Radon concentration in groundwater of Varahi and Markandeya river basins, Karnataka State, India

Geographical distribution of radon and associated health risks in drinking water samples collected from the Mulazai area of Peshawar, Pakistan

Geospatial methods, such as GIS and remote sensing, map radon levels, pinpoint high-risk areas and connect geological traits to radon presence. These findings direct health planning, focusing tests, mitigation, and policies where radon levels are high. Overall, geospatial analyses offer vital insights, shaping interventions and policies to reduce health risks from radon exposure. There is a formidable threat to human well-being posed by the naturally occurring carcinogenic radon (222Rn) gas due to high solubility in water. Under the current scenario, it is crucial to assess the extent of 222Rn pollution in our drinking water sources across various regions and thoroughly investigate the potential health hazards it poses. In this regard, the present study was conducted to investigate the concentration of 222Rn in groundwater samples collected from handpumps and wells and to estimate health risks associated with the consumption of 222Rn-contaminated water. For this purpose, groundwater samples (n = 30) were collected from handpumps, and wells located in the Mulazai area, District Peshawar. The RAD7 radon detector was used as per international standards to assess the concentration of 222Rn in the collected water samples. The results unveiled that the levels of 222Rn in the collected samples exceeded the acceptable thresholds set by the US Environmental Protection Agency (US-EPA) of 11.1 Bq L-1. Nevertheless, it was determined that the average annual dose was below the recommended limit of 0.1 mSv per year, as advised by both the European Union Council and the World Health Organization. In order to avoid the harmful effects of such excessive 222Rn concentrations on human health, proper ventilation and storage of water in storage reservoirs for a long time before use is recommended to lower the 222Rn concentration.

Radon concentration in spring water as an indicator of seismic activity: a case study of the Muzaffarabad Fault in Pakistan

Radon and its progenies found in water indicate the existence of seismically active faults in the region. However, exposure to high levels of radon can also result in radiation-related health risks. This study focuses on radon-based active tectonic studies along the Muzaffarabad Fault in the core of the Hazara-Kashmir Syntaxis (HKS), NW Himalayas, Pakistan. In this study, spring water samples were collected along roadside of Jhelum Valley and in close proximity to the Muzaffarabad Fault in Pakistan using Radon Thoron Monitor (RTM1688-2). The results of the study showed that the radon concentrations in the water samples ranged from 1.895 to 17.097 Bq/l. The study found that the highest radon concentration was observed in the samples collected closest to the fault, while the lowest concentration was observed in the samples collected further away. The statistical analysis between the radon concentration and the distance from the fault showed a strong inverse relationship (R2=0.73). The study also found that 68% of the sampling sites had radon concentrations that exceeded the maximum contamination level (MCL) set by the US Environmental Protection Agency (EPA). The higher radon concentrations in the springs water suggest the probability of earthquake, which in turn poses potential health risks for the local population. The findings suggest that the measurement of radon concentration in water can be used as a tool for identifying seismically active faults in the region.

Seasonal effects on hydrochemistry, microbial diversity, and human health risks in radon-contaminated groundwater areas

Groundwater is an important human resource. Daejeon in South Korea faces severe water quality issues, including radon, uranium, and fluoride pollution, all of which pose health risks to humans. With climate change, threats to potable water, such as heavy rain and typhoons, have become common. Therefore, examining the seasonal effects on groundwater quality and resultant health risks is important for understanding the mechanisms of different hydroclimatological conditions to enable the implementation of sustainable management plans in radon-contaminated groundwater areas. However, this issue has not yet been studied. To bridge this gap, in this study, major ions and microbial community structures were employed and groundwater quality index (GWQI) were calculated with hazard index based on limits set by the World Health Organization (WHO) to investigate the hydrochemical characterization and to assess pollution levels. The results showed that the rainy season had distinct hydrochemical characteristics with high correlations between radon and fluoride, and most groundwater samples collected after the typhoon had characteristics similar to those collected during the dry season, owing to the flow path. Furthermore, the microbial diversity and hazard quotient (HQ) values of fluoride revealed that pollution worsened during the dry season. All of the calculated effective dose values of radon exceeded the threshold limit set by the WHO, despite the low GWQI. Infants and children were particularly susceptible to radon-contaminated groundwater. The statistical results of self-organizing map (SOM) suggested that radon analysis was sufficient for public health intervention in the rainy season; however, in the dry season, combined analyses of radon, fluoride, and microbial diversity played important roles in health risk assessment. Our study presents a comprehensive understanding of radon-contaminated groundwater characteristics under seasonal effects and can serve as a reference for other similar zones to provide significant insights into the effective management of radon contamination.

Assessment of Radon gas concentration in Tap water supply of Haditha Town / west Al-Anbar Governorate / Iraq

The current study was performed to estimate Radon concentration in the tap water and annual effective dose in 22 water samples from three districts in Haditha city (Haditha center, Haqlaniyah and Barowana) in addition to Euphrates river. the results show that overall concentration of radon 226 in drinking water in Haditha city was ranged (0.0091 – 0.031 Bq L−1). Also, the annual effective dose of radon 226 was calculated, The highest was 0.113166 μSv/y, while the lowest was 0.03322 μSv/y. The rank order of drinking water resources in Haditha region based on the concentration of radon 226 was Euphrates river > Haditha > Barwana > Haglanyah. The overall concentration of radon 226 in drinking water in Haditha city was lower than WHO and EPA standard limits.

Factors controlling the distribution of radon (222Rn) in groundwater of a tropical mountainous river basin in southwest India

Studies on occurrence of radon in the environment are receiving growing attention worldwide due to its adverse impact on human health. Despite that, the dissolved radon in water is found to be a useful tracer in many hydrogeological studies. Although, several studies focused on the occurrence of high ²²²Rn in groundwater, the processes responsible for its variation is still not well understood. Hence, an attempt has been made in the present study to elucidate the underlying factors influencing the abundance ²²²Rn in hard rock (gneissic) aquifers of Karamana River Basin, southwest India. ²²²Rn in groundwater was analyzed in 71 dug wells during the pre-monsoon period of 2017. A large variability in ²²²Rn activities (170-68,350 Bq/m³) was noticed in groundwater and high activities were mainly seen in the khondalite formation. No significant dependencies between ²²²Rn activity and depth to water table, groundwater temperature and electrical conductivity were observed. However, majority of the presence of high ²²²Rn activity in groundwater matches with the location of lineaments. Furthermore, radium content in the host rock, degree of weathering and fracturing and the emanation coefficient of the rock were found to have an important bearing on the occurrence of radon in groundwater. The underlying factors influencing the abundance of radon in hard rock aquifers were also conceptualized. Thus, the study highlights the usefulness of ²²²Rn as a potential tool in delineating the macro-structural features like fractures/lineaments that are significant repositories of groundwater, which could be explored for groundwater development in hard rock terrains.

MEASUREMENT OF RADON ACTIVITY CONCENTRATION IN UNDERGROUND WATER OF BURETI SUB-COUNTY OF KERICHO COUNTY KENYA

The activity concentration of radon in underground water of Bureti sub-county was measured using liquid scintillating counter device. The average radon activity concentration in all the water samples was 12.41 Bql-1. The maximum and minimum activity concentrations of radon were 22.5 and 4.57 Bql-1, respectively. In total, 53% of the total samples analysed had radon concentration levels above the US Environmental Protection Agency-recommended limit of 11.1 Bql-1. The annual dose received by an individual as a result of waterborne radon was determined according to the United Nations Scientific Committee on the Effect of Atomic Radiation reports and was found to be 33.23 𝜇Svy-1. All the samples recorded a value <100 𝜇Svy-1 recommended by the World Health Organization and the European Union council.

Radon concentration in drinking water and soil after the September 24, 2019, Mw 5.8 earthquake, Mirpur, Azad Jammu, and Kashmir: an evaluation for potential risk

Radon (²²²Rn), a radioactive gas resulted from the natural decay of other radioactive elements, pose a threat to the exposed human population. Radon gas emits along the seismically active faults and increased the ²²²Rn contamination in sorrounding water and soil. This study investigated the concentration of ²²²Rn in drinking water and soil after the September 24, 2019, Mw 5.8 earthquake, Mirpur District, Azad Jammu, and Kashmir (AJK). For this purpose, water (n = 24) samples were collected from the bore wells of orderly located houses and soil field sampling (n = 12) along with the NE-SW directions of fracture in the Mirpur District. Determined ²²²Rn in drinking water surpassed the maximum contamination level (MCL, 11.1 kBq/m³) set by the US Environmental Protection Agency (US EPA) in 83%, 50%, and 33% of the sampling point at the site I, site II, and site III, respectively. However, that of soil ²²²Rn concentration was observed with the normal range (10-50 kBq/m³). Potential exposure of ²²²Rn consumption in drinking water was the mean effective dose through ingestion (E_Wing, 0.003 ± < 0.001 mSv/a), the effective dose for inhalation (E_WInh, 0.038 ± 0.002 mSv/a), and the total effective dose of human (E_WT, 0.041 ± 0.002 mSv/a). Exposure values along with the rupture showed multifold higher risk values (up to 4 times) compared to background sites. These values were observed within the limits (0.1 mSv/a) set by World Health Organization (WHO); however, surpassed the thresholds of the United Nations Scientific Committee on the effects of atomic radiations (UNSCEAR) for all exposure pathways. This study concluded that groundwater in the close vicinity should be avoided or boiled before used for drinking purposes.

INGESTION AND INHALATION DOSES DUE TO INTAKE OF RADON IN DRINKING WATER SAMPLES OF AMRITSAR PROVINCE, PUNJAB, INDIA

In the present investigation, the ingestion and inhalation dosage for the particular body organs in light of the intake of radon through ground water utilised by the occupants have been assessed in the different villages of the Upper Bari Doab region of Amritsar province, India using an electrostatic collection type radon monitor (RAD7) analyzer with RAD-H2O accessory. The mean radon activity level in water was seen to be 8.34 ± 2.99 Bql-1. The newborn children have higher radiation dosage than the other age groups because of their high dosage transformation factors. However, the radiation dosage received by all different age groups significantly less than the UNSCEAR and WHO suggested a level of 100 μSv y-1. The annual effective dosage for the diverse body organs because of the intake of radon was moreover ascertained and found the maximum dosage for lungs than other organs. The radiation dosage received by bronchial epithelium by the means of inhalation was likewise high when contrasted with that by stomach walls through ingestion.

EVALUATION OF A RADON AIR MONITOR IN THE MEASUREMENT OF RADON CONCENTRATION IN WATER IN COMPARISON WITH A LIQUID SCINTILLATION COUNTER

The World Health Organisation (WHO) recommends that the concentration of radon in water should be no more than 100 kBq m-3 (100 BqL-1) and the Codex Alimentarius Commission states that the limit of quantification (LOQ) of a method should be no more than one-fifth of this value. In this study, a degassing method with an RAD7 device was used to measure radon concentrations in water, compared to a liquid scintillation counter (LSC) method used as the reference, to investigate whether the numerical value of the LOQ of this method was more than 1/5 (20 kBq m-3) of 100 kBq m-3. The degassing method with leak prevention was shown to reach a target value of 20 kBq m-3 or less under a relative humidity of 6% or lower in the chamber of the RAD7 device. Accordingly, the RAD7 degassing method with leak prevention can be used to accurately measure radon concentrations in water within the guidance level set out by the WHO.

Assessment of radon concentration and heavy metal contamination in groundwater of Udhampur district, Jammu & Kashmir, India

Radon concentration was measured in water samples of 41 different locations from Udhampur district of Jammu & Kashmir, India, by using RAD7 and Smart RnDuo monitor. The variation of radon concentration in water ranged from 1.44 ± 0.31 to 63.64 ± 2.88 Bq L^-1, with a mean value of 28.73 Bq L^-1 using RAD7 and 0.64 ± 0.28 to 52.65 ± 2.50 Bq L^-1, with a mean value of 20.30 Bq L^-1 using Smart RnDuo monitor, respectively. About 17.07% of the studied water samples recorded to display elevated radon concentration above the reference range suggested by United Nation Scientific Committee on the Effects of Atomic Radiations (UNSCEAR). The mean annual effective dose of these samples was determined, and 78.95% samples were found to be within the safe limits set by World Health Organisation (WHO) and European Council (EU). The study revealed good agreement between the values obtained with two methods. Heavy metals (Zn, Cd, Fe, Cu, Ni, As, Hg, Co, Pb and Cr) were determined in water samples by microwave plasma atomic emission spectrometer, and their correlation with radon content was also analysed.

Radon concentration in drinking water and supplementary exposure in Baita-Stei mining area, Bihor county (Romania)

The radon concentration was measured in the drinking water of public water supply and private wells located in the mining area of BăiŢa-Ştei, Bihor County, Romania. The measurements were performed using the LUK-VR system based on radon gas measurement with Lucas cell. The results show that the radon concentrations are within the range of 1.9-134.3 kBq m(-3) with an average value of 35.5 kBq m(-3) for well water, 18.5 kBq m(-3) for spring water and 6.9 kBq m(-3) for tap water. Comparing with previous data from the whole of Transylvania, the average value is two times higher, proving this zone to be a radon-prone area. From the results of this study the effective dose to the population is between 4.78 and 338.43 µSv y(-1). These doses are within the recommended limits of the world organisations.

Measurement of (222)Rn concentration in drinking water in Sakarya, Turkey

In this paper, the first measurement of (222)Rn concentrations in drinking water from wells, springs and bottled waters in the city of Sakarya, Turkey was presented. The measurements were performed using RAD 7, a solid-state alpha detector, with RAD H2O (radon in water) accessory manufactured by Durridge Company, Inc. The measured activity concentrations ranged from 1.98 to 20.80 Bq l(-1) with an average value of 9.05 Bq l(-1) for well water, from 0.75 to 59.65 Bq l(-1) with an average value of 13.78 Bq l(-1) for spring water and from 0.75 to 22.8 Bq l(-1) with an average value of 5.41 Bq l(-1) for bottled water. Although these results indicated relatively high (222)Rn concentrations compared with that from other parts of the Turkey, they are still below the World Health Organization recommended level of 100 Bq l(-1) for radon. Using the measured activities of (222)Rn, the age-dependent associated committed effective doses due to the ingestion of (222)Rn as a consequence of direct consumption of drinking water were calculated. The committed effective doses from (222)Rn were estimated to range from 2.59 to 205.97 µSv y(-1), from 1.55 to 123.28 µSv y(-1) and from 1.31 to 104.48 µSv y(-1) for age groups 1-2, 8-12 and >17 y, respectively.