Occurrence of 222Rn and 226,228Ra in underground water and 222Rn in soil and their mutual correlations for underground water supplies in southern Greater Poland

Abstract

European Union Council Directive 2013/51/EURATOM recently sets out so-called indicator parameters for: radon, tritium and indicative dose of water intended for human consumption. The aim of this research was to elaborate an effective procedure for determination of radon and radium 226,228Ra isotopes (which are potentially the main contributors to the internal dose from drinking and cooking water) and to find the possible relationships between these radionuclides in underground water reservoirs and 222Rn concentration in the soil gas in their vicinity. The research was performed by applying a non-volatile and water-immiscible scintillation cocktail based on a pure diisopropylnaphthalene (Ultima Gold F: UGF), which allow for efficient radon extraction from 0.5 dm3 of water samples to 20 cm3 of scintillation phase and its direct determination with a detection limit of 5 × 10–3 Bq dm−3. The further preliminary concentration of 3 dm3 of crude water samples by evaporation to 0.5 dm3 samples led to the removal of all unsupported 222Rn activity and allowed the 226Ra determination via equivalent 222Rn detection after one-month samples storage using a low-background Triathler liquid scintillation counter in the α/β separation counting mode. Together with determination of 226Ra isotope in water samples, the simultaneous measurements of 228Ra and 222Rn radionuclides concentrations in water as well as 222Rn activity in the soil gas around the water supply sites were performed. The achieved limit of 226Ra detection was at a very low level of 10–3 Bq dm−3. The measured values of 226Ra concentration in 50 public underground water supply units for the Kalisz district of Poland were relatively low and ranged from below detection limit to 28.5 × 10–3 Bq dm−3 with arithmetic mean and median values of 12.9 and 12.2 × 10–3 Bq dm−3, respectively. Weak correlations were observed between activity concentrations of 226Ra and 222Rn in the crude water samples (R2 = 0.31) and 222Rn in water and its concentration in the nearby soil gas (R2 = 0.48).

An Evaluation of Radon in Drinking Water Supplies in Major Cities of the Province of Chimborazo, Central Andes of Ecuador

“…Detectable values of 226 Ra were only observed in six springs in the cantons of Guano and Chambo, within the range 0.47-0.67 Bq/L. Some scientific publications report weak correlations between the 226 Ra and 222 Rn concentrations [87,100], while other papers, in contrast, a significant correlation between these radionuclides [11,101,102]. In the current study, a significant correlation (R 2 = 0.953) between the concentrations of 226 Ra and 222 Rn was observed, which can be explained by the fact that the lithologies present in the aquifer are strongly tectonized, brittle, or weathered, facilitating their dissolution and therefore the incorporation of 226 Ra in water.…”

“…where E ing is the annual effective dose from ingestion in Sv, DCF is the conversion factor of the ingested dose of 222 Rn (10 −8 Sv/Bq [83]), C Rn is the radon concentration in drinking water in Bq/L, and V a is the annual volume of water consumed. To calculate the dose, a consumption of two liters per day was assumed, multiplied by the 365 days of the year; it is found that the water consumption for a standard adult drinking the same water directly from the tap is 730 L [84][85][86][87].…”

Assessment of Heavy Metals and Radionuclides Concentration in Selected Mineral Waters Available on the Polish Market

“…Trace amounts of radium 226 Ra were detected in the investigated waters. The differences in the amount of radium 226 Ra in the waters are due to the soil structure and its composition [60][61][62]. The nature of the tested water is also an important aspect.…”

Measurement of Radon-222 Concentrations in Selected Soil Samples in Al-Mothafeen Area (Kerbala, Iraq) by Using the CN-85 Detector

“…All three series contain alpha emitters. Many researchers have studied the emission of radionuclides (alpha emitters) in soil samples by using the plastic nuclear track detector in some Iraqi areas (El-Araby et al 2021, Bem et al 2021, Abojassim et al 2017, Abojassim 2018, Al-Gharabi and Al-Hamzawi 2020). The aim of this study was to measure the annual effective dose due to radon and radioactivity for radium and uranium of soil samples in Al-Mothafeen sites.…”