Quantitative evaluation of anthropogenic sources and health risks of rare earth elements in airborne particulate matter.

Rare earth elements (REEs) have emerged as contaminants in airborne particulate matter (PM); however, their anthropogenic sources remain poorly quantified, and associated health risks are unknown. This study investigates the REE distribution across eight sizes of airborne PM during July and December in Qingdao, a major Chinese port city. Our results reveal a single coarse-mode distribution with REE concentrations. In contrast, fine PM (size: 0.43-2.1 µm) exhibits notable enrichment of La and Ce compared to Al and other REEs. This study traces La and Ce enrichment to fluid catalytic cracking catalysts (FCCC)-related sources, including refinery and ship emissions, by comparing the REE fractionation in samples with potential sources. We quantify the contributions from FCCC-related sources to La (July: 33.6 % ± 3.2 %, Dec.: 46.4 % ± 5.2 %) and Ce (July: 16.5 % ± 14.3 %, Dec.: 30.3 % ± 12.2 %) by comparing measured concentrations with predictions derived from neighboring REEs, a method previously used exclusively in aquatic systems. For the first time, supply ratios of refinery and ship to FCCC-related La are calculated using a two-component mixing model based on the [La]FCCC/[V]anth, revealing the dominance of refinery emissions (July: 97.3 % ± 0.6 %, Dec.: 99.6 % ± 0.1 %). Furthermore, a global review of La and Ce anomalies that integrates published REE data with our findings reveals a widespread distribution of positive anomalies. The significantly positive correlation between La and Ce anomalies underscores FCCC-related emissions as a global source in fine PM, contributing 0-92 % (mean: 35 % ± 33 %) for La and 0-72 % (mean: 21 % ± 24 %) for Ce. Although the non-carcinogenic health risks of Ce are generally low globally, concerns should be raised in areas near source emissions, where Ce health risks sharply increased along with its concentrations. There is urgently need to establish a threshold value for La, owing to its global enrichment. This study provides novel insights into the sources and health implications of REEs in airborne PM.

Radionuclides distribution and radiation hazards assessment of black sand separation plant's minerals: a case study.

This study assessed the radioactivity levels and associated risks in the black sand-separated products obtained from the black sand separation plant in Delta, Egypt. A total of sixteen samples were taken from hot spots during and after the separation process. These include water samples and other samples that represent monazite, rutile, zircon, granite, ilmenite, and silica products. The hot spots included the area where the ore was stored. The activity concentrations of 232 T h , 226 R a , and 40 K were determined in these samples using a p-type HPGe detector. Based on gamma spectrometric analysis, samples of rutile, zircon, and monazite had the highest amounts of radioactivity because they contained the highest NORM's activity concentrations. In addition, it indicated that the radiological hazard indices of the collected samples were higher than the average world limits for sand texture. These findings suggest that the black sand separation process reveals potential risks to human health and the environment, and therefore, appropriate measures need to be taken to mitigate these risks, especially for the safety of the workers on-site. Reducing the risk associated with those sites should be controlled by implementing the recommendations declared for the series of International Basic Safety Standards of the International Atomic Energy Agency (GSR) Part 3, as affirmed in Document No. 103 of 2007 by the International Commission on Radiological Protection (ICRP) as will be presented in the paper body.

Investigation of Rare Earth Element Binding to a Surface-Bound Affinity Peptide Derived from EF-Hand Loop I of Lanmodulin.

Bioinspired strategies have been given extensive attention for the recovery of rare earth elements (REEs) from waste streams because of their high selectivity, regeneration potential, and sustainability as well as low cost. Lanmodulin protein is an emerging biotechnology that is highly selective for REE binding. Mimicking lanmodulin with shorter peptides is advantageous because they are simpler and potentially easier to manipulate and optimize. Lanmodulin-derived peptides have been found to bind REEs, but their properties have not been explored when immobilized on solid substrates, which is required for many advanced separation technologies. Here, two peptides, LanM1 and scrambled LanM1, are designed from the EF-hand loop 1 of lanmodulin and investigated for their binding affinity toward different REEs when surface-bound. First, the ability of LanM1 to bind REEs was confirmed and characterized in solution using circular dichroism (CD), nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations for Ce(III) ions. Isothermal titration calorimetry (ITC) was used to further analyze the binding of the LanM1 to Ce(III), Nd(III), Eu(III), and Y(III) ions and in low-pH conditions. The performance of the immobilized peptides on a model gold surface was examined using a quartz crystal microbalance with dissipation (QCM-D). The studies show that the LanM1 peptide has a stronger REE binding affinity than that of scrambled LanM1 when in solution and when immobilized on a gold surface. QCM-D data were fit to the Langmuir adsorption model to estimate the surface-bound dissociation constant (Kd) of LanM1 with Ce(III) and Nd(III). The results indicate that LanM1 peptides maintain a high affinity for REEs when immobilized, and surface-bound LanM1 has no affinity for potential competitor calcium and copper ions. The utility of surface-bound LanM1 peptides was further demonstrated by immobilizing them to gold nanoparticles (GNPs) and capturing REEs from solution in experiments utilizing an Arsenazo III-based colorimetric dye displacement assay and ultraviolet-visible (UV-vis) spectrophotometry. The saturated adsorption capacity of GNPs was estimated to be around 3.5 µmol REE/g for Ce(III), Nd(III), Eu(III), and Y(III) ions, with no binding of non-REE Ca(II) ions observed.

Environmental and mineralogical studies on the stream sediments of Baltim-El Burullus coastal plain, North Delta, Egypt.

This work is mainly concerned with the effect of anthropogenic activities and natural radioactivity due to the presence of highly radioactive black sand spots, factory construction, and shipping, in addition to other activities like agriculture on human beings. Forty samples were collected along Baltim-El Burullus coastal plain to detect the effect of these problems and determine the suggested solutions. The black sand of the Baltim-El Burullus coastal plain exhibits a considerable amount of economically heavy minerals, their ratio relative to the bulk composition in the investigated samples ranges from 3.18 to 10.5% with an average of 5.45%. The most important of them are magnetite, ilmenite, rutile, leucoxene, garnet, zircon and monazite. The existence of some radioactive-bearing accessory mineral deposits like zircon and monazite led to measuring the naturally occurring radionuclides 226Ra, 232Th and 40K to evaluate the excess lifetime cancer risk (ELCR). The results showed that these concentrations are 19.1 ± 9.73, 14.7 ± 9.53 and 211 ± 71.34 Bq kg-1 were lower than the corresponding reported worldwide average of 35, 45, and 412 Bq kg-1 for each radionuclide (226Ra, 232Th, and 40 K). The gamma hazard indices such as absorbed dose rate (Dair), the annual effective dose (AED), and excess lifetime cancer risk (ELCR) factor were computed in the investigated sediments and all the results were found (Dair = 26.4 nGy h-1, AED = 0.03 mSv year-1, ELCR = 0.0001) to be lower than the values suggested by the United Nations Scientific Committee on the effect of Atomic Research (59 nGy h-1, 0.07 mSv year-1 and 0.0029 for Dair, AED and ELCR, respectively). The study suggests that the black sand is safe to use in various infrastructure applications at Baltim-El Burullus coastal plain. The levels of radioactivity are not high enough to pose a risk to human health.

What are exposure biomarkers of rare earth elements for the ionic rare earth occupational population?

Rare earth elements (REEs) are widely utilized in industries. However, The specific exposure features of REEs and potential biomarkers of exposure in occupational populations remain unclear. In this study, we evaluated the external and internal REEs exposure levels among the participants working in the ionic rare earth smelting plant. For the external exposure, the concentrations of 14 REEs and total rare earth elements (ΣREEs) in airborne particles were significantly elevated in the REEs-exposed versus non-exposed group (P < 0.05). Meanwhile, the levels of Yttrium (Y), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Thulium (Tm), Ytterbium (Yb), and ΣREEs in urine were higher in the REEs-exposed group compared to the non-exposed group (P < 0.05). Notably, a significant positive correlation was observed between Y in both the airborne particles and urine samples as well as Gd, and the Spearman correlation coefficient was 0.53 and 0.39 respectively, both P < 0.05. Conversely, no statistically significant differences were found in the levels of 15 REEs or ΣREEs in the blood samples between the REEs-exposed group and non-exposed group. Moreover, the concentrations of ΣREEs and 9 REEs in nail samples of the exposed group were significantly higher than those of the non-exposed group (P < 0.05), and the composition ratios of REEs in the nail samples closely resembled those found in individual airborne particles. Therefore, nail and urine samples were proposed to reflect long-term and short-term exposure to ionic rare earth respectively. Exposure biomarkers confirmed by external and internal exposure characteristics accurately provide the situation of human exposure to REEs environment, and have profound significance for monitoring and evaluating the level of REEs pollution in human body. It also provides a vital basis to find out the effect biomarkers, susceptible biomarkers and the health effects of rare earth environment for the future research.

Elevated levels of environmental radioactivity in fluvial sediment: origin and health risk assessment.

To study the geogenic processes of naturally occurring radioactive materials' (NORMs') distribution, a transboundary Himalayan river (Punarbhaba) is chosen due to its trivial anthropogenic impacts. In explaining the genesis of radionuclides, transition elements (Sc, Ti, V, and Fe), rare-earth-elements (REEs: La, Eu, Ce, Yb, Sm, and Lu), Ta, Hf, Th, and U were analysed in 30 riverbed sediments collected from the Bangladeshi portion of the river. Elemental abundances and NORMs' activity were measured by neutron activation analysis and HPGe-gamma-spectrometry, respectively. Averagen=30 radioactivity concentrations of 226Ra (68.4 Bq kg-1), 232Th (85.7 Bq kg-1), and 40K (918 Bq kg-1) were 2.0-2.3-fold higher, which show elevated results compared to the corresponding world mean values. Additionally, mean-REE abundances were 1.02-1.38-times higher than those of crustal origin. Elevated (relative to earth-crust) ratios of Th/U (=3.95 ± 1.84) and 232Th/40K and statistical demonstrations invoke Th-dominant heavy minerals, indicating the role of kaolinite clay mineral abundance/granitic presence. However, Th/Yb, La/V, Hf/Sc, and Th/Sc ratios reveal the presence of felsic abundances, hydrodynamic sorting, and recycling of sedimentary minerals. Geo-environmental indices demonstrated the enrichment of chemical elements in heavy minerals, whereas radiological indices presented ionizing radiation concerns, e.g., the average absorbed-gamma-dose rate (123.1 nGy h-1) was 2.24-fold higher compared to the threshold value which might cause chronic health impacts depending on the degree of exposure. The mean excess lifetime cancer risk value for carcinogen exposure was 5.29 × 10-4 S v-1, which is ∼2-times greater than the suggested threshold. Therefore, plausible extraction of heavy minerals and using residues as building materials can alleviate the two-reconciling problems: (1) radiological risk management and (2) fluvial navigability.

Fluorescence-Recovered Wearable Hydrogel Patch for In Vitro Detection of Glucose Based on Rare-Earth Nanoparticles.

The physiological state of the human body can be indicated by analyzing the composition of sweat. In this research, a fluorescence-recovered wearable hydrogel patch has been designed and realized which can noninvasively monitor the glucose concentration in human sweat. Rare-earth nanoparticles (RENPs) of NaGdF4 doped with different elements (Yb, Er, and Ce) are synthesized and optimized for better luminescence in the near-infrared second (NIR-II) and visible region. In addition, RENPs are coated with CoOOH of which the absorbance has an extensive peak in the visible and NIR regions. The concentration of H2O2 in the environment can be detected by the fluorescence recovery degree of CoOOH-modified RENPs based on the fluorescence resonance energy transfer effect. For in vivo detection, the physiological state of oxidative stress at tumor sites can be visualized through its fluorescence in NIR-II with low background noise and high penetration depth. For the in vitro detection, CoOOH-modified RENP and glucose oxidase (GOx) were doped into a polyacrylamide hydrogel, and a patch that can emit green upconversion fluorescence under a 980 nm laser was prepared. Compared with the conventional electrochemical detection method, the fluorescence we presented has higher sensitivity and linear detection region to detect the glucose. This improved anti-interference sweat patch that can work in the dark environment was obtained, and the physiological state of the human body is conveniently monitored, which provides a new facile and convenient method to monitor the sweat status.

Modulation of proteins by rare earth elements as a biotechnological tool.

Although rare earth element (REE) complexes are often utilized in bioimaging due to their photo- and redox stability, magnetic and optical characteristics, they are also applied for pharmaceutical applications due to their interaction with macromolecules namely proteins. The possible implications induced by REEs through modification in the function or regulatory activity of the proteins trigger a variety of applications for these elements in biomedicine and biotechnology. Lanthanide complexes have particularly been applied as anti-biofilm agents, cancer inhibitors, potential inflammation inhibitors, metabolic elicitors, and helper agents in the cultivation of unculturable strains, drug delivery, tissue engineering, photodynamic, and radiation therapy. This paper overviews emerging applications of REEs in biotechnology, especially in biomedical imaging, tumor diagnosis, and treatment along with their potential toxic effects. Although significant advances in applying REEs have been made, there is a lack of comprehensive studies to identify the potential of all REEs in biotechnology since only four elements, Eu, Ce, Gd, and La, among 17 REEs have been mostly investigated. However, in depth research on ecotoxicology, environmental behavior, and biological functions of REEs in the health and disease status of living organisms is required to fill the vital gaps in our understanding of REEs applications.

Identification of yttrium oxide-specific peptides for future recycling of rare earth elements from electronic scrap.

Yttrium is a heavy rare earth element (REE) that acquires remarkable characteristics when it is in oxide form and doped with other REEs. Owing to these characteristics Y2 O3 can be used in the manufacture of several products. However, a supply deficit of this mineral is expected in the coming years, contributing to its price fluctuation. Thus, developing an efficient, cost-effective, and eco-friendly process to recover Y2 O3 from secondary sources has become necessary. In this study, we used phage surface display to screen peptides with high specificity for Y2 O3 particles. After three rounds of enrichment, a phage expressing the peptide TRTGCHVPRCNTLS (DM39) from the random pVIII phage peptide library Cys4 was found to bind specifically to Y2 O3 , being 531.6-fold more efficient than the wild-type phage. The phage DM39 contains two arginines in the polar side chains, which may have contributed to the interaction between the mineral targets. Immunofluorescence assays identified that the peptide's affinity was strong for Y2 O3 and negligible to LaPO4 :Ce3+ ,Tb3+ . The identification of a peptide with high specificity and affinity for Y2 O3 provides a potentially new strategic approach to recycle this type of material from secondary sources, especially from electronic scrap.

Associations of maternal urinary rare earth elements individually and in mixtures with neonatal size at birth.

Prenatal rare earth elements (REEs) exposure is linked to unfavorable health consequences. Epidemiologic research on repeated measurements of REEs during gestation correlated with fetal growth is exiguous. Until now, few studies have characterized exposure characteristics of REEs in pregnant women. We aimed to ascertain the characteristics and predictors of REEs exposure over three trimesters among pregnant women and examine the possible effects of prenatal REEs exposure on size at birth. Urinary REEs concentrations exhibited considerable within-subject variation with intraclass correlation coefficients ranging from 0.16 to 0.58. Maternal age, household income, gestational weight gain, passive smoking during pregnancy, parity, and neonatal gender were associated with maternal urinary REEs concentrations. Elevated maternal urinary holmium and thulium concentrations in the 3rd trimester were significantly related to reductions in birth weight. Weighted quantile sum (WQS) regression model identified that urinary REEs mixture in the 3rd trimester were negatively related to birth weight (WQSREEs ß = -26.22; 95% confidence interval [CI]: -47.62, -4.82), with holmium (40%) and thulium (24%) receiving the highest weights. Male infants received the most weight (>50%) related to decreased birth weight. This study revealed a significant association between individual and mixture REE exposure in late pregnancy with a reduction in birth weight.

Scalable and Consolidated Microbial Platform for Rare Earth Element Leaching and Recovery from Waste Sources.

Chemical methods for the extraction and refinement of technologically critical rare earth elements (REEs) are energy-intensive, hazardous, and environmentally destructive. Current biobased extraction systems rely on extremophilic organisms and generate many of the same detrimental effects as chemical methodologies. The mesophilic methylotrophic bacterium Methylobacterium extorquens AM1 was previously shown to grow using electronic waste by naturally acquiring REEs to power methanol metabolism. Here we show that growth using electronic waste as a sole REE source is scalable up to 10 L with consistent metal yields without the use of harsh acids or high temperatures. The addition of organic acids increases REE leaching in a nonspecific manner. REE-specific bioleaching can be engineered through the overproduction of REE-binding ligands (called lanthanophores) and pyrroloquinoline quinone. REE bioaccumulation increases with the leachate concentration and is highly specific. REEs are stored intracellularly in polyphosphate granules, and genetic engineering to eliminate exopolyphosphatase activity increases metal accumulation, confirming the link between phosphate metabolism and biological REE use. Finally, we report the innate ability of M. extorquens to grow using other complex REE sources, including pulverized smartphones, demonstrating the flexibility and potential for use as a recovery platform for these critical metals.

A NIR Programmable In Vivo miRNA Magnifier for NIR-II Imaging of Early Stage Cancer.

Aberrant expressions of biomolecules occur much earlier than tumor visualized size and morphology change, but their common measurement strategies such as biopsy suffer from invasive sampling process. In vivo imaging of slight biomolecule expression difference is urgently needed for early cancer detection. Fluorescence of rare earth nanoparticles (RENPs) in second near-infrared (NIR-II) region makes them appropriate tool for in vivo imaging. However, the incapacity to couple with signal amplification strategies, especially programmable signal amplification strategies, limited their application in lowly expressed biomarkers imaging. Here we develop a 980/808 nm NIR programmed in vivo microRNAs (miRNAs) magnifier by conjugating activatable DNAzyme walker set to RENPs, which achieves more effective NIR-II imaging of early stage tumor than size monitoring imaging technique. Dye FD1080 (FD1080) modified substrate DNA quenches NIR-II downconversion emission of RENPs under 808 nm excitation. The miRNA recognition region in DNAzyme walker is sealed by a photo-cleavable strand to avoid "false positive" signal in systemic circulation. Upconversion emission of RENPs under 980 nm irradiation activates DNAzyme walker for miRNA recognition and amplifies NIR-II fluorescence recovery of RENPs via DNAzyme catalytic reaction to achieve in vivo miRNA imaging. This strategy demonstrates good application potential in the field of early cancer detection.

Noninvasive In Vivo Imaging of T-Cells during Cancer Immunotherapy Using Rare-Earth Nanoparticles.

Only a minority of patients respond positively to cancer immunotherapy, and addressing this variability is an active area of immunotherapy research. Infiltration of tumors by immune cells is one of the most significant prognostic indicators of response and disease-free survival. However, the ability to noninvasively sample the tumor microenvironment for immune cells remains limited. Imaging in the near-infrared-II region using rare-earth nanocrystals is emerging as a powerful imaging tool for high-resolution deep-tissue imaging. In this paper, we demonstrate that these nanoparticles can be used for noninvasive in vivo imaging of tumor-infiltrating T-cells in a highly aggressive melanoma tumor model. We present nanoparticle synthesis and surface modification strategies for the generation of small, ultrabright, and biocompatible rare-earth nanocrystals necessary for deep tissue imaging of rare cell types. The ability to noninvasively monitor the immune contexture of a tumor during immunotherapy could lead to early identification of nonresponding patients in real time, leading to earlier interventions and better outcomes.

Improved recovery selectivity of rare earth elements from mining wastewater utilizing phytosynthesized iron nanoparticles.

While rare earth elements (REEs) play key roles in many modern technologies, the selectivity of recovering of REEs from mining wastewater remains a critical problem. In this study, iron nanoparticles (FeNPs) synthesized from euphorbia cochinchinensis extracts were successfully used for selective recovery of REEs from real mining wastewater with removal efficiencies of 89.4% for Y(III), 79.8% for Ce(III) and only 6.15% for Zn(Ⅱ). FTIR and XPS analysis suggested that the high selective removal efficiency of Y(III) and Ce(III) relative to Zn(Ⅱ) on FeNPs was due to a combination of selective REEs adsorption via complexing with O or N, ion exchange with H+ present in functional groups contained within the capping layer and electrostatic interactions. Adsorptions of Y(III) and Ce(III) on FeNPs conformed to pseudo second-order kinetics and the Langmuir isotherm model with maximum adsorption capacities of 5.10 and 0.695 mg∙g-1, respectively. The desorption efficiencies of Y(III) and Ce(III) were, respectively, 95.0 and 97.9% in 0.05 M acetic acid, where desorption involved competitive ion exchange between Y(III), Ce(III) and Zn(Ⅱ) with H+ contained in acetic acid and intraparticle diffusion. After four consecutive adsorption-desorption cycles, adsorption efficiencies for Y(III) and Ce(III) remained relatively high at 52.7% and 50.1%, respectively, while desorption efficiencies of Y(III) and Ce(III) were > 80.0% and 95.0%, respectively. Overall, excellent reusability suggests that FeNPs can practically serve as a potential high-quality selectivity material for recovering REEs from mining wastewaters.

Innovative lanthanide complexes: Shaping the future of cancer/ tumor chemotherapy.

Developing new therapeutic and diagnostic metals and metal complexes is a stunning example of how inorganic chemistry is rapidly becoming an essential part of modern medicine. More study of bio-coordination chemistry is needed to improve the design of compounds with fewer harmful side effects. Metal-containing drugs are widely utilized in the treatment of cancer. Platinum complexes are effective against some cancers, but new coordination compounds are being created with improved pharmacological properties and a broader spectrum of anticancer action. The coordination complexes of the 15 lanthanides or rare earth elements in the periodic table are crucial for diagnosing and treating cancer. Understanding and treating cancer requires the detection of binding lanthanide (III) ions or complexes to DNA and breaking DNA by these complexes. Current advances in lanthanide-based coordination complexes as anticancer treatments over the past five years are discussed in this study.

A double rare earth doped CD nanoplatform for nanocatalytic/starving-like synergistic therapy with GSH-depletion and enhanced reactive oxygen species generation.

Cancer has been one of the principal diseases threatening human health in the world. Traditional chemotherapy, radiotherapy and surgery in clinical applications have some disadvantages, such as inefficiency, low specificity, and serious side effects. Therefore, some emerging synergistic therapies have been developed for more accurate diagnosis and more efficient treatment of cancer. Herein, novel Ce-Gd@CDs-GOx nanozymes were obtained by combining magnetic resonance/fluorescence (MR/FL) imaging and nanocatalytic/starving-like synergistic therapy for tumor tissue imaging and efficient cancer treatment. The as-prepared Ce-Gd@CDs-GOx nanozymes with a diameter of 25.0 ± 0.8 nm exhibited favorable physiological stability, negligible toxicity, bright fluorescence and strong T1-weighted MR imaging (MRI) performance (10.97 mM-1 s-1). Moreover, the nanozymes could not only cut off the nutrient supply of tumor cells, but also generate ROS to synergistically enhance antitumor efficacy. The coexistence of Ce3+/Ce4+ in Ce-Gd@CDs-GOx endowed them with attractive capacity for alleviating hypoxia and enhancing GSH consumption to induce the apoptosis of tumor cells. Furthermore, most of the 4T1 cells treated with Ce-Gd@CDs-GOx nanozymes were damaged in the CCK-8 and Calcein-AM/PI staining assays, indicating the excellent efficiency of intracellular synergistic therapy. In summary, this study offered a promising strategy to design a nanoplatform for MR/FL imaging-guided nanocatalytic and starvation-like synergistic therapy of cancer.

The development of rare-earth combined Fe-based magnetic nanocomposites for use in biological theranostics.

Iron (Fe)-based nanoparticles (NPs) represented by Fe3O4 exhibit attractive properties, such as high saturation magnetization, low magneto-crystalline anisotropy, and good biocompatibility, and are useful as magnetic resonance imaging (MRI) contrast agents. However, the existence of artifacts makes the single magnetic resonance imaging mode lack accuracy in tumor diagnosis. To overcome this limitation, a strategy where rare-earth elements are combined with Fe-based NPs is applied. Rare earth is the general name of Sc, Y, and elements with unique 4f electronic configurations. Some rare-earth elements like Gd and Lu exhibit magnetic properties due to unpaired electrons, while some, like Er and Ho, fluoresce under excitation ascribed to the electron transition at intermediate energy levels. In this manuscript, attention is focused on multimodal nanomaterials composed of rare-earth elements and Fe-based NPs. We provide an overview of the synthetic routes and current biomedical application of the nanocomposites that show potential for precise diagnosis and efficient treatment of cancers.

The role of rare earth elements and dietary intake in tongue cancer: a mediation analysis in southeast China.

Objective: The current research aimed to examine how dietary intake and rare earth elements may affect the development of tongue cancer. Methods: The serum levels of 10 rare earth elements (REEs) in 171 cases and 171 healthy matched controls were measured by inductively coupled plasma mass spectrometry (ICP-MS). The conditional logistic regression was used to examine the relationship between dietary intake, serum levels of 10 REEs, and tongue cancer. Mediation effect and multiplicative interaction analysis were then performed to estimate the potential contribution of REEs in dietary intake associated with tongue cancer. Results: Compared with the control group, patients with tongue cancer consumed significantly less fish, seafood, fruit, green leafy vegetables, and non-green leafy vegetables, with higher serum praseodymium (Pr), dysprosium (Dy), and lanthanum (La) levels, and lower serum cerium (Ce) and scandium (Sc) levels. The interaction effect was observed between some REEs and food categories. Green vegetables' impact on the risk of tongue cancer is partially attributed to the La and Thorium (Th) elements (P < 0.05, the mediated proportion were 14.933% and 25.280%, respectively). The effect of non-green leafy vegetables for tongue cancer mediated via Pr, Dy, and Th (P < 0.05, the mediated proportion were 0.408%, 12.010%, and 8.969%, respectively), and the Sc components in seafood (P < 0.05, the mediated proportion was 26.120%) is partly responsible for their influence on the risk of tongue cancer. Conclusion: The correlation between REEs and dietary intakes for tongue cancer is compact but intricate. Some REEs interact with food intake to influence tongue cancer, while others act as a mediator.

Variation of sulfate reducing bacteria communities in ionic rare earth tailings and the potential of a single cadmium resistant strain in bioremediation.

Heap leaching ionic rare earth tailings might be prone to nourish sulfate reducing bacteria (SRB), but the SRB community in terrestrial ecosystems, such as tailings, has never been studied. This work was conducted to investigate the SRB communities in revegetated and bare tailings in Dingnan county, Jiangxi province, China, incorporating with indoor experiments to isolate SRB strain in bioremediation of Cd contamination. Significant increases in richness, accompanied by reductions in evenness and diversity, were found in the SRB community in revegetated tailings compared to bare tailings. At genus taxonomic level, two distinct dominant SRB were observed in samples from bare and revegetated tailings, with Desulfovibrio dominating in the former and Streptomyces dominating in the latter, respectively. A single SRB strain was screened out from the bare tailings (REO-01). The cell of REO-01 was rod-shaped and belonged to family Desulfuricans and genus Desulfovibrio. The Cd resistance of the strain was further examined, no changes in cell morphology were observed at 0.05 mM Cd, additionally, the atomic ratios of S, Cd, and Fe changed with the increase in Cd dosages, indicating FeS and CdS were produced simultaneously, XRD results further confirmed the production changed gradually from FeS to CdS with increasing Cd dosages from 0.05 to 0.2 mM. FT-IR analysis showed that functional groups containing amide, polysaccharide glycosidic linkage, hydroxyl, carboxy, methyl, phosphodiesters and sulfhydryl groups in extracellular polymeric substances (EPS) of REO-01 might have affinity with Cd. This study demonstrated the potential of a single SRB strain isolated from ionic rare earth tailings in bioremediation of Cd contamination.

[The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice].

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1ß (IL-1ß), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1ß and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.