Estos cinco pozos estµn todos localizados cerca de la falla ChaoChou en la Planicie de PingTung. El presente estudio sugiere que los pozos cercanos a la falla Chaochou, podrían ser buenos sitios para monitorear anomalías de radón para la predicción de terremotos y deberían evitarse para los desarrollos de abastecimiento de agua potable. En la zona de recarga cerca de la falla Chaochou, la concentración de radón en agua subterrµnea obtenida en pozos someros, fue aproximadamente de a de aquella en pozos profundos ubicados en el mismo sector.

Establishing the range of background for radon variations in groundwater along the Serghaya fault in southwestern Syria

“…Many researchers (e.g. Pane et al, 1995;Han et al, 2006;Surbeck, 2007) discussed the hydrogeological control of radon variations in karstic aquifers and the spatial correlation with changing groundwater levels of the monitoring site due to decreasing or increasing precipitations. In view of their results, it has been found that occasional radon changes in groundwater usually appear in a restricted time of the year announcing the arrival of the new percolating rainwater after the rainfall season.…”

“…Radon isotope ( 222 Rn), for simplicity called "Radon" in the following, is a daughter nuclide of radium ( 226 Ra), which in turn is produced from the decay series of uranium ( 238 U). As a naturally occurring radioactive gas, radon is widely utilized in various fields of earth sciences, such as hydrogeological studies Pane et al, 1995;Han et al, 2006;Surbeck, 2007); detecting buried active faults (Baubron et al, 2002;Al-Hilal and Al-Ali, 2010) and monitoring seismic activities (Teng, 1980;Kuo et al, 2006;Erees et al, 2007). Furthermore, radon method is commonly used in most uranium exploration programmes due to its efficiency, low cost and simplicity (Dyck, 1975;Gingrich, 1984;Jubeli et al, 2000).…”

Application of Machine Learning Algorithms for Geogenic Radon Potential Mapping in Danyang-Gun, South Korea

“…Furthermore, radon levels were high in areas where the fault density varied between 0.58 and 1.2 (FR 2.32). Notably, fault systems located in fracture zones provide a route for radon to migrate upward from deeper sources (Han et al, 2006). Finally, in terms of lithology, the FR analysis yielded higher values, of 200.65, 32.74, and 13.71, for Cretaceous acidic dike (Kad), Cretaceous quartz porphyry (Kqp), and Cambrian quartzite and slate (CEdy) units, respectively.…”

Περιβαλλοντική Υδρογεωλογική Μελέτη Της Λεκάνης Του Λούρου Ποταμού

“…Αλ θαη νη πςειέο ζπγθεληξψζεηο ξαδνλίνπ ζην πφζηκν λεξφ κπνξεί λα πξνθαιέζνπλ θίλδπλν γηα ηελ αλζξψπηλε πγεία (Xinwei, 2006) εληνχηνηο ην ζπληζηψκελν φξην πνζηκφηεηαο δελ έρεη αθφκε θαζνξηζηεί, ελψ ζχκθσλα κε νδεγία ηεο USEPA (1999), ε πξνηεηλφκελε ζπγθέληξσζε θζάλεη ηα 150 kBq m -3 . Δικόνα 8.52: α. Ζ αιπζίδα ησλ θπζηθψλ ξαδηελεξγψλ ζηνηρείσλ ηεο ζεηξάο ηνπ 238 U (Surbeck, 2007), β. Ζ ζπγθέληξσζε ηνπ ξαδνλίνπ ζην λεξφ δηάθνξσλ ρσξψλ (ηξνπνπνηεκέλν απφ Han et al, 2006).…”