Lessons learnt on the impact of an unprecedented soil decontamination program in Fukushima on contaminant fluxes.

In the context of elevated concerns related to nuclear accidents and warfare, the lessons learnt from the Fukushima Daiichi Nuclear Power Plant accident in 2011 are important. In particular, Japanese authorities implemented an ambitious decontamination program to reduce the air dose rate in order to facilitate the return of the local inhabitants to previously evacuated areas. This approach contrasts the strategy adopted in Chernobyl, where the most contaminated areas remain off limits. Nonetheless, the effectiveness of the Japanese decontamination strategy on the dispersion of radioactive contaminant fluxes across mountainous landscapes exposed to typhoons has not been quantified. Based on the unique combination of river monitoring and modeling in a catchment representative of the most impacted area in Japan, we demonstrate that decontamination of 16% of the catchment area resulted in a decrease of 17% of sediment-bound radioactive fluxes in rivers. Decontamination operations were therefore relatively effective, although they could only be conducted in a small part of the area due to the dominance of steep forested slopes. In fact, 67% of the initial radiocesium contamination was calculated to remain stored in forested landscapes, which may contribute to future downstream radiocesium dispersion during erosive events. Given that only a limited proportion of the initial population had returned in 2019 (~30%), it raises the question as to whether decontaminating a small percentage of the contaminated area was worth the effort, the price, and the amount of waste generated?

Microbiome analysis of the restricted bacteria in radioactive element-containing water at the Fukushima Daiichi Nuclear Power Station.

A major incident occurred at the Fukushima Daiichi Nuclear Power Station following the tsunami triggered by the Tohoku-Pacific Ocean Earthquake in March 2011, whereby seawater entered the torus room in the basement of the reactor building. Here, we identify and analyze the bacterial communities in the torus room water and several environmental samples. Samples of the torus room water (1 × 109 Bq137Cs/L) were collected by the Tokyo Electric Power Company Holdings from two sampling points between 30 cm and 1 m from the bottom of the room (TW1) and the bottom layer (TW2). A structural analysis of the bacterial communities based on 16S rRNA amplicon sequencing revealed that the predominant bacterial genera in TW1 and TW2 were similar. TW1 primarily contained the genus Limnobacter, a thiosulfate-oxidizing bacterium. γ-Irradiation tests on Limnobacter thiooxidans, the most closely related phylogenetically found in TW1, indicated that its radiation resistance was similar to ordinary bacteria. TW2 predominantly contained the genus Brevirhabdus, a manganese-oxidizing bacterium. Although bacterial diversity in the torus room water was lower than seawater near Fukushima, ~70% of identified genera were associated with metal corrosion. Latent environment allocation-an analytical technique that estimates habitat distributions and co-detection analyses-revealed that the microbial communities in the torus room water originated from a distinct blend of natural marine microbial and artificial bacterial communities typical of biofilms, sludge, and wastewater. Understanding the specific bacteria linked to metal corrosion in damaged plants is important for advancing decommissioning efforts. IMPORTANCE: In the context of nuclear power station decommissioning, the proliferation of microorganisms within the reactor and piping systems constitutes a formidable challenge. Therefore, the identification of microbial communities in such environments is of paramount importance. In the aftermath of the Fukushima Daiichi Nuclear Power Station accident, microbial community analysis was conducted on environmental samples collected mainly outside the site. However, analyses using samples from on-site areas, including adjacent soil and seawater, were not performed. This study represents the first comprehensive analysis of microbial communities, utilizing meta 16S amplicon sequencing, with a focus on environmental samples collected from the radioactive element-containing water in the torus room, including the surrounding environments. Some of the identified microbial genera are shared with those previously identified in spent nuclear fuel pools in countries such as France and Brazil. Moreover, our discussion in this paper elucidates the correlation of many of these bacteria with metal corrosion.

Subsurface Transport of Plutonium in Organic and Aqueous Acidic Processing Wastes at the Hanford Site, USA.

Over 4 million liters of mixed acidic (∼pH 2.5), high ionic strength (∼5 M nitrate) plutonium (Pu) processing waste were released into the 216-Z-9 (Z-9) trench at the Hanford Site, USA, and trace Pu has migrated 37 m below the trench. In this study, we used flowthrough columns to investigate Pu transport in simplified processing waste through uncontaminated Hanford sediments to determine the conditions that led to Pu migration. In low pH aqueous fluids, some Pu breakthrough is observed at pH < 4, and increased Pu transport (14% total Pu breakthrough) is observed at pH < 2. However, Pu migrates in organic processing solvents through low pH sediments virtually uninhibited with approximately 94 and 86% total Pu breakthrough observed at pH 1 and pH 3, respectively. This study demonstrates that Pu migration can occur both with and without organic solvents at pH < 4, but significantly more Pu can be transported when partitioned into organic processing solvents. Our data suggest that under acidic conditions (pH < 4) in the vadose zone beneath the Z-9 trench, Pu present in organic processing solvents moved relatively unhindered and may explain the historical downward migration of Pu tens of meters below the Z-9 trench.

Open-Framework Vanadate as Efficient Ion Exchanger for Uranyl Removal.

The elimination of uranium from radioactive wastewater is crucial for the safe management and operation of environmental remediation. Here, we present a layered vanadate with high acid/base stability, [Me2NH2]V3O7, as an excellent ion exchanger capturing uranyl from highly complex aqueous solutions. The material possesses an indirect band gap, ferromagnetic characteristic and a flower-like morphology comprising parallel nanosheets. The layered structure of [Me2NH2]V3O7 is predominantly upheld by the H-bond interaction between anionic framework [V3O7]nn- and intercalated [Me2NH2]+. The [Me2NH2]+ within [Me2NH2]V3O7 can be readily exchanged with UO22+. [Me2NH2]V3O7 exhibits high exchange capacity (qm = 176.19 mg/g), fast kinetics (within 15 min), high removal efficiencies (>99%), and good selectivity against an excess of interfering ions. It also displays activity for UO22+ ion exchange over a wide pH range (2.00-7.12). More importantly, [Me2NH2]V3O7 has the capability to effectively remove low-concentration uranium, yielding a residual U concentration of 13 ppb, which falls below the EPA-defined acceptable limit of 30 ppb in typical drinking water. [Me2NH2]V3O7 can also efficiently separate UO22+ from Cs+ or Sr2+ achieving the highest separation factors (SFU/Cs of 589 and SFU/Sr of 227) to date. The BOMD and DFT calculations reveal that the driving force of ion exchange is dominated by the interaction between UO22+ and [V3O7]nn-, whereas the ion exchange rate is influenced by the mobility of UO22+ and [Me2NH2]+. Our experimental findings indicate that [Me2NH2]V3O7 can be considered as a promising uranium scavenger for environmental remediation. Additionally, the simulation results provide valuable mechanistic interpretations for ion exchange and serve as a reference for designing novel ion exchangers.

Uranium contamination of bivalve Mytilus galloprovincialis, speciation and localization.

Uranium is a natural radioelement (also a model for heavier actinides), but may be released through anthropogenic activities. In order to assess its environmental impact in a given ecosystem, such as the marine system, it is essential to understand its distribution and speciation, and also to quantify its bioaccumulation. Our objective was to improve our understanding of the transfer and accumulation of uranium in marine biota with mussels taken here as sentinel species because of their sedentary nature and ability to filter seawater. We report here on the investigation of uranium accumulation, speciation, and localization in Mytilus galloprovincialis using a combination of several analytical (Inductively Coupled Plasma Mass Spectrometry, ICP-MS), spectroscopic (X ray Absorption Spectroscopy, XAS, Time Resolved Laser Induced Fluorescence Spectroscopy, TRLIFS), and imaging (Transmission Electron Microscopy, TEM, µ-XAS, Secondary Ion Mass Spectrometry, SIMS) techniques. Two cohorts of mussels from the Toulon Naval Base and the Villefranche-sur-Mer location were studied. The measurement of uranium Concentration Factor (CF) values show a clear trend in the organs of M. galloprovincialis: hepatopancreas â‰« gill > body ≥ mantle > foot. Although CF values for the entire mussel are comparable for TNB and VFM, hepatopancreas values show a significant increase in those from Toulon versus Villefranche-sur-Mer. Two organs of interest were selected for further spectroscopic investigations: the byssus and the hepatopancreas. In both cases, U(VI) (uranyl) is accumulated in a diffuse pattern, most probably linked to protein complexing functions, with the absence of a condensed phase. While such speciation studies on marine organisms can be challenging, they are an essential step for deciphering the impact of metallic radionuclides on the marine biota in the case of accidental release. Following our assumptions on uranyl speciation in both byssus and hepatopancreas, further steps will include the inventory and identification of the proteins or metabolites involved.

Molten salt mediated single-step synthesis of reusable nanostructured CaTiO3 for the removal and recovery of Sr2+: A potential adsorbent for the contaminated water bodies.

The facile synthesis approach for the adsorbent preparation and recyclability during decontamination of radioactive pollutants is a significant concern in water treatment. The objective of this study is to, synthesis via solid-state reaction of the nanostructured CaTiO3 for the removal and recovery of strontium (Sr2+) from the various water sources. The influence of the adsorption-dependent parameters including, initial concentration, adsorbent dose, pH, contact time and co-existing ions interference were investigated. The prepared adsorbent was characterized by different analytical techniques like FT-IR, SEM with EDAX, TEM, TGA-DTG, Powder XRD and BET surface analysis. The kinetic models were also used, and according to the kinetic models, a pseudo-second-order kinetic model (R2 = 0.999) was better fitted to the adsorption of Sr2+ ions onto CaTiO3 rather than pseudo-first-order kinetics, which could properly represent the observed adsorption of Sr2+. For the isotherm study, the results are best fitted to the Langmuir isotherm model (R2 = 0.98) with a maximum adsorption capacity of 102.04 mg/g. The common ions (Na+, Mg2+, Ca2+, and K+) and Sr2+ having a concentration of 1:2, 1:3, and 1:4, where 82.8, 79.5, and 68.2 % removal was achieved of Sr2+ in each respective matrix. In addition, the adsorption and corresponding recovery and removal for the different Sr2+spiked matrices in deionized water, tap water, well water, lake water, and seawater were investigated with 97, 65.6, 76.5, 73.9 and 17.8 % removal respectively. Also, the CaTiO3 showed excellent recyclability with minimal loss even after 5 consecutive recyclability cycles and >90% removal of strontium achieved. Hence, prepared nanostructured CaTiO3 could be considered a promising adsorbent for the removal and recovery of Sr2+ions from contaminated water bodies.

Unraveling the mechanism of iodate adsorption by anthocyanin-rich fruit waste as green adsorbents for Applications of radioactive iodine remediation in water environment.

In aquatic settings, radioactive iodine from nuclear waste can exist as iodate (IO3-). This study explored the efficiency and mechanism of IO3- adsorption by minimally modified anthocyanin-based adsorbents. Pomegranate peels and mangosteen pericarps were selected from an initial screening test and could remove over 70% of 10 mg/L IO3-. The adsorbents yielded adsorption capacity (q) of 9.59 mg/g and 2.31 mg/g, respectively, at room temperature. At 5 °C, q values increased to 14.5 and 5.13 mg/g, respectively. Pomegranate peels showed superior performance, with approximately 4 times the anthocyanin content of mangosteen pericarps. Both adsorbents took 120 min to reach adsorption equilibrium, and no desorption was observed after 8 days (I-131 half-time). Confirmation of physisorption was indicated by the fit of the pseudo-first-order reaction model, negative entropy (exothermic), and negative activation energy (Arrhenius equation). IO3- inclusion was confirmed through adsorbent surface modifications in scanning electron microscope images, the increased iodine content post-adsorption in energy-dispersive X-ray spectroscopy analysis, and alterations in peaks corresponding to anthocyanin-related functional groups in Fourier transform infrared spectroscopy analysis. X-ray absorption near-edge spectroscopy at 4564.54 eV showed that iodine was retained in the form of IO3-. Through the computational analysis, electrostatic forces, hydrogen bonds, and π-halogen interactions were deduced as mechanisms of IO3- adsorption by anthocyanin-based adsorbents. Anthocyanin-rich fruit wastes emerged as sustainable materials for eliminating IO3- from water.

Internal dose rate due to intake of uranium and thorium by fish from a dam reservoir associated with a uranium mine in Brazil.

Uranium mining can cause environmental impacts on non-human biota around mine sites. Because of this, the reduction in non-human biota exposure becomes an important issue. Environmental radioprotection results from the evolution of human radioprotection; it is based on dose rate to non-human biota and uses, as a biological target, and has harmful effects on populations. In the present study, a flooded impoundment created following dam construction in a uranium mine plant undergoing decommissioning was investigated. Internal dose rates due to activity concentration of natural uranium (Unat) and 232Th in omnivorous, phytophagous, and carnivorous fish species were estimated. Radionuclide activity concentrations were obtained by spectrophotometry with arsenazo III in the visible range. The dose rate contribution of 232Th was lower than that of Unat. There were no differences between the internal dose rates to studied fish species due to 232Th, but there were differences for Unat. A dose rate of 2.30·10-2 µGy∙d-1 was found due to the two studied radionuclides. Although this value falls below the benchmark for harmful effects, it is important to acknowledge that the assessment did not account for other critical radionuclides from uranium mining, which also contribute to the internal dose. Moreover, the study did not assess external doses. As a result, the possibility cannot be excluded that dose rates at the study area overcome the established benchmarks for harmful effects.

Research on leaching behavior of uranium from a uranium tailing and its adsorption behavior in geotechnical media.

The release of uranium from uranium tailings into the aqueous environment is a complex process controlled by a series of interacting geochemical reactions. In this paper, uranium tailings from a uranium tailings pond in southern China were collected at different depths by means of borehole sampling and mixed to analyze the fugacity state of U. Static leaching experiments of U at different pH, oxidant concentration and solid-to-liquid ratios and dynamic leaching experiments of U at different pH were carried out, and the adsorption and desorption behaviour of U in five representative stratigraphic media were investigated. The results show that U is mainly present in the residue state in uranium tailings, that U release is strong in the lower pH range, that the leached U is mainly in the form of U(VI), mainly from the water-soluble, Fe/Mn oxides and exchangeable fraction of uranium tailings, and that the reduction in U leaching at higher pH is mainly due to the combined effect of precipitation formation and larger particle size of platelets in uranium tailings. Experiments with different oxidant concentrations and solid-liquid ratios showed that the oxygen-enriched state and low solid-liquid ratios were favorable for the leaching of U from uranium tailings. Adsorption and desorption experiments show that U is weakly adsorbed in representative strata, reversibly adsorbed, and that U is highly migratory in groundwater. The present research results have important guiding significance for the management of existing uranium tailings ponds and the control of U migration in groundwater, which is conducive to ensuring the long-term safety, stability and sustainability of uranium mining sites.

Assessment of internal radiation exposure caused by radon in commercially bottled spring waters consumed in Turkey.

The variation of dissolved radon levels in water supplies remains of interest since radon ingested through drinking water can give considerable radiation to the lining of the stomach. This study aims to determine the radon concentration levels in bottled spring drinking water (BSW) brands commercially sold in Turkey using a radon gas monitor and to assess the internal radiation exposure caused by the ingestion and inhalation of radon. The activity concentrations of radon analyzed in 77 BSW brands varied from 7.1±0.8 to 28.7±2.7 mBq/L with an average of 15.7±5.1 mBq/L. The total annual effective dose was estimated to assess the radiological risk for three age groups in four different scenarios based on annual drinking water intake. All estimated dose values are well below the recommended reference dose of 100 µSv for drinking water. Therefore, radon gas in the investigated BSW samples poses no significant radiological risk to the public.

Reconstruction of the Sources and Their Contributions to 129I in Northern Xinjiang, China.

Anthropogenic 129I, as a long-lived fission product and volatile radionuclide, can be used to investigate dispersion of air masses and the deposition of atmospheric pollution. Surface soil and soil core samples were collected from Northern Xinjiang and analyzed for 127I and 129I. The results show that 129I/127I atomic ratios in surface soil are inhomogeneous with a range of (2.07-106) × 10-9, and the maximum values in each soil core occurred at surface-subsurface layers (0-15 cm) at undisturbed sites. The dominant source of 129I in Northern Xinjiang is European nuclear fuel reprocessing plant (NFRP) releases, accounting for at least 70% of the total inventory; less than 20% of 129I originates from the global fallout of atmospheric nuclear weapons tests; less than 10% comes from the regional deposition of nuclear weapons tests at the Semipalatinsk site; and the regional deposition from the nuclear weapons tests at the Lop Nor site is insignificant. The European NFRP-derived 129I was transported to Northern Xinjiang via long-distance atmospheric dispersion with the westerlies through Northern Eurasia. The distribution of 129I in the surface soil in Northern Xinjiang is mainly controlled by topography, wind fields, land utilization, and vegetation coverage.

Nitrate-Stimulated Release of Naturally Occurring Sedimentary Uranium.

Groundwater uranium (U) concentrations have been measured above the U.S. EPA maximum contaminant level (30 µg/L) in many U.S. aquifers, including in areas not associated with anthropogenic contamination by milling or mining. In addition to carbonate, nitrate has been correlated to uranium groundwater concentrations in two major U.S. aquifers. However, to date, direct evidence that nitrate mobilizes naturally occurring U from aquifer sediments has not been presented. Here, we demonstrate that the influx of high-nitrate porewater through High Plains alluvial aquifer silt sediments bearing naturally occurring U(IV) can stimulate a nitrate-reducing microbial community capable of catalyzing the oxidation and mobilization of U into the porewater. Microbial reduction of nitrate yielded nitrite, a reactive intermediate, which was further demonstrated to abiotically mobilize U from the reduced alluvial aquifer sediments. These results indicate that microbial activity, specifically nitrate reduction to nitrite, is one mechanism driving U mobilization from aquifer sediments in addition to previously described bicarbonate-driven desorption from mineral surfaces, such as Fe(III) oxides.

Plutonium Signatures in a Dated Sediment Core as a Tool to Reveal Nuclear Sources in the Baltic Sea.

Plutonium distribution was studied in an undisturbed sediment core sampled from the Tvären bay in the vicinity of the Studsvik nuclear facility in Sweden. The complete analysis, including minor isotopes, of the Pu isotope composition (238Pu, 239Pu, 240Pu, 241Pu, 242Pu, and 244Pu) allowed us to establish the Pu origin in this area of the Baltic Sea and to reconstruct the Studsvik aquatic release history. The results show highly enriched 239Pu, probably originating from the Swedish nuclear program in the 1960s and 1970s and the handling of high burn-up nuclear fuel in the later years. In addition, the 244Pu/239Pu atomic ratio for the global fallout period between 1958 and 1965 is suggested to be (7.94 ± 0.31)·10-5. In the bottom layer of the sediment, dated 1953-1957, we detected a higher average 244Pu/239Pu ratio of (1.51 ± 0.11)·10-4, indicating the possible impact of the first US thermonuclear tests (1952-1958).

An overview of plutonium isotopes in soils, China: Distribution, spatial patterns, and sources.

Plutonium (Pu) is an anthropogenic radionuclide which has drawn significant attentions due to its radiotoxicity, and the sources of plutonium linked with nuclear accidents and contaminations. The 240Pu/239Pu atom ratio is source dependent and can be used as a fingerprint to determine the sources of radioactive contaminant. However, the distribution and sources of plutonium in soils of China have not yet been systematically studied at a national scale up to date. The distribution, spatial patterns, and sources of plutonium in soils of China were discussed in this work. The concentrations of 239,240Pu are in the range of 0.002-4.824 mBq/g with a large variation, and the 239,240Pu concentrations in surface soils increase with the increasing latitude, which affects by multi-factors such as organic matter and particle size, etc. The inventories of 239,240Pu are in the range of 7.31-554 Bq/m2. The weighted average of 240Pu/239Pu atom ratios (0.180 ± 0.004) in all surface samples is good agreement with the ratio of global fallout (0.180 ± 0.014) of the nuclear weapons tests, this indicate that the major source of plutonium in China is global fallout. However, among some sites, distinctly lower 240Pu/239Pu atom ratio compared to the global fallout values were observed in the northwest China, indicating a significant contribution from other source besides the global fallout. Furthermore, the spatial clustering patterns of hot spots (high values) and cold spots (low values) for plutonium showing the clear associations with nuclear tests, especially the Chinese Lop Nor nuclear weapons tests (CNTs) and the Semipalatinsk nuclear weapons tests (STS). Radioactive material including plutonium from the STS or CNTs was transported by the prevailing westerlies to the northwest China. This review about the fingerprints and distribution of plutonium in soils of China will help researchers to establish a reference database for future radiation risk assessment and environmental radioactive management.

Radiation dose and lifetime risk for radiation-induced cancer due to natural radioactivity in tap water from Jordan.

The purpose of this study was to investigate the radiological quality of drinking water in Ma'an governorate, which includes the archeological city of Petra and is one of Jordan's most important tourist destinations. To the best of the authors' knowledge, this is the first study in southern Jordan that investigates radioactivity in drinking water and its potential to cause cancer. A liquid scintillation detector was used to measure gross alpha and gross beta activities in tap water samples from Ma'an governorate. A high-purity Germanium detector was used to measure the activity concentrations of 226Ra and 228Ra. Gross alpha, gross beta, 226Ra, and 228Ra activities were < 110-724 mBq/l, < 220-362 mBq/l, < 11-241 mBq/l, and < 32-49 mBq/l, respectively. The results were compared to internationally recommended levels and literature values. Annual effective doses ([Formula: see text]) from 226 and 228Ra intake were calculated for infants, children, and adults. The highest doses were found for children while the lowest were found for infants. For each water sample, the lifetime risk of radiation-induced cancer (LTR) was calculated for the whole population. All of the LTR values were lower than the value recommended by the World Heath Organisation. It is concluded that there are no significant radiation-related health risks associated with consumption of tap water from the studied region.

Effect of radioactive cesium-rich microparticles on radioactive cesium concentration and distribution coefficient in rivers flowing through the watersheds with different contaminated condition in Fukushima.

Radioactive cesium-rich microparticles (CsMPs) derived from the Fukushima Daiichi Nnuclear Power Plant accident were detected from soils and river water around Fukushima Prefecture, Japan. Because CsMPs are insoluble and rich in radioactive cesium (RCs), they may cause the overestimation of solid-water distribution coefficient (Kd) for RCs in the water. Previous studies showed the proportion of RCs derived from CsMPs on RCs concentration in soils collected from areas with different contaminated levels. Because the proportion of RCs concentration derived CsMPs to the RCs concentration of soils in the less contaminated areas is higher than that in the highly contaminated areas, the effect of CsMPs on particulate RCs concentration in river water may be larger in the less contaminated areas. However, the difference in the effects of CsMPs on the particulate RCs concentration and Kd in river water flowing through watersheds with different contaminated levels has not been clarified. In this study, we investigated the effect of CsMPs on the particulate RCs concentration and Kd in two rivers, Takase River and Kami-Oguni River, flowing through the watersheds with different RCs contaminated levels in Fukushima Prefecture. CsMPs might enter rivers due to soil erosion because they were detected only in some samples collected from both rivers during flood events. CsMPs accounted for more than half of particulate RCs concentration in some water samples collected in the flood condition. In particular, the proportion of CsMPs in particulate RCs for the Kami-Oguni River was greater than that for the Takase River. However, when evaluating for the entire water sampling in the flood condition, a proportion of RCs concentration derived from CsMPs in the average RCs concentrations per unit mass of SS in both river waters collected in the flood condition was not large. CsMPs might temporarily increase the particulate RCs concentration and Kd in the flood event, but CsMPs did not significantly affect them when evaluated throughout the event.

Impact of the Fukushima Accident on 3H and 14C Environmental Levels: A Review of Ten Years of Investigation.

The investigation of the impact of the Fukushima accident is still going on although more than ten years have passed since the disaster. The main goal of this paper was to summarize the results of tritium and radiocarbon determinations in different environmental samples, possibly connected with the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. A document containing compiled data may serve as a solid basis for further research in the selected fields. To accomplish such effort, we went through dozens of relevant published papers, reporting 3H and 14C activity concentrations in precipitations, groundwater, seawater, river systems, tree rings, and, in some more extraordinary samples, such as herbaceous plants or debris from the damaged reactor buildings. As the referenced results would not be obtainable without adequate analytical techniques, the most common methods for routine measurement of tritium and radiocarbon concentrations are discussed as well. We believe that the correct identification of the affected environmental compartments could help quantify the released 3H and 14C activities and track their following fate, which could be especially important for plans to discharge contaminated water from the FDNPP in the upcoming years.

A comprehensive study of radon in drinking waters of Hanumangarh district and the assessment of resulting dose to local population.

Study of radon concentration in drinking water from different sources (groundwater and surface water) used across the Hanumangarh district of Rajasthan, India, was done using scintillation-based detector. The concentration of radon in surface water varied from 0.12 to 2.07 Bq/l with an average value of 0.62 Bq/l and a standard deviation of 0.55 Bq/l and in groundwater samples varied from 1.61 to 8.73 Bq/l with an average value of 4.8 Bq/l and a standard deviation of 2.24 Bq/l. The ingestion and inhalation dose were calculated to assess the health risk for infants, children and adults. The resulting average annual effective dose has been found to be considerably lower than the recommended safe limit of 0.1 msv/y (WHO, In: Incorporating first and second addenda, third ed. WHO Press, Geneva. 3rd ed. World Health Organisation, Geneva, Switzerland, 2008). It can be concluded that radon in water does not pose a significant radiological health risk to the population of the studied area.

222Rn and 226Ra concentrations in selected shallow circulation groundwaters from the Fore-Sudetic Monocline area.

Natural radioactive isotopes occur in various components of the natural environment, including groundwater. The general population, not always aware of possible threats, can use its resources. The activity concentration of some of the radioactive isotopes should be monitored, especially in those intakes from which it is possible to obtain water for human consumption, e.g. in domestic wells. The conducted research was innovative due to the fact that in many countries, including Poland, there are no regulations on waters exploited from home wells using as a drinking water source. As the groundwaters from this area have not been examined for radon (222Rn) and radium (226Ra) occurrence yet, the goal of this research was to perform screening tests in this part of the Fore-Sudetic Monocline. For this purpose, the authors have measured the concentration of 222Rn and 226Ra activity in groundwater collected from this geological unit located in south-western Poland. 222Rn and 226Ra occurrence was researched, and specific electrolytic conductivity, redox potential, pH and temperature were measured in 52 groundwater samples. 222Rn activity concentration ranged from 0.18 to 19.78 Bq/dm3. Only in three cases, 226Ra activity concentration reached a value above the lower detection limit of the applied method, i.e. 0.05 Bq/dm3 (max. 0.77 Bq/dm3). The authors present completely new data on the occurrence of these radioactive isotopes in the waters of the first aquifer in the Fore-Sudetic Monocline, which is not without significance for the health of consumers of these waters.

Elevated radon level in drinking water of Ajodhya Hill Area of West Bengal, India: probable health impact on lung and stomach.

A screening survey has been carried out to measure the radon concentration in drinking water at various locations of Ajodhya hill and surrounding areas in Purulia district of West Bengal, India, using AlphaGUARD radon monitor. The obtained 222Rn concentration in ground water varies from 5.71 ± 0.29 to 579.47 ± 23.18 Bq/l with an average of 110.00 ± 6.61 Bq/l. Comparison between our results with the internationally recommended reference levels reveals that drinking of water from the majority of these tube-wells can pose significant health risks to the local people. Correlation study indicates that tube-well depth has significant influence on the radon level in water samples. Using 60 l/yr and 1642.50 l/yr water consumption estimated annual effective radon doses for most of the samples (almost 70% and 96%, respectively) are high compared to the World Health Organization (WHO) and the European Union (EU) Commission prescribed reference dose limit of 100 µSv/yr. Also, the evaluated Excess Lifetime Cancer Risk (ELCR) values associated with the tube-wells are showing serious threat to the health of the locals.The primary goal of this work is to develop a radon profile map of this area and to find out the possible reasons behind the elevated radon level in ground water. This type of work may play a very crucial role to aware the locals in perspective of human exposure to radon. The local health officials and the water quality regulators of India are requested to take necessary steps for protecting the local people from water radon hazard.