Groundwater Radon Research Articles

Dose assessment from exposure to uranium and radon in groundwater in Safi province, Morocco

ABSTRACT In this study we evaluate the uranium and radon concentrations in groundwater from the Province of Safi. The samples were collected from 58 wells across five communes and analyzed using the LR-115 type II detector. Results indicate that uranium concentrations ranged from the Limit of Detection (LLD) to 3.73 µg/l, with a mean of 0.72 µg/l, well below the World Health Organization’s safe limit of 30 µg/l. Radon levels varied from LLD to 2.39 Bq/l, with an average of 0.60 Bq/l, also below the United States Environmental Protection Agency’s limit of 11 Bq/l. The estimated total annual effective dose due to uranium and radon ranged from 3.47 to 18.84 µSv/y, with an average of 7.54 µSv/y, which is significantly lower than the European Commission’s recommended limit of 100 µSv/y. This investigation represents the first study of uranium and radon levels in groundwater in the Province of Safi, providing valuable data for future research and public health.

Radiological assessment of radon in groundwater of the northernmost Kashmir Basin, northwestern Himalaya.

This study investigates the radon concentration in groundwater in Kupwara, the northernmost district of the Kashmir valley. It further assesses the annual effective dose experienced by the district's diverse population-infants, children, and adults-attributable to both inhalation of airborne radon released from drinking water and direct ingestion. In addition to this, the calculation of gamma dose rate is also carried out at each of the sampling site of radon. A portable radon-thoron monitor and a portable gamma radiation detector were respectively employed to estimate the activity concentration of radon in water samples and to measure the gamma dose rate. The radon concentration was found to exhibit variability from a minimum of 2.9BqL-1 to a maximum of 197.2BqL-1, with a mean of 26.3 BqL-1 and a standard deviation of 23.3BqL-1. From a total of 85 samples, 10.6% of the samples had radon activity concentrations exceeding the permissible limits of 40BqL-1 set by the United Nations Scientific Committee on Effects of Atomic Radiations as reported by UNSCEAR (Sources and effects of ionizing radiation, 2008) and only 1.2% of the samples have radon activity concentration exceeding the permissible limits of 100BqL-1 set by the World Health Organization as reported by WHO (WHO guidelines for drinking-water quality, World Health Organization, Geneva, 2008). The mean of the annual effective dose due to inhalation for all age groups as well as the annual ingestion dose for infants and children, surpasses the World Health Organization's limit of 100μSvy-1 as reported by WHO (WHO guidelines for drinking-water quality, World Health Organization, Geneva, 2008). The observed gamma radiation dose rate in the vicinity of groundwater radon sites ranged from a minimum of 138nSvh-1 to a maximum of 250nSvh-1. The data indicated no significant correlation between the dose rate of gamma radiation and the radon levels in the groundwater. Radon concentration of potable water in the study area presents a non-negligible exposure pathway for residents. Therefore, the judicious application of established radon mitigation techniques is pivotal to minimize public health vulnerabilities.

Time-dependent variations of groundwater radon: Insights from a twelve-year study in the Baikal region, East Siberia, Russia

Time-dependent variations of 222Rn concentration (Q) in groundwater have been monitored for twelve years (2012–2023) at eight sites of groundwater discharge within the Baikal region in East Siberia, Russia. The concentrations of radioactive gas at different sites vary from 30% to 60% of average values (Qav). The sampled waters are of three groups with Qav ≈ 15 Bq/l (I), ≈30 Bq/l (II1), and ≈50 Bq/l (II2). Cluster analysis shows closest linkage between the two subgroups of group II due to similarity in the discharge mechanisms. Fourier analysis of periodic 222Rn behavior reveals major cycles of 365, 180, 126, and 30 days correlated with variations of air temperature and pressure, as well as with the patterns of groundwater discharge. In addition, radon anomalies are related with seismicity. Earthquakes are reflected in the radon field as three distinct anomaly types, occurring either subsequent to or prior to the seismic event. The anomalies responding to earthquake nucleation can be considered as precursors and used in earthquake prediction. The revealed trends make basis for a model designed to predict Q variations in groundwater of the area to 80% average efficiency. The external and internal factors that affect the concentration of radioactive gas in groundwater are linked in a hierarchic system and are classified according to the degree and type of their influence.

Evaluation of the groundwater radon concentration in the Al Jahra Governorate, Kuwait

The importance of groundwater as a necessary and vital water supply has been increasing worldwide. With the overpopulation and improving living standards in the Al Jahra Governorate, Kuwait, the demand for these products has risen quickly in recent years. Significant activity has recently emerged in relation to the inherent radon concentration in water. Fifteen groundwater samples from various locations in the Al Jahra Governorate region of Kuwait were tested for radon (Rn-222) concentrations using a RAD 7 device, which is an electronic radon detector linked to a RAD 7- H2O accessory. The obtained concentrations of Rn-222 in the ground water samples examined in our investigation ranged from 3.51 Bq.l−1 to 19.35 Bq.l−1, with a mean of 9.01 Bq.l−1. The dose of Rn-222 to the stomach caused by drinking water varied from 6.76 to 37.24 μSv/y (average: 17.35 μSv/y), and the Rn-222 dose to the lungs varied from 8.85 to 48.75 μSv/y. (average: 22.71 μSv/y). The range of the total yearly effective dosage, with a mean of 40.06 μSv/y, was 15.62–85.99 μSv/y. The annual effective dose (AED) due to intake corresponded to the concentration of one Bq. l−1 was 4.445 μSv/y. The results of the present study showed that the AED concentrations of Rn-222 in many of the groundwater samples collected from around the Al Jahra Governorate were less than the actionable thresholds advised by the USEPA, UNSCEAR, the EU Council, and the WHO (0.1 mSv/y).

Health risk assessment of radon in groundwater of a tropical river basin, SW India

Health risk assessment of radon in groundwater of a tropical river basin, SW India

Simulation of excess lifetime cancer risk due to the presence of radon in groundwater in Wamba town of Wamba local government area, Nasarawa state, Nigeria

The measurements of Radon concentration in ten groundwater (4-wells and 6-boreholes) from Wamba town of Wamba Local Government Area of Nigeria had been carried out. The annual effective dose (AED) and the Excess Lifetime Cancer Risk (ELCR) due to ingestion of the groundwater was established to ascertain the risk outcome from the samples. Radon concentration was detected using RAD7. The minimum Radon concentration was 0.146 Bql-1 while the maximum was 0.474 Bql-1 with mean average of 0.3134 Bql-1 which are within the United States Environmental Protection Agencies (USEPA) 11.1 Bq/L recommendation. Moreso, the maximum and minimum Annual Effective Dose (AEDing) was 3.5×10^(-6) and 1.10×10^(-6) Sv/yr which are also within the 0.1 mSv/yr World Health Organization (WHO) recommendation, while the maximum and minimum Excess Lifetime Cancer Risk (ELCR) was 1.44×10^(-5) and 4.50×10^(-6) respectively. Cumulative probability simulation of the Excess Lifetime Cancer Risk (ELCR) was carried out using Oracle Crystal Ball software validated by 10 and 90% percentiles. Comparison of all the results with the European Union (EU)/World Health Organization (WHO) value of 500 Bq/L recommendation revealed that all the samples analyzed have Radon concentration below the recommended limit. The average mean Radon concentration in the ten locations from Wamba Town are within the recommended levels as confirmed by the simulation results. At 10% Probability, the highest risk was found in Event center (1.26×10^(-5)) while the lowest was found in the water sample collected from Angwan dalatu (1.05×10^(-6)) while at 90% probability the highest (1.62×10^(-5)) and lowest (1.37×10^(-6)) risk was found in the same Events center and Angwan dalatu. Though there is variation in the results based on locations which means that the concentration of Radon gas depends on the geological nature of the bedrock and generally increases with the uranium concentration in the local geology. The Excess Lifetime Cancer Risk (ELCR) dose results are far lower than the UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiations) recommended maximum contamination level of 0.003875. Therefore, no indication of any likelihood of cancer incidence as a result of waterborne radon within the studied community that may demand urgent intervention from radiological point of view.

Radon and uranium content distribution in groundwater of the Eorae mountain area, Chungju, Korea

Radon and uranium content distribution in groundwater of the Eorae mountain area, Chungju, Korea

Estimation of radiation dose due to U and 222Rn in groundwater to the population of Kodagu district, Karnataka, India

Abstract Systematic studies on natural radioactivity in the groundwater of Kodagu district, India were carried out. LED fluorimetric technique to measure uranium activity and emanometric technique to measure 222Rn activity in groundwater samples were used. The concentration of U and 222Rn in the water samples was observed to vary from 0.44 to 8.81 μg L−l with a geometric mean of 2.04 μg L−l and 1.54 to 9.61 Bq L−1 with a geometric mean of 3.59 Bq L−1, respectively. The estimated concentrations of uranium and radon in groundwater were within the recommended standard limits. The radiation dose due to U and 222Rn in groundwater was estimated and the total dose due to these radionuclides was found to vary from 4.51 to 30.28 μSv y−1 which was below the prescribed safe limit of 0.1 mSv y−1 by the WHO.

Fractal Patterns in Groundwater Radon Disturbances Prior to the Great 7.9 Mw Wenchuan Earthquake, China

This study reports a fractal analysis of one-year radon in groundwater disturbances from five stations in China amidst the catastrophic Wenchuan (Mw = 7.9) earthquake of 12 May 2008 (day 133). Five techniques are used (DFA, fractal dimensions with Higuchi, Katz, Sevcik methods, power-law analysis) in segmented portions glided throughout each signal. Noteworthy fractal areas are outlined in the KDS, GS, MSS data, whilst the portions were non-significant for PZHS and SPS. Up to day 133, critical epoch DFA-exponents are 1.5≤α<2.0, with several above 1.8. The fractal dimensions exhibit Katz’s D around 1.0–1.2, Higuchi’s D between 1.5 and 2.0, and Sevcik’s D between 1.0 and 1.5. Several power-law exponents are above 1.7, and numerous are above 2.0. All fractal results of the KDS-GS-MSS are further analysed using a novel computerised methodology that locates the exact out-of-threshold fractal areas and combines the outcomes of different methods per five, four, three, and two (maximum 13 combinations) versus nineteen Mw≥ 5.5 earthquakes of the greater area. Most coincidences using different techniques are before the great Wenchuan earthquake and after the earthquake. This is not only with one method but with 13 different methods. Other interpretations are also discussed.

Determination of the radiation dose from radon ingestion and inhalation in different types of drinking water samples collected from Bethlehem province –Palestine

The objective of this study is to investigate the levels of radon gas and increase public awareness of its hazards to health in Bethlehem governorate- Palestine. The concentrations of radon-222 and radium- 226 in 79 different types of water samples were measured. The average values of radon and radium concentrations in tap water, rainwater, groundwater, and mineral water samples were 0.93 Bq/ℓ and 45.5 Bq/kg, 1.01 Bq/ℓ and 49.3 Bq/kg, 1.21 Bq/ℓ and 59.3 Bq/kg, and 0.60 Bq/ℓ and 29.2 Bq/kg, respectively. All the measured radon concentrations in the collected samples were within the limit of 11 Bq/ℓ established by UNSCEAR in 1982. The annual effective doses for ingestion and inhalation due to radon in water were calculated for adults, children, and infants using parameters introduced by UNSCEAR in 2000. The results show that there is no significant risk to public health from radon inhalation or ingestion through drinking water in the study region.

Toxicity of Radon-222 in Groundwater across Keana in Nasarawa, Nigeria

The most common supply of freshwater for drinking, irrigation, and other domestic uses is groundwater; however, because of increased radon concentrations brought on by mining activities, its quality is still a severe concern. Using a liquid scintillation detector, this study investigated the radon content, its related toxicity, and its risk to human health in the groundwater of the Keana in Nasarawa, Nigeria. Ten (10) borehole samples and five (5) well samples totaling fifteen (15) groundwater samples were taken. The results showed that the average radon concentration in water samples from Keana was 2.25 Bq/L. The mean annual effective dosage (ingestion) for adults and children in Keana was 0.016 mSv/y and 0.027 mSv/y, respectively. In Keana, the additional lifetime cancer risk per adult was 5.65 × 10–5, and per child, it was 8.79 × 10–5. The study’s radon concentration was lower than the benchmark of 11.1 Bq/L established in 1991 by the Nigerian Standard Organization and the US Environmental Protection Agency. The results of this study indicate that the level of radon is safe; as a result, people can continue farming and other activities. To reduce the risk of cancer, however, more research could be done in the area. Further research should be done by looking at additional sources in the study area in order to cover the entire zone. Further investigation should be carried out both during the dry and wet seasons because radon concentrations in groundwater alter over time due to dilution by recharge from rainfall.

Annual Effective Dose and Excess Lifetime Cancer Risk due to Ingestion and Inhalation of Radon in Groundwater of Bosso Community Minna, North-Central Nigeria

Radon in potable water has become an issue of public health concern, especially when consumed or used directly from source for domestic purposes without any pre-treatment. In this study, 222Rn concentration in 22 water samples collected from 2 groundwater sources (open wells, 12 samples and boreholes, 10 samples) in Bosso town, North central Nigeria were measured using Durridge RAD-7 radon detector with RAD-H2O accessories. 222Rn concentrations in open wells varied from 2.1±0.7 to 27.9±2.5 Bq L-1 with a mean of 10.2±1.5 Bq L-1, while that in boreholes ranged from 2.8±1.1 to 39.2±1.5 Bq L-1 with a mean value of 14.3±1.7 Bq L-1. These values are lower than the 100 Bq L-1 upper limit proposed by the European Union Commission, above which any practical intervention may be necessary. Mean annual committed effective dose to adults, children and infants from ingestion of water were 74.64, 71.58 and 53.17 \muSv y-1 respectively for the open wells and 104.24, 99.96 and 74.26 \muSv y-1 respectively for borehole water samples. Mean whole body dose due to ingestion and inhalation of waterborne radon from open wells and boreholes are 27.56 and 38.48 \muSv y-1 respectively, which are below the reference level of 0.1 mSv y-1 for potable water recommended by the World Health Organization for public safety. The excess lifetime cancer risk were 0.10 × 10-3 for the open wells and 0.13 × 10-3 for the boreholes, which are lower than the world safety limit 0.29 × 10-3. Water from the two groundwater sources investigated is therefore fit for consumption and other domestic usage from the point of view of radiation protection.

The relationship between dissolved radon and other geochemical parameters in Campi Flegrei volcanic aquifer (Southern Italy): A follow-up study

Campi Flegrei is one of the most active volcanic areas in the world and assessing the potential proxies of volcanic-related phenomena is critical. Therefore, the spatial distribution of radon and carbon dioxide in groundwater and the statistical relationships between the dissolved gases and other variables deserve further attention. Compositional data analysis (CoDA) was proposed at the end of the last century and further developed in the last decades for reliable data mining, but its potential has not been fully explored for characterization of the groundwater aquifers affected by hydrothermal activity. Based on a prospecting campaign mainly aimed at the determination of both radon and carbon dioxide in Campi Flegrei groundwater, this article explores the spatial patterns of these gases in the local aquifer system and uses a CoDA approach to extract the relevant information and to determine the meaningful geochemical associations. The results show that the spatial distribution of both dissolved gases corresponds to the hydrothermal system. The logratio transformed CO2 (aq) distinguishes bicarbonate-rich groundwater better than the raw values. Principal component analysis reveals two associations: A1) Ca2+, Mg2+, K+, SO42−, HCO3− + CO2 and pH; and A2) Na+, Cl−, As, B, Li, Rn, TDS and T. It highlights that the groundwater composition is generally influenced by two main factors: (1) meteoric water, which is modified by CO2‒rich magmatic gases in some cases; and (2) hydrothermal fluid and/or seawater. The results are in agreement with the literature and application of CoDA is recommended in future investigations because the study area is highly populated and considering the compositional nature of geochemical data might help mitigate the volcanic hazard at Campi Flegrei.

Natural radioactivity due to uranium and radon in thermal groundwaters of Central Brazil

Natural radioactivity due to uranium and radon in thermal groundwaters of Central Brazil

Hydrochemical and geological controls on dissolved radium and radon in northwestern Algeria hydrothermal groundwaters

This study presents the results of the first investigation on natural occurrence of radium and radon in Algerian thermal water systems. Activity concentrations of Rn and Ra isotopes were measured in sixteen hydrothermal springs of northwestern Algeria. Samples displayed high activities, especially for 222Rn, 224Ra and 226Ra (up to 377 × 103 Bq/m3, 730 Bq/m3 and 4470 Bq/m3, respectively). Approximately, 50% of the investigated springs displayed activities of combined long-lived Ra (226Ra + 228Ra) in excess of the maximum contaminant level (MCL) of the WHO and EPA for drinking water. Factors controlling the distribution of radionuclides in the aquifer system are investigated. The observed correlation between Ra isotope and TDS suggests that adsorption/desorption is not the dominant process controlling the distribution of Ra in waters. Our results indicate that the excess SO42− limits the concentration of dissolved Ba2+ and thereby, the elevated Ra activities in these hydrothermal systems are not simply limited by co-precipitation with BaSO4 (barite). The data shows that Ra activities are likely dominated by the recoil process of parent isotopes in the aquifer solids. The minimal abundance of clay minerals and oxides in the aquifer, in addition to thermal activities in northwestern Algeria, significantly enhances the mobilization of Ra into waters.

Can activated carbon filtration of groundwater cause radiation safety problems?

Abstract Activated carbon filtration is commonly used to remove groundwater contaminants in water utilities. During its use, also groundwater radon is adsorbed on activated carbon where it radioactively decays to Pb-210 within a few days. The intermediate stages of radioactive decay produce gamma radiation outside the filter, which can be harmful to health. In addition, EU legislation sets a clearance level of 1 kBq/kg for the Pb-210 concentration of waste, above which disposal of carbon waste can be complicated, depending on national legislation. This study focused on activated carbon filters from two groundwater plants. Measurements were made over the service lifetime of the activated carbon and included measurements of adsorption of radon from water to carbon, radiation dose rates outside the filters and Pb-210 concentrations in the carbon. The study observed a rapid decrease in the radon adsorption rate of activated carbon during the first year of use. This phenomenon has a significant effect on the concentration of Pb-210 in the activated carbon waste at the end of service life. The calculated forecast model clearly showed that the risk of exceeding the clearance level of Pb-210 increases if the radon concentration in the raw water exceeds 100 Bq/L.

Advancement of a Liquid Scintillation Counter and Semiconductor Alpha Spectroscopy Detector to Estimate the Radon Concentration in Groundwater

Radon is one of the most natural forms of radiation for human exposure. However, high-accuracy measurement of natural radon in water samples is very challenging due to the background correction, data acquisition, and sampling time. Liquid scintillation counter (LSC) and semiconductor alpha spectroscopy detectors are the most commonly used methods of determining radon concentration in water. The present study utilizes both methods to estimate radon in groundwater collected from various locations in the northeast region of Saudi Arabia. The estimated radon concentrations using Hidex 300SL are compared with a Durridge RAD7 detector to evaluate each apparatus’s abilities, advantages, and disadvantages. Both methods show radon concentrations between 0.1 and 3.20 Bq/L with an average of 0.96 Bq/L, with a standard deviation of 0.82 Bq/L. The estimated values are found to be in the safe limit recommended by the USEPA and EAEC and are far below the safe level recommended by UNSCEAR and the WHO. Comparing the estimated radon concentration using the two methods shows that although the two devices have many advantages and disadvantages based on the two different techniques, the experimental results are almost the same with experimental error.

Estimation of radon in groundwater and analysis of radon and thoron exhalation rates of the soil in Mokokchung district, Nagaland, India

The present study of the analysis of radon in groundwater and its exhalation rates in soil was carried out in 19 selected locations in Mokokchung district, Nagaland, India. The survey was carried out by employing a portable scintillation-based smart RnDuo monitor. The radon (222Rn) mass exhalation rates of the soil were found to vary from 27 mBqKg−1h−1 to 40 mBqKg−1h−1 with an average of 31 ± 0.8 mBqKg−1h−1. While the thoron (220Rn) surface exhalation rate of the soil was found to vary from 714.6 Bqm−2h−1 to 2166.6 Bqm−2h−1 with an average of 1009.9 ± 77.1 Bqm−2h−1. The radon (222Rn) in drinking water was found to vary from 1.48 BqL−1 to 2.22 BqL−1 with an average of 1.82 ± 0.04 BqL−1 and is below the world average values as set by USEPA (1991), WHO (2004) and UNSCEAR (2008). Furthermore, the total effective dose range is below the WHO (2003) recommendation.

Investigation of Radon in Groundwater and the Corresponding Human-Health Risk Assessment in Northeastern Saudi Arabia

Radon is one of the most common human exposures as a natural radiation source and can cause lung, colon, and stomach cancer. In this study, groundwater from different wells was collected from the northeastern part of Saudi Arabia. The radon concentration was estimated using an electronic portable radon detector RAD7 with a big-bottle system. The annual effective dose of radon exposure by the ingestion and inhalation of water is calculated using the radon concentration for different age groups to assess the health risk of radon exposure. The calculated annual effective doses are then compared with the international risk limit standard as international organizations direct. The estimated radon concentration for groundwater samples in the searched area was between 0.03 and 3.20 Bq/L, with an average value of 1.16 Bq/L. These estimated values are far below the safety limit set by international organizations. The annual effective dose of radon exposure for infants, children and adults ranged from 0.05 to 16.24 μSv/y, with a mean value of 5.89 μSv/y. The health risk assessed by radon exposure for infants, children and adults was found to be in the safe limit recommended by international organizations.

Seasonal and geological controls of radon (222Rn) in groundwater of Vamanapuram river basin, SW India

The study investigates the spatio-temporal variability of radon (222Rn) with respect to the geology and hydrogeology of the Vamanapuram River Basin (VRB), SW India. A total of 40 groundwater samples were collected during three seasons of 2019. RAD7, RAD-H2O accessory (Durridge Co. USA) was used to analyse 222Rn, and physico-chemical parameters were measured in situ by Horiba Laqua water quality analyser. The results show that the 222Rn activity was in the range of 640–79,940 Bq/m3 in pre-monsoon, 250–36,950 Bq/m3 in monsoon and 420–59,790 Bq/m3 in post-monsoon season and 18% of samples exceeded the permissible limit of USEPA (11,000 Bq/m3) during all seasons. Remarkably, the samples exceeding the permissible limit of 222Rn were associated with khondalitic rocks with notable amount of uranium-bearing minerals and NW-SE trending lineaments, the most active type of lineament in the study area. The study shows the considerable influence of seasons and the highest activities were found during pre-monsoon compared to the other two seasons.