Search Results (106)

Residential exposure to radon and environmental gamma radiation poses a significant public health concern in uranium-rich regions. The Akmola Region of Kazakhstan, home to one of the world’s largest uranium tailings sites, lacks localized data on seasonal exposure variations and associated health risks. This study assessed indoor radon progeny concentrations and gamma dose rates in 62 dwellings across two settlements—Aqsu and Zavodskoy—in the Akmola Region during autumn 2023 through summer 2024. Using RAMON-02 and Alpharad Plus detectors, seasonal equivalent equilibrium volumetric activity (EEVA) of radon progeny and effective doses were calculated, stratified by presence of a cellar. In Aqsu, ambient dose equivalent rates reached up to 0.55 µSv/h, and winter median EEVA levels exceeded 130 Bq/m³ in some non-cellar homes. Seasonal effective doses peaked in spring (up to 8.82 mSv) in cellar dwellings, with annual doses reaching 23.5 mSv—substantially higher than in Zavodskoy. Although mitigation efforts have reduced exposure in some homes, several cellar dwellings in Aqsu exhibited persistently elevated EEVA, suggesting potential structural vulnerabilities or residual contamination. These findings underscore significant seasonal and structural disparities in radiation exposure and highlight the need for targeted, site-specific interventions to reduce long-term health risks in affected communities. Full article

Cadmium (Cd) is a major co-occurring, highly toxic heavy metal in uranium (U) tailings that poses synergistic risks to ecological and human health. This study aimed to investigate the effects of Cd on U accumulation and phytotoxicity in plants using radish (Raphanus sativus L.) as a model organism under hydroponic conditions. Treatments included U alone (25 μM and 50 μM), low-concentration Cd alone (10 μM), and U + Cd co-treatments (U25 + Cd and U50 + Cd). Results revealed that exposure exerted minimal phytotoxicity, whereas U treatment induced severe root toxicity, characterized by cell death and an 11.9–63.8% reduction in root biomass compared to the control. Notably, U + Cd co-treatment exacerbated root cell death and biomass loss relative to U alone. Physiologically, elevated U concentrations significantly increased superoxide anion radical (O₂⁻) production rate, hydrogen peroxide (H₂O₂) content, and malondialdehyde (MDA)—a marker of oxidative damage—inducing cellular oxidative stress. Under U + Cd co-treatment, O₂⁻ production, H₂O₂ content, and MDA levels in radish roots were all significantly higher than under U alone. Concurrently, activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], and peroxidase [POD]) were lower in U + Cd-treated roots than in U-treated roots, further exacerbating oxidative damage. Regarding heavy metal accumulation, the content of U in radish under U + Cd treatment was significantly higher than that in the U treatment group. However, no significant differences were observed in the expression of uranium (U)-related transport genes (MCA1, MCA3, and ANN1) between the single U treatment and the U-Cd co-treatment. Notably, the inhibitory effect of NRAMP3—a gene associated with Cd transport—was weakened under the coexistence of U, indicating that U exacerbates toxicity by promoting Cd transport. This study shows that Cd appears to enhance the accumulation of U in radish roots and exacerbate the phytotoxicity of U. Full article

3,4-dihydroxybenzenesulfonyl-functionalized polyethyleneimine (PS), a novel polymeric chelator, was synthesized by conjugating 3,4-dihydroxybenzenesulfonyl (CAM) groups with branched polyethyleneimine (BPEI, MW = 600 Da) via N-acylation. PS demonstrated a high uranium adsorption capacity of 78.08% at a concentration of 4 mg/mL, accompanied by significant selectivity over competing ions such as Ca²⁺, Zn²⁺, and Cu²⁺. Notably, in competitive adsorption experiments, PS exhibited a uranium adsorption rate of 59.49%, which was 3.95 times higher than that of calcium (15.06%) in the Ca²⁺ system. Cytotoxicity assays revealed enhanced biocompatibility (IC₅₀ = 86.98 μg/mL), surpassing CaNa₃-DTPA 3.7-fold. In a uranium exposure model (200 μg/mL), PS significantly improved cell survival rates and reduced intracellular uranium levels by 77.37% (immediate administration) and 64.18% (delayed administration). These findings establish PS as a potent and safe polymeric chelator for uranium decorporation, offering a promising strategy for mitigating the hazards of radioactive materials. Full article

The rapid development of the nuclear industry and mining has increased environmental radioactive contamination, posing potentially ecological risks and health threats to humans. Uranium compounds are known to exhibit selective nephrotoxicity, but their toxicological processes and mechanisms still remain poorly understood and controversial. In this study, the uranyl-induced toxicity in human renal tubular epithelial cells (HK-2) were explored using flow cytometry, DAPI staining, and comet assays. Our results demonstrate that uranium exposure primarily triggers apoptosis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment and protein–protein interaction (PPI) analyses revealed significant associations with DNA damage. Moreover, aberrant expression of ABC transporters (e.g., ABCB7) and mitochondrial-related proteins confirms uranium-induced mitochondrial dysfunction. Gene Ontology functional annotation implicated extrinsic apoptotic signaling pathways in uranium-induced cell death. The downregulation of the UBL5 protein also pointed to endoplasmic reticulum stress-mediated apoptosis. In summary, uranium exposure can induce the apoptosis of HK-2 cells through intrinsic pathways by damaging DNA and mitochondria and disrupting protein synthesis, with secondary contributions from endoplasmic reticulum stress and extrinsic apoptotic signaling. Full article

The Fernald Feed Materials Production Center (FMPC), located in Fernald, Ohio, USA, released radon (Rn) as a byproduct of the processing of uranium materials during the years from 1951 to 1989. Rn is a colorless, odorless gas that emits charged alpha radiation that interacts with cells in the lung and trachea-bronchial tree, leading to DNA damage, mutations, and tumor initiation. The purpose of this project was to use evidence collected by the Fernald Dosimetry Reconstruction Project and other sources to estimate the outdoor Rn exposure to individuals in the community immediately surrounding the FMPC during the years of plant operation. Using previously tabulated source terms, diffusion and meteorological data, and self-reported detailed residential histories, we estimated radon exposure for approximately 9300 persons who lived at more than 14,000 addresses. The results indicated that a portion of the population cohort experiences mean annual Rn exposure exceeding the U.S. Environmental Protection Agency (EPA) action limit of 4 pCiL⁻¹. These exposure estimates support the analysis of the incidence of lung cancer in the Fernald Community Cohort (FCC). Full article

Mineral waters from two tectonically active mountain systems within the Alpine-Himalayan orogenic belt, the Pamir and the Greater Caucasus (Elbrus region), were analyzed for ²²²Rn activity and ²³⁸U concentrations to establish correlations with geological conditions, physicochemical characteristics of water, and to assess the potential health risk associated with ²³⁸U and ²²²Rn. It was found that in mineral waters of the Pamir, the concentrations of ²³⁸U (0.004–13.3 µg/L) and activity of ²²²Rn (8–130 Bq/L) are higher than in the Elbrus area: 0.04–3.74 µg/L and 6–33 Bq/L, respectively. Results indicate that uranium mobility in water is strongly influenced by T, pH, and Eh, but is less affected by the age of host rocks or springs′ elevation, whereas radon activity in waters depends on the age of rocks, spring elevation, ²³⁸U content, and values of δ¹⁸O and δ²H in water. This study reveals fundamental geological distinctions governing uranium and radon sources in the mineral waters of these regions. Isotopic evidence (²²²Rn and ³He/⁴He) demonstrates crustal radon sources prevail in Pamir, whereas the Elbrus system suggests mantle-derived components. The U concentrations do not exceed 30 µg/L, and most water samples (94%) showed ²²²Rn activities below 100 Bq/L, complying with the drinking water exposure limits recommended by the World Health Organization and European Union Directive. However, in intermountain depressions of the Pamirs, at low absolute elevations (~2300 m), radon concentrations in water can increase significantly, which requires special attention and study. Full article

Background/Objectives: This study aimed to evaluate the effects of lung injury induced by insoluble uranium oxide particles on gut microbiota and related metabolites in rats. Methods: The rats were randomly divided into six UO₂ dose groups. A rat lung injury model was established through UO₂ aerosol. The levels of uranium in lung tissues were detected by ICP-MS. The expression levels of the inflammatory factors and fibrosis indexes were measured by enzyme-linked immunosorbent assay. Paraffin embedding-based hematoxylin & eosin staining for the lung tissue was performed to observe the histopathological imaging features. Metagenomic sequencing technology and HM700-targeted metabolomics were conducted in lung tissues. Results: Uranium levels in the lung tissues increased with dose increase. The expression levels of Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), Collagen I, and Hydroxyproline (Hyp) in rat lung homogenate increased with dose increase. Inflammatory cell infiltration and the deposition of extracellular matrix were observed in rat lung tissue post-exposure. Compared to the control group, the ratio of Firmicutes and Bacteroides in the gut microbiota decreased, the relative abundance of Akkermansia_mucinphila decreased, and the relative abundance of Bacteroides increased. The important differential metabolites mainly include αlpha-linolenic acid, gamma-linolenic acid, 2-Hydroxybutyric acid, Beta-Alanine, Maleic acid, Hyocholic acid, L-Lysine, L-Methionine, L-Leucine, which were mainly concentrated in unsaturated fatty acid biosynthesis, propionic acid metabolism, aminoacyl-tRNA biosynthesis, phenylalanine metabolism, and other pathways in the UO₂ group compared to the control group. Conclusions: These findings suggest that uranium-induced lung injury can cause the disturbance of gut microbiota and its metabolites in rats, and these changes are mainly caused by Akkermansia_mucinphila and Bacteroides, focusing on unsaturated fatty acid biosynthesis and the propionic acid metabolism pathway. Full article

Objectives: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with an unclear etiology. This study aimed to assess chronic heavy metal exposure in ALS patients in South Korea by comparing hair concentrations of common (Hg, Pb, Cd) and rare (U, Th, Pt) metals with healthy controls. Methods: Hair samples were collected from 66 ALS patients and 70 healthy individuals at Rodem Hospital between 2022 and 2025. Metal concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS) following standardized washing and digestion protocols. Results: ALS patients showed significantly higher levels of Hg, Pb, Cd, Al, As, and U than controls (p < 0.05). Notably, 40% of ALS patients had Hg levels exceeding 50% of the reference upper limit, compared to only 10% of controls. Elevated levels of uranium and other rare metals were also observed in specific ALS cases. Conclusions: These findings suggest a possible association between heavy metal exposure and ALS in South Korea. Hair analysis may serve as a useful tool for identifying environmental factors contributing to ALS pathogenesis. Full article

Metal exposure is a potential risk factor for amyotrophic lateral sclerosis (ALS). Increasing evidence suggests that elevated levels of DNA damage are present in both familial (fALS) and sporadic (sALS) forms of ALS, characterized by the selective loss of motor neurons in the brain, brainstem, and spinal cord. However, identifying and differentiating initial biomarkers of DNA damage response (DDR) in both forms of ALS remains unclear. The toxicological profiles from the Agency for Toxic Substances and Disease Registry (ATSDR) and our previous studies have demonstrated the influence of metal exposure-induced genotoxicity and neurodegeneration. A comprehensive overview of the ATSDR’s toxicological profiles and the available literature identified 15 metals (aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), nickel (Ni), selenium (Se), uranium (U), vanadium (V), and zinc (Zn)) showing exposure-induced genotoxicity indicators associated with ALS pathogenesis. Genetic factors including mutations seen in ALS types and with concomitant metal exposure were distinguished, showing that heavy metal exposure can exacerbate the downstream effect of existing genetic mutations in fALS and may contribute to motor neuron degeneration in sALS. Substantial evidence associates heavy metal exposure to genotoxic endpoints in both forms of ALS; however, a data gap has been observed for several of these endpoints. This review aims to (1) provide a comprehensive overview of metal exposure-induced genotoxicity in ALS patients and experimental models, and its potential role in disease risk, (2) summarize the evidence for DNA damage and associated biomarkers in ALS pathogenesis, (3) discuss possible mechanisms for metal exposure-induced genotoxic contributions to ALS pathogenesis, and (4) explore the potential distinction of genotoxic biomarkers in both forms of ALS. Our findings support the association between metal exposure and ALS, highlighting under or unexplored genotoxic endpoints, signaling key data gaps. Given the high prevalence of sALS and studies showing associations with environmental exposures, understanding the mechanisms and identifying early biomarkers is vital for developing preventative therapies and early interventions. Limitations include variability in exposure assessment and the complexity of gene–environment interactions. Studies focusing on longitudinal exposure assessments, mechanistic studies, and biomarker identification to inform preventative and therapeutic strategies for ALS is warranted. Full article

Osteoporosis is a major public health concern, particularly among postmenopausal women. Environmental exposure to metals has been proposed as a potential contributor to osteoporosis, but human data remain limited and inconsistent. This study investigated changes in urinary concentrations of 20 metal(loid)s in patients with osteoporosis, as well as the association of these elements with bone mineral density (BMD), in a cohort of 380 postmenopausal women aged 50–70 years from Cascavel, Paraná, Brazil. Demographic, lifestyle, and clinical data were collected, and urinary concentrations of aluminum (Al), barium (Ba), cadmium (Cd), cobalt (Co), cesium (Cs), copper (Cu), mercury (Hg), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), rubidium (Rb), antimony (Sb), selenium (Se), tin (Sn), strontium (Sr), thallium (Tl), uranium (U), and zinc (Zn) were measured by inductively coupled plasma mass spectrometry. BMD was assessed at the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry. Osteoporosis was diagnosed in 73 participants (19.2%). Osteoporotic women had significantly higher urinary concentrations of Cd, Mn, Pb, Sb, Sn, and Zn (p < 0.05). Statistically significant negative correlations were observed between BMD and urinary concentrations of Al, Cd, Hg, Mn, Sb, and U. After adjustment for confounders, elevated urinary concentrations of Cd, Mn, Pb, and Sb remained independently and significantly associated with higher odds of osteoporosis, with Cd (aOR = 1.495; p = 0.026) and Sb (aOR = 2.059; p = 0.030) showing the strongest associations. In addition, women with urinary concentrations above the 90th percentile for both Cd and Sb had a significantly higher prevalence of osteoporosis compared to those with lower levels (44.4% vs. 18.0%; p = 0.011). Longitudinal studies are needed to confirm causality and inform prevention strategies. Full article

Long-term exposure to radon, thoron, and gamma radiation from building materials poses a significant health risk to occupants. Current methods for estimating radiation doses often fail to consider the combined impact of these sources. Based on commonly used building materials available on the Irish market, this paper advocates for the development of a comprehensive dose estimation model that accounts for radon, thoron, and gamma radiation. To achieve this, several models and various scenarios (e.g., ventilation conditions and building characteristics) are integrated to convert radon and thoron gas doses into a common unit recognized in the existing literature. This approach enables the comparison of combined dose values with accepted radiation thresholds for building materials, typically set at 1 mSv, alongside data on material compositions. Previous studies suggested gamma radiation doses in Irish materials are unlikely to exceed 1 mSv annually. Our findings confirm this, showing gamma doses <0.4 mSv for all materials. However, combined radon–thoron doses exceeded thresholds in altered granites (e.g., Galway granite: 3.90 mSv), with thoron contributing ≤93% of total exposure due to uranium/thorium-rich minerals (e.g., monazite, zircon). Ventilation proved critical—high airflow (10 m³/h) reduced thoron doses by 90–95%, while current gamma-focused safety indices (I-index ≤ 1) inadequately addressed combined risks. These results highlight the previously underestimated importance of thoron and the necessity of multi-parameter models for regulatory compliance. The study establishes a novel framework to evaluate holistic radiation risks, urging revised standards that prioritize ventilation strategies and material mineralogy to protect public health in residential and commercial built environments. Full article

This work evaluates the effectiveness of in situ and ex situ passivation methods for mitigating the pyrophoricity of uranium–6 wt.% niobium spherical powders produced via the hydride–dehydride process coupled with plasma spheroidization. Oxide layer thickness was characterized using STEM/EDX, and pyrophoricity was assessed by a UN-recommended test method, which involves directly dropping the powders in the air. In situ passivation, performed by introducing flowing oxygen during spheroidization, produced oxide layers ranging from tens to hundreds of nanometers but resulted in inconsistent pyrophoricity mitigation at lower oxygen flow rates. Ex situ passivation, achieved by slow oxygen exposure over several months, formed uniform oxide layers of approximately 20 nm and consistently mitigated pyrophoricity. Despite requiring higher bulk oxygen content, in situ passivation enables faster processing and control of oxygen, while ex situ passivation achieves superior oxide uniformity with lower oxygen incorporation. These findings highlight the trade-offs between passivation methods and provide a foundation for improving the safety and scalability of reactive metal powder production. Full article

The Mamuju region in West Sulawesi, Indonesia, is a High Background Natural Radiation Area (HBNRA) characterized by a significant enrichment of high field strength elements (HFSEs) and rare earth elements (REEs) within its lateritic deposits. This study investigates the geochemical behavior, mineralogical distribution, and enrichment processes of HFSEs and REEs in lateritic profiles of drill cores and surface samples derived from alkaline volcanic rocks. The mineralogy and geochemical content of HFSEs and REEs in the alkaline bedrocks indicate its potential to become a source of lateritic enrichment. An intense lateritic weathering process leads to the residual accumulation of HFSEs and REEs, particularly in B-horizon soils, where clay minerals and Fe–Al oxides are crucial in element precipitation. Moreover, groundwater redox conditions are a key factor for uranium precipitation in the lateritic profile. The findings provide insight into the potential of lateritic weathering as a natural mechanism for HFSE and REE concentration, contributing to the broader understanding of critical metal resources in Indonesia. These insights have implications for sustainable resource exploration and environmental management in areas with high natural radiation exposure. Full article

Radon is an inert gas produced by the radioactive decay of uranium-238, commonly found in the environment. Radon and its decay products are the main sources of human exposure to radiation from natural sources. When inhaled, radon’s alpha particles impact lung tissue, potentially causing lung cancer by damaging DNA and altering oxidative processes. This review article addresses the need for a deeper understanding of the genetic and molecular changes associated with radon-induced lung cancer, aiming to clarify key genetic mutations and protein markers linked to carcinogenesis. Particular attention in recent studies has been given to mutations in tumor suppressor genes (RASSF1, TP53), oncogenes (KRAS, EGFR), and changes in the expression levels of protein biomarkers associated with inflammation, stress, and apoptosis. Identifying these markers is critical for developing effective screening methods for radon-induced lung cancer, enabling timely identification of high-risk patients and supporting effective preventive strategies. Summarizing current genetic and protein biomarkers, this review highlights the importance of a comprehensive approach to studying radon-induced carcinogenesis. Understanding these molecular mechanisms could ultimately improve early diagnostic methods and enhance therapy for cancers associated with radon exposure. Full article

Among the Central Asian countries, Kazakhstan is experiencing significant growth in uranium production and plays a key role in the mining industry. The aim of this study was to assess environmental gamma radiation levels and indoor radon concentrations in the settlements of Aqsu, Saumalkol, and Arykbalyk—situated in regions with a history of uranium mining activities—to evaluate potential radiation exposure risks to the local population. Measurements of ambient gamma radiation dose rates indicated that Saumalkol exhibited the highest variability, with recorded values reaching up to 0.56 ± 0.19 µSv/h, suggesting potential influence from abandoned mining areas. The equivalent equilibrium volume activity of radon revealed severe contamination in Aqsu (mean: 303 ± 57 Bq/m³, max: 4974 Bq/m³) and Saumalkol (mean: 658 ± 114 Bq/m³, max: 2470 Bq/m³). These findings underscore the need for immediate intervention measures such as improved ventilation and radon mitigation strategies to reduce exposure risks and protect residents from radiation-induced health hazards. This study presents a screening method to identify areas with potential radon risks. However, radon dose assessment requires long-term measurements for accurate evaluation of exposure levels and health risks, with extended monitoring needed for comprehensive assessment. Full article