Determination of 222RN level in groundwater using a Rad7 detector in the Bathinda district of Punjab, India

Radon activity and their radiological doses in drinking water of Chitradurga district, Karnataka, India

In this investigation, radon activity concentration, inhalation and ingestion doses due to intake of radon in drinking water have been estimated in the Chitradurga district drinking water by using radon Emanometry technique. The average radon concentrations vary from 1.81 ± 0.11 to 300.33 ± 4.56 Bql-1 with a mean value of 56.01 ± 2.44 Bql-1. Most of the radon concentration levels are within the World Health Organization (WHO) and European Union (EU) commission recommended level of 100 Bql-1. About 70% of the drinking water had radon concentration level higher than the United States Environmental Protection Agency (USEPA) recommended Maximum Contamination Limit (MCL) of 11.1 Bql-1. The annual ingestion dose varies from 0.38 to 63.03 μSvy-1 with an average value of 11.75 μSvy-1. The estimated annual ingestion dose is well within the WHO recommended reference level of 100 μSvy-1.

ASSESSMENT OF ANNUAL EFFECTIVE DOSE DUE TO INHALATION AND INGESTION OF RADON FROM GROUNDWATER AT THE SOUTHEAST COASTAL AREA, BANGLADESH

Naturally occurring radon-222 was evaluated for its use in estimating annual effective dose exposure in groundwater samples of the southeast coastal area of Bangladesh. On-site radon concentration was measured in groundwater using AlphaGUARD PQ2000 PRO (Saphymo, Germany) radon monitor. The measured values range 0.36-15.70 Bq per l, which lies within the safe limit of 4-40 Bq per l recommended by UNSCEAR. On the contrary, few samples show radon concentration above the safe limit of 11.1 Bq per l recommended by USEPA. The mean annual effective doses due to ingestion and inhalation resulting from radon in groundwater vary from 0.99 to 42.87 μSv per y with an average value of 12.45 μSv per y, which is far below the safe limit 100 μSv per y recommended by WHO and EU. Results reveal that there is no significant public health hazard due to radon ingestion and inhalation from groundwater in the study area.

RADON CONCENTRATION IN SOIL AND GROUNDWATER OF WEST COASTAL AREA, BANGLADESH

On-site radon concentration has been measured in soil gas and ground water using AlphaGUARD PQ2000 PRO (Saphymo, Germany) radon monitor at the west coastal area of Bangladesh. The measured radon concentration in ground water samples is in the range of 1.41 ± 0.29 to 3.2 ± 0.59 Bq/l with the mean value of 2.33 ± 0.50 Bq/l, which lies within the safe limit recommended by UNSCEAR (2008). The total annual effective dose estimated due to radon concentration in ground water ranges from 3.85 to 8.74 μSv/y with the mean value of 6.37 μSv/y, which is lower than the safe limit set by WHO (2004) and EU (1998). In soil samples, radon concentration has been measured at three different depths (0, 20 and 40 cm) in each location. The highest and the lowest concentrations are 4790 ± 51 and 10 ± 04 Bq/m3 at 40 and 0 cm (surface) depth, respectively, which lie within the natural background levels.

Groundwater chemistry and health risks associated with nitrate intake in Hailun, northeast China

In order to quantify the hydrochemical characteristics of groundwater in Hailun, analyze the hydrochemical process, and evaluate its health risks associated with nitrate intake, 77 shallow groundwater samples were collected and analyzed. The results show that groundwater in the study area is weakly acidic and groundwater chemical type was dominated by HCO₃-Ca, HCO₃•Cl-Ca, HCO₃-Ca•Na and HCO₃•Cl-Ca•Na. Rock weathering and dissolution, ion exchange, and human activities are the main reasons affecting the chemical composition of shallow groundwater in Hailun. The weathering and dissolution process of silicate under weakly alkaline conditions is the source of Na. The dissolution of calcite, dolomite, and gypsum are the main form of water-rock interaction. Results of health risk assessment show that the HQ value for adult males, adult females, children, and infants were in range of 0-1.52, 0-1.75, 0-3.58 and 0-6.08, respectively, and with a mean value of 0.19, 0.22, 0.44, 0.75, respectively. The harm of NO₃ pollution is in the order of infant > child > adult female > adult male. The results of this study made local governments pay attention to drinking water safety issues for local residents.

Distribution and correlation of radon and uranium and associated hydrogeochemical processes in alluvial aquifers of northwest India

The spatial and vertical distributions of radon and uranium are evaluated in relation to the hydrogeology, geomorphology, and hydrochemistry of southwest Punjab. Radon activity of the groundwater ranges from 580 to 3633 Bq/m³ (shallow groundwater 580 to 2438 Bq/m³ and deep groundwater 964 to 3633 Bq/m³), and uranium concentration varies from 24.4 to 253 μg/L (shallow groundwater 24.4 to 253 μg/L and deep groundwater 27.6 to 76.3 μg/L). Shallow groundwater shows higher U concentration compared with deeper ones, which can be attributed to the presence of dissolved oxygen (DO) and NO₃^- as oxidants and HCO₃^- as stabilizing agent in shallow zone. Unlike uranium, the radon activities were found to be similar in both shallow and deep groundwater. Rn_excess over secular equilibrium was used to confirm the possibility of additional sources of radon, such as secondary minerals present in the subsurface. Surface manifestations show significant influence on radon and uranium distributions in the shallow zone but not in deep zone due to limited hydraulic connectivity. Depth profiles and correlations of radon and uranium with trace elements and hydrochemical parameters indicate that groundwater exhibits different redox characteristics in shallow (younger and oxidizing) and deep zones (older and reducing). The present study provides critical information that can be helpful for planning sustainable groundwater development in this region and other similar regions without contaminating the relatively safer deep aquifers.

Assessment of radioactivity from groundwater samples from selected areas of Western Black Sea Region, Turkey

In this study, radon concentration measurements and chemical analyses of groundwater samples were performed in four sampling locations of Bartın Province of Western Black Sea Region, Turkey. 222Rn analysis was carried out in groundwater samples with liquid scintillation counting system in accordance with ASTM D5072 standard. The pH, total hardness, alkalinity and dissolved oxygen parameters of the groundwater samples were also determined. The radon concentrations for the water samples ranged between <3.00 Bq/L–12.03 Bq/L. Thirty eight percentage of the samples slightly exceeded the permissible limit of 11.1 Bq/L specified by USEPA for drinking waters. The annual effective doses of groundwater samples were calculated in the range of 7.41–30.74 μSv/y for ingestion of water (E w.Ig ), and in the range of 7.31–30.31 μSv/y for inhalation of radon released from water (Ew.Ih ). The total calculated annual effective doses due to ingestion and inhalation were found to be below the limit value of 100 μSv/y specified by the World Health Organization (WHO). The radioactivity measurement results significantly varied for three sampling points but not for one sampling point on two different measurement dates, which is attributed to the differences in geological structure. The chemical analysis results, except for total hardness in two sampling points, were within the permissible limits specified by international standards.

Indoor and tap water radon (222Rn) concentration measurements at Giresun University campus areas

In this study, indoor (air) and tap water Radon (²²²Rn) measurements were performed at various campus areas of Giresun University. The measurement and analysis results were compared with the values recommended by international and national organizations and those reported in literature studies. The measured and calculated values were found to be under the recommended limits. Also, annual effective dose values were evaluated to determine the annual radon exposure of an individual working in the measurement area. Indoor radon concentration values measured by CR-39 detectors were in the range of 76 Bq/m³-504 Bq/m³ and the mean concentration value was obtained as 193.7 Bq/m³. The radon concentrations in tap water samples were found to be in the range of 0.98 Bq/L-27.28 Bq/L. The annual mean effective doses (E_Wig) of drinking water samples were calculated in the range of 9.9-150.4 (μSv/y) for ingestion and 0.97-14.84 (μSv/y) for inhalation calculations. Excess life time cancer risk (ELCR) was estimated as 0.54%. Radon dose rate in terms of mean annual working level month was calculated as 0.246 WLM/year. The study was performed with a view to contribute to further studies in the related field and constitute a basis for the measurements conducted in this area.

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 in spring waters in the south of Catalonia

Spring waters in the south of Catalonia were analysed to determine the (222)Rn activity in order to be able to establish a correlation between the obtained values with the geology of the area of origin of these samples, and also estimate the potential health risks associated with (222)Rn. Most of the analysed samples (90%) show (222)Rn activities lower than 100Bq/L (exposure limit in water recommended by the World Health Organisation and EU directive 2013/51/EURATOM). However, in some cases, the activity values found for this isotope exceeded those levels and this can be attributed to the geology of the area where the spring waters are located, which is predominantly of granitic characteristics. To verify the origin of the radon present in the analysed samples, the obtained activity values were compared with the activities of its parents ((226)Ra, (238)U and (234)U). Finally, we have calculated the annual effective dose from all the radionuclides measured in spring water samples. The results showed that the higher contribution due to spring water ingestion come from (222)Rn and (226)Ra. The resulting contribution to the annual effective dose due to radon ingestion varies between 10.2 and 765.8 μSv/y, and the total annual effective dose due to his parents, (226)Ra, (234)U and (238)U varies between 0.8 and 21.2 μSv/y so the consumption of these waters does not involve any risks to population due to its natural radioactivity content.

Radon concentrations in drinking water in Beijing City, China and contribution to radiation dose

(222)Rn concentrations in drinking water samples from Beijing City, China, were determined based on a simple method for the continuous monitoring of radon using a radon-in-air monitor coupled to an air-water exchanger. A total of 89 water samples were sampled and analyzed for their (222)Rn content. The observed radon levels ranged from detection limit up to 49 Bq/L. The calculated arithmetic and geometric means of radon concentrations in all measured samples were equal to 5.87 and 4.63 Bq/L, respectively. The average annual effective dose from ingestion of radon in drinking water was 2.78 μSv, and that of inhalation of water-borne radon was 28.5 μSv. It is concluded that it is not the ingestion of waterborne radon, but inhalation of the radon escaping from water that is a substantial part of the radiological hazard. Radon in water is a big concern for public health, especially for consumers who directly use well water with very high radon concentration.