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Gas chromatography-mass spectrometry (GC-MS) has been applied to the analysis of arsenic forms in water, plants, and other samples; however, it has not been used to determine the form of arsenic in soil due to the complex soil matrix. The purpose of this study was to develop an analytical method for the simultaneous determination of inorganic arsenic species (As (III) and As (V)) and monomethylarsonic acid (MMA) in soil using GC-MS. The arsenic compounds were subjected to derivatization with 2,3-dimercapto-1-propanol (BAL) and subsequently analyzed using GC-MS. The BAL volume, derivatization reaction time, and temperature were optimized using standard added soil extracts. A reaction with 150 μL of BAL at 40°C for 30 min was selected as the optimal condition for quantitative derivatization of both inorganic arsenic (iAs) and MMA. The calibration curves exhibited linearity within the range of 5–100 ng/mL for each arsenic species, with correlation coefficients exceeding 0.997. The limits of detection for each arsenic species were determined to be 0.24 ng/mL and 1.31 ng/mL, respectively. The accuracy of the method was verified by the recovery of reference samples. The recovery experiments for reference samples showed that the recovery rates for As (III), As (V), and MMA were 89.5–93.7%, 88.5–105.6%, and 90.2–95.8% respectively, with precision ranging from 4.6 to 6.5%, 2.3 to 3.8%, and 2.4 to 6.3%. These results indicate good accuracy and precision. The accuracy of this method is not significantly different from that of liquid chromatography-inductively coupled plasma mass spectrometry (p = 0.05). The optimized method was sensitive, convenient and reliable for the extraction and analysis of different arsenic species in soil samples. [ABSTRACT FROM AUTHOR]

People are paying more and more attention to the effects of environmental factors such as heavy metals on depression, and heavy metals may destroy the homeostasis of vitamin D in the body by affecting human metabolism, and the lack of vitamin D will increase the risk of depression. There are few studies on vitamin D deficiency in depression caused by heavy metals, and it is not deep enough. Therefore, this study used logistic regression, restricted cubic spline curve, weighted quantile and Quantile g-computation model to analyze the effects of heavy metal exposure alone and in combination on vitamin D and depression, as well as the potential role of vitamin D deficiency in the process of heavy metal-induced depression. The results showed that cadmium exposure alone or in combination increased the risk of depression (P < 0.05). When Cd increased by 1 unit, the risk of depressive symptoms increased by 1.178 units. Arsenic and its compounds and lead affected vitamin D levels in the body and contributed the second highest or highest weight in the mixture (P < 0.05). It is worth noting that after grouping according to vitamin D deficiency, compared with the normal group, the mixed exposure of heavy metals in the vitamin D deficiency group had more types of metals related to depression and contributed more weight (P < 0.05). This study found that single metal or multi-metal mixed exposure is associated with depression. Vitamin D deficiency may increase the risk of depression. Vitamin D may be a potential factor in the treatment of depression caused by metal, and the specific mechanism of action needs further study. • The study evaluated the correlation between single metal and its mixture exposure and depression and vitamin D deficiency. • Multiple models were used to analyze the correlation between metal exposure and depression and vitamin D deficiency. • Vitamin D deficiency may aggravate depression caused by metal exposure. [ABSTRACT FROM AUTHOR]

Arsenic trioxide (ATO) has been shown to inhibit pancreatic cancer (PC) cell growth in vitro and to promote the inhibitory effects of gemcitabine (Gem) on PC in vivo. However, the high toxicity of ATO associated with the required high doses and indiscriminate targeting has limited its clinical application. This study aimed to determine whether coupling arsenic to a tumor homing peptide would increase the inhibitory potency against PC cells. The effects of this peptide-linked arsenic compound (PhAs-LHP), the analogous non-targeting arsenic compound (phenylarsine oxide, PAO), and marketed ATO on PC growth were tested in vitro and in a mouse model. The data demonstrated that PhAs-LHP inhibited PC cell growth in vitro more potently, with IC50 values 10 times lower than ATO. Like ATO, PhAs-LHP induced cell death and cell cycle arrest. This cytotoxic effect of PhAs-LHP was mediated via a macropinocytosis-linked uptake pathway as amiloride (a macropinocytosis inhibitor) reduced the inhibitory effect of PhAs-LHP. More importantly, PhAs-LHP inhibited PC growth in mice and enhanced the inhibitory effect of Gem on PC growth at 2 times lower molar concentration than PAO. These results indicate that PhAs-LHP inhibited PC more potently than ATO/PAO and suggest a potential clinical use for the combination of Gem with the peptide-linked arsenic compound for the treatment of pancreatic cancer. [ABSTRACT FROM AUTHOR]

The mobility of arsenic compounds in the soil-plant system and its interaction with biogenic macroelements K, P, Ca, Mg, Si, S, Na in plants under conditions of toxic stress have been studied. This is illustrated by the wheatgrass Elytrigia repens. It has been established that the root system is responsible for protecting the aerial part of wheatgrass from excess arsenic, and it is of great importance for phytostabilisation of arsenic pollution therefore indicating the increased tolerance of this plant. The intensity of As accumulation in plants depends on its speciation in the soil. Antagonism of the main essential elements (K, P) to the accumulation of As in wheatgrass shoots is observed. It can lead to disruption of metabolic processes in plant cells. It has been shown that changes in the K+/Na + values may lead to violation of osmotic processes in the aerial plant organs and contribute to their degradation not only under salt stress but also under the influence of higher concentrations of As in the plants. In areas intensively contaminated with arsenic, a decrease in the K/Na value in the above-ground organs of wheatgrass can be used as a criterion for the degree of phytotoxicity. [ABSTRACT FROM AUTHOR]

Simple Summary: Relapses of acute promyelocytic leukemia (APL) remain a challenge despite the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Given the variability in salvage therapies and emerging evidence supporting the deferral of hematopoietic cell transplantation (HCT) in patients receiving ATO, we analyzed the outcomes of a multicentric cohort of 67 relapsed APL patients. Better outcomes were reported with ATO ± ATRA compared to chemo-based regimens and ATRA ± Gemtuzumab ozogamicin (GO). A significant survival advantage was observed for patients undergoing HCT in the chemo-based cohort (p = 0.017), but not in the ATO-based group (p = 0.12). Achieving molecular complete remission (CR) post salvage therapy emerged as the main prognostic factor for second relapses in both univariate and multivariate analyses. Our findings support the efficacy of ATO-based therapies in first relapse and enhance the role of molecular remission as an independent outcome predictor in both first and second APL relapses. Background: The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has radically improved the prognosis of acute promyelocytic leukemia (APL), with cure rates above 80%. While relapse occurs in less than 20% of cases, addressing this issue remains challenging. Identifying effective salvage therapies for relapsed APL is crucial to improve patient outcomes. Methods: A retrospective analysis was performed on a multicentric cohort of 67 APL patients in first relapse, treated in three Italian hematology centers from June 1981 to November 2021. The overall survival (OS) and cumulative incidence of relapse (CIR) were calculated, and predictive factors were assessed using Cox regression models. Results: Overall, 61 patients (91%) received ATO ± ATRA (40.3%), chemo-based regimens (40.3%), or ATRA ± Gemtuzumab ozogamicin (GO) (10.4%). Complete remission (CR) was achieved in 98.2% of patients (molecular CR, n = 71.4%). With a median follow-up time of 54.5 months, the 5-year OS was 73% in the ATO ± ATRA group, 44% in the chemo-based group, and 29% in the ATRA ± GO group (p = 0.035). The 5-year OS rate was also higher for transplant recipients vs. non-recipients within the chemo-based cohort (50% vs. 33%, p = 0.017), but not in the ATO-based cohort (p = 0.12). ATO-based salvage therapy resulted in better OS in both univariate (p = 0.025) and multivariate analyses (p = 0.026). The 2-year CIR was higher in patients without molecular CR vs. patients in molecular CR (66% vs. 24%, p = 0.034). Molecular CR was a significant predictor of second relapse in both univariate (p = 0.035) and multivariate analyses (p = 0.036). Conclusions: Our findings support the efficacy of ATO-based therapies in first relapse of APL and confirm the achievement of molecular remission as an independent outcome predictor in both first and second APL relapse. [ABSTRACT FROM AUTHOR]

We report the synthesis of arsenic heterocycles derived from saccharides 2–4 and AsCl3. Compounds 5 and 6 are stable in aqueous solutions, DMSO, or methanolic solutions. However, NMR and HPLC studies revealed that intramolecular trans‐esterification processes leads to dynamic equilibria. Theoretical studies revealed that three arsenates and two arsoranes participate in these intramolecular equilibria and account for the experimental spectroscopy and HPLC results. Through the correlation between the experimental and theoretical 13C NMR spectra, we proposed the speciation of arsenic Compounds 5 and 6. Moreover, experimental and theoretical IR spectra demonstrated that arsenates 5 A and 6 A predominate in the solid state. QTAIM studies were performed to explain the chemical shifts in the 13C NMR spectra. Biological studies suggest that the structural flexibility of Compounds 5 and 6 increase the cytotoxic and antiproliferative activities of these compounds. [ABSTRACT FROM AUTHOR]

In many places in the world, groundwater contains arsenic compounds. To purify water containing arsenic effectively, arsenic (III) compounds must be oxidised. The subject of this study is oxidation of arsenic (III) compounds in an aqueous solution in a flow column mode. The industrial arsenic oxidation technology involving aggressive oxidising agents such as chlorine or ozone, which is used most commonly today, has a number of serious disadvantages. The most problematic include extremely high risks for human health and the environment, the process cost and overall complexity. Catalytic oxidation of arsenic (III) compounds with atmospheric oxygen is an alternative that is free from the above disadvantages. Previously, the author studied the process of effective catalytic oxidation of arsenic (III) on the new active manganese dioxide (NADM) he had synthesised. Later, however, it turned out that NADM has a significant drawback: during prolonged flow column stops, its catalytic activity drops sharply. This work proposes both a theoretical justification for and a solution to this problem. A new calcium-doped active manganese dioxide NADM-Ca0.5 was synthesised. It was shown that NADM-Ca0.5 demonstrates high catalytic activity towards arsenic (III). The fact that flow column long stops do not affect its catalytic activity was also experimentally confirmed. On the basis of the study results, some theoretical aspects are also discussed of the mechanism for catalytic oxidation of arsenic (III) with oxygen on active manganese dioxide in an aqueous solution. For successful industrial implementation of the technology for catalytic oxidation of arsenic (III) compounds on NADM-Ca0.5, experimental work on pilot plants in the field is required and further laboratory research is needed in order to develop a detailed theoretical basis for the mechanism of catalytic oxidation of arsenic in aqueous solutions. The results of this work are of interest for both industrial companies specialising in water purification from arsenic compounds, and scientists and researchers studying catalytic oxidation of arsenic (III), as well as heterogeneous catalytic oxidation with oxygen in general. [ABSTRACT FROM AUTHOR]

We synthesized arsenic analogs of a tridentate PPP ligand, bis[2‐(diphenylphosphino) phenyl] phenylphosphine, achieving yields of 40 % to 71 %. Additionally, we prepared copper (I) halide (CuX, X=Br, I) complexes with these ligands, with yields between 43 % and 84 %. Using both experimental and computational methods, we examined their structures and photophysical characteristics. Single crystal X‐ray diffraction showed that all eight complexes had distorted tetrahedral geometries. These complexes exhibited photoluminescence with emission bands peaking from 506 nm to 551 nm and quantum yields up to 0.92 at room temperature. Emission lifetimes varied and showed no direct correlation with quantum yields or wavelengths. Physical manipulation and solvent variations significantly altered their photoluminescent properties. DFT and TD‐DFT calculations revealed that higher arsenic content increased spin‐orbit coupling constants, with iodide complexes performing better than bromide ones due to heavier elements enhancing spin‐orbit coupling. Substituting phosphorus with arsenic significantly affected the luminescence quantum yield and lifetime, demonstrating the heavy‐atom effect of arsenic. The position of arsenic in the ligands critically influenced the photophysical outcomes of the CuX complexes. [ABSTRACT FROM AUTHOR]

Arsenic is highly toxic to the human bladder. In the present study, we established a human bladder epithelial cell line that closely mimics normal human bladder epithelial cells by immortalizing primary uroplakin 1B-positive human bladder epithelial cells with human telomerase reverse transcriptase (HBladEC-T). The uroplakin 1B-positive human bladder epithelial cell line was then used to evaluate the toxicity of seven arsenicals (iAsV, iAsIII, MMAV, MMAIII, DMAV, DMAIII, and DMMTAV). The cellular uptake and metabolism of each arsenical was different. Trivalent arsenicals and DMMTAV exhibited higher cellular uptake than pentavalent arsenicals. Except for MMAV, arsenicals were transported into cells by aquaglyceroporin 9 (AQP9). In addition to AQP9, DMAIII and DMMTAV were also taken up by glucose transporter 5. Microarray analysis demonstrated that arsenical treatment commonly activated the NRF2-mediated oxidative stress response pathway. ROS production increased with all arsenicals, except for MMAV. The activating transcription factor 3 (ATF3) was commonly upregulated in response to oxidative stress in HBladEC-T cells: ATF3 is an important regulator of necroptosis, which is crucial in arsenical-induced bladder carcinogenesis. Inorganic arsenics induced apoptosis while MMAV and DMAIII induced necroptosis. MMAIII, DMAV, and DMMTAV induced both cell death pathways. In summary, MMAIII exhibited the strongest cytotoxicity, followed by DMMTAV, iAsIII, DMAIII, iAsV, DMAV, and MMAV. The cytotoxicity of the tested arsenicals on HBladEC-T cells correlated with their cellular uptake and ROS generation. The ROS/NRF2/ATF3/CHOP signaling pathway emerged as a common mechanism mediating the cytotoxicity and carcinogenicity of arsenicals in HBladEC-T cells. [ABSTRACT FROM AUTHOR]

From at least the fifteenth to late nineteenth centuries, peasants in the Austrian province of Styria ate up to several hundred milligrams of arsenic trioxide or sulfide daily or weekly for periods up to a number of years. Taking these doses of arsenic was believed to increase muscular power and enhance the beauty and sexual attractiveness of peasant girls. There do not appear to be contemporaneous records of the known consequences of chronic arsenic exposure. The historical records of arsenic eating there are reviewed and appear to be valid. The benefits are subjective judgements by arsenic eaters. The lack of objective reports of the anticipated external and internal clinical and pathological effects of arsenic poisoning depends on a smaller number of clinical accounts and autopsy reports and the general medical literature of those times, so it is weaker, but it is consistent. Why the arsenic eaters did not show the well-known consequences of prolonged exposure to high doses of arsenic is not known. Possible explanations include increases in detoxifying metabolism in the consumers due to induced genomic changes and selection in people and in the gut microbiome, as shown in other populations. Whether these effects would suffice to protect people against their high doses of arsenic has not been explored. Although the nature and mechanisms of arsenic toxicity have been extensively described, much still remains to be discovered. [ABSTRACT FROM AUTHOR]

Inorganic arsenic species exist in the environment as a result of both natural sources, such as volcanic and geothermal activities, and geological formations, as well as anthropogenic activities, including smelting, exploration of fossil fuels, coal burning, mining, and the use of pesticides. These species deposit in water, rocks, soil, sediments, and the atmosphere. Arsenic-contaminated drinking water is a global public health issue because of its natural prevalence and toxicity. Therefore, chronic exposure to arsenic can have deleterious effect on humans, including cancer and other diseases. This work describes the mechanisms of environmental exposure to arsenic, molecular regulatory factors involved in its metabolism, genetic polymorphisms affecting individual susceptibility and the toxic effects of arsenic on human health (oxidative stress, DNA damage and cancer). We conclude that the role of single nucleotide variants affecting urinary excretion of arsenic metabolites are highly relevant and can be used as biomarkers of the intracellular retention rates of arsenic, showing new avenues of research in this field. • Inorganic arsenic exposure and its impact on the human health. • Genetic polymorphisms and it role on urinary excretion of arsenic metabolites. • Susceptibility and potential risk of toxic effects by ingestion of inorganic arsenic. [ABSTRACT FROM AUTHOR]

Arsenic is one of the most toxic elements present in the environment, especially in water. The World Health Organization (WHO) recommends a maximum concentration of arsenic in drinkable water of 10 μg/l (10 ppb). Sensors implementing Surface Enhanced Raman Scattering (SERS) can detect chemical species at low concentrations. The aim of this study is to compare two kinds of silver-coated SERS substrates for detection and speciation of trace, trivalent and pentavalent, inorganic arsenic compounds. One type of substrate was prepared by a classical thermal evaporation technique, and the second type by an electroless process. The thermally evaporated substrates allowed the detection of As(III) only, at a limit of detection (LOD) of approximately 50 mg/l, whereas As(V) could not be detected at any analyte concentration. The electroless substrates allow one to differentiate As(III) and As(V) with a LOD 1 μg/l (1 ppb) equal for each valency, below the WHO recommendation. The electroless substrates show a very large sensitivity across up to five orders of magnitude in terms of analyte concentration. Although the SERS intensity shows a nonlinear behavior over this range of concentrations, these preliminary results are encouraging in the framework of the demonstration of trace As SERS sensors in drinkable water. [ABSTRACT FROM AUTHOR]

A liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source operating at a nominal power of 30 W and solution flow rate of 30 µL min−1 and supported in a He sheath gas flow rate of 500 mL min−1 was interfaced to an Orbitrap mass spectrometer and assessed for use in rapid identification of inorganic and organic arsenic species, including As(III), As(V), monomethylarsonic acid, dimethylarsinic acid, and arsenobetaine in a 2% (v/v) nitric acid medium. Mass spectral acquisition in low-resolution mode, using only the ion trap analyzer, provided detection of protonated molecular ions for AsBet (m/z 179), DMA (m/z 139), MMA (m/z 141), and As(V) (m/z 143). As(III) is oxidized to As(V), likely due to in-source processes. Typical fragmentation of these compounds resulted in the loss of either water or methyl groups, as appropriate, i.e., introducing DMA also generated ions corresponding to MMA and As(V) as dissociation products. Structure assignments were also confirmed by high-resolution Orbitrap measurements. Spectral fingerprint assignments were based on the introduction of solutions containing 5 µg mL−1 of each arsenic compound. [ABSTRACT FROM AUTHOR]

Organic arsenic compounds such as p-aminophenylarsine oxide (p-APAO) are easier for structural optimization to improve drug-like properties such as pharmacokinetic properties, therapeutic efficacy, and target selectivity. In order to strengthen the selectivity of 4-(1,3,2-dithiarsinan-2-yl) aniline 7 to tumor cell, a thiourea moiety was used to strengthen the anticancer activity. To avoid forming a mixture of α/β anomers, the strategy of 2-acetyl's neighboring group participation was used to lock the configuration of 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate from 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide. 1-(4-(1,3,2-dithiarsinan-2-yl) aniline)-2-N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranos-1-yl)-thiourea 2 can increase the selectivity of human colon cancer cells HCT-116 (0.82 ± 0.06 μM vs. 1.82 ± 0.07 μM) to human embryonic kidney 293T cells (1.38 ± 0.01 μM vs. 1.22 ± 0.06 μM) from 0.67 to 1.68, suggesting a feasible approach to improve the therapeutic index of arsenic-containing compounds as chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Exposure to inorganic arsenic (As) is recognized as a risk factor for non-melanoma skin cancer (NMSC). We followed up with 7000 adults for 6 years who were exposed to As. During follow-up, 2.2% of the males and 1.3% of the females developed basal cell carcinoma (BCC), while 0.4% of the male and 0.2% of the female participants developed squamous cell carcinoma (SCC). Using a panel of more than 400 cancer-related genes, we detected somatic mutations (SMs) in the first 32 NMSC samples (BCC = 26 and SCC = 6) by comparing paired (tissue–blood) samples from the same individual and then comparing them to the SM in healthy skin tissue from 16 participants. We identified (a) a list of NMSC-associated SMs, (b) SMs present in both NMSC and healthy skin, and (c) SMs found only in healthy skin. We also demonstrate that the presence of non-synonymous SMs in the top mutated genes (like PTCH1, NOTCH1, SYNE1, PKHD1 in BCC and TP53 in SCC) significantly affects the magnitude of differential expressions of major genes and gene pathways (basal cell carcinoma pathways, NOTCH signaling, IL-17 signaling, p53 signaling, Wnt signaling pathway). These findings may help select groups of patients for targeted therapy, like hedgehog signaling inhibitors, IL17 inhibitors, etc., in the future. [ABSTRACT FROM AUTHOR]

Observation of arsenic water treatment adsorption media in the treated water of several homes with high arsenic private wells led to the hypothesis that treatment media was escaping the treatment systems and entering the plumbing and drinking water. Our research at 62 homes identified that microparticles of arsenic water treatment media and/or water softener resin had escaped the treatment system in 71% of the homes. This is a potential health hazard as ingesting arsenic treatment media or water softener resin may lead to an elevated ingestion exposure to arsenic and other contaminants. Potential causes of media escape from the treatment systems include media observed to be smaller in size than specifications and media breaking into smaller pieces. One interim solution to media escape is installation of a post‐treatment sediment filter. New developments in media durability or treatment system design and maintenance may be needed to prevent media escaping into drinking water. Practitioner Points: Arsenic in private wells is often treated with point‐of‐entry whole house adsorption systems.Arsenic adsorption treatment media and/or water softener resin was observed in treated water at 44 of 62 homes inspected.Water treatment media escaping into treated water is a potential hazardous exposure pathway.Potential causes and solutions are discussed. [ABSTRACT FROM AUTHOR]

The global concern over arsenic contamination in water due to its natural occurrence and human activities has led to the development of innovative solutions for its detection and remediation. Microbial metabolism and mobilization play crucial roles in the global cycle of arsenic. Many microbial arsenic-resistance systems, especially the ars operons, prevalent in bacterial plasmids and genomes, play vital roles in arsenic resistance and are utilized as templates for designing synthetic bacteria. This review novelty focuses on the use of these tailored bacteria, engineered with ars operons, for arsenic biosensing and bioremediation. We discuss the advantages and disadvantages of using synthetic bacteria in arsenic pollution treatment. We highlight the importance of genetic circuit design, reporter development, and chassis cell optimization to improve biosensors' performance. Bacterial arsenic resistances involving several processes, such as uptake, transformation, and methylation, engineered in customized bacteria have been summarized for arsenic bioaccumulation, detoxification, and biosorption. In this review, we present recent insights on the use of synthetic bacteria designed with ars operons for developing tailored bacteria for controlling arsenic pollution, offering a promising avenue for future research and application in environmental protection. [ABSTRACT FROM AUTHOR]

Arsenic contamination not only complicates mineral processing but also poses environmental and health risks. To address these challenges, this research investigates the feasibility of utilizing Hyperspectral imaging combined with machine learning techniques for the identification of arsenic-containing minerals in copper ore samples, with a focus on practical application in sorting and processing operations. Through experimentation with various copper sulfide ores, Neighborhood Component Analysis (NCA) was employed to select essential wavelength bands from Hyperspectral data, subsequently used as inputs for machine learning algorithms to identify arsenic concentrations. Results demonstrate that by selecting a subset of informative bands using NCA, accurate mineral identification can be achieved with a significantly reduced the size of dataset, enabling efficient processing and analysis. Comparison with other wavelength selection methods highlights the superiority of NCA in optimizing classification accuracy. Specifically, the identification accuracy showed 91.9% or more when utilizing 8 or more bands selected by NCA and was comparable to hyperspectral data analysis with 204 bands. The findings suggest potential for cost-effective implementation of multispectral cameras in mineral processing operations. Future research directions include refining machine learning algorithms, exploring broader applications across diverse ore types, and integrating hyperspectral imaging with emerging sensor technologies for enhanced mineral processing capabilities. [ABSTRACT FROM AUTHOR]

In this study, arsenic (As) speciation was investigated in the freshwater alga Chlamydomonas reinhardtii treated with 20 μg/L arsenate using fractionation as well as ICP-MS/ESI-MS analyses and was compared with the known As metabolite profile of wild-grown Saccharina latissima. While the total As accumulation in C. reinhardtii was about 85% lower than in S. latissima, the relative percentage of arsenolipids was significantly higher in C. reinhardtii (57.0% vs. 5.01%). As-containing hydrocarbons and phospholipids dominated the hydrophobic As profile in S. latissima, but no As-containing hydrocarbons were detectable in C. reinhardtii. Instead for the first time, an arsenoriboside-containing phytol (AsSugPhytol) was found to dominate the hydrophobic arsenicals of C. reinhardtii. Interestingly, this compound and its relatives had so far been only found in green marine microalgae, open sea plankton (mixed assemblage), and sediments but not in brown or red macroalgae. This compound family might therefore relate to differences in the arsenic metabolism between the algae phyla. [ABSTRACT FROM AUTHOR]

The use of probiotic lactobacilli has been proposed as a strategy to mitigate damage associated with exposure to toxic metals. Their protective effect against cationic metal ions, such as those of mercury or lead, is believed to stem from their chelating and accumulating potential. However, their retention of anionic toxic metalloids, such as inorganic arsenic, is generally low. Through the construction of mutants in phosphate transporter genes (pst) in Lactiplantibacillus plantarum and Lacticaseibacillus paracasei strains, coupled with arsenate [As(V)] uptake and toxicity assays, we determined that the incorporation of As(V), which structurally resembles phosphate, is likely facilitated by phosphate transporters. Surprisingly, inactivation in Lc. paracasei of PhoP, the transcriptional regulator of the two-component system PhoPR, a signal transducer involved in phosphate sensing, led to an increased resistance to arsenite [As(III)]. In comparison to the wild type, the phoP strain exhibited no differences in the ability to retain As(III), and there were no observed changes in the oxidation of As(III) to the less toxic As(V). These results reinforce the idea that specific transport, and not unspecific cell retention, plays a role in As(V) biosorption by lactobacilli, while they reveal an unexpected phenotype for the lack of the pleiotropic regulator PhoP. [ABSTRACT FROM AUTHOR]

An analytical method for determination of inorganic arsenic species in retorted oil shale slurry by atomic absorption spectrometry coupled to hydride technique with ultrasound assisted acidic extraction is reported. Trivalent arsenic measurement employed sample stabilization with a pH 4.5 prior to reaction with the reducing agent and analysis. In contrast, total inorganic As depended upon the pre-reduction of As(V) to As(III) with KI and ascorbic acid in 6.0 M HCl and of As(V) was estimated by the difference of the total inorganic As and As(III) concentrations. The limit of quantification was 3.7 mg kg−1 for As(III) and 1.3 mg kg−1 for itAs. [ABSTRACT FROM AUTHOR]

In the face of flourishing industrialization and global trade, heavy metal and metalloid contamination of the environment is a growing concern throughout the world. The widespread presence of highly toxic compounds of arsenic, antimony, and cadmium in nature poses a particular threat to human health. Prolonged exposure to these toxins has been associated with severe human diseases, including cancer, diabetes, and neurodegenerative disorders. These toxins are known to induce analogous cellular stresses, such as DNA damage, disturbance of redox homeostasis, and proteotoxicity. To overcome these threats and improve or devise treatment methods, it is crucial to understand the mechanisms of cellular detoxification in metal and metalloid stress. Membrane proteins are key cellular components involved in the uptake, vacuolar/lysosomal sequestration, and efflux of these compounds; thus, deciphering the multilevel regulation of these proteins is of the utmost importance. In this review, we summarize data on the mechanisms of arsenic, antimony, and cadmium detoxification in the context of membrane proteome. We used yeast Saccharomyces cerevisiae as a eukaryotic model to elucidate the complex mechanisms of the production, regulation, and degradation of selected membrane transporters under metal(loid)-induced stress conditions. Additionally, we present data on orthologues membrane proteins involved in metal(loid)-associated diseases in humans. [ABSTRACT FROM AUTHOR]

Acute promyelocytic leukemia (APL), which was once considered one of the deadliest types of leukemia, has become a curable malignancy since the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) as clinical treatments. ATO, which has become the first-line therapeutic agent for APL, is derived from the natural mineral product arsenic, exemplifying an important role of natural products in the treatment of APL. Many other natural products, ranging from small-molecule compounds to herbal extracts, have also demonstrated great potential for the treatment and adjuvant therapy of APL. In this review, we summarize the natural products and representative components that have demonstrated biological activity for the treatment of APL. We also discuss future directions in better exploring their medicinal value, which may provide a reference for subsequent new drug development and combination therapy programs. [ABSTRACT FROM AUTHOR]

The treatment of laboratory waste containing arsenic compounds should be part of the chemical analysis protocol in educational and research institutions. An alternative procedure for the treatment of these residues is proposed for the development of a didactic analytical route in the detection of As3+, As5+, MMA (monomethylarsonic acid) and DMA (dimethylarsinic acid). The treatment is based on the coprecipitation of inorganic arsenic species with a quaternary ammonium salt (tetra-n-butylammonium perchlorate) in suspension. Detection occurred by controlling the hydride generation reactions and Atomic Absorption Spectrometry. The methylated species MMA and DMA remain in the supernatant and can be monitored by adjusting the pH, concentration of the borohydride reducer, and the use of auxiliary reducers (hydroxylamine hydrochloride and KI). Satisfactory selective detectability was obtained for each arsenic species present in the waste sample. This work contributes to the development of experiments to be implemented in Qualitative Analytical Chemistry and Instrumental Analysis classes. The results allow to approach the chemical vapor generation, which is generally not well explored in undergraduate classes. Discussion of this procedure is supported by a teaching proposal based on the theory of nascent hydrogen for inorganic arsenic species and the nucleophilic performance of the hydride ion for methylated species. This approach allows the student to contextualize important concepts such as Lewis structure, oxidation state and kinetics of arsenic hydride generation reactions. This interdisciplinary contextualization forms a common theoretical basis, preparing and enabling the student to research speciation analysis by hydride generation and to understand the most accepted theories. [ABSTRACT FROM AUTHOR]

Arsenic can accumulate in freshwater biota, sometimes reaching potentially harmful levels. However, the toxicity of arsenic strongly depends on which arsenic species are present. Although organic species are considered less harmful than inorganic ones, they have not been extensively studied in freshwater environments, and drivers of variation in arsenic speciation among sites and taxa remain unclear. We assessed concentrations of two organic arsenic species, arsenobetaine (AsB) and dimethylarsinic acid (DMA), in fish and invertebrates from three lakes near Sudbury, Ontario, Canada—a region with widespread mining impacts. Both AsB and DMA were detected in most samples (n = 212), varying across a wide range of concentrations (<0.001–30.144 and <0.006–5.262 mg/kg dry wt, respectively). The lake with the most severe mining impacts typically had the highest concentrations (designated by square brackets []) of AsB and DMA. In contrast, the percentage of total arsenic made up by AsB (%AsB) and DMA (%DMA) did not vary significantly between lakes. Arsenic speciation in fish muscle varied with fish size, selenium concentrations, and trophic elevation (inferred from nitrogen stable isotope ratios δ15N), but relationships with dietary carbon source (inferred from carbon stable isotope ratios δ13C) were more varied. Within all three lake food webs, [AsB] and [DMA] typically underwent biodilution, decreasing with trophic elevation (i.e., δ15N). Although the aforementioned factors explained some variation in arsenic speciation, there remains considerable unexplained variation. Further studies on arsenic speciation in freshwater biota should target a wider diversity of taxa to better understand drivers of variation in arsenic speciation. In addition, research emphasizing the percentage of inorganic arsenic and other organic arsenic species is needed to improve environmental and human health risk assessments. Environ Toxicol Chem 2024;43:833–846. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The total arsenic mass fraction as well as the arsenic speciation were studied in four different mushroom species with inductively coupled plasma mass spectrometry and high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry, respectively. Arsenic mass fractions detected in the mushrooms were covering a range from 0.3 to 22 mg As kg−1 dry mass. For the arsenic speciation, species like arsenobetaine, inorganic arsenic, or dimethylarsinic acid were found, which are commonly detected in mushrooms, but it was also proven that the recently discovered novel compound homoarsenocholine is present in Amanita muscaria and Ramaria sanguinea. Moreover, a previously unidentified arsenic species was isolated from Ramaria sanguinea and identified as trimethylarsonioacetamide, or in short: arsenobetaine amide. This new arsenical was synthesized and verified by spiking experiments to be present in all investigated mushroom samples. Arsenobetaine amide could be an important intermediate to further elucidate the biotransformation pathways of arsenic in the environment. [ABSTRACT FROM AUTHOR]

Simple Summary: This study explores the potential use of retinoic acid in treating a severe form of bladder cancer, known as basal muscle-invasive bladder cancer (MIBC), which is among the deadliest cancers in the United States of America. All-trans retinoic acid (tretinoin), commonly used in the differentiation therapy of blood cancer, is investigated in this study for its efficacy against MIBC. By treating bladder cancer cells with tretinoin, the study aimed to determine whether it could diminish the aggressive behavior of these cells. The findings show promising results, suggesting that tretinoin can indeed make the basal muscle cancer cells less aggressive by reducing cell proliferation and increasing differentiation markers. This research could lead to new treatment approaches that improve survival chances for patients with basal muscle-invasive bladder cancer. Bladder cancer (BC) is the eighth most common cause of cancer death in the United States of America. BC is classified into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Genetically, MIBCs are categorized into the more aggressive basal subtype or less aggressive luminal subtype. All-trans retinoic acid (tretinoin), the ligand for the RAR-RXR retinoic acid receptor, is clinically used as a differentiation therapy in hematological malignancies. This study aims to determine the effects of retinoic acid on arsenite-transformed malignant urothelial cells (UROtsa As), serving as a model for basal muscle-invasive bladder cancer. We treated three independent isolates of arsenite-transformed malignant human urothelial UROtsa cells (UROtsa As) with tretinoin for 48 h. Cell viability, proliferation, and apoptosis were analyzed using crystal violet staining and flow cytometry. mRNA and protein level analyses were performed using RT-qPCR and the Simple Western™ platform, respectively. Tretinoin was found to reduce cell proliferation and urosphere formation, as well as decrease the expression of basal markers (KRT1, KRT5, KRT6, EGFR) and increase the expression of luminal differentiation markers (GATA3, FOXA1). Mechanistically, the antiproliferative effect of tretinoin was attributed to the downregulation of c-myc. Our results suggest that targeting the retinoic acid pathway can diminish the aggressive behavior of basal muscle-invasive urothelial cancer and may enhance patient survival. [ABSTRACT FROM AUTHOR]

Simple Summary: Acute promyelocytic leukemia (APL) stands as a remarkable success in achieving high cure rates with chemotherapy-free treatment regimens. Despite these remarkable outcomes, hematologists managing patients with APL take into consideration the distinct side effects associated with the two dual differentiation agents, i.e., all-transretinoic acid (ATRA) and arsenic trioxide (ATO). The objective of this paper is to review relevant literature data and discuss the recommended management strategies of non-hematologic early and late complications that arosein patients diagnosed with APL who were treated with ATO and ATRA-based regimens. The hallmark of acute promyelocytic leukemia (APL) is the presence of the characteristic fusion transcript of the promyelocytic leukemia gene with the retinoic acid receptor α gene (PML::RARA). The PML::RARA fusion is a molecular target for all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Therapies based on ATRA plus ATO have excellent outcomes in terms of complete remission rates, overall survival, and achievement of deep and durable molecular responses with a very low incidence of relapse. However, although the combination of ATRA and ATO has lower hematologic toxicity than standard chemotherapy, its use is associated with a spectrum of distinctive toxicities, such as differentiation syndrome, liver toxicity, QT interval prolongation, and neurotoxicity. Rigorous monitoring of patients' clinical evolution is indispensable for identifying and addressing each complication. The objective is to maintain an equilibrium between treatment-induced adverse events and therapeutic efficacy. This paper focused on non-hematologic complications associated with the combination of ATRA and ATO. Additionally, we discuss late-onset complications of this therapy. In summary, the majority of treatment-related adverse events are manageable, self-limiting, and reversible. More so, there seems to be a lower incidence rate of secondary neoplasms compared to standard chemotherapy. However, further research is required to assess how the ATRA plus ATO regimen affects the emergence of additional comorbidities. [ABSTRACT FROM AUTHOR]

This article explores the synthesis and coordination behavior of 9,10-Diarsatriptycene, a unique molecule with potential applications in various fields. The authors focus on the synthesis of heavy pnictogen-containing DHT analogues using nonvolatile arsenic precursors, which eliminates the need for dangerous reagents. The structures of the synthesized compounds were analyzed, revealing the effects of the bridgehead element. The compounds were found to have different stability and coordination abilities, and one compound formed a supramolecular polymer structure. Further research is being conducted to explore the potential applications of these compounds. [Extracted from the article]

Arsenic is a common pollutant and impurity present in complex gold ores. In the pressure oxidation (POX) of refractory gold-bearing sulfides, a major environmental challenge is the treatment of the hazardous waste released from arsenic-bearing minerals during processing. While the bulk removal of arsenic from solution can occur during POX, the formation of stable arsenates relies on the operating conditions during POX and the subsequent curing stage. Herein, response surface methodology (RSM) and central composite design have been investigated as viable approaches for optimizing arsenic fixation during the curing of the POX product of arsenopyrite. Curing time (0–24 h) and temperature (60–120°C) were examined as the model variables for RSM optimization, and the performance was assessed via arsenic and iron precipitation, along with the change in free acid and sulfate concentrations. Experimental validation of the optimized model conditions demonstrated good agreement with the simulated outputs and provided a 10% increase in arsenic removal over the best model input. The formation of basic ferric arsenate sulfate and scorodite under these conditions was supported by RSM and confirmed via characterization. In the investigated system, the maximum arsenic removal occurs at a critical threshold temperature of 107°C, over which the scorodite formation decreases with temperature. Thermodynamic modeling revealed the preferable formation of soluble FeHAsO4+ complexes over scorodite above this threshold temperature, decreasing arsenic fixation at higher temperatures. [ABSTRACT FROM AUTHOR]

Soda smelting slag is generated during the processing of desulphurized paste from recycling of waste lead acid batteries and other lead containing secondary materials in tilting rotary furnaces, and it represents about 9.5 % of the mass of the charge entering the furnace. This type of slag is very reactive. It contains toxic substances (lead, arsenic and antimony) and because of the presence of alkaline compounds it is corrosive. In addition, it decomposes in contact with air, forming dust. Therefore, such hazardous product cannot be disposed without preliminary stabilization. The aim of the present work is to investigate the possibility for environmentally utilization of this slag. The conducted experiments have shown the possibility of extracting the sodium sulfate from the soda slag only by grinding in an aqueous medium with subsequent filtration. The resulting solution is subjected to sulfide purification from heavy non-ferrous metals and subsequent crystallization for obtaining a commercial product sodium sulfate. These processes could be easily implemented in companies that have applied Engitec’s technology for recycling spent lead-acid batteries and production of sodium sulfate from desulfurization of the lead paste. Implementation of these processes will eliminate the need for slag stabilization and prevent environmental problems. [ABSTRACT FROM AUTHOR]

• The speciation and distribution of arsenic in flue gas are summarized. • The application progress of adsorption method in gaseous arsenic removal is reviewed. • The mechanism of gaseous arsenic removal by adsorption is emphasized. Because of its high mobility and difficult capture, gaseous arsenic pollution control has become the focus of arsenic pollution control. It mainly exists in the form of highly toxic As 2 O 3 in the flue gas. Therefore, removing gaseous As 2 O 3 from flue gas is of great practical significance for arsenic pollution control. Stabilizing gaseous As 2 O 3 on the surface of adsorbents by physical or chemical adsorption is an effective way to reduce the content of arsenic in the flue gas and alleviate arsenic pollution. Over the past few decades, various adsorbents have been developed to capture gaseous As 2 O 3 in the flue gas, and their adsorption mechanisms have been studied in detail. Thus, it is necessary to review the strategies of arsenic removal from flue gas by adsorption, which can inspire further research. Based on summarizing the morphological distribution of gaseous As 2 O 3 in the flue gas, this review further summarizes the removal of gaseous As 2 O 3 by several adsorbents and the effect of temperature and the main components of the flue gas on arsenic adsorption. In addition, the mechanism of arsenic removal based on adsorption in the flue gas is discussed in depth through theoretical calculations, which is the particular focus of this review. Finally, prospects based on the present research state of arsenic removal by adsorption are proposed to provide ideas for developing effective and stable adsorbents for arsenic removal from flue gas. [Display omitted] [ABSTRACT FROM AUTHOR]

Groundwater in many places on Earth contains arsenic compounds. Arsenic (III) compounds must be oxidised to purify water containing arsenic effectively. The subject of this study is oxidation of arsenic (III) compounds in an aqueous solution. Today’s most common industrial arsenic oxidation method using aggressive oxidising agents such as chlorine or ozone has a number of serious disadvantages. The most problematic of these include extremely high risks to human health and the environment, the cost and overall complexity of the process. Catalytic oxidation of arsenic (III) compounds using atmospheric oxygen is an alternative free from the above disadvantages, yet, to date, no information about effective catalysts for this process has been presented in the literature. The arsenic (III) catalytic oxidation process is studied in an aqueous solution on a new active manganese dioxide (NAMD) synthesised by the author. A comparative experimental analysis is performed with other known modifications of manganese dioxide. It is shown that the new active manganese dioxide (NAMD) has high catalytic activity towards arsenic (III), this being confirmed experimentally in both a limited volume and a flow column mode. Some theoretical aspects of the mechanism for catalytic oxidation of arsenic (III) with oxygen on active manganese dioxide in an aqueous solution are also discussed on the basis of the research results. Experimental work is required at pilot plants in the field for successful industrial implementation of the technology for catalytic oxidation of arsenic (III) compounds on NAMD. Further laboratory research is necessary for developing a detailed theoretical basis for catalytic oxidation of arsenic in aqueous solutions. The results of this research are of interest to industrial companies specialising in removing arsenic compounds from water, to scientists and researchers studying catalytic oxidation of arsenic (III), as well as heterogeneous catalytic oxidation with oxygen in general. [ABSTRACT FROM AUTHOR]

Arsenic is an immunotoxic element that can be found in living organisms, being a part of many important biochemical processes. It interacts with different groups of proteins, lipids and, in increased quantities, affects oxidative processes. As a toxic element, arsenic concentrations are limited in drinking water and food products by Community Directives and national regulations. From 2020 to 2023, we investigated the dynamics of this element in the water and suspended matter from the Prut River ecosystems within the Republic of Moldova. The sources of pollution with arsenic compounds are various pesticides, herbicides, metallurgical enterprises and power plants that use fossil coal and fuel oil. The pollution with pharmaceutical preparations that contain arsenic compounds should also be mentioned. Arsenic compounds enter the body of animals and humans in increased quantities primarily through polluted air, especially in industrial areas near thermal power plants and facilities such as metallurgical, military, chemical and pharmaceutical plants, as well as through drinking and mineral water, grapes, fruits, seafood (fish, snails, algae), medicines, pesticides and herbicides. The risk of arsenic accumulation is also increased in tobacco smokers. [ABSTRACT FROM AUTHOR]

BACKGROUND: Xenobiotic metabolites are widely present in human urine and can indicate recent exposure to environmental chemicals. Proper inference of which chemicals contribute to these metabolites can inform human exposure and risk. Furthermore, longitudinal biomonitoring studies provide insight into how chemical exposures change over time. OBJECTIVES: We constructed an exposure landscape for as many human-exposure relevant chemicals over as large a time span as possible to characterize exposure trends across demographic groups and chemical types. METHODS: We analyzed urine data of nine 2-y cohorts (1999–2016) from the National Health and Nutrition Examination Survey (NHANES). Chemical daily intake rates (in milligrams per kilogram bodyweight per day) were inferred, using the R package bayesmarker, from metabolite concentrations in each cohort individually to identify exposure trends. Trends for metabolites and parents were clustered to find chemicals with similar exposure patterns. Exposure variation by age, gender, and body mass index were also assessed. RESULTS: Intake rates for 179 parent chemicals were inferred from 151 metabolites (96 measured in five or more cohorts). Seventeen metabolites and 44 parent chemicals exhibited fold-changes ≥10 between any two cohorts (deltamethrin, di-n-octyl phthalate, and di-isononyl phthalate had the greatest exposure increases). Di-2-ethylhexyl phthalate intake began decreasing in 2007, whereas both di-isobutyl and di-isononyl phthalate began increasing shortly before. Intake for four parabens was markedly higher in females, especially reproductive-age females, compared with males and children. Cadmium and arsenobetaine exhibited higher exposure for individuals >65 years of age and lower for individuals <20 years of age. DISCUSSION: With appropriate analysis, NHANES indicates trends in chemical exposures over the past two decades. Decreases in exposure are observable as the result of regulatory action, with some being accompanied by increases in replacement chemicals. Age- and gender-specific variations in exposure were observed for multiple chemicals. Continued estimation of demographic-specific exposures is needed to both monitor and identify potential vulnerable populations. [ABSTRACT FROM AUTHOR]

Waste solutions from the electrolytic production of copper contain significant amounts of copper and nickel sulfates, sulfuric acid, arsenic and other components of the copper electrolyte. The processing of such solutions is considered in this work not only from the point of view of environmental protection, but also in terms of extracting various valuable components from the electrolyte into commercial products. A thermodynamic analysis of the interactions between barium and arsenic, as well as their compounds in the Ba(AsO2)2-Ba3(AsO4)2-H2O system was carried out based on the E-pH diagram. The possibility of using barium compounds as a precipitant for arsenic from copper electrorefining solutions has been demonstrated. The efficiency of removing arsenic (more than 84%) from the electrolyte using barium oxide in the form of sparingly soluble barium arsenate has been established. By adding calculated amounts of zinc oxide into the working solution, it is possible to form solutions containing certain concentrations of Cu, Ni, and Zn. By further adding zinc oxide into the solution, its deep dehydration was achieved. The resulting copper-nickel-zinc and nickel-zinc solutions are the raw material for producing non-ferrous metal alloys using the electromembrane method. [ABSTRACT FROM AUTHOR]

Practically and theoretically important are studies aimed at creating new methods for purifying copper electrolyte with the removal of such a dangerous impurity as arsenic in a form suitable for the intended use. Using probabilistic deterministic planning of the experiment, the course of chemical reactions in manganese- and arsenic-containing systems, the directions of reactions and the stability of their constituent phases were studied. Based on experimental data and thermodynamic analysis, the probable behavior of chemical elements and their compounds, the limits of potential and pH, within which a given compound of an element must be stable, are determined. X-ray diffraction identified the formation of manganese arsenate (Mn3(AsO4)2·4H2O) in deposits formed during the extraction of arsenic from a copper electrolyte with manganese (IV) oxide. [ABSTRACT FROM AUTHOR]

As a kind of emerging contaminant, organoarsenic compounds have drawn wide concern because of their considerable solubilities in water, and the highly toxic inorganic arsenic species formed during their biotic and abiotic degradation in the natural environment. Thus, the effective removal and studying of the adsorption mechanism of organoarsenic compounds are of significant urgency. In this work, MnFe2O4 and MnFe2O4/graphene were prepared through a facile solvothermal method. From the results of the Transmission Electron Microscope (TEM) characterization, it can be found that MnFe2O4 nanoparticles were uniformly distributed on the surface of the graphene. And the specific surface area of the MnFe2O4/graphene was about 146.39 m2 g−1, much higher than that of the MnFe2O4 (86.15 m2 g−1). The interactions between organoarsenic compounds and adsorbents were conducted to study their adsorption behavior and mechanism. The maximum adsorption capacities of MnFe2O4/graphene towards p-arsanilic acid (p-ASA) and roxarsone (ROX) were calculated to be 22.75 and 30.59 mg g−1. Additionally, the ionic strength, negative ions, and humus were introduced to investigate the adsorption performance of organoarsenic compounds. Electrostatic adsorption and surface complexation are the primary adsorption mechanisms on account of X-ray photoelectron spectroscopy (XPS) and the Fourier-transform infrared spectroscopy (FT-IR) analysis. This research extends the knowledge into studying the interaction between organoarsenic species and hybrid nanomaterials in the natural environment. [ABSTRACT FROM AUTHOR]

Arsenite (As(III)) is the most toxic form of arsenic that is a serious concern for water contamination worldwide. Herein a ZnO/Halloysite (Hal) nanocomposite was prepared by the chemical bath deposition method (CBD) through seed-mediated ZnO growth on the halloysite for eliminating As(III) from the aqueous solution. The growth of ZnO on seeded halloysite was investigated based on the HMTA: Zn2+ molar ratio in the solution. An optimum molar ratio of HMTA:Zn for nucleation and growth of ZnO upon halloysite was obtained 1:2 based on morphological analysis. The TGA results confirmed that thermal stability of HNT was enhanced by ZnO decoration. The prepared ZnO/Hal nanocomposite at optimal conditions was employed for arsenite (As(III)) removal from aqueous solutions. Experimental data were evaluated with different isothermal, thermodynamic, and kinetic models. Based on the zeta potential results, Hal nanocomposites had a greater negative value than pure Hal. Therefore, the ZnO/Hal nanocomposite exhibited efficient As(III) adsorption with a removal efficiency of 76% compared to pure Hal with a removal efficiency of 5%. Adsorption isotherm was well correlated by both non-linear Langmuir and Sips models, exhibiting maximum adsorption capacity of As(III) at 42.07 mg/g, and 42.5 mg/g, respectively. As a result of the study, it was found that the fabricated Hal nanocomposite with low toxicity can be used effectively in water treatment. [ABSTRACT FROM AUTHOR]

Zintl phase thermoelectric materials have generated tremendous interest due to possessing structural features conducive to high thermoelectric performances. On the other hand, both arsenic and arsenic‐based compounds have become attractive in electronics due to having interesting properties like narrow bandgap, tunable carrier concentration, and non‐centrosymmetric structures. The structure of arsenic compounds plays a telling role in determining their efficiency as thermoelectric materials. They also show the scope to be doped as both p‐ and n‐type conduction providing exciting new materials with applications as a full module. These attributes make them appealing as thermoelectric materials for further research. This short review is an overview of the different structures of arsenic‐based Zintl ternary materials that have potential to be excellent thermoelectric materials. [ABSTRACT FROM AUTHOR]

Arsenic is a hazardous heavy metalloid that imposes threats to human health globally. It is widely spread throughout the environment in various forms. Arsenic-based compounds are either inorganic compounds (iAs) or organoarsenicals (oAs), where the latter are biotically generated from the former. Exposure to arsenic-based compounds results in varying biochemical derangements in living systems, leading eventually to toxic consequences. One important target for arsenic in biosystems is the network of metabolic enzymes, especially the superfamily of cytochrome P450 enzymes (CYPs) because of their prominent role in both endobiotic and xenobiotic metabolism. Therefore, the alteration of the CYPs by different arsenicals has been actively studied in the last few decades. We have previously summarized the findings of former studies investigating arsenic associated modulation of different CYPs in human experimental models. In this review, we focus on non-human models to get a complete picture about possible CYPs alterations in response to arsenic exposure. [ABSTRACT FROM AUTHOR]

Simple Summary: Arsenic is a known carcinogen for the human urinary bladder. The present study explored aberrant DNA methylation in rat bladder carcinogenesis induced by dimethylarsinic acid (DMAV), a primary arsenic metabolite. Genome-wide DNA methylation and microarray gene expression analyses of DMAV-induced rat urothelial carcinoma (UC) and the urothelium of rats treated with DMAV for 4 weeks identified 40 genes that were both hypermethylated and downregulated in DMAV-induced rat urothelial carcinoma. Notably, four of these genes (CPXM1, OPCML, TBX20, and KCND3) also showed reduced expression in the bladder urothelium after 4 weeks of exposure to DMAV. Furthermore, CPXM1 is aberrantly methylated and downregulated in human bladder cancers and human bladder cancer cells. Our findings highlight the significance of aberrant DNA methylation in DMAV-induced bladder carcinogenesis, implying early-stage arsenic-induced methylation changes. Arsenic is a known human urinary bladder carcinogen. While arsenic is known to cause aberrant DNA methylation, the mechanism of arsenic-triggered bladder carcinogenesis is not fully understood. The goal of this study was to identify aberrant DNA methylation in rat bladder urothelial carcinoma (UC) induced by dimethylarsinic acid (DMAV), a major organic metabolite of arsenic. We performed genome-wide DNA methylation and microarray gene expression analyses of DMAV-induced rat UCs and the urothelium of rats treated for 4 weeks with DMAV. We identified 40 genes that were both hypermethylated and downregulated in DMAV-induced rat UCs. Notably, four genes (CPXM1, OPCML, TBX20, and KCND3) also showed reduced expression in the bladder urothelium after 4 weeks of exposure to DMAV. We also found that CPXM1 is aberrantly methylated and downregulated in human bladder cancers and human bladder cancer cells. Genes with aberrant DNA methylation and downregulated expression in DMAV-exposed bladder urothelium and in DMAV-induced UCs in rats, suggest that these alterations occurred in the early stages of arsenic-induced bladder carcinogenesis. Further study to evaluate the functions of these genes will advance our understanding of the role of aberrant DNA methylation in arsenic bladder carcinogenesis, and will also facilitate the identification of new therapeutic targets for arsenic-related bladder cancers. [ABSTRACT FROM AUTHOR]

The article describes the synthesis and characterization of ternary oxoarsenates(III) of trivalent lanthanides. Compounds of lanthanides and arsenic(III) oxide were prepared and analyzed. The crystal structures of the compounds were investigated and described. The results bridge the structural gap between cerium and neodymium and expand the spectrum of ternary oxoarsenates(III) of lanthanides up to gadolinium. The compounds consist of lanthanide cations coordinated by oxygen atoms and arsenate anions filling the gaps between the cations. The crystal structure forms a network of interconnected layers. [Extracted from the article]

Lake sediments store metal contaminants from historic pesticide and herbicide use and mining operations. Historical regional smelter operations in the Puget Sound lowlands have resulted in arsenic concentrations exceeding 200 μg As g-1 in urban lake sediments. Prior research has elucidated how sediment oxygen demand, warmer sediment temperatures, and alternating stratification and convective mixing in shallow lakes results in higher concentrations of arsenic in aquatic organisms when compared to deeper, seasonally stratified lakes with similar levels of arsenic pollution in profundal sediments. In this study we examine the trophic pathways for arsenic transfer through the aquatic food web of urban lakes in the Puget Sound lowlands, measuring C and N isotopes–to determine resource usage and trophic level–and total and inorganic arsenic in primary producers and primary and secondary consumers. Our results show higher levels of arsenic in periphyton than in other primary producers, and higher concentrations in snails than zooplankton or insect macroinvertebrates. In shallow lakes arsenic concentrations in littoral sediment are similar to deep profundal sediments due to arsenic remobilization, mixing, and redeposition, resulting in direct arsenic exposure to littoral benthic organisms such as periphyton and snails. The influence of littoral sediment on determining arsenic trophic transfer is evidenced by our results which show significant correlations between total arsenic in littoral sediment and total arsenic in periphyton, phytoplankton, zooplankton, snails, and fish across multiple lakes. We also found a consistent relationship between percent inorganic arsenic and trophic level (determined by δ15N) in lakes with different depths and mixing regimes. Cumulatively, these results combine to provide a strong empirical relationship between littoral sediment arsenic levels and inorganic arsenic in edible species that can be used to screen lakes for potential human health risk using an easy, inexpensive sampling and analysis method. [ABSTRACT FROM AUTHOR]

Arsenic pollution in water sources has been a recurring issue for the nations where groundwater is the sole source of survival. While conventional pressure-driven membrane is the epitome of a water treatment solution, it is not without limitations for arsenic removal. Thus, adsorptive membranes are studied since they combine positive features of adsorption and ultrafiltration technology that makes them able to remove arsenic effectively while offering promising flux. While there are studies reporting on the roles of adsorptive membranes for arsenic removal, there is much to discover on the performance of different adsorptive membranes in terms of adsorption capacity, regeneration potential, and stability. In this review, we survey the characteristics of a wide range of nanoadsorbents focussing on the membrane properties for arsenic removal as well as regeneration process of adsorptive membrane using different solutions. The key challenges faced during membrane fabrication and operation are also highlighted providing a better insight toward development of more robust adsorptive membranes. It is hoped that through this review, researchers will be inspired to develop more functional adsorptive membranes with not only outstanding performance but also stable performance for arsenic removal. [ABSTRACT FROM AUTHOR]

The current recycling water supply of metallurgical enterprises does not completely eliminate the discharge of wastewater into environmental water bodies, where the maximum permissible concentration (MPC) of arsenic is 0.05 mg/dm³. Arsenic accumulates in large quantities in washing solutions for cleaning exhaust gases sent to produce sulfuric acid. In this case, a closed gas washing system is used, aimed at concentrating the washing water with arsenic to 10 g/dm³ and sulfuric acid to 40 g/dm³ in order to reduce the volume of wastewater discharge. Another source of arsenic contamination of the hydrosphere is the waters of tailings from enrichment plants, due to the possible oxidation of arsenopyrite and the formation of a soluble form of arsenic compounds. A number of methods for arsenic precipitation have been developed: pyrolusite, lime in the form of calcium arsenate; ions of ferric iron and other metals; adsorption by iron (III) hydroxide, aluminum hydroxide, carbon, etc.; sludge flotation; metal sulfides, sorption and extraction. The main criterion for the operation of purifying a solution from arsenic is the possibility of recycling the resulting sediment or the formation of its compounds with minimal solubility in aqueous solutions, allowing its burial in burial grounds. [ABSTRACT FROM AUTHOR]

The removal of arsenic from the technological circulation of metallurgical enterprises is a technologically necessary process, leading from year to year to the formation of new volumes of arsenic-containing objects. One of the forms of extracting arsenic from the production stage is arsenates of various metals, which are difficult and poorly soluble compounds. This approach also does not solve environmental issues in general. Thus, titanium arsenates under storage and burial conditions are subject to hydrolysis, which leads to gradual pollution and poisoning of the environment with arsenic-containing compounds. The practical value of titanium and its compounds in economic activities forces us to look for ways to rationally use arsenic-containing titanium compounds. The article is the first to carry out a thermodynamic analysis of the behavior of arsenic and titanium based on potential-pH diagrams and partial pressures. The course and directions of chemical reactions in titaniumand arsenic-containing systems, the conditions for the stability of their constituent phases, the thermodynamic parameters of the behavior of the participating components, their compounds, the range of their stability, and the redox processes of the formation of chemical products have been studied. The regions of existence of titanium arsenate are determined, and chemical and electrode reactions for the production of titanium arsenate from titanium and arsenic compounds are considered. The results of the work confirm both the effectiveness of using titanium compounds to remove arsenic from solutions in the form of poorly soluble manganese arsenate, and the possibility of regenerating titanium in the form of oxides and bases. [ABSTRACT FROM AUTHOR]

• nZVI/biochar (ISBC) could efficiently degrade p-arsanilic acid (AA). • As(III) on AA was almost completely oxidized to As(V) and finally removed by ISBC. • Concentrations of inorganic arsenic after treatment reached drinking water standards. • Microplastics had little effect on AA degradation in the ISBC/PDS system. • Microplastics affect the migration of by-products (inorganic arsenic). P-arsanilic acid (AA) has received widespread attention because of its conversion to more toxic inorganic arsenic compounds (arsenate and arsenite) in the natural ecosystems. Its removal process and mechanisms with co-existence of microplastics remain unkown. In this study, biochar loaded with nano zero-valent iron (nZVI) particles (ISBC) was prepared by using iron scrap obtained from a steel works and wood chips collected from a wood processing plant. The advanced oxidation system of sodium persulfate (PDS) activated by ISBC was applied for AA degradation and inorganic arsenic control in aqueous media. More than 99% of the AA was completely degraded by the ISBC/PDS system, and the As(III) on AA was almost completely oxidized to As(V) and finally removed by ISBC. HCO 3 − inhibited the removal of AA by the ISBC/PDS system, while Cl− had a dual effect that showing inhibition at low concentrations yet promotion at high concentrations. The effect of microplastics on the degradation of AA by the ISBC/PDS system was further investigated due to the potential for combined microplastic and organic arsenic contamination in rural/remote areas. Microplastics were found to have little effect on AA degradation in the ISBC/PDS system, while affect the transport of inorganic arsenic generated from AA degradation. Overall, this study provides new insights and methods for efficient removal of p-arsanilic acid from water with coexisting microplastics. [Display omitted] [ABSTRACT FROM AUTHOR]

The article focuses on differentiation syndrome in acute promyelocytic leukemia (APL) and the role of Auer rods in identifying maturing promyelocytes during treatment. Topics include the unique persistence of Auer rods during differentiation, the significance of ATRA-ATO therapy in inducing promyelocyte maturation, and the importance of distinguishing differentiation-related changes from poor treatment response.