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Radioactivity levels of 210Pb and 226Ra were detected in a sediment core obtained using a multi-corer from the polymetallic nodule area inside the Clarion-Clipperton Zone (CCZ), a contract area of the China Ocean Mineral Resources Association (COMR) in the eastern Pacific Ocean. The profile of excess 210Pb (210Pbex) shows that the specific activity of 210Pbex has three parts with different distributions at depths of 0–16 cm (I), 17–36 cm (II), and 37–48 cm (III). When the I section of nonlocal mixing was excluded, using a steady-state diffusion mode, the bioturbation coefficients of the core were estimated to be 24.2 cm2/a at 17–36 cm deep and 5.9 cm2/a at 37–48 cm deep, which were greater compared to previously published results. This is most likely owing to bioturbations caused by various organism species in the two sections. [ABSTRACT FROM AUTHOR]

The activity concentrations of natural radionuclides from 80 samples of Malaysia's building materials sourced from either manufacturers or local suppliers were studied using high-purity germanium (HPGe) detector. The radiological hazards associated with building materials under study were evaluated by calculating radium equivalent activity (Raeq). The calculated values of Raeq range from 29.7 ± 0.9 to 564.8 ± 13.6 Bq kg−1 with an overall average value of 198.1 ± 98.5 Bq kg−1. The calculated activity concentrations of 226Ra, 232Th and 40 K were further subjected to RESRAD-BUILD computer code with a view to determine long-term indoor external and internal doses received by a dweller from zero to 70 years. A significant variation in the indoor doses from zero to 30 years was observed while a relatively constant behaviour was observed from 30 to 70 years. The assessment of the indoor doses also showed that the indoor doses from walls are significantly high compared with indoor doses from the room floor. The calculated Raeq and long-term projection of indoor doses received by the dweller was below the recommended maximum values of 370 Bq kg−1 and 1000 µSv y−1, respectively. Therefore, the potential radiological hazards associated with building materials under study are negligible. [ABSTRACT FROM AUTHOR]

Retreatment of recurrent or second primary head and neck cancers occurring in a previously irradiated field is complex. Few guidelines exist to support practice. We performed an updated literature search of peer-reviewed journals in a systematic fashion. Search terms, key questions, and associated clinical case variants were formed by panel consensus. The literature search informed the committee during a blinded vote on the appropriateness of treatment options via the modified Delphi method. The final number of citations retained for review was 274. These informed 5 key questions, which focused on patient selection, adjuvant reirradiation, definitive reirradiation, stereotactic body radiation, and reirradiation to treat nonsquamous cancer. Results of the consensus voting are presented along with discussion of the most current evidence. This provides updated evidence-based recommendations and guidelines for the retreatment of recurrent or second primary cancer of the head and neck. [ABSTRACT FROM AUTHOR]

The extraction of 224Ra and 228Ac with dibenzo-21-crown-7 resin was studied in solutions with Rose Bengal and identical solutions without Rose Bengal (blanks) from pH 3 to 12. Batch studies demonstrated that actinium is extracted at high pH (> 10) from both solutions but with a significantly higher extraction from the Rose Bengal solutions (maximum extraction ~ 60,000) than the blank solutions (maximum extraction ~ 2,000). In the Rose Bengal solutions, there was a weak extraction of actinium at lower pH (4–10) as well. There was no uptake of radium from the blank solutions, and a weak extraction at all pH levels from the Rose Bengal solutions. Kinetics studies were performed for actinium only, as radium had no significant extraction. Two column studies are demonstrated for the separation of radium from actinium. These separations are moderately effective with ~ 78% of the actinium recovered with no detectable radium. [ABSTRACT FROM AUTHOR]

Kütahya is one of the provinces with many well-known spas in Turkey. Radionuclide levels in the thermal waters of these spas have not been measured before. Therefore, the radon and radium concentrations in thermal waters collected from Kütahya spas were measured using the collector chamber method. In addition, the indoor radon concentrations of spas were determined using LR-115 type II solid-state nuclear track detectors. The annual effective doses from the inhalation and ingestion of radon and radium concentrations have been calculated. The sampling points' physical and chemical properties were also measured during the survey. [ABSTRACT FROM AUTHOR]

Over the last decade, there has been a rapid growth in the use of hydraulic fracturing (fracking) to recover unconventional oil and gas in the Permian Basin of southeastern New Mexico (NM) and western Texas. Fracking generates enormous quantities of wastes that contain technologically enhanced naturally occurring radioactive materials (TENORM), which poses risks to human health and the environment because of the relatively high doses of radioactivity. However, very little is known about the chemical composition and radioactivity levels of Permian Basin fracking wastes. Here, we report chemical as well as radiochemical compositions of hydraulic fracking wastes from the Permian Basin. Radium, the major TENORM of interest in unconventional drilling wastes, varied from 19.1 ± 1.2 to 35.9 ± 3.2 Bq/L for 226Ra, 10.3 ± 0.5 to 21.5 ± 1.2 Bq/L for 228Ra, and 2.0 ± 0.05 to 3.7 ± 0.07 Bq/L for 224Ra. In addition to elevated concentrations of radium, these wastewaters also contain elevated concentrations of dissolved salts and divalent cations such as Na+ (31,856–43,000 mg/L), Ca2+ (668–4123 mg/L), Mg2+ (202–2430 mg/L), K+ (148–780 mg/L), Sr2+ (101–260 mg/L), Cl− (5160–66,700 mg/L), SO42− (291–1980 mg/L), Br− (315–596 mg/L), SiO2 (20–32 mg/L), and high total dissolved solid (TDS) of 5000–173,000 mg/L compared to background waters. These elevated levels are of radiological significance and represent a major source of Ra in the environment. The recent discovery of large deposits of recoverable oil and gas in the Permian Basin will lead to more fracking, TENORM generation, and radium releases to the environment. This paper evaluates the potential radiation risks associated with TENORM wastes generated by the oil and gas recovery industry in the Permian Basin. [ABSTRACT FROM AUTHOR]

The specific activity of terrestrial potassium, thorium, and radium as well as radiocesium isotopes in Sarajevo city was determined. From the measured γ-ray spectra, the activity concentrations were determined for 40K, 232Th, 226Ra, and 137Cs with the respective average values of 460, 39, 32, and 52 Bq kg–1. The corresponding annual effective dose indoor and outdoor values were within the maximum limit of 1 mSv year–1 given by UNSCEAR. The calculated adsorbed dose rate in air was 0.058 μGy h–1. In general, all hazard index parameters were within the criterion upper limits, implying insignificant radiation risk hazard. [ABSTRACT FROM AUTHOR]

Over the past ∼15 y, unconventional oil and gas (UOG) production utilizing hydraulic fracturing and horizontal drilling has increased dramatically in the Marcellus Shale in the Appalachian region of the USA. The area also has a long history of conventional oil and gas (COG) production as well as coal mining, and the 3 extractive activities (UOG, COG, and coal mining) often occur in the same watersheds. Produced water and wastewater from oil and gas (OG) extraction can have very high concentrations of dissolved metals, radionuclides, and other solutes. Previous studies have documented streamwater pollution associated with spills and releases of these fluids, but it remains unclear whether OG development has broad regional effects on streamwater quality. This study assessed whether COG and UOG well densities in watersheds were associated with water-quality metrics, including specific conductance, dissolved metals, nutrients, radium isotopes, and anions, when controlling for coal mining and land cover. Water quality was measured at 120 stream sites with non-nested watersheds in the Marcellus Shale region. Linear modeling revealed that COG well density was associated with higher concentrations of Mg and Cl−, and UOG well density was associated with higher 228Ra:224Ra ratios, suggesting that this ratio might be a useful indicator of UOG development in watersheds. Adding OG well density to linear models explaining the concentrations of water-quality variables improved R 2 by ≤0.04, indicating little increase in explanatory power. However, linear regression coefficients indicated that an increase in COG well density from 0 to 11 wells/km2 (the maximum well density observed in our study area) could be associated with 35× increases in Mg and Cl− concentrations, although the SE of these estimates was large. This research suggests that OG well density may have small but measurable effects on streamwater quality; however, the effects of other human activities and land uses, such as coal extraction and urban development, are likely larger and more environmentally relevant. [ABSTRACT FROM AUTHOR]

Two ICP-MS methods were developed to measure the radiotoxic isotope 226Ra in brain tissues from a radium dial painter worker. The first method was a direct analysis of acid digested samples using quadrupole ICP-MS. The instrumental LOD of 226Ra was 0.1 ng kg−1. Polyatomic interferences at m/z 226 were investigated and Pb was identified from a polyatomic interferent in an in-house sample prepared from bovine brain, with a 226/208 formation ratio of 4 × 10−8. The quadrupole ICP-MS method was also used to measure levels of beryllium, strontium, and uranium. A second method was developed that included cation-exchange chromatography to separate 226Ra followed by analysis with sector field MC-ICP-MS. The instrumental LOD for the cation exchange method with MC-ICP-MS detection was 0.5 pg kg−1 (19 mBq kg−1). The measured concentrations of 226Ra in different brain regions ranged from 0.09–0.72 ng kg−1 (3.3–27 Bq kg−1) and radium was non-uniformly distributed in the brain. [ABSTRACT FROM AUTHOR]

Radium has been commonly used as a tracer of submarine groundwater discharge to the ocean and embankments, as radium activities are commonly input into box models to calculate a groundwater flux. Similarly, isotopes of radium (Ra224, Ra223, Ra226, Ra228) have been used to calculate water mass ages, which have been used as a proxy for residence times. Less commonly, radium and other tracers have been utilized in mixing models to determine the relative contribution of groundwater to a marine system. In the literature, all of these methods have almost exclusively been solved using analytical methods prone to large errors and other issues. Project Open RaDOM, introduced here, is a collection of open-source R scripts that numerically solve for groundwater flux, residence time, and relative contribution of groundwater to coastal systems. Solving these models numerically allows for over-constrained systems to increase their accuracy and force real solutions. The scripts are written in a way to make them user-friendly, even to scientists unfamiliar with R. This communication includes a description of the scripts in Project Open RaDOM, a discussion of examples in the literature, and case studies of the scripts using previously published data. [ABSTRACT FROM AUTHOR]

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Available literature data on the aqueous chemistry of radium are compiled. There are limited available experimental data and a significant portion of the data has been estimated using electrostatic techniques, typically based on the corresponding data of barium. The available data are compared with the corresponding data of barium (and strontium) and a methodology for estimating additional radium thermochemical data is described. [ABSTRACT FROM AUTHOR]

This research paper is devoted to measure the activity contents of natural radionuclide, like, radium (226Ra), thorium (232Th) and potassium (40K) in the soil gathered along the Jwalamukhi thrust of Himachal Pradesh, North Western Himalayas, India. NaI(Tl) Scintillator detector was utilized for the estimation of activity content. The activity concentration of 226Ra, 232Th and 40K for some of the soil samples have been observed to be above the global normal mean values. The outcomes acquired for indoor and outdoor effective dosage are well below the normal international and national proposed results. The determined values of external hazard (Hex) for studied locations are less than unity, therefore; samples assembled from these regions are safe from a health hazard point of view and can be utilized as a construction purposes without producing any radio-logical hazard to human beings. The average estimations of radium equivalent activity were found to be within the limits suggested by Organization for Economic Cooperation and Development (OECD). Radon (222Rn) and thoron (220Rn) exhalation rates have also been calculated and discussed. [ABSTRACT FROM AUTHOR]

Safety assessments for deep geological repositories involve risk calculations for the release of radionuclides like Ra, U, Pu and trivalent actinides from the storage containers to the groundwater. The retention of radionuclides through water-mineral interaction along the groundwater flow path could be a crucial factor in case of a repository failure. Barite (BaSO 4) assumes significance in this context, as it has the potential to (re)crystallize and incorporate significant quantities of radioactive elements under relevant physico-chemical conditions. The assessment of mineral-fluid partition coefficients provides a means to evaluate the uptake potential of elements into the mineral. Usually, partition coefficients are determined under well-defined and controlled experimental conditions in laboratories. However, these results have shown discrepancies to partitioning coefficients determined from natural systems. Furthermore, effects like diagenesis or changes in the chemical fluid parameters might lead to a secondary alteration of the phases and affecting the retention ability. Here we investigate the incorporation of trace elements in natural barite from a borehole at 415 m depth in the Äspö Hard Rock Laboratory (Sweden). High-resolution LA-ICP-MS enables the quantitative determination of field-based partition coefficients through the integrated pixel average of selected zones in element distribution maps, combined with existing fluid concentration data. Similarities between the solid solution systems (Ra,Ba)SO 4 and (Sr,Ba)SO 4 allowed the combination of Sr partitioning data with density-functional theory simulations for an estimation of the partition coefficient value for Ra in natural barite. Values in the 10−2 range were determined, showing a deviation from those reported in previous experimental studies in the 10° range. Moreover, lanthanum serves as an analogue element for the radioactive trivalent actinides. The partition coefficient values for La in natural barite were determined in the range of 10−2 and 10−1, aligning well with experimental partition coefficients. Although density functional theory simulations cannot directly convert a La partition coefficient into a partition coefficient for trivalent actinides, it is assumed that these elements exhibit comparable behavior. Besides primary growth zonation, La also exhibits strong secondary enrichment, probably resulting from groundwater mixing and late fluid-mediated element transport through connected intracrystalline pore space oriented at cleavage plane systems. Additional SIMS analysis provides insights into the temporal variation of the sulfate source at the sampling site reflecting the influence of different waters during mineral growth. This study demonstrates a discrepancy between natural and synthetic P Ra for barite and emphasizes that secondary processes significantly impact radionuclide retention in barite. Including these effects in reactive transport models will improve the reliability and applicability of integrative risk models. • Barite Ra partitioning estimation using DFT simulations with natural analogue Sr. • LA-ICP-MS maps imply high La and potentially An3+ conc. along barite cleavage planes. • Natural barite samples reach lower Ra partitioning values than laboratory experiments. [ABSTRACT FROM AUTHOR]

This work presents comprehensive results of alpha (210Po, 228,230,232Th) and gamma (40K, 226,228Ra, 137Cs) radioactivity measurements in selected food typically consumed by infants (< 1 year) in Croatia. The samples of readily available infant's food on Croatian market were categorized according to the growth of an infant, from their first nourishment: adapted powdered milk, to their first solid food. The aim was to estimate ingestion doses and the potential radiological risks for infants. In addition to anthropogenic radionuclides, the study focused on naturally occurring radionuclides often underrepresented in similar researches. 40K prevails in activity concentrations in all types of samples. 210Po was determined in all sample types reaching up to 502 mBq/kg. Maximum values of activity concentrations for 228Ra, 226Ra and Th isotopes were 230 mBq/kg, 1.29 Bq/kg and 52 mBq/kg, respectively. The most important contributors to the annual effective dose were 40K, 226Ra, 210Po and 228Ra contributing with 29 % 28 %, 24 % and 17 %, respectively. Th isotopes contributed with less than 2 %, while the contribution of anthropogenic radionuclides 137Cs and 90Sr were negligible (less than 1 %). Cumulative effective ingestion dose for infants was calculated to be 0.69 mSv/y, which is below the recommended limiting dose of 1 mSv/y. Largest proportion comes from the intake of fruit (33 %), followed by the intake of vegetables 19 %) and cereals 19 %). Although national radioactivity monitoring programs usually focus on anthropogenic radionuclides, this study highlights that naturally occurring radionuclides are dominant contributors to the cumulative effective ingestion dose in infants. Overall, the estimated cumulative effective ingestion dose for infants from consuming food available in Croatia is below recommended dose limits and therefore does not present a radiological concern. • Comprehensive results of αand γ radioactivity in baby food in Croatia are presented. • 210Po, Th and Ra isotopes, 40K and 137Cs are quantified in most of the samples. • The annual ingestion dose for infants is estimated to be 0.69 mSv/y. • 40K, 226Ra, 210Po and 228Ra contribute with 29 %, 28 %, 24 % and 17 % to the dose. • Highest part comes from intake of fruit (33 %), vegetables (19 %) and cereals (19 %). [ABSTRACT FROM AUTHOR]

Investigations conducted during the GEOSECS program concluded that radium-226 (T1/2 = 1602 y) and barium are tightly correlated in waters above 2500 m in the Atlantic, Pacific and Antarctic Oceans, with a fairly uniform 226Ra/Ba ratio of 2.3 ± 0.2 dpm µmol-1 (4.6 nmol 226Ra/mol Ba). Here, we report new 226Ra and Ba data obtained at three different stations in the Pacific Ocean: stations K1 and K3 in the North-West Pacific and station old Hale Aloha, off Hawaii Island. The relationship between 226Ra and Ba found at these stations is broadly consistent with that reported during the GEOSECS program. At the three investigated stations, however, we find that the 226Ra/Ba ratios are significantly lower in the upper 500 m of the water column than at greater depths, a pattern that was overlooked during the GEOSECS program, either because of the precision of the measurements or because of the relatively low sampling resolution in the upper 500 m. Although not always apparent in individual GEOSECS profiles, this trend was noted before from the non-zero intercept of the linear regression when plotting the global data set of Ba versus 226Ra seawater concentration and was attributed, at least in part, to the predominance of surface input from rivers for Ba versus bottom input from sediments for 226Ra. Similarly, low 226Ra/Ba ratios in the upper 500 m have been reported in other oceanic basins (e.g. Atlantic Ocean). Parallel to the low 226Ra/Ba ratios in seawater, higher 226Ra/Ba ratios were found in suspended particles collected in the upper 500 m. This suggests that fractionation between the two elements may contribute to the lower 226Ra/Ba ratios found in the upper 500 m, with 226Ra being preferentially removed from surface water, possibly as a result of mass fractionation during celestite formation by acantharians and/or barite precipitation, since both chemical elements have similar ionic radius and the same configuration of valence electrons. This finding has implications for dating of marine carbonates by 226Ra, which requires a constant initial 226Ra/Ba ratio incorporated in the shells and for using 226Ra as an abyssal circulation and mixing tracer.

The relevance of the research is to obtain new information on hydrogeology and hydrogeochemistry of underexplored fields Novosibirsk radon waters in the south of Western Siberia. Novosibirsk is one of those few cities in Russia that were laid on granites – a source of radon emanation (222Rn). The study area is confined to the inner area of the large Novosibirsk granitoid massif. There were no scientific generalizations of the available factual material. The aim of the research is to identify the features of the hydrogeological structure and hydrogeochemistry of the mineral hydro-radon occurrence «Kamenskoe» and to study the forms of migration of chemical elements and the saturation degree to minerals. Methods. Sampling was carried out in accordance with generally accepted methods. Compilation and analysis of hydrogeochemical data was carried out using the software Microsoft Excel, STATISTICA, SURFER, Grid Master. In the environment of Visual Minteq and WATEQ4f software packages, physicochemical calculations of the migration forms of chemical elements in radon waters and the degree of their saturation to a number of rock-forming minerals were performed. Results. In the hydrogeological section of the «Kamenskoe» hydro-radon occurrence two aquifers was established (from top to bottom): pore water of Quaternary aquifer and fissure-vein waters of Upper Paleozoic granites. In the central part of Novosibirsk, the infiltration of atmospheric precipitation is complicated, the natural regime of groundwater supply is disturbed. Pore-stratal waters of Quaternary sediments, waters of the zone of regional fracturing and fracture-vein waters of Upper Paleozoic granites are located in a common mixing area, which is influenced by flooding and anthropogenic pollution. Thus, in the water-bearing complex of the Upper Paleozoic granites, two hydrogeochemical zones are distinguished: the upper one is the waters of the regional fracturing zone in the flooding area under anthropogenic impact, and the lower one is the fractured-vein mineral radon waters. Mineral radon fissure-vein waters of granites are not subject to anthropogenic influence and are installed in well no. 4p (interval 73–74 m) and in well no. 16 at depths from 73 to 128 m. They are cold, fresh, HCO3 Na-Ca and HCO3 Na-Mg-Ca composition with TDS from 613,4 to 689,9 mg/dm3 and silicon content 10,3–13,6 mg/dm3. They are characterized by pH from neutral to slightly alkaline (6,9–7,8) and oxygen-nitrogen composition of water-dissolved gases. The established activity of 222Rn varies in the range of 1101–1570 Bq/dm3 (strongly radon waters according to the classification of N.I. Tolstikhin); content: 238U from 5,6∙10–3 to 6,5∙10–3 mg/dm3 and 226Ra from 2,7∙10–9 to 1,8∙10–8 mg/dm3. With an increase in the total mineralization of radon waters, the proportion of simple cationic forms of Mg2+, Ca2+, Na+, Sr2+, Ba2+ in solution decreases, which is associated with the formation of hardly soluble carbonate and sulfate compounds. In radon waters, Fe(II) forms are presented as Fe2+, FeHCO3+, FeCO30. Ferrum (III) migrates in the form of positively charged hydroxo complexes Fe(OH)2+ and neutral Fe(OH)30. Among the forms of manganese migration, the simple cation Mn2+ (43,71–99,99 %) dominates, the remaining forms are represented by MnHCO3+ (9,89–28,27 %) and MnCO30 (0,01–37,39), to an even lesser extent MnSO40 (0,20–2,25 %), MnCl+ (0,04–1,12 %) and MnOH+ (0,01–0,05 %). The chemical forms of migration of heavy metals (nickel and copper) are presented in the form of free cations (Ni2+, Cu2+), hydrocarbonate (NiHCO3–, CuHCO3–) and carbonate (NiCO30, CuCO30) complexes. Copper also migrates in the neutral form Cu(OH)20. Beryllium (hazard class 1) migrates in the form of the hydroxo complex Be(OH)2. The established features of the geochemical types of waters, the proportional distribution of forms and coefficients of water migration of chemical elements revealed the complication of the composition of equilibrium minerals from siderite, ferrihydrite, and greenalite in surface waters to saturation with calcite, dolomite, magnesite, rhodochrosite, and talc in fractured vein waters of the Upper Paleozoic granites. The forms of migration of chemical elements determine the mechanisms of dissolution/precipitation of mineral compounds.

The relevance of the research lies in obtaining the first isotope-geochemical data on natural waters and host rocks of the «Inskie springs» occurrence of low-radon waters. The aim of the research is to study the peculiarities of chemical composition of natural waters and water-bearing rocks and obtain the first information on the total ά- and β-activity of natural waters, the activity of 222Rn and the isotopic composition of δD, δ18O, δ13С, 234U, 238U, 226Ra and 228Ra. Methods. Sampling was carried out in accordance with generally accepted techniques. Laboratory study of the chemical composition by titrimetry, ion chromatography, inductively coupled plasma mass spectrometry was carried out at the Problem Research Laboratory of Hydrogeochemistry of the TPU School of Natural Resources. The analysis of the complex of isotopic ratios δD, δ18O, δ13СDIC of waters and dissolved inorganic carbon was carried out at the Center for Collective Use of the IGM SB RAS using the Isotope Ratio Mass Spectrometer FinniganTM MAT 253. Data on the total ά- and β-activity of natural waters, as well as the activities of 234U, 238U, 226Ra и 228Ra were obtained using gamma and alpha spectrometry (after preliminary radiochemical sample preparation). Results. In 2019, 35 km from Novosibirsk, far from the known granite massifs, the «Inskie springs» occurrence of low-radon waters was discovered, referring to the waters of the regional fracture zone. The work presents the first results of their geochemical studies. The waters are moderately fresh HCO3 Mg-Ca with a total mineralization from 389 to 536 mg/dm3 with a silicon content of 4,14–8,61 mg/dm3. They are characterized by pH from neutral to slightly alkaline (7,1 – 8,4), oxidative geochemical environment with Eh +205,3 –+231,8 mV and O2dissolved content of 6,24–12,26 mg/dm3. The activity of 222Rn varies in the range of 7–149 Bq/dm3; contents: 238U from 2,83∙10–3 to 4,13∙10–3 mg/dm3 and 232Th from 2,39∙10–6 to 1,16∙10–5 mg/dm3. According to the isotopic composition, the origin of water is infiltration. The range of δ18O values in waters varies from –17,1 to –16,7 ‰ with δD values from –128,4 to –126,2 ‰ and δ13C variation is in the range of –13,1 to –10,3 ‰. The host rocks are dark gray (to black) shales, sometimes gray, with a small admixture of silty and sandy-silty material. The isotopic composition of calcite in the host rocks is characterized by similar values: δ13C varies from –3,1 to –2,7 ‰, δ18O – from 17,2 to 18,4 ‰. Weathered clay shales are characterized by lower contents of δ13C (up to –11,0 ‰) and δ18O (up to 13,9 ‰). Also, according to the results of geochemical studies, these samples are characterized by a significant decrease in the content of all trace elements (except for U), which indicates an active interaction of waters with the host rocks.

Drinking water is essential to human life. However, it can be polluted by various factors, including radioactive substances such as radon 222 Rn and radium 226 Ra. Therefore, the determination of their concentrations is important for public health. The aim of this work is to measure the concentration of 226 Ra in samples of tap, natural spring and well water taken from different sources in the eastern region of Morocco, as well as in a few samples of bottled mineral water. We used an AlphaGUARD detector with an AlphaKit accessory and an RTM1688-2 to carry out measurements of radon in secular equilibrium with radium. The got results show that the 226 Ra activity is less than 0.104 ± 0.023 Bq/L , the Annual Effective Dose (AED)) for adults and children is less than 29.1 ± 4.7 μ Sv.y−1 and 123.8 ± 4.7 μ Sv.y−1 for infants. The chemical toxicity risk evaluated using the Lifetime Average Daily Dose (LADD) was found less than 0.23 ± 0.05 μgkg −1 day −1 . The obtained results are reasonable in relation to international guidelines, and do not present any radiological hazard to consumers that could be attributed to the radium and radon in the analyzed water samples. • Radioactive Substance Assessment: The study evaluates radon and radium concentrations in drinking water, shedding light on potential health risks. • Regional Focus - Eastern Morocco: Providing localized insights, the research emphasizes the importance of region-specific water quality assessments for public health considerations. • Precision in Measurement: Utilizing an Alpha GUARD detector with an AlphaKit accessory demonstrates the study's meticulous measurement approach, ensuring the reliability of results. • Safety Confirmation: Results indicate that 226Ra activity is below international recommendations, assuring the safety of tap, spring, and well water and confirming compliance. [ABSTRACT FROM AUTHOR]

The occurrence of enhanced concentration of the radium triplet 226Ra, 228Ra and 224Ra is a frequently observed property of highly saline anoxic deep water as used e.g. in geothermal plants. In the present study we develop a model to explain the observed activity levels in the brines. The model considers processes at the rock-fluid interface of the aquifer like alpha recoil, sorption and surface precipitation and is implemented by means of a Monte Carlo simulation. The outcomes of the simulations indicate the dominating role of fine-grained constituents of the reservoir rock, e.g. claystone with enhanced specific activities of the natural decay chains. Mass fractions of such material in the order of a few percent are sufficient to result in radium fluid concentrations >1 Bq l−1. Also a generally valid relation between the Th/U ratio in the aquifer rock and the 228Ra/226Ra activity ratio in the fluid was found. This link improves the agreement between radium fluid data and the mean Th/U ratio of the Earth's crust. The 224Ra/228Ra fluid ratios reflect the transport time from the location of last radium release to the sampling point. The model findings were applied to a well investigated aquifer used in a geothermal plant in the North German Basin. An eight component system of the aquifer rock was established as the basis for the simulation of the radium concentrations in the deep fluid. The comparison between simulation and fluid analyses revealed a degree of radium sorption of about 50 %, which is necessary to match the model's results with the measurements. On the other hand, the 228Ra/226Ra fluid ratio of the brine was well reproduced by the simulation, showing the suitability of the model even in complex heterogeneous reservoirs. From the 224Ra/228Ra fluid ratios a transition from pore-to fracture-guided transport < 10 m distance from the production well is suggested. Precipitates from such deep fluids occurring after changes of the thermodynamic conditions are able to accumulate radium isotopes in Ba/Sr-sulphate phases. The time dependence of the radioactive disequilibrium between 226Ra, 228Ra and its child 228Th in such scales is described by a mathematical model and is applied to two different uptake models. Based on this approach, age determinations on precipitates found in different components of a geothermal plant are conducted. They reveal the triggering of scale formation due to modifications in the plant. The results are suitable for drawing conclusions about the operation of the system, which result in a reduction in the amount of scale and a reduction in downtimes. • Radium concentrations in saline deep waters are caused by a balance between alpha recoils, sorption and radioactive decay. • Fluid 228Ra/226Ra ratios reflect the Th/U ratios of the aquifer rock. • Scales can be dated by combining their 228Ra/226Ra and 228Th/228Ra ratios. [ABSTRACT FROM AUTHOR]

The clinical success of [223Ra]RaCl 2 (Xofigo®) for the palliative treatment of bone metastases in patients with prostate cancer has highlighted the therapeutic potential of α-particle emission. Expanding the applicability of radium-223 in Targeted Alpha Therapy of non-osseous tumors is followed up with significant interest, as it holds the potential to unveil novel treatment options in the comprehensive management of cancer. Moreover, the use of barium radionuclides, like barium-131 and -135m, is still unfamiliar in nuclear medicine applications, although they can be considered as radium-223 surrogates for imaging purposes. Enabling these applications requires the establishment of chelators able to form stable complexes with radium and barium radionuclides. Until now, only a limited number of ligands have been suggested and these molecules have been primarily inspired by existing structures known for their ability to complex large metal cations. However, a systematic inspection of chelators specifically tailored to Ra2+ and Ba2+ has yet to be conducted. This work delves into a comprehensive investigation of a series of small organic ligands, aiming to unveil the coordination preferences of both radium-223 and barium-131/135m. Electronic binding energies of both metal cations to each ligand were theoretically computed via Density Functional Theory calculations (COSMO-ZORA-PBE-D3/TZ2P), while thermodynamic stability constants were experimentally determined for Ba2+-ligand complexes by potentiometry, NMR and UV–Vis spectroscopies. The outcomes revealed malonate, 2-hydroxypyridine 1-oxide and picolinate as the most favorable building blocks to design multidentate chelators. These findings serve as foundation guidelines, propelling the development of cutting-edge radium-223- and barium-131/135m-based radiopharmaceuticals for Targeted Alpha Therapy and theranostics of cancer. This work explores several ligands, both in silico and experimentally, highlighting which donor groups or atoms show the strongest binding affinity to Ra2+ and Ba2+. The aim is to provide the best building blocks for the rational design of tailored chelators for 223Ra/131/135mBa theranostic pair. [Display omitted] • Affinity of many mono and bidentate ligands shows the same trend for Ra2+ and Ba2+. • Ra2+ and Ba2+ prefer negatively charged and hard-donor coordinating groups. • Oxygen donors provide the strongest interactions and complexes with Ra2+ and Ba2+. • HOPOs, malonate and picolinate are suitable moieties for crafting Ba/Ra chelators. • This work will guide the rational design of chelators tailored to 223Ra/131/135mBa. [ABSTRACT FROM AUTHOR]

• Granite and basalt meals are used as fertilizers due to their mineral composition. • Unfortunately, they are rich in radionuclides which may pose radioactive hazard. • Granite meals have higher content of 40K, 226Ra and 232Th than basalt meals. • Radioactive hazard indices exceed the permissible values in case of granite meals. • The results indicate that the use of basalt meal does not pose a radiological risk. Granite and basalt meals (rock meals) are regarded as micronutrient fertilizers due to their rich content of macro- and microelements essential for proper development of planta. However, they also are rich in radionuclides which may pose a radioactive hazard to environment, food and people. The aim of this study was to assess the environmental and human exposure to ionizing radiation emitted by natural radioactive isotopes containing in granite and basalt meals increasingly used for soil fertilization. Gamma ray spectrometry was applied in order to determine concertation of radioactive isotopes: 40K, 226Ra and 232Th. Afterwards, radiological hazard parameters were calculated in order to assess health and environmental risks. The obtained results indicated that the average radioactivity concentration of 226Ra, 232Th and 40K of all granite meal samples were higher than their average content in the Earth's crust. Whereas, basalt meals contained much lower natural radioactive isotopes. Similarly, the radiological hazard indices were higher and exceeded limit values in case of granite meals, thus excluding them from use in fertilization. Basalt meals were characterized by lower values of these indices, suggesting the possibility of their safe use in agriculture as soil fertilizers. [ABSTRACT FROM AUTHOR]

At CERN-ISOLDE, high-purity radioactive ion beams of 219Fr and 221RaF were investigated with α -decay spectroscopy at the CRIS and ASET experiments in the course of three different experimental campaigns. The half-life of 215At, α -decay daughter of 219Fr, is measured to be 36.3(3)[9] μ s , and that of 221Ra was determined to be 26.2(1)[6] s, both of which are well in line with the trends in this region of the nuclear landscape but at odds with some of the reported literature. [ABSTRACT FROM AUTHOR]

Radium (Ra) is a geogenic contaminant that occurs at high levels in the Midwestern Cambrian‐Ordovician aquifer system (MCOAS), a regionally important sandstone and carbonate drinking water aquifer. Water utilities using the MCOAS often must adopt treatment methods or use alternative water sources to maintain high‐quality drinking water. Here, we show that Ra in water obtained from a municipal well in Wisconsin remains consistent despite variation in pumping conditions. However, widely used analytical methods (e.g., scintillation counting) for measuring Ra are less precise for quantifying Ra variability given the site conditions. Although not currently used for EPA compliance, mass spectrometry improves the precision of Ra measurements by an order of magnitude over the currently used counting method (e.g., 95 ± 3 mBq/L vs. 110 ± 30 mBq/L) at the concentrations observed in this study. The use of more precise analytical methods will increase understanding of trends in Ra levels important for operating public water systems. [ABSTRACT FROM AUTHOR]

The specific activities of 226Ra, 232Th and 40K of seven different color classification of nephrite samples from Xinjiang of China were measured by gamma spectrometry, and their radiological hazard indices such as radium equivalent (Raeq), external hazard index (Hex), internal hazard index (Hin), alpha index (Iα), absorbed dose rate (D) and annual effective dose rate (AED) were investigated and assessed. According to the experimental results, the specific activity level of 226Ra, 232Th, 40K in all nephrite samples was between 13.56 and 116.39 Bq·kg−1 with an average of 44.72 Bq·kg−1, between 2.19 and 10.89 Bq·kg−1 with an average of 4.90 Bq·kg−1, and between 21.06 and 94.32 Bq·kg−1 with an average of 52.24 Bq·kg−1, respectively. The mean values of radiological indicators, such as Raeq, Hex, Hin, Iα and AED were 55.75 Bq·kg−1, 0.15, 0.27, 0.22, 0.16 mSv·y-1 (worn) and 0.13 mSv·y−1 (indoor), respectively, are lower than the international recommended value. The values of D range from 10.13 to 54.46 nGy·h−1 with an average of 25.80 nGy·h−1. In the end, it can be concluded that the use of the seven different color categories of nephrites as ornament is considered to be safe and unlikely to cause any significant biological radiation hazard to the public. [ABSTRACT FROM AUTHOR]

• Postoperative management of lower grade gliomas (grade 2 and 3) is heterogeneous. • The ARS brain panel systematically reviewed the literature to develop guidelines. • These recommendations provide an evidence-based framework for lower grade gliomas. Postoperative management of lower grade gliomas (grade 2 and 3) is heterogeneous. The American Radium Society's brain malignancies panel systematically reviewed and evaluated the literature to develop consensus guidelines addressing timing of postoperative therapy, monotherapy versus combined modality therapy, type of chemotherapy used with radiotherapy, and radiotherapy dose. Thirty-six studies were included. Using consensus methodology (modified Delphi), the panel voted upon representative case variants using a 9-point appropriateness scale to address key questions. Voting results were collated to develop summarized recommendations. Following gross-total surgical resection, close surveillance is appropriate for well-selected grade 2, IDH-mutant oligodendrogliomas or astrocytomas with low-risk features. For grade 2 gliomas with high-risk features or any grade 3 glioma, immediate adjuvant therapy is recommended. When postoperative therapy is administered, radiation and planned chemotherapy is strongly recommended over monotherapy. For grade 2 and 3 IDH-mutant oligodendrogliomas and astrocytomas, either adjunctive PCV (procarbazine, lomustine, vincristine) or temozolomide is appropriate. For grade 3 IDH-mutant astrocytomas, radiotherapy followed by temozolomide is strongly recommended. The recommended radiotherapy dose for grade 2 gliomas is 45–54 Gy/1.8–2.0 Gy, and for grade 3 gliomas is 59.4–60 Gy/1.8–2.0 Gy. While multiple appropriate treatment options exist, these consensus recommendations provide an evidence-based framework to approach postoperative management of lower grade gliomas. [ABSTRACT FROM AUTHOR]

Soil radon anomaly is a common phenomenon in karst areas. In this paper, the geochemical behavior of radium (Ra) in the process of carbonate rock weathering and soil formation was used to reveal the accumulation mechanism of soil radon. In the karst area and non-karst area, 24 soil points were collected to measure radon and radium, and a carbonate weathering profile was collected in the karst area. The research showed that: (1) the theoretical radon value obtained from Ra is far greater than the radon value measured on site, indicating that soil Ra can provide a potential source for the source of soil Rn; (2) through the study of the geochemical behavior of Ra during the weathering process, it was found that Ra was significantly enriched during carbonate weathering. This paper deepened the understanding of the geochemical behavior of radionuclides (Ra, Rn) in karst environments. [ABSTRACT FROM AUTHOR]

Copyright of Review of the Bulgarian Geological Society is the property of Bulgarian Geological Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The measurement of uranium ore samples by high-resolution gamma-ray spectroscopy requires long measurement time and expensive high-purity germanium detectors. In this work, we present the possibility to measure uranium concentration by low-resolution gamma-ray spectrometry with an easy-to-operate and cost-effective NaI(Tl) detector. This method is based on the analysis of two energy bands of the NaI gamma spectrum, which allows estimating a possible “U/Rn” imbalance between the top (238U and its daughters up to 230Th) and the bottom (226Ra, 222Rn and their daughters) of the 238U decay chain in roll-front deposits. Indeed, in case of secular equilibrium, more than 95% of gamma rays emitted by uranium ores come from 214Pb and 214Bi isotopes, which are in the backend of the 238U chain. Consequently, a disequilibrium in the chain might produce an overestimation of uranium concentration if U/Rn < 1, or an underestimation if U/Rn > 1. Therefore, the estimation of the disequilibrium between the beginning and the end of the chain represents a crucial issue in uranium mining and exploitation. Finally, the uranium concentration is derived from the U/Rn activity ratio and from the “Rn” activity of the backend chain that is measured by conventional gamma-ray spectroscopy with the 609-keV peak of 214Bi. The total uncertainty is less than 30% within a few minutes of acquisition, and we observe a very good agreement with inductively coupled plasma mass spectrometry (ICP-MS) analyses performed on real samples. [ABSTRACT FROM AUTHOR]

Simple Summary: Radium-223 prolongs overall survival in metastatic castration-resistant prostate cancer patients with bone metastases. However, prognosis after Radium-223 administration varies among patients. One possible reason for this heterogeneity could rely on the suboptimal selection of patients with unfavourable prognostic factors. Moreover, in 2018, the European Medicines Agency limited the Radium-223 prescription to patients pre-treated with at least two systemic therapies or ineligible for any systemic treatment and more than six bone lesions. This moved Radium-223 treatment to the later stages of the disease, making the patient selection process even more challenging. In the BIO-Ra study, we previously combined peripheral inflammatory indices and clinical factors in a composite score able to stratify the prognosis of these patients since baseline. In the present study, the BIO-Ra score was also a reliable prognostic tool in the current clinical scenario, with a potential added value in the patient's selection for Radium-223 treatment. The multicentric retrospective BIO-Ra study combined inflammatory indices from peripheral blood and clinical factors in a composite prognostic score for metastatic castration-resistant prostate cancer patients receiving Radium-223 (Ra-223). In the present study, we evaluated (i) the prognostic power of the BIO-Ra score in the framework of the restricted use of Ra-223 promoted by the European Medicines Agency in 2018; (ii) the treatment completion prediction of the BIO-Ra score. Four hundred ninety-four patients from the BIO-Ra cohort were divided into three risk classes according to the BIO-Ra score to predict the treatment completion rate (p < 0.001 among all the three groups). Patients receiving Ra-223 after restriction (89/494) were at later stages of the disease compared with the pre-restriction cohort (405/494), as a higher percentage of BIO-Ra high-risk classes (46.1% vs. 34.6%) and lower median Overall survival (12.4 vs. 23.7 months, p < 0.001) was observed. Despite this clinically relevant difference, BIO-Ra classes still predicted divergent treatment completion rates in the post-restriction subgroup (72%, 52.2%, and 46.3% of patients belonging to low-, intermediate-, and high-risk classes, respectively). Although the restricted use has increased patients at higher risk with unfavourable outcome after Ra-223 treatment, the BIO-Ra score maintains its prognostic value. [ABSTRACT FROM AUTHOR]

Alpha and beta particulate radiation are used for non-treated neoplasia, due to their ability to reach and remain in tumor sites. Radium-223 (223Ra), an alpha emitter, promotes localized cytotoxic effects, while radioactive gold (198Au), beta-type energy, reduces radiation in the surrounding tissues. Nanotechnology, including several radioactive nanoparticles, can be safely and effectively used in cancer treatment. In this context, this study aims to analyze the antitumoral effects of [223Ra]Ra nanomicelles co-loaded with radioactive gold nanoparticles ([198Au]AuNPs). For this, we synthesize and characterize nanomicelles, as well as analyze some parameters, such as particle size, radioactivity emission, dynamic light scattering, and microscopic atomic force. [223Ra]Ra nanomicelles co-loaded with [198Au]AuNPs, with simultaneous alpha and beta emission, showed no instability, a mean particle size of 296 nm, and a PDI of 0.201 (±0.096). Furthermore, nanomicelles were tested in an in vitro cytotoxicity assay. We observed a significant increase in tumor cell death using combined alpha and beta therapy in the same formulation, compared with these components used alone. Together, these results show, for the first time, an efficient association between alpha and beta therapies, which could become a promising tool in the control of tumor progression. [ABSTRACT FROM AUTHOR]

This paper reviews the history of the radium dial workers in the United States, summarizes the scientific progress made since the last evaluation in the early 1990s, and discusses current progress in updating the epidemiologic cohort and applying new dosimetric models for radiation risk assessment. The discoveries of radiation and radioactivity led quickly to medical and commercial applications at the turn of the 20th century, including the development of radioluminescent paint, made by combining radium with phosphorescent material and adhesive. Workers involved with the painting of dials and instruments included painters, handlers, ancillary workers, and chemists who fabricated the paint. Dial painters were primarily women and, prior to the mid to late 1920s, would use their lips to give the brush a fine point, resulting in high intakes of radium. The tragic experience of the dial painters had a significant impact on industrial safety standards, including protection measures taken during the Manhattan Project. The dial workers study has formed the basis for radiation protection standards for intakes of radionuclides by workers and the public. The mortality experience of 3,276 radium dial painters and handlers employed between 1913 and 1949 is being determined through 2019. The last epidemiologic follow-up was 30 years ago when most of these workers were still alive. Nearly 65% were born before 1920, 37.5% were teenagers when first hired, and nearly 50% were hired before 1930 when the habit of placing brushes in mouths essentially stopped. Comprehensive dose reconstruction techniques are being applied to estimate organ doses for each worker related to the intake of 226Ra, 228Ra, and associated photon exposures. Time dependent dose-response analyses will estimate lifetime risks for specific causes of death. The study of radium dial workers is part of the Million Person Study of low-dose health effects that is designed to evaluate radiation risks among healthy American workers and veterans. Despite being one of the most important and influential radiation effects studies ever conducted, shifting programmatic responsibilities and declining funding led to the termination of the radium program of studies in the early 1990s. Renewed interest and opportunity have arisen. With scientific progress made in dosimetric methodology and models, the ability to perform a study over the entire life span, and the potential applicability to other scenarios such as medicine, environmental contamination and space exploration, the radium dial workers have once again come to the forefront. [ABSTRACT FROM AUTHOR]

In this paper, we present the variation of natural radioactivity in soil and water samples of Tehri Garhwal district of Garhwal Himalaya. The soil and water samples collected from different locations were studied and analyzed using Gamma ray spectrometry and Laser Fluoremetry techniques, respectively. The activity concentrations 226Ra, 232Th and 40K in the soil samples were found to vary 31 ± 6 to 67 ± 7 Bq kg−1 with an average 46 Bq kg−1, 38 ± 7 to 86 ± 10 Bq kg−1 with an average of 52 Bq kg−1 and 612 ± 120 to 1277 ± 168 Bq kg−1 with an average of 902 Bq kg−1, respectively. Uranium concentration in water samples was found to vary from BDL to 2 ppb with an average 0.6 ppb. The above measured values uranium in drinking water ware also be compare the uranium concentrations in drinking water in Ukimath area. The measured values of activity concentrations in the soil and water samples were found within permissible limits. [ABSTRACT FROM AUTHOR]

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