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Microbially-mediated arsenic biotransformation plays a pivotal role in the biogeochemical cycling of arsenic; however, the presence of arsenic biotransformation genes (ABGs) in urban dust remains unclear. To investigate the occurrence and spatiotemporal distributions of ABGs, a total of one hundred and eighteen urban dust samples were collected from different districts of Xiamen city, China in summer and winter. Although inorganic arsenic species, including arsenate [As(V)] and arsenite [As(III)], were found to be predominant, the methylated arsenicals, particularly trimethylarsine oxide [TMAs(V)O] and dimethylarsenate [DMAs(V)], were detected in urban dust. Abundant ABGs were identified in urban dust via AsChip analysis (a high-throughput qPCR chip for ABGs), of which As(III) S-adenosylmethionine methyltransferase genes (arsM), As(V) reductase genes (arsC), As(III) oxidase genes (aioA), As(III) transporter genes (arsB), and arsenic-sensing regulator genes (arsR) were the most prevalent, collectively constituting more than 90 % of ABGs in urban dust. Microbes involved in arsenic methylation were assigned to bacteria (e.g., Actinomycetes and Alphaproteobacteria), archaea (e.g., Halobacteria), and eukaryotes (e.g., Chlamydomonadaceae) in urban dust via the arsM amplicon sequencing. Temperature, a season-dependent environmental factor, profoundly affected the abundance of ABGs and the composition of microbes involved in arsenic methylation. This study provides new insights into the presence of ARGs within the urban dust., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Arsenic (As) speciation analysis is scientifically relevant due to the pivotal role the As chemical form plays in toxicity, which, in turn, directly influences the effect it has on the environment. The objective of this study was to develop and optimize a method tailored for studying As compounds in plant samples. Different extraction procedures and HPLC methods were explored to assess their efficiency, determine mass balance, and improve the resolution of compounds in the chromatograms. Conventionally applied anion-exchange chromatography facilitated the separation of well-documented As compounds in the extracts corresponding to 19 to 82% of As present in extracts. To gain insight into compounds which remain undetectable by anion chromatography (18 to 81% of As in the extracts), but still possibly metabolically relevant, we explored an alternative chromatographic approach. The procedure of sample purification and preconcentration through solid-phase extraction, facilitating the detection of those minor As compounds, was developed. The system was further refined to achieve an online 2D-RP-HPLC system, which was employed to analyze the extracts more comprehensively with ICP and ESI MS. Using this newly developed method, As(III)-phytochelatins, along with other arseno-thio-compounds, were detected and identified in extracts derived from the tree roots of seedlings grown in the presence of As(III) and As(V), and a group of arseno lipids was detected in the roots of plants exposed to As(V).

Rice is a staple food and known to accumulate inorganic arsenic (iAs), which is a class 1 carcinogen to humans. Arsenic field-deployable method kits, designed for water testing, are able to screen iAs in rice, to assure food safety and quick decision-making without the need for laboratory analysis. For the arsenic extraction within the field method, nitric acid is used. To make the field method on-site safer, cost-effective and easier to handle, the method was adapted using a Cola in the extraction process. The adapted field-deployable method was tested by screening a total of 30 rice and rice products from the Austrian market. To verify the results obtained by the Cola extraction field-deployable method, the obtained iAs concentration was compared to HPLC-ICP-MS results. The Cola extraction field method obtained an LOD of 39 µg iAs kg -1 rice, and with an average reproducibility of 14% RSD, the method was capable of recording no false-negative but 7% false-positive values at the 2023 updated European Commission (EC) limits for rice. All, but one, screened rice samples were within the EU limits for iAs in rice and rice products., (© 2023. The Author(s).)

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., (© 2024. The Author(s).)

The ability of an organism to biomethylate toxic inorganic arsenic (As) determines both, the amount of As available for uptake higher up the food chain and the toxicity of bioavailable As. An exposure study was conducted to determine ability of farmed crickets to metabolize dietary arsenate. Crickets were exposed to 1.3 ± 0.1, 5.1 ± 2.5 and 36.3 ± 5.6 mg kg -1 dietary arsenate and quantitation of total As showed retention of 0.416 ± 0.003, 1.3 ± 0.04 and 2.46 ± 0.09 mg kg -1 , respectively. Speciation analysis revealed that crickets have well developed ability to biomethylate dietary arsenate and the most abundant methylated As compound was DMA followed by MMA, TMAO and an unknown compound. Arsenobetaine, although present in all feed, control and As-rich, was measured only in the control crickets. To assess the bio-accessibility of the As species, crickets were subjected to simulated gastrointestinal digestion. The results showed that majority of As was extracted in saliva, followed by gastric and intestinal juice, which mass fraction was equal to residue. Over 78% of total As was shown to be bio-accessible with methylated species reaching 100% and iAs over 79% bio-accessibility. Additionally, arsenite and arsenate have shown different distributions between sequential leachate solutions. Bioaccumulation of As was observed in the studied crickets although it does not seem to occur to the same extent at higher exposure levels., Competing Interests: Declaration of competing interest There are not conflicts of interest to declare., (Copyright © 2023. Published by Elsevier Ltd.)

Arsenic occurs as a natural contaminant of drinking water supplies in arsenic endemic areas, posing a threat to public health. Our aim was to evaluate the relationship between urinary arsenic concentrations and spontaneous pregnancy loss in a population with low-moderate level drinking water arsenic exposure (mostly <10 μg/L). We enrolled 150 women with incident spontaneous pregnancy losses and 150 controls with ongoing pregnancies matched by gestational age. We measured arsenic species in urine using high performance liquid chromatography paired to inductively coupled plasma mass spectrometry. Urinary arsenic was not related to spontaneous pregnancy loss in conditional logistic regression models adjusted for confounding factors. However, a 10 μg/L increase in urinary arsenic (III + V) salt concentrations was associated with 8.00-fold (95% CI: 0.68, 3.35 × 10 5 ) greater odds of spontaneous loss among women using prenatal vitamins in an interaction model (P for interaction = 0.07), although the effect estimate was imprecise. In an additional interaction model, prenatal vitamin use was associated with lower odds of loss (OR = 0.30; 95% CI: 0.13, 0.66), although the association was diminished in the presence of a 10 μg/L increase in urinary inorganic arsenic (OR = 0.44; 95% CI: 0.70, 3.22). Total urinary arsenic was associated with 1.48-fold (95% CI: 0.20, 11.35) greater odds for loss among women with urinary cotinine >50 μg/L in another interaction model (P for interaction = 0.07). These results suggest a potential modest increase in the odds of pregnancy loss associated with increased total urinary arsenic among women smoking during pregnancy (urinary cotinine >50 μg/L). Prenatal vitamin use may act as a protective factor for arsenic exposure associated pregnancy loss, but appears to be less protective with increasing urinary inorganic arsenic concentrations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Accumulation of inorganic arsenic (iAs) and dimethylarsenate (DMA) in rice threatens human health and rice yield, respectively. We studied the yet unclear interactions of soil sulfate amendment and water management for decreasing As accumulation in rice grain in a pot experiment. We show that soil sulfate amendment (+200 mg S/kg soil) decreased grain iAs by 44% without clearly increasing grain DMA under intermittent flooding from booting stage to maturation. Under continuous flooding during this period, sulfate amendment decreased grain iAs only by 25% but increased grain DMA by 68%. The mechanisms of sulfate amendment effects on grain iAs were not explained by porewater composition or in-planta As sequestration but were allocated to the rhizosphere. Grain iAs closely correlated with As in the root iron-plaque (r = 0.92) which was effectively decreased by sulfate amendment and may have acted as an iAs source for rice uptake. Although both sulfate amendment and intermittent flooding substantially increased porewater DMA concentrations, it was the continuous flooding, irrespective of sulfate amendment, that resulted in rice straighthead disease with 47-55% less yield and 258-320% more DMA in grains than intermittent flooding. This study suggests that combining soil sulfate amendment and intermittent flooding can help to secure the quantity and quality of rice produced in As-affected areas. Our results also imply the key role of rhizosphere processes in controlling both iAs and DMA accumulation in rice which should be elucidated in the future., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Long term exposure to arsenic through consumption of contaminated groundwater has been a global issue since the last five decades; while from an alternate standpoint, arsenic compounds have emerged as unparallel chemotherapeutic drugs. This review highlights the contribution from arsenic speciation studies that have played a pivotal role in the progression of our understanding of the biological behaviour of arsenic in humans. We also discuss the limitations of the speciation studies and their association with the interpretation of arsenic metabolism. Chromatographic separation followed by spectroscopic detection as well as the utilization of biotinylated pull-down assays, protein microarray and radiolabelled arsenic have been instrumental in identifying hundreds of metabolic arsenic conjugates, while, computational modelling has predicted thousands of them. However, these species exhibit a variegated pattern, which supports more than one hypothesis for the metabolic pathway of arsenic. Thus, the arsenic species are yet to be integrated into a coherent mechanistic pathway depicting its chemicobiological fate. Novel biorelevant arsenic species have been identified due to significant evolution in experimental methodologies. However, these methods are specific for the identification of only a group of arsenicals sharing similar physiochemical properties; and may not be applicable to other constituents of the vast spectrum of arsenic species. Consequently, the identity of arsenic binding partners in vivo and the sequence of events in arsenic metabolism are still elusive. This resonates the need for additional focus on the extraction and characterization of both low and high molecular weight arsenicals in a combinative manner., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The emission and accumulation of toxic elements such as arsenic in various environmental compartments have become increasingly frequent primarily due to anthropogenic actions such as those observed in agricultural, industrial, and mining activities. An example of environmental arsenic contamination in Brazil exists in the city of Paracatu, MG, due to the operation of a gold mine. The aim of this work is to evaluate the routes and effects of arsenic contamination in environmental compartments (air, water, and soil) and environmental organisms (fish and vegetables) from mining regions as well as the trophic transfer of the element for a risk assessment of the population. In this study, high levels of arsenic were found in the waters of the Rico stream ranging from 4.05 µg/L during the summer season to 72.4 µg/L during the winter season. Moreover, the highest As concentration was 1.668 mg kg -1 in soil samples, which are influenced by seasonal variation and by proximity to the gold mine. Inorganic and organic arsenic species were found above the allowed limit in biological samples, indicating the transfer of arsenic found in the environment and demonstrating a great risk to the population exposed to this area. This study demonstrates the importance of environmental monitoring to diagnose contamination and encourage the search for new interventions and risk assessments for the population.

Millions of people are at risk of consuming arsenic (As) contaminated drinking water in Pakistan. The current study aimed to investigate urinary arsenic species [iAs III , iAs V , dimethylarsinic acid (DMA), methylarsonic acid (MMA)] and their potential toxicity biomarkers (based on urinary metabolome) in order to characterize the health effects in general adult male participants (n = 588) exposed to various levels of arsenic in different floodplain areas of Pakistan. The total urinary arsenic concentration (mean; 161 μg/L) of studied participants was lower and/or comparable than those values reported from other highly contaminated regions, but exceeded the Agency for Toxic Substances and Disease Registry (ATSDR) limits. For all the participants, the most excreted species was DMA accounting for 65% of the total arsenic, followed by MMA (20%) and iAs (16%). The percentage of MMA detected in this study was higher than those of previously reported data from other countries. These results suggested that studied population might have high risk of developing arsenic exposure related adverse health outcomes. Furthermore, random forest machine learning algorithm, partial correlation and binary logistic regression analysis were performed to screen the arsenic species-related urinary metabolites. A total of thirty-eight metabolites were extracted from 2776 metabolic features and identified as the potential arsenic toxicity biomarkers. The metabolites were mainly classified into xanthines, purines, and amino acids, which provided the clues linking the arsenic exposure with oxidative stress, one-carbon metabolism, purine metabolism, caffeine metabolism and hormone metabolism. These results would be helpful to develop early health warning system in context of arsenic exposure among the general populations of Pakistan., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Environmental inorganic arsenic (iAs) exposure is potentially related to abnormal blood pressure (BP) changes and abnormal platelet activation. However, limited epidemiological studies have explored the impacts of iAs exposure on platelet change mediated by BP, especially for pregnant women., Objectives: Our purpose was to investigate the associations of arsenic exposure with blood pressure and platelet indices among pregnant women., Methods: The present study population included 765 pregnant women drawn from a prospective birth cohort study in Wuhan, China, recruited between October 2013 and April 2016. Urine sampled in the second trimester were used to assess arsenic species concentrations. The relative distribution of urinary arsenic species was used to measure human methylation capacity. BP parameters and platelet indices originated from the medical record. We applied multivariable linear regression models to explore the cross-sectional relationships between urinary arsenic metabolites, BP parameters, and platelet indices. We utilized mediation analysis to investigate the impacts of arsenic exposure on platelet indices through BP as mediator variables., Results: We observed significant positive correlations between iAs and systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP). Pregnant women with higher methylation capacity to metabolize iAs characterized by higher secondary methylation index (SMI) and total methylation index (TMI) had a more significant reduction in SBP, DBP, and MAP. Pregnant women with higher DBP and MAP had higher platelet counts (PLC). A decreased PLC was found in subjects wither higher SMI. Additionally, SMI was negatively linked to PLC mediated through MAP., Conclusions: Obtained results suggested that higher methylation capacity to metabolize iAs might contribute to decreased PLC among pregnant women, and MAP might mediate the influence of SMI on PLC., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Inc.)

In certain populations, rice is the main source of exposure to inorganic arsenic (iAs), which is associated with cancer and non-cancer effects. Although rice is a staple food in Brazil, there have been few studies about the health risks for the Brazilian population. The objective of this study was to assess the risks of exposure to iAs from white rice and brown rice in Brazil, in terms of the carcinogenic and non-carcinogenic effects, and to propose measures to mitigate those risks. The incremental lifetime cancer risk (ILCR) and hazard quotient (HQ) were calculated in a probabilistic framework. The mean ILCR was 1.5 × 10 -4 for white rice and 6.0 × 10 -6 for brown rice. The HQ for white and brown rice was under 1. The ILCR for white and brown rice was high, even though the iAs concentration in rice is below the maximum contaminant level. The risk for brown rice consumption was lower, which was not expected. Various mitigation measures discussed in this report are estimated to reduce the risk from rice consumption by 5-67%. With the support of public policies, measures to reduce these risks for the Brazilian population would have a positive impact on public health.

Arsenic (As) compounds can be classified as organic or inorganic, with inorganic arsenic (iAs) having significantly higher toxicity than organic As. As may accumulate in food materials that have been exposed to As-contaminated environments. Thus, the "Sanitation Standard for Contaminants and Toxins in Foods" published by the Ministry of Health and Welfare set the standard limits for iAs content in rice, seaweed, seafood, and marine oils to safeguard public health. Therefore, a robust analytical method must be developed to selectively and quantitatively determine iAs content in rice, seaweed, seafood, and marine oils. Herein, we reported and verified the method of combined high-performance liquid chromatography/inductively coupled plasma-mass spectrometry (HPLC/ICP-MS) to determine iAs content in a wide variety of food. The fish oil samples were spiked with different concentrations of the As(III) standard solution, and their iAs analyzes were obtained via extraction procedures using the 1% (w/w) nitric acid (HNO 3 ) solution containing 0.2 M hydrogen peroxide (H 2 O 2 ) under sonication. The extracts were subsequently analyzed for their As(V) contents using HPLC/ICP-MS with aqueous ammonium carbonate as the mobile phase. The As(III) species had completely oxidized into the As(V) species, which prevented interferences between organic and iAs during chromatography. The method showed good extraction efficiencies (generally >90%) for the iAs samples, and their limits of quantification in fish oil were 0.02 mg/kg. The method was verified via the iAs speciation analytes of rice, seaweed, seafood, and marine oil matrices. The average recoveries for the fortified samples of each matrix ranged from 87.5 to 112.4%, with their coefficients of variation being less than 10%. Surveillance studies were conducted on the iAs contents of food samples purchased from local Taiwanese markets. The results showed that the only Hijiki (Sargassum fusiforme) higher than the maximum limit of the sanitation standard for iAs in seaweed, whereas the remaining samples met their corresponding requirements. This method is quick and straightforward, and it can be applied for the routine analysis of iAs content in a wide variety of food products to ensure public health safety.

Arsenic (As) exposure has been extensively studied by investigating As species (e.g., inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)) in urine, yet recent research suggests that blood could be a possible biomarker of As exposure. These investigations, however, were conducted on iAs-contaminated areas, and evidence on populations exposed to low levels of iAs is limited. This study aimed to describe the levels and distributions of As species in urine and blood, as well as to estimate methylation efficiency and related factors in the Korean population. Biological samples were obtained by the Korean Ministry of Food and Drug Safety. A total of 2025 urine samples and 598 blood samples were utilized in this study. Six As species were measured using ultra-high-performance liquid chromatography with inductively coupled plasma mass spectrometry (UPLC-ICP-MS): As(V), As(III), MMA, DMA, arsenobetaine (AsB), and arsenocholine (AsC). Multiple linear regression models were used to examine the relationship between As species (concentrations and proportions) and covariates. AsB was the most prevalent species in urine and blood. The relative composition of iAs, MMA, DMA, and AsC in urine and blood differed significantly. Consumption of blue-backed fish was linked to higher levels of AsB in urine and blood. Type of drinking water and multigrain rice consumption were associated with increased iAs concentration in urine. Except for iAs, every species had correlations in urine and blood in both univariate and multivariate analyses. Adolescents and smokers presented a lower methylation efficiency (higher %MMA and lower %DMA in urine) and females presented a higher methylation efficiency (lower %iAs, %MMA, and higher %DMA in urine). In conclusion, blood iAs concentration cannot represent urinary iAs; nonetheless, different compositions of urine and blood might reflect distinct information about iAs exposure. Further investigations on exposure factors and health are needed using low-exposure groups., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Gut bacteria are at the interface of environmental exposures and their impact on human systems, and may alter host absorption, metabolism, and excretion of toxic chemicals. We investigated whether arsenic-metabolizing bacterial gene pathways related to urinary arsenic concentrations. In the New Hampshire Birth Cohort Study, urine and stool samples were obtained at six weeks (n = 186) and one year (n = 190) of age. Inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AsB) were quantified in infant urine samples using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Total arsenic exposure (tAs) was summarized as Σ(iAs, MMA, DMA) and log 2 -transformed. Fecal microbial DNA underwent metagenomic sequencing and the relative abundance of bacterial gene pathways were grouped as KEGG Orthologies (KOs) using BioBakery algorithms. Arsenic metabolism KOs with >80% prevalence were log 2 -transformed and modeled continuously using linear regression, those with <10% were not evaluated and those with 10-80% prevalence were analyzed dichotomously (detect/non-detect) using logistic regression. In the first set of models, tAs was regressed against KO relative abundance or detection adjusting for age at sample collection and child's sex. Effect modification by delivery mode was assessed in stratified models. In the second set of models, the association between the relative abundance/detection of the KOs and arsenic speciation (%iAs, %MMA, %DMA) was quantified with linear regression. Urinary tAs was associated with the increased relative abundance/detection odds of several arsenic-related KOs, including K16509, an arsenate reductase transcriptional regulator, with stronger associations among six-week-olds than one-year-olds. K16509 was also associated with decreased %MMA and increased %DMA at six weeks and one year. Notably, many associations were stronger among operatively-delivered than vaginally-delivered infants. Our findings suggest associations between arsenic-metabolizing bacteria in the infant gut microbiome and urinary arsenic excretion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

A facile method to selectively determine trace As(V) species in the existence of As(III) one in water samples was developed, which was based on the batch adsorption process by using a miniaturized MIL-101(Fe) mixed-matrix membrane (MOF-MMM) followed by a direct determination through energy dispersive X-ray fluorescence (EDXRF) spectrometry. The quantitative adsorption of As(V) was achieved at pH (3-6) from 30 mL sample in 120 min of equilibrium time by employing the membrane with a monolayer adsorption capacity of Q o  = 1.953 mg g -1 . The direct determination of As(V) adsorbed on the membrane by EDXRF spectroscopy provided a method, not only easy-to-use and operable without elution stage, but also cost effective due to low gas consumption during the analysis. With a limit of detection of 0.094 μg L -1 , analytical performance of the method, which was evaluated on fortified real water samples with three levels of As(V) (5, 10 and 50 μg L -1 ), demonstrated good recoveries in the range of 98(±3)-105(±10)%. Furthermore, the speciation of As(III) and As(V) in the fortified real samples containing other ionic species was also successfully achieved by described approach with characteristics of simple, cheap, viable and reproducible., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Experimental studies have shown the diabetogenic potential of inorganic arsenic (iAs); however, the epidemiological evidence is still inconclusive. This could be explained by differences in exposure, metabolism efficiency, nutritional and genetic factors., Objective: To evaluate the association between type 2 diabetes mellitus (T2DM) prevalence with arsenic exposure and metabolism, considering one-carbon metabolism nutrient intake and arsenite methyltransferase (AS3MT) polymorphisms., Methods: From healthy controls of a case control study for female breast cancer in northern Mexico, 227 self-reported diabetic women were age-matched with 454 non-diabetics. Participants were interviewed about dietary, sociodemographic and clinical characteristics. Urinary iAs metabolites were determined by HPLC-ICP-MS, methylation efficiency parameters were calculated, and AS3MT c.860 T > C and c.529-56G > C genotypes were determined. Unconditional logistic regression models were used to evaluate associations., Results: Total arsenic in urine (TAs) ranged from 0.73 to 248.12 μg/L with a median of 10.48 μg/L. In unadjusted analysis, TAs (μg/g) was significantly higher in cases than controls, but not when expressed as TAs (μg/L). Cases had significantly lower urinary monomethylarsonic acid percentage (%MMA), first methylation ratio (FMR), creatinine, and choline and selenium intakes. In multi-adjusted models and in women without HTA history T2DM showed significant positive associations with %iAs and FMR, respectively, and a significant negative association with %DMA. In participants with HTA history there was a marginal positive association (p = 0.08) between T2DM and TAs concentrations (μg/g) without other significant associations., Conclusions: Our results support an association between T2DM prevalence and iAs metabolism but not with urinary arsenic levels. However, elucidation of the interplay among iAs metabolism, T2DM and HTA merit further studies., (Copyright © 2022 Elsevier Inc. All rights reserved.)

This paper presents a new method for the simultaneous speciation analysis of arsenic (As(III)-arsenite, As(V)-arsenate, DMA-dimethylarsinic acid, MMA-methylarsonic acid, and AsB-arsenobetaine) and selenium (Se(IV)-selenite, Se(VI)-selenate, Se-Methionine, and Se-Cystine), which was applied to a variety of seafood and onion samples. The determination of the forms of arsenic and selenium was undertaken using the High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS) analytical technique. The separation of both organic and inorganic forms of arsenic and selenium was performed using two analytical columns: an anion exchange column, Dionex IonPac AS22, containing an alkanol quaternary ammonium ion, and a double bed cation-anion exchange guard column, Dionex Ion Pac CG5A, containing, as a first layer, fully sulfonated latex for cation exchange and a fully aminated layer for anion exchange as the second layer. The ammonium nitrate, at pH = 9.0, was used as a mobile phase. The method presented here allowed us to separate the As and Se species within 10 min with a suitable resolution. The applicability was presented with different sample matrix types: seafood and onion.

Sea dumping of chemical warfare (CW) took place worldwide during the 20th century. Submerged CW included metal bombs and casings that have been exposed for 50-100 years of corrosion and are now known to be leaking. Therefore, the arsenic-based chemical warfare agents (CWAs), pose a potential threat to the marine ecosystems. The aim of this research was to support a need for real-data measurements for accurate risk assessments and categorization of threats originating from submerged CWAs. This has been achieved by providing a broad insight into arsenic-based CWAs acute toxicity in aquatic ecosystems. Standard tests were performed to provide a solid foundation for acute aquatic toxicity threshold estimations of CWA: Lewisite, Adamsite, Clark I, phenyldichloroarsine (PDCA), CWA-related compounds: TPA, arsenic trichloride and four arsenic-based CWA degradation products. Despite their low solubility, during the 48 h exposure, all CWA caused highly negative effects on Daphnia magna. PDCA was very toxic with 48 h D. magna LC50 at 0.36 μg × L -1 and Lewisite with EC50 at 3.2 μg × L -1 . Concentrations at which no immobilization effects were observed were slightly above the analytical Limits of Detection (LOD) and Quantification (LOQ). More water-soluble CWA degradation products showed no effects at concentrations up to 100 mg × L -1 ., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Since arsenic (As) exposure is largely due to geochemical contamination, this study focused on the remediated area of Santana do Morro, a district of Santa Bárbara, Minas Gerais, Brazil, which was previously contaminated with As due to gold mining. Total As concentrations in sediment, soil and plants were determined, next to As species, anionic arsenic compounds As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), in plants samples. Total As concentrations in soil and sediments were slightly elevated (16-18 µg g-1) and most of the plants contained low levels of As (< 1 µg g-1). The exception was a native plant Eleocharis geniculata (L.) which contained elevated levels of As (4 µg g-1). The exposure of this plant to As under controlled conditions (hydroponics) indicated its possible tolerance to elevated As levels and suggesting its potential use in phytomonitoring of As-contaminated sites. This plant is able to metabolize arsenate to arsenite and contained MMA and DMA, both in its natural habitat and under controlled conditions.

With recently legislated maximum levels of inorganic arsenic (iAs) in white and brown rice in Canada, the regulatory bodies are evaluating the need for regulation of As levels in infant food products. Rice is a major part of infants' diet, and therefore, the presence of As in this staple food causes concerns. So far, the scientific community was lacking suitable certified reference material (CRM) which could be used to assess the accuracy of developed analytical methods for As speciation in infants' food products. As a result, we have developed BARI-1, a baby cereal coarse rice flour reference material which was certified for total arsenic (0.248 ± 0.018 mg kg -1 ), cadmium (0.0134 ± 0.0014 mg kg -1 ), mercury (0.0026 ± 0.0003 mg kg -1 ), lead (0.0064 ± 0.0016 mg kg -1 ), inorganic As (0.113 ± 0.016 mg kg -1 ) and dimethylarsinic acid (DMA) (0.115 ± 0.010 mg kg -1 ), and reference value for monomethylarsonic acid (MMA) (0.0045 ± 0.0008 mg kg -1 ) was reported. We also observed trace amounts of an unknown As compound, with chromatographic retention time close to DMA. Participating laboratories were allowed to use their in-house-validated extraction and/or digestion methods, and the detection of total metals was done by ICP-MS whereas HPLC-ICP-MS was used for As speciation. Despite the diversity in sample preparation and quantitation methods, reported values were in good agreement. For iAs measurement, the comparison between hydride generation ICP-MS and HPLC-ICP-MS found iAs overestimation with the former method, possibly due to interference from DMA. The certification was accomplished with a CRM rapid response approach in collaborative, focused effort completing the CRM development in few months instead of the typical multiyear project. This approach allowed to respond to measurement needs in a timely fashion. Graphical abstract.

Temperature, light intensity (LI), adsorbent source and concentrations are key external factors affecting algal metabolism and thus metal-accumulation mechanisms. In this study, the alga Sarcodia suiae was exposed individually to a range of temperature (15, 20, and 25 °C), and LI (30, 55, and 80 μmol photons m -2  s -1 ) at initial arsenate [As(V)] concentration ( i conc: 0, 62.5, 125, 250, and 500 μg L -1 ) conditions, to investigate the variations of total arsenic (TAs) and inorganic arsenic (iAs) accumulation mechanisms in the algal body. Temperature significantly affected TAs and arsenite [As(III)] production and maximum absorption were obtained at 15 °C, which was significantly stimulated by increasing i conc. However, the temperature did not affect As(V) production. LI had no significant effect on TAs or iAs production, although maximum absorption was estimated in 80 μmol photons m -2  s -1 . The iAs component of TAs was much greater in the temperature experiment particularly under 250-500 μg L -1 i conc than in the LI experiment, is witnessed. Overall, temperature and i conc strongly affected As accumulation. The predominant iAs produced was As(III), regardless of temperature or LI, suggesting that the alga favored As(III) biosorption. Also, visible effects on the morphology of this alga were adverse with increased concentration and environmental factors did affect the difference somewhat. Our results contribute to improving our understanding of the effects of the tested factors on As cycling, which is necessary for maximizing biosorption of algae if utilized for bioremediation studies as well as in the wastewater treatment implementation approach in the environment., Competing Interests: Declaration of competing interest We declare no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

It has recently been discovered that organic and inorganic arsenics could be detrimental to human health. Although organic arsenic is less toxic than inorganic arsenic, it could form inorganic arsenic through chemical and biological processes in environmental systems. In this regard, the availability of tools for detecting organic arsenic species would be beneficial. Because As-sensing biosensors employing arsenic responsive genetic systems are regulated by ArsR which detects arsenics, the target selectivity of biosensors could be obtained by modulating the selectivity of ArsR. In this study, we demonstrated a shift in the specificity of E. coli cell-based biosensors from the detection of inorganic arsenic to that of organic arsenic, specifically phenylarsine oxide (PAO), through the genetic engineering of ArsR. By modulating the number and location of cysteines forming coordinate covalent bonds with arsenic species, an E. coli cell-based biosensor that was specific to PAO was obtained. Despite its restriction to PAO at the moment, it offers invaluable evidence of the potential to generate new biosensors for sensing organic arsenic species through the genetic engineering of ArsR.

Objective: To describe interindividual metabolism variations and sociodemographic characteristics associated to urinary arsenic, and to estimate the arsenic contamination in water from urinary total arsenic (TAs)., Materials and Methods: Women (n=1 028) from northern Mexico were interviewed about their sociodemographic characteristics and their urinary concentrations of arsenic species were measured by liquid chromatography. Inorganic arsenic (iAs) in water was estimated from urinary TAs., Results: Women were 20-88 years old. TAs in urine ranged from p10=3.41 to p90=56.93 μg/L; 74% of women had levels >6.4 μg/L. iAs in water varied from p10=3.04 to p90=202.12 μg/L; 65% of women had concentrations >10 μg/L, and 41%, concentrations >25 μg/L. Large variations in iAs metabolism were observed. TAs was significantly negatively associated with age and schooling, and positively with the state of residence., Conclusions: Exposure to iAs is an environmental problem in Mexico. Individual variations in metabolism are a challenge to design prevention and control programs., Competing Interests: Declaration of conflict of interests. The authors declare that they have no conflict of interests.

Background : Arsenic is a toxic metalloid element widely distributed throughout the environment. Arsenic contaminated water has become an ongoing public health issue affecting hundred million people worldwide. The aim of this paper was to summarize the evidence in the association between arsenic metabolites and urinary tract cancer risk. Methods : A systematic review was conducted searching for observational studies that evaluated the association of arsenic metabolites and urinary tract cancer. Risk estimates from individual studies were pooled by using random effects models. Results : All the metabolites considered in this study resulted to be significantly associated to urothelial cancer, respectively: IA% 3.51 (1.21-5.82) ( p = 0.003), MMA with WMD = 2.77 (1.67-3.87) ( p < 0.001) and DMA with WMD = -4.56 (-7.91-1.22) ( p = 0.008). Conclusions : Arsenic metabolites are significantly associated to urothelial cancer. Future studies will help to verify the independent association(s) between arsenic metabolites and urothelial cancer.

The bioaccessibility of total arsenic (tAs) and arsenic species in Bellamya aeruginosa collected from Xiangjiang River was evaluated using an in vitro digestion model, to assess the potential health risks to local residents. The tAs concentrations in gastropod samples ranged from 1.98 to 6.33 mg kg -1 (mean 3.79 ± 1.60 mg kg -1 ). Five arsenic species including arsenite [As(III)], arsenate [As(V)], dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) were detected. Inorganic arsenic (iAs) concentrations, which were about a half of organic arsenic (oAs), were higher than the maximum permissible limit (≤0.50 mg kg -1 in aquatic products). Bioaccessible concentrations of tAs in digestive juices were found to be decreased in the order: intestinal phase > gastric phase > salivary phase. As(III) and AsC were the predominant species, but AsB was not detectable in all digestive juices. Bioaccessible iAs concentrations, which were close to the level of bioaccessible oAs, were not significantly different among three digestive juices, but also above 0.50 mg kg -1 . Accordingly, bioaccessibility of tAs was highest in intestinal phase (48%), then in gastric phase (40%), and lowest in salivary phase (33%). Bioaccessibility of As(III) was close to 100%, and bioaccessibility of iAs was much higher than that of oAs. The mean values of target hazard quotient (THQ) and bioaccessible THQ were 0.80 and 0.70, respectively. The probability of experiencing non-carcinogenic effects was reduced to 18% down from 22% as considering iAs bioaccessibility. The mean values of carcinogenic risk (CR) and bioaccessible CR were higher than the acceptable value (1 × 10 -4 ). Gastropod consumption from sampling sites may cause a potential carcinogenic risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

High contents of arsenic were detected in soils in Guandu plain, northwest Taiwan. To determine the sources and speciation of As in the soils, the depth profiles of soil properties, elemental composition and As speciation were investigated. The As concentrations in the soil profile ranged from 152 to 1222 mg kg -1 , with the highest concentration at the depth of 70-80 cm. The As distribution was found to be positively correlated to Fe, Pb, and Ba. The As(V)-adsorbed ferrihydrite and scorodite were the predominant phases in the top layers (<50 cm), while beudantite was the predominant phase below 50 cm along with As(III)- and As(V)-adsorbed ferrihydrite as the minor components. The results of sequential extraction showed that As-associated with noncrystalline and crystalline Fe/Al hydrous oxides and residual phases were predominant at the depths of 0-60, 60-100 and 100-140 cm, respectively, indicating an increasing As recalcitrance with soil depth. Based on the soil properties, and elemental and mineral compositions at different soil depths, the origin of beudantite in the soils was likely allogenic rather than authigenic or anthropogenic. The formation of scorodite in the surface soils was suggested to be transformed from beudantite. As-associated Fe hydrous oxides may be contributed by the progressive dissolution of beudantite and scorodite, and the continuous influxes of As and Fe. While Fe hydrous oxides were able to immobilize As during the dissolution of As-bearing minerals, the increase of As mobility in soils may imply an increase in the environmental risk of As over time., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Rice-based products are widely used to feed infants and young children. However, the association of rice-based products and high arsenic (As) concentrations have been investigated in a number of studies, but there is limited information from Australia. Therefore, the purpose of this study was to determine the As concentration and dietary exposure in infant rice milk, cereal, crackers and pasta as well as to investigate the relationship between As concentration and rice content, rice type and product origin. Total arsenic (tAs) concentrations were determined by nitric acid digestion and ICP-MS while inorganic arsenic (iAs) was determined by acid extraction, followed by ICP-MS with an interfaced hydride generation system. Nearly 75% of samples had inorganic As exceeding the EU maximum levels for infants and children (0.1 mg kg -1 ) and the mean iAs percentage of total reached as high as 84.8%. High tAs concentration was positively correlated with rice content and also related to brown (wholegrain). Estimates of dietary exposure showed that infants consuming large amounts of rice pasta or crackers will have an increased risk of health impact associated with excess intake of As through dietary exposure. Moreover, the current Australian guidelines for As in rice (1 mg kg -1 ) are above the WHO or EU guideline and therefore, will be less protective of high sensitivity consumers like infants and children.

An inter-laboratory study was carried out to characterize a candidate hijiki seaweed for its concentrations of total arsenic and water-soluble arsenic compounds, particularly arsenosugar compounds. The candidate material, a dried hijiki seaweed powder, was analyzed by individual techniques in two laboratories. The water-soluble arsenic compounds were separated by anion exchange, and reversed-phase columns, and As(V), DMA and four kinds of arsenosugars, namely glycerol (-OH), phosphate (-PO 4 ), sulfonate (-SO 3 ), and sulfate (-SO 4 ) types were detected by HPLC-ICP-MS. The methods applied were validated by analyzing a second sample, the NMIJ CRM 7405-a hijiki seaweed, which is certified for both total arsenic and As(V). Techniques for the inter-laboratory study, extraction efficiencies under different extraction conditions, some chromatographic techniques and sequential extraction were investigated. The results from the two laboratories for the candidate hijiki material showed good agreement within the measurement uncertainties for total and water-soluble arsenic compounds.

Chloride widely exists in the environment and will cause serious interference for arsenic speciation analysis. The determination of four arsenic species including arsenite (As(III)), arsenate (As(V)), monomethylarsenate (MMA), and dimethylarsonate (DMA) in samples containing high concentrations of Cl - was carried out in this work by coupling of liquid chromatography (LC) with hydride generation atomic fluorescence spectrometry (HG-AFS). The interference of Cl - was successfully eliminated by coupling two anion-exchange chromatographic columns in series and eluting with 35.0 mmol L -1 (NH 4 ) 2 HPO 4 (pH = 6.00). A novel pre-treatment system was subsequently developed to realize on-line column switch and pre-reduction of As(V). The analysis time was shortened by an isocratic elution but programmed flow rate method, and the sensitivity of As(V) was also enhanced by the introduction of pre-reduction using the developed system. The proposed method can resist at least 10 g L -1  Cl - without any pre-treatment operations. Since LC-HG-AFS is low-cost and can be afforded or self-assembled by most labs, the developed method can be adopted as a routine analysis method for arsenic species in chloride-bearing samples, such as urine and seawater. Graphical abstract.

The rice consumption behaviors of Thai citizens vary among regions. However, the influence of different consumption patterns on arsenic (As) exposure has never been reported. This study was conducted to investigate the effects of rice consumption behavior on As exposure levels. White rice (n = 96) and sticky rice (n = 63) samples were collected from local households in northern Thailand. The actual rice consumption behavior (type, frequency, and amount of rice consumed) was surveyed from the households where the rice samples were collected and used to calculate individual As exposures. The white rice (2.1%) and sticky rice (6.3%) samples contained inorganic As at higher concentrations than the Codex standard (0.2 mg kg -1 ). Approximately 58.3% of participants consumed white rice for breakfast and sticky rice for lunch and dinner, while 41.8% of participants consumed only white rice or sticky rice daily. Wide variations of As exposure (1 × 10 -4 to 2 × 10 -3 mg kg -1 day -1 ) were found. The average As exposure from only sticky rice consumption and combined rice consumption was 2 times higher than the As exposure from only white rice consumption. The rice ingestion rate was the most important factor affecting the level of As exposure resulting from the white rice-only and combined rice consumption patterns. For the combined rice consumption pattern, 45.7 to 93.5% of the total As exposure was from sticky rice consumption. Regarding individual characteristics, older and lower weight participants tended to consume lower amounts of rice. Thus, lower As exposure and fewer health impacts were found in those participants.

Background: Chronic exposure to inorganic arsenic (iAs) in the US occurs mainly through drinking water and diet. Although American Indian (AI) populations have elevated urinary arsenic concentrations compared to the general US population, dietary sources of arsenic exposure in AI populations are not well characterized., Methods: We evaluated food frequency questionnaires to determine the major dietary sources of urinary arsenic concentrations (measured as the sum of arsenite, arsenate, monomethylarsonate, and dimethylarsinate, ΣAs) for 1727 AI participants in the Strong Heart Family Study (SHFS). We compared geometric mean ratios (GMRs) of urinary ΣAs for an interquartile range (IQR) increase in reported food group consumption. Exploratory analyses were stratified by gender and study center., Results: In fully adjusted generalized estimating equation models, the percent increase (95% confidence interval) of urinary ΣAs per increase in reported food consumption corresponding to the IQR was 13% (5%, 21%) for organ meat, 8% (4%, 13%) for rice, 7% (2%, 13%) for processed meat, and 4% (1%, 7%) for non-alcoholic drinks. In analyses stratified by study center, the association with organ meat was only observed in North/South Dakota. Consumption of red meat [percent increase -7% (-11%, -3%)] and fries and chips [-6% (-10%, -2%)] was inversely associated with urinary ΣAs., Conclusions: Organ meat, processed meat, rice, and non-alcoholic drinks contribute to ΣAs exposure in the SHFS population. Organ meat is a unique source of ΣAs exposure for North and South Dakota participants and may reflect local food consumption. Further studies should comprehensively evaluate drinking water arsenic in SHFS communities and determine the relative contribution of diet and drinking water to total arsenic exposure., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Dietary arsenic (As) intake from food is of great concern, and developing a reliable model capable of predicting As concentrations in plant edible parts is desirable. In this study, pot experiments were performed with 16 Chinese upland soils spiked with arsenate [As(V)] to develop a predictive model for As concentrations in pepper fruits (Capsicum annum L.). Our results showed that after three months' aging, concentrations of bioavailable As (extracted by 0.05 M NH 4 H 2 PO 4 ) in various soils varied widely, depending on soil total As concentrations and soil properties such as soil pH and amorphous iron (Fe) contents. Furthermore, both the bioconcentration factor (BCF, denoted as the ratio of fruit As to soil As) and total As concentrations in pepper fruits were largely determined by concentrations of bioavailable As, which explained 27% and 69% variations in the BCF and fruit As concentrations, respectively. Apart from bioavailable As, soil pH and Fe contents were another two important factors influencing As accumulation in pepper fruits. Taking the three factors into account, concentrations of fruit As can be well predicted using a stepwise multiple linear regression (SMLR) analysis (R 2  = 0.80, RMSE = 0.17). Arsenic species in soils and edible parts were also analyzed. Although As(V) predominated in soils (>96%), As in pepper fruits presented as As(V) (46%) and arsenite [As(III)] (39%) with small amount of methylated As (<15%). Aggregated boosted tree (ABT) analysis revealed that inorganic As concentrations in pepper fruits were determined by concentrations of bioavailable As, phosphorus (P) and Fe in soils. In contrast to inorganic As, methylated As concentrations were not correlated with those factors in soils. Taken together, this study established an empirical model for predicting As concentrations in pepper fruits. The predictive model can be used for establishing the As threshold in fruit vegetable farming soils., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Arsenic contamination in marine environments is a serious issue because some arsenicals are very toxic, increasing the health risks associated with the consumption of marine products. This study describes the development of an improved rapid method for the quantification of arsenic species, including arsenite (As III ), arsenate (As V ), arsenocholine (AsC), arsenobetaine (AsB), dimethylarsinic acid (DMA), and monomethyl arsonic acid (MMA), in seaweed, sediment, and seawater samples using high-performance liquid chromatography/inductively coupled plasma-mass spectrometry (HPLC/ICP-MS). ICP-MS based on dynamic reaction cells was used to eliminate spectral interference. Ammonium nitrate- and phosphate-based eluents were used as the mobile phases for HPLC analysis, leading to shorter overall retention time (6 min) and improved peak separation. Arsenicals were extracted with a 1% HNO 3 solution that required no clean-up process and exhibited reasonable sensitivity and peak resolution. The optimized method was verified by applying it to hijiki seaweed certified reference material (CRM, NMIJ 7405-a) and to spiked blank samples of sediment and seawater. The proposed method measured the concentration of As V in the CRM as 9.6 ± 0.6 μg/kg dry weight (dw), which is close to the certified concentration (10.1 ± 0.5 μg/kg dw). The recovery of the six arsenicals was 87-113% for the sediment and 99-101% for the seawater. In the analysis of real samples, As V was the most abundant arsenical in hijiki and gulfweed, whereas AsB was dominant in other seaweed species. The two inorganic arsenicals (As III and As V ) and As V were the most dominant in the sediment and seawater samples, respectively.

Realgar (arsenic sulfide) is widely used in combination with other herbs as Chinese patent medicine to treat a variety of diseases in China. As a mineral arsenic, its mild toxicity was also well known. Longtime over-dose usage or wrongly oral intake of realgar can cause chronic arsenic poisoning and/or death, but acute fatal arsenic poisoning resulted from short-term dermal use of realgar-containing medicine was very rare. Here, we present the case of a 35-year-old Chinese man, who was diagnosed with severe psoriasis and died of fatal acute arsenic poisoning after he applied a local folk prescription ointment containing mainly the realgar to the affected skin for about 4 days. The autopsy showed multiple punctate hemorrhages over the limbs, pleural effusion, edematous lungs with consolidation, mild myocardial hypertrophy and normal-looking kidneys. The histopathological examination of renal tissue showed severe degeneration, necrosis and desquamation of renal tubular epithelial cells, presence of protein cast and a widened edematous interstitium with interstitial fibrosis. The presence of arsenic in large amount in the ointment (about 6%), in blood (1.76 μg/mL), and in skin (4.71 μg/g), were confirmed analytically. We also provide the clinical records of the deceased and briefly reviewed 7 similar cases in literature (6 in Chinese and 1 in English) in the past 30 years in China., (Copyright © 2019. Published by Elsevier B.V.)

Roxarsone (ROX), an organoarsenic feed additive, occurs as itself and its metabolites including As(V), As(III), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in animal manure. Animal manure improves soil biological property, whereas As compounds impact microorganisms. The integral influence of animal manure bearing ROX metabolites on soil biological quality is not clear yet. Herein, the effect of four chicken manures excreted by chickens fed with four diets containing 0, 40, 80 and 120 mg ROX kg -1 , on soil biological attributes. ROX addition in chicken diets increased total As and ROX metabolites in manures, but decreased manure total N, ammonium and nitrate. The elevated ROX metabolites in manures increased soil total As, As species and total N, and increased first and then decreased soil nitrate and nitrite, but did not affect soil ammonium in manure-applied soils. The promoting role of both soil As(III) and ammonium on soil microbial biomass carbon and nitrogen, respiration and saccharase activity, were exceeded or balanced by the inhibiting effect of soil nitrate. The suppression of soil catalase activity by soil As(V) was surpassed by the enhancement caused by soil nitrate and nitrite. Soil urease, acid phosphatase and polyphenol oxidase activities were not suitable bioindicators in the four manure-amended soils. Soil DMA did not affect soil biological properties, and MMA was not detectable in all manure-amended soils. The above highlights the complexity of joint influence of soil As and N on biological attributes. Totally, when ROX is used at allowable dose in chicken diet, soil biological quality would be suppressed in manure-amended soil., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The bioavailability of the metalloid arsenic (As) in paddy soil is controlled by microbial cycling of As and other elements such as iron (Fe) and sulfur (S), which are strongly influenced by water management in paddy fields. In this study, we evaluated how water management affects As bioavailability by growing rice plants in a geogenic As-contaminated soil. We determined As speciation in soil porewater and the diversity of the associated microbial community. Continuous flooding enhanced the release of Fe and As and increased arsenite (As(III)) and methylated As species concentrations in the rice grain compared with aerobic treatment. Total inorganic and organic As in the grain was 84% and 81% lower, respectively, in the aerobic treatment compared with the continuous flooding treatment. The amounts of Fe(III)-reducing bacteria (FeRB) increased in the flooded rhizosphere soil. The abundance of FeRB in the soil correlated with the dissolution of Fe and As. Among the As-transformation genes quantified, the aioA gene for As(III) oxidation and arsM gene for As(III) methylation were most abundant. The arsM copy number correlated positively with the levels of dsrB (dissimilatory (bi) sulfite reductase β-subunit), suggesting that dissimilatory sulfate-reducing bacteria (SRB) may play an important role in dimethylarsenate (DMAs(V)) production in soil. Our results show that decreased populations of rhizosphere FeRB and SRB contributed to a lower bioavailability of As, and decreased production of methylated arsenicals under oxic conditions., (Copyright © 2019. Published by Elsevier Ltd.)

Emet and Orhaneli stream basins are characterized by intense mining of colemanite, the main borate mineral in the area. Unlike other global borate deposits, the colemanite of this region contains arsenic minerals (realgar and orpiment). Undoubtedly, improper management of mine wastes causes pollution of water resources, affecting human life and biota. In the present study, spatial and temporal variation in water quality of Emet and Orhaneli streams was assessed. The water quality index (WQI) model was used to rate the overall status of the water, and geographical information systems (GIS) was used to aid the visualization of results. No significant differences in WQIs for the three-monitoring periods (March, July and October 2017) were noted. The WQI in the region is highly influenced by arsenic (As) and boron (B), with a strong positive correlation (p < 0.05, r 2  = 0.971). The As and B concentrations in Emet stream were 1.88-1907 μg/L and 0.01-1900 mg/L, respectively. Whereas for Orhaneli stream, respective As and B levels ranged from 5.17 to 116 μg/L and 0.01 to 5.45 mg/L. Globally, the As level in Emet stream basin is comparable to some of the words major contaminated regions such as Rapti River Basin (India) and Xieshui River (China). However, the uniqueness of this basin is seen in B and As trends, and input routes like active geothermal waters and weathering of the realgar (AsS) and orpiment (As 2 S 3 ) from colemanite nodules. This paper demonstrates the influence of pollutants associated with basin geochemistry and exploration of mineral resources on WQI.

A rapid and sensitive method was established for arsenic (As) speciation based on high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). This method was validated for the quantification of four arsenic species, including arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ) and dimethylarsinic acid (DMA V ) in cynomolgus macaque plasma. Separation was achieved in just 3.7 min with an alkyl reverse phase column and highly aqueous mobile phase containing 20 mM citric acid and 5 mM sodium hexanesulfonate (pH = 4.3). The calibration curves were linear over the range of 5⁻500 ng·mL -1 (measured as As), with r > 0.99. The above method was validated for selectivity, precision, accuracy, matrix effect, recovery, carryover effect and stability, and applied in a comparative pharmacokinetic study of arsenic species in cynomolgus macaque samples following intravenous and intragastrical administration of arsenic trioxide solution (0.80 mg·kg -1 ; 0.61 mg·kg -1 of arsenic); in addition, the absolute oral bioavailability of the active ingredient As III of arsenic trioxide in cynomolgus macaque samples was derived as 60.9 ± 16.1%.

Ophiocordyceps sinensis has been utilized in China and adjacent countries for thousands of years as a rare functional food to promote health and treat diverse chronic diseases. In recent years, adulterants are usually identified in the processed products of wild O. sinensis . However, the effective adulteration examination has to be additionally performed except their routine test, and accordingly is time- and money-consuming. Recently, arsenic determination has become a necessary test for confirming whether the concentrations of inorganic arsenic are over the O. sinensis limit. In this work, the contents of total arsenic and As species in cultivated O. sinensis, Cordyceps militaris , and other edible fungi were determined by ICP-MS and HPLC-ICP-MS. The results suggest that the As speciation exhibits a species-specific behavior, and accompanies the effect of the As background. The proportions of unknown organic As and contents of total As may be considered as sensitive markers for discriminating wild O. sinensis . This result provides a novel clue for discriminating wild and artificially cultivated mushrooms/their products, with emphasis on arsenic markers for authenticating wild O. sinensis .

Several extraction and chromatographic methods were evaluated to identify optimum conditions for arsenic speciation analysis in seafood and seaweed. The extraction systems, which include aqueous, aqueous-organic, acidic, basic, and enzymatic solutions, were examined for their efficiency in extracting arsenic from finfish, crustaceans, molluscs, and seaweed keeping the chemical forms of the native arsenicals intact. While dilute solutions of nitric acid, hydrochloric acid, and tetramethylammonium hydroxide (TMAH) extract high fractions of arsenic from most of the matrices, the extractants oxidized arsenite (As 3+ ) to arsenate (As 5+ ) and converted some arsenosugars and non-polar arsenicals to known and/or unknown forms. Hot water (90 °C) effectively maintained the integrity of the native arsenic species and enabled analysis of the extracts with no further manipulation than filtration and dilution. Stepwise extraction of water-soluble and non-polar arsenic with hot water and a mixture of dichloromethane and methanol, respectively, resulted in sufficiently quantitative (> 75%) arsenic extraction from seafood and seaweed. Anion and cation exchange chromatographic methods were optimized for separation and quantitation of the arsenicals extracted into hot water. The non-polar arsenicals were collectively determined after digesting the extract in acid. The application of the optimum extraction and chromatographic conditions was demonstrated by analyzing certified reference materials of tuna fish tissue (BCR 627), lobster hepatopancreas (TORT-2) and oyster tissue (SRM 1566b), and a sample of hijiki seaweed. For all the matrices, good agreement (80-92%) was found between the total water-soluble arsenic and the sum of the concentrations of the chromatographed species. Limits of quantification (LOQ) were in the range 4-11 ng g -1 for 16 arsenicals.

Single laboratory validation of a method for arsenic speciation analysis in seafood and seaweed is presented. The method is based on stepwise extraction of water-soluble and non-polar arsenic with hot water and a mixture of dichloromethane and methanol, respectively. While the water-soluble arsenicals were speciated by anion and cation exchange liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS), the non-polar arsenicals were collectively determined by ICP-MS after digestion in acid. The performance characteristics and broad application of the method were evaluated by analyzing eight commercial samples (cod, haddock, mackerel, crab, shrimp, geoduck clam, oyster, and kombu) and four reference materials (fish protein (DORM-4), lobster hepatopancreas (TORT-3), mussel tissue (SRM 2976), and hijiki seaweed (CRM 7405-a)) representing finfish, crustaceans, molluscs, and seaweed. Matrices spiked at three levels in duplicates were also analyzed. The stepwise extraction provided 76-106% extraction of the total arsenic from the test materials. The method demonstrated satisfactory repeatability for analysis of replicate extracts prepared over several days. The accuracy of the method was evaluated by analyzing reference materials certified for both total arsenic and a few arsenicals; the experimental results were 90-105% of the certified values. Comparison between the total water-soluble arsenic and the sum of the concentrations of the chromatographed species gave 80-92% mass balance. While spike recoveries of most arsenicals were in the acceptance range set by CODEX, a few species spiked into cod, haddock, and shrimp were poorly recovered due to transformation to other forms. After thorough investigations, strategies were devised to improve the recoveries of these species by averting their transformations. Limits of quantification (LOQ) for the extraction and quantification of 16 arsenicals using the current method were in the range 6-16 ng g -1 arsenic.

The bioaccumulation and biotransformation of arsenic (As) were studied in six representative marine sponges from the French Mediterranean and Irish Atlantic coasts. Methodologies were carefully optimized in one of the species on Haliclona fulva sponges for two critical steps: the sample mineralization for total As analysis by ICP-MS and the extraction of As species for HPLC-ICP-MS analysis. During the optimization, extractions performed with 0.6 mol L -1 H 3 PO 4 were shown to be the most efficient. Extraction recovery of 81% was obtained which represents the best results obtained until now in sponge samples. Total As analyses and As speciation were performed on certified reference materials and allow confirming the measurement quality both during the sample preparation and analysis. Additionally, this study represents an environmental survey demonstrating a high variability of total As concentrations among the different species, probably related to different physiological or microbial features. As speciation results showed the predominance of arsenobetaine (AsB) regardless of the sponge species, as well as the occurrence of low amounts of dimethylarsinic acid (DMA), arsenate (As(+V)), and unknown As species in some samples. The process responsible for As transformation in sponges is most likely related to sponges metabolism itself or the action of symbiont organisms. AsB is supposed to be implied in the protection against osmolytic stress. This study demonstrates the ability of sponges to accumulate and bio-transform As, proving that sponges are relevant bio-monitors for As contamination in the marine environment, and potential tools in environmental bio-remediation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Differences in the distribution, partitioning, and bioaccumulation characteristics of arsenicals between freshwater and saltwater systems remain poorly understood. To determine the characteristics of distribution and behavior of arsenicals, multimedia environmental samples including water, suspended particles, zooplankton, sediments, and porewater were collected from inner (five sites, freshwater) and outer (five sites, saltwater) regions of the estuary dike of the Youngsan River Estuary in South Korea (Nov., 2012). Six organic and inorganic forms of As were separated and measured using HPLC-ICP/MS equipped with an anion exchange column. Concentrations of arsenicals in water samples of the inner region (mean = 1.5 μg As L -1 ) were significantly lower than in those of the outer region (mean = 5.2 μg As L -1 ). Conversely, concentrations of As in suspended particles in the inner region (mean = 14 μg As g -1 ) were much greater than in the outer region (mean = 5.7 μg As g -1 ). The field-based distribution coefficient (K d ) for As depended strongly on salinity; relatively greater K d values were found in freshwater compared with saltwater. The As V was found to be the major form of As in all water and particle samples in both inner and outer regions. The zooplankton species were significantly distinguishable between the inner and outer regions; cladocerans were the most dominant species in freshwater and cyclopoida were predominantly found in saltwater. The As concentrations in zooplankton were shown to be particle-concentration dependent, suggesting that dietary exposure plays a substantial role in the bioaccumulation of As. Inorganic arsenicals, such as As V and As III were the most dominant forms found in zooplankton. Partitioning behavior of As between porewater and sediments was similar to that in water-particle distributions. The results of the present study enhance the understanding of As biogeochemistry in river and estuarine environments., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The controls on the mobility and fate of arsenic in lakes impacted by historical gold ore roasting in northern Canada have been examined. A detailed characterization of arsenic solid and aqueous phases in lake waters, lake sediments and sediment porewaters as well as surrounding soils was conducted in three small lakes (<200ha) downwind and within 5 km of the historic mining and roasting operations of Giant Mine (Northwest Territories). These lakes are marked by differing limnological characteristics such as area, depth and organic content. Radiometric age-dating shows that the occurrence of arsenic trioxide in lake sediments coincides with the regional onset of roasting activities. Quantification by advanced electron microscopy shows that arsenic trioxide accounts for up to 6 wt% of the total arsenic in sediments. The bulk (>80 wt%) of arsenic is contained in the form of secondary sulphide precipitates, with iron oxy-hydroxides hosting a minimal amount of arsenic (<1 wt%). Soluble arsenic trioxide particles act as the primary source of arsenic into sediment porewaters. Dissolved arsenic in reducing porewaters both precipitates in-situ as secondary sulphides, and diffuses upwards into the overlying lake waters. Geogenic arsenic phases are present in sediments in low concentrations and are not considered a significant source of arsenic to porewaters or lake waters. Sediment-water interface diffusive flux calculations suggest that the diffusion of dissolved arsenic from porewaters, combined with lake water residence time, are the predominant mechanisms controlling arsenic concentrations in lake waters., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Arsenic and its species were investigated for the first time in nine collections of Elaphomyces spp. ("deer truffles") from the Czech Republic with inductively coupled plasma mass spectrometry (ICPMS) and high-performance liquid chromatography coupled to ICPMS. The total arsenic concentrations ranged from 12 to 42 mg kg -1 dry mass in samples of E. asperulus and from 120 to 660 mg kg -1 dry mass in E. granulatus and E. muricatus. These concentrations are remarkably high for terrestrial organisms and demonstrate the arsenic-accumulating ability of these fungi. The dominating arsenic species in all samples was methylarsonic acid which accounted for more than 30% of the extractable arsenic. Arsenobetaine, dimethylarsinic acid, and inorganic arsenic were present as well, but only at trace concentrations. Surprisingly, we found high amounts of trimethylarsine oxide in all samples (0.32-28% of the extractable arsenic). Even more remarkable was that all but two samples contained significant amounts of the highly toxic trivalent arsenic compound methylarsonous acid (0.08-0.73% of the extractable arsenic). This is the first report of the occurrence of trimethylarsine oxide and methylarsonous acid at significant concentrations in a terrestrial organism. Our findings point out that there is still a lot to be understood about the biotransformation pathways of arsenic in the terrestrial environment. Graphical abstract Trimethylarsine oxide and methylarsonous acid in "deer truffles".

Basal autophagy has an indispensable role in the functioning and maintenance of cardiac geometry under physiological conditions. Recently, increasing evidence has demonstrated that arsenic (As)/copper (Cu) play important roles in the autophagy of the heart. The current study was to evaluate whether oxidative damage by As or/and Cu was correlated with autophagy through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in the heart of birds. Arsenic trioxide (30mg/kg) or/and cupric sulfate (300mg/kg) were administered in a basal diet to male Hy-line chickens (one-day-old) for 12 weeks. The results showed that heart weight/body weight ratio decreased in the As + Cu group only at 4, 8 and 12 weeks. Moreover, we observed that As or/and Cu decreased high-density lipoprotein cholesterol (HDL-C) concentrations, increased total cholesterol (T-CHO) concentrations and cardiac enzymes activities in the serum. On the other hand, As or/and Cu significantly reduced the activities of total antioxidant (T-AOC), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px)) along with decreased nonenzymic antioxidant (glutathione (GSH)) concentrations and increased malondialdehyde (MDA) concentrations in the heart. Furthermore, As or/and Cu could induce autophagy in the heart of chickens through decreased mRNA levels of TORC1, TORC2, microtubule associated light chains 3-I (LC3-I) and increased PI3K, AKT1, Beclin1, autophagy associated gene 4B (Atg4B), microtubule associated light chains 3-II (LC3-II), autophagy associated gene 5 (Atg5) and Dynein. Meanwhile, ultrastructural examinations showed that As/Cu could result in the appearance of autolygosomes, autophagic vacuoles and double-membrane structures in the heart. In conclusion, As or/and Cu induced cardiac damage and autophagy via elevating cardiac enzymes activities, inducing oxidative stress and activating the PI3K/AKT/mTORC pathway in heart of chickens. Moreover, As and Cu had a possible synergistic relationship in the heart of chickens., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Birds are at a higher level in the food chain; however, the potential bioaccumulation and biotransformation of arsenic (As) in birds in As mines has rarely been studied. In this study, four passerine bird species (tree sparrow [Passer montanus], light-vented bulbul [Pycnonotus sinensis], Garrulax canorus [Leucodioptron canorus], and magpie [Pica pica]) were collected from an abandoned As mine in China. The highest recorded As concentrations were 4.95 mg/kg and 51.65 mg/kg in muscles and feathers, respectively. Detection using high-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) revealed six As species, including arsenite (As(III)), arsenate (As(V)), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenobetaine (AsB) and arsenocholine (AsC), with the former three species as the dominant (>92%) and the latter three as the minor As species (<6.17%). Further analysis of the selected bird samples using the X-ray absorption near edge structure (XANES) technique revealed the existence of As(III)-tris-glutathione (As(III)-GSH), which can be regarded as equivalent to the non-extractable and unidentified As form in the HPLC-ICP-MS data. Both methods revealed similar patterns of As species in the birds from the As mine, with muscles containing mainly inorganic As and DMA and feathers containing mainly inorganic As. The results of this study contribute to the knowledge regarding As accumulation and speciation in terrestrial organisms., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Exposure to organophosphorus nerve agents, the most deadly chemical warfare agents, is possible in a variety of situations, such as destruction of chemical warfare agents, terrorist attacks, armed conflicts or accidents in research laboratories and storage facilities. Hundreds of thousands of tons of chemical munitions were disposed of at the sea in the post World War II period, with European, Russian, Japanese and US coasts being the most affected. Sulfur mustard, Lewisite and nerve agents appear to be the most frequently chemical warfare agents disposed of at the sea. Addressing the overall environmental risk, it has been one of the priorities of the world community since that time. Aside from confirming exposure to nerve agents in the alleged use for forensic purposes, the detection and identification of biological markers of exposure are also needed for the diagnosis and treatment of poisoning, in addition to occupational health monitoring for specific profiles of workers. When estimating detrimental effects of acute or potential chronic sub-lethal doses of organophosphorus nerve agents, released accidentally or intentionally into the environment, it is necessary to understand the wide spectra of physical, chemical and toxicological properties of these agents, and predict their ultimate fate in environmental systems., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Predicting the fates of arsenic (As) and selenium (Se) in natural geologic media like rocks and soils necessitates the understanding of how their various oxyanionic species behave and migrate under dynamic conditions. In this study, geochemical factors and processes crucial in the leaching and transport of arsenite (As III ), arsenate (As V ), selenite (Se IV ) and selenate (Se VI ) in tunnel-excavated rocks of marine origin were investigated using microscopic/extraction techniques, column experiments, dissolution-precipitation kinetics and one-dimensional reactive transport modeling. The results showed that evaporite salts were important because aside from containing As and Se, they played crucial roles in the evolution of pH and concentrations of coexisting ions, both of which had strong effects on adsorption-desorption reactions of As and Se species with iron oxyhydroxide minerals/phases. The observed leaching trends of As V , As III , Se IV and Se VI were satisfactorily simulated by one-dimensional reactive transport models, which predict that preferential adsorptions of As V and Se IV were magnified by geochemical changes in the columns due to water flow. Moreover, our results showed that migrations of As III , Se IV and Se VI could be predicted adequately by 1D solute transport with simple activity-K' d approach, but surface complexation was more reliable to simulate adsorption-desorption behavior of As V ., (Copyright © 2017 Elsevier Ltd. All rights reserved.)