Radionuclide Research Articles

Difficult Diagnosis of Spontaneous Intracranial Hypotension with Nausea and Lower Abdominal Pain as Main Complaints: A Case Report

Background and Clinical Significance: Symptoms of spontaneous intracranial hypotension include orthostatic headaches due to decreased cerebrospinal fluid (CSF) levels. Here, we present a 24-year-old female admitted to an obstetrics and gynecology department with primary complaints of lower abdominal pain and dysmenorrhea with subsequent diagnosis of spontaneous intracranial hypotension (SIH). Case Presentation: The patient had experienced nausea and lower abdominal pain independent of her menstrual cycle 5 days before admission, for which she visited the emergency department 3 days later. On admission, her symptoms were temporarily relieved by administering analgesics; thus, she was discharged. However, later, the symptoms worsened. Consequently, she returned to the emergency department for further evaluation, including blood tests, imaging, and endoscopy, which revealed no nausea- or abdominal pain-related organic abnormalities. On day 10, she developed a headache, aggravated by lying in the supine position and improved by sitting. Additional history revealed a diagnosis of SIH owing to the worsening abdominal pain in the supine position. An 111In CSF cavity scintigram showed no spinal fluid leakage; early intrabladder radioisotope (RI) accumulation was observed, and the residual 24 h CSF cavity RI was >30%. At a referral specialist hospital, an epidural saline infusion test was performed, which improved her headache and lower abdominal pain. Blood patch therapy improved her lower abdominal pain, headache, and dysmenorrhea. Conclusions: The final diagnosis was SIH, with symptoms attributed to CSF depletion. The patient also experienced rare paradoxical postural-related headaches and lower abdominal pain, aggravated by lying in the supine position, contributing to the final diagnosis.

Legacy of Dr. Saul Hertz

Saul Hertz was a physician and scientist who invented and implemented the use of radioactive iodine (RAI) for medical purposes. The history of the development of this new non-invasive and effective method of treatment began in 1936, when Saul Hertz asked Karl Compton, president of the Massachusetts Institute of Technology: "Is it possible to artificially make iodine radioactive?" at the scientific session. The positive response was the beginning of Saul Hertz’s research in the field of nuclear medicine. Together with physicist Arthur Roberts, he studied the pharmacokinetics of radioactive isotopes of iodine and the possibility of using them for the diagnosis and treatment of thyroid disease (TD). In 1938, with the release of 131I, which emits gamma and beta rays and has a half-life of 8 days, RAI could be used not only in experiments, but also in clinical practice. On March 31, 1941, Dr. Saul Hertz performed the first RAI therapy for thyrotoxicosis. Nowadays, March 31 is called World Theranostics Day. Subsequently, Saul Hertz became the founder of the radionuclide treatment of TD, and based on the results of his work, the principles of RAI therapy for differentiated TD were developed. Currently, there are Dr. Saul Hertz Archives in Greenwich (Connecticut, USA) that store the works of this great physician and scientist.

Determination of Lichens’ Bioaccumulation Capacity for Radioactive Isotopes Under Laboratory Conditions as a Basis for Their Application as Biomonitors

This study investigates the bioaccumulation capacity of the lichen Cladonia uncialis for radioactive isotopes, aiming to establish its potential as a biomonitor. Conducted under controlled laboratory conditions, the experiment utilised gamma-emitting isotopes to simulate fallout. The lichens were exposed to varying concentrations of these isotopes in three aquariums. The results demonstrated that the bioaccumulation of 54Mn, 57Co, 60Co, 65Zn, 137Cs, and 241Am by C. uncialis was proportional to their initial deposition levels, and this occurred in the first days of the experiment. Analysis of isotope activity in washed and unwashed lichens showed that retention primarily occurred intracellularly, indicating effective bioaccumulation. The study derived the Aggregated Transfer Coefficient (Tag) for each isotope, which ranged from 0.34 to 0.64, and the absorption capacity of the elements increased in the following order: 54Mn < 57Co < 60Co ≤ 65Zn < 241Am < 137Cs. Absorption efficiency, amounting to approximately 50% for 137Cs and 241Am, highlights the potential for lichens to serve as reliable biomonitors for environmental monitoring and estimation of deposition when knowing only the activity of the isotopes in lichen.

Effective Removal of Sr2+ Ions by K2SbPO6/Polyacrylonitrile Composite Microspheres

90Sr is one of the highly radioactive and hazardous nuclides in nuclear waste liquids. The high water solubility and mobility of 90Sr2+ ions make it difficult to effectively remove 90Sr from the complex aqueous environment. Herein, K2SbPO6, a phosphatoantimonate ion exchange material with an excellent removal ability for Sr2+ ions, has been organically granulated with polyacrylonitrile (PAN) by an automated method to form K2SbPO6/PAN composite microspheres. The K2SbPO6/PAN microspheres with radiation resistance exhibit a high maximum adsorption capacity (qmSr) of 131.15 mg g−1 for Sr2+ ions and retain the high removal rate (RSr) in a wide pH range (pH = 3–12). It is important that K2SbPO6/PAN microspheres could efficiently treat Sr2+ ions solutions in a dynamic adsorption manner even at 970 bed volumes (RSr > 81%). This work paves the way for the preparation of low-cost ion exchange materials with the advantages of regular shape and easy operation by a simple and fast method and the practical application of powdered ion exchange materials.

A study on the performance of enhancing environmental protection from molecular iodine using granular impregnated activated carbon.

Environmentally hazardous radioactive isotopes of iodine may be released from a nuclear power plant as a by-product of uranium fission. The efficient and safe capture of volatile radioiodine is of great significance in the history of nuclear power plants. Due to its high volatility and carcinogenic characteristics, elimination of iodine gas (I2) from air is the need of the hour from an environmental and health point of view. In this work, the trapping of molecular iodine has been studied using porous adsorbents such as activated carbon (AC) and activated carbon impregnated with metals or triethylenediamine (TEDA). Impregnated activated carbons (IACs) chemically react with iodine through SN2 mechanism. The physicochemical and structural characterization of raw activated carbon (RAC) and impregnated activated carbons (IACs) was done by AAS, SEM, EDX, BET, and XRD. The finding of the breakthrough experimental adsorption showed that the gaseous iodine (50ppm) equilibrium adsorption capacity of the raw AC before and after impregnation increased from 180 to 1044mg/g mL at a condition of 60°C. Furthermore, metal IAC was highly adsorbent at high temperatures (80°C) due to its stability, and it adsorbed up to 576mg/g mL iodine at a maximum. The breakthrough study examined that the adsorption capacity of iodine enhanced up to 19% for metal and 26% for metal-TEDA IAC as compared to RAC. Adsorption equilibrium data were well described by the Langmuir model, and the kinetics study was demonstrated by the second-order model. Thermodynamic parameters demonstrated that this is an exothermic and spontaneous reaction. This study explored the parameters of a filter such as adsorption capacity and saturation time at which no more pollutant gas can be captured. Finally, the findings demonstrate that these adsorbents may be capable of adsorbing large amounts of gaseous iodine.

Total alpha radioactivity in fertilizers used in the Indian state of West Bengal using CR-39 SSNTDs: Presentation of a comparative view for different types of fertilizers

Use of fertilizers in agriculture soils is a worldwide practice to increase the yield of agricultural products. Fertilizers may contain radioactive elements may be present along with plant’s nutrients in fertilizers. Migrated radioactive elements from the fertilized soils can find their entry into the environment and human body through several ways, which may lead to induce a potential radiological risk to human health. In the present study, total alpha radioactivity concentration in 68 samples of 18 different types of organic and inorganic fertilizers which are commonly used for cultivation in West Bengal and other states of India has been measured using a track-etch technique. Calibration of the CR-39 track detectors used in this measurement has been done using a distributed alpha-radioactive reference source material of IAEA-448 soil, obtained from Reference Materials Group of International Atomic Energy Commission (IAEA). The obtained source mass dependent calibration factors of CR-39 detectors have been used to estimate the alpha radioactivity of the fertilizer samples eliminating the self-absorption of alpha-particles in the sample. The estimated alpha radioactivity values have been found to vary from 29.4 Bq.kg-1 to 114.2 Bq.kg-1, 2.2 Bq.kg-1 to 13.1 Bq.kg-1 and 485.0 Bq.kg-1 to 1125.8 Bq.kg-1 respectively for organic, non-phosphatic and phosphatic fertilizers. The highest alpha radioactivity is exhibited by phosphatic fertilizers and lowest alpha radioactivity is exhibited by non-phosphatic fertilizers. Alpha radioactivity is found to be strongly correlated with phosphate content of the fertilizers. The alpha radioactivity values obtained in our study are consistent with the studies reported worldwide with few exceptions. Considering radiological as well as other aspects, farmers should be encouraged to use non-phosphatic fertilizers in combination and try to avoid phosphatic fertilizers as far as practicable.

Validation of assay for measuring acetyl-coenzyme a carboxylase activity in grasses using malachite green

Acetyl-CoA carboxylase (ACCase) is one of the most important enzymes as a herbicide target in gramineous plant species, however, assay methods for the enzyme are primarily limited to those using radioisotopes (RI). Typically, the measurement method that uses RI necessitates specialized facilities and equipment, and involves complex procedures throughout the experiment. As another method for detecting ACCase activity, the colorimetric method using malachite green (MG) is also known. However, reports on this method are limited, and information regarding the simplicity of the procedure and the scope of its application remains unclear. To better understand the method using MG and to develop a simpler assay method, crude enzymes extracted from various target-site resistant (TSR) biotypes of blackgrass (Alopecurus myosuroides) were examined in enzyme inhibition tests. As a result, this method was able to accurately detect the relationship between the chemical classes of ACC inhibitors and cross-resistance to specific TSRs. Moreover, the ACCase activity of other grass species was also examined using this method. By using crude enzymes from various species and a commercially available phosphatase kit containing MG, ACCase activity was detectable with good accuracy. In addition, enzyme inhibition studies using ACCase inhibiting herbicides revealed that this method reproduced results similar to those obtained with the RI method. The Z′-factor, an index of high-throughput screening (HTS), was around 0.7, indicating that it is an excellent screening system. These results suggest that the assay method using MG is very simple, labor-saving, and accurate with a throughput much higher than that of the existing RI method. Therefore, it is strongly suggested that the method could replace the RI method in most cases. These results indicate that it is applicable to HTS for ACCase inhibitors.

Auxiliary electrodialysis realizes over 50 times concentration of nuclide ions from liquid effluents of nuclear power plants

Rapid and highly effective enrichment of nuclides containing liquid effluent is crucial for online monitoring of radioactive trace elements from nuclear power plants (NPPs). In this study, auxiliary electrodialysis (AED) was proposed for high enrichment of trace ions in the liquid effluents of NPPs. The effects of the auxiliary ion type and concentration and the operating voltage on the AED concentration performance were investigated. When the volume ratio of the solution was 140: 1 with 0.03 mol/L HNO3 as the auxiliary electrolyte, most of the nuclide ions were concentrated more than 50 times after the two-stage electrodialysis experiment. In the first-stage electrodialysis, the concentration of most ions, with the exception of the higher valence ions (Ru3+ and Zr4+), tends to increase with increasing operating voltage. The diluate stream volume could be minimized to 98.8% with a total energy consumption of 9.5 kWh/m3. By considering the impact of boron in the liquid effluents, more than 52 times concentrations could still be achieved by extending the running time of the first-stage ED (increasing the ion removal rate). The transmembrane fluxes of various cations decreased in the order of Cs+ > Sr2+ > Zn2+ > Co2+ ≈ Ni2+ ≈ Mn2+ > Fe3+ > Cr3+ > Ru3+ > Zr4+, which is attributed to the experimental operating parameters and ionic properties. This research provided a viable technique for rapid and highly effective enrichment of nuclides containing liquid effluents for both radioactive element monitoring and wastewater volume reduction.

Investigation of nuclide inventory of cladding material irradiated in the Goesgen PWR core

A characterization of the spent nuclear fuel (SNF) for its radionuclide (RN) inventory is vital for various back-end stages of the nuclear fuel cycle. It concerns both the fuel and the metallic (i.e., cladding and structural material) components of the spent fuel assemblies, where different calculation approaches and methods should be deployed for their characterization. This study concentrates on fuel traces and other impurities within the cladding. During the operating cycles, the Zircaloy cladding is exposed to a considerable amount of irradiation. The impact of the exposure should be checked to assure the integrity of the cladding and thus the safety of the stored spent fuel. Within the work package “Spent Nuclear Fuel Characterization and Evolution until Disposal” (SFC) of the EURAD project, dedicated samples were produced, irradiated and the radionuclide inventory of the cladding was analysed and compared. In parallel a blind test was performed, in which different partners used different codes to simulate the irradiation quantity. The blind test showed good agreement between most of the codes, in particular in view of the small amount of the evolved fuel traces. Furthermore, the presence of actinides, caused by precipitation of uranium on the inner surface of the cladding during manufacturing, was found to be negligible in comparison to precipitation of traces of fuel pellets on the cladding during operation. The good agreement between the simulating codes enables to depict further the initial amount of alloying elements of the cladding material itself in a better manner. In particular specific isotopes of cobalt, nickel and iron, which are directly connected to the unique properties of each cladding material can be better identified based on the accurate measuring techniques used in this study.

Noise-aware dynamic image denoising and positron range correction for Rubidium-82 cardiac PET imaging via self-supervision

Rubidium-82 (82Rb) is a radioactive isotope widely used for cardiac PET imaging. Despite numerous benefits of 82Rb, there are several factors that limits its image quality and quantitative accuracy. First, the short half-life of 82Rb results in noisy dynamic frames. Low signal-to-noise ratio would result in inaccurate and biased image quantification. Noisy dynamic frames also lead to highly noisy parametric images. The noise levels also vary substantially in different dynamic frames due to radiotracer decay and short half-life. Existing denoising methods are not applicable for this task due to the lack of paired training inputs/labels and inability to generalize across varying noise levels. Second, 82Rb emits high-energy positrons. Compared with other tracers such as 18F, 82Rb travels a longer distance before annihilation, which negatively affect image spatial resolution. Here, the goal of this study is to propose a self-supervised method for simultaneous (1) noise-aware dynamic image denoising and (2) positron range correction for 82Rb cardiac PET imaging. Tested on a series of PET scans from a cohort of normal volunteers, the proposed method produced images with superior visual quality. To demonstrate the improvement in image quantification, we compared image-derived input functions (IDIFs) with arterial input functions (AIFs) from continuous arterial blood samples. The IDIF derived from the proposed method led to lower AUC differences, decreasing from 11.09% to 7.58% on average, compared to the original dynamic frames. The proposed method also improved the quantification of myocardium blood flow (MBF), as validated against 15O-water scans, with mean MBF differences decreased from 0.43 to 0.09, compared to the original dynamic frames. We also conducted a generalizability experiment on 37 patient scans obtained from a different country using a different scanner. The presented method enhanced defect contrast and resulted in lower regional MBF in areas with perfusion defects. Lastly, comparison with other related methods is included to show the effectiveness of the proposed method.

Synthesis of some anion exchange resins for selective separation of 99Mo and 131I: A comparative study

ABSTRACT Amination of styrene-divinylbenzene (SDVB) copolymers is a traditional process for preparing strong anion exchange resins that can greatly improve their performance and applications. In the present investigation, poly(styrene-co-divinyl benzene) copolymers functionalized by various amino groups were synthesized by the amination route. The performance of synthesized exchange resins for the separation and recovery of active Mo(VI) and I(I) isotopes from their aqueous solutions was compared to that of three commercial ion exchange resins, used in the actual production of these radioisotopes in the Radioisotopes Production Facility. The morphology and structural properties of the synthesized copolymers as well as the commercial reference resins were characterized using FT−IR, SEM, TG, and XPS. The results demonstrate that the copolymer was successfully functionalized with amino groups, where trimethylamine produced amination greater than triethylamine. Furthermore, the thermal stability of synthesized anion exchanges was significantly higher than that of commercial beads. The synthesized polymer networks presented excellent radiation stability under applied experimental conditions. Compared to the reference resins, the synthesized co-polymeric beads showed enhanced adsorption capability for MoO4 2− and I− ions from an aqueous solution. Further, the uptake affinity of the networks aminated with trimethylamine for both radioisotopes, in optimal conditions, was greater than that of triethylamine aminated beads. The sorption mechanism was inferred through FT−IR and XPS analysis, and the results clarified that the separation of both radioisotopes was substantially related to the amine functional groups on the resin framework. The spectroscopic analysis illustrated that one molybdenum ion (in the form of MoO4 2−) was subjected to an ion-exchange interaction and two Cl− ions in the amine resin. A similar exchange mechanism was predicted for I− with Cl− ions. Further, the enhanced sorption of Mo(VI) could be additionally attained through coordination interactions with N atoms in the amine groups that have good chelating capability toward metal ions. The reusability performance of the synthesized exchange resins is better than that of the commercial reference resins, where they could be effectively regenerated for up to five cycles. Finally, this study presents a new technique for the separation and recovery of Mo(VI) and I(I) from irradiated low-enriched U-targets by employing highly promising amino-modified polystyrene-divinyl benzene microspheres.

Evaluation of Radiation Rates and Health Hazards from Different Cement Types in Pakistan

The raw materials of cement contain radioactive elements that come from natural sources. Members of the decay chains of uranium, thorium, and potassium radioisotope 40K are the primary sources of this radioactivity. The natural radionuclide concentration levels in cement differ greatly depending on different geographic areas. To estimate the radionuclides concentration in cement specimens from twelve diverse Pakistani companies, gamma-ray spectroscopy analysis was used in the study. 226Ra, 232Th, and 40K had activity concentration levels ranging from 18.08 to 43.18 Bq/kg, 16.73 to 23.53 Bq/kg, and 14.24 to 315.22 Bq/kg, respectively. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) threshold for the 226Ra was surpassed by five of the studied samples. The indoor and outdoor dose rates as well as different radiological health hazard indices were also examined. The Indoor Absorbed Dosage (Din) for some of the samples exceeded the permissible limit. These samples also had a high Indoor Effective Lifetime Cancer Risk (ELCR) factor, which makes them unsafe for interior construction purposes. The outdoor dosages as well as the hazard indices were well within the permitted ranges. The outdoor ELCR factor is low for all the cement brands, which makes them safe for exterior construction purposes. The findings were compared with published data from other countries around the globe. Finally, a thorough statistical analysis was performed and Pearson’s Correlation Coefficient (r) exhibited a very strong correlation between the different outdoor and indoor radiological health hazard indices.

Production and purification of molecular 225Ac at CERN-ISOLDE

AbstractThe radioactive nuclide 225Ac is one of the few promising candidates for cancer treatment by targeted-$$\alpha$$ α -therapy, but worldwide production of 225Ac faces significant limitations. In this work, the Isotope Separation On-Line method was used to produce actinium by irradiating targets made of uranium carbide and thorium carbide with 1.4-GeV protons. Actinium fluoride molecules were formed, ionized through electron impact, then extracted and mass-separated as a beam of molecular ions. The composition of the mass-selected ion beam was verified using time-of-flight mass spectrometry, $$\alpha$$ α - and $$\gamma$$ γ -ray decay spectrometry. Extracted quantities of $$^{225}\textrm{Ac}^{19}\textrm{F}_2^{+}$$ 225 Ac 19 F 2 + particles per $$\upmu$$ μ C of incident protons were $$3.9(3)\times 10^7$$ 3.9 ( 3 ) × 10 7 from a uranium carbide target and $$4.3(4)\times 10^7$$ 4.3 ( 4 ) × 10 7 for a thorium carbide target. Using a magnetic mass separator, the long-lived contamination 227 Ac is suppressed to $$<5.47\times 10^{-7}$$ < 5.47 × 10 - 7 (95% confidence interval) with respect to 225Ac by activity. Measured rates scale to collections of 108 kBq$$\upmu$$ μ A$$^{-1}$$ - 1 h$$^{-1}$$ - 1 of directly produced $$^{225}\textrm{Ac}^{19}\textrm{F}_2^{+}$$ 225 Ac 19 F 2 + .

Exploring of the suitability of garnets for immobilizing nuclear waste and radiation shielding

In this study, the structural, chemical composition and gamma and nuclear shielding properties of some garnets were investigated. The experimental studies were made on the mass attenuation coefficients (MAC), linear attenuation coefficients (LAC), mean free path (MFP), half-value layer (HVL), effective atomic numbers (Zeff) and the radiation protection efficiency (RPE) in the high energy region. The fast neutron removal cross sections (ΣR), exposure buildup factors (EBF) were theoretically determined. The neutron absorption equivalent dose was measured of the garnet by 241Am–Be fast neutron source. It may be concluded that P1.21 has better photon shielding than the other samples investigated. The equivalent dose rate absorbed by the P1.21 garnet sample was found to be 36.80 % μSv/h and the P1.21 sample shows promise as a neutron shielding option. Also, the detection of inclusion minerals were made by EPMA and SEM analysis. It is observed that P1.21 sample is pyrope, P1.3 sample is andradite and P1.6 sample is grossular series. Also, according to ICP-MS results, it is possible to say that the P1.21 sample, which contains high amount of uranium, thorium, Y and Zr and has a high radiation absorption capacity, is a potential garnet structure for nuclear waste immobilization. Garnet's crystal structure and chemical durability enable safe containment and long-term storage of radioactive elements, facilitating their secure disposal.

Spectroscopic analysis of alpha particles from radioactive nuclides with CR-39 plastic nuclear track detectors.

A spectroscopy method of alpha particles with the track geometry parameters in CR-39 plastic nuclear track detectors is proposed. The relationship between the track registration sensitivity and incident angle of each etch pit is analyzed. The components of alpha particles emitted from radon, thoron and 241Am can be roughly separated when the etching level is not exceeded beyond the range in CR-39. This work aims at improving the dose assessment accuracy from exposure to indoor radon and thoron.

Trop2-Targeted Molecular Imaging in Solid Tumors: Current Advances and Future Outlook.

Trophoblast cell surface antigen 2 (Trop2), a transmembrane glycoprotein, plays a dual role in physiological and pathological processes. In healthy tissues, Trop2 facilitates development and orchestrates intracellular calcium signaling. However, its overexpression in numerous solid tumors shifts its function toward driving cell proliferation and metastasis, thus leading to a poor prognosis. The clinical relevance of Trop2 is underscored by its utility as both a biomarker for diagnostic imaging and a target for therapy. Notably, the U.S. Food and Drug Administration (FDA) has approved sacituzumab govitecan (SG), a novel Trop2-targeted agent, for treating triple-negative breast cancer (TNBC) and refractory urothelial cancer, highlighting the significance of Trop2 in clinical oncology. Molecular imaging, a powerful tool for visualizing and quantifying biological phenomena at the molecular and cellular levels, has emerged as a critical technique for studying Trop2. This approach encompasses various modalities, including optical imaging, positron emission tomography (PET), single photon emission computed tomography (SPECT), and targeted antibodies labeled with radioactive isotopes. Incorporating Trop2-targeted molecular imaging into clinical practice is vital for the early detection, prognostic assessment, and treatment planning of a broad spectrum of solid tumors. Our review captures the latest progress in Trop2-targeted molecular imaging, focusing on both diagnostic and therapeutic applications across diverse tumor types, including lung, breast, gastric, pancreatic, prostate, and cervical cancers, as well as salivary gland carcinomas. We critically evaluate the current state by examining the relevant applications, diagnostic accuracy, therapeutic efficacy, and inherent limitations. Finally, we analyze the challenges impeding widespread clinical application and offer insights into strategies for advancing the field, thereby guiding future research endeavors.

What work does 'contamination' do? An agential realist account of oil wastewater and radium in groundwater.

Oil wastewater often contains high levels of radium, a carcinogenic and radioactive element. This article closely engages with two investigations of radium in groundwater downstream from oil wastewater storage pits. While one investigation found that radium did not travel beyond the storage pits, the other found evidence of elevated radium some two kilometers downstream. With an agential realist analysis, we resolve these differences, showing that these two experimental apparatuses defined and mobilized two different phenomena of radium, and of radium-as-contaminant. What geologists call 'rock-water interactions' are materially meaningful intra-actions. Far from being a mere philosophical gloss on otherwise conventional science, the 'intra-' signifies that, in these processes, the sediment and the groundwater are bringing each other into being. Groundwater sampling entails a specific set of intra-actions with the subsurface that enact different agential cuts. In addition, a geochemical focus on objects, rather than relations, also constrains understandings of chemical harm and accountability. These concepts do not only affect experimental apparatuses; rather, they come into being through and with each other. Therefore, rigorous approaches to groundwater and remediation do not lie in the pull to reify individual groundwater constituents, or to arbitrate between 'contaminant' and 'contaminated'. Rather, rigorous approaches lie in the role of chemical relations in constituting specific groundwater phenomena. We elaborate three aspects of these relations: the constitution of radium-as-isolated-element through the ontological work of sampling schema, the formation of scale and attendant spacetimematterings within experimental apparatuses, and the work of contamination logics within conceptualizations of chemical harm. This analysis has major implications for understanding the potential harm of oil wastewater to groundwater.

Optimization of pretreatment protocol for strontium-90 analysis in marine fish bone samples.

For systematic monitoring of radioactive nuclides in marine products, this study aimed at streamlining and simplifying the analysis method for the prominent radioisotope, strontium-90 (90Sr). The DGA chelate solid-phase extraction technique was employed for enhanced efficiency. The study focused on optimizing the necessary pretreatment procedures while minimizing the steps involving HNO3 leaching. This protocol enabled the quantitative recovery of strontium, and it facilitated a rapid analysis without the need for a time-consuming evaporation step and without waiting for secular equilibrium between 90Sr and its progeny to be reached. The method incorporating the optimized pretreatment protocol was applied to three diverse marine fish species and the accurate quantification of 90Sr at background levels in surface seawater was achieved. The method obtained concentrations in bone samples from these species that ranged from 0.036 to 0.120 mBq per kg-dry, and chemical yield values were notably high, ranging from 87.7% to 92.5%.

Chemical form dependent iodine transfer from seawater into seaweed and abalone.

Nuclear fuel reprocessing plant releases several kinds of radioactive nuclides, mainly 3H and 129I, into the oceans. Radio iodine causes thyroid dose. Iodine accumulates in several marine species such as wakame and abalone, which are food materials. Therefore, an analysis of iodine behavior in the marine environment is important to assess the impact of 129I. Iodine in seawater exists mainly in two chemical forms: iodide (I-) and iodate (IO3-). Their environmental behaviors are different. Thus, understanding these behaviors is important to assess the environmental behavior of total iodine. In this study, iodate and iodide transfer between seawater and abalone (Haliotis discus hannai) with 125I tracer was observed.

Assessment of Groundwater Quality in the Semi-Arid Environment: Implications of Climate Change

The hydrogeochemical properties and evolution of groundwater in the Essaouira syncline basin in northwestern Morocco were investigated in this study, with a total of 447 samples during different campaigns (April 2017, May 2018, March 2019, and July 2020). These samples were analyzed for major ions and stable and radioactive water isotopes (δ2H, δ18O, and 3H). With decreasing rainfall from climate change in Morocco, it is crucial to assess the sustainability of groundwater reserves. This shortage leads to the degradation of water and soil quality. To ensure sustainable water management and preserve the environment in the study area, it is necessary to assess groundwater quality for drinking and irrigation, take precautions, and establish management plans. This study assessed groundwater quality using two water quality index methods (WQI and IWQI). Several natural processes control groundwater mineralization, including the dissolution of evaporite and carbonate minerals, cation exchange phenomena, evaporation, and seawater intrusion. According to the results obtained using the WQI method, all groundwater samples in the study area are generally of poor quality and must be treated before being used for domestic purposes. Based on the results obtained by the IWQI method, the samples are suitable for use as irrigation water, especially for plants resistant to high salinity concentrations. Stable isotope measurements (δ2H and δ18O) indicate that Atlantic precipitation continuously recharges the recharge areas of the Essaouira Basin. Thus, the low values of tritium (3H) in groundwater mean that the freshwater in the Essaouira Basin is ancient.