SHRNA SILENCING OF AS3MT EXPRESSION MINIMIZES ARSENIC METHYLATION CAPACITY OF HEPG2 CELLS

EPA Science Inventory

Several methyltransferases have been shown to catalyze the oxidative methylation of inorganic arsenic (iAs) in mammalian species. However, the relative contributions of these enzymes to the overall capacity of cells to methylate iAs have not been characterized. Arsenic (+3 oxidat...

Arsenic Methylation Capacity and Metabolic Syndrome in the 2013–2014 U.S. National Health and Nutrition Examination Survey (NHANES)

PubMed Central

Pace, Clare; Smith-Gagen, Julie

2018-01-01

Arsenic methylation capacity is associated with metabolic syndrome and its components among highly exposed populations. However, this association has not been investigated in low to moderately exposed populations. Therefore, we investigated arsenic methylation capacity in relation to the clinical diagnosis of metabolic syndrome in a low arsenic exposure population. Additionally, we compared arsenic methylation patterns present in our sample to those of more highly exposed populations. Using logistic regression models adjusted for relevant biological and lifestyle covariates, we report no association between increased arsenic methylation and metabolic syndrome in a population in which arsenic is regulated at 10 ppb in drinking water. However, we cannot rule out the possibility of a positive association between arsenic methylation and metabolic syndrome in a subsample of women with normal body mass index (BMI). To our knowledge this is the first investigation of arsenic methylation capacity with respect to metabolic syndrome in a low exposure population. We also report that methylation patterns in our sample are similar to those found in highly exposed populations. Additionally, we report that gender and BMI significantly modify the effect of arsenic methylation on metabolic syndrome. Future studies should evaluate the effectiveness of arsenic policy enforcement on subclinical biomarkers of cardiovascular disease. PMID:29361794

XRCC1 Arg194Trp and Arg399Gln polymorphisms and arsenic methylation capacity are associated with urothelial carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiang, Chien-I; Huang, Ya-Li; Chen, Wei-Jen

The association between DNA repair gene polymorphisms and bladder cancer has been widely studied. However, few studies have examined the correlation between urothelial carcinoma (UC) and arsenic or its metabolites. The aim of this study was to examine the association between polymorphisms of the DNA repair genes, XRCC1 Arg194Trp, XRCC1 Arg399Gln, XRCC3 Thr241Met, and XPD Lys751Gln, with urinary arsenic profiles and UC. To this end, we conducted a hospital-based case–control study with 324 UC patients and 647 age- and gender-matched non-cancer controls. Genomic DNA was used to examine the genotype of XRCC1 Arg194Trp, XRCC1 Arg399Gln, XRCC3 Thr241Met, and XPD Lys751Glnmore » by PCR-restriction fragment length polymorphism analysis (PCR-RFLP). Urinary arsenic profiles were measured by high performance liquid chromatography (HPLC) linked with hydride generator and atomic absorption spectrometry. The XRCC1 399 Gln/Gln and 194 Arg/Trp and Trp/Trp genotypes were significantly related to UC, and the odds ratio (OR) and 95% confidence interval (95%CI) were 1.68 (1.03–2.75) and 0.66 (0.48–0.90), respectively. Participants with higher total urinary arsenic levels, a higher percentage of inorganic arsenic (InAs%) and a lower percentage of dimethylarsinic acid (DMA%) had a higher OR of UC. Participants carrying XRCC1 risk diplotypes G-C/G-C, A-C/A-C, and A-T/G-T, and who had higher total arsenic levels, higher InAs%, or lower DMA% compared to those with other XRCC1 diplotypes had a higher OR of UC. Our results suggest that the XRCC1 399 Gln/Gln and 194 Arg/Arg DNA repair genes play an important role in poor arsenic methylation capacity, thereby increasing the risk of UC in non-obvious arsenic exposure areas. - Highlights: • The XRCC1 399Gln/Gln genotype was significantly associated with increased OR of UC. • The XRCC1 194 Arg/Trp and Trp/Trp genotype had a significantly decreased OR of UC. • Combined effect of the XRCC1 genotypes and poor arsenic methylation

Genomic-wide analysis of BEAS-2B cells exposed to Trivalent Arsenicals and Dimethylthioarsinic acid

EPA Science Inventory

Lung is a major target for arsenic carcinogenesis in humans by both oral and inhalation routes. However, the carcinogenic mode of action of arsenicals is unknown. We investigated the effects of inorganic arsenic (iAsIII), monomethylarsonous acid (MMAIII), dimethylarsinous acid (D...

Interaction of plasma glutathione redox and folate deficiency on arsenic methylation capacity in Bangladeshi adults

PubMed Central

Niedzwiecki, Megan M.; Hall, Megan N.; Liu, Xinhua; Slavkovich, Vesna; Ilievski, Vesna; Levy, Diane; Alam, Shafiul; Siddique, Abu B.; Parvez, Faruque; Graziano, Joseph H.; Gamble, Mary V.

2014-01-01

Inorganic arsenic (InAs) is metabolized through a series of methylation reactions catalyzed by arsenic(III)-methyltransferase (AS3MT), resulting in the generation of monomethylarsonic (MMAs) and dimethylarsinic acids (DMAs). AS3MT activity requires the presence of the methyl donor S-adenosylmethionine (SAM), a product of folate-dependent one-carbon metabolism, and a reductant. Although glutathione (GSH), the primary endogenous antioxidant, is not required for As methylation, GSH stimulates As methylation rates in vitro. However, the relationship between GSH redox and As methylation capacity in humans is unknown. We wished to test the hypothesis that a more oxidized plasma GSH redox status is associated with decreased As methylation capacity, and examine whether these associations are modified by folate nutritional status. Concentrations of plasma GSH and GSSG, plasma folate, total blood As (bAs), total urinary As (uAs), and uAs metabolites were assessed in a cross-sectional study of n = 376 Bangladeshi adults who were chronically exposed to As in drinking water. We observed that a decreased plasma GSH/GSSG ratio (reflecting a more oxidized redox state) was significantly associated with increased urinary %MMA, decreased urinary %DMA, and increased total bAs in folate-deficient individuals (plasma folate ≤ 9.0 nmol/L). Concentrations of plasma GSH and GSSG were independently associated with increased and decreased As methylation capacity, respectively. No significant associations were observed in folate-sufficient individuals, and interactions by folate status were statistically significant. Our findings suggest that GSH/GSSG redox regulation might contribute to the large interindividual variation in As methylation capacity observed in human populations. PMID:24726863

PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

EPA Science Inventory

Plasmid DNA damage caused by methylated arsenicals, ascorbic acid and human liver ferritin.

Arsenic causes cancer in human skin, urinary bladder, lung, liver and kidney and is a significant world-wide public health problem. Although the metabolism of inorganic arsenic is ...

The influence of thermal treatment on bioweathering and arsenic sorption capacity of a natural iron (oxyhydr)oxide-based adsorbent.

PubMed

Debiec, Klaudia; Rzepa, Grzegorz; Bajda, Tomasz; Zych, Lukasz; Krzysztoforski, Jan; Sklodowska, Aleksandra; Drewniak, Lukasz

2017-12-01

Adsorption plays a significant role in remediation of waters contaminated with arsenic, but the efficiency of the process varies depending on the sorbent properties. Bog iron ores (BIOs), characterized by high sorption capacity and widespread availability, seem to be an optimal sorbent of arsenic. However, the use of BIOs for arsenic removal from waters may be limited by the high amount of organic matter, which may stimulate microbial activity, and thus decomposition of the sorbent. The aim of this study was to determine the effect of organic matter removal by thermal transformation (roasting) on the bioavailability of BIOs and their arsenic sorption capacity. For this purpose, the influence of bacterial growth and activity on untreated and treated BIOs, unloaded and loaded with arsenic, was studied. Moreover, the chemical and physical properties (including FTIR and desorption of arsenic) of BIOs were investigated as well. The results show that the removal of organic matter increases the stability of BIOs, and thus reduces the bioavailability of the immobilized arsenic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficient arsenic(V) removal from water by ligand exchange fibrous adsorbent.

PubMed

Awual, Md Rabiul; Shenashen, M A; Yaita, Tsuyoshi; Shiwaku, Hideaki; Jyo, Akinori

2012-11-01

This study is an efficient arsenic(V) removal from contaminated waters used as drinking water in adsorption process by zirconium(IV) loaded ligand exchange fibrous adsorbent. The bifunctional fibers contained both phosphonate and sulfonate groups. The bifunctional fiber was synthesised by graft polymerization of chloromethylstyrene onto polyethylene coated polypropylene fiber by means of electron irradiation graft polymerization technique and then desired phosphonate and sulfonate groups were introduced by Arbusov reaction followed by phosphorylation and sulfonation. Arsenic(V) adsorption was clarified in column methods with continuous flow operation in order to assess the arsenic(V) removal capacity in various conditions. The adsorption efficiency was evaluated in several parameters such as competing ions (chloride and sulfate), feed solution acidity, feed flow rate, feed concentration and kinetic performances at high feed flow rate of trace concentration arsenic(V). Arsenic(V) adsorption was not greatly changed when feed solutions pH at 3.0-7.0 and high breakthrough capacity was observed in strong acidic area below pH 2.2. Increasing the flow rate brings a decrease both breakthrough capacity and total adsorption. Trace level of arsenic(V) (0.015 mM) in presence of competing ions was also removed at high flow rate (750 h(-1)) with high removal efficiency. Therefore, the adsorbent is highly selective to arsenic(V) even in the presence of high concentration competing ions. The adsorbent is reversible and reusable in many cycles without any deterioration in its original performances. Therefore, Zr(IV) loaded ligand exchange adsorbent is to be an effective means to treat arsenic(V) contaminated water efficiently and able to safeguard the human health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genetic polymorphisms of PPAR gamma, arsenic methylation capacity and breast cancer risk in Mexican women.

PubMed

Pineda-Belmontes, Cristina P; Hernández-Ramírez, Raúl U; Hernández-Alcaraz, César; Cebrián, Mariano E; López-Carrillo, Lizbeth

2016-04-01

To evaluate whether the presence of polymorphisms of peroxisome proliferator-activated receptor gamma PPARγ (Pro 1 2Ala) and PPARGC1B (Ala203Pro) modifies the association between the inorganic arsenic (iAs) methylation capacity and breast cancer (BC). Mexican women were interviewed, and blood and urine samples were collected from them (cases/controls= 197/220). The concentration of urinary arsenic species and the polymorphisms of interest were determined by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and polymerase chain reaction (PCR), respectively. In women with a high %MMA (urinary monomethyl arsenic) and high primary methylation ratio (PM = MMA/iAs), the risk of BC was increased (odds ratio [OR]%MMA T3 vs.T1= 3.60: 95% confidence interval [CI] 2.02-6.41, ORPMI T3 vs.T1= 3.47: 95%CI 1.95-6.17), which was maintained after adjusting for polymorphisms. No significant interactions were observed between the polymorphisms and the arsenic variables on the risk of BC. Pro 12Ala and Ala203Pro polymorphisms did not modify the association between the iAs methylation capacity and BC.

A microbial arsenic cycle in sediments of an acidic mine impoundment: Herman Pit, Clear Lake, California

USGS Publications Warehouse

Blum, Jodi S.; McCann, Shelley; Bennett, S.; Miller, Laurence G.; Stolz, J. R.; Stoneburner, B.; Saltikov, C.; Oremland, Ronald S.

2015-01-01

The involvement of prokaryotes in the redox reactions of arsenic occurring between its +5 [arsenate; As(V)] and +3 [arsenite; As(III)] oxidation states has been well established. Most research to date has focused upon circum-neutral pH environments (e.g., freshwater or estuarine sediments) or arsenic-rich “extreme” environments like hot springs and soda lakes. In contrast, relatively little work has been conducted in acidic environments. With this in mind we conducted experiments with sediments taken from the Herman Pit, an acid mine drainage impoundment of a former mercury (cinnabar) mine. Due to the large adsorptive capacity of the abundant Fe(III)-rich minerals, we were unable to initially detect in solution either As(V) or As(III) added to the aqueous phase of live sediment slurries or autoclaved controls, although the former consumed added electron donors (i.e., lactate, acetate, hydrogen), while the latter did not. This prompted us to conduct further experiments with diluted slurries using the live materials from the first incubation as inoculum. In these experiments we observed reduction of As(V) to As(III) under anoxic conditions and reduction rates were enhanced by addition of electron donors. We also observed oxidation of As(III) to As(V) in oxic slurries as well as in anoxic slurries amended with nitrate. We noted an acid-tolerant trend for sediment slurries in the cases of As(III) oxidation (aerobic and anaerobic) as well as for anaerobic As(V) reduction. These observations indicate the presence of a viable microbial arsenic redox cycle in the sediments of this extreme environment, a result reinforced by the successful amplification of arsenic functional genes (aioA, and arrA) from these materials.

Experimental determination and modeling of arsenic complexation with humic and fulvic acids.

PubMed

Fakour, Hoda; Lin, Tsair-Fuh

2014-08-30

The complexation of humic acid (HA) and fulvic acid (FA) with arsenic (As) in water was studied. Experimental results indicate that arsenic may form complexes with HA and FA with a higher affinity for arsenate than for arsenite. With the presence of iron oxide based adsorbents, binding of arsenic to HA/FA in water was significantly suppressed, probably due to adsorption of As and HA/FA. A two-site ligand binding model, considering only strong and weak site types of binding affinity, was successfully developed to describe the complexation of arsenic on the two natural organic fractions. The model showed that the numbers of weak sites were more than 10 times those of strong sites on both HA and FA for both arsenic species studied. The numbers of both types of binding sites were found to be proportional to the HA concentrations, while the apparent stability constants, defined for describing binding affinity between arsenic and the sites, are independent of the HA concentrations. To the best of our knowledge, this is the first study to characterize the impact of HA concentrations on the applicability of the ligand binding model, and to extrapolate the model to FA. The obtained results may give insights on the complexation of arsenic in HA/FA laden groundwater and on the selection of more effective adsorption-based treatment methods for natural waters. Copyright © 2014 Elsevier B.V. All rights reserved.

SHRNA-MEDIATED SILENCING OF AS3MT EXPRESSION MODULATES THE CAPACITY OF HEPG2 CELLS TO METHYLATE INORGANIC ARSENIC

EPA Science Inventory

Several methyltransferases have been linked to the oxidative methylation of inorganic arsenic (iAs) in mammalian cells. However, the relative contributions of these enzymes to the overall capacity of cells to methylate iAs have not been characterized. Arsenic (+3 oxidation state)...

Nanostructural characterization of large-scale porous alumina fabricated via anodizing in arsenic acid solution

NASA Astrophysics Data System (ADS)

Akiya, Shunta; Kikuchi, Tatsuya; Natsui, Shungo; Suzuki, Ryosuke O.

2017-05-01

Anodizing of aluminum in an arsenic acid solution is reported for the fabrication of anodic porous alumina. The highest potential difference (voltage) without oxide burning increased as the temperature and the concentration of the arsenic acid solution decreased, and a high anodizing potential difference of 340 V was achieved. An ordered porous alumina with several tens of cells was formed in 0.1-0.5 M arsenic acid solutions at 310-340 V for 20 h. However, the regularity of the porous alumina was not improved via anodizing for 72 h. No pore sealing behavior of the porous alumina was observed upon immersion in boiling distilled water, and it may be due to the formation of an insoluble complex on the oxide surface. The porous alumina consisted of two different layers: a hexagonal alumina layer that contained arsenic from the electrolyte and a pure alumina honeycomb skeleton. The porous alumina exhibited a white photoluminescence emission at approximately 515 nm under UV irradiation at 254 nm.

GENE EXPRESSION PROFILING OF NORMAL HUMAN BRONCHIAL EPITHELIAL CELLS EXPOSED TO TRIVALENT ARSENICALS AND DIMETHYLTHIOARSINIC ACID

EPA Science Inventory

Lung is a major target for arsenic carcinogenesis in humans. However, the carcinogenic mode of action of arsenicals is unknown. We investigated, in human bronchial epithelial (BEAS2B) cells, the effects of inorganic arsenic (iAsIII), monomethylarsonous acid (MMAIII), dimethylarsi...

Microbial Community Structure and Arsenic Biogeochemistry in an Acid Vapor-Formed Spring in Tengchong Geothermal Area, China.

PubMed

Jiang, Zhou; Li, Ping; Jiang, Dawei; Dai, Xinyue; Zhang, Rui; Wang, Yanhong; Wang, Yanxin

2016-01-01

Arsenic biogeochemistry has been studied extensively in acid sulfate-chloride hot springs, but not in acid sulfate hot springs with low chloride. In this study, Zhenzhuquan in Tengchong geothermal area, a representative acid sulfate hot spring with low chloride, was chosen to study arsenic geochemistry and microbial community structure using Illumina MiSeq sequencing. Over 0.3 million 16S rRNA sequence reads were obtained from 6-paired parallel water and sediment samples along its outflow channel. Arsenic oxidation occurred in the Zhenxhuquan pool, with distinctly high ratios of arsenate to total dissolved arsenic (0.73-0.86). Coupled with iron and sulfur oxidation along the outflow channel, arsenic accumulated in downstream sediments with concentrations up to 16.44 g/kg and appeared to significantly constrain their microbial community diversity. These oxidations might be correlated with the appearance of some putative functional microbial populations, such as Aquificae and Pseudomonas (arsenic oxidation), Sulfolobus (sulfur and iron oxidation), Metallosphaera and Acidicaldus (iron oxidation). Temperature, total organic carbon and dissolved oxygen significantly shaped the microbial community structure of upstream and downstream samples. In the upstream outflow channel region, most microbial populations were microaerophilic/anaerobic thermophiles and hyperthermophiles, such as Sulfolobus, Nocardia, Fervidicoccus, Delftia, and Ralstonia. In the downstream region, aerobic heterotrophic mesophiles and thermophiles were identified, including Ktedonobacteria, Acidicaldus, Chthonomonas and Sphingobacteria. A total of 72.41-95.91% unassigned-genus sequences were derived from the downstream high arsenic sediments 16S rRNA clone libraries. This study could enable us to achieve an integrated understanding on arsenic biogeochemistry in acid hot springs.

PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

EPA Science Inventory

PLASMID DNA DAMAGE CAOUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

ABSTRACT

Both dimethylarsinic acid (DMA(V)) and dimethylarsinous acid (DMA(III)) release iron from human liver ferritin (HLF) with or without the presence of ascorbic acid. ...

Differential Effects of Low-Molecular-Weight Organic Acids on the Mobilization of Soil-Borne Arsenic and Trace Metals.

PubMed

Nworie, Obinna Elijah; Qin, Junhao; Lin, Chuxia

2017-08-21

A batch experiment was conducted to examine the effects of six low-molecular-weight organic acids on the mobilization of arsenic and trace metals from a range of contaminated soils. The results showed that the organic acids behaved differently when reacting with soil-borne As and trace metals. Oxalic acid and acetic acid had the strongest and weakest capacity to mobilize the investigated elements, respectively. The solubilisation of iron oxides by the organic acids appears to play a critical role in mobilizing other trace metals and As. Apart from acidification and complexation, reductive dissolution played a dominant role in the dissolution of iron oxides in the presence of oxalic acid, while acidification tended to be more important for dissolving iron oxides in the presence of other organic acids. The unique capacity of oxalic acid to solubilize iron oxides tended to affect the mobilization of other elements in different ways. For Cu, Mn, and Zn, acidification-driven mobilization was likely to be dominant while complexation might play a major role in Pb mobilization. The formation of soluble Fe and Pb oxalate complexes could effectively prevent arsenate or arsenite from combining with these metals to form solid phases of Fe or Pb arsenate or arsenite.

Combined Efficacy of Gallic Acid and MiADMSA with Limited Beneficial Effects Over MiADMSA Against Arsenic-induced Oxidative Stress in Mouse.

PubMed

Pachauri, Vidhu; Flora, Sjs

2015-01-01

Gallic acid is an organic acid known for its antioxidant and anticancer properties. The present study is focused on evaluating the role of gallic acid in providing better therapeutic outcomes against arsenic-induced toxicity. Animals pre-exposed to arsenic were treated with monoisoamyl meso-2,3-dimercaptosuccinic acid (MiADMSA), a new chelating drug, alone and in combination with gallic acid, consecutively for 10 days. The study suggests that (1) gallic acid in presence of MiADMSA is only moderately beneficial against arsenic, (2) monotherapy with gallic acid is more effective than in combination with MiADMSA after arsenic exposure in reducing oxidative injury, and (3) MiADMSA monotherapy as reported previously provides significant therapeutic efficacy against arsenic. Thus, based on the present results, we conclude that gallic acid is effective against arsenic-induced oxidative stress but provides limited additional beneficial effects when administered in combination with MiADMSA. We still recommend that lower doses of gallic acid be evaluated both individually and in combination with MiADMSA, as it might not exhibit the shortcomings we observed with higher doses in this study.

Microbial Community Structure and Arsenic Biogeochemistry in an Acid Vapor-Formed Spring in Tengchong Geothermal Area, China

PubMed Central

Jiang, Zhou; Li, Ping; Jiang, Dawei; Dai, Xinyue; Zhang, Rui; Wang, Yanhong; Wang, Yanxin

2016-01-01

Arsenic biogeochemistry has been studied extensively in acid sulfate-chloride hot springs, but not in acid sulfate hot springs with low chloride. In this study, Zhenzhuquan in Tengchong geothermal area, a representative acid sulfate hot spring with low chloride, was chosen to study arsenic geochemistry and microbial community structure using Illumina MiSeq sequencing. Over 0.3 million 16S rRNA sequence reads were obtained from 6-paired parallel water and sediment samples along its outflow channel. Arsenic oxidation occurred in the Zhenxhuquan pool, with distinctly high ratios of arsenate to total dissolved arsenic (0.73–0.86). Coupled with iron and sulfur oxidation along the outflow channel, arsenic accumulated in downstream sediments with concentrations up to 16.44 g/kg and appeared to significantly constrain their microbial community diversity. These oxidations might be correlated with the appearance of some putative functional microbial populations, such as Aquificae and Pseudomonas (arsenic oxidation), Sulfolobus (sulfur and iron oxidation), Metallosphaera and Acidicaldus (iron oxidation). Temperature, total organic carbon and dissolved oxygen significantly shaped the microbial community structure of upstream and downstream samples. In the upstream outflow channel region, most microbial populations were microaerophilic/anaerobic thermophiles and hyperthermophiles, such as Sulfolobus, Nocardia, Fervidicoccus, Delftia, and Ralstonia. In the downstream region, aerobic heterotrophic mesophiles and thermophiles were identified, including Ktedonobacteria, Acidicaldus, Chthonomonas and Sphingobacteria. A total of 72.41–95.91% unassigned-genus sequences were derived from the downstream high arsenic sediments 16S rRNA clone libraries. This study could enable us to achieve an integrated understanding on arsenic biogeochemistry in acid hot springs. PMID:26761709

Preserving the distribution of inorganic arsenic species in groundwater and acid mine drainage samples

USGS Publications Warehouse

Bednar, A.J.; Garbarino, J.R.; Ranville, J.F.; Wildeman, T.R.

2002-01-01

The distribution of inorganic arsenic species must be preserved in the field to eliminate changes caused by metal oxyhydroxide precipitation, photochemical oxidation, and redox reactions. Arsenic species sorb to iron and manganese oxyhydroxide precipitates, and arsenite can be oxidized to arsenate by photolytically produced free radicals in many sample matrices. Several preservatives were evaluated to minimize metal oxyhydroxide precipitation, such as inorganic acids and ethylenediaminetetraacetic acid (EDTA). EDTA was found to work best for all sample matrices tested. Storing samples in opaque polyethylene bottles eliminated the effects of photochemical reactions. The preservation technique was tested on 71 groundwater and six acid mine drainage samples. Concentrations in groundwater samples reached 720 ??g-As/L for arsenite and 1080 ??g-As/L for arsenate, and acid mine drainage samples reached 13 000 ??g-As/L for arsenite and 3700 ??g-As/L for arsenate. The arsenic species distribution in the samples ranged from 0 to 90% arsenite. The stability of the preservation technique was established by comparing laboratory arsenic speciation results for samples preserved in the field to results for subsamples speciated onsite. Statistical analyses indicated that the difference between arsenite and arsenate concentrations for samples preserved with EDTA in opaque bottles and field speciation results were analytically insignificant. The percentage change in arsenite:arsenate ratios for a preserved acid mine drainage sample and groundwater sample during a 3-month period was -5 and +3%, respectively.

Sex differences in the reduction of arsenic methylation capacity as a function of urinary total and inorganic arsenic in Mexican children.

PubMed

Torres-Sánchez, Luisa; López-Carrillo, Lizbeth; Rosado, Jorge L; Rodriguez, Valentina M; Vera-Aguilar, Eunice; Kordas, Katarzyna; García-Vargas, Gonzalo G; Cebrian, Mariano E

2016-11-01

Chronic arsenic (As) exposure decreases adult and children's ability to methylate inorganic As (iAs); however, few studies have examined children's sex differences. We measured urinary concentrations of iAs, monomethylarsonic (MMA), and dimethylarsinic (DMA) acids, and calculated the primary (PMI: MMA/iAs) and secondary (SMI: DMA/MMA) methylation capacity indexes in 591 children 6-8 years in Torreón, Mexico. We determined iAs, MMA, and DMA by hydride generation cryotrapping AAS. Lineal regression models estimated associations between methylation capacity and total As (TAs) or iAs. Interactions with sex were tested at p<0.10. Boys had significantly higher TAs levels, (58.4µg/L) than girls (46.2µg/L). We observed negative associations between TAs and PMI (β=-0.039; p<0.18) and SMI (β=-0.08; p=0.002) with significant sex differences; PMI reduction was significant in boys (β=-0.09; p=0.02) but not in girls (β=0.021; p=0.63), p for interaction=0.06. In contrast, SMI reduction was significantly more pronounced in girls. Furthermore, negative associations PMI (β=-0.19; p<0.001) and SMI (β=-0.35; p<0.001) were a function of urinary iAs levels, independently of TAs; however, the reduction in PMI was more pronounced in boys (β=-0.24; p<0.001; girls β=-0.15; p<0.001), p for interaction=0.04. A significant negative association was observed between SMI and iAs levels without significant sex differences. TAs and iAs associations with metabolite percentages were in good agreement with those observed with methylation indexes. Our results suggest that iAs plays an important role in reducing As methylation ability and that significant sex differences are present in As metabolism. These differences merit further investigation to confirm our findings and their potential implications for arsenic toxicity in children. Copyright © 2016 Elsevier Inc. All rights reserved.

Combined Efficacy of Gallic Acid and MiADMSA with Limited Beneficial Effects Over MiADMSA Against Arsenic-induced Oxidative Stress in Mouse

PubMed Central

Pachauri, Vidhu; Flora, SJS

2015-01-01

Gallic acid is an organic acid known for its antioxidant and anticancer properties. The present study is focused on evaluating the role of gallic acid in providing better therapeutic outcomes against arsenic-induced toxicity. Animals pre-exposed to arsenic were treated with monoisoamyl meso-2,3-dimercaptosuccinic acid (MiADMSA), a new chelating drug, alone and in combination with gallic acid, consecutively for 10 days. The study suggests that (1) gallic acid in presence of MiADMSA is only moderately beneficial against arsenic, (2) monotherapy with gallic acid is more effective than in combination with MiADMSA after arsenic exposure in reducing oxidative injury, and (3) MiADMSA monotherapy as reported previously provides significant therapeutic efficacy against arsenic. Thus, based on the present results, we conclude that gallic acid is effective against arsenic-induced oxidative stress but provides limited additional beneficial effects when administered in combination with MiADMSA. We still recommend that lower doses of gallic acid be evaluated both individually and in combination with MiADMSA, as it might not exhibit the shortcomings we observed with higher doses in this study. PMID:26339189

Arsenic speciation in hair and nails of acute promyelocytic leukemia (APL) patients undergoing arsenic trioxide treatment.

PubMed

Chen, Baowei; Cao, Fenglin; Lu, Xiufen; Shen, Shengwen; Zhou, Jin; Le, X Chris

2018-07-01

Arsenic in hair and nails has been used to assess chronic exposure of humans to environmental arsenic. However, it remains to be seen whether it is appropriate to evaluate acute exposure to sub-lethal doses of arsenic typically used in therapeutics. In this study, hair, fingernail and toenail samples were collected from nine acute promyelocytic leukemia (APL) patients who were administered intravenously the daily dose of 10 mg arsenic trioxide (7.5 mg arsenic) for up to 54 days. These hair and nail samples were analyzed for arsenic species using high performance liquid chromatography separation and inductively coupled plasma mass spectrometry detection (HPLC-ICPMS). Inorganic arsenite was the predominant form among water-extractable arsenicals. Dimethylarsinic acid (DMA V ), monomethylarsonic acid (MMA V ), monomethylarsonous acid (MMA III ), monomethylmonothioarsonic acid (MMMTA V ), and dimethylmonothioarsinic acid (DMMTA V ) were also detected in both hair and nail samples. This is the first report of the detection of MMA III and MMMTA V as metabolites of arsenic in hair and nails of APL patients. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of titanium dioxide in arsenic removal from water: A review.

PubMed

Guan, Xiaohong; Du, Juanshan; Meng, Xiaoguang; Sun, Yuankui; Sun, Bo; Hu, Qinghai

2012-05-15

Natural arsenic pollution is a global phenomenon and various technologies have been developed to remove arsenic from drinking water. The application of TiO(2) and TiO(2)-based materials in removing inorganic and organic arsenic was summarized. TiO(2)-based arsenic removal methods developed to date have been focused on the photocatalytic oxidation (PCO) of arsenite/organic arsenic to arsenate and adsorption of inorganic and organic arsenic. Many efforts have been taken to improve the performance of TiO(2) by either combing TiO(2) with adsorbents with good adsorption property in one system or developing bifunctional adsorbents with both great photocatalytic ability and high adsorption capacity. Attempts have also been made to immobilize fine TiO(2) particles on supporting materials like chitosan beads or granulate it to facilitate its separation from water. Among the anions commonly exist in groundwater, humic acid and bicarbonate have significant influence on TiO(2) photocatalyzed oxidation of As(III)/organic arsenic while phosphate, silicate, fluoride, and humic acid affect arsenic adsorption by TiO(2)-based materials. There has been a controversy over the TiO(2) PCO mechanisms of arsenite for the past 10 years but the adsorption mechanisms of inorganic and organic arsenic onto TiO(2)-based materials are relatively well established. Future needs in TiO(2)-based arsenic removal technology are proposed. Copyright © 2012 Elsevier B.V. All rights reserved.

A review on environmental factors regulating arsenic methylation in humans.

PubMed

Tseng, Chin-Hsiao

2009-03-15

Subjects exposed to arsenic show significant inter-individual variation in urinary patterns of arsenic metabolites but insignificant day-to-day intra-individual variation. The inter-individual variation in arsenic methylation can be partly responsible for the variation in susceptibility to arsenic toxicity. Wide inter-ethnic variation and family correlation in urinary arsenic profile suggest a genetic effect on arsenic metabolism. In this paper the environmental factors affecting arsenic metabolism are reviewed. Methylation capacity might reduce with increasing dosage of arsenic exposure. Furthermore, women, especially at pregnancy, have better methylation capacity than their men counterparts, probably due to the effect of estrogen. Children might have better methylation capacity than adults and age shows inconsistent relevance in adults. Smoking and alcohol consumption might be associated with a poorer methylation capacity. Nutritional status is important in the methylation capacity and folate may facilitate the methylation and excretion of arsenic. Besides, general health conditions and medications might influence the arsenic methylation capacity; and technical problems can cause biased estimates. The consumption of seafood, seaweed, rice and other food with high arsenic contents and the extent of cooking and arsenic-containing water used in food preparation may also interfere with the presentation of the urinary arsenic profile. Future studies are necessary to clarify the effects of the various arsenic metabolites including the trivalent methylated forms on the development of arsenic-induced human diseases with the consideration of the effects of confounding factors and the interactions with other effect modifiers.

Arsenic removal using natural biomaterial-based sorbents.

PubMed

Ansone, Linda; Klavins, Maris; Viksna, Arturs

2013-10-01

Arsenic contamination of water is a major problem worldwide. A possible solution can be approached through developing new sorbents based on cost-effective and environmentally friendly natural biomaterials. We have developed new sorbents based on biomaterial impregnation with iron oxyhydroxide. In this study, raw peat material, iron-modified peat, iron-modified biomass (shingles, straw, sands, cane and moss) as well as iron humate were used for the removal of arsenate from contaminated water. The highest sorption capacity was observed in iron-modified peat, and kinetic studies indicated that the amount of arsenic sorbed on this material exceeds 90 % in 5 h. Arsenate sorption on iron-modified peat is characterised by the pseudo-second-order mechanism. The results of arsenic sorption in the presence of competing substances indicated that sulphate, nitrate, chloride and tartrate anions have practically no influence on As(V) sorption onto Fe-modified peat, whereas the presence of phosphate ions and humic acid significantly lowers the arsenic removal efficiency.

Urinary arsenic species, toenail arsenic, and arsenic intake estimates in a Michigan population with low levels of arsenic in drinking water.

PubMed

Rivera-Núñez, Zorimar; Meliker, Jaymie R; Meeker, John D; Slotnick, Melissa J; Nriagu, Jerome O

2012-01-01

The large disparity between arsenic concentrations in drinking water and urine remains unexplained. This study aims to evaluate predictors of urinary arsenic in a population exposed to low concentrations (≤50 μg/l) of arsenic in drinking water. Urine and drinking water samples were collected from a subsample (n=343) of a population enrolled in a bladder cancer case-control study in southeastern Michigan. Total arsenic in water and arsenic species in urine were determined using ICP-MS: arsenobetaine (AsB), arsenite (As[III]), arsenate (As[V]), methylarsenic acid (MMA[V]), and dimethylarsenic acid (DMA[V]). The sum of As[III], As[V], MMA[V], and DMA[V] was denoted as SumAs. Dietary information was obtained through a self-reported food intake questionnaire. Log(10)-transformed drinking water arsenic concentration at home was a significant (P<0.0001) predictor of SumAs (R(2)=0.18). Associations improved (R(2)=0.29, P<0.0001) when individuals with less than 1 μg/l of arsenic in drinking water were removed and further improved when analyses were applied to individuals who consumed amounts of home drinking water above the median volume (R(2)=0.40, P<0.0001). A separate analysis indicated that AsB and DMA[V] were significantly correlated with fish and shellfish consumption, which may suggest that seafood intake influences DMA[V] excretion. The Spearman correlation between arsenic concentration in toenails and SumAs was 0.36 and between arsenic concentration in toenails and arsenic concentration in water was 0.42. Results show that arsenic exposure from drinking water consumption is an important determinant of urinary arsenic concentrations, even in a population exposed to relatively low levels of arsenic in drinking water, and suggest that seafood intake may influence urinary DMA[V] concentrations.

Arsenic Metabolites, Including N-Acetyl-4-hydroxy-m-arsanilic Acid, in Chicken Litter from a Roxarsone-Feeding Study Involving 1600 Chickens.

PubMed

Yang, Zonglin; Peng, Hanyong; Lu, Xiufen; Liu, Qingqing; Huang, Rongfu; Hu, Bin; Kachanoski, Gary; Zuidhof, Martin J; Le, X Chris

2016-07-05

The poultry industry has used organoarsenicals, such as 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, ROX), to prevent disease and to promote growth. Although previous studies have analyzed arsenic species in chicken litter after composting or after application to agricultural lands, it is not clear what arsenic species were excreted by chickens before biotransformation of arsenic species during composting. We describe here the identification and quantitation of arsenic species in chicken litter repeatedly collected on days 14, 24, 28, 30, and 35 of a Roxarsone-feeding study involving 1600 chickens of two strains. High performance liquid chromatography separation with simultaneous detection by both inductively coupled plasma mass spectrometry and electrospray ionization tandem mass spectrometry provided complementary information necessary for the identification and quantitation of arsenic species. A new metabolite, N-acetyl-4-hydroxy-m-arsanilic acid (N-AHAA), was identified, and it accounted for 3-12% of total arsenic. Speciation analyses of litter samples collected from ROX-fed chickens on days 14, 24, 28, 30, and 35 showed the presence of N-AHAA, 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA), inorganic arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA(V)), dimethylarsinic acid (DMA(V)), and ROX. 3-AHPAA accounted for 3-19% of the total arsenic. Inorganic arsenicals (the sum of As(III) and As(V)) comprised 2-6% (mean 3.5%) of total arsenic. Our results on the detection of inorganic arsenicals, methylarsenicals, 3-AHPAA, and N-AHAA in the chicken litter support recent findings that ROX is actually metabolized by the chicken or its gut microbiome. The presence of the toxic metabolites in chicken litter is environmentally relevant as chicken litter is commonly used as fertilizer.

Tannic acid for remediation of historically arsenic-contaminated soils.

PubMed

Gusiatin, Zygmunt Mariusz; Klik, Barbara; Kulikowska, Dorota

2017-12-22

Soil washing effectively and permanently decreases soil pollution. Thus, it can be considered for the removal of the most toxic elements, for example arsenic (As). In this study, historically As-contaminated soils (2041-4294 mg/kg) were remediated with tannic acid (TA) as the washing agent. The scope of this study included optimization of the operational conditions of As removal, determination of As distribution in soil before and after double soil washing, and measurement of TA loss during washing. The optimum conditions for As removal were 4% TA, pH 4 and 24 h washing time. The average As removal after single and double washings was 38% and 63%, respectively. TA decreased As content in amorphous and poorly crystalline oxides by >90%. Although TA increased the amount of As in the easily mobilizable As fraction, the stability of As in washed soils increased, with reduced partition indexes of 0.52-0.66 after washing. The maximum capacity of the soils to adsorb TA (q max ) was 50.2-70.4 g C/kg. TA sorption was higher at alkaline than at acidic conditions. Only TA removes As from soils effectively if the proportion of As in amorphous and poorly crystalline oxides is high. Thus, it can be considered for remediation of historically contaminated soils.

Evaluating of arsenic(V) removal from water by weak-base anion exchange adsorbents.

PubMed

Awual, M Rabiul; Hossain, M Amran; Shenashen, M A; Yaita, Tsuyoshi; Suzuki, Shinichi; Jyo, Akinori

2013-01-01

Arsenic contamination of groundwater has been called the largest mass poisoning calamity in human history and creates severe health problems. The effective adsorbents are imperative in response to the widespread removal of toxic arsenic exposure through drinking water. Evaluation of arsenic(V) removal from water by weak-base anion exchange adsorbents was studied in this paper, aiming at the determination of the effects of pH, competing anions, and feed flow rates to improvement on remediation. Two types of weak-base adsorbents were used to evaluate arsenic(V) removal efficiency both in batch and column approaches. Anion selectivity was determined by both adsorbents in batch method as equilibrium As(V) adsorption capacities. Column studies were performed in fixed-bed experiments using both adsorbent packed columns, and kinetic performance was dependent on the feed flow rate and competing anions. The weak-base adsorbents clarified that these are selective to arsenic(V) over competition of chloride, nitrate, and sulfate anions. The solution pH played an important role in arsenic(V) removal, and a higher pH can cause lower adsorption capacities. A low concentration level of arsenic(V) was also removed by these adsorbents even at a high flow rate of 250-350 h(-1). Adsorbed arsenic(V) was quantitatively eluted with 1 M HCl acid and regenerated into hydrochloride form simultaneously for the next adsorption operation after rinsing with water. The weak-base anion exchange adsorbents are to be an effective means to remove arsenic(V) from drinking water. The fast adsorption rate and the excellent adsorption capacity in the neutral pH range will render this removal technique attractive in practical use in chemical industry.

An investigation of the health effects caused by exposure to arsenic from drinking water and coal combustion: arsenic exposure and metabolism.

PubMed

Wei, Binggan; Yu, Jiangping; Kong, Chang; Li, Hairong; Yang, Linsheng; Guo, Zhiwei; Cui, Na; Xia, Yajuan; Wu, Kegong

2017-11-01

Few studies have been conducted to compare arsenic exposure, metabolism, and methylation in populations exposed to arsenic in drinking water and from coal combustion. Therefore, arsenic concentrations in the environment and arsenic speciation in the urine of subjects exposed to arsenic as a consequence of coal combustion in a rural area in Shaanxi province (CCA) and in drinking water in a rural area in Inner Mongolia (DWA) were investigated. The mean arsenic concentrations in drinking water, indoor air, and soil in CCA were 4.52 μg/L, 0.03 mg/m 3 , and 14.93 mg/kg, respectively. The mean arsenic concentrations in drinking water and soil in DWA were 144.71 μg/L and 10.19 mg/kg, respectively, while the level in indoor air was lower than the limit of detection. The total daily intakes of arsenic in DWA and CCA were 4.47 and 3.13 μg/day·kg, respectively. The mean urinary concentrations of inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and total arsenic (TAs) for subjects with skin lesions in DWA were 50.41, 47.01, 202.66, and 300.08 μg/L. The concentrations for subjects without skin lesions were 49.76, 44.20, 195.60, and 289.56 μg/L, respectively. The %iAs, %MMA, and %DMA in the TAs in the urine of subjects from CCA were 12.24, 14.73, and 73.03%, while the corresponding values from DWA were 17.54, 15.57, and 66.89%, respectively. The subjects in DWA typically had a higher %iAs and %MMA, and a lower %DMA, and primary and secondary methylation index (PMI and SMI) than the subjects in CCA. It was concluded that the arsenic methylation efficiency of subjects in DWA and CCA was significantly influenced by chronic exposure to high levels of arsenic in the environment. The lower PMI and SMI values in DWA revealed lower arsenic methylation capacity due to ingestion of arsenic in drinking water. However, it remained unclear if the differences in arsenic metabolism between the two groups were due to differences in exposure levels

Copper tolerance of brown-rot fungi : oxalic acid production in southern pine treated with arsenic-free preservatives

Treesearch

Frederick Green; Carol A. Clausen

2005-01-01

The voluntary withdrawal of chromated copper arsenate (CCA)-treated wood from most residential applications has increased the use of non-arsenical copper-based organic wood preservatives. Because the arsenic component of CCA controlled copper tolerant fungi, scientists have renewed interest in and concern about the decay capacity in the important copper-tolerant group...

Field Deployable Method for Arsenic Speciation in Water.

PubMed

Voice, Thomas C; Flores Del Pino, Lisveth V; Havezov, Ivan; Long, David T

2011-01-01

Contamination of drinking water supplies by arsenic is a world-wide problem. Total arsenic measurements are commonly used to investigate and regulate arsenic in water, but it is well understood that arsenic occurs in several chemical forms, and these exhibit different toxicities. It is problematic to use laboratory-based speciation techniques to assess exposure as it has been suggested that the distribution of species is not stable during transport in some types of samples. A method was developed in this study for the on-site speciation of the most toxic dissolved arsenic species: As (III), As (V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA). Development criteria included ease of use under field conditions, applicable at levels of concern for drinking water, and analytical performance.The approach is based on selective retention of arsenic species on specific ion-exchange chromatography cartridges followed by selective elution and quantification using graphite furnace atomic absorption spectroscopy. Water samples can be delivered to a set of three cartridges using either syringes or peristaltic pumps. Species distribution is stable at this point, and the cartridges can be transported to the laboratory for elution and quantitative analysis. A set of ten replicate spiked samples of each compound, having concentrations between 1 and 60 µg/L, were analyzed. Arsenic recoveries ranged from 78-112 % and relative standard deviations were generally below 10%. Resolution between species was shown to be outstanding, with the only limitation being that the capacity for As (V) was limited to approximately 50 µg/L. This could be easily remedied by changes in either cartridge design, or the extraction procedure. Recoveries were similar for two spiked hard groundwater samples indicating that dissolved minerals are not likely to be problematic. These results suggest that this methodology can be use for analysis of the four primary arsenic species of concern in

Field Deployable Method for Arsenic Speciation in Water

PubMed Central

Voice, Thomas C.; Flores del Pino, Lisveth V.; Havezov, Ivan; Long, David T.

2010-01-01

Contamination of drinking water supplies by arsenic is a world-wide problem. Total arsenic measurements are commonly used to investigate and regulate arsenic in water, but it is well understood that arsenic occurs in several chemical forms, and these exhibit different toxicities. It is problematic to use laboratory-based speciation techniques to assess exposure as it has been suggested that the distribution of species is not stable during transport in some types of samples. A method was developed in this study for the on-site speciation of the most toxic dissolved arsenic species: As (III), As (V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA). Development criteria included ease of use under field conditions, applicable at levels of concern for drinking water, and analytical performance. The approach is based on selective retention of arsenic species on specific ion-exchange chromatography cartridges followed by selective elution and quantification using graphite furnace atomic absorption spectroscopy. Water samples can be delivered to a set of three cartridges using either syringes or peristaltic pumps. Species distribution is stable at this point, and the cartridges can be transported to the laboratory for elution and quantitative analysis. A set of ten replicate spiked samples of each compound, having concentrations between 1 and 60 µg/L, were analyzed. Arsenic recoveries ranged from 78–112 % and relative standard deviations were generally below 10%. Resolution between species was shown to be outstanding, with the only limitation being that the capacity for As (V) was limited to approximately 50 µg/L. This could be easily remedied by changes in either cartridge design, or the extraction procedure. Recoveries were similar for two spiked hard groundwater samples indicating that dissolved minerals are not likely to be problematic. These results suggest that this methodology can be use for analysis of the four primary arsenic species of concern in

Arsenic methylation and skin lesions in migrant and native adult women with chronic exposure to arsenic from drinking groundwater.

PubMed

Wei, Binggan; Yu, Jiangping; Yang, Linsheng; Li, Hairong; Chai, Yuanqing; Xia, Yajuan; Wu, Kegong; Gao, Jianwei; Guo, Zhiwei; Cui, Na

2017-02-01

In order to figure out the prevalence of skin lesions and methylation capacity for migrant and native adult women in an endemic area for arsenic poisoning in Inner Mongolia, China, 207 adult women were selected for study subjects. The results showed that the prevalence of skin lesions for the external group, provincial group and native group was 36.54, 26.15 and 35.56 %, respectively. The nail content of arsenic and urinary concentrations of dimethylarsenic (DMA), monomethylarsenic (MMA) and inorganic arsenic (iAs) were significantly higher in women with skin lesions than in those without skin lesions. The highest urinary concentrations of DMA, MMA and iAs were 213.93, 45.72 and 45.01 μg/L in the native group. The arsenic methylation capacity index revealed that the external group had the greatest capacity, while the native group had the lowest. The odds ratios of skin lesions in relation to arsenic metabolites and arsenic methylation capacity varied widely among the three groups. Urinary MMA and iAs concentrations were positively associated with risk of skin lesions in the three groups of adult women, while primary and secondary methylation capacities were negatively related to risk of skin lesions in native and provincial groups. The external group might be more susceptible to MMA and iAs, while the provincial and native groups were more tolerance to MMA and iAs. Lower primary and secondary arsenic methylation capacities increased the risk of skin lesions in native and provincial groups. Moreover, higher nail arsenic concentration increased the risk of skin lesions of adult women.

Alpha-lipoic acid protects oxidative stress, changes in cholinergic system and tissue histopathology during co-exposure to arsenic-dichlorvos in rats.

PubMed

Dwivedi, Nidhi; Flora, Govinder; Kushwaha, Pramod; Flora, Swaran J S

2014-01-01

We investigated protective efficacy of α-lipoic acid (LA), an antioxidant against arsenic and DDVP co-exposed rats. Biochemical variables suggestive of oxidative stress, neurological dysfunction, and tissue histopathological alterations were determined. Male rats were exposed either to 50 ppm sodium arsenite in drinking water or in combination with DDVP (4 mg/kg, subcutaneously) for 10 weeks. α-Lipoic acid (50mg/kg, pos) was also co-administered in above groups. Arsenic exposure led to significant oxidative stress along, hepatotoxicity, hematotoxicity and altered brain biogenic amines levels accompanied by increased arsenic accumulation in blood and tissues. These altered biochemical variables were supported by histopathological examinations leading to oxidative stress and cell death. These biochemical alterations were significantly restored by co-administration of α-lipoic acid with arsenic and DDVP alone and concomitantly. The results indicate that arsenic and DDVP induced oxidative stress and cholinergic dysfunction can be significantly protected by the supplementation of α-lipoic acid. Copyright © 2013 Elsevier B.V. All rights reserved.

Elevated levels of plasma uric acid and its relation to hypertension in arsenic-endemic human individuals in Bangladesh

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huda, Nazmul; Department of Medicine, Rajshahi Medical College, Rajshahi 6000; Hossain, Shakhawoat

Blood uric acid has been recognized as a putative marker for cardiovascular diseases (CVDs). CVDs are the major causes of arsenic-related morbidity and mortality. However, the association of arsenic exposure with plasma uric acid (PUA) levels in relation to CVDs has not yet been explored. This study for the first time demonstrated the associations of arsenic exposure with PUA levels and its relationship with hypertension. A total of 483 subjects, 322 from arsenic-endemic and 161 from non-endemic areas in Bangladesh were recruited as study subjects. Arsenic concentrations in the drinking water, hair and nails of the study subjects were measuredmore » by inductively coupled plasma mass spectroscopy. PUA levels were measured using a colorimetric method. We found that PUA levels were significantly (p < 0.001) higher in males and females living in arsenic-endemic areas than those in non-endemic area. Arsenic exposure (water, hair and nail arsenic) levels showed significant positive correlations with PUA levels. In multiple regression analyses, arsenic exposure levels were found to be the most significant contributors on PUA levels among the other variables that included age, body mass index, blood urea nitrogen, and smoking. There were dose–response relationships between arsenic exposure and PUA levels. Furthermore, diastolic and systolic blood pressure showed significant positive correlations with PUA levels. Finally, the average PUA levels were significantly higher in the hypertensive group than those in the normotensive group in both males and females living in arsenic-endemic areas. These results suggest that arsenic exposure-related elevation of PUA levels may be implicated in arsenic-induced CVDs. - Highlights: • PUA levels were higher in arsenic-endemic subjects than in non-endemic subjects. • Drinking water, hair and nail arsenic showed significant associations with PUA levels. • Drinking water, hair and nail arsenic showed dose�

Bacteria-mediated arsenic oxidation and reduction in the growth media of arsenic hyperaccumulator Pteris vittata.

PubMed

Wang, Xin; Rathinasabapathi, Bala; de Oliveira, Letuzia Maria; Guilherme, Luiz R G; Ma, Lena Q

2012-10-16

Microbes play an important role in arsenic transformation and cycling in the environment. Microbial arsenic oxidation and reduction were demonstrated in the growth media of arsenic hyperaccumulator Pteris vittata L. All arsenite (AsIII) at 0.1 mM in the media was oxidized after 48 h incubation. Oxidation was largely inhibited by antibiotics, indicating that bacteria played a dominant role. To identify AsIII oxidizing bacteria, degenerate primers were used to amplify ∼500 bp of the AsIII oxidase gene aioA (aroA) using DNA extracted from the media. One aioA (aroA)-like sequence (MG-1, tentatively identified as Acinetobacter sp.) was amplified, exhibiting 82% and 91% identity in terms of gene and deduced protein sequence to those from Acinetobacter sp. 33. In addition, four bacterial strains with different arsenic tolerance were isolated and identified as Comamonas sp.C-1, Flavobacterium sp. C-2, Staphylococcus sp. C-3, and Pseudomonas sp. C-4 using carbon utilization, fatty acid profiles, and/or sequencing 16s rRNA gene. These isolates exhibited dual capacity for both AsV reduction and AsIII oxidation under ambient conditions. Arsenic-resistant bacteria with strong AsIII oxidizing ability may have potential to improve bioremediation of AsIII-contaminated water using P. vittata and/or other biochemical strategies.

Arsenic Transport and Transformation Associated with MSMA Application on a Golf Course Green

PubMed Central

Feng, Min; Schrlau, Jill E.; Snyder, Raymond; Snyder, George H.; Chen, Ming; Cisar, John L.; Cai, Yong

2008-01-01

The impact of extensively used arsenic-containing herbicides on groundwater beneath golf courses has become a topic of interest. Although currently used organoarsenicals are less toxic, their application into the environment may produce the more toxic inorganic arsenicals. The objective of this work was to understand the behavior of arsenic species in percolate water from monosodium methanearsonate (MSMA) applied golf course greens, as well as to determine the influences of root-zone media for United State Golf Association (USGA) putting green construction on arsenic retention and species conversion. The field test was established at the Fort Lauderdale Research and Education Center (FLREC), University of Florida. Percolate water was collected after MSMA application for speciation and total arsenic analyses. The results showed that the substrate composition significantly influenced arsenic mobility and arsenic species transformation in the percolate water. In comparison to uncoated sands (S) and uncoated sands and peat (S + P), naturally coated sands and peat (NS + P) showed a higher capacity of preventing arsenic from leaching into percolate water, implying that the coatings of sands with clay reduce arsenic leaching. Arsenic species transformation occurred in soil, resulting in co-occurrence of four arsenic species, arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in percolate water. The results indicated that substrate composition can significantly affect both arsenic retention in soil and arsenic speciation in percolate water. The clay coatings on the soil particles and the addition of peat in the soil changed the arsenic bioavailability, which in turn controlled the microorganism-mediated arsenic transformation. To better explain and understand arsenic transformation and transport after applying MSMA in golf green, a conceptual model was proposed. PMID:15853401

Folic acid protects against arsenic-mediated embryo toxicity by up-regulating the expression of Dvr1

PubMed Central

Ma, Yan; Zhang, Chen; Gao, Xiao-Bo; Luo, Hai-Yan; Chen, Yang; Li, Hui-hua; Ma, Xu; Lu, Cai-Ling

2015-01-01

As a nutritional factor, folic acid can prevent cardiac and neural defects during embryo development. Our previous study showed that arsenic impairs embryo development by down-regulating Dvr1/GDF1 expression in zebrafish. Here, we investigated whether folic acid could protect against arsenic-mediated embryo toxicity. We found that folic acid supplementation increases hatching and survival rates, decreases malformation rate and ameliorates abnormal cardiac and neural development of zebrafish embryos exposed to arsenite. Both real-time PCR analysis and whole in-mount hybridization showed that folic acid significantly rescued the decrease in Dvr1 expression caused by arsenite. Subsequently, our data demonstrated that arsenite significantly decreased cell viability and GDF1 mRNA and protein levels in HEK293ET cells, while folic acid reversed these effects. Folic acid attenuated the increase in subcellular reactive oxygen species (ROS) levels and oxidative adaptor p66Shc protein expression in parallel with the changes in GDF1 expression and cell viability. P66Shc knockdown significantly inhibited the production of ROS and the down-regulation of GDF1 induced by arsenite. Our data demonstrated that folic acid supplementation protected against arsenic-mediated embryo toxicity by up-regulating the expression of Dvr1/GDF1, and folic acid enhanced the expression of GDF1 by decreasing p66Shc expression and subcellular ROS levels. PMID:26537450

Adsorption of arsenic from aqueous solution using magnetic graphene oxide

NASA Astrophysics Data System (ADS)

Sherlala, A. I. A.; Raman, A. A.; Bello, M. M.

2017-06-01

A binary of graphene oxide (GO) and iron oxide (IO) was prepared and used for the removal of arsenic from aqueous solution. The synthesized compound was characterized using XRD analysis. The prepared composite was used for the adsorption of arsenic from aqueous solution. Central Composite Design was used to design the adsorption experiments and to investigate the effects of operational parameters (initial concentration of arsenic, adsorbent dosage, pH and time) on the adsorption capacity and efficiency. The adsorbent shows a high adsorption capacity for the arsenic. The adsorption efficiency ranges between 33.2 % and 99.95 %. The most significant factors affecting the adsorption capacity were found to be the initial concentration of arsenic and the adsorbent dosage. The initial pH of the solution slightly affects the adsorption capacity, with the maximum adsorption capacity occurring around pH 6 - 7. Thus, the developed adsorbent has a potential for effective removal of arsenic from aqueous solution.

Effects of iron on arsenic speciation and redox chemistry in acid mine water

USGS Publications Warehouse

Bednar, A.J.; Garbarino, J.R.; Ranville, J.F.; Wildeman, T.R.

2005-01-01

Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining-influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not always hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides deplete iron from some systems, and also affect arsenite and arsenate concentrations through sorption processes. ?? 2004 Elsevier B.V. All rights reserved.

A Phytoremediation Strategy for Arsenic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meagher, Richard B.

A Phytoremediation Strategy for Arsenic Progress Report May, 2005 Richard B. Meagher Principal Investigator Arsenic pollution affects the health of several hundred millions of people world wide, and an estimated 10 million Americans have unsafe levels of arsenic in their drinking water. However, few environmentally sound remedies for cleaning up arsenic contaminated soil and water have been proposed. Phytoremediation, the use of plants to extract and sequester environmental pollutants, is one new technology that offers an ecologically sound solution to a devastating problem. We propose that it is less disruptive to the environment to harvest and dispose of several thousandmore » pounds per acre of contaminated aboveground plant material, than to excavate and dispose of 1 to 5 million pounds of contaminated soil per acre (assumes contamination runs 3 ft deep). Our objective is to develop a genetics-based phytoremediation strategy for arsenic removal that can be used in any plant species. This strategy requires the enhanced expression of several transgenes from diverse sources. Our working hypothesis is that organ-specific expression of several genes controlling the transport, electrochemical state, and binding of arsenic will result in the efficient extraction and hyperaccumulation of arsenic into aboveground plant tissues. This hypothesis is supported by theoretical arguments and strong preliminary data. We proposed six Specific Aims focused on testing and developing this arsenic phytoremediation strategy. During the first 18 months of the grant we made significant progress on five Specific Aims and began work on the sixth as summarized below. Specific Aim 1: Enhance plant arsenic resistance and greatly expand sinks for arsenite by expressing elevated levels of thiol-rich, arsenic-binding peptides. Hyperaccumulation of arsenic depends upon making plants that are both highly tolerant to arsenic and that have the capacity to store large amounts of arsenic

Adsorption and reaction mechanism of arsenic vapors over γ-Al2O3 in the simulated flue gas containing acid gases.

PubMed

Hu, Hongyun; Chen, Dunkui; Liu, Huan; Yang, Yuhan; Cai, Hexun; Shen, Junhao; Yao, Hong

2017-08-01

Arsenic emission from fuel combustion and metal smelting flue gas causes serious pollution. Addition of sorbents is a promising way for the arsenic capture from high temperature flue gas. However, it is difficult to remove arsenic from SO 2 /HCl-rich flue gas due to the competitive reaction of the sorbents with arsenic and these acid gases. To solve this problem, arsenic adsorption over γ-Al 2 O 3 was studied in this work to evaluate its adsorption mechanism, resistance to acid gases as well as regeneration behavior. The results show that γ-Al 2 O 3 had good resistance to acid gases and the arsenic adsorption by γ-Al 2 O 3 could be effectively carried out at a wide temperature range between 573 and 1023 K. Nevertheless, adsorption at higher-temperature (like 1173 K) leaded to the decrease of surface area and the rearrangement of crystal structure of γ-Al 2 O 3 , reducing the active sites for arsenic adsorption. The adsorption of arsenic was confirmed to occur at different active sites in γ-Al 2 O 3 by forming various adsorbed species. Increasing temperature facilitated arsenic transformation into more stable chemisorbed As 3+ and As 5+ which were difficult to remove through thermal treatment regeneration. Fortunately, the regeneration of spent γ-Al 2 O 3 could be well performed using NaOH solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Comparative Assessment of Arsenic Risks and the Nutritional Benefits of Fish Consumption in Kuwait: Arsenic Versus Omega 3-Fatty Acids.

PubMed

Husain, Adnan; Kannan, Kurunthachalam; Chan, Hing Man; Laird, Brian; Al-Amiri, Hanan; Dashti, Basma; Sultan, Anwar; Al-Othman, Amani; Mandekar, Bedraya

2017-01-01

Inorganic and organic forms of arsenic (As), as well as omega-3 fatty acids were measured in 578 fish/seafood samples that belong to 15 species of commonly consumed seafood in Kuwait. Arsenic speciation data, with the toxicological profile of inorganic arsenic (iAs) and fish consumption rates were applied in a probabilistic risk assessment to estimate the risk from exposure to iAs. The nutritional benefits of omega-3-fatty acid levels in various species of fish were taken into consideration. Results showed that the mean daily intake of iAs through fish consumption among the Kuwaiti population was 0.058 µg/kg/day, and the 95th percentile was 0.15 µg/kg/day. Although the mean intake level did not exceed the incremental lifetime cancer risk (ILCR) at 1 × 10 -4 , the 95th percentile of iAs intake showed an ILCR of 2.7 × 10 -4 . Kuwaiti children (aged 6-12 years) were found to have a higher mean intake of iAs at 0.10 µg/kg/day with 68% of children in this category, exceeding the risk specific dose associated with an ILCR of 1 × 10 -4 . The fish species, hammor (grouper; Epinephelus coioides), is the top contributor to iAs intake, and tuna is the major source of omega 3-fatty acids for the Kuwaiti population.

Potential anthropogenic mobilisation of mercury and arsenic from soils on mineralised rocks, Northland, New Zealand.

PubMed

Craw, D

2005-02-01

Eroded roots of hot spring systems in Northland, New Zealand consist of mineralised rocks containing sulfide minerals. Marcasite and cinnabar are the dominant sulfides with subordinate pyrite. Deep weathering and leached soil formation has occurred in a warm temperate to subtropical climate with up to 3 m/year rainfall. Decomposition of the iron sulfides in natural and anthropogenic rock exposures yields acid rock drainage with pH typically between 2 and 4, and locally down to pH 1. Soils and weathered rocks developed on basement greywacke have negligible acid neutralisation capacity. Natural rainforest soils have pH between 4 and 5 on unmineralised greywacke, and pH is as low as 3.5 in soils on mineralised rocks. Roads with aggregate made from mineralised rocks have pH near 3, and quarries from which the rock was extracted can have pH down to 1. Mineralised rocks are enriched in arsenic and mercury, both of which are environmentally available as solid solution impurities in iron sulfides and phosphate minerals. Base metals (Cu, Pb, Zn) are present at low levels in soils, at or below typical basement rock background. Decomposition of the iron sulfides releases the solid solution arsenic and mercury into the acid rock drainage solutions. Phosphate minerals release their impurities only under strongly acid conditions (pH<1). Arsenic and mercury are adsorbed on to iron oxyhydroxides in soils, concentrated in the C horizon, with up to 4000 ppm arsenic and 100 ppm mercury. Waters emanating from acid rock drainage areas have arsenic and mercury below drinking water limits. Leaching experiments and theoretical predictions indicate that both arsenic and mercury are least mobile in acid soils, at pH of c. 3-4. This optimum pH range for fixation of arsenic and mercury on iron oxyhydroxides in soils is similar to natural pH at the field site of this study. However, neutralisation of acid soils developed on mineralised rocks is likely to decrease adsorption and enhance

ARSENIC SEPARATION FROM WATER USING ZEOLITES

EPA Science Inventory

Arsenic is known to be a hazardous contaminant in drinking water. The presence of arsenic in water supplies has been linked to arsenical dermatosis and skin cancer . Zeolites are well known for their ion exchange capacities. In the present work, the potential use of a variety of ...

Effect of plasma homocysteine level and urinary monomethylarsonic acid on the risk of arsenic-associated carotid atherosclerosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, M.-M.; Graduate Institute of Medicine, College of Medicine, Fu-Jen Catholic University, Taipei, Taiwan; Chiou, H.-Y.

2006-10-01

Arsenic-contaminated well water has been shown to increase the risk of atherosclerosis. Because of involving S-adenosylmethionine, homocysteine may modify the risk by interfering with the biomethylation of ingested arsenic. In this study, we assessed the effect of plasma homocysteine level and urinary monomethylarsonic acid (MMA{sup V}) on the risk of atherosclerosis associated with arsenic. In total, 163 patients with carotid atherosclerosis and 163 controls were studied. Lifetime cumulative arsenic exposure from well water for study subjects was measured as index of arsenic exposure. Homocysteine level was determined by high-performance liquid chromatography (HPLC). Proportion of MMA{sup V} (MMA%) was calculated bymore » dividing with total arsenic species in urine, including arsenite, arsenate, MMA{sup V}, and dimethylarsinic acid (DMA{sup V}). Results of multiple linear regression analysis show a positive correlation of plasma homocysteine levels to the cumulative arsenic exposure after controlling for atherosclerosis status and nutritional factors (P < 0.05). This correlation, however, did not change substantially the effect of arsenic exposure on the risk of atherosclerosis as analyzed in a subsequent logistic regression model. Logistic regression analyses also show that elevated plasma homocysteine levels did not confer an independent risk for developing atherosclerosis in the study population. However, the risk of having atherosclerosis was increased to 5.4-fold (95% CI, 2.0-15.0) for the study subjects with high MMA% ({>=}16.5%) and high homocysteine levels ({>=}12.7 {mu}mol/l) as compared to those with low MMA% (<9.9%) and low homocysteine levels (<12.7 {mu}mol/l). Elevated homocysteinemia may exacerbate the formation of atherosclerosis related to arsenic exposure in individuals with high levels of MMA% in urine.« less

Arsenic is associated with reduced effect of folic acid in myelomeningocele prevention: a case control study in Bangladesh

USDA-ARS?s Scientific Manuscript database

Background: Arsenic induces neural tube defects in several animal models, but its potential to cause neural tube defects in humans is unknown. Our objective was to investigate the associations between maternal arsenic exposure, periconceptional folic acid supplementation, and risk of posterior neura...

The effect of arsenic contamination on amino acids metabolism in Spinacia oleracea L.

PubMed

Pavlík, Milan; Pavlíková, Daniela; Staszková, Ludmila; Neuberg, Marek; Kaliszová, Regina; Száková, Jirina; Tlustos, Pavel

2010-09-01

Changes of amino acid concentrations (proline, glutamate, asparagine, aspartate, alanine) and glutamate kinase activity (GKA) in plants under arsenic chronic stress reported here reveal their role in plant arsenic stress adaptation. Results of the pot experiment confirmed the toxic effect of arsenic at tested levels (As1=25 mg As kg(-1) soil, As2=50 mg As kg(-1) soil, As3=75 mg As kg(-1) soil) for spinach. Growing available arsenic contents in soil were associated with the strong inhibition of above-ground biomass and with the enhancement of As plant content. The changes of glutamate, asparagine, aspartate and proline levels in the plants showed strong linear dependences on arsenic concentration in plants (R2=0.60-0.90). Compared to the untreated control, concentrations of free proline and aspartate of As3 treatment were enhanced up to 381% and 162%, respectively. The significant changes of glutamate were observed on As2 and As3 treatments (increased level up to 188, i.e. 617%). Arsenic in plants was shown to be an inhibitor of glutamase kinase activity (R2=0.91). Inhibition of GKA resulted in an increase in the content of glutamate that is used in synthesis of phytochelatins in plant cells. Concentration of alanine did not have a confirmed linear dependence on arsenic concentration in plant (R2=0.05). The changes of its concentrations could be affected by changes of pH in plant cell or induction of alanine aminotransferase by hypoxia. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Urinary Arsenic Speciation in Children and Pregnant Women from Spain.

PubMed

Signes-Pastor, Antonio J; Carey, Manus; Vioque, Jesus; Navarrete-Muñoz, Eva M; Rodríguez-Dehli, Cristina; Tardón, Adonina; Begoña-Zubero, Miren; Santa-Marina, Loreto; Vrijheid, Martine; Casas, Maribel; Llop, Sabrina; Gonzalez-Palacios, Sandra; Meharg, Andrew A

2017-01-01

Inorganic arsenic (i-As) is a non-threshold human carcinogen that has been associated with several adverse health outcomes. Exposure to i-As is of particular concern among pregnant women, infants and children, as they are specifically vulnerable to the adverse health effects of i-As, and in utero and early-life exposure, even low to moderate levels of i-As, may have a marked effect throughout the lifespan. Ion chromatography-mass spectrometry detection (IC-ICP-MS) was used to analyse urinary arsenic speciation, as an exposure biomarker, in samples of 4-year-old children with relatively low-level arsenic exposure living in different regions in Spain including Asturias, Gipuzkoa, Sabadell and Valencia. The profile of arsenic metabolites in urine was also determined in samples taken during pregnancy (1st trimester) and in the children from Valencia of 7 years old. The median of the main arsenic species found in the 4-year-old children was 9.71 μg/l (arsenobetaine-AsB), 3.97 μg/l (dimethylarsinic acid-DMA), 0.44 μg/l (monomethylarsonic acid-MMA) and 0.35 μg/l (i-As). Statistically significant differences were found in urinary AsB, MMA and i-As according to the study regions in the 4-year-old, and also in DMA among pregnant women and their children. Spearman's correlation coefficient among urinary arsenic metabolites was calculated, and, in general, a strong methylation capacity to methylate i-As to MMA was observed.

TISSUE DISTRIBUTION OF ARSENIC SPECIES IN MICE CHRONICALLY EXPOSED TO METHYLARSONOUS ACID

EPA Science Inventory

The metabolism of inorganic arsenic (iAs) in humans yields toxic and carcinogenic methyl-As (MAs) and dimethyl-As (DMAs) intermediates. Methylarsonous acid (MAsIII) is the most acutely toxic species of characterized iAs metabolites. Here, we examined the concentrations of As spec...

Clean process to destroy arsenic-containing organic compounds with recovery of arsenic

DOEpatents

Upadhye, R.S.; Wang, F.T.

1996-08-13

A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic. 1 fig.

Clean process to destroy arsenic-containing organic compounds with recovery of arsenic

DOEpatents

Upadhye, Ravindra S.; Wang, Francis T.

1996-01-01

A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic.

Adsorption and removal of arsenic (V) using crystalline manganese (II,III) oxide: Kinetics, equilibrium, effect of pH and ionic strength.

PubMed

Babaeivelni, Kamel; Khodadoust, Amid P; Bogdan, Dorin

2014-01-01

Manganese (II,III) oxide (Mn3O4) crystalline powder was evaluated as a potential sorbent for removal of arsenic (V) from water. Adsorption isotherm experiments were carried out to determine the adsorption capacity using de-ionized (DI) water, a synthetic solution containing bicarbonate alkalinity, and two natual groundwater samples. Adsorption isotherm data followed the Langmuir and Freundlich equations, indicating favorable adsorption of arsenic (V) onto Mn3O4, while results from the Dubinin-Radushkevich equation were suggestive of chemisorption of arsenic (V). When normalized to the sorbent surface area, the maximum adsorption capacity of Mn3O4 for arsenic (V) was 101 μg m(-2), comparable to that of activated alumina. Arsenic (V) adsorption onto Mn3O4 followed pseudo-second-order kinetics. Adsorption of arsenic (V) was greatest at pH 2, while adsorption at pH 7-9 was within 91% of maximum adsorption, whereas adsorption decreased to 32% of maximum adsorption at pH 10. Surface charge analysis confirmed the adsorption of arsenic (V) onto the acidic surface of the Mn3O4 sorbent with a pHPZC of 7.32. The presence of coexisting ions bicarbonate and phosphate resulted in a decrease in arsenic (V) uptake. Comparable adsorption capacities were obtained for the synthetic solution and both groundwater samples. Overall, crystalline Mn3O4 was an effective and viable sorbent for removal of arsenic (V) from natural water, removing greater than 95% of arsenic (V) from a 1 mg L(-1) solution within 60 min of contact time.

Microbial contributions to coupled arsenic and sulfur cycling in the acid-sulfide hot spring Champagne Pool, New Zealand.

PubMed

Hug, Katrin; Maher, William A; Stott, Matthew B; Krikowa, Frank; Foster, Simon; Moreau, John W

2014-01-01

Acid-sulfide hot springs are analogs of early Earth geothermal systems where microbial metal(loid) resistance likely first evolved. Arsenic is a metalloid enriched in the acid-sulfide hot spring Champagne Pool (Waiotapu, New Zealand). Arsenic speciation in Champagne Pool follows reaction paths not yet fully understood with respect to biotic contributions and coupling to biogeochemical sulfur cycling. Here we present quantitative arsenic speciation from Champagne Pool, finding arsenite dominant in the pool, rim and outflow channel (55-75% total arsenic), and dithio- and trithioarsenates ubiquitously present as 18-25% total arsenic. In the outflow channel, dimethylmonothioarsenate comprised ≤9% total arsenic, while on the outflow terrace thioarsenates were present at 55% total arsenic. We also quantified sulfide, thiosulfate, sulfate and elemental sulfur, finding sulfide and sulfate as major species in the pool and outflow terrace, respectively. Elemental sulfur concentration reached a maximum at the terrace. Phylogenetic analysis of 16S rRNA genes from metagenomic sequencing revealed the dominance of Sulfurihydrogenibium at all sites and an increased archaeal population at the rim and outflow channel. Several phylotypes were found closely related to known sulfur- and sulfide-oxidizers, as well as sulfur- and sulfate-reducers. Bioinformatic analysis revealed genes underpinning sulfur redox transformations, consistent with sulfur speciation data, and illustrating a microbial role in sulfur-dependent transformation of arsenite to thioarsenate. Metagenomic analysis also revealed genes encoding for arsenate reductase at all sites, reflecting the ubiquity of thioarsenate and a need for microbial arsenate resistance despite anoxic conditions. Absence of the arsenite oxidase gene, aio, at all sites suggests prioritization of arsenite detoxification over coupling to energy conservation. Finally, detection of methyl arsenic in the outflow channel, in conjunction with

Retinoic Acid and Arsenic Synergize to Eradicate Leukemic Cells in a Mouse Model of Acute Promyelocytic Leukemia

PubMed Central

Lallemand-Breitenbach, Valérie; Guillemin, Marie-Claude; Janin, Anne; Daniel, Marie-Thérèse; Degos, Laurent; Kogan, Scott C.; Michael Bishop, J.; de Thé, Hugues

1999-01-01

In acute promyelocytic leukemia (APL) patients, retinoic acid (RA) triggers differentiation while arsenic trioxide (arsenic) induces both a partial differentiation and apoptosis. Although their mechanisms of action are believed to be distinct, these two drugs both induce the catabolism of the oncogenic promyelocytic leukemia (PML)/RARα fusion protein. While APL cell lines resistant to one agent are sensitive to the other, the benefit of combining RA and arsenic in cell culture is controversial, and thus far, no data are available in patients. Using syngenic grafts of leukemic blasts from PML/RARα transgenic mice as a model for APL, we demonstrate that arsenic induces apoptosis and modest differentiation, and prolongs mouse survival. Furthermore, combining arsenic with RA accelerates tumor regression through enhanced differentiation and apoptosis. Although RA or arsenic alone only prolongs survival two- to threefold, associating the two drugs leads to tumor clearance after a 9-mo relapse-free period. These studies establishing RA/arsenic synergy in vivo prompt the use of combined arsenic/RA treatments in APL patients and exemplify how mouse models of human leukemia can be used to design or optimize therapies. PMID:10190895

A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations

PubMed Central

Hata, Akihisa; Kurosawa, Hidetoshi; Endo, Yoko; Yamanaka, Kenzo; Fujitani, Noboru; Endo, Ginji

2016-01-01

Objectives: The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. Methods: We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Results: iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m3 of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. Conclusion: We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m3 iAs exposure, respectively. PMID:27010090

Application of natural citric acid sources and their role on arsenic removal from drinking water: a green chemistry approach.

PubMed

Majumder, Santanu; Nath, Bibhash; Sarkar, Simita; Islam, Sk Mijanul; Bundschuh, Jochen; Chatterjee, Debashis; Hidalgo, Manuela

2013-11-15

Solar Oxidation and Removal of Arsenic (SORAS) is a low-cost non-hazardous technique for the removal of arsenic (As) from groundwater. In this study, we tested the efficiency of natural citric acid sources extracted from tomato, lemon and lime to promote SORAS for As removal at the household level. The experiment was conducted in the laboratory using both synthetic solutions and natural groundwater samples collected from As-polluted areas in West Bengal. The role of As/Fe molar ratios and citrate doses on As removal efficiency were checked in synthetic samples. The results demonstrate that tomato juice (as citric acid) was more efficient to remove As from both synthetic (percentage of removal: 78-98%) and natural groundwater (90-97%) samples compared to lemon (61-83% and 79-85%, respectively) and lime (39-69% and 63-70%, respectively) juices. The As/Fe molar ratio and the citrate dose showed an 'optimized central tendency' on As removal. Anti-oxidants, e.g. 'hydroxycinnamates', found in tomato, were shown to have a higher capacity to catalyze SORAS photochemical reactions compared to 'flavanones' found in lemon or lime. The application of this method has several advantages, such as eco- and user- friendliness and affordability at the household level compared to other low-cost techniques. Copyright © 2012 Elsevier B.V. All rights reserved.

The source of naturally occurring arsenic in a coastal sand aquifer of eastern Australia.

PubMed

O'Shea, Bethany; Jankowski, Jerzy; Sammut, Jesmond

2007-07-01

The discovery of dissolved arsenic in a coastal aquifer used extensively for human consumption has led to widespread concern for its potential occurrence in other sandy coastal environments in eastern Australia. The development of an aquifer specific geomorphic model (herein) suggests that arsenic is regionally derived from erosion of arsenic-rich stibnite (Sb(2)S(3)) mineralisation present in the hinterland. Fluvial processes have transported the eroded material over time to deposit an aquifer lithology elevated in arsenic. Minor arsenic contribution to groundwater is derived from mineralised bedrock below the unconsolidated aquifer. An association with arsenic and pyrite has been observed in the aquifer in small discrete arsenian pyrite clusters rather than actual acid sulfate soil horizons. This association is likely to influence arsenic distribution in the aquifer, but is not the dominant control on arsenic occurrence. Arsenic association with marine clays is considered a function of their increased adsorptive capacity for arsenic and not solely on the influence of sea level inundation of the aquifer sediments during the Quaternary Period. These findings have implications for, but are not limited to, coastal aquifers. Rather, any aquifer containing sediments derived from mineralised provenances may be at risk of natural arsenic contamination. Groundwater resource surveys should thus incorporate a review of the aquifer source provenance when assessing the likely risk of natural arsenic occurrence in an aquifer.

Containing arsenic-enriched groundwater tracing lead isotopic compositions of common arsenical pesticides in a coastal Maine watershed

USGS Publications Warehouse

Ayuso, Robert A.; Foley, Nora K.; Robinson, Glipin R.; Colvin, A.S.; Lipfert, G.; Reeve, A.S.

2006-01-01

Arsenical pesticides and herbicides were extensively used on apple, blueberry, and potato crops in New England during the first half of the twentieth century. Lead arsenate was the most heavily used arsenical pesticide until it was officially banned. Lead arsenate, calcium arsenate, and sodium arsenate have similar Pb isotope compositions: 208Pb207Pb = 2.3839-2.4722, and 206Pb207Pb = 1.1035-1.2010. Other arsenical pesticides such as copper acetoarsenite (Paris green), methyl arsonic acid and methane arsonic acid, as well as arsanilic acid are widely variable in isotope composition. Although a complete understanding of the effects of historical use of arsenical pesticides is not available, initial studies indicate that arsenic and lead concentrations in stream sediments in New England are higher in agricultural areas that intensely used arsenical pesticides than in other areas. The Pb isotope compositions of pesticides partially overlap values of stream sediments from areas with the most extensive agricultural use. The lingering effects of arsenical pesticide use were tested in a detailed geochemical and isotopic study of soil profiles from a watershed containing arsenic-enriched ground water in coastal Maine. Acid-leach compositions of the soils represent lead adsorbed to mineral surfaces or held in soluble minerals (Fe- and Mn-hydroxides, carbonate, and some micaceous minerals), whereas residue compositions likely reflect bedrock compositions. The soil profiles contain labile Pb (acid-leach) showing a moderate range in 206Pb 207Pb (1.1870-1.2069), and 208Pb207Pb (2.4519-2.4876). Isotope values vary as a function of depth: the lowest Pb isotope ratios (e.g.,208Pb206Pb) representing labile lead are in the uppermost soil horizons. Lead contents decrease with depth in the soil profiles. Arsenic contents show no clear trend with depth. A multi-component mixing scheme that included lead from the local parent rock (Penobscot Formation), lead derived from combustion of

Geochemical processes controlling fate and transport of arsenic in acid mine drainage (AMD) and natural systems.

PubMed

Cheng, Hefa; Hu, Yuanan; Luo, Jian; Xu, Bin; Zhao, Jianfu

2009-06-15

Acid mine drainage (AMD) is often accompanied with elevated concentrations of arsenic, in the forms of arsenite, As(III), and/or arsenate, As(V), due to the high affinity of arsenic for sulfide mineral ores. This review summarizes the major geochemical processes controlling the release, speciation, fate, and distribution of inorganic arsenic in mine drainage and natural systems. Arsenic speciation depends highly on redox potential and pH of the solution, and arsenite can be oxidized to the less toxic arsenate form. Homogeneous oxidation of arsenite occurs rather slowly while its heterogeneous oxidation on mineral surfaces can greatly enhance the reaction rates. Little evidence suggests that precipitation reaction limits the concentrations of arsenic in natural water, while co-precipitation may lead to rapid arsenic removal when large amount of iron hydroxides precipitate out of the aqueous phase upon neutralization of the mine drainage. Both arsenate and arsenite adsorb on common metal oxides and clay minerals through formation of inner-sphere and/or outer-sphere complexes, controlling arsenic concentration in natural water bodies. Arsenite adsorbs less strongly than arsenate in the typical pH range of natural water and is more mobile. Part of the adsorbed arsenic species can be exchanged by common anions (e.g., PO(4)(3-) and SO(4)(2-)), especially phosphate, which leads to their re-mobilization. Understanding the geochemistry of arsenic is helpful for predicting its mobility and fate in AMD and natural systems, and for designing of cost-effective remediation/treatment strategies to reduce the occurrence and risk of arsenic contamination.

Evaluation of urinary speciated arsenic in NHANES: Issues in interpretation in the context of potential inorganic arsenic exposure

EPA Science Inventory

Urinary dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) are among the commonly used biomarkers for inorganic arsenic (iAs) exposure, but may also arise from seafood consumption and organoarsenical pesticide applications. We examined speciated urinary arsenic data from...

Arsenic detection in water: YPO{sub 4}:Eu{sup 3+} nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Debasish; Luwang, Meitram Niraj, E-mail: mn.luwang@ncl.res.in; Academy of Scientific and Innovative Research

This work reports on the novel technique of detection of arsenic in aqueous solution utilising the luminescence properties of lanthanide doped nanomaterials. Eu{sup 3+} (5%) doped YPO{sub 4}nanorodswere utilised for the said experiment. Co-precipitation method was used for the synthesis of the materials and characterised them with different instrumental techniques like X-ray diffraction (XRD), Infra-red (IR), UV-absorption, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence studies. This nanoparticle can adsorb both arsenic and arsenious acids. We studied the effect of arsenic adsorption on the luminescence behaviour of the nanoparticles. Arsenic acid enhanced the luminescencemore » intensity whereas arsenious acid quenched the luminescence. This luminescence enhancement or quenching is related with arsenic concentration. This relation of luminescence property with concentration of arsenic can be used to detect arsenic in industrial waste. - Graphical abstract: Novel technique of detection of Arsenic ion in aqueous solution utilising the luminescence properties of lanthanide doped nanomaterials. Potential application for detection of arsenic in drinking and industrial waste water. - Highlights: • Novel technique of detection of Arsenic in aqueous solution by YPO{sub 4}:Eu{sup 3+} nanomaterials. • The effect of arsenic adsorption on the luminescence behaviour of the nanoparticles was studied. • Arsenic acid enhance whereas arsenious acid quenches the luminescence intensity. • This technique can be used to detect arsenic in industrial waste.« less

Distribution and speciation of arsenic by transplacental and early life exposure to inorganic arsenic in offspring rats.

PubMed

Xi, Shuhua; Jin, Yaping; Lv, Xiuqiang; Sun, Guifan

2010-04-01

The amount of arsenic compounds was determined in the liver and brain of pups and in breast milk in the pup's stomach in relation to the route of exposure: transplacental, breast milk, or drinking water. Forty-eight pregnant rats were randomly divided into four groups, each group was given free access to drinking water that contained 0, 10, 50, and 100 mg/L NaAsO(2) from gestation day 6 (GD 6) until postnatal day 42 (PND 42). Once pups were weaned, they started to drink the same arsenic-containing water as the dams. Contents of inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and trimethylarsenic acid (TMA) in livers and brains of the pups on PND 0, 15, 28, and 42 and breast milk taken from the pup's stomach on PND 0 and 15 were detected using the hydride generation atomic absorption spectroscopy method. Concentrations of iAs, MMA, and DMA in the breast milk, the brain, and the liver of the pups increased with the concentration of arsenic in drinking water on PND 0, 15, 28, and 42. Compared to the liver or brain, breast milk had the lowest arsenic concentrations. There was a significant decrease in the levels of arsenic species on PND 15 compared to PND 0, 28, or 42. It was confirmed that arsenic species can pass through the placental barrier from dams to offspring and across the blood-brain barrier in the pups, and breast milk from dams exposed to arsenic in drinking water contains less arsenic than the liver and brain of pups.

Availability of arsenic in human milk in women and its correlation with arsenic in urine of breastfed children living in arsenic contaminated areas in Bangladesh.

PubMed

Islam, Md Rafiqul; Attia, John; Alauddin, Mohammad; McEvoy, Mark; McElduff, Patrick; Slater, Christine; Islam, Md Monirul; Akhter, Ayesha; d'Este, Catherine; Peel, Roseanne; Akter, Shahnaz; Smith, Wayne; Begg, Stephen; Milton, Abul Hasnat

2014-12-04

Early life exposure to inorganic arsenic may be related to adverse health effects in later life. However, there are few data on postnatal arsenic exposure via human milk. In this study, we aimed to determine arsenic levels in human milk and the correlation between arsenic in human milk and arsenic in mothers and infants urine. Between March 2011 and March 2012, this prospective study identified a total of 120 new mother-baby pairs from Kashiani (subdistrict), Bangladesh. Of these, 30 mothers were randomly selected for human milk samples at 1, 6 and 9 months post-natally; the same mother baby pairs were selected for urine sampling at 1 and 6 months. Twelve urine samples from these 30 mother baby pairs were randomly selected for arsenic speciation. Arsenic concentration in human milk was low and non-normally distributed. The median arsenic concentration in human milk at all three time points remained at 0.5 μg/L. In the mixed model estimates, arsenic concentration in human milk was non-significantly reduced by -0.035 μg/L (95% CI: -0.09 to 0.02) between 1 and 6 months and between 6 and 9 months. With the progression of time, arsenic concentration in infant's urine increased non-significantly by 0.13 μg/L (95% CI: -1.27 to 1.53). Arsenic in human milk at 1 and 6 months was not correlated with arsenic in the infant's urine at the same time points (r = -0.13 at 1 month and r = -0.09 at 6 month). Arsenite (AsIII), arsenate (AsV), monomethyl arsonic acid (MMA), dimethyl arsinic acid (DMA) and arsenobetaine (AsB) were the constituents of total urinary arsenic; DMA was the predominant arsenic metabolite in infant urine. We observed a low arsenic concentration in human milk. The concentration was lower than the World Health Organization's maximum permissible limit (WHO Permissible Limit 15 μg/kg-bw/week). Our findings support the safety of breastfeeding even in arsenic contaminated areas.

Raman spectra of thiolated arsenicals with biological importance.

PubMed

Yang, Mingwei; Sun, Yuzhen; Zhang, Xiaobin; McCord, Bruce; McGoron, Anthony J; Mebel, Alexander; Cai, Yong

2018-03-01

Surface enhanced Raman scattering (SERS) has great potential as an alternative tool for arsenic speciation in biological matrices. SERS measurements have advantages over other techniques due to its ability to maintain the integrity of arsenic species and its minimal requirements for sample preparation. Up to now, very few Raman spectra of arsenic compounds have been reported. This is particularly true for thiolated arsenicals, which have recently been found to be widely present in humans. The lack of data for Raman spectra in arsenic speciation hampers the development of new tools using SERS. Herein, we report the results of a study combining the analysis of experimental Raman spectra with that obtained from density functional calculations for some important arsenic metabolites. The results were obtained with a hybrid functional B3LYP approach using different basis sets to calculate Raman spectra of the selected arsenicals. By comparing experimental and calculated spectra of dimethylarsinic acid (DMA V ), the basis set 6-311++G** was found to provide computational efficiency and precision in vibrational frequency prediction. The Raman frequencies for the rest of organoarsenicals were studied using this basis set, including monomethylarsonous acid (MMA III ), dimethylarsinous acid (DMA III ), dimethylmonothioarinic acid (DMMTA V ), dimethyldithioarsinic acid (DMDTA V ), S-(Dimethylarsenic) cysteine (DMA III (Cys)) and dimethylarsinous glutathione (DMA III GS). The results were compared with fingerprint Raman frequencies from As─O, As─C, and As─S obtained under different chemical environments. These fingerprint vibrational frequencies should prove useful in future measurements of different species of arsenic using SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

The Chemistry and Metabolism of Arsenic

EPA Science Inventory

I. IntrodctionA century of study of the process by which many organisms convert inorganic arsenic into an array of methylated metabolites has answered many questions and has posed some new ones. The capacity of microorganisms to. form volatile arsenic compounds was first recogniz...

A comprehensive review on removal of arsenic using activated carbon prepared from easily available waste materials.

PubMed

Mondal, Monoj Kumar; Garg, Ravi

2017-05-01

Arsenic contamination in water bodies is a serious problem and causes various health problems due to which US Environment Protection Agency (USEPA) set its maximum permissible limit of 10 ppb. The present review article starts with the removal of toxic arsenic using adsorbents prepared from easily available waste materials. Adsorbent either commercial or low-cost adsorbent can be used for arsenic removal but recent research was focused on the low-cost adsorbent. Preparation and activation of various adsorbents were discussed. Adsorption capacities, surface area, thermodynamic, and kinetics data of various adsorbents for As(III) and As(V) removal were compiled. Desorption followed by regeneration and reuse of adsorbents is an important step in adsorption and leads to economical process. Various desorbing and regenerating agents were discussed for arsenic decontamination from the adsorbent surface. Strong acids, bases, and salts are the main desorbing agents. Disposal of arsenic-contaminated adsorbent and arsenic waste was also a big problem because of the toxic and leaching effect of arsenic. So, arsenic waste was disposed of by proper stabilization/solidification (S/S) technique by mixing it in Portland cement, iron, ash, etc. to reduce the leaching effect.

Arsenic levels in immigrant children from countries at risk of consuming arsenic polluted water compared to children from Barcelona.

PubMed

Piñol, S; Sala, A; Guzman, C; Marcos, S; Joya, X; Puig, C; Velasco, M; Velez, D; Vall, O; Garcia-Algar, O

2015-11-01

Arsenic is a highly toxic element that pollutes groundwater, being a major environmental problem worldwide, especially in the Bengal Basin. About 40% of patients in our outpatient clinics come from those countries, and there is no published data about their arsenic exposure. This study compares arsenic exposure between immigrant and native children. A total of 114 children (57 natives, 57 immigrants), aged 2 months to 16 years, were recruited and sociodemographic and environmental exposure data were recorded. Total arsenic in urine, hair, and nails and arsenic-speciated compounds in urine were determined. We did not find significant differences in total and inorganic arsenic levels in urine and hair, but in organic arsenic monomethylarsenic acid (MMA) and dimethylarsinous acid (DMA) in urine and in total arsenic in nails. However, these values were not in the toxic range. There were significant differences between longer than 5 years exposure and less than 5 years exposure (consumption of water from tube wells), with respect to inorganic and organic MMA arsenic in urine and total arsenic in nails. There was partial correlation between the duration of exposure and inorganic arsenic levels in urine. Immigrant children have higher arsenic levels than native children, but they are not toxic. At present, there is no need for specific arsenic screening or follow-up in immigrant children recently arrived in Spain from exposure high-risk countries.

Environmentally relevant concentration of arsenic trioxide and humic acid promoted tumor progression of human cervical cancer cells: In vivo and in vitro studies.

PubMed

Tsai, Min-Ling; Yen, Cheng-Chieh; Lu, Fung-Jou; Ting, Hung-Chih; Chang, Horng-Rong

2016-09-01

In a previous study, treatment at higher concentrations of arsenic trioxide or co-exposure to arsenic trioxide and humic acid was found to be inhibited cell growth of cervical cancer cells (SiHa cells) by reactive oxygen species generation. However, treatment at lower concentrations slightly increased cell viability. Here, we investigate the enhancement of progression effects of environmentally relevant concentration of humic acid and arsenic trioxide in SiHa cell lines in vitro and in vivo by measuring cell proliferation, migration, invasion, and the carcinogenesis-related protein (MMP-2, MMP-9, and VEGF-A) expressions. SiHa cells treated with low concentrations of humic acid and arsenic trioxide alone or in co-exposure significantly increased reactive oxygen species, glutathione levels, cell proliferation, scratch wound-healing activities, migration abilities, and MMP-2 expression as compared to the untreated control. In vivo the tumor volume of either single drug (humic acid or arsenic trioxide) or combined drug-treated group was significantly larger than that of the control for an additional 45 days after tumor cell injection on the back of NOD/SCID mice. Levels of MMP-2, MMP-9, and VEGF-A, also significantly increased compared to the control. Histopathologic effects of all tumor cells appeared round in cell shape with high mitosis, focal hyperkeratosis and epidermal hyperplasia in the skin, and some tumor growth in the muscle were observed. Our results may indicate that exposure to low concentrations of arsenic trioxide and humic acid is associated with the progression of cervical cancer. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1121-1132, 2016. © 2015 Wiley Periodicals, Inc.

Low-level arsenic exposure: nutritional and dietary predictors in first-grade Uruguayan children

PubMed Central

Kordas, Katarzyna; Queirolo, Elena I; Mañay, Nelly; Peregalli, Fabiana; Hsiao, Pao Ying; Lu, Ying; Vahter, Marie

2016-01-01

Arsenic exposure in children is a public health concern but is understudied in relation to the predictors, and effects of low-level exposure. We examined the extent and dietary predictors of exposure to inorganic arsenic in 5–8 year old children from Montevideo, Uruguay. Children were recruited at school; 357 were enrolled, 328 collected morning urine samples, and 317 had two 24-hour dietary recalls. Urinary arsenic metabolites, i.e. inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA), were measured using high-performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS), and the sum concentration (U-As) used for exposure assessment. Proportions of arsenic metabolites (%iAs, %MMA and %DMA) in urine were modelled in OLS regressions as functions of food groups, dietary patterns, nutrient intake, and nutritional status. Exposure to arsenic was low (median U-As: 9.9 µg/L) and household water (water As: median 0.45 µg/L) was not a major contributor to exposure. Children with higher consumption of rice had higher U-As but lower %iAs, %MMA, and higher %DMA. Children with higher meat consumption had lower %iAs and higher %DMA. Higher scores on ”nutrient dense” dietary pattern were related to lower %iAs and %MMA, and higher %DMA. Higher intake of dietary folate was associated with lower %MMA and higher %DMA. Overweight children had lower %MMA and higher %DMA than normal-weight children. In summary, rice was an important predictor of exposure to inorganic arsenic and DMA. Higher meat and folate consumption, diet rich in green leafy and red-orange vegetables and eggs, and higher BMI contributed to higher arsenic methylation capacity. PMID:26828624

Low-level arsenic exposure: Nutritional and dietary predictors in first-grade Uruguayan children.

PubMed

Kordas, Katarzyna; Queirolo, Elena I; Mañay, Nelly; Peregalli, Fabiana; Hsiao, Pao Ying; Lu, Ying; Vahter, Marie

2016-05-01

Arsenic exposure in children is a public health concern but is understudied in relation to the predictors, and effects of low-level exposure. We examined the extent and dietary predictors of exposure to inorganic arsenic in 5-8 year old children from Montevideo, Uruguay. Children were recruited at school; 357 were enrolled, 328 collected morning urine samples, and 317 had two 24-h dietary recalls. Urinary arsenic metabolites, i.e. inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA), were measured using high-performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS), and the sum concentration (U-As) used for exposure assessment. Proportions of arsenic metabolites (%iAs, %MMA and %DMA) in urine were modelled in OLS regressions as functions of food groups, dietary patterns, nutrient intake, and nutritional status. Exposure to arsenic was low (median U-As: 9.9µg/L) and household water (water As: median 0.45µg/L) was not a major contributor to exposure. Children with higher consumption of rice had higher U-As but lower %iAs, %MMA, and higher %DMA. Children with higher meat consumption had lower %iAs and higher %DMA. Higher scores on "nutrient dense" dietary pattern were related to lower %iAs and %MMA, and higher %DMA. Higher intake of dietary folate was associated with lower %MMA and higher %DMA. Overweight children had lower %MMA and higher %DMA than normal-weight children. In summary, rice was an important predictor of exposure to inorganic arsenic and DMA. Higher meat and folate consumption, diet rich in green leafy and red-orange vegetables and eggs, and higher BMI contributed to higher arsenic methylation capacity. Copyright © 2016 Elsevier Inc. All rights reserved.

Environmental arsenic exposure and serum matrix metalloproteinase-9.

PubMed

Burgess, Jefferey L; Kurzius-Spencer, Margaret; O'Rourke, Mary Kay; Littau, Sally R; Roberge, Jason; Meza-Montenegro, Maria Mercedes; Gutiérrez-Millán, Luis Enrique; Harris, Robin B

2013-03-01

The objective of this study was to evaluate the relationship between environmental arsenic exposure and serum matrix metalloproteinase (MMP)-9, a biomarker associated with cardiovascular disease and cancer. In a cross-sectional study of residents of Arizona, USA (n=215) and Sonora, Mexico (n=163), drinking water was assayed for total arsenic, and daily drinking water arsenic intake was estimated. Urine was speciated for arsenic, and concentrations were adjusted for specific gravity. Serum was analyzed for MMP-9 using ELISA. Mixed model linear regression was used to assess the relation among drinking water arsenic concentration, drinking water arsenic intake, urinary arsenic sum of species (the sum of arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid), and MMP-9, controlling for autocorrelation within households. Drinking water arsenic concentration and intake were positively associated with MMP-9, both in crude analysis and after adjustment for gender, country/ethnicity, age, body mass index, current smoking, and diabetes. Urinary arsenic sum of species was positively associated with MMP-9 in multivariable analysis only. Using Akaike's Information Criterion, arsenic concentration in drinking water provided a better fitting model of MMP-9 than either urinary arsenic or drinking water arsenic intake. In conclusion, arsenic exposure evaluated using all three exposure metrics was positively associated with MMP-9.

Environmental arsenic exposure and serum matrix metalloproteinase-9

PubMed Central

Burgess, Jefferey L.; Kurzius-Spencer, Margaret; O’Rourke, Mary Kay; Littau, Sally R.; Roberge, Jason; Meza-Montenegro, Maria Mercedes; Gutiérrez-Millán, Luis Enrique; Harris, Robin B.

2014-01-01

The objective of this study was to evaluate the relationship between environmental arsenic exposure and serum matrix metalloproteinase (MMP)-9, a biomarker associated with cardiovascular disease and cancer. In a cross-sectional study of residents of Arizona, USA (n=215) and Sonora, Mexico (n=163), drinking water was assayed for total arsenic, and daily drinking water arsenic intake estimated. Urine was speciated for arsenic and concentrations were adjusted for specific gravity. Serum was analyzed for MMP-9 using ELISA. Mixed model linear regression was used to assess the relation among drinking water arsenic concentration, drinking water arsenic intake, urinary arsenic sum of species (the sum of arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid), and MMP-9, controlling for autocorrelation within households. Drinking water arsenic concentration and intake were positively associated with MMP-9, both in crude analysis and after adjustment for gender, country/ethnicity, age, body mass index, current smoking and diabetes. Urinary arsenic sum of species was positively associated with MMP-9 in multivariable analysis only. Using Akaike’s Information Criterion, arsenic concentration in drinking water provided a better fitting model of MMP-9, than either urinary arsenic or drinking water arsenic intake. In conclusion, arsenic exposure was positively associated with MMP-9 using all three exposure metrics evaluated. PMID:23232971

Renal, hepatic, pulmonary and adrenal tumors induced by prenatal inorganic arsenic followed by dimethylarsinic acid in adulthood in CD1 mice

PubMed Central

Tokar, Erik J.; Diwan, Bhalchandra A.; Waalkes, Michael P.

2012-01-01

Inorganic arsenic, an early life carcinogen in humans and mice, can initiate lesions promotable by other agents in later life. The biomethylation product of arsenic, dimethylarsinic acid (DMA), is a multi-site tumor promoter. Thus, pregnant CD1 mice were given drinking water (0 or 85 ppm arsenic) from gestation day 8 to 18 and after weaning male offspring received DMA (0 or 200 ppm; drinking water) for up to 2 years. No renal tumors occurred in controls or DMA alone treated mice while gestational arsenic exposure plus later DMA induced a significant renal tumor incidence of 17% (primarily renal cell carcinoma). Arsenic plus DMA or arsenic alone also increased renal hyperplasia over control but DMA alone did not. Arsenic alone, DMA alone and arsenic plus DMA all induced urinary bladder hyperplasia (33–35%) versus control (2%). Compared to control (6%), arsenic alone tripled hepatocellular carcinoma (20%), and arsenic plus DMA doubled this rate again (43%), but DMA alone had no effect. DMA alone, arsenic alone, and arsenic plus DMA increased lung adenocarcinomas and adrenal adenomas versus control. Overall, DMA in adulthood promoted tumors/lesions initiated by prenatal arsenic in the kidney and liver, but acted independently in the urinary bladder, lung and adrenal. PMID:22230260

TISSUE DISTRIBUTION OF ARSENIC SPECIES IN MICE CHRONICALLY EXPOSED TO ARSENITE OR METHYLARSONOUS ACID

EPA Science Inventory

e metabolism of inorganic arsenic (iAs) in humans yields toxic and carcinogenic methyl-As (MAs) and dimethyl-As (DMAs) intermediates. Methylarsonous acid (MAsIII) is the most acutely toxic species among known iAs metabolites. In this study, we examined the concentrations of As sp...

Oral arsenic plus retinoic acid versus intravenous arsenic plus retinoic acid for non-high-risk acute promyelocytic leukaemia: a non-inferiority, randomised phase 3 trial.

PubMed

Zhu, Hong-Hu; Wu, De-Pei; Du, Xin; Zhang, Xi; Liu, Lin; Ma, Jun; Shao, Zong-Hong; Ren, Han-Yun; Hu, Jian-Da; Xu, Kai-Lin; Wang, Jing-Wen; Song, Yong-Ping; Fang, Mei-Yun; Li, Juan; Yan, Xiao-Yan; Huang, Xiao-Jun

2018-06-05

Intravenous arsenic trioxide plus all-trans retinoic acid (ATRA) without chemotherapy is the standard of care for non-high-risk acute promyelocytic leukaemia (white blood cell count ≤10 × 10 9 per L), resulting in cure in more than 95% of cases. However, a pilot study of treatment with oral arsenic realgar-Indigo naturalis formula (RIF) plus ATRA without chemotherapy, which has a more convenient route of administration than the standard intravenous regimen, showed high efficacy. In this study, we compare an oral RIF plus ATRA treatment regimen with the standard intravenous arsenic trioxide plus ATRA treatment regimen in patients with non-high-risk acute promyelocytic leukaemia. We did a multicentre, non-inferiority, open-label, randomised, controlled phase 3 trial at 14 centres in China. Patients aged 18-70 years with newly diagnosed (within 7 days) non-high-risk acute promyelocytic leukaemia, and a WHO performance status of 2 or less were eligible. Patients were randomly assigned (2:1) to receive treatment with RIF-ATRA or arsenic trioxide-ATRA as the induction and consolidation therapy. Randomisation was done centrally with permuted blocks and stratification according to trial centre and was implemented through an interactive web response system. RIF (60 mg/kg bodyweight daily in an oral divided dose) or arsenic trioxide (0·15 mg/kg daily in an intravenous dose) and ATRA (25 mg/m 2 daily in an oral divided dose) were used until complete remission was achieved. The home-based consolidation therapy was RIF (60 mg/kg daily in an oral divided dose) or intravenous arsenic trioxide (0·15 mg/kg daily in an intravenous dose) in a 4-week on 4-week off regimen for four cycles and ATRA (25 mg/m 2 daily in an oral divided dose) in a 2-week on 2-week off regimen for seven cycles. Patients and treating physicians were not masked to treatment allocation. The primary outcome was event-free survival at 2 years. A non-inferiority margin of -10% was used to assess non

Combined effects of low-molecular-weight organic acids on mobilization of arsenic and lead from multi-contaminated soils.

PubMed

Onireti, Olaronke O; Lin, Chuxia; Qin, Junhao

2017-03-01

A batch experiment was conducted to examine the combined effects of three common low-molecular-weight organic acids (LMWOAs) on the mobilization of arsenic and lead in different types of multi-contaminated soils. The capacity of individual LMWOAs (at a same molar concentration) to mobilize soil-borne As and Pb varied significantly. The combination of the organic acids did not make a marked "additive" effect on the mobilization of the investigated three elements. An "antagonistic" effect on element mobilization was clear in the treatments involving oxalic acid for some soils. The acid strength of a LMWOA did not play an important role in controlling the mobilization of elements. While the mobilization of As and Pb was closely associated with the dissolution of soil-borne Fe, soil properties such as original soil pH, organic matter contents and the total amount of the element relative to the total Fe markedly complicated the mobility of that element. Aging led to continual consumption of proton introduced from addition of LMWOAs and consequently caused dramatic changes in solution-borne Fe, which in turn resulted in change in As and Pb in the soil solution though different elements behaved differently. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arsenic metabolism efficiency has a causal role in arsenic toxicity: Mendelian randomization and gene-environment interaction.

PubMed

Pierce, Brandon L; Tong, Lin; Argos, Maria; Gao, Jianjun; Farzana, Jasmine; Roy, Shantanu; Paul-Brutus, Rachelle; Rahaman, Ronald; Rakibuz-Zaman, Muhammad; Parvez, Faruque; Ahmed, Alauddin; Quasem, Iftekhar; Hore, Samar K; Alam, Shafiul; Islam, Tariqul; Harjes, Judith; Sarwar, Golam; Slavkovich, Vesna; Gamble, Mary V; Chen, Yu; Yunus, Mohammad; Rahman, Mahfuzar; Baron, John A; Graziano, Joseph H; Ahsan, Habibul

2013-12-01

Arsenic exposure through drinking water is a serious global health issue. Observational studies suggest that individuals who metabolize arsenic efficiently are at lower risk for toxicities such as arsenical skin lesions. Using two single nucleotide polymorphisms(SNPs) in the 10q24.32 region (near AS3MT) that show independent associations with metabolism efficiency, Mendelian randomization can be used to assess whether the association between metabolism efficiency and skin lesions is likely to be causal. Using data on 2060 arsenic-exposed Bangladeshi individuals, we estimated associations for two 10q24.32 SNPs with relative concentrations of three urinary arsenic species (representing metabolism efficiency): inorganic arsenic (iAs), monomethylarsonic acid(MMA) and dimethylarsinic acid (DMA). SNP-based predictions of iAs%, MMA% and DMA% were tested for association with skin lesion status among 2483 cases and 2857 controls. Causal odds ratios for skin lesions were 0.90 (95% confidence interval[CI]: 0.87, 0.95), 1.19 (CI: 1.10, 1.28) and 1.23 (CI: 1.12, 1.36)for a one standard deviation increase in DMA%, MMA% and iAs%,respectively. We demonstrated genotype-arsenic interaction, with metabolism-related variants showing stronger associations with skin lesion risk among individuals with high arsenic exposure (synergy index: 1.37; CI: 1.11, 1.62). We provide strong evidence for a causal relationship between arsenic metabolism efficiency and skin lesion risk. Mendelian randomization can be used to assess the causal role of arsenic exposure and metabolism in a wide array of health conditions.exposure and metabolism in a wide array of health conditions.Developing interventions that increase arsenic metabolism efficiency are likely to reduce the impact of arsenic exposure on health.

Urinary arsenic speciation profile in ethnic group of the Atacama desert (Chile) exposed to variable arsenic levels in drinking water.

PubMed

Yáñez, Jorge; Mansilla, Héctor D; Santander, I Paola; Fierro, Vladimir; Cornejo, Lorena; Barnes, Ramón M; Amarasiriwardena, Dulasiri

2015-01-01

Ethnic groups from the Atacama Desert (known as Atacameños) have been exposed to natural arsenic pollution for over 5000 years. This work presents an integral study that characterizes arsenic species in water used for human consumption. It also describes the metabolism and arsenic elimination through urine in a chronically exposed population in northern Chile. In this region, water contained total arsenic concentrations up to 1250 μg L(-1), which was almost exclusively As(V). It is also important that this water was ingested directly from natural water sources without any treatment. The ingested arsenic was extensively methylated. In urine 93% of the arsenic was found as methylated arsenic species, such as monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)]. The original ingested inorganic species [As(V)], represent less than 1% of the total urinary arsenic. Methylation activity among individuals can be assessed by measuring primary [inorganic As/methylated As] and secondary methylation [MMA/DMA] indexes. Both methylation indexes were 0.06, indicating a high biological converting capability of As(V) into MMA and then MMA into DMA, compared with the control population and other arsenic exposed populations previously reported.

Arsenic speciation and sorption in natural environments

USGS Publications Warehouse

Campbell, Kate M.; Nordstrom, D. Kirk

2014-01-01

Aqueous arsenic speciation, or the chemical forms in which arsenic exists in water, is a challenging, interesting, and complicated aspect of environmental arsenic geochemistry. Arsenic has the ability to form a wide range of chemical bonds with carbon, oxygen, hydrogen, and sulfur, resulting in a large variety of compounds that exhibit a host of chemical and biochemical properties. Besides the intriguing chemical diversity, arsenic also has the rare capacity to capture our imaginations in a way that few elements can duplicate: it invokes images of foul play that range from sinister to comedic (e.g., “inheritance powder” and arsenic-spiked elderberry wine). However, the emergence of serious large-scale human health problems from chronic arsenic exposure in drinking water has placed a high priority on understanding environmental arsenic mobility, toxicity, and bioavailability, and chemical speciation is key to these important questions. Ultimately, the purpose of arsenic speciation research is to predict future occurrences, mitigate contamination, and provide successful management of water resources.

Arsenic induces structural and compositional colonic microbiome change and promotes host nitrogen and amino acid metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dheer, Rishu; Patterson, Jena; Dudash, Mark

changes in microbial community structure, composition and nitrite reductase expression. • The profile of nitrogen and nitroamino acid change caused by arsenic may relect increased risk of cardiovascular pathogenesis.« less

Removal of arsenic and cadmium with sequential soil washing techniques using Na2EDTA, oxalic and phosphoric acid: Optimization conditions, removal effectiveness and ecological risks.

PubMed

Wei, Meng; Chen, Jiajun; Wang, Xingwei

2016-08-01

Testing of sequential soil washing in triplicate using typical chelating agent (Na2EDTA), organic acid (oxalic acid) and inorganic weak acid (phosphoric acid) was conducted to remediate soil contaminated by heavy metals close to a mining area. The aim of the testing was to improve removal efficiency and reduce mobility of heavy metals. The sequential extraction procedure and further speciation analysis of heavy metals demonstrated that the primary components of arsenic and cadmium in the soil were residual As (O-As) and exchangeable fraction, which accounted for 60% and 70% of total arsenic and cadmium, respectively. It was determined that soil washing agents and their washing order were critical to removal efficiencies of metal fractions, metal bioavailability and potential mobility due to different levels of dissolution of residual fractions and inter-transformation of metal fractions. The optimal soil washing option for arsenic and cadmium was identified as phosphoric-oxalic acid-Na2EDTA sequence (POE) based on the high removal efficiency (41.9% for arsenic and 89.6% for cadmium) and the minimal harmful effects of the mobility and bioavailability of the remaining heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Urinary Arsenic Metabolites in Children and Adults Exposed to Arsenic in Drinking Water in Inner Mongolia, China

PubMed Central

Sun, Guifan; Xu, Yuanyuan; Li, Xin; Jin, Yaping; Li, Bing; Sun, Xiance

2007-01-01

Background We report the concentrations and distributions of urinary arsenic (As) metabolites in 233 residents exposed to 20, 90, or 160 μg/L inorganic arsenic (iAs) in drinking water from three villages in Hohhot, Inner Mongolia, China, that formed one control and two exposed groups. Methods We used hydride generation-atomic absorption spectrometry (HGAAS) to determine iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Results The concentrations of each urinary As species in the two exposed groups were significantly higher than in the control group for both children and adults. Both children and adults in exposed groups had higher percent iAs and MMA and lower percent DMA, and low primary and secondary methylation indices (PMI and SMI, respectively) than those in the control group. However, children showed significant increases in percent DMA and the SMI as well as decreases in the percent MMA when the iAs exposure level increased from 90 to 160 μg/L. In addition, children in the two exposed groups showed lower percent MMA but higher percent DMA and higher SMI than adults in the same exposed group. No significant differences in As metabolite concentrations and distributions were found between males and females in each group. A significant correlation was also found in the SMI between 11 pairs of children and their mothers from the 160-μg/L–exposed group. Conclusions Children had higher a capacity for secondary methylation of As than adults when exposed to the same concentrations of iAs in drinking water. Exposure to As may increase the capacity for methylation in children to some extent. PMID:17450238

Oxidation and detoxification of trivalent arsenic species.

PubMed

Aposhian, H Vasken; Zakharyan, Robert A; Avram, Mihaela D; Kopplin, Michael J; Wollenberg, Michael L

2003-11-15

Arsenic compounds with a +3 oxidation state are more toxic than analogous compounds with a +5 oxidation state, for example, arsenite versus arsenate, monomethylarsonous acid (MMA(III)) versus monomethylarsonic acid (MMA(V)), and dimethylarsinous acid (DMA(III)) versus dimethylarsinic acid (DMA(V)). It is no longer believed that the methylation of arsenite is the beginning of a methylation-mediated detoxication pathway. The oxidation of these +3 compounds to their less toxic +5 analogs by hydrogen peroxide needs investigation and consideration as a potential mechanism for detoxification. Xanthine oxidase uses oxygen to oxidize hypoxanthine to xanthine to uric acid. Hydrogen peroxide and reactive oxygen are also products. The oxidation of +3 arsenicals by the hydrogen peroxide produced in the xanthine oxidase reaction was blocked by catalase or allopurinol but not by scavengers of the hydroxy radical, e.g., mannitol or potassium iodide. Melatonin, the singlet oxygen radical scavenger, did not inhibit the oxidation. The production of H2O2 by xanthine oxidase may be an important route for decreasing the toxicity of trivalent arsenic species by oxidizing them to their less toxic pentavalent analogs. In addition, there are many other reactions that produce hydrogen peroxide in the cell. Although chemists have used hydrogen peroxide for the oxidation of arsenite to arsenate to purify water, we are not aware of any published account of its potential importance in the detoxification of trivalent arsenicals in biological systems. At present, this oxidation of the +3 oxidation state arsenicals is based on evidence from in vitro experiments. In vivo experiments are needed to substantiate the role and importance of H2O2 in arsenic detoxication in mammals.

Intercomparison of analytical methods for arsenic speciation in human urine.

PubMed Central

Crecelius, E; Yager, J

1997-01-01

An intercomparison exercise was conducted for the quantification of arsenic species in spiked human urine. The primary objective of the exercise was to determine the variance among laboratories in the analysis of arsenic species such as inorganic As (As+3 and As+5), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Laboratories that participated had previous experience with arsenic speciation analysis. The results of this interlaboratory comparison are encouraging. There is relatively good agreement on the concentrations of these arsenic species in urine at concentrations that are relevant to research on the metabolism of arsenic in humans and other mammals. Both the accuracy and precision are relatively poor for arsenic concentrations of less than about 5 micrograms/l. PMID:9288500

Intercomparison of analytical methods for arsenic speciation in human urine.

PubMed

Crecelius, E; Yager, J

1997-06-01

An intercomparison exercise was conducted for the quantification of arsenic species in spiked human urine. The primary objective of the exercise was to determine the variance among laboratories in the analysis of arsenic species such as inorganic As (As+3 and As+5), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Laboratories that participated had previous experience with arsenic speciation analysis. The results of this interlaboratory comparison are encouraging. There is relatively good agreement on the concentrations of these arsenic species in urine at concentrations that are relevant to research on the metabolism of arsenic in humans and other mammals. Both the accuracy and precision are relatively poor for arsenic concentrations of less than about 5 micrograms/l.

Amino acid composition and antioxidant capacity of Spanish honeys.

PubMed

Pérez, Rosa Ana; Iglesias, María Teresa; Pueyo, Encarnación; Gonzalez, Montserrat; de Lorenzo, Cristina

2007-01-24

The amino acid composition of 53 honey samples from Spain, consisting of 39 floral, 5 honeydew, and 9 blend honeys, has been determined. Physicochemical characteristics, polyphenolic content, amino acid composition, and estimation of the radical scavenging capacity against the stable free radical DPPH of the honey samples were analyzed. The resulting data have been statistically evaluated. The results showed that pH, acidity, net absorbance, electrical conductivity, and total polyphenolic contents of the honeys showed a strong correlation with the radical scavenging capacity. The correlation between the radical scavenging capacity of honey and amino acid contents was high with 18 of the 20 amino acids detected, with correlation values higher than those obtained for polyphenolic content. These results suggest that the amino acid composition of honey is an indicator of the sample's scavenging capacity.

Airborne arsenic and urinary excretion of arsenic metabolites during boiler cleaning operations in a Slovak coal-fired power plant.

PubMed Central

Yager, J W; Hicks, J B; Fabianova, E

1997-01-01

Little information is available on the relationship between occupational exposure to inorganic arsenic in coal fly ash and urinary excretion of arsenic metabolites. This study ws undertaken in a coal-fired power plant in Slovakia during a routine maintenance outage. Arsenic was measured in the breathing zone of workers during 5 consecutive workdays, and urine samples were obtained for analysis of arsenic metabolites--inorganic arsenic (Asi), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)--prior to the start of each shift. Results from a small number of cascade impactor air samples indicated that approximately 90% of total particle mass and arsenic was present in particle size fractions >/= 3.5 micron. The 8-hr time-weighted average (TWA) mean arsenic air concentration was 48.3 microg/m3 (range 0.17-375.2) and the mean sum of urinary arsenic (SigmaAs) metabolites was 16.9 microg As/g creatinine (range 2.6-50.8). For an 8-hr TWA of 10 microg/m3 arsenic from coal fly ash, the predicted mean concentration of the SigmaAs urinary metabolites was 13.2 microg As/G creatinine [95% confidence interval (CI), 10.1-16.3). Comparisons with previously published studies of exposure to arsenic trioxide vapors and dusts in copper smelters suggest that bioavailability of arsenic from airborne coal fly ash (as indicated by urinary excretion) is about one-third that seen in smelters and similar settings. Arsenic compound characteristics, matrix composition, and particle size distribution probably play major roles in determining actual uptake of airborne arsenic. Images Figure 1. A Figure 1. B Figure 2. PMID:9347899

Impaired arsenic metabolism in children during weaning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faengstroem, Britta; Hamadani, Jena; Nermell, Barbro

2009-09-01

Background: Methylation of inorganic arsenic (iAs) via one-carbon metabolism is a susceptibility factor for a range of arsenic-related health effects, but there is no data on the importance of arsenic metabolism for effects on child development. Aim: To elucidate the development of arsenic metabolism in early childhood. Methods: We measured iAs, methylarsonic acid (MA) and dimethylarsinic acid (DMA), the metabolites of iAs, in spot urine samples of 2400 children at 18 months of age. The children were born to women participating in a population-based longitudinal study of arsenic effects on pregnancy outcomes and child development, carried out in Matlab, amore » rural area in Bangladesh with a wide range of arsenic concentrations in drinking water. Arsenic metabolism was evaluated in relation to age, sex, anthropometry, socio-economic status and arsenic exposure. Results: Arsenic concentrations in child urine (median 34 {mu}g/L, range 2.4-940 {mu}g/L), adjusted to average specific gravity of 1.009 g/mL, were considerably higher than that measured at 3 months of age, but lower than that in maternal urine. Child urine contained on average 12% iAs, 9.4% MA and 78% DMA, which implies a marked change in metabolite pattern since infancy. In particular, there was a marked increase in urinary %MA, which has been associated with increased risk of health effects. Conclusion: The arsenic metabolite pattern in urine of children at 18 months of age in rural Bangladesh indicates a marked decrease in arsenic methylation efficiency during weaning.« less

Adsorption behavior and mechanism of different arsenic species on mesoporous MnFe2O4 magnetic nanoparticles.

PubMed

Hu, Qingsong; Liu, Yuling; Gu, Xueyuan; Zhao, Yaping

2017-08-01

Arsenic pollution poses severe threat to human health, therefore dealing with the problem of arsenic contamination in water bodies is extremely important. The adsorption behaviors of different arsenic species, such as arsenate (As(V)), p-arsanilic acid (p-ASA), roxarsone (ROX), dimethylarsenate (DMA) from water using mesoporous bimetal oxide magnetic manganese ferrite nanoparticles (MnFe 2 O 4 ) have been detailedly investigated. The adsorbent was synthesized via a facile co-precipitation approach and recovered conveniently owing to its strong magnetic properties. The obtained MnFe 2 O 4 with large surface area and abundant hydroxyly functional groups exhibited excellent adsorption performance for As(V) and p-ASA, in contrast to ROX and DMA with the maximum adsorption capacities of As(V), p-ASA, ROX and DMA of 68.25 mg g -1 , 59.45 mg g -1 , 51.49 mg g -1 , and 35.77 mg g -1 , respectively. The Langmuir model and the pseudo-second-order kinetic model correlated satisfactorily with the adsorption thermodynamics and kinetics, and thermodynamic parameters depicted the spontaneous endothermic nature for the adsorption of different arsenic species. The adsorption mechanism of different arsenic species onto MnFe 2 O 4 nanoparticles at various pH values could be explained by surface complexation and molecular structural variations. Attenuated Total internal Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) further proved that arsenic species were bonded to the surface of MnFe 2 O 4 through the formation of an inner-sphere complex between the arsenic acid moiety and surface metal centers. The results would help to know the interaction of arsenic species with iron-manganese minerals and the mobility of arsenic species in natural environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Unusual arsenic metabolism in Giant Pandas.

PubMed

Braeuer, Simone; Dungl, Eveline; Hoffmann, Wiebke; Li, Desheng; Wang, Chengdong; Zhang, Hemin; Goessler, Walter

2017-12-01

The total arsenic concentration and the arsenic speciation in urine and feces samples of the two Giant Pandas living at Vienna zoo and of their feed, bamboo, were determined with ICPMS and HPLC-ICPMS. Urine was the main excretion route and accounted for around 90% of the ingested arsenic. The urinary arsenic concentrations were very high, namely up to 179 μg/L. Dimethylarsinic acid (DMA) was the dominating arsenic compound in the urine samples and ranged from 73 to 92% of the total arsenic, which is unusually high for a terrestrial mammal. The feces samples contained around 70% inorganic arsenic and 30% DMA. The arsenic concentrations in the bamboo samples were between 16 and 920 μg/kg dry mass. The main arsenic species in the bamboo extracts was inorganic arsenic. This indicates that the Giant Panda possesses a unique way of very efficiently methylating and excreting the provided inorganic arsenic. This could be essential for the survival of the animal in its natural habitat, because parts of this area are contaminated with arsenic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mouse arsenic (+3 oxidation state) methyltransferase genotype affects metabolism and tissue dosimetry of arsenicals after arsenite administration in drinking water.

PubMed

Chen, Baowei; Arnold, Lora L; Cohen, Samuel M; Thomas, David J; Le, X Chris

2011-12-01

Arsenic (+3 oxidation state) methyltransferase (As3mt) catalyzes methylation of inorganic arsenic (iAs) producing a number of methylated arsenic metabolites. Although methylation has been commonly considered a pathway for detoxification of arsenic, some highly reactive methylated arsenicals may contribute to toxicity associated with exposure to inorganic arsenic. Here, adult female wild-type (WT) C57BL/6 mice and female As3mt knockout (KO) mice received drinking water that contained 1, 10, or 25 ppm (mg/l) of arsenite for 33 days and blood, liver, kidney, and lung were taken for arsenic speciation. Genotype markedly affected concentrations of arsenicals in tissues. Summed concentrations of arsenicals in plasma were higher in WT than in KO mice; in red blood cells, summed concentrations of arsenicals were higher in KO than in WT mice. In liver, kidney, and lung, summed concentrations of arsenicals were greater in KO than in WT mice. Although capacity for arsenic methylation is much reduced in KO mice, some mono-, di-, and tri-methylated arsenicals were found in tissues of KO mice, likely reflecting the activity of other tissue methyltransferases or preabsorptive metabolism by the microbiota of the gastrointestinal tract. These results show that the genotype for arsenic methylation determines the phenotypes of arsenic retention and distribution and affects the dose- and organ-dependent toxicity associated with exposure to inorganic arsenic.

POTENTIAL INDICATORS FOR THE ASSESSMENT OF ARSENIC NATURAL ATTENUATION IN THE SUBSURFACE

EPA Science Inventory

Arsenic is a priority pollutant found in soil and ground water contaminated by arsenic pesticides and industrial wastes. Assessing the natural attenuation capacity of the subsurface for arsenic is a key step leading to successful site remediation. Chemical reactions between arsen...

Arsenic uptake by Lemna minor in hydroponic system.

PubMed

Goswami, Chandrima; Majumder, Arunabha; Misra, Amal Kanti; Bandyopadhyay, Kaushik

2014-01-01

Arsenic is hazardous and causes several ill effects on human beings. Phytoremediation is the use of aquatic plants for the removal of toxic pollutants from external media. In the present research work, the removal efficiency as well as the arsenic uptake capacity of duckweed Lemna minor has been studied. Arsenic concentration in water samples and plant biomass were determined by AAS. The relative growth factor of Lemna minor was determined. The duckweed had potential to remove as well as uptake arsenic from the aqueous medium. Maximum removal of more than 70% arsenic was achieved atinitial concentration of 0.5 mg/1 arsenic on 15th day of experimental period of 22 days. Removal percentage was found to decrease with the increase in initial concentration. From BCF value, Lemna minor was found to be a hyperaccumulator of arsenic at initial concentration of 0.5 mg/L, such that accumulation decreased with increase in initial arsenic concentration.

Arsenic speciation analysis of urine samples from individuals living in an arsenic-contaminated area in Bangladesh.

PubMed

Hata, Akihisa; Yamanaka, Kenzo; Habib, Mohamed Ahsan; Endo, Yoko; Fujitani, Noboru; Endo, Ginji

2012-05-01

Chronic inorganic arsenic (iAs) exposure currently affects tens of millions of people worldwide. To accurately determine the proportion of urinary arsenic metabolites in residents continuously exposed to iAs, we performed arsenic speciation analysis of the urine of these individuals and determined whether a correlation exists between the concentration of iAs in drinking water and the urinary arsenic species content. The subjects were 165 married couples who had lived in the Pabna District in Bangladesh for more than 5 years. Arsenic species were measured using high-performance liquid chromatography and inductively coupled plasma mass spectrometry. The median iAs concentration in drinking water was 55 μgAs/L (range <0.5-332 μgAs/L). Speciation analysis revealed the presence of arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid in urine samples with medians (range) of 16.8 (7.7-32.3), 1.8 (<0.5-3.3), 13.7 (5.6-25.0), and 88.6 μgAs/L (47.9-153.4 μgAs/L), respectively. No arsenobetaine or arsenocholine was detected. The concentrations of the 4 urinary arsenic species were significantly and linearly related to each other. The urinary concentrations of total arsenic and each species were significantly correlated with the iAs concentration of drinking water. All urinary arsenic species are well correlated with each other and with iAs in drinking water. The most significant linear relationship existed between the iAs concentration in drinking water and urinary iAs + MMA concentration. From these results, combined with the effects of seafood ingestion, the best biomarker of iAs exposure is urinary iAs + MMA concentration.

Nonsynonymous Polymorphisms in the Human AS3MT Arsenic Methylation Gene: Implications for Arsenic Toxicity

PubMed Central

2017-01-01

Arsenic methylation, the primary biotransformation in the human body, is catalyzed by the enzyme As(III) S-adenosylmethionine (SAM) methyltransferases (hAS3MT). This process is thought to be protective from acute high-level arsenic exposure. However, with long-term low-level exposure, hAS3MT produces intracellular methylarsenite (MAs(III)) and dimethylarsenite (DMAs(III)), which are considerably more toxic than inorganic As(III) and may contribute to arsenic-related diseases. Several single nucleotide polymorphisms (SNPs) in putative regulatory elements of the hAS3MT gene have been shown to be protective. In contrast, three previously identified exonic SNPs (R173W, M287T, and T306I) may be deleterious. The goal of this study was to examine the effect of single amino acid substitutions in hAS3MT on the activity of the enzyme that might explain their contributions to adverse health effects of environmental arsenic. We identified five additional intragenic variants in hAS3MT (H51R, C61W, I136T, W203C, and R251H). We purified the eight polymorphic hAS3MT proteins and characterized their enzymatic properties. Each enzyme had low methylation activity through decreased affinity for substrate, lower overall rates of catalysis, or lower stability. We propose that amino acid substitutions in hAS3MT with decreased catalytic activity lead to detrimental responses to environmental arsenic and may increase the risk of arsenic-related diseases. PMID:28537708

Vascular smooth muscle dysfunction induced by monomethylarsonous acid (MMA III): a contributing factor to arsenic-associated cardiovascular diseases.

PubMed

Bae, Ok-Nam; Lim, Eun-Kyung; Lim, Kyung-Min; Noh, Ji-Yoon; Chung, Seung-Min; Lee, Moo-Yeol; Yun, Yeo-Pyo; Kwon, Seong-Chun; Lee, Jun-Ho; Nah, Seung-Yeol; Chung, Jin-Ho

2008-11-01

While arsenic in drinking water is known to cause various cardiovascular diseases in human, exact mechanism still remains elusive. Recently, trivalent-methylated arsenicals, the metabolites of inorganic arsenic, were shown to have higher cytotoxic potential than inorganic arsenic. To study the role of these metabolites in arsenic-induced cardiovascular diseases, we investigated the effect of monomethylarsonous acid (MMA III), a major trivalent-methylated arsenical, on vasomotor tone of blood vessels. In isolated rat thoracic aorta and small mesenteric arteries, MMA III irreversibly suppressed normal vasoconstriction induced by three distinct agonists of phenylephrine (PE), serotonin and endothelin-1. Inhibition of vasoconstriction was retained in aortic rings without endothelium, suggesting that MMA III directly impaired the contractile function of vascular smooth muscle. The effect of MMA III was mediated by inhibition of PE-induced Ca2+ increase as found in confocal microscopy and fluorimeter in-lined organ chamber technique. The attenuation of Ca2+ increase was from concomitant inhibition of release from intracellular store and extracellular Ca2+ influx via L-type Ca2+ channel, which was blocked by MMA III as shown in voltage-clamp assay in Xenopus oocytes. MMA III did not affect downstream process of Ca2+, as shown in permeabilized arterial strips. In in vivo rat model, MMA III attenuated PE-induced blood pressure increase indeed, supporting the clinical relevance of these in vitro findings. In conclusion, MMA III-induced smooth muscle dysfunction through disturbance of Ca2+ regulation, which results in impaired vasoconstriction and aberrant blood pressure change. This study will provide a new insight into the role of trivalent-methylated arsenicals in arsenic-associated cardiovascular diseases.

METHYLATED TRIVALENT ARSENICALS AS CANDIDATE ULTIMATE GENOTOXIC FORMS OF ARSENIC: INDUCTION OF CHROMOSOMAL MUTATIONS BUT NOT GENE MUTATIONS

EPA Science Inventory

ABSTRACT
Arsenic is a prevalent human carcinogen whose mutagenicity has not been characterized fully. Exposure to either form of inorganic arsenic, AsIII or AsV, can result in the formation of at least four organic metabolites: monomethylarsonic acid, monomethylarsonous aci...

Preloading hydrous ferric oxide into granular activated carbon for arsenic removal.

PubMed

Jang, Min; Chen, Weifang; Cannon, Fred S

2008-05-01

Arsenic is of concern in water treatment because of its health effects. This research focused on incorporating hydrous ferric oxide (HFO) into granular activated carbon (GAC) for the purpose of arsenic removal. Iron was incorporated into GAC via incipient wetness impregnation and cured at temperatures ranging from 60 to 90 degrees C. X-ray diffractions and arsenic sorption as a function of pH were conducted to investigate the effect of temperature on final iron oxide (hydroxide) and their arsenic removal capabilities. Results revealed that when curing at 60 degrees C, the procedure successfully created HFO in the pores of GAC, whereas at temperatures of 80 and 90 degrees C, the impregnated iron oxide manifested a more crystalline form. In the column tests using synthetic water, the HFO-loaded GAC prepared at 60 degrees C also showed higher sorption capacities than media cured at higher temperatures. These results indicated that the adsorption capacity for arsenic was closely related to the form of iron (hydr)oxide for a given iron content For the column test using a natural groundwater, HFO-loaded GAC (Fe, 11.7%) showed an arsenic sorption capacity of 26 mg As/g when the influent contained 300 microg/L As. Thus, the preloading of HFO into a stable GAC media offered the opportunity to employ fixed carbon bed reactors in water treatment plants or point-of-use filters for arsenic removal.

Arsenic methylation capacity is associated with breast cancer in northern Mexico.

PubMed

López-Carrillo, Lizbeth; Hernández-Ramírez, Raúl Ulises; Gandolfi, A Jay; Ornelas-Aguirre, José Manuel; Torres-Sánchez, Luisa; Cebrian, Mariano E

2014-10-01

Exposure to environmental contaminants, dietary factors and lifestyles may explain worldwide different breast cancer (BC) incidence. Inorganic arsenic (iAs) in the drinking water is a concern in many regions, such as northern Mexico. Studies in several countries have associated the proportion of urinary monomethylarsenic (%MMA) with increased risks for many As-related diseases, including cancer. To investigate the potential relationships between the risk of BC and the capacity to methylate iAs, a hospital-based case-control study (1016 cases/1028 controls) was performed in northern Mexico. Women were directly interviewed about their reproductive histories. The profile of As metabolites in urine was determined by HPLC-ICP-MS and methylation capacity was assessed by metabolite percentages and indexes. Total urinary As, excluding arsenobetaine (TAs-AsB), ranged from 0.26 to 303.29μg/L. Most women (86%) had TAs-AsB levels below As biological exposure index (35μg/L). Women with higher %MMA and/or primary methylation index (PMI) had an increased BC risk (%MMA ORQ5vs.Q1=2.63; 95%CI 1.89,3.66; p for trend <0.001; PMI ORQ5vs.Q1=1.90; 95%CI 1.39,2.59, p for trend <0.001). In contrast, women with higher proportion of urinary dimethylarsenic (%DMA) and/or secondary methylation index (SMI) had a reduced BC risk (%DMA ORQ5vs.Q1=0.63; 95%CI 0.45,0.87, p for trend 0.006; SMI ORQ5vsQ1=0.42, 95%CI 0.31,0.59, p for trend <0.001). Neither %iAs nor total methylation index was associated to BC risk. Inter-individual variations in iAs metabolism may play a role in BC carcinogenesis. Women with higher capacity to methylate iAs to MMA and/or a lower capacity to further methylate MMA to DMA were at higher BC risk. Copyright © 2014 Elsevier Inc. All rights reserved.

Mesoporous (organo) silica decorated with magnetic nanoparticles as a reusable nanoadsorbent for arsenic removal from water samples.

PubMed

Hasanzadeh, Mohammad; Farajbakhsh, Farzad; Shadjou, Nasrin; Jouyban, Abolghasem

2015-01-01

Over the last decade, numerous removal methods using solid-supported magnetic nanocomposites have been employed in order to remove arsenic from aqueous solution. In this report, removal of arsenic from aqueous solution by an organo silica, namely, magnetic mobile crystalline material-41 (MCM-41) functionalized by chlorosulphonic acid (MMCM-41-SO3H), was investigated using atomic absorption spectroscopy. The synthesized magnetic mesoporous materials have satisfactory As (V) adsorption capacity. Linearity for arsenic was observed in the concentration range of 5-100 ppb. In addition, the coefficient of determination (R2) was more than 0.999 and the limit of detection (LOD) was 0.061 ppb. Considering these results, MMCM-41-SO3H has a great potential for the removal of As (V) contaminants and potentially for the application in large-scale wastewater treatment plants.

Sorbents for High Temperature Removal of Arsenic from Coal-Derived Synthesis Gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alptekin, G.O.; Copeland, R.; Dubovik, M.

2002-09-20

Gasification technologies convert coal and other heavy feedstocks into synthesis gas feed streams that can be used in the production of a wide variety of chemicals, ranging from hydrogen through methanol, ammonia, acetic anhydride, dimethyl ether (DME), methyl tertiary butyl ether (MTBE), high molecular weight liquid hydrocarbons and waxes. Syngas can also be burned directly as a fuel in advanced power cycles to generate electricity with very high efficiency. However, the coal-derived synthesis gas contains a myriad of trace contaminants that may poison the catalysts that are used in the downstream manufacturing processes and may also be regulated in powermore » plant emissions. Particularly, the catalysts used in the conversion of synthesis gas to methanol and other liquid fuels (Fischer-Tropsch liquids) have been found to be very sensitive to the low levels of poisons, especially arsenic, that are present in the synthesis gas from coal. TDA Research, Inc. (TDA) is developing an expendable high capacity, low-cost chemical absorbent to remove arsenic from coal-derived syngas. Unlike most of the commercially available sorbents that physically adsorb arsenic, TDA's sorbent operates at elevated temperatures and removes the arsenic through chemical reaction. The arsenic content in the coal gas stream is reduced to ppb levels with the sorbent by capturing and stabilizing the arsenic gas (As4) and arsenic hydrides (referred to as arsine, AsH3) in the solid state. To demonstrate the concept of high temperature arsenic removal from coal-derived syngas, we carried out bench-scale experiments to test the absorption capacity of a variety of sorbent formulations under representative conditions. Using on-line analysis techniques, we monitored the pre- and post-breakthrough arsine concentrations over different sorbent samples. Some of these samples exhibited pre-breakthrough arsine absorption capacity over 40% wt. (capacity is defined as lb of arsenic absorbed/lb of sorbent

The impact of a rice based diet on urinary arsenic.

PubMed

Cascio, Claudia; Raab, Andrea; Jenkins, Richard O; Feldmann, Joerg; Meharg, Andrew A; Haris, Parvez I

2011-02-01

Rice is elevated in arsenic (As) compared to other staple grains. The Bangladeshi community living in the United Kingdom (UK) has a ca. 30-fold higher consumption of rice than white Caucasians. In order to assess the impact of this difference in rice consumption, urinary arsenicals of 49 volunteers in the UK (Bangladeshi n = 37; white Caucasians n = 12) were monitored along with dietary habits. Total urinary arsenic (As(t)) and speciation analysis for dimethylarsinic acid (DMA), monomethylarsonic acid (MA) and inorganic arsenic (iAs) was conducted. Although no significant difference was found for As(t) (median: Bangladeshis 28.4 µg L(-1)) and white Caucasians (20.6 µg L(-1)), the sum of medians of DMA, MA and iAs for the Bangladeshi group was found to be over 3-fold higher (17.9 µg L(-1)) than for the Caucasians (3.50 µg L(-1)). Urinary DMA was significantly higher (p < 0.001) in the UK Bangladeshis (median: 16.9 µg DMA L(-1)) than in the white Caucasians (3.16 µg DMA L(-1)) as well as iAs (p < 0.001) with a median of 0.630 µg iAs L(-1) for Bangladeshi and 0.250 µg iAs L(-1) for Caucasians. Cationic compounds were significantly lower in the Bangladeshis (2.93 µg L(-1)) than in Caucasians (14.9 µg L(-1)). The higher DMA and iAs levels in the Bangladeshis are mainly the result of higher rice consumption: arsenic is speciated in rice as both iAs and DMA, and iAs can be metabolized, through MA, to DMA by humans. This study shows that a higher dietary intake of DMA alters the DMA/MA ratio in urine. Consequently, DMA/MA ratio as an indication of methylation capacity in populations consuming large quantities of rice should be applied with caution since variation in the quantity and type of rice eaten may alter this ratio.

Arsenic Concentrations and Speciation in Shellfishes from Korea

NASA Astrophysics Data System (ADS)

Yoon, C.; Yoon, H.

2005-12-01

Speciation of arsenic has received significant attention over the past 20 years in both mechanistic and exposure assessment research. Because the toxicity of arsenic is related to its oxidation state and its chemical forms, the determination of the total arsenic contents in a sample is not adequate to allow its impact on living organisms to be estimated. The inorganic arsenic species, arsenite (As3+) and arsenate (As5+), have been classified as carcinogenic and the methylated forms, monomethyl arsonic acid (MMA) and dimethyl arsinic acid (DMA) have recently been identified as cancer promoters. The highly methylated compounds like as arsenobetaine (AsB) and arsenocholine (AsC) are considered to be nontoxic. Although organisms in marine environment contain high amounts of total arsenic (ppm level), it is not usually present as inorganic arsenic or simple methylated forms well known as one of the toxic species. Arsenobetaine is the dominant species in marine animals and arsenosugars are most abundant in marine algae. This study aims to clarify those arsenic species present in the whole body of eleven different shellfishes from Korea. And those arsenic species were separated and measured by characterization using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) coupled system. The separation of arsenic species was achieved on anion exchange column and cation exchange column using phosphate and pyridine eluent, respectively. The ultrasonic extraction was employed for extraction of arsenic from whole body of shellfishes. The method was validated by analyzing three certified reference materials (DORM-2, TORT-2, 1566b). Total arsenic concentrations ranged from 0.1 mg/kg dry mass to 21.7 mg/kg dry mass. Most marine shellfishes contained higher arsenobetaine and arsenocholine with the exception of two shellfishes living in river. The lower amounts of inorganic arsenic species were also found in the some sample extracts

Sequestration of arsenic in ombrotrophic peatlands

NASA Astrophysics Data System (ADS)

Rothwell, James; Hudson-Edwards, Karen; Taylor, Kevin; Polya, David; Evans, Martin; Allott, Tim

2014-05-01

Peatlands can be important stores of arsenic but we are lacking spectroscopic evidence of the sequestration pathways of this toxic metalloid in peatland environments. This study reports on the solid-phase speciation of anthropogenically-derived arsenic in atmospherically contaminated peat from the Peak District National Park (UK). Surface and sub-surface peat samples were analysed by synchrotron X-ray absorption spectroscopy on B18 beamline at Diamond Light Source (UK). The results suggest that there are contrasting arsenic sequestration mechanisms in the peat. The bulk arsenic speciation results, in combination with strong arsenic-iron correlations at the surface, suggest that iron (hydr)oxides are key phases for the immobilisation of arsenic at the peat surface. In contrast, the deeper peat samples are dominated by arsenic sulphides (arsenopyrite, realgar and orpiment). Given that these peats receive inputs solely from the atmosphere, the presence of these sulphide phases suggests an in-situ authigenic formation. Redox oscillations in the peat due to a fluctuating water table and an abundant store of legacy sulphur from historic acid rain inputs may favour the precipitation of arsenic sequestering sulphides in sub-surface horizons. Oxidation-induced loss of these arsenic sequestering sulphur species by water table drawdown has important implications for the mobility of arsenic and the quality of waters draining peatlands.

Polymorphism of inflammatory genes and arsenic methylation capacity are associated with urothelial carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Chia-Chang; Department of Urology, Taipei Medical University—Shuang Ho Hospital, Taipei, Taiwan; Huang, Yung-Kai

2013-10-01

Chronic exposure to arsenic can generate reactive oxidative species, which can induce certain proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8). TNF-α, IL-6 and IL-8 have been shown to be involved in the development and progression of various cancers, including bladder cancer. This study aimed to investigate the joint effect of the polymorphism of TNF-α − 308 G/A, IL-6 − 174 G/C, IL-8 − 251 T/A and urinary arsenic profiles on urothelial carcinoma (UC) risk. This study evaluated 300 pathologically-confirmed cases of UC and 594 cancer-free controls. Urinary arsenic species were detected using high-performance liquidmore » chromatography-linked hydride generator and atomic absorption spectrometry. The polymorphism of TNF-α − 308 G/A, IL-6 − 174 G/C and IL-8 − 251 T/A was determined using polymerase chain reaction-restriction fragment length polymorphism. The joint effects on UC risk were estimated by odds ratios and 95% confidence intervals using unconditional logistic regression. We found that the TNF-α − 308 A/A and IL-8 − 251 T/T polymorphisms were significantly associated with UC. Moreover, significant dose–response joint effect of TNF-α − 308 A/A or IL-8 − 251 T/T genotypes and arsenic methylation indices were seen to affect UC risk. The present results also showed a significant increase in UC risk in subjects with the IL-8 − 251 T/T genotype for each SD increase in urinary total arsenic and MMA%. In contrast, a significant decrease in UC risk was found in subjects who carried the IL-8 − 251 T/T genotype for each SD increase in DMA%. - Highlights: • Joint effect of the TNF-α -308 A/A genotype and urinary total arsenic affected UC. • Joint effect of the IL-8 -251 T/T genotype and urinary total arsenic affected UC. • Urinary total arsenic level, TNF-α -308 A/A and IL-8 -251 T/T genotype affected UC.« less

Application of AMDS mortar as a treatment agent for arsenic in subsurface environment

NASA Astrophysics Data System (ADS)

Choi, J.; Lee, H.; Choi, U. K.; Yang, I. J.

2014-12-01

Among the treatment technologies available for As in soil and groundwater, adsorption or precipitation using acid mine drainage (AMD) sludge has become a promised technique because of high efficiency, inexpensiveness and simple to handling. The adsorbents were prepared by addition of Cement, Joomoonjin sand, fly ash, and Ca(OH)2 to air dry AMD sludge. In this work, the adsorption of As (III) and As (V) on AMDS mortar has been studied as a function of kinetic, pH, and initial arsenic concentration. Results of batch study showed that 75-90% of both As (III) and As (V) were removed at pH 7. Arsenic adsorption capacities were the highest at neutral pH condition and the adsorption equilibrium time reached in 7 days using AMDS mortar. Additionally, the adsorption kinetic process is expressed well by pseudo-second-order model. The adsorption capacities of AMDS mortar for As(III) and As(V) were found 19.04 and 30.75 mg g-1, respectively. The results of As (III) adsorption isotherms were fitted well to the Freundlich model. Moreover, As (V) adsorption isotherms were fitted well to the Langmuir model rather than Freundlich model. Based on experimental results in this study, we could conclude that AMDS mortar can be effectively used for arsenic removal agent from subsurface environment.

Benefits of Alcohol on Arsenic Toxicity in Rats

PubMed Central

Dutta, Shubha Ranjan; Passi, Deepak; Bharti, Jaya

2017-01-01

Introduction It has been demonstrated earlier that exposure to ethanol and/or arsenic compounds (such as sodium arsenite) produces toxic effects as shown by both in vitro and in vivo experiments. Chronic exposure of humans to arsenic through drinking water, pesticides or consumption of alcoholic beverages has produced major health problem and concern in recent years. Water being one of the main ingredients for alcohol formation (beer fermentation process) can lead to contamination with arsenic. Thus, people consuming such alcohol are getting continuously exposed to arsenic compounds as well along with alcohol. Aim The present study was undertaken to investigate the effect of alcohol co-administration on arsenic induced changes in carbohydrate metabolic status in adult male albino rats. Materials and Methods Adult male albino rats of Wistar strain (weighing~100g) were divided into three groups (n=8 rats/group) including Control or vehicle treated (C), Arsenic treated (As) and Arsenic treated alcohol co-exposed (As+Alc). Treatment with Sodium-arsenite included intra-peritoneal injection consecutively for 14 days at a dose of 5.55 mg/kg (equivalent to 35% of LD50) per day. Absolute alcohol (15% v/v) was fed at a dose of 0.5 ml/100 g body weight per day for five consecutive days from start of the treatment schedule. Distilled water (D/W) was used as vehicle. Blood Glucose (BG) level, levels of glycogen, Pyruvic Acid (PA), Free Amino Acid Nitrogen (FAAN), total protein, Glutamate Oxalate transaminase (GOT) and Glutamate Pyruvate Transaminase (GPT) activity, and glucose-6-phosphatase (G6Pase) activity were measured in tissues including liver, kidney and muscle. Results Treatment with arsenic decreased the levels of BG, liver glycogen and PA, tissue protein and G6Pase activity, GOT activity in liver and muscle, and increased free amino acid content in kidney and muscle, GPT activity in liver and kidney. Alcohol administration to rats co-exposed to arsenic treatment

Benefits of Alcohol on Arsenic Toxicity in Rats.

PubMed

Singh, Purnima; Dutta, Shubha Ranjan; Passi, Deepak; Bharti, Jaya

2017-01-01

It has been demonstrated earlier that exposure to ethanol and/or arsenic compounds (such as sodium arsenite) produces toxic effects as shown by both in vitro and in vivo experiments. Chronic exposure of humans to arsenic through drinking water, pesticides or consumption of alcoholic beverages has produced major health problem and concern in recent years. Water being one of the main ingredients for alcohol formation (beer fermentation process) can lead to contamination with arsenic. Thus, people consuming such alcohol are getting continuously exposed to arsenic compounds as well along with alcohol. The present study was undertaken to investigate the effect of alcohol co-administration on arsenic induced changes in carbohydrate metabolic status in adult male albino rats. Adult male albino rats of Wistar strain (weighing~100g) were divided into three groups (n=8 rats/group) including Control or vehicle treated (C), Arsenic treated (As) and Arsenic treated alcohol co-exposed (As+Alc). Treatment with Sodium-arsenite included intra-peritoneal injection consecutively for 14 days at a dose of 5.55 mg/kg (equivalent to 35% of LD50) per day. Absolute alcohol (15% v/v) was fed at a dose of 0.5 ml/100 g body weight per day for five consecutive days from start of the treatment schedule. Distilled water (D/W) was used as vehicle. Blood Glucose (BG) level, levels of glycogen, Pyruvic Acid (PA), Free Amino Acid Nitrogen (FAAN), total protein, Glutamate Oxalate transaminase (GOT) and Glutamate Pyruvate Transaminase (GPT) activity, and glucose-6-phosphatase (G6Pase) activity were measured in tissues including liver, kidney and muscle. Treatment with arsenic decreased the levels of BG, liver glycogen and PA, tissue protein and G6Pase activity, GOT activity in liver and muscle, and increased free amino acid content in kidney and muscle, GPT activity in liver and kidney. Alcohol administration to rats co-exposed to arsenic treatment reversed these changes. Thus, it is suggested that

Uric acid contributes greatly to hepatic antioxidant capacity besides protein.

PubMed

Mikami, T; Sorimachi, M

2017-12-20

Uric acid is the end-product of purine nucleotide metabolism and an increase in uric acid concentration in the body results in hyperuricemia, ultimately leading to gout. However, uric acid is a potent antioxidant and interacts with reactive oxygen species (ROS) to be non-enzymatically converted to allantoin. Uric acid accounts for approximately 60 % of antioxidant capacity in the plasma; however, its contribution to tissue antioxidant capacity is unknown. In this study, the contribution of uric acid to tissue antioxidant capacity and its conversion to allantoin by scavenging ROS in tissue were examined. The results showed that a decrease in hepatic uric acid content via allopurinol administration significantly reduced hepatic total-radical trapping antioxidant parameter (TRAP) content in protein-free cytosol. Additionally, treating protein-free cytosol with uricase led to a further reduction of hepatic TRAP content. Allantoin was also detected in the solution containing protein-free cytosol that reacted with ROS. These findings suggest that in the absence of protein, uric acid contributes greatly to antioxidant capacity in the liver, where uric acid is converted to allantoin by scavenging ROS.

Effect of the Aqueous Extract of Lantana grisebachii Stuck Against Bioaccumulated Arsenic-Induced Oxidative and Lipid Dysfunction in Rat Splenocytes.

PubMed

Ramos Elizagaray, Sabina I; Quiroga, Patricia L; Pérez, Roberto D; Sosa, Carlos; Pérez, Carlos A; Bongiovanni, Guillermina A; Soria, Elio A

2018-06-29

Arsenic (As) is a worldwide immunotoxic agent that is in contaminated waters and consumed by mammals. Phytotherapy may counteract its harmful effects. Lantana grisebachii Stuck (LG, Verbenaceae) and its extract are proposed as protective, given vvits in vitro bioactivity. The aim was to determine the protective capacity of the aqueous LG extract on splenocytes exposed in vivo to arsenic. Splenocytes were obtained from an arsenicosis model (Wistar rats consuming orally 0 [control; C] or 5 mg/Kg/d of As) that received 0-100 mg/Kg/d of LG extract for 30 days. As content (total reflection X-ray fluorescence), fatty acid profile (gas chromatography), γ-glutamyl transpeptidase activity (Szasz method), peroxides (xylenol orange-based assay), and nitrites (Griess reaction) were then assayed in viable splenocytes. Data were analyzed with ANOVA and the Tukey's test (p < .05). It was observed that the splenocytes contained 2.2 mg/Kg of this elemental arsenic. With γ-glutamyl transpeptidase inhibition and consequent triggering of hydroperoxides (p < .05), it was observed to increase saturated fatty acids and alter lipid profiles. LG treatment avoided damaging effects with values similar to unexposed C (p < .05), and cellular arsenic concentration (p < .0001). In conclusion, the aqueous extract of L. grisebachii counteracted arsenic toxicity in rat splenocytes by preventing its cellular accumulation and induction of lipid and redox disturbances, which may impair immune function.

All-trans retinoic acid protects against arsenic-induced uterine toxicity in female Sprague-Dawley rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatterjee, A.; Chatterji, U., E-mail: urmichatterji@gmail.com

2011-12-15

Background and purpose: Arsenic exposure frequently leads to reproductive failures by disrupting the rat uterine histology, hormonal integrity and estrogen signaling components of the rat uterus, possibly by generating reactive oxygen species. All-trans retinoic acid (ATRA) was assessed as a prospective therapeutic agent for reversing reproductive disorders. Experimental approach: Rats exposed to arsenic for 28 days were allowed to either recover naturally or were treated simultaneously with ATRA for 28 days or treatment continued up to 56 days. Hematoxylin-eosin double staining was used to evaluate changes in the uterine histology. Serum gonadotropins and estradiol were assayed by ELISA. Expression ofmore » the estrogen receptor (ER{alpha}), an estrogen responsive gene vascular endothelial growth factor (VEGF), and cell cycle regulatory proteins, cyclin D1 and CDK4, was assessed by RT-PCR, immunohistochemistry and western blot analysis. Key results: ATRA ameliorated sodium arsenite-induced decrease in circulating estradiol and gonadotropin levels in a dose- and time-dependent manner, along with recovery of luminal epithelial cells and endometrial glands. Concomitant up regulation of ER{alpha}, VEGF, cyclin D1, CDK4 and Ki-67 was also observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Conclusions and implications: Collectively, the results reveal that ATRA reverses arsenic-induced disruption of the circulating levels of gonadotropins and estradiol, and degeneration of luminal epithelial cells and endometrial glands of the rat uterus, indicating resumption of their functional status. Since structural and functional maintenance of the pubertal uterus is under the influence of estradiol, ATRA consequently up regulated the estrogen receptor and resumed cellular proliferation, possibly by an antioxidant therapeutic approach against arsenic toxicity. Highlights: Black

A critical review of the arsenic uptake mechanisms and phytoremediation potential of Pteris vittata.

PubMed

Danh, Luu Thai; Truong, Paul; Mammucari, Raffaella; Foster, Neil

2014-01-01

The discovery of the arsenic hyperaccumulator, Pteris vittata (Chinese brake fern), has contributed to the promotion of its application as a means of phytoremediation for arsenic removal from contaminated soils and water. Understanding the mechanisms involved in arsenic tolerance and accumulation of this plant provides valuable tools to improve the phytoremediation efficiency. In this review, the current knowledge about the physiological and molecular mechanisms of arsenic tolerance and accumulation in P. vittata is summarized, and an attempt has been made to clarify some of the unresolved questions related to these mechanisms. In addition, the capacity of P. vittata for remediation of arsenic-contaminated soils is evaluated under field conditions for the first time, and possible solutions to improve the remediation capacity of Pteris vittata are also discussed.

Arsenic speciation in fish from Greek coastal areas.

PubMed

Kalantzi, Ioanna; Mylona, Kyriaki; Sofoulaki, Katerina; Tsapakis, Manolis; Pergantis, Spiros A

2017-06-01

Arsenic speciation analysis was conducted on fish samples (sardine and anchovy) collected from six areas along the Greek coastline, i.e. Artemisium Straits, Thermaikos Gulf, Amvrakikos Gulf, Strymonian Gulf, Thracian Sea, and Elefsina Gulf. Total arsenic levels ranging from 11.8 to 62.6mg As/kg dry weight were determined. Arsenobetaine, a non-toxic form of arsenic, was found to be the main arsenic species, present at 8.6 to 58.8mg As/kg dry weight, accounting for 67-95% of the total arsenic. Also detected in all fish samples was dimethylarsinic acid, although at considerably lower concentrations, ranging from 0.072-0.956mg As/kg dry weight. Monomethylarsonic acid was detected at low levels in all anchovy samples, and only in sardines from one area. Finally, inorganic arsenic in the form of arsenate was detected only in fish at one area, indicating the possible effect of an environmental parameter on its presence at detectable amounts. Statistical analysis revealed the environmental variables, such as salinity, total organic carbon and nitrogen, ammonium, phosphate, total phosphorus, dissolved oxygen and pressure index, are potentially correlated to As species concentrations. Furthermore, based on factor analysis, the biological parameters, such as fish weight, lipids, protein and ash content, that are correlated to As species concentrations of fish were also identified. The interrelationship of arsenobetaine and dimethylarsinic acid concentrations within each fish species was evaluated. Copyright © 2017. Published by Elsevier B.V.

Sample preparation and storage can change arsenic speciation in human urine.

PubMed

Feldmann, J; Lai, V W; Cullen, W R; Ma, M; Lu, X; Le, X C

1999-11-01

Stability of chemical speciation during sample handling and storage is a prerequisite to obtaining reliable results of trace element speciation analysis. There is no comprehensive information on the stability of common arsenic species, such as inorganic arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid, dimethylarsinic acid, and arsenobetaine, in human urine. We compared the effects of the following storage conditions on the stability of these arsenic species: temperature (25, 4, and -20 degrees C), storage time (1, 2, 4, and 8 months), and the use of additives (HCl, sodium azide, benzoic acid, benzyltrimethylammonium chloride, and cetylpyridinium chloride). HPLC with both inductively coupled plasma mass spectrometry and hydride generation atomic fluorescence detection techniques were used for the speciation of arsenic. We found that all five of the arsenic species were stable for up to 2 months when urine samples were stored at 4 and -20 degrees C without any additives. For longer period of storage (4 and 8 months), the stability of arsenic species was dependent on urine matrices. Whereas the arsenic speciation in some urine samples was stable for the entire 8 months at both 4 and -20 degrees C, other urine samples stored under identical conditions showed substantial changes in the concentration of As(III), As(V), monomethylarsonic acid, and dimethylarsinic acid. The use of additives did not improve the stability of arsenic speciation in urine. The addition of 0.1 mol/L HCl (final concentration) to urine samples produced relative changes in inorganic As(III) and As(V) concentrations. Low temperature (4 and -20 degrees C) conditions are suitable for the storage of urine samples for up to 2 months. Untreated samples maintain their concentration of arsenic species, and additives have no particular benefit. Strong acidification is not appropriate for speciation analysis.

Effects of biological and behavioral factors on urinary arsenic ...

EPA Pesticide Factsheets

Abstract In older men and women who were long-term residents of Churchill County, Nevada, we examined the relation between arsenic exposure from home tap water and urinary levels of inorganic arsenic and its methylated metabolites. Over a wide exposure range (up to 1850 ug of arsenic per liter), urinary concentrations of inorganic, monomethylated, and dimethylated arsenicals strongly correlated with home tap water arsenic concentrations. However, percentages of summed urinary concentrations of inorganic, monomethylated, and dimethylated arsenicals accounted for by each arsenical species were unaffected by arsenic concentration in home tap water, suggesting thc1t capacity for formation and excretion of methylated metabolites was not exceeded. Biological factors (gender, age, body mass index, and genotype) and a behavioral factor (smoking) influenced absolute and relative levels of arsenicals in urine. A multivariate regression model showed that both biological and behavioral factors were significant predictors of absolute and relative concentrations of inorganic arsenic and its methylated metabolites in urine. These findings suggest that analyses of dose-response relations in arsenic-exposed populations should account for these biological and behavioral factors. Furthermore, evidence of significant effects of these factors on arsenic metabolism may support mode of action studies in appropriate experimental models. Running title- Methylated arsenicals as urinary b

Phytoremediation of arsenic in submerged soil by wetland plants.

PubMed

Jomjun, Nateewattana; Siripen, Trichaiyaporn; Maliwan, Saeouy; Jintapat, Nateewattana; Prasak, Thavornyutikarn; Somporn, Choonluchanon; Petch, Pengchai

2011-01-01

Wetland aquatic plants including Canna glauca L., Colocasia esculenta L. Schott, Cyperus papyrus L. and Typha angustifolia L. were used in the phytoremediation of submerged soil polluted by arsenic (As). Cyperus papyrus L. was noticed as the largest biomass producer which has arsenic accumulation capacity of 130-172 mg As/kg plant. In terms of arsenic removal rate, however, Colocasia esculenta L. was recognized as the largest and fastest arsenic remover in this study. Its arsenic removal rate was 68 mg As/m2/day while those rates of Canna glauca L., Cyperus papyrus L. and Typha angustifolia L. were 61 mg As/m2/day, 56 mg As/m2/day, and 56 mg As/m2/day, respectively. Although the 4 aquatic plants were inferior in arsenic accumulation, their high arsenic removal rates were observed. Phytostabilization should be probable for the application of these plants.

Environmentally relevant dose of arsenic interferes in functions of human monocytes derived dendritic cells.

PubMed

Bahari, Abbas; Salmani, Vahid

2017-06-05

Arsenic is a major environmental pollutant and highly hazardous toxin to human health, which well established as carcinogen and immune deregulatory properties. Dendritic cells (DCs) have a pivotal role in cell-mediated immunity for T-cell activation and antigen presentation. In this study, T cell activation, some key functional genes expression, cell stability and phagocytosis capacity of human monocytes derived DCs (MDDCs) were analyzed after in vitro exposure to very low dose of arsenic for 12 and 24h. Arsenic decreased continually phagocytosis capacity of MDDCs. Furthermore, down-regulation of the cell-surface expression of the co-stimulatory molecule CD40 after 24h post treatment with arsenic, confirmed arsenic interferers in the phagocytosis process. Pro inflammatory cytokines, IL1β and TNFα were more expressed in arsenic-treated MDDCs while IL6 transiently was down regulated. In general, our novel findings here strongly suggest that low level of arsenic dysregulates four fundamental immune processes of DCs. Mechanistically; this could explain the observed immunodeficiency activity of Arsenic, and give direction for comprehension the pathogenesis of Arsenic-induced diseases. Copyright © 2017. Published by Elsevier B.V.

[Study on the variation of arsenic concentration in groundwater and chemical characteristics of arsenic in sediment cores at the areas with endemic arsenic poison disease in Jianghan Plain].

PubMed

Zhou, Suhua; Ye, Hengpeng; Li, Mingjian; Xiong, Peisheng; Du, Dongyun; Wang, Jingwen

2015-06-01

To understand the variation of arsenic concentration in underground water at the endemic arsenic poison disease area of Jianghan Plain so as to better understand the spatial distribution of high arsenic groundwater, hydro-chemical evolution and source of arsenic in this region. Thirty underground water samples were collected respectively around 3 km radius of the two houses where arsenic poisoning patients lived, in Xiantao and Honghu. Sediment cores of three drillings were collected as well. Both paired t-test or paired Wilcoxon Signed Ranking Test were used to compare the arsenic concentration of water. The arsenic concentration in 2011-2012 appeared lower than that in 2006-2007 at the Nanhong village of Xiantao (t = 4.645 3, P < 0.000 1), but was higher (S = -150, P < 0.000 1) in the Yaohe village of Honghu. The pH value showed weak acidity with Eh as weak oxidated. Positive correlations were observed between arsenic concentration and Cl, HCO3(-), Fe, Mn. However, negative correlations were found between As and SO4(2-), NO3(-). The range of arsenic content in the sediment was 1.500 mg/kg to 17.289 mg/kg. The maximum arsenic content existed in the soil layer, while the minimum arsenic content existed in the sand layer. The concentration of arsenic varied widely with time and space at endemic arsenic poison disease area of Jianghan Plain. Characteristics of these water chemicals showed significant differences, when compared to the groundwater from Datong Basin, Shanxi Shanyin and Hetao Plain of Inner Mongolia, which presented a typical environment with high arsenic contents in the groundwater. The arsenic content in the sediment samples seemed related to the lithologic structure.

Human exposure to arsenic from drinking water in Vietnam.

PubMed

Agusa, Tetsuro; Trang, Pham Thi Kim; Lan, Vi Mai; Anh, Duong Hong; Tanabe, Shinsuke; Viet, Pham Hung; Berg, Michael

2014-08-01

Vietnam is an agricultural country with a population of about 88 million, with some 18 million inhabitants living in the Red River Delta in Northern Vietnam. The present study reports the chemical analyses of 68 water and 213 biological (human hair and urine) samples conducted to investigate arsenic contamination in tube well water and human arsenic exposure in four districts (Tu Liem, Dan Phuong, Ly Nhan, and Hoai Duc) in the Red River Delta. Arsenic concentrations in groundwater in these areas were in the range of <1 to 632 μg/L, with severe contamination found in the communities Ly Nhan, Hoai Duc, and Dan Phuong. Arsenic concentrations were markedly lowered in water treated with sand filters, except for groundwater from Hoai Duc. Human hair samples had arsenic levels in the range of 0.07-7.51 μg/g, and among residents exposed to arsenic levels ≥50 μg/L, 64% of them had hair arsenic concentrations higher than 1 μg/g, which is a level that can cause skin lesions. Urinary arsenic concentrations were 4-435 μg/g creatinine. Concentrations of arsenic in hair and urine increased significantly with increasing arsenic content in drinking water, indicating that drinking water is a significant source of arsenic exposure for these residents. The percentage of inorganic arsenic (IA) in urine decreased with age, whereas the opposite trend was observed for monomethylarsonic acid (MMA) in urine. Significant co-interactions of age and arsenic exposure status were also detected for concentrations of arsenic in hair and the sum of IA, MMA, and dimethylarsinic acid (DMA) in urine and %MMA. In summary, this study demonstrates that a considerable proportion of the Vietnamese population is exposed to arsenic levels of chronic toxicity, even if sand filters reduce exposure in many households. Health problems caused by arsenic ingestion through drinking water are increasingly reported in Vietnam. © 2013 Elsevier B.V. All rights reserved.

Recent advances in exploitation of nanomaterial for arsenic removal from water: a review

NASA Astrophysics Data System (ADS)

Wong, WeiWen; Wong, H. Y.; Badruzzaman, A. Borhan M.; Goh, H. H.; Zaman, Mukter

2017-01-01

Recently, increasing research efforts have been made to exploit the enormous potential of nanotechnology and nanomaterial in the application of arsenic removal from water. As a result, there are myriad of types of nanomaterials being developed and studied for their arsenic removal capabilities. Nevertheless, challenges such as having a complete understanding of the material properties and removal mechanism make it difficult for researchers to engineer nanomaterials that are best suited for specific water treatment applications. In this review paper, a comprehensive review will be conducted on several selected categories of nanomaterials that possess promising prospects in arsenic removal application. The synthesis process, material properties, as well as arsenic removal performance and removal mechanisms of each of these nanomaterials will be discussed in detail. Fe-based nanomaterials, particularly iron oxide nanoparticles, have displayed advantages in arsenic removal due to their super-paramagnetic property. On the other hand, TiO2-based nanomaterials are the best candidates as photocatalytic arsenic removal agents, having been reported to have more than 200-fold increase in adsorption capacity under UV light irradiation. Zr-based nanomaterials have among the largest BET active area for adsorption—up to 630 m2 g-1—and it has been reported that amorphous ZrO2 performs better than crystalline ZrO2 nanoparticles, having about 1.77 times higher As(III) adsorption capacity. Although Cu-based nanomaterials are relatively uncommon as nano-adsorbents for arsenic in water, recent studies have demonstrated their potential in arsenic removal. CuO nanoparticles synthesized by Martinson et al were reported to have adsorption capacities up to 22.6 mg g-1 and 26.9 mg g-1 for As(V) and As(III) respectively. Among the nanomaterials that have been reviewed in this study, Mg-based nanomaterials were reported to have the highest maximum adsorption capacities for As(V) and As

Analysis of Factors Influencing Soil Salinity, Acidity, and Arsenic Concentration in a Polder in Southwest Bangladesh

NASA Astrophysics Data System (ADS)

Ayers, J. C.; Patton, B.; Fry, D. C.; Goodbred, S. L., Jr.

2017-12-01

Soil samples were collected on Polder 32 in the coastal zone of SW Bangladesh in wet (October) and dry (May) seasons from 2013-2017 and analyzed to characterize the problems of soil salinization and arsenic contamination and identify their causes. Soils are entisols formed from recently deposited, predominantly silt-sized sediments with low carbon concentrations typical of the local mangrove forests. Soluble (DI extract) arsenic concentrations were below the Government of Bangladesh limit of 50 ppb for drinking water. Soil acidity and extract arsenic concentrations exhibit spatial variation but no consistent trends. In October soil extract As is higher and S and pH are lower than in May. These observations suggest that wet season rainwater oxidizes pyrite, reducing soil S and releasing H+, causing pH to decrease. Released iron is oxidized to form Hydrous Ferric Oxyhydroxides (HFOs), which sorb As and increase extractable As in wet season soils. Changes in pH are small due to pH buffering by soil carbonates. Soil and rice paddy water salinities are consistently higher in May than October, reaching levels in May that reduce rice yields. Rice grown in paddies should be unaffected by salt concentrations in the wet season, while arsenic concentrations in soil may be high enough to cause unsafe As levels in produced rice.

Removal of arsenic from synthetic acid mine drainage by electrochemical pH adjustment and coprecipitation with iron hydroxide.

PubMed

Wang, Jenny Weijun; Bejan, Dorin; Bunce, Nigel J

2003-10-01

Acid mine drainage (AMD), which is caused by the biological oxidation of sulfidic materials, frequently contains arsenic in the form of arsenite, As(III), and/or arsenate, As(V), along with much higher concentrations of dissolved iron. The present work is directed toward the removal of arsenic from synthetic AMD by raising the pH of the solution by electrochemical reduction of H+ to elemental hydrogen and coprecipitation of arsenic with iron(III) hydroxide, following aeration of the catholyte. Electrolysis was carried out at constant current using two-compartment cells separated with a cation exchange membrane. Four different AMD model systems were studied: Fe(III)/As(V), Fe(III)/As(III), Fe(II)/As(V), and Fe(II)/As(III) with the initial concentrations for Fe(III) 260 mg/L, Fe(II) 300 mg/L, As(V), and As(III) 8 mg/L. Essentially quantitative removal of arsenic and iron was achieved in all four systems, and the results were independent of whether the pH was adjusted electrochemically or by the addition of NaOH. Current efficiencies were approximately 85% when the pH of the effluent was 4-7. Residual concentrations of arsenic were close to the drinking water standard proposed by the World Health Organization (10 microg/L), far below the mine waste effluent standard (500 microg/L).

Urinary total arsenic and 8-hydroxydeoxyguanosine are associated with renal cell carcinoma in an area without obvious arsenic exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Chao-Yuan; Department of Urology, National Taiwan University Hospital, College of Medicine National Taiwan University, Taipei, Taiwan; Su, Chien-Tien

2012-08-01

8-Hydroxydeoxyguanosine (8-OHdG) is one of the most reliable and abundant markers of DNA damage. The study was designed to explore the relationship between urinary 8-OHdG and renal cell carcinoma (RCC) and to investigate whether individuals with a high level of 8-OHdG would have a modified odds ratio (OR) of arsenic-related RCC. This case–control study was conducted with 132 RCC patients and 245 age- and sex-matched controls from a hospital-based pool between November 2006 and May 2009. Pathological verification of RCC was completed by image-guided biopsy or surgical resection of renal tumors. Urinary 8-OHdG levels were determined using liquid chromatography withmore » tandem mass spectrometry (LC–MS/MS). Concentrations of urinary arsenic species, including inorganic arsenic, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), were determined by a high performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. Level of urinary 8-OHdG was significantly associated with the OR of RCC in a dose–response relationship after multivariate adjustment. Urinary 8-OHdG was significantly related to urinary total arsenic. The greatest OR (3.50) was seen in the individuals with high urinary 8-OHdG and high urinary total arsenic. A trend test indicated that the OR of RCC was increased with one of these factors and was further increased with both (p = 0.002). In conclusion, higher urinary 8-OHdG was a strong predictor of the RCC. High levels of 8-OHdG combined with urinary total arsenic might be indicative of arsenic-induced RCC. -- Highlights: ► Urinary 8-OHdG was significantly related to urinary total arsenic. ► Higher urinary 8-OHdG was a strong predictor of RCC risk. ► Urinary 8-OHdG may modify arsenic related RCC risk.« less

Effects of exogenous glutathione on arsenic burden and NO metabolism in brain of mice exposed to arsenite through drinking water.

PubMed

Wang, Yan; Zhao, Fenghong; Jin, Yaping; Zhong, Yuan; Yu, Xiaoyun; Li, Gexin; Lv, Xiuqiang; Sun, Guifan

2011-03-01

Chronic exposure to inorganic arsenic (iAs) is associated with neurotoxicity. Studies to date have disclosed that methylation of ingested iAs is the main metabolic pathway, and it is a process relying on reduced glutathione (GSH). The aim of this study was to explore the effects of exogenous GSH on arsenic burden and metabolism of nitric oxide (NO) in the brain of mice exposed to arsenite via drinking water. Mice were exposed to sodium arsenite through drinking water contaminated with 50 mg/L arsenic for 4 weeks and treated intraperitoneally with saline solution, 200 mg/kg body weight (b.w), 400 mg/kg b.w, or 800 mg/kg b.w GSH, respectively, at the 4th week. Levels of iAs, monomethylarsenic acid, and dimethylarsenic acid (DMAs) in the liver, blood, and brain were determined by method of hydride generation coupled with atomic absorption spectrophotometry. Activities of nitric oxide synthase (NOS) and contents of NO in the brain were determined by colorimetric method. Compared with mice exposed to arsenite alone, administration of GSH increased dose-dependently the primary and secondary methylation ratio in the liver, which caused the decrease in percent iAs and increase in percent DMAs in the liver, as a consequence, resulted in significant decrease in iAs levels in the blood and total arsenic levels in both blood and brain. NOS activities and NO levels in the brain of mice in iAs group were significantly lower than those in control; however, administration of GSH could increase significantly activities of NOS and contents of NO. Findings from this study suggested that exogenous GSH could promote both primary and secondary arsenic methylation capacity in the liver, which might facilitate excretion of arsenicals, and consequently reduce arsenic burden in both blood and brain and furthermore ameliorate the effects of arsenicals on NO metabolism in the brain.

Concentrations of urinary arsenic species in relation to rice and seafood consumption among children living in Spain.

PubMed

Signes-Pastor, Antonio J; Vioque, Jesus; Navarrete-Muñoz, Eva M; Carey, Manus; García de la Hera, Manoli; Sunyer, Jordi; Casas, Maribel; Riaño-Galán, Isolina; Tardón, Adonina; Llop, Sabrina; Amorós, Rubén; Amiano, Pilar; Bilbao, José R; Karagas, Margaret R; Meharg, Andrew A

2017-11-01

Inorganic arsenic (i-As) has been related to wide-ranging health effects in children, leading to lifelong concerns. Proportionally, dietary i-As exposure dominates in regions with low arsenic drinking water. This study aims to investigate the relation between rice and seafood consumption and urinary arsenic species during childhood and to assess the proportion of urinary i-As metabolites. Urinary arsenic species concentration in 400 4-year-old children living in four geographical areas of Spain, in addition to repeated measures from 100 children at 7 years of age are included in this study. Rice and seafood products intake was collected from children's parents using a validated food frequency questionnaire (FFQ). At 4 years of age, children's urine i-As and monomethylarsonic acid (MMA) concentrations increased with rice product consumption (p-value = 0.010 and 0.018, respectively), and urinary arsenobetaine (AsB) with seafood consumption (p = 0.002). Four-year-old children had a higher consumption of both rice and seafood per body weight and a higher urinary %MMA (p-value = 0.001) and lower % dimethylarsinic acid (DMA) (p-value = 0.017). This study suggests increased dietary i-As exposure related to rice product consumption among children living in Spain, and the younger ones may be especially vulnerable to the health impacts of this exposure also considering that they might have a lower i-As methylation capacity than older children. In contrast, seafood consumption did not appear to influence the presence of potentially toxic arsenic species in this population of children. Copyright © 2017 Elsevier Inc. All rights reserved.

Soil properties influence kinetics of soil acid phosphatase in response to arsenic toxicity.

PubMed

Wang, Ziquan; Tan, Xiangping; Lu, Guannan; Liu, Yanju; Naidu, Ravi; He, Wenxiang

2018-01-01

Soil phosphatase, which plays an important role in phosphorus cycling, is strongly inhibited by Arsenic (As). However, the inhibition mechanism in kinetics is not adequately investigated. In this study, we investigated the kinetic characteristics of soil acid phosphatase (ACP) in 14 soils with varied properties, and also explored how kinetic properties of soil ACP changed with different spiked As concentrations. The results showed that the Michaelis constant (K m ) and maximum reaction velocity (V max ) values of soil ACP ranged from 1.18 to 3.77mM and 0.025-0.133mMh -1 in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K m remained unchanged and V max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K m increased linearly and V max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K ic ) and noncompetitive inhibition constant (K iu ) varied among soils and ranged from 0.38 to 3.65mM and 0.84-7.43mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V max /K m ) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

Potential impact of acid precipitation on arsenic and selenium.

PubMed Central

Mushak, P

1985-01-01

The potential impact of acidic precipitation on the environmental mobility of the metalloids arsenic (As) and selenium (Se) has not been given much attention and is poorly understood. As with other elements, the interest here is the potential effect of environmental acidification on environmental behavior in ways that are relevant to human exposure to these metalloids. Available information on acid precipitation and the environmental behavior of these metalloids do, however, permit some preliminary conclusions to be drawn. Both As and Se appear to be mobilized from household plumbing into tap water by the corrosive action of soft, mildly acidic water, while surface water catchment systems in areas impacted by acidic deposition may contain elevated soluble As levels. Acidification of aquatic ecosystems that are drinking water sources may pose the prospect of enhanced release of As from sediment to water as well as reduction in water levels of Se. Acidification of ground waters, where As appears to be especially mobile, is of particular concern in this regard. The potential impact of acidic deposition on As and Se in soils cannot readily be assessed with respect to human exposure, but it would appear that the behavior of these metalloids in poorly buffered, poorly immobilizing soils, e.g., sandy soils of low metal hydrous oxide content, would be most affected. The effect is opposite for the two elements; lowered pH would appear to enhance As mobility and to reduce Se availability. Altered acidity of both soil and aquatic systems poses a risk for altered biotransformation processes involving both As and Se, thereby affecting the relative amounts of different chemical forms varying in their toxicity to humans as well as influencing biogeochemical cycling. PMID:4076075

Potential impact of acid precipitation on arsenic and selenium.

PubMed

Mushak, P

1985-11-01

The potential impact of acidic precipitation on the environmental mobility of the metalloids arsenic (As) and selenium (Se) has not been given much attention and is poorly understood. As with other elements, the interest here is the potential effect of environmental acidification on environmental behavior in ways that are relevant to human exposure to these metalloids. Available information on acid precipitation and the environmental behavior of these metalloids do, however, permit some preliminary conclusions to be drawn. Both As and Se appear to be mobilized from household plumbing into tap water by the corrosive action of soft, mildly acidic water, while surface water catchment systems in areas impacted by acidic deposition may contain elevated soluble As levels. Acidification of aquatic ecosystems that are drinking water sources may pose the prospect of enhanced release of As from sediment to water as well as reduction in water levels of Se. Acidification of ground waters, where As appears to be especially mobile, is of particular concern in this regard. The potential impact of acidic deposition on As and Se in soils cannot readily be assessed with respect to human exposure, but it would appear that the behavior of these metalloids in poorly buffered, poorly immobilizing soils, e.g., sandy soils of low metal hydrous oxide content, would be most affected. The effect is opposite for the two elements; lowered pH would appear to enhance As mobility and to reduce Se availability. Altered acidity of both soil and aquatic systems poses a risk for altered biotransformation processes involving both As and Se, thereby affecting the relative amounts of different chemical forms varying in their toxicity to humans as well as influencing biogeochemical cycling.

GENOTYPE AND PHENOTYPE IN THE METABOLISM, TOXICITY AND CARCINOGENICITY OF ARSENIC

EPA Science Inventory

This research will study the role of genetic factors in the expression of arsenic toxicity. The project will determine whether the interindividual variation in response is related to differences in the capacity to metabolize inorganic arsenic, if these differences in metabolic c...

Extraction and speciation of arsenic in lacustrine sediments

USGS Publications Warehouse

Ficklin, W.H.

1990-01-01

Arsenic was partially extracted with 4.OM hydrochloric acid, from samples collected at 25-cm intervals in a 350-cm column of sediment at Milltown Reservoir, Montana and from a 60-cm core of sediment collected at the Cheyenne River Embayment of Lake Oahe, South Dakota. The sediment in both reservoirs is highly contaminated with arsenic. The extracted arsenic was separated into As(III) and As(V) on acetate form Dowex 1-X8 ion-exchange resin with 0.12M HCl eluent. Residual arsenic was sequentially extracted with KClO3 and HCl. Arsenic was determined by graphite-furnace atomic-absorption spectrometry. The analytical results define oxidized and reduced zones in the sediment columns. ?? 1990.

Poultry Consumption and Arsenic Exposure in the U.S. Population.

PubMed

Nigra, Anne E; Nachman, Keeve E; Love, David C; Grau-Perez, Maria; Navas-Acien, Ana

2017-03-01

Arsenicals (roxarsone and nitarsone) used in poultry production likely increase inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and roxarsone or nitarsone concentrations in poultry meat. However, the association between poultry intake and exposure to these arsenic species, as reflected in elevated urinary arsenic concentrations, is unknown. Our aim was to evaluate the association between 24-hr dietary recall of poultry consumption and arsenic exposure in the U.S. population. We hypothesized first, that poultry intake would be associated with higher urine arsenic concentrations and second, that the association between turkey intake and increased urine arsenic concentrations would be modified by season, reflecting seasonal use of nitarsone. We evaluated 3,329 participants ≥ 6 years old from the 2003-2010 National Health and Nutrition Examination Survey (NHANES) with urine arsenic available and undetectable urine arsenobetaine levels. Geometric mean ratios (GMR) of urine total arsenic and DMA were compared across increasing levels of poultry intake. After adjustment, participants in the highest quartile of poultry consumption had urine total arsenic 1.12 (95% CI: 1.04, 1.22) and DMA 1.13 (95% CI: 1.06, 1.20) times higher than nonconsumers. During the fall/winter, participants in the highest quartile of turkey intake had urine total arsenic and DMA 1.17 (95% CI: 0.99, 1.39; p -trend = 0.02) and 1.13 (95% CI: 0.99, 1.30; p -trend = 0.03) times higher, respectively, than nonconsumers. Consumption of turkey during the past 24 hr was not associated with total arsenic or DMA during the spring/summer. Poultry intake was associated with increased urine total arsenic and DMA in NHANES 2003-2010, reflecting arsenic exposure. Seasonally stratified analyses by poultry type provide strong suggestive evidence that the historical use of arsenic-based poultry drugs contributed to arsenic exposure in the U.S. Nigra AE, Nachman KE, Love DC, Grau

Determination of arsenic species in marine samples by HPLC-ICP-MS.

PubMed

Hirata, Shizuko; Toshimitsu, Hideki; Aihara, Masato

2006-01-01

Arsenic speciation analysis in marine samples was performed using high performance liquid chromatography (HPLC) with ICP-MS detection. The separation of eight arsenic species viz. arsenite (As(III)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenate (As(V)), arsenobetaine, trimethylarsine oxide (TMAO), arsenocholine and tetramethylarsonium ion (TeMAs) was achieved on a Shiseido Capcell Pak C18 column by using an isocratic eluent (pH 3.0), in which condition As(III) and MMA were co-eluted. The entire separation was accomplished in 15 min. The detection limits for 8 arsenic species by HPLC/ICP-MS were in the range of 0.02 - 0.10 microg L(-1) based on 3sigma of blank response (n=9). The precision was calculated to be 3.1-7.3% (RSD) for all eight species. The method then successfully applied to several marine samples e.g., oyster, scallop, fish, and shrimps. For the extraction of arsenic species from seafood products, the low power microwave digestion was employed. The extraction efficiency was in the range of 52.9 - 112.3%. Total arsenic concentrations were analyzed by using the microwave acid digestion. The total arsenics in the certified reference materials (DORM-2 and TORT-2) were analyzed and agreed with the certified values. The concentrations of arsenics in marine samples were in the range 6.6 - 35.1 microg g(-1).

Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation.

PubMed

Flanagan, Sara V; Johnston, Richard B; Zheng, Yan

2012-11-01

A national drinking water quality survey conducted in 2009 furnished data that were used to make an updated estimate of chronic arsenic exposure in Bangladesh. About 20 million and 45 million people were found to be exposed to concentrations above the national standard of 50 µg/L and the World Health Organization's guideline value of 10 µg/L, respectively. From the updated exposure data and all-cause mortality hazard ratios based on local epidemiological studies, it was estimated that arsenic exposures to concentrations > 50 µg/L and 10-50 µg/L account for an annual 24,000 and perhaps as many as 19,000 adult deaths in the country, respectively. Exposure varies widely in the 64 districts; among adults, arsenic-related deaths account for 0-15% of all deaths. An arsenic-related mortality rate of 1 in every 16 adult deaths could represent an economic burden of 13 billion United States dollars (US$) in lost productivity alone over the next 20 years. Arsenic mitigation should follow a two-tiered approach: (i) prioritizing provision of safe water to an estimated 5 million people exposed to > 200 µg/L arsenic, and (ii) building local arsenic testing capacity. The effectiveness of such an approach was demonstrated during the United Nations Children's Fund 2006-2011 country programme, which provided safe water to arsenic-contaminated areas at a cost of US$ 11 per capita. National scale-up of such an approach would cost a few hundred million US dollars but would improve the health and productivity of the population, especially in future generations.

Interaction between arsenic exposure from drinking water and genetic susceptibility in carotid intima-media thickness in Bangladesh

PubMed Central

Wu, Fen; Jasmine, Farzana; Kibriya, Muhammad G.; Liu, Mengling; Cheng, Xin; Parvez, Faruque; Paul-Brutus, Rachelle; Islam, Tariqul; Paul, Rina Rani; Sarwar, Golam; Ahmed, Alauddin; Jiang, Jieying; Islam, Tariqul; Slavkovich, Vesna; Rundek, Tatjana; Demmer, Ryan T.; Desvarieux, Moise; Ahsan, Habibul; Chen, Yu

2014-01-01

Epidemiologic studies that evaluated genetic susceptibility to the effects of arsenic exposure from drinking water on subclinical atherosclerosis are limited. We conducted a cross-sectional study of 1,078 participants randomly selected from the Health Effects of Arsenic Longitudinal Study in Bangladesh to evaluate whether the association between arsenic exposure and carotid artery intima-medial thickness (cIMT) differs by 207 single-nucleotide polymorphisms (SNPs) in 18 genes related to arsenic metabolism, oxidative stress, inflammation, and endothelial dysfunction. Although not statistically significant after correcting for multiple testing, nine SNPs in APOE, AS3MT, PNP, and TNF genes had a nominally statistically significant interaction with well-water arsenic in cIMT. For instance, the joint presence of a higher level of well-water arsenic (≥ 40.4 μg/L) and the GG genotype of AS3MT rs3740392 was associated with a difference of 40.9 μm (95% CI = 14.4, 67.5) in cIMT, much greater than the difference of cIMT associated with the genotype alone (β = -5.1 μm, 95% CI = -31.6, 21.3) or arsenic exposure alone (β = 7.2 μm, 95% CI = -3.1, 17.5). The pattern and magnitude of the interactions were similar when urinary arsenic was used as the exposure variable. Additionally, the at-risk genotypes of the AS3MT SNPs were positively related to proportion of monomethylarsonic acid (MMA) in urine, which is indicative of arsenic methylation capacity. The findings provide novel evidence that genetic variants related to arsenic metabolism may play an important role in arsenic-induced subclinical atherosclerosis. Future replication studies in diverse populations are needed to confirm the findings. PMID:24593923

Interaction between arsenic exposure from drinking water and genetic susceptibility in carotid intima-media thickness in Bangladesh.

PubMed

Wu, Fen; Jasmine, Farzana; Kibriya, Muhammad G; Liu, Mengling; Cheng, Xin; Parvez, Faruque; Paul-Brutus, Rachelle; Paul, Rina Rani; Sarwar, Golam; Ahmed, Alauddin; Jiang, Jieying; Islam, Tariqul; Slavkovich, Vesna; Rundek, Tatjana; Demmer, Ryan T; Desvarieux, Moise; Ahsan, Habibul; Chen, Yu

2014-05-01

Epidemiologic studies that evaluated genetic susceptibility for the effects of arsenic exposure from drinking water on subclinical atherosclerosis are limited. We conducted a cross-sectional study of 1078 participants randomly selected from the Health Effects of Arsenic Longitudinal Study in Bangladesh to evaluate whether the association between arsenic exposure and carotid artery intima-media thickness (cIMT) differs by 207 single-nucleotide polymorphisms (SNPs) in 18 genes related to arsenic metabolism, oxidative stress, inflammation, and endothelial dysfunction. Although not statistically significant after correcting for multiple testing, nine SNPs in APOE, AS3MT, PNP, and TNF genes had a nominally statistically significant interaction with well-water arsenic in cIMT. For instance, the joint presence of a higher level of well-water arsenic (≥ 40.4 μg/L) and the GG genotype of AS3MT rs3740392 was associated with a difference of 40.9 μm (95% CI = 14.4, 67.5) in cIMT, much greater than the difference of cIMT associated with the genotype alone (β = -5.1 μm, 95% CI = -31.6, 21.3) or arsenic exposure alone (β = 7.2 μm, 95% CI = -3.1, 17.5). The pattern and magnitude of the interactions were similar when urinary arsenic was used as the exposure variable. Additionally, the at-risk genotypes of the AS3MT SNPs were positively related to the proportion of monomethylarsonic acid (MMA) in urine, which is indicative of arsenic methylation capacity. The findings provide novel evidence that genetic variants related to arsenic metabolism may play an important role in arsenic-induced subclinical atherosclerosis. Future replication studies in diverse populations are needed to confirm the findings. Copyright © 2014 Elsevier Inc. All rights reserved.

New Sorbents for Removing Arsenic From Water

NASA Astrophysics Data System (ADS)

McConchie, D. M.; Genc-Fuhrman, H.; Clark, M. W.; Caldicott, W.; Davies-McConchie, F. G.

2004-12-01

Elevated concentrations of arsenic in the drinking water used in many countries, including some of the poorest developing countries, and recognition that consuming this water can have serious consequences for human health, have led to increased investigations of ways to obtain safe water supplies. Finding new groundwater resources is a possible solution but this is a costly strategy that has no guarantee of success, particularly in areas where water is already a scarce commodity. The alternative is to treat water that is already available, but existing technologies are usually too expensive, too difficult to operate and maintain, or not completely effective when used in less developed countries or remote areas. There is therefore, an urgent need to find a simple and effective but inexpensive sorbent for arsenic that can be used to treat large volumes of water under less than ideal conditions. In this paper we present the results of field and laboratory trials that used a new, highly cost-effective, sorbent to remove arsenic from contaminated water. BauxsolT is the name given to the cocktail of minerals prepared by treating caustic bauxite refinery residues with Mg and Ca to produce a substance with a reaction pH of about 8.5, a high acid neutralizing capacity and an excellent ability to trap trace metals, metalloids and some other ionic species. The trapped ions are tightly bound by processes that include; precipitation of low solubility neoformational minerals, isomorphous substitution, solid-state diffusion, and adsorption; it is also an excellent flocculant. Although ordinary BauxsolT has an excellent ability to bind arsenate, and to a lesser extent arsenite, this ability can be further increased for particular water types by using activated BauxsolT or BauxsolT combined with small amounts of other reagents. Field trials conducted at the Gilt Edge Mine, South Dakota, showed that the addition of BauxsolT to highly sulfidic waste rock reduced the arsenic

DNA DAMAGE INDUCED BY METHYLATED TRIVALENT ARSENICALS IS MEDIATED BY REACTIVE OXYGEN SPECIES

EPA Science Inventory

Abstract
Arsenic is a human carcinogen; however, the mechanisms of arsenic's induction of carcinogenic effects have not been identified clearly. We have shown previously that monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMAIII ) are genotoxic and can damage supe...

Capacity of Lemna gibba L. (duckweed) for uranium and arsenic phytoremediation in mine tailing waters.

PubMed

Mkandawire, Martin; Taubert, Barbara; Dudel, E Gert

2004-01-01

The potential of Lemna gibba L. to clean uranium and arsenic contamination from mine surface waters was investigated in wetlands of two former uranium mines in eastern Germany and in laboratory hydroponic culture. Water and plants were sampled and L gibba growth and yield were monitored in tailing ponds from the field study sites. Contaminant accumulation, growth and yield experiments were conducted in the laboratory using synthetic tailing water. Mean background concentrations of the surface waters were 186.0+/-81.2 microg l(-1) uranium and 47.0+/-21.3 microg l(-1) arsenic in Site one and 293.7+/-121.3 microg l(-1) uranium and 41.37+/-24.7 microg l(-1) arsenic in Site two. The initial concentration of both uranium and arsenic in the culture solutions was 100 microg l(-1). The plant samples were either not leached, leached with deionized H2O or ethylenediaminetetracetic (EDTA). The results revealed high bioaccumulation coefficients for both uranium and arsenic. Uranium and arsenic content of L gibba dry biomass of the field samples were as follows: nonleached samples > deionized H2O leached (insignificant ANOVA p = 0.05) > EDTA leached. The difference in both arsenic and uranium enrichment were significantly high between the nonleached and the other two lead samples tested at ANOVA p > 0.001. Estimated mean L gibba density in surface water was 85,344.8+/-1843.4 fronds m(-2) (approximately 1319.7 g m(-2)). The maximum specific growth rate was 0.47+/-0.2 d(-1), which exceeded reported specific growth rates for L gibba in the literature. Average yield was estimated at 20.2+/-6.7 g m(-2) d(-1), giving approximately 73.6+/-21.4 t ha(-1) y(-1) as the annual yield. The highest accumulations observed were 896.9+/-203.8 mg kg(-1) uranium and 1021.7+/-250.8 mg kg(-1) arsenic dry biomass for a 21-d test period in the laboratory steady-state experiments. The potential extractions from surface waters with L gibba L. were estimated to be 662.7 kg uranium ha(-1) yr(-1) and 751

DNA DAMAGE INDUCED BY METHYLATED TRIVALENT ARSENICALS IS MEDIATED BY REACTIVE OXYGEN SPECIES

EPA Science Inventory

Abstract

Arsenic is a human carcinogen; however; the mechanisms of arsenic's induction of carcinogenic effects have not been identified clearly. We have shown previously that
monomethylarsonous acid (MMAIII) and dimethylarsinous acid (DMA III) are genotoxic and can d...

Arsenic accumulation in three species of sea turtles.

PubMed

Saeki, K; Sakakibara, H; Sakai, H; Kunito, T; Tanabe, S

2000-09-01

Arsenic in the liver, kidney and muscle of three species of sea turtles, e.g., green turtles (Chelonia mydas), loggerhead turtles (Caretta caretta) and hawksbill turtles (Eretmochelys imbricata), were determined using HG-AAS, followed by arsenic speciation analysis using HPLC-ICP-MS. The order of arsenic concentration in tissues was muscle > kidney > liver. Unexpectedly, the arsenic concentrations in the hawksbill turtles feeding mainly on sponges were higher than the two other turtles primarily eating algae and mollusk which accumulate a large amount of arsenic. Especially, the muscles of the hawksbill turtles contained remarkably high arsenic concentrations averaging 153 mg kg(-1) dry weight with the range of 23.1-205 mg kg(-1) (n = 4), even in comparison with the data from other organisms. The arsenic concentrations in the tissues of the green turtles were significantly decreased with standard carapace length as an indicator of growth. In arsenic compounds, arsenobetaine was mostly detected in the tissues of all the turtles. Besides arsenobetaine, a small amount of dimethylarsinic acid was also observed in the hawksbill turtles.

Strain differences in arsenic-induced oxidative lesion via arsenic biomethylation between C57BL/6J and 129X1/SvJ mice

NASA Astrophysics Data System (ADS)

Wu, Ruirui; Wu, Xiafang; Wang, Huihui; Fang, Xin; Li, Yongfang; Gao, Lanyue; Sun, Guifan; Pi, Jingbo; Xu, Yuanyuan

2017-03-01

Arsenic is a common environmental and occupational toxicant with dramatic species differences in its susceptibility and metabolism. Mouse strain variability may provide a better understanding of the arsenic pathological profile but is largely unknown. Here we investigated oxidative lesion induced by acute arsenic exposure in the two frequently used mouse strains C57BL/6J and 129X1/SvJ in classical gene targeting technique. A dose of 5 mg/kg body weight arsenic led to a significant alteration of blood glutathione towards oxidized redox potential and increased hepatic malondialdehyde content in C57BL/6J mice, but not in 129X1/SvJ mice. Hepatic antioxidant enzymes were induced by arsenic in transcription in both strains and many were higher in C57BL/6J than 129X1/SvJ mice. Arsenic profiles in the liver, blood and urine and transcription of genes encoding enzymes involved in arsenic biomethylation all indicate a higher arsenic methylation capacity, which contributes to a faster hepatic arsenic excretion, in 129X1/SvJ mice than C57BL/6J mice. Taken together, C57BL/6J mice are more susceptible to oxidative hepatic injury compared with 129X1/SvJ mice after acute arsenic exposure, which is closely associated with arsenic methylation pattern of the two strains.

Potential application of SERS for arsenic speciation in biological matrices.

PubMed

Yang, Mingwei; Matulis, Shannon; Boise, Lawrence H; McGoron, Anthony J; Cai, Yong

2017-08-01

Speciation of arsenic is usually carried out using chromatography-based methods coupled with spectroscopic determination; however, the inevitable procedures involving sample preparation and separation could potentially alter the integrity of the arsenic metabolites present in biological samples. Surface-enhanced Raman spectroscopy (SERS) could be a promising alternative for providing a reliable arsenic analysis under the influence of a cellular matrix. A method for arsenic speciation using SERS in cellular matrix was developed in this study and four arsenicals were selected, including arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ) and dimethylarsinic acid (DMA V ). Silver nanoparticles in the form of colliodal suspension with different surface charges, i.e., coated with citrate (AgNPs-Citrate) and spermine (AgNPs-Spermine) were employed as SERS substrates. Adsorption of arsenicals on nanoparticles in colloidal suspensions and the cellular matrix and the pH, size, and zeta potential of the colloidal suspensions were investigated for a better understanding of the SERS signal response of arsenicals in the colloidal suspensions or under the influence of cellular matrix. Arsenicals showed substantially different SERS responses in the two colloidal suspensions, mainly because of the distinct difference in the interaction between the arsenicals and the nanoparticles. Arsenic speciation in cell lysate could be successfully carried out in AgNPs-Spermine suspension, while AgNPs-Citrate could not yield significant SERS signals under the experimental conditions. This study proved that AgNPs-Spermine colloidal suspension could be a promising SERS substrate for studying arsenic metabolism in a biological matrix, reducing the bias caused by traditional techniques that involve sample extraction and pretreatment.

(-)-Epigallocatechin-3-gallate (EGCG) attenuates arsenic-induced cardiotoxicity in rats.

PubMed

Sun, Tao-Li; Liu, Zhi; Qi, Zheng-Jun; Huang, Yong-Pan; Gao, Xiao-Qin; Zhang, Yan-Yan

2016-07-01

Chronic arsenic exposure in drinking water is associated with the abnormalities of cardiac tissue. Excessive generation of ROS induced by arsenic has a central role in arsenic-induced cardiotoxicity. (-)-Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study was aim to evaluate the effect of EGCG on arsenic-induced cardiotoxicity in vivo and in vitro. Treatment with NaAsO2 seriously affected the morphology and ultrastructure of myocardium, and induced cardiac injuries, oxidative stress, intracellular calcium accumulation and apoptosis in rats. In consistent with in vivo study, the injuries, oxidative stress and apoptosis were also observed in NaAsO2-treated H9c2 cells. All of these effects induced by NaAsO2 were attenuated by EGCG. These results suggest EGCG could attenuate NaAsO2-induced cardiotoxicity, and the mechanism may involve its potent antioxidant capacity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Remediation of arsenic in mung bean (Vigna radiata) with growth enhancement by unique arsenic-resistant bacterium Acinetobacter lwoffii.

PubMed

Das, Joyati; Sarkar, Priyabrata

2018-05-15

Arsenic, a carcinogenic and toxic contaminant of soil and water, affects human health adversely. During last few decades, it has been an important global environmental issue. Among several arsenic detoxification methods remediation using arsenic resistant microbes is proved to be environment-friendly and cost-effective. This study aimed to test the effects of arsenic utilizing bacterial strain Acinetobacter lwoffii (RJB-2) on arsenic uptake and growth of mung bean plants (Vigna radiata). RJB-2 exhibited tolerance up to 125mM of arsenic (V) and 50mM of arsenic (III). RJB-2 produced plant growth promoting substances e.g. indole acetic acid (IAA), siderophores, exopolysaccharide (EPS) and phosphate solubilization in the absence and in presence of arsenic. Pot experiments were used to scrutinize the role of RJB-2 on arsenic uptake and growth of mung bean plants grown in soil amended with 22.5mgkg -1 of sodium arsenate (Na 2 HAsO 4 ·7H 2 O). RJB-2 could arrest arsenic uptake in just 7days and increase plant growth, number of plants per pot, chlorophyll and carotenoid content of the mung bean plants. RJB-2 formed biofilm and its root-association helped to abate arsenic uptake in mung bean. Confocal and light microscopic studies also revealed the abatement of arsenic uptake and increase in chlorophyll content in mung bean plants in presence of RJB-2. RJB-2 was also responsible for less production of reactive oxygen species (ROS) in mung bean plants reducing the oxidative damage caused by arsenic. The lower percentage of electrolytic leakage (EL) in RJB-2 inoculated mung bean plants proved arsenic abatement. The study also reported the distribution of arsenic in various parts of mung bean plant. RJB-2 owing to its intrinsic abilities of plant growth promotion even in presence of high concentrations of arsenic could inhibit arsenic uptake completely and therefore it could be used in large-scale cultivation for phytostabilization of plants. Copyright © 2017 Elsevier B

Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation

PubMed Central

Flanagan, Sara V; Johnston, Richard B

2012-01-01

Abstract A national drinking water quality survey conducted in 2009 furnished data that were used to make an updated estimate of chronic arsenic exposure in Bangladesh. About 20 million and 45 million people were found to be exposed to concentrations above the national standard of 50 µg/L and the World Health Organization’s guideline value of 10 µg/L, respectively. From the updated exposure data and all-cause mortality hazard ratios based on local epidemiological studies, it was estimated that arsenic exposures to concentrations > 50 µg/L and 10–50 µg/L account for an annual 24 000 and perhaps as many as 19 000 adult deaths in the country, respectively. Exposure varies widely in the 64 districts; among adults, arsenic-related deaths account for 0–15% of all deaths. An arsenic-related mortality rate of 1 in every 16 adult deaths could represent an economic burden of 13 billion United States dollars (US$) in lost productivity alone over the next 20 years. Arsenic mitigation should follow a two-tiered approach: (i) prioritizing provision of safe water to an estimated 5 million people exposed to > 200 µg/L arsenic, and (ii) building local arsenic testing capacity. The effectiveness of such an approach was demonstrated during the United Nations Children’s Fund 2006–2011 country programme, which provided safe water to arsenic-contaminated areas at a cost of US$ 11 per capita. National scale-up of such an approach would cost a few hundred million US dollars but would improve the health and productivity of the population, especially in future generations. PMID:23226896

Nanostructured Mn-Fe Binary Mixed Oxide: Synthesis, Characterization and Evaluation for Arsenic Removal.

PubMed

Pillewan, Pradnya; Mukherjee, Shrabanti; Bansiwal, Amit; Rayalu, Sadhana

2014-07-01

Adsorption of arsenic on bimetallic Mn and Fe mixed oxide was carried out using both field as well as simulated water. The material was synthesized using hydrothermal method and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Langmuir and Freundlich adsorption isotherms were computed using batch adsorption studies to determine the adsorption capacity of Mn-Fe binary mixed oxide for arsenic. Adsorption capacity for MFBMO obtained from Freundlich model was found to be 2.048 mg/g for simulated water and 1.084 mg/g for field water. Mn-Fe binary mixed oxide was found to be effective adsorbent for removal of arsenic from water.

Arsenic removal by iron oxide coated sponge: treatment and waste management.

PubMed

Nguyen, Tien Vinh; Rahman, Abdur; Vigneswaran, Saravanamuthu; Ngo, Huu Hao; Kandasamy, Jaya; Nguyen, Duc Tho; Do, Tuan Anh; Nguyen, Trung Kien

2009-01-01

One of the problems in drinking water that raises concern over the world is that millions of people still have to use arsenic-contaminated water. There is a worldwide need to develop appropriate technologies to remove arsenic from water for household and community water supply systems. In this study, a new material namely iron oxide coated sponge (IOCSp) was developed and used to remove arsenic (As) from contaminated groundwater in Vietnam. The results indicated that IOCSp has a high capacity in removing both As (V) and As (III). The adsorption capacity of IOCSp was up to 4.6 mg As/g IOCSp, showing better than many other materials. It was observed from a pilot study that a small quantity of IOCSp (180 g) could reduce As concentration of 480 microg/L in 1.5 m3 of contaminated natural water to below 40 microg/L. In addition, an exhausted IOCSp, containing a large amount of arsenic (up to 0.42 wt %) could safely be disposed through the solidification/stabilization with cement. Addition of fly ash also reduced the amount of arsenic in the leachate.

All-Trans Retinoic Acid Ameliorates Arsenic-Induced Oxidative Stress and Apoptosis in the Rat Uterus by Modulating MAPK Signaling Proteins.

PubMed

Chatterjee, Aniruddha; Chatterji, Urmi

2017-11-01

Exposure to arsenic leads to inhibition of the anti-oxidant defense mechanism of the body. Reactive oxygen species generated in response to arsenic causes reproductive failures in exposed females and also acts as an inducer of apoptosis. As a prospective remedial agent, all-trans retinoic acid (ATRA) was assessed for reversing arsenic-induced oxidative stress and apoptosis. Rats exposed to arsenic for 28 days were allowed to recover naturally or were treated simultaneously with ATRA for 28 days or up to 56 days. Production of H 2 O 2 was detected using 2',7'-dichlorfluorescein diacetate (DCFCA) by flow cytometry. Catalase, superoxide dismutase, glutathione, ALT, and AST were estimated by biochemical assays and Western blot analyses. Detection of apoptosis was performed using annexin V-FITC/propidium iodide. Expressions of p53, p21, cleaved caspase 3, JNK/pJNK, and ERK/pERK levels were estimated using Western blot analysis. Elemental arsenic deposition in the rat uterus and liver was estimated by atomic absorption spectrophotometry. Our results confirmed that ATRA ameliorated sodium arsenite-induced ROS generation, restored redox balance, and prevented apoptosis. Concomitant recovery was observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Tissue arsenic deposition was significantly reduced in the uterus upon continuous ATRA treatment. The results revealed that ATRA reversed arsenic-induced free radical generation, activated the anti-oxidant defence system, and subsequently repressed p53-dependent apoptosis through inhibition of the MAPK signaling components. J. Cell. Biochem. 118: 3796-3809, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Iron-impregnated granular activated carbon for arsenic removal from drinking water

NASA Astrophysics Data System (ADS)

Chang, Qigang

A new multi-step iron impregnation method was developed in this study to impregnate GAC with a high amount of iron that possesses desired characteristics: stable, even distribution, and high arsenic adsorption capacity. Research was carried out to investigate the impact of the amount of impregnated iron on arsenic adsorption properties: capacity, affinity, and kinetics. Fe-GACs were characterized in terms of the amount, stability, distribution, morphology, and species of impregnated iron. It was found that a high amount of iron was stably impregnated in GAC. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis demonstrated that the impregnated iron was evenly distributed on the internal surface of GAC. Impregnated iron formed nano-size particles and existed in both crystalline (akaganeite) and amorphous iron. Arsenic adsorption tests were conducted using Fe-GACs with iron content of 1.64--28.90% in a low arsenic concentration that is typical for drinking water treatment. The amount of impregnated iron affects arsenic maximum adsorption capacity (qm) but has little impact on the Langmuir constant h (the affinity of adsorbent for adsorbate). The qm for both As(V) and As(III) adsorptions increased significantly with increase of the amount of impregnated iron up to 13.59%. Further increase of iron amounts caused a gradual decrease of qm for As(V). BET analysis indicated impregnated iron possesses the highest surface area at iron content of 13.59%. A new second-order kinetic model was developed to investigate the impact of the amounts of impregnated iron on arsenic adsorption kinetics. With iron content increased from 1.64% to 28.90%, the intrinsic adsorption rate constants reduced from 4.6x10-2 1/hr to 1.18x10 -3 1/hr, which indicates that impregnated iron slows arsenic intraparticle diffusion rate in Fe-GAC. The decreased arsenic intraparticle diffusion rate was most likely caused by reduced pore size of Fe-GACs. Column tests were

Determinants and Consequences of Arsenic Metabolism Efficiency among 4,794 Individuals: Demographics, Lifestyle, Genetics, and Toxicity.

PubMed

Jansen, Rick J; Argos, Maria; Tong, Lin; Li, Jiabei; Rakibuz-Zaman, Muhammad; Islam, Md Tariqul; Slavkovich, Vesna; Ahmed, Alauddin; Navas-Acien, Ana; Parvez, Faruque; Chen, Yu; Gamble, Mary V; Graziano, Joseph H; Pierce, Brandon L; Ahsan, Habibul

2016-02-01

Exposure to inorganic arsenic (iAs), a class I carcinogen, affects several hundred million people worldwide. Once absorbed, iAs is converted to monomethylated (MMA) and then dimethylated forms (DMA), with methylation facilitating urinary excretion. The abundance of each species in urine relative to their sum (iAs%, MMA%, and DMA%) varies across individuals, reflecting differences in arsenic metabolism capacity. The association of arsenic metabolism phenotypes with participant characteristics and arsenical skin lesions was characterized among 4,794 participants in the Health Effects of Arsenic Longitudinal Study (Araihazar, Bangladesh). Metabolism phenotypes include those obtained from principal component (PC) analysis of arsenic species. Two independent PCs were identified: PC1 appears to represent capacity to produce DMA (second methylation step), and PC2 appears to represent capacity to convert iAs to MMA (first methylation step). PC1 was positively associated (P <0.05) with age, female sex, and BMI, while negatively associated with smoking, arsenic exposure, education, and land ownership. PC2 was positively associated with age and education but negatively associated with female sex and BMI. PC2 was positively associated with skin lesion status, while PC1 was not. 10q24.32/AS3MT region polymorphisms were strongly associated with PC1, but not PC2. Patterns of association for most variables were similar for PC1 and DMA%, and for PC2 and MMA% with the exception of arsenic exposure and SNP associations. Two distinct arsenic metabolism phenotypes show unique associations with age, sex, BMI, 10q24.32 polymorphisms, and skin lesions. This work enhances our understanding of arsenic metabolism kinetics and toxicity risk profiles. ©2015 American Association for Cancer Research.

Poultry Consumption and Arsenic Exposure in the U.S. Population

PubMed Central

Nigra, Anne E.; Nachman, Keeve E.; Love, David C.; Grau-Perez, Maria; Navas-Acien, Ana

2016-01-01

Background: Arsenicals (roxarsone and nitarsone) used in poultry production likely increase inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and roxarsone or nitarsone concentrations in poultry meat. However, the association between poultry intake and exposure to these arsenic species, as reflected in elevated urinary arsenic concentrations, is unknown. Objectives: Our aim was to evaluate the association between 24-hr dietary recall of poultry consumption and arsenic exposure in the U.S. population. We hypothesized first, that poultry intake would be associated with higher urine arsenic concentrations and second, that the association between turkey intake and increased urine arsenic concentrations would be modified by season, reflecting seasonal use of nitarsone. Methods: We evaluated 3,329 participants ≥ 6 years old from the 2003–2010 National Health and Nutrition Examination Survey (NHANES) with urine arsenic available and undetectable urine arsenobetaine levels. Geometric mean ratios (GMR) of urine total arsenic and DMA were compared across increasing levels of poultry intake. Results: After adjustment, participants in the highest quartile of poultry consumption had urine total arsenic 1.12 (95% CI: 1.04, 1.22) and DMA 1.13 (95% CI: 1.06, 1.20) times higher than nonconsumers. During the fall/winter, participants in the highest quartile of turkey intake had urine total arsenic and DMA 1.17 (95% CI: 0.99, 1.39; p-trend = 0.02) and 1.13 (95% CI: 0.99, 1.30; p-trend = 0.03) times higher, respectively, than nonconsumers. Consumption of turkey during the past 24 hr was not associated with total arsenic or DMA during the spring/summer. Conclusions: Poultry intake was associated with increased urine total arsenic and DMA in NHANES 2003–2010, reflecting arsenic exposure. Seasonally stratified analyses by poultry type provide strong suggestive evidence that the historical use of arsenic-based poultry drugs contributed to arsenic

Arsenic-containing fatty acids and hydrocarbons in marine oils - determination using reversed-phase HPLC-ICP-MS and HPLC-qTOF-MS.

PubMed

Sele, Veronika; Sloth, Jens J; Holmelid, Bjarte; Valdersnes, Stig; Skov, Kasper; Amlund, Heidi

2014-04-01

Arsenolipids are the major arsenic species present in marine oils. Several structures of arsenolipids have been elucidated the last 5 years, demonstrating the chemical complexity of this trace element in the marine environment. Several commercial fish oils and marine oils, ranging in total arsenic concentrations from 1.6 to 12.5 mg kg(-1) oil, were analyzed for arsenolipids using reversed-phase high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The arsenolipids were quantified using three different arsenic-containing calibration standards; dimethylarsinate (DMA), triphenylarsinoxide (Ph₃AsO) and a synthesized arsenic-containing hydrocarbon (AsHC) (dimethylarsinoyl nonadecane; C₂₁H₄₃AsO). The observed variation in signal intensity for arsenic during the gradient elution profile in reversed-phase HPLC was compensated for by determining the time-resolved response factors for the arsenolipids. Isotopes of germanium ((74)Ge) and indium ((115)In) were suited as internal standards for arsenic, and were used for verification of the arsenic signal response factors during the gradient elution. Dimethylarsinate was the most suitable calibration standard for the quantification of arsenolipids, with recoveries between 91% and 104% compared to total arsenic measurements in the same extracts. A range of marine oils was investigated, including oils of several fish species, cod liver and seal, as well as three commercial fish oils. The AsHCs - C₁₇H₃₈AsO, C₁₉H₄₂AsO and C₂₃H₃₈AsO - were identified as the major arsenolipids in the extracts of all oils by HPLC coupled with quadrupole time-of-flight mass spectrometry (qTOF-MS). Minor amounts of two arsenic-containing fatty acids (AsFAs) (C₂₃H₃₈AsO₃ and C₂₄H₃₈AsO₃) were also detected in the oils. The sum of the AsHCs and the AsFAs determined in the present study accounted for 17-42% of the total arsenic in the oils

Biological and behavioral factors modify urinary arsenic metabolic profiles in a U.S. population.

PubMed

Hudgens, Edward E; Drobna, Zuzana; He, Bin; Le, X C; Styblo, Miroslav; Rogers, John; Thomas, David J

2016-05-26

Because some adverse health effects associated with chronic arsenic exposure may be mediated by methylated arsenicals, interindividual variation in capacity to convert inorganic arsenic into mono- and di-methylated metabolites may be an important determinant of risk associated with exposure to this metalloid. Hence, identifying biological and behavioral factors that modify an individual's capacity to methylate inorganic arsenic could provide insights into critical dose-response relations underlying adverse health effects. A total of 904 older adults (≥45 years old) in Churchill County, Nevada, who chronically used home tap water supplies containing up to 1850 μg of arsenic per liter provided urine and toenail samples for determination of total and speciated arsenic levels. Effects of biological factors (gender, age, body mass index) and behavioral factors (smoking, recent fish or shellfish consumption) on patterns of arsenicals in urine were evaluated with bivariate analyses and multivariate regression models. Relative contributions of inorganic, mono-, and di-methylated arsenic to total speciated arsenic in urine were unchanged over the range of concentrations of arsenic in home tap water supplies used by study participants. Gender predicted both absolute and relative amounts of arsenicals in urine. Age predicted levels of inorganic arsenic in urine and body mass index predicted relative levels of mono- and di-methylated arsenic in urine. Smoking predicted both absolute and relative levels of arsenicals in urine. Multivariate regression models were developed for both absolute and relative levels of arsenicals in urine. Concentration of arsenic in home tap water and estimated water consumption were strongly predictive of levels of arsenicals in urine as were smoking, body mass index, and gender. Relative contributions of arsenicals to urinary arsenic were not consistently predicted by concentrations of arsenic in drinking water supplies but were more

[Effect of glutathione and sodium selenite on the metabolism of arsenic in mice exposed to arsenic through drinking water].

PubMed

Yu, Xiao-Yun; Zhong, Yuan; Niu, Yu-Hong; Qu, Chun-Qing; Li, Ge-Xin; Lü, Xiu-Qiang; Sun, Gui-Fan; Jin, Ya-Ping

2008-09-01

To explore the effect of glutathione (GSH) and sodium selenite on the metabolism of arsenic in the liver, kidney and blood of mice exposed to iAsIII through drinking water. The mice were randomly divided into control, arsenic, GSH and sodium selenite group, respectively. And each group had eight mice and the mice were exposed to 50 mg/L arsenite by drinking water for 4 weeks. Mice were intraperitoneally injected with GSH (600 mg/kg) and sodium selenite (1 mg/kg) for seven days from the beginning of the fourth week. At the end of the fourth week, liver, kidney and blood were sampled to assess the concentrations of inorganic arsenic (iAs), monomethylarsenic acid (MMA), dimethylarsenic acid (DMA) by hydride generation trapping by ultra-hypothermia coupled with atomic absorption spectrometry. The liver DMA (233.76 +/- 60.63 ng/g) concentration in GSH group was significantly higher than the arsenic group (218.36 +/- 42.71 ng/g). The concentration of DMA (88.52 +/- 30.86 ng/g) and total arsenic (TAs) (162.32 +/- 49.45 ng/g) in blood of GSH group was significantly higher than those [(45.32 +/- 12.19 ng/g), (108.51 +/- 18.00 ng/g), respectively] of arsenic groups(q values were 3.06, 6.40, 10.72 respectively, P < 0.05). The primary methylated index (PMI) (0.65 +/- 0.050) and secondary methylated index (SMI) (0.55 +/- 0.050) in liver sample of GSH group were significantly higher than those (0.58 +/- 0.056, 0.44 +/- 0. 093) in arsenic group. In blood samples, the PMI (0.85 +/- 0.066) in GSH group was significantly higher than that (0.54 +/- 0.113) in arsenic group (q values were 3.75, 5.26, 4.21 respectively, P < 0.05). However, no significant difference was identified between sodium selenite and arsenic groups in liver, kidney or blood samples. And no significant difference was detected in kidney samples among all arsenic exposing groups. Exogenous GSH could promote the methylated metabolism of iAsIII, but sodium selenite showed no significant effects.

Implementation of the Arsenic Biosand Filter in Nepal

NASA Astrophysics Data System (ADS)

Murcott, S.; Ngai, T.; Shrestha, R.; Pokharel, K.; Walewijk, S.

2004-05-01

A low-cost, household-scale drinking water filter, the Arsenic Biosand Filter (ABF), appropriate for rural Nepal, was developed by researchers at Massachusetts Institute of Technology and two local partners (ENPHO and RWSSSP) to simultaneously remove arsenic and pathogens from tubewell water. The project implementation site is the Terai region of southern Nepal, where about 90% of people receive water from tubewells and where about 25+% and 40+% of tubewells are contaminated with arsenic (naturally-occurring) and coliforms (from human and animal sources) respectively, causing severe health consequences such as cancers and gastrointestinal illnesses. Despite growing recognition of the immediacy of the arsenic crisis in this region, many previous arsenic technology projects have failed. This is because many of the available technologies have serious drawbacks, including complex production methods, high maintenance, high costs, insufficient filtration rate, and/or reliance on materials unavailable in remote villages. In addition, most technologies treat arsenic and pathogens independently, resulting in complicated treatment operations. Implementation deficiencies including ineffective technology transfer, confusing NGO responsibilities, organizational non-sustainability, lack of user education and contribution, and inadequate long-term maintenance and monitoring capacity are other major problems. The ABF design is optimized based on the socio-economic conditions of rural Terai and is constructed using locally available labor and materials. It was the only arsenic remediation technology to win the prestigious World Bank Development Marketplace Competition in 2003. Funding from this prize will provide start-up capital to pilot a technology transfer network. In 2004, the team has established an in-country technology dissemination and implementation center and is building local capacity in arsenic-affected villages towards long-term, self-reliant, user-participatory safe

Aquatic Humic Substances: Relationship Between Origin and Complexing Capacity.

PubMed

González-Guadarrama, María de Jesús; Armienta-Hernández, Ma Aurora; Rosa, André H

2018-05-01

Aiming to determine the relationship between source and complexing capacity, humic substances obtained from three sites (Sorocaba and Itapanhau Brasilian rivers, and Xochimilco Lake in Mexico) were studied. Copper, manganese, zinc and arsenic complexing capacity were determined for the three substances under various pH conditions. Results showed similar complexing capacity for the three elements depending on the chemistry of each one and on the physico-chemical conditions. Speciation diagrams showed that these conditions affect both, the humic substances, and the transition metals and arsenic.

Lead isotopic compositions of common arsenical pesticides used in New England

USGS Publications Warehouse

Ayuso, Robert; Foley, Nora; Robinson, Gilpin; Wandless, Gregory; Dillingham, Jeremy

2004-01-01

The three most important arsenical pesticides and herbicides that were extensively used on apple, blueberry, and potato crops in New England from mid-1800s to recent times are lead arsenate, calcium arsenate, and sodium arsenate. Lead arsenate was probably the most heavily used of the arsenical pesticides until it was banned in 1988. Other metal-arsenic pesticides were also used but in lesser amounts. A recent report identified areas in New England where arsenical pesticides were used extensively (Robinson and Ayuso, 2004). On the basis of factor analysis of metal concentrations in stream sediment samples, a positive correlation with pesticide use was shown in regions having stream sediment sample populations that contained concentrations of high arsenic and lead. Lead isotope compositions of stream sediments from areas with heavy use of the pesticides could not be entirely explained by lead originating from rock sulfides and their weathering products. An industrial lead contribution (mostly from atmospheric deposition of lead) was suggested in general to explain the lead isotopic distributions of the stream sediments that could not be accounted for by the natural lead in the environment. We concluded that when agricultural land previously contaminated with arsenical pesticides is urbanized, pesticide residues in the soils and stream sediments could be released into the groundwater. No lead isotopic data characterizing the compositions of pesticides were available for comparison. We have determined the lead isotopic compositions of commonly used pesticides in New England, such as lead arsenate, sodium metaarsenite, and calcium arsenate, in order to assist in future isotopic comparisons and to better establish anthropogenic sources of Pb and As. New data are also presented for copper acetoarsenite (or Paris green), methyl arsonic acid and methane arsonic acid, as well as for arsanilic acid, all of which are used as feed additives to promote swine and poultry growth

Separation of arsenic(III) and arsenic(V) in ground waters by ion-exchange

USGS Publications Warehouse

Ficklin, W.H.

1983-01-01

The predominant species of arsenic in ground water are probably arsenite and arsenate. These can be separated with a strong anion-exchange resin (Dowex 1 ?? 8; 100-200 mesh, acetate form) in a 10 cm ?? 7 mm column. Samples are filtered and acidified with concentrated hydrochloric acid (1 ml per 100 ml of sample) at the sample site. Five ml of the acidified sample are used for the separation. At this acidity, As(III) passes through the acetate-form resin, and As(V) is retained. As(V) is eluted by passage of 0.12M hydrochloric acid through the column (resulting in conversion of the resin back into the chloride form). Samples are collected in 5-ml portions up to a total of 20 ml. The arsenic concentration in each portion is determined by graphite-furnace atomic-absorption spectrophotometry. The first two fractions give the As(III) concentration and the last two the As(V) concentration. The detection limit for the concentration of each species is 1 ??g l. ?? 1983.

In Vitro Binding Capacity of Bile Acids by Defatted Corn Protein Hydrolysate

PubMed Central

Kongo-Dia-Moukala, Jauricque Ursulla; Zhang, Hui; Irakoze, Pierre Claver

2011-01-01

Defatted corn protein was digested using five different proteases, Alcalase, Trypsin, Neutrase, Protamex and Flavourzyme, in order to produce bile acid binding peptides. Bile acid binding capacity was analyzed in vitro using peptides from different proteases of defatted corn hydrolysate. Some crystalline bile acids like sodium glycocholate, sodium cholate and sodium deoxycholate were individually tested using HPLC to see which enzymes can release more peptides with high bile acid binding capacity. Peptides from Flavourzyme defatted corn hydrolysate exhibited significantly (p < 0.05) stronger bile acid binding capacity than all others hydrolysates tested and all crystalline bile acids tested were highly bound by cholestyramine, a positive control well known as a cholesterol-reducing agent. The bile acid binding capacity of Flavourzyme hydrolysate was almost preserved after gastrointestinal proteases digestion. The molecular weight of Flavourzyme hydrolysate was determined and most of the peptides were found between 500–180 Da. The results showed that Flavourzyme hydrolysate may be used as a potential cholesterol-reducing agent. PMID:21541043

Arsenic scavenging by aluminum-substituted ferrihydrites in a circumneutral pH river impacted by acid mine drainage.

PubMed

Adra, Areej; Morin, Guillaume; Ona-Nguema, Georges; Menguy, Nicolas; Maillot, Fabien; Casiot, Corinne; Bruneel, Odile; Lebrun, Sophie; Juillot, Farid; Brest, Jessica

2013-11-19

Ferrihydrite (Fh) is a nanocrystalline ferric oxyhydroxide involved in the retention of pollutants in natural systems and in water-treatment processes. The status and properties of major chemical impurities in natural Fh is however still scarcely documented. Here we investigated the structure of aluminum-rich Fh, and their role in arsenic scavenging in river-bed sediments from a circumneutral river (pH 6-7) impacted by an arsenic-rich acid mine drainage (AMD). Extended X-ray absorption fine structure (EXAFS) spectroscopy at the Fe K-edge shows that Fh is the predominant mineral phase forming after neutralization of the AMD, in association with minor amount of schwertmannite transported from the AMD. TEM-EDXS elemental mapping and SEM-EDXS analyses combined with EXAFS analysis indicates that Al(3+) substitutes for Fe(3+) ions into the Fh structure in the natural sediment samples, with local aluminum concentration within the 25-30 ± 10 mol %Al range. Synthetic aluminous Fh prepared in the present study are found to be less Al-substituted (14-20 ± 5 mol %Al). Finally, EXAFS analysis at the arsenic K-edge indicates that As(V) form similar inner-sphere surface complexes on the natural and synthetic Al-substituted Fh studied. Our results provide direct evidence for the scavenging of arsenic by natural Al-Fh, which emphasize the possible implication of such material for scavenging pollutants in natural or engineered systems.

Determination of total arsenic and arsenic(III) in phosphate fertilizers by hydride generation atomic absorption spectrometry after ultrasound-assisted extraction based on a control acid media.

PubMed

Rezende, Helen Cristine; Coelho, Nivia Maria Melo

2014-01-01

An ultrasound-assisted extraction procedure was developed for determination of inorganic arsenic (As) in phosphate fertilizer by hydride generation atomic absorption spectrometry. The variables that affect the hydride generation step were optimized, including the reducer, acid, sample flow rate, and concentrations of the acid and reducer. The determination of As(lll) was performed through the simple control of solution pH with a 0.5 M citric acid-sodium citrate buffer solution at pH 4.5, and total As was determined after a pre-reduction reaction with 1.0% (w/v) thiourea. Ultrasound-assisted acid extraction was performed, and the parameters sonication time and acid and Triton X-114 concentrations were optimized using a 23 factorial design and central composite design. LODs for As(lll) and total As were 0.029 and 0.022 microg/L, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successfully applied in the determination of inorganic As in phosphate fertilizer samples.

Speciation of arsenic in biological samples.

PubMed

Mandal, Badal Kumar; Ogra, Yasumitsu; Anzai, Kazunori; Suzuki, Kazuo T

2004-08-01

Speciation of arsenicals in biological samples is an essential tool to gain insight into its distribution in tissues and its species-specific toxicity to target organs. Biological samples (urine, hair, fingernail) examined in the present study were collected from 41 people of West Bengal, India, who were drinking arsenic (As)-contaminated water, whereas 25 blood and urine samples were collected from a population who stopped drinking As contaminated water 2 years before the blood collection. Speciation of arsenicals in urine, water-methanol extract of freeze-dried red blood cells (RBCs), trichloroacetic acid treated plasma, and water extract of hair and fingernail was carried out by high-performance liquid chromatography (HPLC)-inductively coupled argon plasma mass spectrometry (ICP MS). Urine contained arsenobetaine (AsB, 1.0%), arsenite (iAs(III), 11.3), arsenate (iAs(V), 10.1), monomethylarsonous acid (MMA(III), 6.6), monomethylarsonic acid (MMA(V), 10.5), dimethylarsinous acid (DMA(III), 13.0), and dimethylarsinic acid (DMA(V), 47.5); fingernail contained iAs(III) (62.4%), iAs(V) (20.2), MMA(V) (5.7), DMA(III) (8.9), and DMA(V) (2.8); hair contained iAs(III) (58.9%), iAs(V) (34.8), MMA(V) (2.9), and DMA(V) (3.4); RBCs contained AsB (22.5%) and DMA(V) (77.5); and blood plasma contained AsB (16.7%), iAs(III) (21.1), MMA(V) (27.1), and DMA(V) (35.1). MMA(III), DMA(III), and iAs(V) were not found in any plasma and RBCs samples, but urine contained all of them. Arsenic in urine, fingernails, and hair are positively correlated with water As, suggesting that any of these measurements could be considered as a biomarker to As exposure. Status of urine and exogenous contamination of hair urgently need speciation of As in these samples, but speciation of As in nail is related to its total As (tAs) concentration. Therefore, total As concentrations of nails could be considered as biomarker to As exposure in the endemic areas.

Determination of arsenic species in solid matrices utilizing supercritical fluid extraction coupled with gas chromatography after derivatization with thioglycolic acid n-butyl ester.

PubMed

Wang, Zhifeng; Cui, Zhaojie

2016-12-01

A method using derivatization and supercritical fluid extraction coupled with gas chromatography was developed for the analysis of dimethylarsinate, monomethylarsonate and inorganic arsenic simultaneously in solid matrices. Thioglycolic acid n-butyl ester was used as a novel derivatizing reagent. A systematic discussion was made to investigate the effects of pressure, temperature, flow rate of the supercritical CO 2 , extraction time, concentration of the modifier, and microemulsion on extraction efficiency. The application for real environmental samples was also studied. Results showed that thioglycolic acid n-butyl ester was an effective derivatizing reagent that could be applied for arsenic speciation. Using methanol as modifier of the supercritical CO 2 can raise the extraction efficiency, which can be further enhanced by adding a microemulsion that contains Triton X-405. The optimum extraction conditions were: 25 MPa, 90°C, static extraction for 10 min, dynamic extraction for 25 min with a flow rate of 2.0 mL/min of supercritical CO 2 modified by 5% v/v methanol and microemulsion. The detection limits of dimethylarsinate, monomethylarsonate, and inorganic arsenic in solid matrices were 0.12, 0.26, and 1.1 mg/kg, respectively. The optimized method was sensitive, convenient, and reliable for the extraction and analysis of different arsenic species in solid samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Arsenic remediation from drinking water by synthesized nano-alumina dispersed in chitosan-grafted polyacrylamide.

PubMed

Saha, Suparna; Sarkar, Priyabrata

2012-08-15

An arsenic adsorbent comprising alumina nanoparticles dispersed in polymer matrix was developed and its removal potential studied. Alumina nanoparticles were prepared by reverse microemulsion technique and these were immobilized on chitosan grafted polyacrylamide matrix by in situ dispersion. The loading capacity of this new synthesized adsorbent was found to be high (6.56 mg/g). Batch adsorption studies were performed as a function of contact time, initial arsenic concentration, pH and presence of competing anions. The removal was found to be pH dependent, and maximum removal was obtained at pH 7.2 while the equilibrium time was 6h. The equilibrium adsorption data fitted very well with Freundlich isotherm. However, the D-R isotherm studies indicated that chemisorptions might play an important role. This was also confirmed by the FTIR study of the arsenic loaded adsorbent. A mechanism of arsenic sorption by the new polymeric adsorbent has been proposed. The regeneration study of the adsorbent resulted in retention of 94% capacity in the fifth cycle. An optimum pH of 7.2, operation at normal temperature, high adsorption capacity and good recycle potential of this new adsorbent would make it an ideal material for removal of arsenic from drinking water. Copyright © 2012 Elsevier B.V. All rights reserved.

Neuroprotective effect of curcumin in arsenic-induced neurotoxicity in rats.

PubMed

Yadav, Rajesh S; Shukla, Rajendra K; Sankhwar, Madhu Lata; Patel, Devendra K; Ansari, Reyaz W; Pant, Aditya B; Islam, Fakhrul; Khanna, Vinay K

2010-09-01

Our recent studies have shown that arsenic-induced neurobehavioral toxicity is protected by curcumin by modulating oxidative stress and dopaminergic functions in rats. In addition, the neuroprotective effect of curcumin has been investigated on arsenic-induced alterations in biogenic amines, their metabolites and nitric oxide (NO), which play an important role in neurotransmission process. Decrease in the levels of dopamine (DA, 28%), norepinephrine (NE, 54%), epinephrine (EPN, 46%), serotonin (5-HT, 44%), 3,4-dihydroxyphenylacetic acid (DOPAC, 20%) and homovanillic acid (HVA, 31%) in corpus striatum; DA (51%), NE (22%), EPN (47%), 5-HT (25%), DOPAC (34%) and HVA (41%) in frontal cortex and DA (35%), NE (35%), EPN (29%), 5-HT (54%), DOPAC (37%) and HVA (46%) in hippocampus, observed in arsenic (sodium arsenite, 20 mg/kg body weight, p.o., 28 days) treated rats exhibited a trend of recovery in rats simultaneously treated with arsenic and curcumin (100 mg/kg body weight, p.o., 28 days). Increased levels of NO in corpus striatum (2.4-fold), frontal cortex (6.1-fold) and hippocampus (6.2-fold) in arsenic-treated rats were found decreased in rats simultaneously treated with arsenic and curcumin. It is evident that curcumin modulates levels of brain biogenic amines and NO in arsenic-exposed rats and these results further strengthen its neuroprotective efficacy. Copyright © 2010 Elsevier Inc. All rights reserved.

Arsenic in garden soils and vegetable crops in Cornwall, England: Implications for human health.

PubMed

Xu, J; Thornton, I

1985-12-01

Total concentrations of arsenic in surface (0-15cm) garden soils in the historical mining area of Hayle-Camborne-Godolphin, Cornwall, England are large and range widely (144-892 μg/g). Amounts of water soluble and acid-fluoride extractable soil arsenic are significantly correlated with total content.Examination of 6 salad and vegetable crops grown in 32 gardens has shown arsenic concentrations in the edible tissues to be only slightly elevated. There were strong correlations between arsenic in beetroot, lettuce, onion and peas and soil arsenic (total, water soluble and acid extractable). Regression equations have been calculated. Ridge regression analysis applied to test the importance of other soil variables has shown both iron and phosphorus to influence the uptake of arsenic.Arsenic in all the vegetables sampled was below the statutory limit in the U.K. of 1 mg/kg fresh weight. Implications for health should be assessed in relation to other exposure routesvia water, air and directly ingested dust and soil.

Effect of Oxalic Acid Treatment on Sediment Arsenic Concentrations and Lability under Reducing Conditions

PubMed Central

Sun, Jing; Bostick, Benjamin C.; Mailloux, Brian J.; Ross, James M.; Chillrud, Steven N.

2016-01-01

Oxalic acid enhances arsenic (As) mobilization by dissolving As host minerals and competing for sorption sites. Oxalic acid amendments thus could potentially improve the efficiency of widely used pump-and-treat (P&T) remediation. This study investigates the effectiveness of oxalic acid on As mobilization from contaminated sediments with different As input sources and redox conditions, and examines whether residual sediment As after oxalic acid treatment can still be reductively mobilized. Batch extraction, column, and microcosm experiments were performed in the laboratory using sediments from the Dover Municipal Landfill and the Vineland Chemical Company Superfund sites. Oxalic acid mobilized As from both Dover and Vineland sediments, although the efficiency rates were different. The residual As in both Dover and Vineland sediments after oxalic acid treatment was less vulnerable to microbial reduction than before the treatment. Oxalic acid could thus improve the efficiency of P&T. X-ray absorption spectroscopy analysis indicated that the Vineland sediment samples still contained reactive Fe(III) minerals after oxalic acid treatment, and thus released more As into solution under reducing conditions than the Dover samples. Therefore, the efficacy of P&T must consider sediment Fe mineralogy when evaluating its overall potential for remediating groundwater As. PMID:26970042

Inductively coupled plasma mass spectrometry study of the retention behavior of arsenic species on various solid phase extraction cartridges and its application in arsenic speciation

NASA Astrophysics Data System (ADS)

Yu, Chunhai; Cai, Qiantao; Guo, Zhong-Xian; Yang, Zhaoguang; Khoo, Soo Beng

2003-07-01

Inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the retention behavior of arsenite, arsenate, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), arsenocholine (AsC), trimethylarsine oxide (TMAO) and tetramethylarsonium ion (TMAI) on various silica-based solid phase extraction (SPE) cartridges. A method for arsenic speciation is then developed on the basis of selective SPE separation of arsenic species and highly sensitive ICP-MS detection. Factors affecting the retention and elution of arsenic species were examined. Results showed that the retention of arsenic species depended on the chemical characteristics of arsenic species and the types of sorbent materials. Change of pH in the range of 2.0-9.0 did not show significant effects on the retention of DMA, AsB, AsC, TMAI and TMAO on an ethylbenzene sulfonic acid-based strong cation exchange (SCX-3) cartridge. pH also did not influence the retention of AsB, AsC, TMAI and TMAO on a mixed-mode (M-M) cartridge containing non-polar, strong cation exchange and strong anion exchange (SAX) functional groups. However, the retentions of As(V) and MMA on the SAX and the M-M cartridge changed with pH. As(V) and MMA were completely retained on the SAX cartridge and sequentially selectively eluted with 1.0 mol l -1 acetic acid (for MMA). DMA, AsB, AsC, TMAI and TMAO were completely retained on the SCX-3 cartridge and sequentially selectively eluted with 1.0 mol l -1 HNO 3 (for DMA). As(V), MMA, AsB, AsC, TMAI and TMAO were completely retained on the M-M cartridge. As(III) was not retained on either cartridge and remained in solution. Arsenic species in solution and those eluted from the cartridges were subsequently determined by ICP-MS. A detection limit of 8 ng l -1 arsenic in water sample was obtained. This method was successfully applied to arsenic speciation in various sources of water samples (drinking water, waste water, raw water, etc.) and US National Institute of

Land-use impact on selected forms of arsenic and phosphorus in soils of different functions

NASA Astrophysics Data System (ADS)

Plak, Andrzej; Bartmiński, Piotr; Dębicki, Ryszard

2017-10-01

The aim of the study was to assess the impact of technosols and geomechanically unchanged soils of the Lublin agglomeration on the concentrations of arsenic and phosphorus, and on selected forms of these elements. Arsenic and phosphorus concentrations were determined in the urban soils of Lublin (Poland), and the relationship between their degree of contamination and different types of land use was estimated. The samples collected were subjected to sequential analysis, using ammonium sulphate, acid ammonium phosphate, oxalate buffer (also with ascorbic acid) and aqua regia for arsenic, and ammonium chloride, sodium hydroxide, hydrochloric acid and aqua regia for phosphorus. The influence of the land use forms was observed in the study. The greatest amount of arsenic (19.62 mg kg-1) was found in the industrial soils of Lublin, while the greatest amount of phosphorus (580.4 mg kg-1) was observed in non-anthropogenic soils (mainly due to the natural accumulation processes of this element). Fractions of arsenic and phosphorus obtained during analysis showed strong differentiation. Amorphic and crystalline fractions of arsenic, bound with iron oxides, proved to have the highest share in the total arsenic pool. The same situation was noted for phosphorus.

[Determination of five arsenic species in rice by liquid chromatography-inductively coupled plasma-mass spectrometry].

PubMed

Gong, Jiadi; Cao, Xiaolin; Cao, Zhaoyun; Bian, Yingfang; Yu, Shasha; Chen, Mingxue

2014-07-01

A method was developed for the simultaneous determination of arsenic acid [As (V)], arsenious acid [As (III)], arsenobetaine (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in rice by liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). The extraction reagent was 0.3 mol/L nitric acid with heat-assistant condition for 1.5 h at 95 degrees C. Then, the five arsenic species were separated by an anion exchange column (Dionex IonPac AS19, 250 mm x 4 mm) and detected by ICP-MS. Four kinds of extracted solutions were compared through the extraction efficiency. The concentration of nitric acid, the temperature and the extraction time were optimized. The recoveries of the five arsenic species spiked in rice at two levels ranged from 89.6% to 99.5% with the relative standard deviations (RSDs, n = 5) of 0.6% - 3.6%. The measured values of the arsenic species in standard rice materials were consistent with their standard values. The linear ranges were 0.05 - 200 microg/L for AsB and DMA, 0.10-400 microg/L for As (III) and MMA, 0.15-600 microg/L for As (V). The limits of detection for the five arsenic species were 0.15-0.45 microg/kg. The results showed that the method is much more precise for the risk assessment of the rice. This method is simple, accurate and durable for the determination of arsenic species in rice.

The relationships between arsenic methylation and both skin lesions and hypertension caused by chronic exposure to arsenic in drinking water.

PubMed

Wei, Binggan; Yu, Jiangping; Wang, Jing; Yang, Linsheng; Li, Hairong; Kong, Chang; Xia, Yajuan; Wu, Kegong

2017-07-01

The associations between arsenic exposure, arsenic methylation, and the prevalence of skin lesions and hypertension are investigated. The results indicate that the HS (hypertension and skin lesions) group and the S (skin lesions) group have higher urinary concentrations of iAs (inorganic arsenic), MMA (monomethylarsonic acid), DMA (dimethylarsinous acid) and%MMA, and lower SMI (secondary arsenic methylation index) compared to the H (hypertension) and N (without both hypertension and skin lesions) groups. The arsenic content in water which caused H may be lower than that which caused HS and S. In addition, the odds ratios suggest that higher urinary concentrations of iAs and MMA, %iAs, %MMA and PMI elevate the prevalence of only hypertension and skin lesions, and both hypertension and skin lesions. However, higher%DMA and SMI, and lower%MMA increase the prevalence of both hypertension and skin lesions compared to that of only skin lesions. It can be concluded that skin lesions subjects have higher prevalence of hypertension. Hypertension subjects may have higher prevalence of skin lesions. Lower%DMA and SMI, higher%iAs, %MMA and PMI enhance the prevalence of only hypertension and skin lesions, and both hypertension and skin lesions. Moreover, iAs and MMA may have higher toxicity and lead to both hypertension and skin lesions than to only hypertension. Copyright © 2017 Elsevier B.V. All rights reserved.

Adsorption of phthalic acid and salicylic acid and their effect on exchangeable Al capacity of variable-charge soils.

PubMed

Li, Jiuyu; Xu, Renkou

2007-02-01

Low-molecular-weight (LMW) organic acids may be adsorbed by soils and the adsorption could affect their biodegradation and efficiency in many soil processes. In the present study, the adsorption of phthalic acid and salicylic acid and their effect on the exchangeable Al capacity of variable-charge soils were investigated. The results indicated that phthalic acid and salicylic acid were adsorbed by four variable-charge soils to some extent, oxisols showed a greater adsorption capacity for organic acids than ultisols, and the ability of the four variable-charge soils to adsorb the organic acids at different pH generally followed the order Kunming oxisol > Xuwen oxisol > Jinxian ultisol > Lechang ultisol, which was closely related to their content of free iron oxides and amorphous iron and aluminum oxides. The adsorption of organic acids induced a decrease in the zeta potentials of soils and oxides. Goethite has greater adsorption capacity for organic acid than Xuwen oxisol and the adsorption of organic acids resulted in a bigger decrease in the zeta potential of goethite suspensions. After free iron oxides were removed, less organic acid was adsorbed by Xuwen oxisol and no change was observed in zeta potential for the soil suspension after organic acid was added. The presence of phthalic acid increased the capacity of exchangeable Al and the increment in the four variable-charge soils also followed the order Kunming oxisol > Xuwen oxisol > Lechang ultisol and Jinxian ultisol. The presence of salicylic acid increased the capacity of exchangeable Al in Kunming oxisol, Xuwen oxisol, and Jinxian ultisol, but decreased it in Lechang ultisol due to less adsorption of the acid and formation of soluble Al-salicylate complexes in solution. After free iron oxides were removed, less effect of organic acid on exchangeable Al was observed for Xuwen oxisol, which further confirmed that the iron oxides played a significant role in organic acid adsorption and had a consequent effect

Arsenic-induced dyslipidemia in male albino rats: comparison between trivalent and pentavalent inorganic arsenic in drinking water.

PubMed

Afolabi, Olusegun K; Wusu, Adedoja D; Ogunrinola, Olabisi O; Abam, Esther O; Babayemi, David O; Dosumu, Oluwatosin A; Onunkwor, Okechukwu B; Balogun, Elizabeth A; Odukoya, Olusegun O; Ademuyiwa, Oladipo

2015-06-05

Recent epidemiological evidences indicate close association between inorganic arsenic exposure via drinking water and cardiovascular diseases. However, the exact mechanism of this arsenic-mediated increase in cardiovascular risk factors remains enigmatic. In order to investigate the effects of inorganic arsenic exposure on lipid metabolism, male albino rats were exposed to 50, 100 and 150 ppm arsenic as sodium arsenite and 100, 150 and 200 ppm arsenic as sodium arsenate respectively in their drinking water for 12 weeks. Dyslipidemia induced by the two arsenicals exhibited different patterns. Hypocholesterolemia characterised the effect of arsenite at all the doses, but arsenate induced hypercholesterolemia at the 150 ppm As dose. Hypertriglyceridemia was the hallmark of arsenate effect whereas plasma free fatty acids (FFAs) was increased by the two arsenicals. Reverse cholesterol transport was inhibited by the two arsenicals as evidenced by decreased HDL cholesterol concentrations whereas hepatic cholesterol was increased by arsenite (100 ppm As), but decreased by arsenite (150 ppm As) and arsenate (100 ppm As) respectively. Brain cholesterol and triglyceride were decreased by the two arsenicals; arsenate decreased the renal content of cholesterol, but increased renal content of triglyceride. Arsenite, on the other hand, increased the renal contents of the two lipids. The two arsenicals induced phospholipidosis in the spleen. Arsenite (150 ppm As) and arsenate (100 ppm As) inhibited hepatic HMG CoA reductase. At other doses of the two arsenicals, hepatic activity of the enzyme was up-regulated. The two arsenicals however up-regulated the activity of the brain enzyme. We observed positive associations between tissue arsenic levels and plasma FFA and negative associations between tissue arsenic levels and HDL cholesterol. Our findings indicate that even though sub-chronic exposure to arsenite and arsenate through drinking water produced different patterns of

IRON PRECIPITATION AND ARSENIC ATTENUATION - ASSESSMENT OF ARSENIC NATURAL ATTENUATION OF THE SUBSURFACE USING A GEOCHEMICAL MODEL (PHREEQC)

EPA Science Inventory

Laboratory experiments show that amorphous and poorly crystallized ferric iron hydroxides have much greater capacity to attenuate arsenic compared to clays and other aluminosilicate minerals. Studies (e.g., Lin and Qvarfort, 1996) showed that a sudden change in geochemical condit...

[Effects of α-lipoic acid and vitamin C on oxidative stress in rat exposed to chronic arsenic toxicity].

PubMed

Liu, Chong-Bin; Feng, Yan-Hong; Ye, Guang-Hua; Xiao, Min

2010-12-01

To explore arsenic-induced oxidative stress and the protective efficacy of α-lipoic acid and vitamin c. 50 male SD rats were randomly divided into 5 groups. Ten rats (the control group) were exposed to deionized water for 6 weeks, and the others were alone exposed to sodium arsenite (50 mg/L water) for 6 weeks, at the same time, three group rats were administered intragastrically (i.g.) with α-lipoic acid 10 mg×kg(-1)×d(-1) and vitamin C 25 mg×kg(-1)×d(-1) either alone or in combination. At the end of experiment, blood was drawn from abdominal aorta, and then the blood, brain and liver of rats were used for biochemical assays, including blood glutathione (GSH), δ-aminolevulinic acid dehydratase (δ-ALAD ), reactive oxygen species (ROS) and oxidized glutathione (GSSG) level. At the same time, the super oxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity, catalase (CAT) activity, ATPase activity of brain and liver were determined. The caspase activity of brain were also determined. There were a significant increase in ROS level (P < 0.05), but a significant decrease in δ-ALAD activity (P < 0.01) in the chronic arsenic toxicity model group compared with the control group. These alterations were marginally restored by co-administration of vitamin C and α-lipoic acid individually, while significant recovery was observed in the animals supplemented with both the antioxidants together with arsenite in rat (P < 0.05). At the same time, there was a significant increase in the ROS and TBARS level of the brain and liver (P < 0.05), and caspase activity of the brain (P < 0.05), while there was a significant decrease in antioxidant enzymes and ATPase activity on arsenite exposure in rats (P < 0.05). These alterations were also marginally restored by co-administration of vitamin C and α-lipoic acid individually, while significant recovery was observed in the animals supplemented with both the antioxidants together with arsenite in rat (P < 0

Regenerating an Arsenic Removal Iron-Based Adsorptive ...

EPA Pesticide Factsheets

Adsorptive media technology is a frequently used method of removing arsenic by small water systems because of its simplicity and efficiency. Current practice is to replace the media when it no longer reduces arsenic below the USEPA drinking water maximum contaminant level (MCL) of 10 µg/L. Media replacement typically accounts for approximately 80% of the total operational and maintenance (O/M) costs. This cost can be substantial and cost prohibitive for many small systems. One potential option to reduce the cost is on-site regeneration and reuse of the media. To evaluate the regeneration option, three consecutive regeneration studies were conducted on a full scale 295 gpm arsenic removal adsorptive media system. This paper, of a two part series, describes the regeneration process and its effectiveness to strip the arsenic and other contaminants from an exhausted media. The results of the regeneration studies found that a three step regeneration process of media backwash, caustic regeneration and acid neutralization/conditioning is very effective for stripping arsenic and other contaminants from the exhaustive media of a full scale arsenic removal system This paper, of a two part series, describes the regeneration process and its effectiveness to strip the arsenic and other contaminants from an exhausted media

Associations between toenail arsenic concentration and dietary factors in a New Hampshire population.

PubMed

Gruber, Joann F; Karagas, Margaret R; Gilbert-Diamond, Diane; Bagley, Pamela J; Zens, M Scot; Sayarath, Vicki; Punshon, Tracy; Morris, J Steven; Cottingham, Kathryn L

2012-06-29

Dietary factors such as folate, vitamin B12, protein, and methionine are important for the excretion of arsenic via one-carbon metabolism in undernourished populations exposed to high levels of arsenic via drinking water. However, the effects of dietary factors on toenail arsenic concentrations in well-nourished populations exposed to relatively low levels of water arsenic are unknown. As part of a population-based case-control study of skin and bladder cancer from the USA, we evaluated relationships between consumption of dietary factors and arsenic concentrations in toenail clippings. Consumption of each dietary factor was determined from a validated food frequency questionnaire. We used general linear models to examine the associations between toenail arsenic and each dietary factor, taking into account potentially confounding effects. As expected, we found an inverse association between ln-transformed toenail arsenic and consumption of vitamin B12 (excluding supplements) and animal protein. Unexpectedly, there were also inverse associations with numerous dietary lipids (e.g., total fat, total animal fat, total vegetable fat, total monounsaturated fat, total polyunsaturated fat, and total saturated fat). Finally, increased toenail arsenic concentrations were associated with increased consumption of long chain n-3 fatty acids. In a relatively well-nourished population exposed to relatively low levels of arsenic via water, consumption of certain dietary lipids may decrease toenail arsenic concentration, while long chain n-3 fatty acids may increase toenail arsenic concentration, possibly due to their association with arsenolipids in fish tissue.

Associations between toenail arsenic concentration and dietary factors in a New Hampshire population

PubMed Central

2012-01-01

Background Dietary factors such as folate, vitamin B12, protein, and methionine are important for the excretion of arsenic via one-carbon metabolism in undernourished populations exposed to high levels of arsenic via drinking water. However, the effects of dietary factors on toenail arsenic concentrations in well-nourished populations exposed to relatively low levels of water arsenic are unknown. Methods As part of a population-based case–control study of skin and bladder cancer from the USA, we evaluated relationships between consumption of dietary factors and arsenic concentrations in toenail clippings. Consumption of each dietary factor was determined from a validated food frequency questionnaire. We used general linear models to examine the associations between toenail arsenic and each dietary factor, taking into account potentially confounding effects. Results As expected, we found an inverse association between ln-transformed toenail arsenic and consumption of vitamin B12 (excluding supplements) and animal protein. Unexpectedly, there were also inverse associations with numerous dietary lipids (e.g., total fat, total animal fat, total vegetable fat, total monounsaturated fat, total polyunsaturated fat, and total saturated fat). Finally, increased toenail arsenic concentrations were associated with increased consumption of long chain n-3 fatty acids. Conclusion In a relatively well-nourished population exposed to relatively low levels of arsenic via water, consumption of certain dietary lipids may decrease toenail arsenic concentration, while long chain n-3 fatty acids may increase toenail arsenic concentration, possibly due to their association with arsenolipids in fish tissue. PMID:22747713

Dynamic desorption of arsenic from polymer-supported hydrated iron(III) oxide in a wastewater treatment plant.

PubMed

Hu, Jian-Long; Yang, Xiao-Song; Liu, Ting; Shao, Li-Nan; Zhang, Wang

2017-11-01

Polymer-supported hydrated iron(III) oxide (PHIO) was successfully applied as adsorbent for arsenic removal in a wastewater treatment plant in Nandan, China. The practical PHIO adsorbent samples (PHIO-P) were collected from the adsorption column of the wastewater treatment plant, and desorption experiments of the adsorbent were carried out. Our results showed that the formation of precipitates on the surface of PHIO-P might block the porous channel of the adsorbent and decrease its arsenic adsorption capacity. In the dynamic arsenic desorption experiment, the arsenic desorption equilibrium was achieved more quickly at decreasing desorption velocity, and higher arsenic desorption efficiency was obtained at increasing NaOH concentration in regenerant. It was found that the PHIO-P adsorbent could be well regenerated at 1.0 M NaOH solution and desorption velocity of 5 BV h -1 . Comparing with the raw adsorbent, the maximum arsenic adsorption capacity of PHIO-P decreased by 41.1% after practical running for 26 months. Additionally, the frequently used waste PHIO adsorbent could be treated as non-hazardous material in the arsenic-containing wastewater treatment process after long-time use.

Binational arsenic exposure survey: methodology and estimated arsenic intake from drinking water and urinary arsenic concentrations.

PubMed

Roberge, Jason; O'Rourke, Mary Kay; Meza-Montenegro, Maria Mercedes; Gutiérrez-Millán, Luis Enrique; Burgess, Jefferey L; Harris, Robin B

2012-04-01

The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic) and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L) whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001), urinary inorganic arsenic concentration (p < 0.001), and urinary sum of species (p < 0.001). Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

PubMed Central

Roberge, Jason; O’Rourke, Mary Kay; Meza-Montenegro, Maria Mercedes; Gutiérrez-Millán, Luis Enrique; Burgess, Jefferey L.; Harris, Robin B.

2012-01-01

The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic) and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L) whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001), urinary inorganic arsenic concentration (p < 0.001), and urinary sum of species (p < 0.001). Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated. PMID:22690182

IDENTIFICATION OF INTERSPECIES CONCORDANCE OF MECHANISMS OF ARSENIC INDUCED BLADDER CANCER BY GENE EXPRESSION.

EPA Science Inventory

Arsenic is a human carcinogen that induces urinary bladder cancer. Several mechanisms have been proposed for arsenic-induced cancer. Although inorganic arsenic (iAs) does not induce tumors in adult rodents, dimethylarsinic acid (DMA), a major metabolite of iAs, is a rat bladder c...

Interaction between arsenic exposure from drinking water and genetic susceptibility in carotid intima–media thickness in Bangladesh

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Fen; Department of Environmental Medicine, New York University School of Medicine, New York, NY; Jasmine, Farzana

Epidemiologic studies that evaluated genetic susceptibility for the effects of arsenic exposure from drinking water on subclinical atherosclerosis are limited. We conducted a cross-sectional study of 1078 participants randomly selected from the Health Effects of Arsenic Longitudinal Study in Bangladesh to evaluate whether the association between arsenic exposure and carotid artery intima–media thickness (cIMT) differs by 207 single-nucleotide polymorphisms (SNPs) in 18 genes related to arsenic metabolism, oxidative stress, inflammation, and endothelial dysfunction. Although not statistically significant after correcting for multiple testing, nine SNPs in APOE, AS3MT, PNP, and TNF genes had a nominally statistically significant interaction with well-water arsenicmore » in cIMT. For instance, the joint presence of a higher level of well-water arsenic (≥ 40.4 μg/L) and the GG genotype of AS3MT rs3740392 was associated with a difference of 40.9 μm (95% CI = 14.4, 67.5) in cIMT, much greater than the difference of cIMT associated with the genotype alone (β = − 5.1 μm, 95% CI = − 31.6, 21.3) or arsenic exposure alone (β = 7.2 μm, 95% CI = − 3.1, 17.5). The pattern and magnitude of the interactions were similar when urinary arsenic was used as the exposure variable. Additionally, the at-risk genotypes of the AS3MT SNPs were positively related to the proportion of monomethylarsonic acid (MMA) in urine, which is indicative of arsenic methylation capacity. The findings provide novel evidence that genetic variants related to arsenic metabolism may play an important role in arsenic-induced subclinical atherosclerosis. Future replication studies in diverse populations are needed to confirm the findings. - Highlights: • Nine SNPs had a nominally significant interaction with well-water arsenic in cIMT. • Three SNPs in AS3MT showed nominally significant interactions with urinary arsenic. • cIMT was much higher among subjects with higher arsenic exposure and

Arsenic Metabolism in Children Differs From That in Adults.

PubMed

Skröder Löveborn, Helena; Kippler, Maria; Lu, Ying; Ahmed, Sultan; Kuehnelt, Doris; Raqib, Rubhana; Vahter, Marie

2016-07-01

Arsenic toxicity in adults is associated with methylation efficiency, influenced by factors such as gender, genetics, and nutrition. The aim of this study was to evaluate influencing factors for arsenic metabolism in children. For 488 children (9 years), whose mothers participated in a study on arsenic exposure during pregnancy (nested into the MINIMat trial) in rural Bangladesh, we measured urinary concentrations of inorganic arsenic (iAs) and its metabolites methylarsonic acid (MMA) and dimethylarsinic acid (DMA) by HPLC-HG-ICPMS. Methylation efficiency was assessed by relative amounts (%) of the metabolites. We evaluated the impact of factors such as maternal urinary metabolite pattern, arsenic exposure, gender, socioeconomic status, season of sampling, and nutritional factors, including erythrocyte selenium (Ery-Se), and plasma folate and vitamin B12.Children had higher %DMA and lower %iAs in urine compared to their mothers, unrelated to their lower exposure [median urinary arsenic (U-As) 53 vs 78 µg/l]. Surprisingly, selenium status (Ery-Se) was strongly associated with children's arsenic methylation; an increase in Ery-Se from the 5-95th percentile was associated with: +1.8 percentage points (pp) for %iAs (P  =  .001), +1.4 pp for %MMA (P  =  .003), and -3.2 pp for %DMA (P  <  .001). Despite this, Ery-Se was positively associated with U-As (5-95th percentile: +41 µg/l, P  =  .026). As expected, plasma folate was inversely associated with %iAs (5-95th percentile: -1.9 pp, P  =  .001) and positively associated with %DMA (5-95th percentile: +2.2 pp, P  =  .008). Children methylated arsenic more efficiently than their mothers. Also influencing factors, mainly selenium and folate, differed. This warrants further research. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology.

Arsenic Metabolism in Children Differs From That in Adults

PubMed Central

Skröder Löveborn, Helena; Lu, Ying; Ahmed, Sultan; Kuehnelt, Doris; Raqib, Rubhana; Vahter, Marie

2016-01-01

Arsenic toxicity in adults is associated with methylation efficiency, influenced by factors such as gender, genetics, and nutrition. The aim of this study was to evaluate influencing factors for arsenic metabolism in children. For 488 children (9 years), whose mothers participated in a study on arsenic exposure during pregnancy (nested into the MINIMat trial) in rural Bangladesh, we measured urinary concentrations of inorganic arsenic (iAs) and its metabolites methylarsonic acid (MMA) and dimethylarsinic acid (DMA) by HPLC-HG-ICPMS. Methylation efficiency was assessed by relative amounts (%) of the metabolites. We evaluated the impact of factors such as maternal urinary metabolite pattern, arsenic exposure, gender, socioeconomic status, season of sampling, and nutritional factors, including erythrocyte selenium (Ery-Se), and plasma folate and vitamin B12. Children had higher %DMA and lower %iAs in urine compared to their mothers, unrelated to their lower exposure [median urinary arsenic (U-As) 53 vs 78 µg/l]. Surprisingly, selenium status (Ery-Se) was strongly associated with children’s arsenic methylation; an increase in Ery-Se from the 5–95th percentile was associated with: +1.8 percentage points (pp) for %iAs (P  =  .001), +1.4 pp for %MMA (P  =  .003), and −3.2 pp for %DMA (P  <  .001). Despite this, Ery-Se was positively associated with U-As (5–95th percentile: +41 µg/l, P  =  .026). As expected, plasma folate was inversely associated with %iAs (5–95th percentile: −1.9 pp, P  =  .001) and positively associated with %DMA (5–95th percentile: +2.2 pp, P  =  .008). Children methylated arsenic more efficiently than their mothers. Also influencing factors, mainly selenium and folate, differed. This warrants further research. PMID:27056082

Arsenic Remediation Enhancement Through Chemical Additions to Pump and Treat Operations

NASA Astrophysics Data System (ADS)

Wovkulich, K.; Mailloux, B. J.; Stute, M.; Simpson, H. J.; Keimowitz, A. R.; Powell, A.; Lacko, A.; Chillrud, S. N.

2008-12-01

Arsenic is a contaminant found at more than 500 US Superfund sites. Since pump and treat technologies are widely used for remediation of contaminated groundwater, increasing the efficiency of contaminant removal at such sites should allow limited financial resources to clean up more sites. The Vineland Chemical Company Superfund site is extensively contaminated with arsenic after waste arsenic salts were stored and disposed of improperly for much of the company's 44 year manufacturing lifetime. Despite approximately eight years of pump and treat remediation, arsenic concentrations in the recovery wells can still be greater than 1000 ppb. The arsenic concentrations in the groundwater remain high because of slow desorption of arsenic from contaminated aquifer solids. Extrapolation of laboratory column experiments suggest that continuing the current groundwater remediation practice based on flushing ambient groundwater through the system may require on the order of hundreds of years to clean the site. However, chemical additions of phosphate or oxalic acid into the aquifer could decrease the remediation time scale substantially. Laboratory results from a soil column experiment using input of 10 mM oxalic acid suggest that site clean up of groundwater could be decreased to as little as four years. Pilot scale forced gradient field experiments will help establish whether chemical additions can be effective for increasing arsenic mobilization from aquifer solids and thus substantially decrease pump and treat clean up time.

Arsenic induced toxicity in broiler chicks and its alleviation with ascorbic acid: a toxico-patho-biochemical study

USGS Publications Warehouse

Khan, Ahrar; Sharaf, Rabia; Khan, Muhammad Zargham; Saleemi, Muhammad Kashif; Mahmood, Fazal

2013-01-01

To find out toxico-pathological effects of arsenic (As) and ameliorating effect of ascorbic acid (Vit C), broilers birds were administered 50 and 250 mg/kg arsenic and Vit C, respectively alone/in combination. As-treated birds exhibited severe signs of toxicity such as dullness, depression, increased thirst, open mouth breathing and watery diarrhea. All these signs were partially ameliorated with the treatment of Vit C. As-treated birds showed a significant decrease in serum total proteins while serum enzymes, urea and creatinine were significantly increased. Alkaline phosphatase and lactate dehydrogenase completely whereas proteins, aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea and creatinine were partial ameliorated in birds treated with As+Vit C as compared to As-treated and control birds. Pale and hemorrhagic liver and swollen kidneys were observed in As-treated birds. Histopathologically, liver exhibited congestion and cytoplasmic vacuolation while in kidneys, condensation of tubular epithelium nuclei, epithelial necrosis, increased urinary spaces, sloughing of tubules from basement membrane and cast deposition were observed in As-treated birds. Pathological lesions were partially ameliorated with the treatment of Vit C. It can be concluded that arsenic induces biochemical and histopathological alterations in broiler birds; however, these toxic effects can be partially attenuated by Vit C.

Practical performance and its efficiency of arsenic removal from groundwater using Fe-Mn binary oxide.

PubMed

Chang, Fangfang; Qu, Jiuhui; Liu, Ruiping; Zhao, Xu; Lei, Pengju

2010-01-01

A treatment unit packed by granular adsorbent of Fe-Mn binary oxide incorporated into diatomite (FMBO(1:1)-diatomite) was studied to remove arsenic from anaerobic groundwater without any pre-treatment or post-treatment. The raw anaerobic groundwater containing 35-45 microg/L of arsenic was collected from suburb of Beijing. Arsenic (III) constituted roughly 60%-80% of the total arsenic content. Approximately 7,000 bed volumes (ratio of effluent volume to adsorbent volume) treated water with arsenic concentration below 10 microg/L were produced in the operation period of four months. The regeneration of FMBO (1:1)-diatomite had been operated for 15 times. In the first stage, the regeneration process significantly improved the adsorption capacity of FMBO (1:1)-diatomite. With increased loading amount of Fe-Mn binary oxide, the adsorption capacity for arsenic decreased 20%-40%. Iron and manganese in anaerobic groundwater were oxidized and adsorptive filtrated by FMBO (1:1)-diatomite efficiently. The final concentrations of iron and manganese in effluents were nearly zero. The continued safe performance of the treatment units proved that adsorbent FMBO (1:1)-diatomite had high oxidation ability and exhibited strong adsorptive filtration.

In situ treatment of arsenic-contaminated groundwater by air sparging.

PubMed

Brunsting, Joseph H; McBean, Edward A

2014-04-01

Arsenic contamination of groundwater is a major problem in some areas of the world, particularly in West Bengal (India) and Bangladesh where it is caused by reducing conditions in the aquifer. In situ treatment, if it can be proven as operationally feasible, has the potential to capture some advantages over other treatment methods by being fairly simple, not using chemicals, and not necessitating disposal of arsenic-rich wastes. In this study, the potential for in situ treatment by injection of compressed air directly into the aquifer (i.e. air sparging) is assessed. An experimental apparatus was constructed to simulate conditions of arsenic-rich groundwater under anaerobic conditions, and in situ treatment by air sparging was employed. Arsenic (up to 200 μg/L) was removed to a maximum of 79% (at a local point in the apparatus) using a solution with dissolved iron and arsenic only. A static "jar" test revealed arsenic removal by co-precipitation with iron at a molar ratio of approximately 2 (iron/arsenic). This is encouraging since groundwater with relatively high amounts of dissolved iron (as compared to arsenic) therefore has a large theoretical treatment capacity for arsenic. Iron oxidation was significantly retarded at pH values below neutral. In terms of operation, analysis of experimental results shows that periodic air sparging may be feasible. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessment of total arsenic and arsenic species stability in alga samples and their aqueous extracts.

PubMed

García Salgado, S; Quijano Nieto, M A; Bonilla Simón, M M

2008-05-30

In order to achieve reliable information on speciation analysis, it is necessary to assess previously the species stability in the sample to analyse. Furthermore, in those cases where the sample treatment for species extraction is time-consuming, an assessment of the species integrity in the extracts is of paramount importance. Thus, the present paper reports total arsenic and arsenic species stability in alga samples (Sargassum fulvellum and Hizikia fusiformis), as well as in their aqueous extracts, which were stored in amber glass and polystyrene containers at different temperatures. Total arsenic determination was carried out by inductively coupled plasma atomic emission spectroscopy (ICP-AES), after sample acid digestion in a microwave oven, while arsenic speciation was conducted by anion exchange high performance liquid chromatography on-line coupled to ICP-AES, with and without sample introduction by hydride generation (HPLC-ICP-AES and HPLC-HG-ICP-AES), after aqueous microwave-assisted extraction. The results obtained for solid alga samples showed that total arsenic (for Hijiki alga) and arsenic species present (As(V) for Hijiki and NIES No. 9 Sargasso) are stable for at least 12 months when samples are stored in polystyrene containers at +20 degrees C. On the other hand, a different behaviour was observed in the stability of total arsenic and As(V) species in aqueous extracts for both samples, being the best storage conditions for Sargasso extracts a temperature of -18 degrees C and polystyrene containers, under which they are stable for at least 15 days, while Hijiki extracts must be stored in polystyrene containers at +4 degrees C in order to ensure the stability for 10 days.

Heat-assisted aqueous extraction of rice flour for arsenic speciation analysis.

PubMed

Narukawa, Tomohiro; Chiba, Koichi

2010-07-28

A versatile heat-assisted pretreatment aqueous extraction method for the analysis of arsenic species in rice was developed. Rice flour certified reference materials NIST SRM1568a and NMIJ CRM 7503-a and a flour made from polished rice were used as samples, and HPLC-ICP-MS was employed for the determination of arsenic species. Arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) were detected in NIST SRM, and As(III), As(V) and DMAA were found in NMIJ CRM and the prepared polished rice flour. The sums of the concentrations of all species in each rice flour sample were 97-102% of the total arsenic concentration in each sample.

GSTO and AS3MT genetic polymorphisms and differences in urinary arsenic concentrations among residents in Bangladesh.

PubMed

Rodrigues, Ema G; Kile, Molly; Hoffman, Elaine; Quamruzzaman, Quazi; Rahman, Mahmuder; Mahiuddin, Golam; Hsueh, Yumei; Christiani, David C

2012-05-01

We determined whether single nucleotide polymorphisms (SNPs) in the glutathione S-transferase omega (GSTO) and arsenic(III)methyltransferase (AS3MT) genes were associated with concentrations of urinary arsenic metabolites among 900 individuals without skin lesions in Bangladesh. Four SNPs were assessed in these genes. A pathway analysis evaluated the association between urinary arsenic metabolites and SNPs. GSTO1 rs4925 homozygous wild type was significantly associated with higher monomethylarsonic acid (MMA) and dimethylarsinic acid urinary concentrations, whereas wild-type AS3MT rs11191439 had significantly lower levels of As(III) and MMA. Genetic polymorphisms GSTO and As3MT modify arsenic metabolism as evidenced by altered urinary arsenic excretion.

ARSENIC INDUCTION OF HEME OXYGENASE AS A BIOMARKER

EPA Science Inventory

Useful biomarkers of arsenic effects in both experimental animals and humans are needed. Arsenate and arsenite are good inducers of rat hepatic and renal heme oxygenase (HO); monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) are not. Therefore, HO enzyme induction ...

Arsenic speciation in newberyite (MgHPO(4)·3H(2)O) determined by synchrotron X-ray absorption and electron paramagnetic resonance spectroscopies: implications for the fate of arsenic in green fertilizers.

PubMed

Lin, Jinru; Chen, Ning; Pan, Yuanming

2014-06-17

Newberyite (MgHPO4·3H2O), a biomineral and common constituent in guano deposits, is an important decomposition product of struvite that is an increasingly popular green fertilizer recovered from wastewaters. Two samples of newberyite containing 1099 and 25 ppm As have been obtained at pH = 6.4, by using Na2HAsO4·7H2O and NaAsO2 as the dopant, respectively (i.e., Synthesis 1 and Synthesis 2). Synchrotron arsenic K-edge X-ray absorption spectroscopic data of newberyite from Synthesis 1 show that As(5+) is dominant and has a local environment typical of the arsenate species. Single-crystal electron paramagnetic resonance (EPR) spectra of gamma-ray-irradiated newberyite from Synthesis 1 contain two arsenic-associated oxyradicals: [AsO3](2-) and [AsO2](2-) derived from As(5+) and As(3+), respectively, at the P site. Quantitative analyses of powder EPR spectra allow determinations of the As(5+) and As(3+) contents in newberyite from Synthesis 1 and Synthesis 2. Elevated concentrations of arsenic also occur in natural newberyite transformed from struvite in guano deposits and record the accumulation of this metalloid in the food chain. Therefore, newberyite, which sequesters As during crystallization and retains this metalloid during the transformation from struvite, can attenuate arsenic contamination from green fertilizers in moderately acidic soils. Also, the capacity for accommodating both As(5+) and As(3+) in the crystal lattice coupled with simple chemistry and easy crystallization at ambient conditions makes newberyite an attractive material for remediation of arsenic contamination in aqueous environments.

Greenhouse study on the phytoremediation potential of vetiver grass, Chrysopogon zizanioides L., in arsenic-contaminated soils.

PubMed

Datta, Rupali; Quispe, Mario A; Sarkar, Dibyendu

2011-01-01

The purpose of this greenhouse study was to assess the capacity of vetiver grass to accumulate arsenic from pesticide-contaminated soils of varying physico-chemical properties. Results indicate that vetiver is capable of tolerating moderate levels of arsenic up to 225 mg/kg. Plant growth and arsenic removal efficiency was strongly influenced by soil properties. Arsenic removal was highest (10.6%) in Millhopper soil contaminated with 45 mg/kg arsenic, which decreased to 4.5 and 0.6% at 225 and 450 mg/kg, respectively. High biomass, widespread root system and environmental tolerance make this plant an attractive choice for the remediation of soils contaminated with moderate levels of arsenic.

Microbial Methylation of Metalloids: Arsenic, Antimony, and Bismuth

PubMed Central

Bentley, Ronald; Chasteen, Thomas G.

2002-01-01

A significant 19th century public health problem was that the inhabitants of many houses containing wallpaper decorated with green arsenical pigments experienced illness and death. The problem was caused by certain fungi that grew in the presence of inorganic arsenic to form a toxic, garlic-odored gas. The garlic odor was actually put to use in a very delicate microbiological test for arsenic. In 1933, the gas was shown to be trimethylarsine. It was not until 1971 that arsenic methylation by bacteria was demonstrated. Further research in biomethylation has been facilitated by the development of delicate techniques for the determination of arsenic species. As described in this review, many microorganisms (bacteria, fungi, and yeasts) and animals are now known to biomethylate arsenic, forming both volatile (e.g., methylarsines) and nonvolatile (e.g., methylarsonic acid and dimethylarsinic acid) compounds. The enzymatic mechanisms for this biomethylation are discussed. The microbial conversion of sodium arsenate to trimethylarsine proceeds by alternate reduction and methylation steps, with S-adenosylmethionine as the usual methyl donor. Thiols have important roles in the reductions. In anaerobic bacteria, methylcobalamin may be the donor. The other metalloid elements of the periodic table group 15, antimony and bismuth, also undergo biomethylation to some extent. Trimethylstibine formation by microorganisms is now well established, but this process apparently does not occur in animals. Formation of trimethylbismuth by microorganisms has been reported in a few cases. Microbial methylation plays important roles in the biogeochemical cycling of these metalloid elements and possibly in their detoxification. The wheel has come full circle, and public health considerations are again important. PMID:12040126

Urinary arsenic and porphyrin profile in C57BL/6J mice chronically exposed to monomethylarsonous acid (MMAIII) for two years.

PubMed

Krishnamohan, Manonmanii; Qi, Lixia; Lam, Paul K S; Moore, Michael R; Ng, Jack C

2007-10-01

Arsenicals are proven carcinogens in humans and it imposes significant health impacts on both humans and animals. Recently monomethylarsonous acid (MMA(III)), the toxic metabolite of arsenic has been identified in human urine and believed to be more acutely toxic than arsenite and arsenate. Arsenic also affects the activity of a number of haem biosynthesis enzymes. As a part of 2-year arsenic carcinogenicity study, young female C57BL/6J mice were given drinking water containing 0, 100, 250 and 500 microg/L arsenic as MMA(III)ad libitum. 24 h urine samples were collected at 0, 1, 2, 4, 8 weeks and every 8 weeks for up to 104 weeks. Urinary arsenic speciation and porphyrins were measured using HPLC-ICP-MS and HPLC with fluorescence detection respectively. DMA(V) was a major urinary metabolite detected. Significant dose-response relationship was observed between control and treatment groups after 1, 4, 24, 32, 48, 56, 88, 96 and 104 weeks. The level of uroporphyrin in 250 and 500 microg As/L group is significantly different from the control group after 4, 8, 16, 32, 56, 72, 80, 96 and 104 weeks. Coproporphyrin I level in 500 microAs/L group is significantly different from control group after 8, 24, 32, 40, 56, 72, 80, 88 and 104 weeks. After 4 weeks the level of coproporphyrin III concentration significantly increased in all the treatment groups compared to the control except week 16 and 48. Our results show urinary DMA(V) and porphyrin profile can be used as an early warning biomarker for chronic MMA(III) exposure before the onset of cancer.

Arsenic

MedlinePlus

... and minerals. Arsenic compounds are used to preserve wood, as pesticides, and in some industries. Arsenic can ... Breathing sawdust or burning smoke from arsenic-treated wood Living in an area with high levels of ...

Phytoremediation assessment of Gomphrena globosa and Zinnia elegans grown in arsenic-contaminated hydroponic conditions as a safe and feasible alternative to be applied in arsenic-contaminated soils of the Bengal Delta.

PubMed

Signes-Pastor, A J; Munera-Picazo, S; Burló, F; Cano-Lamadrid, M; Carbonell-Barrachina, A A

2015-06-01

Several agricultural fields show high contents of arsenic because of irrigation with arsenic-contaminated groundwater. Vegetables accumulate arsenic in their edible parts when grown in contaminated soils. Polluted vegetables are one of the main sources of arsenic in the food chain, especially for people living in rural arsenic endemic villages of India and Bangladesh. The aim of this study was to assess the feasibility of floriculture in the crop rotation system of arsenic endemic areas of the Bengal Delta. The effects of different arsenic concentrations (0, 0.5, 1.0, and 2.0 mg As L(-1)) and types of flowering plant (Gomphrena globosa and Zinnia elegans) on plant growth and arsenic accumulation were studied under hydroponic conditions. Total arsenic was quantified using atomic absorption spectrometer with hydride generation (HG-AAS). Arsenic was mainly accumulated in the roots (72 %), followed by leaves (12 %), stems (10 %), and flowers (<1 %). The flowering plants studied did not show as high phytoremediation capacities as other wild species, such as ferns. However, they behaved as arsenic tolerant plants and grew and bloomed well, without showing any phytotoxic signs. This study proves that floriculture could be included within the crop rotation system in arsenic-contaminated agricultural soils, in order to improve food safety and also food security by increasing farmer's revenue.

Bioconcentration and arsenic speciation analysis in ragworm, Hediste diversicolor (Muller 1776).

PubMed

Gaion, Andrea; Scuderi, Alice; Pellegrini, David; Sartori, Davide

2013-01-01

This study focused on bioconcentrations of arsenic in Hediste diversicolor (Müller 1776) after exposure to three different molecule solutions: arsenate, dimethyl-arsinate and arsenobetaine. Speciation analysis was carried out after exposing the organisms to these solutions in order to investigate their arsenic biotransformation capacity. Arsenic reached to the maximum level in these tissues after 15 days' exposure to a solution of 100 μg L(-1) of arsenobetaine, although a significant increase was obtained in worms exposed to arsenate. Speciation analysis shows that trimethyl-arsine oxide is the slowest detoxification phase recorded in experiment.

Enzyme-assisted extraction and liquid chromatography mass spectrometry for the determination of arsenic species in chicken meat.

PubMed

Liu, Qingqing; Peng, Hanyong; Lu, Xiufen; Le, X Chris

2015-08-12

Chicken is the most consumed meat in North America. Concentrations of arsenic in chicken range from μg kg(-1) to mg kg(-1). However, little is known about the speciation of arsenic in chicken meat. The objective of this research was to develop a method enabling determination of arsenic species in chicken breast muscle. We report here enzyme-enhanced extraction of arsenic species from chicken meat, separation using anion exchange chromatography (HPLC), and simultaneous detection with both inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization tandem mass spectrometry (ESIMS). We compared the extraction of arsenic species using several proteolytic enzymes: bromelain, papain, pepsin, proteinase K, and trypsin. With the use of papain-assisted extraction, 10 arsenic species were extracted and detected, as compared to 8 detectable arsenic species in the water/methanol extract. The overall extraction efficiency was also improved using a combination of ultrasonication and papain digestion, as compared to the conventional water/methanol extraction. Detection limits were in the range of 1.0-1.8 μg arsenic per kg chicken breast meat (dry weight) for seven arsenic species: arsenobetaine (AsB), inorganic arsenite (As(III)), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), inorganic arsenate (As(V)), 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone), and N-acetyl-4-hydroxy-m-arsanilic acid (NAHAA). Analysis of breast meat samples from six chickens receiving feed containing Roxarsone showed the presence of (mean±standard deviation μg kg(-1)) AsB (107±4), As(III) (113±7), As(V) (7±2), MMA (51±5), DMA (64±6), Roxarsone (18±1), and four unidentified arsenic species (approximate concentration 1-10 μg kg(-1)). Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of endogenous hydrogen peroxide and glutathione on the stability of arsenic metabolites in rat bile.

PubMed

Kobayashi, Yayoi; Hirano, Seishiro

2008-10-01

Trivalent arsenicals such as arsenite (iAs(III)), monomethylarsonous acid (MMA(III)) and dimethylarsinous acid (DMA(III)) are more toxic than analogous pentavalent compounds such as arsenate (iAs(V)), monomethylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)). It has been reported that arsenic-glutathione (As-GSH) complexes such as arsenic triglutathione (ATG) and methylarsenic diglutathione (MADG) are major metabolites in rat bile following intravenous administration of iAs(III). Recently, we have shown that both ATG and MADG are unstable and easily hydrolyzed to iAs(III) and MMA(III), respectively, and that MMA(III) is oxidized to MMA(V) in bile. In the present study we report the effects of H(2)O(2) and GSH on the stability of As-GSH complexes in rat bile. Male SD rats were injected intravenously with saline or iAs(III) at a dose of 0.2 or 2.0 mg As/kg body weight, and bile fluid was collected on ice for 30 min. To estimate the stability of As-GSH complexes in bile, ATG or MADG was added to untreated, heat-treated, catalase-treated, or dialyzed bile, and then incubated at 37 degrees C for 10 min. Concentrations of biliary H(2)O(2) and GSH in the higher dose group were 12.6- and 4.5-times higher than the control value, respectively. Exogenously added trivalent arsenicals were oxidized to pentavalent arsenicals in the bile depending on the biliary concentration of H(2)O(2). Both catalase and dialysis prevented oxidation of trivalent arsenicals to the corresponding pentavalent compounds. Exogenously added GSH stabilized As-GSH complexes in bile. These results suggest that H(2)O(2) converts trivalent arsenicals to less toxic pentavalent arsenicals, whereas GSH prevents hydrolysis of As-GSH complexes and the generation of unconjugated toxic trivalent arsenicals.

Comparison and trend study on acidity and acidic buffering capacity of particulate matter in China

NASA Astrophysics Data System (ADS)

Ren, Lihong; Wang, Wei; Wang, Qingyue; Yang, XiaoYang; Tang, Dagang

2011-12-01

The acidity of about 2000 particulate matter samples from aircraft and ground-based monitoring is analyzed by the method similar to soil acidity determination. The ground-based samples were collected at about 50 urban or background sites in northern and southern China. Moreover, the acidic buffering capacity of those samples is also analyzed by the method of micro acid-base titration. Results indicate that the acidity level is lower in most northern areas than those in the south, and the acidic buffering capacity showed inverse tendency, correspondingly. This is the most important reason why the pollution of acidic-precipitation is much more serious in Southern China than that in Northern China. The acidity increases and the acidic buffering capacity drops with the decreasing of the particle sizes, indicating that fine particle is the main influencing factor of the acidification. The ionic results show that Ca salt is the main alkaline substance in particulate matter, whereas the acidification of particulate matter is due to the SO 2 and NO x emitted from the fossil fuel burning. And among of them, coal burning is the main contributor of SO 2, however the contribution of NO x that emitted from fuel burning of motor vehicles has increased in recent years. By comparison of the experimental results during the past 20 years, it can be concluded that the acid precipitation of particulate matter has not been well controlled, and it even shows an increasing tendency in China lately. The acid precipitation of particulate matter has begun to frequently attack in part of the northern areas. Multiple regression analysis indicates that coefficient value of the ions is the lowest at the urban sites and the highest at the regional sites, whereas the aircraft measurement results are intermediate between those two kinds of sites.

Assessing the mechanisms controlling the mobilization of arsenic in the arsenic contaminated shallow alluvial aquifer in the blackfoot disease endemic area.

PubMed

Liao, Vivian Hsiu-Chuan; Chu, Yu-Ju; Su, Yu-Chen; Lin, Po-Cheng; Hwang, Yaw-Huei; Liu, Chen-Wuing; Liao, Chung-Min; Chang, Fi-John; Yu, Chan-Wei

2011-12-15

High levels of arsenic in groundwater and drinking water represent a major health problem worldwide. Drinking arsenic-contaminated groundwater is a likely cause of blackfoot disease (BFD) in Taiwan, but mechanisms controlling the mobilization of arsenic present at elevated concentrations within aquifers remain understudied. Microcosm experiments using sediments from arsenic contaminated shallow alluvial aquifers in the blackfoot disease endemic area showed simultaneous microbial reduction of Fe(III) and As(V). Significant soluble Fe(II) (0.23±0.03 mM) in pore waters and mobilization of As(III) (206.7±21.2 nM) occurred during the first week. Aqueous Fe(II) and As(III) respectively reached concentrations of 0.27±0.01 mM and 571.4±63.3 nM after 8 weeks. We also showed that the addition of acetate caused a further increase in aqueous Fe(II) but the dissolved arsenic did not increase. We further isolated an As(V)-reducing bacterium native to aquifer sediments which showed that the direct enzymatic reduction of As(V) to the potentially more-soluble As(III) in pore water is possible in this aquifer. Our results provide evidence that microorganisms can mediate the release of sedimentary arsenic to groundwater in this region and the capacity for arsenic release was not limited by the availability of electron donors in the sediments. Copyright © 2011 Elsevier B.V. All rights reserved.

Arsenic Species in Chicken Breast: Temporal Variations of Metabolites, Elimination Kinetics, and Residual Concentrations

PubMed Central

Liu, Qingqing; Peng, Hanyong; Lu, Xiufen; Zuidhof, Martin J.; Li, Xing-Fang; Le, X. Chris

2016-01-01

Background: Chicken meat has the highest per capita consumption among all meat types in North America. The practice of feeding 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, Rox) to chickens lasted for more than 60 years. However, the fate of Rox and arsenic metabolites remaining in chicken are poorly understood. Objectives: We aimed to determine the elimination of Rox and metabolites from chickens and quantify the remaining arsenic species in chicken meat, providing necessary information for meaningful exposure assessment. Methods: We have conducted a 35-day feeding experiment involving 1,600 chickens, of which half were control and the other half were fed a Rox-supplemented diet for the first 28 days and then a Rox-free diet for the final 7 days. We quantified the concentrations of individual arsenic species in the breast meat of 229 chickens. Results: Rox, arsenobetaine, arsenite, monomethylarsonic acid, dimethylarsinic acid, and a new arsenic metabolite, were detected in breast meat from chickens fed Rox. The concentrations of arsenic species, except arsenobetaine, were significantly higher in the Rox-fed than in the control chickens. The half-lives of elimination of these arsenic species were 0.4–1 day. Seven days after termination of Rox feeding, the concentrations of arsenite (3.1 μg/kg), Rox (0.4 μg/kg), and a new arsenic metabolite (0.8 μg/kg) were significantly higher in the Rox-fed chickens than in the control. Conclusion: Feeding of Rox to chickens increased the concentrations of five arsenic species in breast meat. Although most arsenic species were excreted rapidly when the feeding of Rox stopped, arsenic species remaining in the Rox-fed chickens were higher than the background levels. Citation: Liu Q, Peng H, Lu X, Zuidhof MJ, Li XF, Le XC. 2016. Arsenic species in chicken breast: temporal variations of metabolites, elimination kinetics, and residual concentrations. Environ Health Perspect 124:1174–1181; http://dx.doi.org/10.1289/ehp

Arsenic Species in Chicken Breast: Temporal Variations of Metabolites, Elimination Kinetics, and Residual Concentrations.

PubMed

Liu, Qingqing; Peng, Hanyong; Lu, Xiufen; Zuidhof, Martin J; Li, Xing-Fang; Le, X Chris

2016-08-01

Chicken meat has the highest per capita consumption among all meat types in North America. The practice of feeding 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, Rox) to chickens lasted for more than 60 years. However, the fate of Rox and arsenic metabolites remaining in chicken are poorly understood. We aimed to determine the elimination of Rox and metabolites from chickens and quantify the remaining arsenic species in chicken meat, providing necessary information for meaningful exposure assessment. We have conducted a 35-day feeding experiment involving 1,600 chickens, of which half were control and the other half were fed a Rox-supplemented diet for the first 28 days and then a Rox-free diet for the final 7 days. We quantified the concentrations of individual arsenic species in the breast meat of 229 chickens. Rox, arsenobetaine, arsenite, monomethylarsonic acid, dimethylarsinic acid, and a new arsenic metabolite, were detected in breast meat from chickens fed Rox. The concentrations of arsenic species, except arsenobetaine, were significantly higher in the Rox-fed than in the control chickens. The half-lives of elimination of these arsenic species were 0.4-1 day. Seven days after termination of Rox feeding, the concentrations of arsenite (3.1 μg/kg), Rox (0.4 μg/kg), and a new arsenic metabolite (0.8 μg/kg) were significantly higher in the Rox-fed chickens than in the control. Feeding of Rox to chickens increased the concentrations of five arsenic species in breast meat. Although most arsenic species were excreted rapidly when the feeding of Rox stopped, arsenic species remaining in the Rox-fed chickens were higher than the background levels. Liu Q, Peng H, Lu X, Zuidhof MJ, Li XF, Le XC. 2016. Arsenic species in chicken breast: temporal variations of metabolites, elimination kinetics, and residual concentrations. Environ Health Perspect 124:1174-1181; http://dx.doi.org/10.1289/ehp.1510530.

Total arsenic determination and speciation in infant food products by ion chromatography-inductively coupled plasma-mass spectrometry.

PubMed

Vela, Nohora P; Heitkemper, Douglas T

2004-01-01

Health risk associated with dietary arsenic intake may be different for infants and adults. Seafood is the main contributor to arsenic intake for adults while terrestrial-based food is the primary source for infants. Processed infant food products such as rice-based cereals, mixed rice/formula cereals, milk-based infant formula, applesauce and puree of peaches, pears, carrots, sweet potatoes, green beans, and squash were evaluated for total and speciated arsenic content. Arsenic concentrations found in rice-based cereals (63-320 ng/g dry weight) were similar to those reported for raw rice. Results for the analysis of powdered infant formula by inductively coupled plasma-mass spectrometry (ICP-MS) indicated a narrow and low arsenic concentration range (12 to 17 ng/g). Arsenic content in puree infant food products, including rice cereals, fruits, and vegetables, varies from <1 to 24 ng/g wet weight. Sample treatment with trifluoroacetic acid at 100 degrees C were an efficient and mild method for extraction of arsenic species present in different food matrixes as compared to alternative methods that included sonication and accelerated solvent extraction. Extraction recoveries from 94 to 128% were obtained when the summation of species was compared to total arsenic. The ion chromatography (IC)-ICP-MS method selected for arsenic speciation allowed for the quantitative determination of inorganic arsenic [As(III) + As(V)], dimethylarsinic acid (DMA), and methylarsonic acid (MMA). Inorganic arsenic and DMA are the main species found in rice-based and mixed rice/formula cereals, although traces of MMA were also detected. Inorganic arsenic was present in freeze-dried sweet potatoes, carrots, green beans, and peaches. MMA and DMA were not detected in these samples. Arsenic species in squash, pears, and applesauce were not detected above the method detection limit [5 ng/g dry weight for As(III), MMA, and DMA and 10 ng/g dry weight for As(V)].

The Investigation of Unexpected Arsenic Compounds Observed in Routine Biological Monitoring Urinary Speciation Analysis

PubMed Central

Leese, Elizabeth; Clench, Malcolm; Morton, Jackie; Gardiner, Philip H.E.; Carolan, Vikki A.

2017-01-01

This study investigates the identity of two unexpected arsenic species found separately in a number of urine samples sent to the Health and Safety Executive’s Health and Safety Laboratory for arsenic speciation (arsenobetaine, AB; arsenite, As3+; arsenate, As5+; monomethylarsonic acid, MMA5+; and dimethylarsinic acid, DMA5+). Micro liquid chromatography coupled to inductively coupled plasma mass spectrometry (µLC-ICP-MS) and electrospray time of flight tandem mass spectrometry (ESI-QqTOF-MS/MS) were used to identify the two arsenic peaks by comparison to several characterized arsenicals: arsenocholine, AC; trimethyl arsine oxide, TMAO; dimethylarsenoacetate, DMAA; dimethylarsenoethanol, DMAE; thio-dimethylarsinate, thio-DMA; thio-dimethylarsenoacetate, thio-DMAA and thio-dimethylarsenoethanol, thio-DMAE. The results from both the ICP-MS and ESI-QqTOF-MS/MS investigations indicate that the unexpected arsenic species termed peak 1 was thio-DMA. While the unexpected arsenic species termed peak 2 has yet to be identified, this investigation shows that it was not AC, TMAO, DMAA, DMAE, thio-DMA, thio-DMAA or thio-DMAE. This study demonstrates the incidence of unexpected arsenic species in both routine and non-routine urine samples from both workers and hospital patients. PMID:29051444

Antioxidant capacity and phenolic acids of virgin coconut oil.

PubMed

Marina, A M; Man, Y B Che; Nazimah, S A H; Amin, I

2009-01-01

The antioxidant properties of virgin coconut oil produced through chilling and fermentation were investigated and compared with refined, bleached and deodorized coconut oil. Virgin coconut oil showed better antioxidant capacity than refined, bleached and deodorized coconut oil. The virgin coconut oil produced through the fermentation method had the strongest scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the highest antioxidant activity based on the beta-carotene-linoleate bleaching method. However, virgin coconut oil obtained through the chilling method had the highest reducing power. The major phenolic acids detected were ferulic acid and p-coumaric acid. Very high correlations were found between the total phenolic content and scavenging activity (r=0.91), and between the total phenolic content and reducing power (r=0.96). There was also a high correlation between total phenolic acids and beta-carotene bleaching activity. The study indicated that the contribution of antioxidant capacity in virgin coconut oil could be due to phenolic compounds.

Effect Of Soil Properties On The Geochemical Speciation Of Arsenic In Contaminated Soils: A Greenhouse Study

NASA Astrophysics Data System (ADS)

Sharma, S.; Sarkar, D.; Datta, R.

2005-05-01

Land-applied arsenical pesticides have contributed elevated soil arsenic (As) levels. Many baseline risk assessments As-contaminated sites assume that all As present in the soil is bioavailable, thereby potentially overestimating the actual health risk. However, risk from As exposure is associated only with those forms of As that are potentially extractable by the human gastrointestinal juices. It has been demonstrated that As may exist in several geochemical forms depending on soil chemical properties, which may or may not be bioavailable. The current study aims at addressing the issue of soil variability on As bioavailability as a function of soil physico-chemical properties in a greenhouse setting involving dynamic interactions between soil, water and plants. Four different soils were chosen based on their potential differences with respect to As reactivity: Immokalee, an acid sand with low extractable Fe/Al, having minimal arsenic retention capacity; Millhopper, an acid sandy loam with high extractable Fe/Al oxides; Pahokee Muck soil with 85% soil organic matter (SOM) as well as high Fe/Al content; and Orelia soil with high clay and Fe/Al content. Soils were amended with sodium arsenate (675 and 1500 mg/Kg). Rice (Oryza sativa) was used as the test crop. A sequential extraction scheme was employed to identify the geochemical forms of As in soils (soluble, exchangeable, organic, Fe/Al-bound, Ca/Mg-bound, residual) immediately after spiking; after 3 mo; and after 6 mo of equilibration time. Concentrations of these As forms were correlated with the in-vitro bioavailable As fractions to identify those As fractions that are most likely to be bioavailable. Results from this study showed that there was little to no plant growth in the contaminated soils. Sequential extractions of the soil indicated that arsenic is strongly adsorbed onto soil amorphous iron/aluminum oxides, and the degree of arsenic retention is a direct function of equilibration time.

Effect of Carbon Type on Arsenic and Trichloroethylene Removal Capacity of Iron (Hydr)oxide Nanoparticle Impregnated Granulated Activated Carbon

NASA Astrophysics Data System (ADS)

Cooper, Anne Marie

This study investigates the effect of the virgin granular activated carbon (GAC) on the properties of synthesized iron (hydr)oxide nanoparticles impregnated GAC (Fe-GAC) media and its ability to remove arsenate and organic trichloroethylene (TCE) from water. Fe-GAC media were synthesized from bituminous and lignite-based virgin GAC via three variations of a permanganate/Fe(II) synthesis method. Data obtained from an array of characterization techniques indicated that differences in pore size distribution and surface chemistry of the virgin GAC favor different reaction paths for the iron (hydr)oxide nanoparticles formation. Batch equilibrium isotherm testing (120 microg-As/L; 6 mg-TCE/L, 10 mM NaHCO3 at pH = 7.2 +/- 0.1 and pH = 8.2 +/- 0.1) showed arsenic removal capability was increased as a result of iron (nanoparticles) impregnation, while TCE removal properties were decreased in Fe-GAC media. This tradeoff was displayed by both lignite and bituminous Fe-GAC but was most pronounced in lignite-based Fe-GAC having the highest Fe content (13.4% Fe) which showed the most favorable Freundlich adsorption and intensity parameters for arsenic of Ka = 72.6 (microg-As/g-FeGAC)(L/microg-As)1/n, 1/n = 0.6; and least favorable adsorption for TCE of Ka = 0.8 (mg-TCE/g-FeGAC)(L/mg-TCE)1/n, 1/n = 4.47. It was concluded that iron content was the main factor contributing to enhanced arsenic removal and that this was affected by base GAC properties such as pore size distribution and surface functional groups. However high Fe content can result in pore blockage; reduction in available adsorption sites for organic co-contaminants; and have a significant effect on the Fe-GACs overall adsorption capacity.

Anticancer Activity of Small Molecule and Nanoparticulate Arsenic(III) Complexes

PubMed Central

Swindell, Elden P.; Hankins, Patrick L.; Chen, Haimei; Miodragović, Ðenana U.; O'Halloran, Thomas V.

2014-01-01

Starting in ancient China and Greece, arsenic-containing compounds have been used in the treatment of disease for over 3000 years. They were used for a variety of diseases in the 20th century, including parasitic and sexually transmitted illnesses. A resurgence of interest in the therapeutic application of arsenicals has been driven by the discovery that low doses of a 1% aqueous solution of arsenic trioxide (i.e. arsenous acid) leads to complete remission of certain types of leukemia. Since FDA approval of arsenic trioxide (As2O3) for treatment of acute promyelocytic leukemia (APL) in 2000, it has become a front line therapy in this indication. There are currently over 100 active clinical trials involving inorganic arsenic or organoarsenic compounds registered with the FDA for the treatment of cancers. New generations of inorganic and organometallic arsenic compounds with enhanced activity or targeted cytotoxicity are being developed to overcome some of the shortcomings of arsenic therapeutics, namely short plasma half-lives and narrow therapeutic window. PMID:24147771

Bioaccumulation of arsenic species in rays from the northern Adriatic Sea.

PubMed

Šlejkovec, Zdenka; Stajnko, Anja; Falnoga, Ingrid; Lipej, Lovrenc; Mazej, Darja; Horvat, Milena; Faganeli, Jadran

2014-12-01

The difference in arsenic concentration and speciation between benthic (Pteromylaeus bovinus, Myliobatis aquila) and pelagic rays (Pteroplatytrygon violacea) from the northern Adriatic Sea (Gulf of Trieste) in relation to their size (age) was investigated. High arsenic concentrations were found in both groups with tendency of more efficient arsenic accumulation in benthic species, particularly in muscle (32.4 to 362 µg·g-1 of total arsenic). This was attributed to species differences in arsenic access, uptake and retention. In liver most arsenic was present in a form of arsenobetaine, dimethylarsinic acid and arsenoipids, whereas in muscle mainly arsenobetaine was found. The good correlations between total arsenic/arsenobetaine and size reflect the importance of accumulation of arsenobetaine with age. Arsenobetaine is an analogue of glycine betaine, a known osmoregulator in marine animals and both are very abundant in mussels, representing an important source of food for benthic species P. bovinus and M. aquila.

Bioaccumulation of Arsenic Species in Rays from the Northern Adriatic Sea

PubMed Central

Šlejkovec, Zdenka; Stajnko, Anja; Falnoga, Ingrid; Lipej, Lovrenc; Mazej, Darja; Horvat, Milena; Faganeli, Jadran

2014-01-01

The difference in arsenic concentration and speciation between benthic (Pteromylaeus bovinus, Myliobatis aquila) and pelagic rays (Pteroplatytrygon violacea) from the northern Adriatic Sea (Gulf of Trieste) in relation to their size (age) was investigated. High arsenic concentrations were found in both groups with tendency of more efficient arsenic accumulation in benthic species, particularly in muscle (32.4 to 362 µg·g−1 of total arsenic). This was attributed to species differences in arsenic access, uptake and retention. In liver most arsenic was present in a form of arsenobetaine, dimethylarsinic acid and arsenoipids, whereas in muscle mainly arsenobetaine was found. The good correlations between total arsenic/arsenobetaine and size reflect the importance of accumulation of arsenobetaine with age. Arsenobetaine is an analogue of glycine betaine, a known osmoregulator in marine animals and both are very abundant in mussels, representing an important source of food for benthic species P. bovinus and M. aquila. PMID:25470025

Water hyacinth removes arsenic from arsenic-contaminated drinking water.

PubMed

Misbahuddin, Mir; Fariduddin, Atm

2002-01-01

Water hyacinth (Eichhornia crassipes) removes arsenic from arsenic-contaminated drinking water. This effect depends on several factors, such as the amount of water hyacinth, amount of arsenic present in the water, duration of exposure, and presence of sunlight and air. On the basis of the present study, the authors suggest that water hyacinth is useful for making arsenic-contaminated drinking water totally arsenic free. Water hyacinth provides a natural means of removing arsenic from drinking water at the household level without monetary cost.

Dynamic Buffer Capacity in Acid-Base Systems.

PubMed

Michałowska-Kaczmarczyk, Anna M; Michałowski, Tadeusz

The generalized concept of 'dynamic' buffer capacity β V is related to electrolytic systems of different complexity where acid-base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton-Robinson buffers, taken as examples.

Enrichment of arsenic transforming and resistant heterotrophic bacteria from sediments of two salt lakes in Northern Chile.

PubMed

Lara, José; Escudero González, Lorena; Ferrero, Marcela; Chong Díaz, Guillermo; Pedrós-Alió, Carlos; Demergasso, Cecilia

2012-05-01

Microbial populations are involved in the arsenic biogeochemical cycle in catalyzing arsenic transformations and playing indirect roles. To investigate which ecotypes among the diverse microbial communities could have a role in cycling arsenic in salt lakes in Northern Chile and to obtain clues to facilitate their isolation in pure culture, sediment samples from Salar de Ascotán and Salar de Atacama were cultured in diluted LB medium amended with NaCl and arsenic, at different incubation conditions. The samples and the cultures were analyzed by nucleic acid extraction, fingerprinting analysis, and sequencing. Microbial reduction of As was evidenced in all the enrichments carried out in anaerobiosis. The results revealed that the incubation factors were more important for determining the microbial community structure than arsenic species and concentrations. The predominant microorganisms in enrichments from both sediments belonged to the Firmicutes and Proteobacteria phyla, but most of the bacterial ecotypes were confined to only one system. The occurrence of an active arsenic biogeochemical cycle was suggested in the system with the highest arsenic content that included populations compatible with microorganisms able to transform arsenic for energy conservation, accumulate arsenic, produce H(2), H(2)S and acetic acid (potential sources of electrons for arsenic reduction) and tolerate high arsenic levels.

Toxic Compounds in Our Food: Arsenic Uptake By Rice and Potential Mitigation By Silicon

NASA Astrophysics Data System (ADS)

Seyfferth, A.; Gill, R.; Penido, E.

2014-12-01

Arsenic is a ubiquitous element in soils worldwide and has the potential to negatively impact human and ecosystem health under certain biogeochemical conditions. While arsenic is relatively immobile in most oxidized soils due to a high affinity for soil solids, arsenic becomes mobilized under reduced soil conditions due to the reductive dissolution of iron(III) oxides thereby releasing soil-bound arsenic. Since arsenic is a well-known carcinogen, this plant-soil process has the potential to negatively impact the lives of billions of rice consumers worldwide upon plant uptake and grain storage of released arsenic. Moreover, arsenic uptake by rice is excacerbated by the use of As-laden groundwater for rice irrigation. One proposed strategy to decrease arsenic uptake by rice plants is via an increase in dissolved silicon in paddy soil solution (pore-water), since silicic acid and arsenous acid share an uptake pathway. However, several soil processes that influence arsenic cycling may be affected by silicon including desorption from bulk soil, formation and mineralogy of iron(III) oxide plaque, and adsorption/desorption onto/from iron plaque; the effect of silicon on these soil processes will ultimately dictate the effectiveness of altered dissolved silicon in decreasing arsenic uptake at the root, which in turn dictates the concentration of arsenic found in grains. Furthermore, the source of silicon may impact carbon cycling and, in particular, methane emissions. Here, impacts of altered dissolved silicon on processes that affect rhizospheric biogeochemical cycling of arsenic and subsequent plant-uptake, and how it influences other biogeochemical cycles such as carbon and iron are investigated. We show that silicon can decrease arsenic uptake and grain storage under certain conditions, and that altered silicon affects the type of iron (III) oxide that comprises iron plaque.

Influence of humic acid on the removal of arsenate and arsenic by ferric chloride: effects of pH, As/Fe ratio, initial As concentration, and co-existing solutes.

PubMed

Kong, Yanli; Kang, Jing; Shen, Jimin; Chen, Zhonglin; Fan, Leitao

2017-01-01

The influence of humic acid (HA) on the removal of arsenic by FeCl 3 was systematically studied in this paper. Jar tests were performed to investigate the influence on arsenic during FeCl 3 coagulation of the pH adjusting method, the initial As/Fe ratio, the equilibrium As concentration, and co-occurring anions and cations. Compared with results in HA-free systems, the removal trends of arsenic in HA solutions were quite different. It was found that As(V) removal was higher at low equilibrium concentration, yet the opposite was true for As(III) removal. The presence of HA influenced the effective number of active sites for arsenic removal by FeCl 3 flocculation. In addition, in the presence of HA, the impacts of co-existing solutions on arsenic removal were also different from that of an HA-free system. This study examined the influence of co-occurring anions, such as phosphate, sulfate, and silicate on arsenic removal, depending on their ability to compete for sorption sites and to hinder or facilitate the aggregation of ferric hydroxide flocs. The presence of Ca 2+ or Cd 2+ significantly increased arsenic removal at higher pH. Low concentrations of dissolved HA and high concentrations of colloid affected the adsorption of arsenic onto iron oxide. The influence of HA on the adsorption of arsenic onto iron oxide primarily depended on the relative content of the dissolved and mineral combination states of HA and the interface combination forms.

[Chronic arsenicism].

PubMed

Bourgeais, A M; Avenel-Audran, M; Le Bouil, A; Bouyx, C; Allain, P; Verret, J L

2001-04-01

Arsenic is an ubiquitous natural element. Chronic and low level ingestion or inhalation may result in chronic arsenicism first characterized by skin changes. A 75 year old man, non-insulin-dependent diabetic, presented a diffuse hyperpigmentation with scattered white spots on the trunk. He complained of asthenia. Clinical diagnosis of chronic arsenicism was confirmed by arsenic determination in urine, plasma and phaneres. Thorough investigations led to discover very high arsenic levels in the own wine of the patient. This was probably the result of a wrong use of sodium arsenite-based fungicide, for cultivating his vine yard. Chronic arsenicism has become rare but it should always be kept in mind. Clinical presentation, with particular cutaneous features and routes of exposure are reviewed. Treatment is symptomatic. As arsenic is known to be a strong carcinogenic agent, patients with chronic arsenicism have to be followed up during a long time.

Methylation of inorganic arsenic in different mammalian species and population groups.

PubMed

Vahter, M

1999-01-01

Thousands of people in different parts of the world are exposed to arsenic via drinking water or contaminated soil or food. The high general toxic of arsenic has been known for centuries, and research during the last decades has shown that arsenic is a potent human carcinogen. However, most experimental cancer studies have failed to demonstrate carcinogenicity in experimental animals, indicating marked variation in sensitivity towards arsenic toxicity between species. It has also been suggested that there is a variation in susceptibility among human individuals. One reason for such variability in toxic response may be variation in metabolism. Inorganic arsenic is methylated in humans as well as animals and micro-organisms, but there are considerable differences between species and individuals. In many, but not all, mammalian species, inorganic arsenic is methylated to methylarsonic acid (MMA) and dimethylarsinic acid (DMA), which are more rapidly excreted in urine than is the inorganic arsenic, especially the trivalent form (AsIII, arsenite) which is highly reactive with tissue components. Absorbed arsenate (AsV) is reduced to trivalent arsenic (AsIII) before the methyl groups are attached. It has been estimated that as much as 50-70% of absorbed AsV is rapidly reduced to AsIII, a reaction which seems to be common for most species. In most experimental animal species, DMA is the main metabolite excreted in urine. Compared to human subjects, very little MMA is produced. However, the rate of methylation varies considerably between species, and several species, e.g. the marmoset monkey and the chimpanzee have been shown not to methylate inorganic arsenic at all. In addition, the marmoset monkey accumulates arsenic in the liver. The rat, on the other hand, has an efficient methylation of arsenic but the formed DMA is to a large extent accumulated in the red blood cells. As a result, the rat shows a low rate of excretion of arsenic. In both human subjects and rodents

Mobilization of soil-borne arsenic by three common organic acids: Dosage and time effects.

PubMed

Onireti, Olaronke O; Lin, Chuxia

2016-03-01

A batch experiment was conducted to investigate the mobilization of soil-borne arsenic by three common low-molecular-weight organic acids with a focus on dosage and time effects. The results show that oxalic acid behaved differently from citric acid and malic acid in terms of mobilizing As that was bound to iron compounds. At an equivalent molar concentration, reactions between oxalic acid and soil-borne Fe were kinetically more favourable, as compared to those between either citric acid or malic acid and the soil-borne Fe. It was found that reductive dissolution of soil-borne Fe played a more important role in liberating As, as compared to non-reductive reactions. Prior to the 7th day of the experiment, As mobility increased with increasing dose of oxalic acid while there was no significant difference (P > 0.05) in mobilized As among the treatments with different doses of citric acid or malic acid. The dosage effect on soil-borne As mobilization in the citric acid and malic acid treatments became clear only after the 7th day of the experiment. Soluble Ca present in the soils could cause re-immobilization of As by competing with solution-borne Fe for available organic ligands to form practically insoluble organic compounds of calcium (i.e. calcium oxalate). This resulted in transformation of highly soluble organic complexes of iron (i.e. iron oxalate complexes) into slightly soluble organic compounds of iron (i.e. iron oxalate) or free ferric ion, which then reacted with the solution-borne arsenate ions to form practically insoluble iron arsenates in the latter part of the experiment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Arsenic pollution sources.

PubMed

Garelick, Hemda; Jones, Huw; Dybowska, Agnieszka; Valsami-Jones, Eugenia

2008-01-01

Arsenic is a widely dispersed element in the Earth's crust and exists at an average concentration of approximately 5 mg/kg. There are many possible routes of human exposure to arsenic from both natural and anthropogenic sources. Arsenic occurs as a constituent in more than 200 minerals, although it primarily exists as arsenopyrite and as a constituent in several other sulfide minerals. The introduction of arsenic into drinking water can occur as a result of its natural geological presence in local bedrock. Arsenic-containing bedrock formations of this sort are known in Bangladesh, West Bengal (India), and regions of China, and many cases of endemic contamination by arsenic with serious consequences to human health are known from these areas. Significant natural contamination of surface waters and soil can arise when arsenic-rich geothermal fluids come into contact with surface waters. When humans are implicated in causing or exacerbating arsenic pollution, the cause can almost always be traced to mining or mining-related activities. Arsenic exists in many oxidation states, with arsenic (III) and (V) being the most common forms. Similar to many metalloids, the prevalence of particular species of arsenic depends greatly on the pH and redox conditions of the matrix in which it exists. Speciation is also important in determining the toxicity of arsenic. Arsenic minerals exist in the environment principally as sulfides, oxides, and phosphates. In igneous rocks, only those of volcanic origin are implicated in high aqueous arsenic concentrations. Sedimentary rocks tend not to bear high arsenic loads, and common matrices such as sands and sandstones contain lower concentrations owing to the dominance of quartz and feldspars. Groundwater contamination by arsenic arises from sources of arsenopyrite, base metal sulfides, realgar and orpiment, arsenic-rich pyrite, and iron oxyhydroxide. Mechanisms by which arsenic is released from minerals are varied and are accounted for by

Novel chitosan/PVA/zerovalent iron biopolymeric nanofibers with enhanced arsenic removal applications.

PubMed

Chauhan, Divya; Dwivedi, Jaya; Sankararamakrishnan, Nalini

2014-01-01

Enhanced removal application of both forms of inorganic arsenic from arsenic-contaminated aquifers at near-neutral pH was studied using a novel electrospun chitosan/PVA/zerovalent iron (CPZ) nanofibrous mat. CPZ was carefully examined using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), atomic fluorescence spectroscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). Application of the adsorbent towards the removal of total inorganic arsenic in batch mode has also been studied. A suitable mechanism for the adsorption has also been discussed. CPZ nanofibers mat was found capable to remove 200.0±10.0 mg g(-1) of As(V) and 142.9±7.2 mg g(-1) of As(III) from aqueous solution of pH 7.0 at ambient condition. Addition of ethylenediaminetetraacetic acid (EDTA) enabled the stability of iron in zerovalent state (ZVI). Enhanced capacity of the fibrous mat could be attributed to the high surface area of the fibers, presence of ZVI, and presence of functional groups such as amino, carboxyl, and hydroxyl groups of the chitosan and EDTA. Both Langmuir and Freundlich adsorption isotherms were applicable to describe the removal process. The possible mechanism of adsorption has been explained in terms of electrostatic attraction between the protonated amino groups of chitosan/arsenate ions and oxidation of arsenite to arsenate by Fentons generated from ZVI and subsequent complexation of the arsenate with the oxidized iron. These CPZ nanofibrous mats has been prepared with environmentally benign naturally occurring biodegradable biopolymer chitosan, which offers unique advantage in the removal of arsenic from contaminated groundwater.

Enhanced arsenic removal from water by hierarchically porous CeO₂-ZrO₂ nanospheres: role of surface- and structure-dependent properties.

PubMed

Xu, Weihong; Wang, Jing; Wang, Lei; Sheng, Guoping; Liu, Jinhuai; Yu, Hanqing; Huang, Xing-Jiu

2013-09-15

Arsenic contaminated natural water is commonly used as drinking water source in some districts of Asia. To meet the increasingly strict drinking water standards, exploration of efficient arsenic removal methods is highly desired. In this study, hierarchically porous CeO₂-ZrO₂ nanospheres were synthesized, and their suitability as arsenic sorbents was examined. The CeO₂-ZrO₂ hollow nanospheres showed an adsorption capacity of 27.1 and 9.2 mg g(-1) for As(V) and As(III), respectively, at an equilibrium arsenic concentration of 0.01 mg L(-1) (the standard for drinking water) under neutral conditions, indicating a high arsenic removal performance of the adsorbent at low arsenic concentrations. Such a great arsenic adsorption capacity was attributed to the high surface hydroxyl density and presence of hierarchically porous network in the hollow nanospheres. The analysis of Fourier transformed infrared spectra and X-ray photoelectron spectroscopy demonstrated that the adsorption of arsenic on the CeO₂-ZrO₂ nanospheres was completed through the formation of a surface complex by substituting hydroxyl with arsenic species. In addition, the CeO₂-ZrO₂ nanospheres were able to remove over 97% arsenic in real underground water with initial arsenic concentration of 0.376 mg L(-1) to meet the guideline limit of arsenic in drinking water regulated by the World Health Organization without any pre-treatment and/or pH adjustment. Copyright © 2013 Elsevier B.V. All rights reserved.

INFLUENCE OF AQUEOUS ALUMINUM AND ORGANIC ACIDS ON MEASUREMENT OF ACID NEUTRALIZING CAPACITY IN SURFACE WATERS

EPA Science Inventory

Acid neutralizing capacity (ANC) is used to quantify the acid-base status of surface waters. Acidic waters have bean defined as having ANC values less than zero, and acidification is often quantified by decreases in ANC. Measured and calculated values of ANC generally agree, exce...

Quantifying Inorganic Arsenic and Other Water-Soluble Arsenic Species in Human Milk by HPLC/ICPMS.

PubMed

Stiboller, Michael; Raber, Georg; Gjengedal, Elin Lovise Folven; Eggesbø, Merete; Francesconi, Kevin A

2017-06-06

Because the toxicity of arsenic depends on its chemical form, risk assessments of arsenic exposure must consider the type of arsenic compound, and hence they require sensitive and robust methods for their determination. Furthermore, the assessment should include studies on the most vulnerable people within a population, such as newborns and infants, and thus there is a need to quantify arsenic species in human milk. Herein we report a method for the determination of arsenic species at low concentrations in human milk by HPLC/ICPMS. Comparison of single and triple quadrupole mass analysers showed comparable performance, although the triple quadrupole instrument more efficiently overcame the problem of ArCl + interference, from the natural chloride present in milk, without the need for gradient elution HPLC conditions. The method incorporates a protein precipitation step with trifluoroacetic acid followed by addition of dichloromethane or dibromomethane to remove the lipids. The aqueous phase was subjected to anion-exchange and cation-exchange/mixed mode chromatography with aqueous ammonium bicarbonate and pyridine buffer solutions as mobile phases, respectively. For method validation, a human milk sample was spiked with defined amounts of dimethylarsinate, arsenobetaine, and arsenate. The method showed good recoveries (99-103%) with detection limits (in milk) in the range of 10 ng As kg -1 . The method was further tested by analyzing two Norwegian human milk samples where arsenobetaine, dimethylarsinate, and a currently unknown As species were found, but iAs was not detected.

Biogenic arsenic volatilisation from an acidic wetland soil

NASA Astrophysics Data System (ADS)

Ilgen, Gunter; Huang, Jen-How; Lu, Shipeng; Tian, Liyan; Alewell, Christine

2014-05-01

Biogenic arsenic (As) volatilisation was budgeted at 26000 t yr-1as the largest input of the global As release into the atmosphere, thereby playing an important role in the biogeochemical cycle of As in the surface environment. In order to quantify As volatilisation from wetland soils and to elucidate the geochemical and microbiological factors governing As volatilisation, a series of incubations with an acidic wetland soil collected in NE-Bavaria in Germany were performed at 15oC for 4 months with addition of NaN3, arsenite (As(III)), FeCl3, NaSO4 and NaOAc with N2 and air in the headspace. Speciation of gaseous As in the headspace using GC-ICP-MS/ ESI-MS coupling showed the predominance of either arsine (AsH3) or trimethylarsine ((CH3)3As) in all treatments during the time course of incubation. Monomethylarsine ((CH3)AsH2) and dimethylarsine ((CH3)2AsH) could be only detected in trace amounts. Arsenic speciation in porewater with HPLC-ICP-MS revealed the predominance of As(III) and methylated As was never detectable. Arsenic volatilisation summed to 2.3 ng As (88% as AsH3) in the control incubations, which accounted for ~0.25 % of the total As storage in the wetland soil. Treatments with 10 mM NaN3 resulted in emission of only 0.03 ng As. In contrast, addition of 10 mM NaOAc stimulated microbial activities in wetland soils and subsequently rose As volatilisation to 8.5 ng As. It could be therefore concluded that As volatilisation from the wetland soils was mainly biological. Spiking 67 μM As(III) increased 10 times of As volatilisation and the proportion of methylated arsines increased to 66%, which is supposed to be caused by the largely enhanced As availability in porewater for microbes (480 ppb, ~65 times higher than those in the controls). Adding 10 mM FeCl3 stimulated microbial Fe(III) reducing activities but suppressed other microbial activities by lowering soil pH from 5 to 3.6, decreasing consequently As volatilisation to 0.3 ng As. The much lower redox

Automated atomic absorption spectrometric determination of total arsenic in water and streambed materials

USGS Publications Warehouse

Fishman, M.

1977-01-01

An automated method to determine both inorganic and organic forms of arsenic In water, water-suspended mixtures, and streambed materials Is described. Organic arsenic-containing compounds are decomposed by either ultraviolet radiation or by suHurlc acid-potassium persulfate digestion. The arsenic liberated, with Inorganic arsenic originally present, is reduced to arsine with sodium borohydrlde. The arable Is stripped from the solution with the aid of nitrogen and Is then decomposed In a tube furnace heated to 800 ??C which Is placed in the optical path of an atomic absorption spectrometer. Thirty samples per hour can be analyzed to levels of 1 ??g arsenic per liter.

Accumulation features of arsenic species in various fishes collected from coastal cities in Korea

NASA Astrophysics Data System (ADS)

Choi, Sung-Deuk; Son, Hee-Sik; Choi, Minkyu; Park, Min-Kyu

2015-12-01

In this study, 36 fish species were collected from three coastal cities in Korea to investigate levels and patterns of six arsenicals (arsenite: As (III), arsenate: As (V), arsenocholine: AsC, arsenobetaine: AsB, monomethylarsonic acid: MMA, and dimethylarsinic acid: DMA). The levels of ∑6 As in the different fish species varied substantially, ranging from 0.02 μg As/g ww (Islaeli carp) to 9.65 μg As/g ww (Skate ray) with a median of 0.40 μg As/g ww. All the arsenicals in marine fishes showed higher levels than those in freshwater fishes due to fish feed living in saline water. Overall, marine carnivorous fishes seem to be more contaminated with arsenic. For all the fish samples, AsB (mean fraction: 90.6%) was dominant among the six arsenicals, indicating biomethylation of inorganic arsenic and accumulation of AsB. Fish species with high water contents showed elevated levels of As (III), but there was no further significant correlations between arsenicals and water/lipid contents. Concentrations of As (V) were significantly lower than those of As (III), which implies that As (V) is reduced during biomethylation of inorganic arsenic. Consequently, we hypothesize that the toxicity of arsenic (mainly derived from As (III)) can be increased by the reduction of As (V), especially for the fish species with higher water contents.

Arsenic Accumulation by Pteris vittata L. in Two Chemically Variant Soils Treated with Arsenical Pesticides - Greenhouse Study

NASA Astrophysics Data System (ADS)

Therapong, C.; Datta, R.; Sarkar, D.; Pachanoor, D.

2006-05-01

Arsenic (As) is one of the most toxic elements present in the environment. Over the years, arsenic has found its way to the environment due to its extensive use in agriculture and in industrial practices as pesticides, fertilizers, wood preservatives, smelter wastes and coal combustion ash, all of which are of great environmental concern. Arsenic contamination affects biological activities because it is a carcinogen and a mutagen, which has detrimental effects on the immune system of animals. Remediation of arsenic-contaminated soils has become a major environmental issue in the recent years. Several physical and chemical treatment methods, such as soil washing, co-precipitation, and excavation, have used to remediate As, but all of these methods are rather expensive and can disturb soil physiology and ecology. Phytoremediation, a plant based technology for the removal of toxic contaminants from soil and water is an attractive approach. Of late, this technology has received a high degree of attention from the scientific community because it is environment-friendly and also because of its tremendous cost efficiency compared to the conventional methods. Chinese Brake Fern (Pteris vittata L.) is a known arsenic hyperaccumulator that is being used extensively at present to remove As from soils. However, the degree of efficiency of this plant in accumulating As is likely to be a function of the soil properties. The objective of the reported study was to investigate arsenic uptake by Chinese Brake Fern in As-contaminated soils from the Immokalee (acid sand with minimal As-retention potential) and Millhopper series (sandy loam with high Fe/Al content, hence, high As-retention potential). A greenhouse experiment was designed to evaluate the effects on As uptake by Chinese Brake Fern at two pesticide application rates: 225 mg/kg and 500 mg/kg As in two chemical forms, namely sodium arsenate (AsV) and dimethylarsinic acid (DMA). Each treatment was replicated three times in

Arsenic Exposure in Relation to Ischemic Stroke: The Reasons for Geographic and Racial Differences in Stroke Study.

PubMed

Tsinovoi, Cari L; Xun, Pengcheng; McClure, Leslie A; Carioni, Vivian M O; Brockman, John D; Cai, Jianwen; Guallar, Eliseo; Cushman, Mary; Unverzagt, Frederick W; Howard, Virginia J; He, Ka

2018-01-01

The purpose of this case-cohort study was to examine urinary arsenic levels in relation to incident ischemic stroke in the United States. We performed a case-cohort study nested within the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort. A subcohort (n=2486) of controls was randomly sampled within region-race-sex strata while all incident ischemic stroke cases from the full REGARDS cohort (n=671) were included. Baseline urinary arsenic was measured by inductively coupled plasma-mass spectrometry. Arsenic species, including urinary inorganic arsenic and its metabolites monomethylarsonic acid and dimethylarsinic acid, were measured in a random subset (n=199). Weighted Cox's proportional hazards models were used to calculate hazard ratios and 95% confidence intervals of ischemic stroke by arsenic and its species. The average follow-up was 6.7 years. Although incident ischemic stroke showed no association with total arsenic or total inorganic arsenic, for each unit higher level of urinary monomethylarsonic acid on a log-scale, after adjustment for potential confounders, ischemic stroke risk increased ≈2-fold (hazard ratio=1.98; 95% confidence interval: 1.12-3.50). Effect modification by age, race, sex, or geographic region was not evident. A metabolite of arsenic was positively associated with incident ischemic stroke in this case-cohort study of the US general population, a low-to-moderate exposure area. Overall, these findings suggest a potential role for arsenic methylation in the pathogenesis of stroke, having important implications for future cerebrovascular research. © 2017 American Heart Association, Inc.

Rapid degradation of p-arsanilic acid with simultaneous arsenic removal from aqueous solution using Fenton process.

PubMed

Xie, Xiande; Hu, Yuanan; Cheng, Hefa

2016-02-01

Although banned in some developed countries, p-arsanilic acid (p-ASA) is still used widely as a feed additive for swine production in many countries. With little uptake and transformation in animal bodies, nearly all the p-ASA administered to animals is excreted chemically unchanged in animal wastes, which can subsequently release the more toxic inorganic arsenic species upon degradation in the environment. For safe disposal of the animal wastes laden with p-ASA, we proposed a method of leaching the highly water-soluble p-ASA out of the manure first, followed by treatment of the leachate using the Fenton process to achieve fast oxidation of p-ASA and removal of the inorganic arsenic species released (predominantly arsenate) from solution simultaneously. The effects of solution pH, dosages of H2O2 and Fe(2+), and the presence of dissolved organic matter (DOM) on the treatment efficiency were systematically investigated. Under the optimum treatment conditions (0.53 mmol L(-1) Fe(2+), 2.12 mmol L(-1) H2O2, and initial pH of 3.0), p-ASA (10 mg-As L(-1)) could be completely oxidized to As(V) within 30 min in pure water and 4 natural water samples, and at the final pH of 4.0, the residual arsenic levels in solution phase were as low as 1.1 and 20.1-43.4 μg L(-1) in the two types of water matrixes, respectively. The presence of humic acid significantly retarded the oxidation of p-ASA by scavenging HO, and inhibited the As(V) removal through competitive adsorption on ferric hydroxide. Due to the high contents of DOM in the swine manure leachate samples (TOC at ∼500 mg L(-1)), much higher dosages of Fe(2+) (10.0 mmol L(-1)) and H2O2 (40.0 mmol L(-1)) and a longer treatment time (120 min) were required to achieve near complete oxidation of p-ASA (98.0%), while maintaining the levels of residual arsenic in the solution at <70.0 μg L(-1). The degradation pathway of p-ASA in the Fenton process was proposed based on the major degradation products detected

Fe-FeS2 adsorbent prepared with iron powder and pyrite by facile ball milling and its application for arsenic removal.

PubMed

Min, Xiaobo; Li, Yangwenjun; Ke, Yong; Shi, Meiqing; Chai, Liyuan; Xue, Ke

2017-07-01

Arsenic is one of the major pollutants and a worldwide concern because of its toxicity and chronic effects on human health. An adsorbent of Fe-FeS 2 mixture for effective arsenic removal was successfully prepared by mechanical ball milling. The products before and after arsenic adsorption were characterized with scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The adsorbent shows high arsenic removal efficiency when molar ratio of iron to pyrite is 5:5. The experimental data of As(III) adsorption are fitted well with the Langmuir isotherm model with a maximal adsorption capacity of 101.123 mg/g. And As(V) data were described perfectly by the Freundlich model with a maximal adsorption capacity of 58.341 L/mg. As(III) is partial oxidized to As(V) during the adsorption process. High arsenic uptake capability and cost-effectiveness of waste make it potentially attractive for arsenic removal.

Uptake of aromatic arsenicals from soil contaminated with diphenylarsinic acid by rice.

PubMed

Arao, Tomohito; Maejima, Yuji; Baba, Koji

2009-02-15

Chemical warfare agents containing aromatic arsenicals (AAs) such as Clark I (diphenylchloroarsine) are well-known, as is the risk of leakage from such munitions into the environment. We investigated the uptake of AAs in agricultural soils by rice. Methylphenylarsinic acid (MPAA) was detected in brown rice grown in contaminated soil. Dimethylphenylarsine oxide (DMPAO) and methyldiphenylarsine oxide (MDPAO) were detected in the straw but not in the grains grown in the contaminated soil. Inthe contaminated soil, phenylarsonic acid (PAA) and MPAA concentrations decreased and DMPAO concentration increased under the flooded conditions; however, their concentrations remained unchanged underthe upland conditions. DMPAO was detected in the straw of the rice grown in PAA- or MPAA-amended soil but was not detected in that grown in a PAA- or MPAA-added solution culture. MDPAO was detected in the straw of the rice grown in diphenylarsinic acid (DPAA)-amended soil but was not detected in that grown in a DPAA-added solution culture. Thus, MPAA and DPAA were methylated not in the rice plant but in the soil under the flooded conditions. Dephenylated products were detected in the straw grown in AA-added solution cultures, but demethylated products were not detected. DMPAO and MDPAO absorbed by the shoots were retained, and MPAA and DPAA absorbed by the shoots were translocated to the grains more easily than other AAs.

Seasonal arsenic accumulation in stream sediments at a groundwater discharge zone.

PubMed

MacKay, Allison A; Gan, Ping; Yu, Ran; Smets, Barth F

2014-01-21

Seasonal changes in arsenic and iron accumulation rates were examined in the sediments of a brook that receives groundwater discharges of arsenic and reduced iron. Clean glass bead columns were deployed in sediments for known periods over the annual hydrologic cycle to monitor changes in arsenic and iron concentrations in bead coatings. The highest accumulation rates occurred during the dry summer period (July-October) when groundwater discharges were likely greatest at the sample locations. The intermediate flow period (October-March), with higher surface water levels, was associated with losses of arsenic and iron from bead column coatings at depths below 2-6 cm. Batch incubations indicated iron releases from solids to be induced by biological reduction of iron (oxy)hydroxide solids. Congruent arsenic releases during incubation were limited by the high arsenic sorption capacity (0.536 mg(As)/mg(Fe)) of unreacted iron oxide solids. The flooded spring (March-June) with high surface water flows showed the lowest arsenic and iron accumulation rates in the sediments. Comparisons of accumulation rates across a shoreline transect were consistent with greater rates at regions exposed above surface water levels for longer times and greater losses at locations submerged below surface water. Iron (oxy)hydroxide solids in the shallowest sediments likely serve as a passive barrier to sorb arsenic released to pore water at depth by biological iron reduction.

Metabolism and toxicity of arsenicals in mammals.

PubMed

Sattar, Adeel; Xie, Shuyu; Hafeez, Mian Abdul; Wang, Xu; Hussain, Hafiz Iftikhar; Iqbal, Zahid; Pan, Yuanhu; Iqbal, Mujahid; Shabbir, Muhammad Abubakr; Yuan, Zonghui

2016-12-01

Arsenic (As) is a metalloid usually found in organic and inorganic forms with different oxidation states, while inorganic form (arsenite As-III and arsenate As-v) is considered to be more hazardous as compared to organic form (methylarsonate and dimethylarsinate), with mild or no toxicity in mammals. Due to an increasing trend to using arsenicals as growth promoters or for treatment purposes, the understanding of metabolism and toxicity of As gets vital importance. Its toxicity is mainly depends on oxi-reduction states (As-III or As-v) and the level of methylation during the metabolism process. Currently, the exact metabolic pathways of As have yet to be confirmed in humans and food producing animals. Oxidative methylation and glutathione conjugation is believed to be major pathways of As metabolism. Oxidative methylation is based on conversion of Arsenite in to mono-methylarsonic acid and di-methylarsenic acid in mammals. It has been confirmed that As is only methylated in the presence of glutathione or thiol compounds, suggesting that As is being methylated in trivalent states. Subsequently, non-conjugated trivalent arsenicals are highly reactive with thiol which converts the trivalent arsenicals in to less toxic pentavalent forms. The glutathione conjugate stability of As is the most important factor for determining the toxicity. It can lead to DNA damage by alerting enzyme profile and production of reactive oxygen and nitrogen species which causes the oxidative stress. Moreover, As causes immune-dysfunction by hindering cellular and humeral immune response. The present review discussed different metabolic pathways and toxic outcomes of arsenicals in mammals which will be helpful in health risk assessment and its impact on biological world. Copyright © 2016. Published by Elsevier B.V.

Arsenic (+3 Oxidation State) Methyltransferase and the Methylation of Arsenicals

PubMed Central

Thomas, David J.; Li, Jiaxin; Waters, Stephen B.; Xing, Weibing; Adair, Blakely M.; Drobna, Zuzana; Devesa, Vicenta; Styblo, Miroslav

2008-01-01

Metabolic conversion of inorganic arsenic into methylated products is a multistep process that yields mono-, di-, and trimethylated arsenicals. In recent years, it has become apparent that formation of methylated metabolites of inorganic arsenic is not necessarily a detoxification process. Intermediates and products formed in this pathway may be more reactive and toxic than inorganic arsenic. Like all metabolic pathways, understanding the pathway for arsenic methylation involves identification of each individual step in the process and the characterization of the molecules which participate in each step. Among several arsenic methyltransferases that have been identified, arsenic (+3 oxidation state) methyltransferase is the one best characterized at the genetic and functional levels. This review focuses on phylogenetic relationships in the deuterostomal lineage for this enzyme and on the relation between genotype for arsenic (+3 oxidation state) methyltransferase and phenotype for conversion of inorganic arsenic to methylated metabolites. Two conceptual models for function of arsenic (+3 oxidation state) methyltransferase which posit different roles for cellular reductants in the conversion of inorganic arsenic to methylated metabolites are compared. Although each model accurately represents some aspects of enzyme’s role in the pathway for arsenic methylation, neither model is a fully satisfactory representation of all the steps in this metabolic pathway. Additional information on the structure and function of the enzyme will be needed to develop a more comprehensive model for this pathway. PMID:17202581

Effects of endogenous hydrogen peroxide and glutathione on the stability of arsenic metabolites in rat bile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobayashi, Yayoi; Hirano, Seishiro

2008-10-01

Trivalent arsenicals such as arsenite (iAs{sup III}), monomethylarsonous acid (MMA{sup III}) and dimethylarsinous acid (DMA{sup III}) are more toxic than analogous pentavalent compounds such as arsenate (iAs{sup V}), monomethylarsonic acid (MMA{sup V}) and dimethylarsinic acid (DMA{sup V}). It has been reported that arsenic-glutathione (As-GSH) complexes such as arsenic triglutathione (ATG) and methylarsenic diglutathione (MADG) are major metabolites in rat bile following intravenous administration of iAs{sup III}. Recently, we have shown that both ATG and MADG are unstable and easily hydrolyzed to iAs{sup III} and MMA{sup III}, respectively, and that MMA{sup III} is oxidized to MMA{sup V} in bile. In themore » present study we report the effects of H{sub 2}O{sub 2} and GSH on the stability of As-GSH complexes in rat bile. Male SD rats were injected intravenously with saline or iAs{sup III} at a dose of 0.2 or 2.0 mg As/kg body weight, and bile fluid was collected on ice for 30 min. To estimate the stability of As-GSH complexes in bile, ATG or MADG was added to untreated, heat-treated, catalase-treated, or dialyzed bile, and then incubated at 37 deg. C for 10 min. Concentrations of biliary H{sub 2}O{sub 2} and GSH in the higher dose group were 12.6- and 4.5-times higher than the control value, respectively. Exogenously added trivalent arsenicals were oxidized to pentavalent arsenicals in the bile depending on the biliary concentration of H{sub 2}O{sub 2}. Both catalase and dialysis prevented oxidation of trivalent arsenicals to the corresponding pentavalent compounds. Exogenously added GSH stabilized As-GSH complexes in bile. These results suggest that H{sub 2}O{sub 2} converts trivalent arsenicals to less toxic pentavalent arsenicals, whereas GSH prevents hydrolysis of As-GSH complexes and the generation of unconjugated toxic trivalent arsenicals.« less

Characterization of arsenite-oxidizing bacteria to decipher their role in arsenic bioremediation.

PubMed

Biswas, Rimi; Sarkar, Angana

2018-06-11

High arsenic groundwater contamination causes serious health risks in many developing countries, particularly in India and Bangladesh. The arsenic fluxes in aquifers are primarily controlled by bacterial populations through biogeochemical cycle. In this present study, two gram-positive rod-shaped bacteria were isolated from shallow aquifers of Bhojpur district in Bihar during the early winter season, able to withstand arsenite (As 3+ ) concentration upto 70 mM and 1000 mM of arsenate (As 5+ ) concentration. They showed high resistance to heavy metals up to 30 mM and utilized some complex sugars along with different carbon sources. Growth at wide range of temperature, pH and salinity were observed. Both these isolates showed high efficiency in converting As 3+ into less toxic concentrations of As 5+ respectively from arsenic enriched culture media. Along with superior arsenic transformation and arsenic resistance abilities, the isolates showed a wide variety of metabolic capacity in terms of utilizing a variety of carbon sources under aerobic conditions, respectively. This study reports the potential As 3+ -oxidizing bacteria that can play an important role in subsurface arsenic transformation that will aid in designing future bioremediation strategy for the arsenic affected areas.

Proteomic profiling reveals candidate markers for arsenic-induced skin keratosis.

PubMed

Guo, Zhiling; Hu, Qin; Tian, Jijing; Yan, Li; Jing, Chuanyong; Xie, Heidi Qunhui; Bao, Wenjun; Rice, Robert H; Zhao, Bin; Jiang, Guibin

2016-11-01

Proteomics technology is an attractive biomarker candidate discovery tool that can be applied to study large sets of biological molecules. To identify novel biomarkers and molecular targets in arsenic-induced skin lesions, we have determined the protein profile of arsenic-affected human epidermal stratum corneum by shotgun proteomics. Samples of palm and foot sole from healthy subjects were analyzed, demonstrating similar protein patterns in palm and sole. Samples were collected from the palms of subjects with arsenic keratosis (lesional and adjacent non-lesional samples) and arsenic-exposed subjects without lesions (normal). Samples from non-exposed healthy individuals served as controls. We found that three proteins in arsenic-exposed lesional epidermis were consistently distinguishably expressed from the unaffected epidermis. One of these proteins, the cadherin-like transmembrane glycoprotein, desmoglein 1 (DSG1) was suppressed. Down-regulation of DSG1 may lead to reduced cell-cell adhesion, resulting in abnormal epidermal differentiation. The expression of keratin 6c (KRT6C) and fatty acid binding protein 5 (FABP5) were significantly increased. FABP5 is an intracellular lipid chaperone that plays an essential role in fatty acid metabolism in human skin. This raises a possibility that overexpression of FABP5 may affect the proliferation or differentiation of keratinocytes by altering lipid metabolism. KRT6C is a constituent of the cytoskeleton that maintains epidermal integrity and cohesion. Abnormal expression of KRT6C may affect its structural role in the epidermis. Our findings suggest an important approach for future studies of arsenic-mediated toxicity and skin cancer, where certain proteins may represent useful biomarkers of early diagnoses in high-risk populations and hopefully new treatment targets. Further studies are required to understand the biological role of these markers in skin pathogenesis from arsenic exposure. Copyright © 2016 Elsevier Ltd

Arsenic-Based Drugs: From Fowler's Solution to Modern Anticancer Chemotherapy

NASA Astrophysics Data System (ADS)

Gibaud, Stéphane; Jaouen, Gérard

Although arsenic is a poison and has a predominantly unfavorable reputation, it has been used as pharmaceutical agent since the first century BC. In 1786, Thomas Fowler reported the effects of arsenic in the cure of agues, remittent fevers, and periodic headaches. From this time on and despite abusive use, some interesting indications began to appear for trypanosomiasis, syphilis, and blood diseases. The first significant organoarsenical drug (atoxyl) was synthesized by Pierre Antoine Béchamp in 1859 by chemically reacting arsenic acid with aniline but additional experimentations on the properties of arsenic led Paul Ehrlich, the founder of chemotherapy, to the discovery of salvarsan in 1910. From the Second World War, Ernst A.H. Friedheim greatly improved the treatment of trypanosomiasis by melaminophenyl arsenicals. Until the 1990s some organoarsenicals were used for intestinal parasite infections but carcinogenic effects were displayed and all the drugs have been withdrawn in USA, in Europe, and elsewhere. In 2003, arsenic trioxide (Trisenox®) was re-introduced for the treatment of very specific hematological malignancies.

Predicting arsenic bioavailability to hyperaccumulator Pteris vittata in arsenic-contaminated soils.

PubMed

Gonzaga, Maria Isidória Silva; Ma, Lena Q; Pacheco, Edson Patto; dos Santos, Wallace Melo

2012-12-01

Using chemical extraction to evaluate plant arsenic availability in contaminated soils is important to estimate the time frame for site cleanup during phytoremediation. It is also of great value to assess As mobility in soil and its risk in environmental contamination. In this study, four conventional chemical extraction methods (water, ammonium sulfate, ammonium phosphate, and Mehlich III) and a new root-exudate based method were used to evaluate As extractability and to correlate it with As accumulation in P. vittata growing in five As-contaminated soils under greenhouse condition. The relationship between different soil properties, and As extractability and plant As accumulation was also investigated. Arsenic extractability was 4.6%, 7.0%, 18%, 21%, and 46% for water, ammonium sulfate, organic acids, ammonium phosphate, and Mehlich III, respectively. Root exudate (organic acids) solution was suitable for assessing As bioavailability (81%) in the soils while Mehlich III (31%) overestimated the amount of As taken up by plants. Soil organic matter, P and Mg concentrations were positively correlated to plant As accumulation whereas Ca concentration was negatively correlated. Further investigation is needed on the effect of Ca and Mg on As uptake by P. vittata. Moreover, additional As contaminated soils with different properties should be tested.

Uric acid and serum antioxidant capacity: a reaction to atherosclerosis?

PubMed

Nieto, F J; Iribarren, C; Gross, M D; Comstock, G W; Cutler, R G

2000-01-01

the evidence of a potential beneficial role of antioxidants in preventing atherosclerotic disease is not entirely consistent. to assess the longitudinal association of serum total antioxidant capacity and serum antioxidants with the presence of subclinical carotid atherosclerosis. Prospective case-control study nested within an historical cohort. Cases were 150 individuals with elevated carotid intimal-medial thickness measured by B-mode ultrasound at the first two examinations of the Atherosclerosis Risk in Communities Study (1987-92). Controls were 150 age-gender-matched individuals with low carotid intimal-medial thickness. Serum antioxidant vitamins, uric acid, and serum total antioxidant capacity were measured in frozen serum samples collected from the same individuals in 1974 (13-15 years prior to the determination of case-control status). Compared to controls, atherosclerosis cases had significantly higher levels of serum total antioxidant capacity in 1974 than controls. This difference was almost entirely explained by increased serum concentration of uric acid in cases. In contrast with cross-sectional results, uric acid serum concentration in 1974, was significantly higher in cases than in controls, even after adjusting for the main cardiovascular risk factors. Cases had significantly lower levels of alpha-carotene in the 1974 sera than controls, but no other differences in serum antioxidant vitamin concentrations were observed. The higher serum uric acid concentration seemed associated with elevated total serum antioxidant capacity among individuals with atherosclerosis. This finding is consistent with experimental evidence suggesting that hyperuricemia may be a compensatory mechanism to counteract oxidative damage related to atherosclerosis and aging in humans.

Mobility and natural attenuation of metals and arsenic in acidic waters of the drainage system of Timok River from Bor copper mines (Serbia) to Danube River.

PubMed

Đorđievski, Stefan; Ishiyama, Daizo; Ogawa, Yasumasa; Stevanović, Zoran

2018-06-22

Bor, Krivelj, and Bela Rivers belong to the watershed of Timok River, which is a tributary of transboundary Danube River. These rivers receive metal-rich acidic wastewater from metallurgical facilities and acid mine drainage (AMD) from mine wastes around Bor copper mines. The aim of this study was to determine the mobility and natural attenuation of metals and arsenic in rivers from Bor copper mines to Danube River during the year 2015. The results showed that metallurgical facilities had the largest impact on Bor River by discharging about 400 t of Cu per year through highly acidic wastewater (pH = 2.6). The highest measured concentrations of Cu in river water and sediments were 40 mg L -1 and 1.6%, respectively. Dissolution of calcite from limestone bedrock and a high concentration of bicarbonate ions in natural river water (about 250 mg L -1 ) enhanced the neutralization of acidic river water and subsequent chemical precipitation of metals and arsenic. Decreases in the concentrations of Al, Fe, Cu, As, and Pb in river water were mainly due to precipitation on the river bed. On the other hand, dilution played an important role in the decreases in concentrations of Mn, Ni, Zn, and Cd. Chemically precipitated materials and flotation tailings containing Fe-rich minerals (fayalite, magnetite, and pyrite) were transported toward Danube River during the periods of high discharge. This study showed that processes of natural attenuation in catchments with limestone bedrock play an important role in reducing concentrations of metals and arsenic in AMD-bearing river water.

Arsenic Exposure through Drinking Water Is Associated with Longer Telomeres in Peripheral Blood

PubMed Central

2012-01-01

Inorganic arsenic is a strong carcinogen, possibly by interaction with the telomere length. The aim of the study was to evaluate how chronic arsenic exposure from drinking water as well as the arsenic metabolism efficiency affect the individual telomere length and the expression of telomere-related genes. Two hundred two women with a wide range in exposure to arsenic via drinking water (3.5–200 μg/L) were recruited. Concentrations of arsenic metabolites in urine [inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA)] were measured. The relative telomere length in blood was measured by quantitative real-time polymerase chain reaction. Genotyping (N = 172) for eight SNPs in AS3MT and gene expression of telomere-related genes (in blood; N = 90) were performed. Urinary arsenic (sum of metabolites) was positively associated with telomere length (β = 0.65 × 10–4, 95% CI = 0.031 × 10–4–1.3 × 10–4, adjusted for age and BMI). Individuals with above median fractions of iAs and MMA showed significantly longer telomeres by increasing urinary arsenic (β = 1.0 × 10–4, 95% CI = 0.21 × 10–4–1.8 × 10–4 at high % iAs; β = 0.88 × 10–4 95% CI = 0.12 × 10–4–1.6 × 10–4 at high % MMA) than those below the median (p = 0.80 and 0.44, respectively). Similarly, carriers of the slow and more toxic metabolizing AS3MT haplotype showed stronger positive associations between arsenic exposure and telomere length, as compared to noncarriers (interaction urinary arsenic and haplotype p = 0.025). Urinary arsenic was positively correlated with the expression of telomerase reverse transcriptase (TERT, Spearman r = 0.22, p = 0.037), but no association was found between TERT expression and telomere length. Arsenic in drinking water influences the telomere length, and this may be a mechanism for its carcinogenicity. A faster and less toxic arsenic metabolism diminishes arsenic-related telomere elongation. PMID:22917110

Omega-3 and omega-6 polyunsaturated fatty acids enhance arsenic trioxide efficacy in arsenic trioxide-resistant leukemic and solid tumor cells.

PubMed

Wirtitsch, Melanie; Roth, Erich; Bachleitner-Hofmann, Thomas; Wessner, Barbara; Sturlan, Sanda

2009-01-01

Recently we showed that the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) sensitizes arsenic trioxide (As2O3)-resistant tumor cells to a clinically achievable concentration (1 microM) of As2O3 via a reactive oxygen species (ROS)-dependent mechanism. The aim of the present study was to evaluate, whether this combined effect of As2O3 and DHA is also applicable to other PUFAs [i.e., eicospentaenoic acid (EPA), arachidonic acid (AA), and gamma-linolenic acid (GLA)]. Fourteen tumor cell lines were incubated with As2O3 (1 microM), PUFA (25-100 microM), or the combination thereof (+/- vitamin E). Cell viability (colorimetric), apoptosis (bivariate annexin V/propidium iodide staining, detection of hypodiploid DNA), and thiobarbituric acid reactive substances (TBARS) were evaluated. Twelve of 14 As2O3-resistant cell lines tested were resistant to PUFA monotherapy. However, combined treatment with As2O3 and either PUFA significantly reduced cell viability in a dose-dependent manner with AA being the most potent As2O3 enhancer. The combined cytotoxic effect of As2O3/AA treatment was due to induction of apoptosis, preceded by increased intracellular TBARS and was abolished by the antioxidant vitamin E. Importantly, the combined effect of As2O3 and AA was selectively toxic for malignant cells because no cytotoxic effect was observed in normal skin fibroblasts and human microvascular endothelial cells. In conclusion, our study shows that also other PUFAs than DHA-and in particular the omega-6-PUFA AA--can be used as effective modulators of tumor cell chemosensitivity to clinically achievable concentrations of As2O3. Enhanced lipid peroxidation most likely constitutes the key mechanism for the combined effect.

Total and inorganic arsenic in dietary supplement supplies in northern Mexico.

PubMed

García-Rico, Leticia; Tejeda-Valenzuela, Lourdes

2013-07-01

The aim of this study was to evaluate the presence of total and inorganic arsenic in dietary supplements composed of herbal plants and seaweed, and to determine the potential toxicological risk. Total arsenic was determined by dry ashing and hydride generation atomic absorption spectrometry, and inorganic arsenic was determined by acid digestion, solvent extraction, and hydride generation atomic absorption spectrometry. Total and inorganic arsenic in the supplements ranged from 0.07 to 8.31 mg kg(-1) dry weight and from 0.14 to 0.28 mg kg(-1) dry weight, respectively. Daily intake of total arsenic ranged from 0.05 to 12.46 μg day(-1). Inorganic arsenic intake ranged from 0.21 to 0.83 μg day(-1), values that are below the Benchmark Dose Lower Confidence Limit recommended by the Word Health Organization. Therefore, there appears to be a low risk of adverse effects resulting from excess inorganic arsenic intake from these supplements. This is the first study conducted in Mexico that investigates total and inorganic arsenic in dietary supplements. Although the results do not suggest toxicological risk, it is nonetheless important considering the toxicity of inorganic arsenic and the increasing number consumer preferences for dietary supplements. Moreover, it is important to improve and ensure the safety of dietary supplements containing inorganic arsenic.

Strategies for the engineered phytoremediation of toxic element pollution: mercury and arsenic.

PubMed

Meagher, Richard B; Heaton, Andrew C P

2005-12-01

xylem up to leaves, and efficient xylem unloading aboveground. These systems can be enhanced for the movement of arsenic and mercury. (6) Aboveground control over the electrochemical state and chemical speciation of elemental pollutants will maximize their storage in leaves, stems, and vascular tissues. Our research suggests ionic Hg(II) and arsenite will be the best chemical species to trap aboveground. (7) Chemical sinks can increase the storage capacity for essential nutrients like iron, zinc, copper, sulfate, and phosphate. Organic acids and thiol-rich chelators are among the important chemical sinks that could trap maximal levels of mercury and arsenic aboveground. (8) Physical sinks such as subcellular vacuoles, epidermal trichome cells, and dead vascular elements have shown the evolutionary capacity to store large quantities of a few toxic pollutants aboveground in various native hyperaccumulators. Specific plant transporters may already recognize gluthione conjugates of Hg(II) or arsenite and pump them into vacuole.

From an old remedy to a magic bullet: molecular mechanisms underlying the therapeutic effects of arsenic in fighting leukemia

PubMed Central

Zhou, Guang-Biao; Zhang, Xiao-Wei; Mao, Jian-Hua; de Thé, Hugues

2011-01-01

Arsenic had been used in treating malignancies from the 18th to mid-20th century. In the past 3 decades, arsenic was revived and shown to be able to induce complete remission and to achieve, when combined with all-trans retinoic acid and chemotherapy, a 5-year overall survival of 90% in patients with acute promyelocytic leukemia driven by the t(15;17) translocation-generated promyelocytic leukemia–retinoic acid receptor α (PML-RARα) fusion. Molecularly, arsenic binds thiol residues and induces the formation of reactive oxygen species, thus affecting numerous signaling pathways. Interestingly, arsenic directly binds the C3HC4 zinc finger motif in the RBCC domain of PML and PML-RARα, induces their homodimerization and multimerization, and enhances their interaction with the SUMO E2 conjugase Ubc9, facilitating subsequent sumoylation/ubiquitination and proteasomal degradation. Arsenic-caused intermolecular disulfide formation in PML also contributes to PML-multimerization. All-trans retinoic acid, which targets PML-RARα for degradation through its RARα moiety, synergizes with arsenic in eliminating leukemia-initiating cells. Arsenic perturbs a number of proteins involved in other hematologic malignancies, including chronic myeloid leukemia and adult T-cell leukemia/lymphoma, whereby it may bring new therapeutic benefits. The successful revival of arsenic in acute promyelocytic leukemia, together with modern mechanistic studies, has thus allowed a new paradigm to emerge in translational medicine. PMID:21422471

Enhanced removal of arsenic from a highly laden industrial effluent using a combined coprecipitation/nano-adsorption process.

PubMed

Jiang, Yingnan; Hua, Ming; Wu, Bian; Ma, Hongrui; Pan, Bingcai; Zhang, Quanxing

2014-05-01

Effective arsenic removal from highly laden industrial wastewater is an important but challenging task. Here, a combined coprecipitation/nano-adsorption process, with ferric chloride and calcium chloride as coprecipitation agents and polymer-based nanocomposite as selective adsorbent, has been validated for arsenic removal from tungsten-smelting wastewater. On the basis of operating optimization, a binary FeCl3 (520 mg/L)-CaCl2 (300 mg/L) coprecipitation agent could remove more than 93% arsenic from the wastewater. The resulting precipitate has proved environmental safety based on leaching toxicity test. Fixed-bed column packed with zirconium or ferric-oxide-loaded nanocomposite was employed for further elimination of arsenic in coprecipitated effluent, resulting in a significant decrease of arsenic (from 0.96 to less than 0.5 mg/L). The working capacity of zirconium-loaded nanocomposite was 220 bed volumes per run, much higher than that of ferric-loaded nanocomposite (40 bed volumes per run). The exhausted zirconium-loaded nanocomposite could be efficiently in situ regenerated with a binary NaOH-NaCl solution for reuse without any significant capacity loss. The results validated the combinational coprecipitation/nano-adsorption process to be a potential alternative for effective arsenic removal from highly laden industrial effluent.

Impacts of amount of impregnated iron in granular activated carbon on arsenate adsorption capacities and kinetics.

PubMed

Chang, Qigang; Lin, Wei; Ying, Wei-Chi

2012-06-01

Iron-impregnated granular activated carbons (Fe-GAC) can remove arsenic effectively from water. In this study, Fe-GACs with iron content of 1.64 to 28.90% were synthesized using a new multi-step procedure for the investigation of effects of iron amount on arsenic adsorption capacities and kinetics. Langmuir model satisfactorily fit arsenic adsorption on Fe-GACs. The maximum arsenic adsorption capacity (q(m)) increased significantly with iron impregnation and reached 1,867 to 1,912 microg/g with iron content of 9.96 to 13.59%. Further increase of iron content (> 13.59%) caused gradual decrease of q(m). It was found that the amount of impregnated iron showed little impact on the affinity for arsenate. Kinetic study showed that the amount of impregnated iron affected the arsenic intraparticle diffusion rate greatly. The pseudo-second-order kinetic model fit arsenic adsorption kinetics on Fe-GACs better than the pseudo-first-order model. The arsenic adsorption rate increased with increasing of iron content from 1.64% to 13.59%, and then decreased with more impregnated iron (13.59 to 28.90%).

DIMETHYLTHIOARSINIC ANHYDRIDE: A STANDARD FOR ARSENIC SPECIATION

EPA Science Inventory

Dimethylthioarsinic acid (DMTAV) has recently been identified in biological, dietary and environmental matrices. The relevance of this compound to the toxicity of arsenic in humans is unknown and further exposure assessment and metabolic studies are difficult to conduct because ...

Combined administration of taurine and monoisoamyl DMSA protects arsenic induced oxidative injury in rats

PubMed Central

Chouhan, Swapnila; Kannan, Gurusamy M; Mittal, Megha; Swarnkar, Harimohan

2008-01-01

Arsenic is a naturally occurring element that is ubiquitously present in the environment. High concentration of naturally occurring arsenic in drinking water is a major health problem in different parts of the world. Despite arsenic being a health hazard and a well documented carcinogen, no safe, effective and specific preventive or therapeutic measures are available. Among various recent strategies adopted, administration of an antioxidant has been reported to be the most effective. The present study was designed to evaluate the therapeutic efficacy of monoisoamyl dimercaptosuccinic acid (MiADMSA), administered either individually or in combination with taurine post chronic arsenic exposure in rats. Arsenic exposed male rats (25 ppm, sodium arsenite in drinking water for 24 weeks) were treated with taurine (100 mg/kg, i.p., once daily), monoisoamyl dimercaptosuccinic acid (MiADMSA) (50 mg/kg, oral, once daily) either individually or in combination for 5 consecutive days. Biochemical variables indicative of oxidative stress along-with arsenic concentration in blood, liver and kidney were measured. Arsenic exposure significantly reduced blood δ-aminolevulinic acid dehydratase (ALAD) activity, a key enzyme involved in the heme biosynthesis and enhanced zinc protoporphyrin (ZPP) level. Clinical hematological variables like white blood cells (WBC), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) showed significant decrease with a significant elevation in platelet (PLT) count. These changes were accompanied by significant decrease in superoxide dismutase (SOD) activity and increased catalase activity. Arsenic exposure caused a significant decrease in hepatic and renal glutathione (GSH) level and an increase in oxidized glutathione (GSSG). These biochemical changes were correlated with an increased uptake of arsenic in blood, liver and kidney. Administration of taurine significantly reduced hepatic oxidative stress however co-administration of

Is arsenobetaine the major arsenic compound in the liver of birds marine mammals, and sea turtles?

NASA Astrophysics Data System (ADS)

Kubota, R.; Kunito, T.; Tanabe, S.

2003-05-01

Concentrations of total arsenic and individual arsenic compounds were determined in the livers of birds, marine mammals, and sea turtles by using hydride generation-atomic absorption spectrometry (HG-AAS) and high performance liquid chromatography/inductively coupled plasma-mass spectrometry (HPLC/ICP-MS). Marine mammals feeding on cephalopods and crustaceans accumulated higher arsenic concentrations than the species feeding on fishes. No significant age and gender differences in arsenic concentrations were observed for most of the species of marine mammals. Elevated total arsenic concentrations were found in livers of black-footed albatross and loggerhead turtles and these values were comparable to those of lower trophic marine animals. Arsenobetaine was the major arsenical in the livers of most of the species examined. Particularly, in seabirds, mean proportions of arsenobetaine was more than90% of total extractable arsenic In contast, arsenobetaine was a minor constituent in dugong. The compositions of arsenic compounds were different among the species examined. These results might be due to the differences in the metabolic capacity among species and/or the different compositions of arsenic compounds in their preys.

Associations between arsenic (+3 oxidation state) methyltransferase (AS3MT) and N-6 adenine-specific DNA methyltransferase 1 (N6AMT1) polymorphisms, arsenic metabolism, and cancer risk in a chilean population.

PubMed

de la Rosa, Rosemarie; Steinmaus, Craig; Akers, Nicholas K; Conde, Lucia; Ferreccio, Catterina; Kalman, David; Zhang, Kevin R; Skibola, Christine F; Smith, Allan H; Zhang, Luoping; Smith, Martyn T

2017-07-01

Inter-individual differences in arsenic metabolism have been linked to arsenic-related disease risks. Arsenic (+3) methyltransferase (AS3MT) is the primary enzyme involved in arsenic metabolism, and we previously demonstrated in vitro that N-6 adenine-specific DNA methyltransferase 1 (N6AMT1) also methylates the toxic inorganic arsenic (iAs) metabolite, monomethylarsonous acid (MMA), to the less toxic dimethylarsonic acid (DMA). Here, we evaluated whether AS3MT and N6AMT1 gene polymorphisms alter arsenic methylation and impact iAs-related cancer risks. We assessed AS3MT and N6AMT1 polymorphisms and urinary arsenic metabolites (%iAs, %MMA, %DMA) in 722 subjects from an arsenic-cancer case-control study in a uniquely exposed area in northern Chile. Polymorphisms were genotyped using a custom designed multiplex, ligation-dependent probe amplification (MLPA) assay for 6 AS3MT SNPs and 14 tag SNPs in the N6AMT1 gene. We found several AS3MT polymorphisms associated with both urinary arsenic metabolite profiles and cancer risk. For example, compared to wildtypes, individuals carrying minor alleles in AS3MT rs3740393 had lower %MMA (mean difference = -1.9%, 95% CI: -3.3, -0.4), higher %DMA (mean difference = 4.0%, 95% CI: 1.5, 6.5), and lower odds ratios for bladder (OR = 0.3; 95% CI: 0.1-0.6) and lung cancer (OR = 0.6; 95% CI: 0.2-1.1). Evidence of interaction was also observed for both lung and bladder cancer between these polymorphisms and elevated historical arsenic exposures. Clear associations were not seen for N6AMT1. These results are the first to demonstrate a direct association between AS3MT polymorphisms and arsenic-related internal cancer risk. This research could help identify subpopulations that are particularly vulnerable to arsenic-related disease. Environ. Mol. Mutagen. 58:411-422, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Evaluating the cement stabilization of arsenic-bearing iron wastes from drinking water treatment.

PubMed

Clancy, Tara M; Snyder, Kathryn V; Reddy, Raghav; Lanzirotti, Antonio; Amrose, Susan E; Raskin, Lutgarde; Hayes, Kim F

2015-12-30

Cement stabilization of arsenic-bearing wastes is recommended to limit arsenic release from wastes following disposal. Such stabilization has been demonstrated to reduce the arsenic concentration in the Toxicity Characteristic Leaching Procedure (TCLP), which regulates landfill disposal of arsenic waste. However, few studies have evaluated leaching from actual wastes under conditions similar to ultimate disposal environments. In this study, land disposal in areas where flooding is likely was simulated to test arsenic release from cement stabilized arsenic-bearing iron oxide wastes. After 406 days submersed in chemically simulated rainwater, <0.4% of total arsenic was leached, which was comparable to the amount leached during the TCLP (<0.3%). Short-term (18 h) modified TCLP tests (pH 3-12) found that cement stabilization lowered arsenic leaching at high pH, but increased leaching at pH<4.2 compared to non-stabilized wastes. Presenting the first characterization of cement stabilized waste using μXRF, these results revealed the majority of arsenic in cement stabilized waste remained associated with iron. This distribution of arsenic differed from previous observations of calcium-arsenic solid phases when arsenic salts were stabilized with cement, illustrating that the initial waste form influences the stabilized form. Overall, cement stabilization is effective for arsenic-bearing wastes when acidic conditions can be avoided. Copyright © 2015 Elsevier B.V. All rights reserved.

The fate of arsenic in sediments formed at a river confluence affected by acid mine drainage

NASA Astrophysics Data System (ADS)

Guerra, P. A.; Pasten, P. A.; Pizarro, G.; Simonson, K.; Escauriaza, C. R.; Gonzalez, C.; Bonilla, C.

2012-12-01

Fluvial confluences receiving acid mine drainage may play a critical role in a watershed as a suite of interactions between chemistry and hydrodynamics occur, determining the fate of toxic contaminants like arsenic. Solid reactive phases of iron and/or aluminum oxi-hydroxides may form or transform, ranging from iron oxide nanoparticles that aggregate and form floccules that are transported in the suspended load up to gravel and arsenic-rich rock coatings. In order to further understand the role of reactive fluvial confluences, we have studied the mixing between the Caracarani River (flow=170-640 L/s, pH 8, conductivity 1.5 mS/cm, total As<0.1 mg/L and total Fe< 5 mg/L) and the Azufre River (flow=45-245 L/s, pH<2, conductivity > 10 mS/cm, total As>2 mg/L, total Fe=35-125 mg/L), located in the Lluta watershed in northern Chile. This site is an excellent natural laboratory located in a water-scarce area, where the future construction of a dam has prompted the attention of decision makers and scientists interested in weighing the risks derived by the accumulation of arsenic-rich sediments. Suspended sediments (> 0.45 μm), riverbed sediments, and coated rocks were collected upstream and downstream from the confluence. Suspended sediments >0.45 μm and riverbed sediments were analyzed by total reflection x-ray fluorescence for metals, while coated river bed rocks were analyzed by chemical extractions and a semi-quantitative approach through portable x-ray fluorescence. Water from the Caracarani and Azufre rivers were mixed in the laboratory at different ratios and mixing velocities aiming to characterize the effect of the chemical-hydrodynamic environment where arsenic solids were formed at different locations in the confluence. Despite a wide range of iron and arsenic concentrations in the suspended sediments from the field (As=1037 ± 1372 mg/kg, Fe=21.0 ± 24.5 g/kg), we found a rather narrow As/Fe ratio, increasing from 36.5 to 55.2 mgAs/kgFe when the bulk water p

Low selenium status affects arsenic metabolites in an arsenic exposed population with skin lesions.

PubMed

Huang, Zhi; Pei, Qiuling; Sun, Guifan; Zhang, Sichum; Liang, Jiang; Gao, Yi; Zhang, Xinrong

2008-01-01

The antagonistic effects between selenium (Se) and arsenic (As) suggest that low selenium status plays important roles in arsenism development. However, no study has been reported for humans suffering from chronic arsenic exposure with low selenium status. Sixty-three subjects were divided into 2 experimental groups by skin lesions (including hyperkeratosis, depigmentation, and hyperpigmentation). Total urine and serum concentrations of arsenic and selenium were determined by ICP-MS with collision/reaction cell. Arsenic species were analysed by ICP-MS coupled with HPLC. The mean concentration of As in the drinking waters was 41.5 microg/l. The selenium dietary intake for the studied population was 31.7 microg Se/d, and which for the cases and controls were 25.9 and 36.3 microg Se/d, respectively. Compared with the controls, the skin lesions cases had lower selenium concentrations in serum and urine (41.4 vs 49.6 microg/l and 71.0 vs 78.8 microg/l, respectively), higher inorganic arsenic (iAs) in serum (5.2 vs 3.4 microg/l, P<0.01), higher percentages of iAs in serum and urine (20.2) vs 16.9% and 18.3 vs 14.5%, respectively, P<0.01) but lower percentages of monomethylarsonate (MMA) in serum (15.5 vs 18.8%, P<0.01) ans dimethylarsinate acid (DMA) in urine (65.1 vs 69.8%, P<0.01). Subjects with lower selenium concentrations in serum (<50 microg/l) had a stronger tendency to the risk of skin lesions than individual having higher selenium concentrations [odd ratio (OR), 7.3; 95% confidence interval (95% CI), 1.5-35.7; P=0.014]. This OR estimation was confirmed in those subjects having higher ratios of As/Se in urine and serum, with OR as high as 10.3 and 3.8 respectively. Lower serum selenium status (<50 microg/l) is significantly correlated to the arsenic-associated skin lesions in the arsenic exposed population. The accumulation of iAs and its inhibition to be biotransformed to DMA occurred in human due to chronic exposure of low selenium status.

Selective speciation and determination of inorganic arsenic in water, food and biological samples.

PubMed

Tuzen, Mustafa; Saygi, Kadriye Ozlem; Karaman, Isa; Soylak, Mustafa

2010-01-01

A procedure for the speciation of arsenic(III) and arsenic(V) in natural water samples has been established in the presented work. Arsenic(III) ions were quantitatively recovered on Alternaria solani coated Diaion HP-2MG resin at pH 7, while the recoveries of arsenic(V) was below 10%. Arsenic(V) in the mixing solution containing As(III) and As(V) was reduced by using KI and L(+) ascorbic acid solution, then the procedure was applied to determination of total arsenic. Arsenic(V) was calculated as the difference between the total arsenic content and As(III) content. The determination of arsenic was performed by using hydride generation atomic absorption spectrometry. The influences of some alkali, earth alkali and transition metals on the biosorption of arsenic(III) were investigated. The preconcentration factor was 35. The detection limits for As(III) (N=20, k=3) was found as 11 ng L(-1). The relative standard deviation and relative error of the determinations were found to be lower than 7% and 4%, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successively applied for the determination and speciation of inorganic arsenic in water, food and biological samples. Copyright 2009 Elsevier Ltd. All rights reserved.

Extraction techniques for arsenic species in rice flour and their speciation by HPLC-ICP-MS.

PubMed

Narukawa, Tomohiro; Suzuki, Toshihiro; Inagaki, Kazumi; Hioki, Akiharu

2014-12-01

The extraction of arsenic (As) species present in rice flour samples was investigated using different extracting solvents, and the concentration of each species was determined by HPLC-ICP-MS after heat-assisted extraction. The extraction efficiencies for total arsenic species and especially for arsenite [As(III)] and arsenate [As(V)] were investigated. As(III), As(V) and dimethylarsinic acid (DMAA) were found in the samples, and the concentration of DMAA did not vary with treatment conditions. However, the concentrations of extracted total arsenic and those of As(III) and As(V) depended on the extracting solvents. When an extracting solvent was highly acidic, the concentrations of extracted total arsenic were in good agreement with the total arsenic concentration determined by ICP-MS after microwave-assisted digestion, though a part of the As(V) was reduced to As(III) during the highly acidic extraction process. Extraction under neutral conditions increased the extracted As(V), but extracted total arsenic was decreased because a part of the As(III) could not be extracted. Optimum conditions for the extraction of As(III) and As(V) from rice flour samples are discussed to allow the accurate determinations of As(III), As(V) and DMAA in the rice flour samples. Heat block extraction techniques using 0.05 mol L(-1) HClO4 and silver-containing 0.15 mol L(-1) HNO3 were also developed. Copyright © 2014 Elsevier B.V. All rights reserved.

Superior removal of arsenic from water with zirconium metal-organic framework UiO-66.

PubMed

Wang, Chenghong; Liu, Xinlei; Chen, J Paul; Li, Kang

2015-11-12

In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5-280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds.

Superior removal of arsenic from water with zirconium metal-organic framework UiO-66

PubMed Central

Wang, Chenghong; Liu, Xinlei; Chen, J. Paul; Li, Kang

2015-01-01

In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5–280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds. PMID:26559001

Adsorption and removal of arsenic from water by iron ore mining waste.

PubMed

Nguyen, Tien Vinh; Nguyen, Thi Van Trang; Pham, Tuan Linh; Vigneswaran, Saravanamuth; Ngo, Huu Hao; Kandasamy, J; Nguyen, Hong Khanh; Nguyen, Duc Tho

2009-01-01

There is a global need to develop low-cost technologies to remove arsenic from water for individual household water supply. In this study, a purified and enriched waste material (treated magnetite waste, TMW) from the Trai Cau's iron ore mine in the Thai Nguyen Province in Vietnam was examined for its capacity to remove arsenic. The treatment system was packed with TMW that consisted of 75% of ferrous-ferric oxide (Fe(3)O(4)) and had a large surface area of 89.7 m(2)/g. The experiments were conducted at a filtration rate of 0.05 m/h to treat groundwater with an arsenic concentration of 380 microg/L and iron, manganese and phosphate concentrations of 2.07 mg/L, 0.093 mg/L and 1.6 mg/L respectively. The batch experimental results show that this new material was able to absorb up to 0.74 mg arsenic/g. The results also indicated that the treatment system removed more than 90% arsenic giving an effluent with an arsenic concentration of less than 30 microg/L while achieving a removal efficiency of about 80% for Mn(2 + ) and PO(4) (3-). This could be a promising and cost-effective new material for capturing arsenic as well as other metals from groundwater.

COMPLEMENTARY APPROACHES TO THE DETERMINATION OF ARSENIC SPECIES RELEVANT TO CONCENTRATED ANIMAL FEEDING OPERATIONS

EPA Science Inventory

Ion-exchange chromatography is the most often used analytical approach for arsenic

speciation, due to the weak-acid nature of several of its species. However, no single

technique can determine all potentially occurring arsenic species, especially in complex

e...

Phytoremediation of arsenic contaminated soil by arsenic accumulators: a three year study.

PubMed

Raj, Anshita; Singh, Nandita

2015-03-01

To investigate whether phytoremediation can remove arsenic from the contaminated area, a study was conducted for three consecutive years to determine the efficiency of Pteris vittata, Adiantum capillus veneris, Christella dentata and Phragmites karka, on arsenic removal from the arsenic contaminated soil. Arsenic concentrations in the soil samples were analysed after harvesting in 2009, 2010 and 2011 at an interval of 6 months. Frond arsenic concentrations were also estimated in all the successive harvests. Fronds resulted in the greatest amount of arsenic removal. Root arsenic concentrations were analysed in the last harvest. Approximately 70 % of arsenic was removed by P. vittata which was recorded as the highest among the four plant species. However, 60 % of arsenic was removed by A. capillus veneris, 55.1 % by C. dentata and 56.1 % by P. karka of arsenic was removed from the contaminated soil in 3 years.

Report of the key comparison CCQM-K108 determination of arsenic species, total arsenic and cadmium in brown rice flour

NASA Astrophysics Data System (ADS)

Hioki, Akiharu; Narukawa, Tomohiro; Inagaki, Kazumi; Miyashita, Shinichi; Kotzeva, Boriana; Kakoulides, Elias; Sxoina, Vasiliki; Fung, W. H.; Choi, Y. Y.; Yau, H. P.; Tsoi, Y. T.; Lee, C. L.; Kong, M. F.; Shin, Richard; Juan, Wang; Sin Yee, Ng; Uribe, Christian; Marques Rodrigues, Janaína; Caciano de Sena, Rodrigo; Silva Dutra, Emily; Bergamaschi, Luigi; Giordani, Laura; D'Agostino, Giancarlo; Valiente, Liliana; Horvat, Milena; Jacimovic, Radojko; Oduor Okumu, Tom; Kang'Iri, Jacqueline; Owiti Orwa, Tabitha; Chao, Wei; Jingbo, Chao; Taebunpakul, Sutthinun; Yafa, Charun; Kaewkhomdee, Nattikarn; Chailap, Benjamat; Pharat, Yanee; Phukphattanachai, Pranee; Turk, Gregory C.; Long, Stephen; Murphy, K. E.; Davis, Clay; Ellisor, Michael; Merrick, Jeffrey; White, Ian; Saxby, David; Linsky, S. M.; Barzev, A.; Botha, A.

2015-01-01

The CCQM-K108 key comparison was organised by the Inorganic Analysis Working Group (IAWG) of CCQM to test the abilities of national metrology institutes (NMIs) or designated institutes (DIs) to measure the mass fractions of arsenic species, total arsenic and cadmium in brown rice flour. The National Metrology Institute of Japan (NMIJ) acted as the coordinating laboratory. The participants used different measurement methods, though most of them used inductively coupled plasma mass spectrometry (ICP-MS) or isotope-dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) for Cd and ICP-MS for total arsenic. Regarding arsenic speciation, all participants used ICP-MS coupled with liquid chromatography (LC). Accounting for relative expanded uncertainty, comparability of measurement results for each of total arsenic and cadmium was successfully demonstrated by the participating NMIs or DIs for the measurement of the measurand at the level of less than 0.5 mg/kg. Regarding arsenic species (inorganic arsenic and dimethylarsinic acid (DMAA)), there was, however, a measurement problem still to be solved and that part of CCQM-K108 will be repeated. It is expected that arsenic, cadmium and other metals at mass fractions greater than approximately 0.1 mg/kg in rice flour can be determined by each participant using the same technique(s) employed for this key comparison to achieve similar uncertainties mentioned in the present report. Furthermore, the results of this key comparison can be utilised along with the IAWG core capability approach. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Arsenic methylation capability and hypertension risk in subjects living in arseniasis-hyperendemic areas in southwestern Taiwan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Y.-K.; Tseng, C.-H.; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan

Background: Cumulative arsenic exposure (CAE) from drinking water has been shown to be associated with hypertension in a dose-response pattern. This study further explored the association between arsenic methylation capability and hypertension risk among residents of arseniasis-hyperendemic areas in Taiwan considering the effect of CAE and other potential confounders. Method: There were 871 subjects (488 women and 383 men) and among them 372 were diagnosed as having hypertension based on a positive history or measured systolic blood pressure {>=} 140 mm Hg and/or diastolic blood pressure {>=} 90 mm Hg. Urinary arsenic species were determined by high-performance liquid chromatography-hydride generatormore » and atomic absorption spectrometry. Primary arsenic methylation index [PMI, defined as monomethylarsonic acid (MMA{sup V}) divided by (As{sup III} + As{sup V})] and secondary arsenic methylation index (SMI, defined as dimethylarsinic acid divided by MMA{sup V}) were used as indicators for arsenic methylation capability. Results: The level of urinary arsenic was still significantly correlated with cumulative arsenic exposure (CAE) calculated from a questionnaire interview (p = 0.02) even after the residents stopped drinking the artesian well water for 2-3 decades. Hypertensive subjects had higher percentages of MMA{sup V} and lower SMI than subjects without hypertension. However, subjects having CAE > 0 mg/L-year had higher hypertension risk than those who had CAE = 0 mg/L-year disregard a high or low methylation index. Conclusion: Inefficient arsenic methylation ability may be related with hypertension risk.« less

Earth Abides Arsenic Biotransformations

NASA Astrophysics Data System (ADS)

Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

2014-05-01

Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice.

ARSENIC REMOVAL

EPA Science Inventory

Presentation covered five topics; arsenic chemistry, best available technology (BAT), surface water technology, ground water technology and case studies of arsenic removal. The discussion on arsenic chemistry focused on the need and method of speciation for AsIII and AsV. BAT me...

SOME CHEMICAL PROPERTIES UNDERLYING ARSENIC'S BIOLOGICAL ACTIVITY

EPA Science Inventory

ABSTRACT

In this paper some of the chemical properties of arsenicals (atomic
and molecular orbitals, electronegativity, valence state, changes between
valence state, nucleophilicity, the hard/soft acid/base principle) that may
account for some of the b...

Speciation and monitoring test for inorganic arsenic in white rice flour.

PubMed

Narukawa, Tomohiro; Hioki, Akiharu; Chiba, Koichi

2012-02-01

A monitoring test for arsenic species in white rice flour was developed and applied to flours made from 20 samples of polished rice collected from locations all over Japan. The arsenic species in white rice flour made from five samples each of four types of rice were analyzed by HPLC-ICP-MS after a heat-assisted aqueous extraction. The total arsenic and major and minor element concentrations in the white rice flours were measured by ICP-MS and ICP-OES after microwave-assisted digestion. 91 ± 1% of the arsenic in the flours was extractable. Concentrations of arsenite [As(III)], arsenate [As(V)], and dimethylarsinic acid (DMAA) were closely positively correlated with the total arsenic concentrations. The total arsenic concentration in flours made from rice collected around Japan was 0.15 ± 0.07 mg kg(-1) (highest, 0.32 mg kg(-1)), which is very low. It was thus confirmed that the white rice flour samples collected in this experiment were not suffered from noticeable As contamination.

Arsenic metabolism by microbial communities from an arsenic-rich shallow-water hydrothermal system in Ambitle Island, Papua New Guinea

NASA Astrophysics Data System (ADS)

Ruiz Chancho, M.; Pichler, T.; Amend, J. P.; Akerman, N. H.

2011-12-01

Arsenic, although toxic, is used as an energy source by certain microbes, some of which can catalyse the reduction of arsenate by using different electron donors, while others oxidize arsenite with oxygen or nitrate as electron acceptors. The marine shallow-water hydrothermal system in Tutum Bay, Ambitle Island, Papua New Guinea is ideal for investigating the metabolism of microbes involved in arsenic cycling, because there hydrothermal vents discharge fluids with arsenite concentrations as high as 950 μg/L. Vent fluids are hot (˜100°C), slightly acidic (pH˜6) and reducing. Upon mixing with colder and oxygen-rich seawater the fluid chemistry changes rapidly within a few meters from the hydrothermal source. The objective of this work was to study arsenic metabolism due to microbial activity in Tutum Bay. Sediments collected at 7.5 and 30 m along a transect beginning at a hydrothermal vent were used as inocula in the microbial culturing experiments. Media were designed using chemical analyses of the hydrothermal fluids. Following culture experiments, arsenic species identification and quantification were performed for the growth media with HPLC-ICP(HR)MS, using anion exchange and reversed phase chromatography. Quality control included mass balance calculations and spiking experiments. A fast reduction of arsenate to arsenite was observed in the first 24 hours leading to the conclusion that the microbial communities were capable of reducing arsenic. However, mass balance calculations revealed that more than 30% of the arsenic had been transformed to one or more unknown species, which could not be detected by ion exchange chromatography. The addition of peroxide combined with reversed phase chromatography revealed the presence of several unknown species. Following the addition of peroxide some of the unknown species were identified to be thio-arsenic compounds, because they were oxidized to their oxo-analogues. Nevertheless, a significant fraction of unknown

Arsenic Speciation and Accumulation in Selected Organs after Oral Administration of Rice Extracts in Wistar Rats.

PubMed

Lewchalermvong, Kittima; Rangkadilok, Nuchanart; Nookabkaew, Sumontha; Suriyo, Tawit; Satayavivad, Jutamaad

2018-03-28

Despite its nutritional values, rice also contains arsenic. There has been increasing concern about health implications associated with exposure to arsenic through rice consumption. The present study evaluated arsenic accumulation and its speciation in selected organs of Wistar rats after 28 day repeated oral administrations of polished or unpolished rice and their control arsenic compounds (sodium arsenite or dimethylarsinic acid; DMA). Only the treatment of sodium arsenite (2 μg/kg body weight), significantly increased total arsenic concentrations in blood when compared to the distilled water control group. In all groups, total arsenic concentrations were highest in kidney (1.54-1.90 mg/kg) followed by liver (0.85-1.52 mg/kg), and the predominant arsenic form in these organs was DMA. However, there was no significant difference in arsenic accumulation in the measured organs among the control and rice-treated groups. Therefore, the repeated 28 day administration of arsenic-contaminated rice did not cause significant arsenic accumulation in the animal organs.

Arsenic surveillance program

NASA Technical Reports Server (NTRS)

1993-01-01

Background information about arsenic is presented including forms, common sources, and clinical symptoms of arsenic exposure. The purpose of the Arsenic Surveillance Program and LeRC is outlined, and the specifics of the Medical Surveillance Program for Arsenic Exposure at LeRC are discussed.

[The establishment of the arsenic poisoning rats model caused by corn flour baked by high-arsenic coal].

PubMed

Yao, Mao-lin; Zhang, Ai-hua; Yu, Chun; Xu, Yu-yan; Hu, Yong; Xiao, Ting-ting; Wang, Lei

2013-09-01

mitochondrial, the blurred mitochondrial cristae, some disappeared ridges, the reduced rough endoplasmic reticulum, and irregular uneven nuclear in the liver cells of rats in arsenic contaminated grain group. The contents of aspartate transaminase (AST) and total bile acid (TBA) in medium and high arsenic contaminated grain group were respectively (196.17 ± 46.18), (212.40 ± 35.14) U/L and (11.74 ± 4.07), (19.19 ± 4.68)µmol/L, which were higher than it in the control group (separately (143.10 ± 29.13) U/L and (6.23 ± 2.95)µmol/L). The contents of glutathione-S-transferases(GST), γ-glutamyltranspeptidase (GGT)and blood urea nitrogen (BUN)in high arsenic contaminated grain group were separately (196.21 ± 47.38)U/L, (1.71 ± 0.66)U/L, (9.54 ± 1.95)mmol/L, which were higher than that in the control group ((134.93 ± 24.80 )U/L, (0.75 ± 0.36)U/L, (7.67 ± 1.02)mmol/L, respectively). The contents of cholinesterase (CHE) in low, medium and high arsenic contaminated grain group were separately (259.90 ± 52.71)U/L, (263.44 ± 66.06)U/L and (244.90 ± 36.14)U/L, the contents of total protein(TP) in rats of high arsenic contaminated grain group were (62.64 ± 5.50)g/L, which was all lower than that in the control group ((448.33 ± 59.67)U/L, (69.38 ± 4.24)g/L, respectively). The contents of TBA in high arsenic contaminated grain group ( (19.19 ± 4.68) µmol/L) was higher than that in drinking water arsenic poisoning group ((15.15 ± 2.64)µmol/L). The differences of the above indexes were all significant (P < 0.05). The results showed the arsenic poisoning rat model produced by coal-burning were successfully established.

Establishment of a method for determination of arsenic species in seafood by LC-ICP-MS.

PubMed

Zmozinski, Ariane V; Llorente-Mirandes, Toni; López-Sánchez, José F; da Silva, Márcia M

2015-04-15

An analytical method for determination of arsenic species (inorganic arsenic (iAs), methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO) and arsenocholine (AC)) in Brazilian and Spanish seafood samples is reported. This study was focused on extraction and quantification of inorganic arsenic (iAs), the most toxic form. Arsenic speciation was carried out via LC with both anionic and cationic exchange with ICP-MS detection (LC-ICP-MS). The detection limits (LODs), quantification limits (LOQs), precision and accuracy for arsenic species were established. The proposed method was evaluated using eight reference materials (RMs). Arsenobetaine was the main species found in all samples. The total and iAs concentration in 22 seafood samples and RMs ranged between 0.27-35.2 and 0.02-0.71 mg As kg(-1), respectively. Recoveries ranging from 100% to 106% for iAs, based on spikes, were achieved. The proposed method provides reliable iAs data for future risk assessment analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Arsenic species separation by IELC-ICP/OES: Arsenocholine behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rubio, R.; Peralta, I.; Alberti, J.

1993-01-01

In the literature an increasing interest is observed in developing methods to determine arsenobetaine, arsenocholine and related compounds in sea food and in reference materials. The separation conditions and quantification of As(III), As(V), monomethylarsenate (MMA), dimethylarsinate (DMA), arsenobetaine (AsBet) and arsenocholine (AsChol) are studied by Liquid Chromatography (LC) coupled directly to an Inductively Coupled Plasma Optical Emission Spectroscopy (ICP/OES) system. The separation conditions are optimized to improve the resolution of the six arsenic species. Arsenocholine shows a particular pattern of behavior when phosphate is used as eluent: two peaks are observed in the chromatogram, thus a systematic study assaying differentmore » pH and concentration of phosphate is carried out to improve resolution and analysis time when the six arsenic compounds are analyzed in a mixture. Boric acid as mobile phase avoids the splitting of the arsenocholine peak and leads to a good separation of the six arsenic compounds. Detection limits are established for the six arsenic species.« less

Blood Pressure Associated with Arsenic Methylation and Arsenic Metabolism Caused by Chronic Exposure to Arsenic in Tube Well Water.

PubMed

Wei, Bing Gan; Ye, Bi Xiong; Yu, Jiang Ping; Yang, Lin Sheng; Li, Hai Rong; Xia, Ya Juan; Wu, Ke Gong

2017-05-01

The effects of arsenic exposure from drinking water, arsenic metabolism, and arsenic methylation on blood pressure (BP) were observed in this study. The BP and arsenic species of 560 participants were determined. Logistic regression analysis was applied to estimate the odds ratios of BP associated with arsenic metabolites and arsenic methylation capability. BP was positively associated with cumulative arsenic exposure (CAE). Subjects with abnormal diastolic blood pressure (DBP), systolic blood pressure (SBP), and pulse pressure (PP) usually had higher urinary iAs (inorganic arsenic), MMA (monomethylated arsenic), DMA (dimethylated arsenic), and TAs (total arsenic) than subjects with normal DBP, SBP, and PP. The iAs%, MMA%, and DMA% differed slightly between subjects with abnormal BP and those with normal BP. The PMI and SMI were slightly higher in subjects with abnormal PP than in those with normal PP. Our findings suggest that higher CAE may elevate BP. Males may have a higher risk of abnormal DBP, whereas females have a higher risk of abnormal SBP and PP. Higher urinary iAs may increase the risk of abnormal BP. Lower PMI may elevate the BP. However, higher SMI may increase the DBP and SBP, and lower SMI may elevate the PP. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Nrf2 activation ameliorates cytotoxic effects of arsenic trioxide in acute promyelocytic leukemia cells through increased glutathione levels and arsenic efflux from cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishimoto, Shoichi; Suzuki, Toshihiro; Koike, Shin

Carnosic acid (CA), a phenolic diterpene isolated from Rosmarinus officinalis, has been shown to activate nuclear transcription factor E2-related factor 2 (Nrf2), which plays a central role in cytoprotective responses to oxidative and electrophilic stress. Recently, the Nrf2-Kelch ECH associating protein 1 (Keap1) pathway has been associated with cancer drug resistance attributable to modulation of the expression and activation of antioxidant and detoxification enzymes. However, the exact mechanisms by which Nrf2 activation results in chemoresistance are insufficiently understood to date. This study investigated the mechanisms by which the cytotoxic effects of arsenic trioxide (ATO), an anticancer drug, were decreased inmore » acute promyelocytic leukemia cells treated with CA, a typical activator of Nrf2 used to stimulate the Nrf2/Keap1 system. Our findings suggest that arsenic is non-enzymatically incorporated into NB4 cells and forms complexes that are dependent on intracellular glutathione (GSH) concentrations. In addition, the arsenic complexes are recognized as substrates by multidrug resistance proteins and subsequently excreted from the cells. Therefore, Nrf2-associated activation of the GSH biosynthetic pathway, followed by increased levels of intracellular GSH, are key mechanisms underlying accelerated arsenic efflux and attenuation of the cytotoxic effects of ATO. - Highlights: • Nrf2 activation attenuates the effect of arsenic trioxide to acute promyelocytic leukemia cells. • The sensitivity of arsenic trioxide to NB4 cells was dependent on efflux rate of arsenic. • Activation of the GSH biosynthesis is essential in Nrf2-regulated responses for arsenic efflux.« less

Field and laboratory arsenic speciation methods and their application to natural-water analysis

USGS Publications Warehouse

Bednar, A.J.; Garbarino, J.R.; Burkhardt, M.R.; Ranville, J.F.; Wildeman, T.R.

2004-01-01

The toxic and carcinogenic properties of inorganic and organic arsenic species make their determination in natural water vitally important. Determination of individual inorganic and organic arsenic species is critical because the toxicology, mobility, and adsorptivity vary substantially. Several methods for the speciation of arsenic in groundwater, surface-water, and acid mine drainage sample matrices using field and laboratory techniques are presented. The methods provide quantitative determination of arsenite [As(III)], arsenate [As(V)], monomethylarsonate (MMA), dimethylarsinate (DMA), and roxarsone in 2-8min at detection limits of less than 1??g arsenic per liter (??g AsL-1). All the methods use anion exchange chromatography to separate the arsenic species and inductively coupled plasma-mass spectrometry as an arsenic-specific detector. Different methods were needed because some sample matrices did not have all arsenic species present or were incompatible with particular high-performance liquid chromatography (HPLC) mobile phases. The bias and variability of the methods were evaluated using total arsenic, As(III), As(V), DMA, and MMA results from more than 100 surface-water, groundwater, and acid mine drainage samples, and reference materials. Concentrations in test samples were as much as 13,000??g AsL-1 for As(III) and 3700??g AsL-1 for As(V). Methylated arsenic species were less than 100??g AsL-1 and were found only in certain surface-water samples, and roxarsone was not detected in any of the water samples tested. The distribution of inorganic arsenic species in the test samples ranged from 0% to 90% As(III). Laboratory-speciation method variability for As(III), As(V), MMA, and DMA in reagent water at 0.5??g AsL-1 was 8-13% (n=7). Field-speciation method variability for As(III) and As(V) at 1??g AsL-1 in reagent water was 3-4% (n=3). ?? 2003 Elsevier Ltd. All rights reserved.

Assessment of arsenic exposures and controls in gallium arsenide production.

PubMed

Sheehy, J W; Jones, J H

1993-02-01

The electronics industry is expanding the use of gallium arsenide in the production of optoelectronic devices and integrated circuits. Workers in the electronics industry using gallium arsenide are exposed to hazardous substances such as arsenic, arsine, and various acids. Arsenic requires stringent controls to minimize exposures (the current OSHA PEL for arsenic is 10 micrograms/m3 and the NIOSH REL is 2 micrograms/m3 ceiling). Inorganic arsenic is strongly implicated in respiratory tract and skin cancer. For these reasons, NIOSH researchers conducted a study of control systems for facilities using gallium arsenide. Seven walk-through surveys were performed to identify locations for detailed study which appeared to have effective controls; three facilities were chosen for in-depth evaluation. The controls were evaluated by industrial hygiene sampling. Including personal breathing zone and area air sampling for arsenic and arsine; wipe samples for arsenic also were collected. Work practices and the use of personal protective equipment were documented. This paper reports on the controls and the arsenic exposure results from the evaluation of the following gallium arsenide processes: Liquid Encapsulated Czochralski (LEC) and Horizontal Bridgeman (HB) crystal growing, LEC cleaning operations, ingot grinding/wafer sawing, and epitaxy. Results at one plant showed that in all processes except epitaxy, average arsenic exposures were at or above the OSHA action level of 5 micrograms/m3. While cleaning the LEC crystal pullers, the average potential arsenic exposure of the cleaning operators was 100 times the OSHA PEL. At the other two plants, personal exposures for arsenic were well controlled in LEC, LEC cleaning, grinding/sawing, and epitaxy operations.

Removal of Arsenic (III, V) from aqueous solution by nanoscale zero-valent iron stabilized with starch and carboxymethyl cellulose

PubMed Central

2014-01-01

In this work, synthetic nanoscale zerovalent iron (NZVI) stabilized with two polymers, Starch and Carboxymethyl cellulose (CMC) were examined and compared for their ability in removing As (III) and As (V) from aqueous solutions as the most promising iron nanoparticles form for arsenic removal. Batch operations were conducted with different process parameters such as contact time, nanoparticles concentration, initial arsenic concentration and pH. Results revealed that starch stabilized particles (S-nZVI) presented an outstanding ability to remove both arsenate and arsenite and displayed ~ 36.5% greater removal for As (V) and 30% for As (III) in comparison with CMC-stabilized nanoparticles (C-nZVI). However, from the particle stabilization viewpoint, there is a clear trade off to choosing the best stabilized nanoparticles form. Removal efficiency was enhanced with increasing the contact time and iron loading but reduced with increasing initial As (III, V) concentrations and pH. Almost complete removal of arsenic (up to 500 μg/L) was achieved in just 5 min when the S-nZVI mass concentration was 0.3 g/L and initial solution pH of 7 ± 0.1. The maximum removal efficiency of both arsenic species was obtained at pH = 5 ± 0.1 and starched nanoparticles was effective in slightly acidic and natural pH values. The adsorption kinetics fitted well with pseudo-second-order model and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 14 mg/g for arsenic (V), and 12.2 mg/g for arsenic (III). It could be concluded that starch stabilized Fe0 nanoparticles showed remarkable potential for As (III, V) removal from aqueous solution e.g. contaminated water. PMID:24860660

Biological attenuation of arsenic and iron in a continuous flow bioreactor treating acid mine drainage (AMD).

PubMed

Fernandez-Rojo, L; Héry, M; Le Pape, P; Braungardt, C; Desoeuvre, A; Torres, E; Tardy, V; Resongles, E; Laroche, E; Delpoux, S; Joulian, C; Battaglia-Brunet, F; Boisson, J; Grapin, G; Morin, G; Casiot, C

2017-10-15

Passive water treatments based on biological attenuation can be effective for arsenic-rich acid mine drainage (AMD). However, the key factors driving the biological processes involved in this attenuation are not well-known. Here, the efficiency of arsenic (As) removal was investigated in a bench-scale continuous flow channel bioreactor treating As-rich AMD (∼30-40 mg L -1 ). In this bioreactor, As removal proceeds via the formation of biogenic precipitates consisting of iron- and arsenic-rich mineral phases encrusting a microbial biofilm. Ferrous iron (Fe(II)) oxidation and iron (Fe) and arsenic removal rates were monitored at two different water heights (4 and 25 mm) and with/without forced aeration. A maximum of 80% As removal was achieved within 500 min at the lowest water height. This operating condition promoted intense Fe(II) microbial oxidation and subsequent precipitation of As-bearing schwertmannite and amorphous ferric arsenate. Higher water height slowed down Fe(II) oxidation, Fe precipitation and As removal, in relation with limited oxygen transfer through the water column. The lower oxygen transfer at higher water height could be partly counteracted by aeration. The presence of an iridescent floating film that developed at the water surface was found to limit oxygen transfer to the water column and delayed Fe(II) oxidation, but did not affect As removal. The bacterial community structure in the biogenic precipitates in the bottom of the bioreactor differed from that of the inlet water and was influenced to some extent by water height and aeration. Although potential for microbial mediated As oxidation was revealed by the detection of aioA genes, removal of Fe and As was mainly attributable to microbial Fe oxidation activity. Increasing the proportion of dissolved As(V) in the inlet water improved As removal and favoured the formation of amorphous ferric arsenate over As-sorbed schwertmannite. This study proved the ability of this bioreactor

Heat Capacity of B. Mori Silk Fibroin Based on the Vibrational-Motion of Poly(amino acid)s.

NASA Astrophysics Data System (ADS)

Pyda, Marek; Hu, Xiao; Cebe, Peggy

2009-03-01

Bombyx mori silk fibroin heat capacities with and without water have been determined based on the vibrational motions of poly(amino acid)s and water, using the Advanced Thermal Analysis System (ATHAS) Data Bank. The heat capacities, Cp, of dry silk and silk-water were linked to their vibrational spectra based on the group and skeletal vibration contributions. For dry silk, the experimental and calculated Cp agree to better than ±3% between 200 K and 435 K. The heat capacity of the solid silk-water system, below the glass transition, was estimated from a sum of linear combinations of the molar fractions of the vibrational heat capacities of dry silk and glassy water. Calculations are compared to experimental data obtained from calorimetric methods, using hermetic and non-hermetic pans. The approach presented allows one to predict the low temperature vibrational heat capacity for dry silk and for the silk-water system down to zero kelvin, and, together with an extension to higher temperatures, above the glass transition. This can be used as a reference baseline for quantitative thermal analysis of this biomaterial..

A novel approach for arsenic adsorbents regeneration using MgO.

PubMed

Tresintsi, Sofia; Simeonidis, Konstantinos; Katsikini, Maria; Paloura, Eleni C; Bantsis, Georgios; Mitrakas, Manassis

2014-01-30

An integrated procedure for the regeneration of iron oxy-hydroxide arsenic adsorbents by granulated MgO is proposed in this study. A continuous recirculation configuration, with a NaOH solution flowing sequentially through the saturated adsorbent (leaching step) and the MgO (adsorption step) column beds, was optimized by utilizing the high arsenic adsorption efficiency of MgO at strong alkaline environments. Experimental results indicated that the total amount of leached arsenic was captured by MgO whereas the regenerated iron oxy-hydroxide recovered around 80% of its removal capacity upon reuse. The improved adsorption capacity of MgO for As(V), which is maximized at pH 10, is explained by the intermediate hydration to Mg(OH)2 and the following As(V) oxy-anions adsorption on its surface through the formation of monodentate inner sphere complexes, as it is deduced from the AsK-edge X-ray absorption fine structure (EXAFS) analysis. In addition to the economical-benefits, corresponding tests proved that the solid wastes of this process, namely spent MgO/Mg(OH)2, can be environmentally safely disposed as stable additives in cement products, while the alkaline solution is completely detoxified and can be recycled to the regeneration task. Copyright © 2013 Elsevier B.V. All rights reserved.

Heat Capacity Changes Associated with Nucleic Acid Folding

PubMed Central

Mikulecky, Peter J.; Feig, Andrew L.

2008-01-01

Whereas heat capacity changes (ΔCPs) associated with folding transitions are commonplace in the literature of protein folding, they have long been considered a minor energetic contributor in nucleic acid folding. Recent advances in the understanding of nucleic acid folding and improved technology for measuring the energetics of folding transitions have allowed a greater experimental window for measuring these effects. We present in this review a survey of current literature that confronts the issue of ΔCPs associated with nucleic acid folding transitions. This work helps to gather the molecular insights that can be gleaned from analysis of ΔCPs and points toward the challenges that will need to be overcome if the energetic contribution of ΔCP terms are to be put to use in improving free energy calculations for nucleic acid structure prediction. PMID:16429398

Acid-producing capacity from sugars and sugar alcohols among Lactobacillus isolates collected in connection with radiation therapy.

PubMed

Almståhl, Annica; Rudbäck, Helena; Basic, Amina; Carlén, Anette; Alstad, Torgny

2017-12-01

To investigate the acid-producing capacity from sugars and sugar alcohols of oral Lactobacillus collected in connection with radiation therapy (RT) to the head and neck region. Lactobacillus were collected from the tongue, buccal mucosa and supragingival plaque in 24 patients before, during, and after RT. The acid-producing capacity of Lactobacillus isolates (n=211) was analyzed using a colorimetric fermentation test in microtiter plates. Solutions containing 2% sugars (sucrose, glucose, fructose, lactose) or sugar-alcohols (sorbitol and xylitol) were used. After 24h of incubation, bacterial acid-producing capacity was determined as strong (pH<5), weak (pH  ≥5-≤ 6) or low/absent (pH>6). Data regarding intake frequency of sugar-rich products and products with sugar-alcohols was collected. The highest acid-producing capacity using the sugars was seen for isolates collected during RT. Sorbitol was fermented to a higher extent during and post RT, especially among isolates from plaque. Lactobacillus fermenting xylitol showed the highest acid-producing capacity during RT (p<0.05). No statistically significant correlations between stimulated whole salivary secretion rate and acid-producing capacity, or between the intake frequency of sugar-rich products or sugar-alcohol containing products and Lactobacillus acid-producing capacity, were found. The results suggest that Lactobacillus isolates, collected from the tongue, buccal mucosa and supragingival plaque, have a higher acid-producing capacity using sugars and sugar-alcohols during RT than one year post RT. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cancer in Experimental Animals Exposed to Arsenic and Arsenic Compounds

PubMed Central

Tokar, Erik J.; Benbrahim-Tallaa, Lamia; Ward, Jerold M.; Lunn, Ruth; Sams, Reeder L.; Waalkes, Michael P.

2011-01-01

Inorganic arsenic is a ubiquitous environmental contaminant that has long been considered a human carcinogen. Recent studies raise further concern about the metalloid as a major, naturally occurring carcinogen in the environment. However, during this same period it has proven difficult to provide experimental evidence of the carcinogenicity of inorganic arsenic in laboratory animals and, until recently, there was considered to be a lack of clear evidence for carcinogenicity of any arsenical in animals. More recent work with arsenical methylation metabolites and early life exposures to inorganic arsenic has now provided evidence of carcinogenicity in rodents. Given that tens of millions of people worldwide are exposed to potentially unhealthy levels of environmental arsenic, in vivo rodent models of arsenic carcinogenesis are a clear necessity for resolving critical issues, like mechanisms of action, target tissue specificity, and sensitive subpopulations, and in developing strategies to reduce cancers in exposed human populations. This work reviews the available rodent studies considered relevant to carcinogenic assessment of arsenicals, taking advantage of the most recent review by the International Agency for Research on Cancer (IARC) that has not yet appeared as a full monograph but has been summarized (IARC 2009). Many valid studies show that arsenic can interact with other carcinogens/agents to enhance oncogenesis, and help elucidate mechanisms, and these too are summarized in this review. Finally, this body of rodent work is discussed in light of its impact on mechanisms and in the context of the persistent argument that arsenic is not carcinogenic in animals. PMID:20812815

Organic arsenicals as efficient and highly specific linkers for protein/peptide-polymer conjugation.

PubMed

Wilson, Paul; Anastasaki, Athina; Owen, Matthew R; Kempe, Kristian; Haddleton, David M; Mann, Sarah K; Johnston, Angus P R; Quinn, John F; Whittaker, Michael R; Hogg, Philip J; Davis, Thomas P

2015-04-01

The entropy-driven affinity of trivalent (in)organic arsenicals for closely spaced dithiols has been exploited to develop a novel route to peptide/protein-polymer conjugation. A trivalent arsenous acid (As(III)) derivative (1) obtained from p-arsanilic acid (As(V)) was shown to readily undergo conjugation to the therapeutic peptide salmon calcitonin (sCT) via bridging of the Cys(1)-Cys(7) disulfide, which was verified by RP-HPLC and MALDI-ToF-MS. Conjugation was shown to proceed rapidly (t < 2 min) in situ and stoichiometrically through sequential reduction-conjugation protocols, therefore exhibiting conjugation efficiencies equivalent to those reported for the current leading disulfide-bond targeting strategies. Furthermore, using bovine serum albumin as a model protein, the trivalent organic arsenical 1 was found to demonstrate enhanced specificity for disulfide-bond bridging in the presence of free cysteine residues relative to established maleimide functional reagents. This specificity represents a shift toward potential orthogonality, by clearly distinguishing between the reactivity of mono- and disulfide-derived (vicinal or neighbors-through-space) dithiols. Finally, p-arsanilic acid was transformed into an initiator for aqueous single electron-transfer living radical polymerization, allowing the synthesis of hydrophilic arsenic-functional polymers which were shown to exhibit negligible cytotoxicity relative to a small molecule organic arsenical, and an unfunctionalized polymer control. Poly(poly[ethylene glycol] methyl ether acrylate) (PPEGA480, DPn = 10, Mn,NMR = 4900 g·mol(-1), Đ = 1.07) possessing a pentavalent arsenic acid (As(V)) α-chain end was transformed into trivalent As(III) post-polymerization via initial reduction by biological reducing agent glutathione (GSH), followed by binding of GSH. Conjugation of the resulting As(III)-functional polymer to sCT was realized within 35 min as indicated by RP-HPLC and verified later by thermodynamically

Stabilization of arsenic and fluoride bearing spent adsorbent in clay bricks: Preparation, characterization and leaching studies.

PubMed

Rathore, Vineet Kumar; Mondal, Prasenjit

2017-09-15

The presence of arsenic and fluoride in groundwater has been observed throughout the world. Many technologies have been developed by various research groups in order to tackle this problem. Adsorption has emerged as one of the best possible technique for the removal of arsenic, fluoride and many other pollutants from drinking water. Although a considerable amount of work has been published on the adsorptive removal of arsenic and fluoride, the area related to the management of spent adsorbent is not well explored. Present paper deals with the adsorptive removal of arsenic and fluoride from aqueous solution by three different types of adsorbents, namely, thermally treated laterite (TTL), acid-base treated laterite (ABTL) and aluminum oxide/hydroxide nanoparticles (AHNP). Under the experimental conditions in batch operation, the adsorption capacities of TTL, ABLT and AHNP for arsenic are found to be 6.43 μg/g, 9.25 μg/g and 48.5 μg/g respectively, whereas for fluoride, these values are found as 0.21 mg/g, 0.85 mg/g and 4.65 mg/g respectively. After adsorption, the spent adsorbents have been stabilized in the form of clay bricks. The effects of spent adsorbent concentration on the properties of bricks and their leaching properties are investigated. The bricks have been tested for various properties like density, percentage water absorption, shrinkage, compressive strength and efflorescence. The maximum values of density and shrinkage of the bricks formed are found as 2.3 g/cm 3 and 10.2%, whereas the percentage water absorption and compressive strength of the bricks are found between 11 and 14% and 35 to 150 kgf/cm 2 respectively. All the test results are in accordance with the criteria set by Indian Standards. The leaching test of arsenic and fluoride from the bricks reveals that their maximum values in leachate are 510 μg/L and 2.1 mg/L respectively, which are below the permissible limits of USEPA standards. Copyright © 2017 Elsevier Ltd. All rights

Acute promyelocytic leukemia, arsenic, and PML bodies

PubMed Central

Le Bras, Morgane; Lallemand-Breitenbach, Valérie

2012-01-01

Acute promyelocytic leukemia (APL) is driven by a chromosomal translocation whose product, the PML/retinoic acid (RA) receptor α (RARA) fusion protein, affects both nuclear receptor signaling and PML body assembly. Dissection of APL pathogenesis has led to the rediscovery of PML bodies and revealed their role in cell senescence, disease pathogenesis, and responsiveness to treatment. APL is remarkable because of the fortuitous identification of two clinically effective therapies, RA and arsenic, both of which degrade PML/RARA oncoprotein and, together, cure APL. Analysis of arsenic-induced PML or PML/RARA degradation has implicated oxidative stress in the biogenesis of nuclear bodies and SUMO in their degradation. PMID:22778276

HPLC-ICP-MS speciation analysis of arsenic in urine of Japanese subjects without occupational exposure.

PubMed

Hata, Akihisa; Endo, Yoko; Nakajima, Yoshiaki; Ikebe, Maiko; Ogawa, Masanori; Fujitani, Noboru; Endo, Ginji

2007-05-01

The toxicity and carcinogenicity of arsenic depend on its species. Individuals living in Japan consume much seafood that contains high levels of organoarsenics. Speciation analysis of urinary arsenic is required to clarify the health risks of arsenic intake. There has been no report of urinary arsenic analysis in Japan using high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). We performed speciation analysis of urinary arsenic for 210 Japanese male subjects without occupational exposure using HPLC-ICP-MS. The median values of urinary arsenics were as follows: sodium arsenite (AsIII), 3.5; sodium arsenate (AsV), 0.1; monomethylarsonic acid (MMA), 3.1; dimethylarsinic acid (DMA), 42.6; arsenobetaine (AsBe), 61.3; arsenocholine, trimethylarsine oxide, and unidentified arsenics (others), 5.2; and total arsenic (total As), 141.3 microgAs/l. The median creatinine-adjusted values were as follows: AsIII, 3.0; AsV, 0.1; MMA, 2.6; DMA, 35.9; AsBe, 52.1; others 3.5; and total As, 114.9 microgAs/g creatinine. Our findings indicate that DMA and AsBe levels in Japan are much higher than those found in Italian and American studies. It appears that the high levels of DMA and AsBe observed in Japan may be due in part to seafood intake. ACGIH and DFG set the BEI and BAT values for occupational arsenic exposure as 35 microgAs/l and 50 microgAs/l, respectively, using the sum of inorganic arsenic (iAs), MMA, and DMA. In the general Japanese population, the sums of these were above 50 microgAs/l in 115 (55%) samples. We therefore recommend excluding DMA concentration in monitoring of iAs exposure.

Adsorption and desorption characteristics of arsenic onto ceria nanoparticles

PubMed Central

2012-01-01

The rapid increase in the use of engineered nanoparticles [ENPs] has resulted in an increasing concern over the potential impacts of ENPs on the environmental and human health. ENPs tend to adsorb a large variety of toxic chemicals when they are emitted into the environment, which may enhance the toxicity of ENPs and/or adsorbed chemicals. The study was aimed to investigate the adsorption and desorption behaviors of arsenic on ceria NPs in aqueous solution using batch technique. Results show that the adsorption behavior of arsenic on ceria NPs was strongly dependent on pH and independent of ionic strength, indicating that the electrostatic effect on the adsorption of these elements was relatively not important compared to surface chemical reactions. The adsorption isotherms fitted very well to both the Langmuir and Freundlich models. The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) for the adsorption of arsenic were determined at three different temperatures of 283, 303, and 323 K. The adsorption reaction was endothermic, and the process of adsorption was favored at high temperature. The desorption data showed that desorption hysteresis occurred at the initial concentration studied. High adsorption capacity of arsenic on ceria NPs suggests that the synergistic effects of ceria NPs and arsenic on the environmental systems may exist when they are released into the environment. PMID:22269298

Tissue, Dosimetry, Metabolism and Excretion of Pentavalent and Trivalent Dimethylated Arsenic in Mice after Oral Administration

EPA Science Inventory

Dimethylarsinic acid (DMA(V)) is a rat bladder carcinogen and the major urinary metabolite of administered inorganic arsenic in most mammals. This study examined the disposition of pentavalent and trivalent dimethylated arsenic inmice after acute oral administration. Adult fema...

Scoping candidate minerals for stabilization of arsenic-bearing solid residuals.

PubMed

Raghav, Madhumitha; Shan, Jilei; Sáez, A Eduardo; Ela, Wendell P

2013-12-15

Arsenic Crystallization Technology (ACT) is a potentially eco-friendly, effective technology for stabilization of arsenic-bearing solid residuals (ABSRs). The strategy is to convert ABSRs generated by water treatment facilities into minerals with a high arsenic capacity and long-term stability in mature, municipal solid waste landfills. Candidate minerals considered in this study include scorodite, arsenate hydroxyapatites, ferrous arsenates (symplesite-type minerals), tooeleite, and arsenated-schwertmannite. These minerals were evaluated as to ease of synthesis, applicability to use of iron-based ABSRs as a starting material, and arsenic leachability. The Toxicity Characteristic Leaching Procedure (TCLP) was used for preliminary assessment of candidate mineral leaching. Minerals that passed the TCLP and whose synthesis route was promising were subjected to a more aggressive leaching test using a simulated landfill leachate (SLL) solution. Scorodite and arsenate hydroxyapatites were not considered further because their synthesis conditions were not found to be favorable for general application. Tooeleite and silica-amended tooeleite showed high TCLP arsenic leaching and were also not investigated further. The synthesis process and leaching of ferrous arsenate and arsenated-schwertmannite were promising and of these, arsenated-schwertmannite was most stable during SLL testing. The latter two candidate minerals warrant synthesis optimization and more extensive testing. Copyright © 2013 Elsevier B.V. All rights reserved.

Scoping Candidate Minerals for Stabilization of Arsenic-Bearing Solid Residuals

PubMed Central

Raghav, Madhumitha; Shan, Jilei; Sáez, A. Eduardo; Ela, Wendell P.

2014-01-01

Arsenic Crystallization Technology (ACT) is a potentially eco-friendly, effective technology for stabilization of arsenic-bearing solid residuals (ABSRs). The strategy is to convert ABSRs generated by water treatment facilities into minerals with a high arsenic capacity and long-term stability in mature, municipal solid waste landfills. Candidate minerals considered in this study include scorodite, arsenate hydroxyapatites, ferrous arsenates (symplesite-type minerals), tooeleite, and arsenated-schwertmannite. These minerals were evaluated as to ease of synthesis, applicability to use of iron-based ABSRs as a starting material, and arsenic leachability. The Toxicity Characteristic Leaching Procedure (TCLP) was used for preliminary assessment of candidate mineral leaching. Minerals that passed the TCLP and whose synthesis route was promising were subjected to a more aggressive leaching test using a simulated landfill leachate (SLL) solution. Scorodite and arsenate hydroxyapatites were not considered further because their synthesis conditions were not found to be favorable for general application. Tooeleite and silica-amended tooeleite showed high TCLP arsenic leaching and were also not investigated further. The synthesis process and leaching of ferrous arsenate and arsenated-schwertmannite were promising and of these, arsenated-schwertmannite was most stable during SLL testing. The latter two candidate minerals warrant synthesis optimization and more extensive testing. PMID:24231323

Pollution magnet: nano-magnetite for arsenic removal from drinking water.

PubMed

Yavuz, Cafer T; Mayo, J T; Suchecki, Carmen; Wang, Jennifer; Ellsworth, Adam Z; D'Couto, Helen; Quevedo, Elizabeth; Prakash, Arjun; Gonzalez, Laura; Nguyen, Christina; Kelty, Christopher; Colvin, Vicki L

2010-08-01

Arsenic contamination in groundwater is a severe global problem, most notably in Southeast Asia where millions suffer from acute and chronic arsenic poisoning. Removing arsenic from groundwater in impoverished rural or urban areas without electricity and with no manufacturing infrastructure remains a significant challenge. Magnetite nanocrystals have proven to be useful in arsenic remediation and could feasibly be synthesized by a thermal decomposition method that employs refluxing of FeOOH and oleic acid in 1-octadecene in a laboratory setup. To reduce the initial cost of production, $US 2600/kg, and make this nanomaterial widely available, we suggest that inexpensive and accessible "everyday" chemicals be used. Here we show that it is possible to create functional and high-quality nanocrystals using methods appropriate for manufacturing in diverse and minimal infrastructure, even those without electricity. We suggest that the transfer of this knowledge is best achieved using an open source concept.

Speciation analysis of arsenic compounds in seafood by ion chromatography-atomic fluorescence spectrometry

NASA Astrophysics Data System (ADS)

Han, Tingting; Ji, Hongwei; Li, Huixin; Cui, He; Song, Tian; Duan, Xiaojuan; Zhu, Qianlin; Cai, Feng; Zhang, Li

2017-06-01

Ion chromatography-ultra violet-hydride generation-Atomic Florescence Spectrometry was applied to detect 5 arsenic species in seafoods. The arsenic species studied include arsenobetaine (AsB), arsenite (As(III)), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and arsenate (As(V)), which were extracted from samples using 2% formic acid. Gradient elution using 33 mmol L-1 CH3COONH4 and 15 mmol L-1 Na2CO3 with 10 mL CH3CH2OH at pH 8.4 allowed the chromatographic separation of all the species on a Hamilton PRP-X100 anion-exchange column in less than 8 min. In this study, an ultrasound extraction method was used to extract arsenic species from seafood. The extraction efficiency was good and the recoveries from spiked samples were in the range of 72.6%-109%; the precision between sample replicates was higher than 3.6% for all determinations. The detection limits were 3.543 μg L-1 for AsB, 0.426 μg L-1 for As(III), 0.216 μg L-1 for DMA, 0.211 μg L-1 for MMA, and 0.709 μg L-1 for As(V), and the linear coefficients were greater than 0.999. We also developed an application of this method for the determination of arsenic species in bonito, Euphausia superba, and Enteromorpha with satisfactory results. Therefore, it was confirmed that this method was appropriate for the detection of arsenic species in seafood.

Humic acid provenance influence to the adsorption capacity in uranium and thorium removal

NASA Astrophysics Data System (ADS)

Prasetyo, E.

2018-01-01

It is common knowledge that humic acid is organic compound without certain chemical composition since it is derived from different organic materials. Further this raises question whether the different humic acid sample used could lead to different adsorbent properties e.g. adsorption capacity. To address the problem, this paper is aimed to clarify the relation between the provenances of humic acid and synthesized adsorbent properties especially adsorption capacities by quantitative and qualitative functional groups determination including discussion on their effect to the metal ion adsorption mechanism using three humic acid samples. Two commercial samples were derived from recent compost while the other extracted from tertiary carbonaceous mudstone strata.

[Influencing factors and mechanism of arsenic removal during the aluminum coagulation process].

PubMed

Chen, Gui-Xia; Hu, Cheng-Zhi; Zhu, Ling-Feng; Tong, Hua-Qing

2013-04-01

Aluminum coagulants are widely used in arsenic (As) removal during the drinking water treatment process. Aluminium chloride (AlCl3) and polyaluminium chloride (PACl) which contains high content of Al13 were used as coagulants. The effects of aluminum species, pH, humic acid (HA) and coexisting anions on arsenic removal were investigated. Results showed that AlCl3 and PACl were almost ineffective in As(II) removal while the As(V) removal efficiency reached almost 100%. pH was an important influencing factor on the arsenic removal efficiency, because pH influenced the distribution of aluminum species during the coagulation process. The efficiency of arsenic removal by aluminum coagulants was positively correlated with the content of Al13 species. HA and some coexisting anions showed negative impact on arsenic removal because of the competitive adsorption. The negative influence of HA was more pronounced at low coagulant dosages. PO4(3-) and F(-) showed marked influence during arsenic removal, but there was no obvious influence when SiO3(2-), CO3(2-) and SO4(2-) coexisted. The present study would be helpful to direct arsenic removal by enhanced coagulation during the drinking water treatment.

TISSUE DOSIMETRY, METABOLISM AND EXCRETION OF PENTAVALENT AND TRIVALENT DIMETHYLATED ARSENIC IN MICE AFTER ORAL ADMINISTRATION

EPA Science Inventory

Dimethylarsinic acid (DMA(V)) is a rat bladder carcinogen and the major urinary metabolite of inorganic arsenic in most mammals. This study examined the disposition of pentavalent and trivalent dimethylated arsenic in mice after acute oral administration. Adult female mice were...

Microwave-hydrothermal method for the synthesis of composite materials for removal of arsenic from water.

PubMed

Andjelkovic, Ivan; Jovic, Bojan; Jovic, Milica; Markovic, Marijana; Stankovic, Dalibor; Manojlovic, Dragan; Roglic, Goran

2016-01-01

Composite material Zr-doped TiO2, suitable for the removal of arsenic from water, was synthetized with fast and simple microwave-hydrothermal method. Obtained material, Zr-TiO2, had uniform size and composition with zirconium ions incorporated into crystal structure of titanium dioxide. Synthetized composite material had large specific surface area and well-developed micropore and mesopore structure that was responsible for fast adsorption of As(III) and As(V) from water. The influence of pH on the adsorption capacity of arsenic was studied. The kinetics and isotherm experiments were also performed. The treatment of natural water sample containing high concentration of arsenic with composite material Zr-TiO2 was efficient. The concentration of arsenic was reduced to the value recommended by WHO.

Comparison of three sequential extraction procedures for arsenic fractionation in highly polluted sites.

PubMed

Wan, Xiang; Dong, Haochen; Feng, Liu; Lin, Zhijia; Luo, Qiuchen

2017-07-01

Three sequential extraction procedures (SEPs) including Tessier, Rauret, and Shiowatana SEPs, were compared for arsenic fractionation using highly polluted soils. In the definition context of exchangeable, reducible, oxidizable and residual fractions, with similar arsenic recovery and reproducibility, Tessier and Rauret SEPs were comparable to each other, whereas Shiowatana SEP showed higher extraction efficiency in all the first three arsenic fractions, although it might overestimate the reducible arsenic. Pot experiment indicated three SEPs all could provide an estimation of the most bioavailable arsenic fraction, and the application of Shiowatana SEP should be preferred. Accordingly, a case study with Shiowatana SEP for a site near a realgar mine area is conducted. The results show that although arsenic in this area presents predominantly in the stable fractions, the sum of most bioavailable fractions was accounted around 11% of total arsenic, and moreover, about another 10% of the total arsenic, the fourth fraction in Shiowatana SEP is likely to be transferred into bioavailable species under suitable conditions, such as strong acid impact, revealing a real major risk source being formed. The study indicated that Shiowatana should be more suitable for arsenic fractionation to provide valuable information in the framework of risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Association between body mass index and arsenic methylation efficiency in adult women from southwest U.S. and northwest Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez-Rubio, Paulina; Roberge, Jason; Arendell, Leslie

2011-04-15

Human arsenic methylation efficiency has been consistently associated with arsenic-induced disease risk. Interindividual variation in arsenic methylation profiles is commonly observed in exposed populations, and great effort has been put into the study of potential determinants of this variability. Among the factors that have been evaluated, body mass index (BMI) has not been consistently associated with arsenic methylation efficiency; however, an underrepresentation of the upper BMI distribution was commonly observed in these studies. This study investigated potential factors contributing to variations in the metabolism of arsenic, with specific interest in the effect of BMI where more than half of themore » population was overweight or obese. We studied 624 adult women exposed to arsenic in drinking water from three independent populations. Multivariate regression models showed that higher BMI, arsenic (+ 3 oxidation state) methyltransferase (AS3MT) genetic variant 7388, and higher total urinary arsenic were significantly associated with low percentage of urinary arsenic excreted as monomethylarsonic acid (%uMMA) or high ratio between urinary dimethylarsinic acid and uMMA (uDMA/uMMA), while AS3MT genetic variant M287T was associated with high %uMMA and low uDMA/uMMA. The association between BMI and arsenic methylation efficiency was also evident in each of the three populations when studied separately. This strong association observed between high BMI and low %uMMA and high uDMA/uMMA underscores the importance of BMI as a potential arsenic-associated disease risk factor, and should be carefully considered in future studies associating human arsenic metabolism and toxicity.« less

Topical photodynamic therapy with 5-ALA in the treatment of arsenic-induced skin tumors

NASA Astrophysics Data System (ADS)

Karrer, Sigrid; Szeimies, Rolf-Markus; Landthaler, Michael

1995-03-01

A case of a 62-year-old woman suffering from psoriasis who was treated orally with arsenic 25 years ago is reported. The cumulative dose of arsenic trioxide was 800 mg. Since 10 years ago arsenic keratoses, basal cell carcinomas, Bowen's disease and invasive squamous cell carcinomas mainly on her hands and feet have developed, skin changes were clearly a sequence of arsenic therapy. Control of disease was poor, her right little finger had to be amputated. Topical photodynamic therapy with 5-aminolevulinic acid was performed on her right hand. Clinical and histological examinations 6 months after treatment showed an excellent cosmetic result with no signs of tumor residue.

Arsenic bioaccessibility in a soil amended with drinking-water treatment residuals in the presence of phosphorus fertilizer.

PubMed

Sarkar, D; Quazi, S; Makris, K C; Datta, R; Khairom, A

2007-10-01

A laboratory incubation study was conducted to determine the effect of drinking-water treatment residuals (WTRs) on arsenic (As) bioaccessibility and phytoavailability in a poorly As-sorbing soil contaminated with arsenical pesticides and fertilized with triple super phosphate (TSP). The Immokalee soil (a sandy spodosol with minimal As-retention capacity) was amended with 2 WTRs (Al and Fe) at 5 application rates ranging between 0% and 5% wt/wt. Sodium arsenate and TSP were used to spike the soil with 90 mg As kg(-1) and 115 mg P kg(-1), respectively. Bioaccessible As was determined at time 0 (immediately after spiking), and at 6 and 12 months of equilibration using an in vitro gastrointestinal test, and As phytoavailability was measured with a 1-M KC1 extraction test. Arsenic phytoavailability decreased immediately after spiking (20% availability at 5% rate), but only after 6 months for the Al-WTR- and the Fe-WTR-amended soil, respectively. Arsenic bioaccessibility simulated for the stomach and intestine phases showed that the Fe-WTR was more effective than the Al-WTR in resisting the harsh acidic conditions of the human stomach, thus preventing As release. Both the phytoavailable As and the bioaccessible As were significantly correlated (p < 0.001) for soil spiked with either Al- or Fe-WTR. Both WTRs were able to decrease soil As bioaccessibility irrespective of the presence or absence of P, which was added as TSP. Results indicate the potential of WTRs in immobilizing As in contaminated soils fertilized with P, thereby minimizing soil As bioaccessibility and phytoavailability.

ARSENIC (+3 OXIDATION STATE) METHYLTRANSFERASE AND THE METHYLATION OF ARSENICALS

EPA Science Inventory

Metabolic conversion of inorganic arsenic into methylated products is a multistep process that yields mono, di, and trimethylated arsenicals. In recent years, it has become apparent that formation of methylated metabolites of inorganic arsenic is not necessarily a detoxification...

Removing arsenic from groundwater in Cambodia using high performance iron adsorbent.

PubMed

Kang, Y; Takeda, R; Nada, A; Thavarith, L; Tang, S; Nuki, K; Sakurai, K

2014-09-01

In Cambodia, groundwater has been contaminated with arsenic, and purification of the water is an urgent issue. From 2010 to 2012, an international collaborative project between Japan and Cambodia for developing arsenic-removing technology from well water was conducted and supported by the foundation of New Energy and Industrial Technology Development Organization, Japan. Quality of well water was surveyed in Kandal, Prey Veng, and Kampong Cham Provinces, and a monitoring trial of the arsenic removal equipment using our patented amorphous iron (hydr)oxide adsorbent was performed. Of the 37 wells surveyed, arsenic concentration of 24 exceeded the Cambodian guideline value (50 μg L(-1)), and those of 27 exceeded the WHO guideline for drinking water (10 μg L(-1)). Levels of arsenic were extremely high in some wells (>1,000-6,000 μg L(-1)), suggesting that arsenic pollution of groundwater is serious in these areas. Based on the survey results, 16 arsenic removal equipments were installed in six schools, three temples, two health centers, four private houses, and one commune office. Over 10 months of monitoring, the average arsenic concentrations of the treated water were between 0 and 10 μg L(-1) at four locations, 10-50 μg L(-1) at eight locations, and >50 μg L(-1) at four locations. The arsenic removal rate ranged in 83.1-99.7%, with an average of 93.8%, indicating that the arsenic removal equipment greatly lower the risk of arsenic exposure to the residents. Results of the field trial showed that As concentration of the treated water could be reduced to <10 µg L(-1) by managing the As removal equipment properly, suggesting that the amorphous iron (hydr)oxide adsorbent has high adsorbing capacity for As not only in the laboratory environment but also in the field condition. This is one of the succeeding As removal techniques that could reduce As concentration of water below the WHO guideline value for As in situ.

Characterization of intracellular inclusions in the urothelium of mice exposed to inorganic arsenic.

PubMed

Dodmane, Puttappa R; Arnold, Lora L; Muirhead, David E; Suzuki, Shugo; Yokohira, Masanao; Pennington, Karen L; Dave, Bhavana J; Lu, Xiufen; Le, X Chris; Cohen, Samuel M

2014-01-01

Inorganic arsenic (iAs) is a known human carcinogen at high exposures, increasing the incidences of urinary bladder, skin, and lung cancers. In most mammalian species, ingested iAs is excreted mainly through urine primarily as dimethylarsinic acid (DMA(V)). In wild-type (WT) mice, iAs, DMA(V), and dimethylarsinous acid (DMA(III)) exposures induce formation of intramitochondrial urothelial inclusions. Arsenite (iAs(III)) also induced intranuclear inclusions in arsenic (+3 oxidation state) methyltransferase knockout (As3mt KO) mice. The arsenic-induced formation of inclusions in the mouse urothelium was dose and time dependent. The inclusions do not occur in iAs-treated rats and do not appear to be related to arsenic-induced urothelial cytotoxicity. Similar inclusions in exfoliated urothelial cells from humans exposed to iAs have been incorrectly identified as micronuclei. We have characterized the urothelial inclusions using transmission electron microscopy (TEM), DNA-specific 4',6-diamidino-2-phenylindole (DAPI), and non-DNA-specific Giemsa staining and determined the arsenical content. The mouse inclusions stained with Giemsa but not with the DAPI stain. Analysis of urothelial mitochondrial- and nuclear-enriched fractions isolated from WT (C57BL/6) and As3mt KO mice exposed to arsenate (iAs(V)) for 4 weeks showed higher levels of iAs(V) in the treated groups. iAs(III) was the major arsenical present in the enriched nuclear fraction from iAs(V)-treated As3mt KO mice. In conclusion, the urothelial cell inclusions induced by arsenicals appear to serve as a detoxifying sequestration mechanism similar to other metals, and they do not represent micronuclei.

Arsenic removal methods for drinking water in the developing countries: technological developments and research needs.

PubMed

Kabir, Fayzul; Chowdhury, Shakhawat

2017-11-01

Arsenic pollution of drinking water is a concern, particularly in the developing countries. Removal of arsenic from drinking water is strongly recommended. Despite the availability of efficient technologies for arsenic removal, the small and rural communities in the developing countries are not capable of employing most of these technologies due to their high cost and technical complexity. There is a need for the "low-cost" and "easy to use" technologies to protect the humans in the arsenic affected developing countries. In this study, arsenic removal technologies were summarized and the low-cost technologies were reviewed. The advantages and disadvantages of these technologies were identified and their scopes of applications and improvements were investigated. The costs were compared in context to the capacity of the low-income populations in the developing countries. Finally, future research directions were proposed to protect the low-income populations in the developing countries.

Diet and toenail arsenic concentrations in a New Hampshire population with arsenic-containing water

PubMed Central

2013-01-01

Background Limited data exist on the contribution of dietary sources of arsenic to an individual’s total exposure, particularly in populations with exposure via drinking water. Here, the association between diet and toenail arsenic concentrations (a long-term biomarker of exposure) was evaluated for individuals with measured household tap water arsenic. Foods known to be high in arsenic, including rice and seafood, were of particular interest. Methods Associations between toenail arsenic and consumption of 120 individual diet items were quantified using general linear models that also accounted for household tap water arsenic and potentially confounding factors (e.g., age, caloric intake, sex, smoking) (n = 852). As part of the analysis, we assessed whether associations between log-transformed toenail arsenic and each diet item differed between subjects with household drinking water arsenic concentrations <1 μg/L versus ≥1 μg/L. Results As expected, toenail arsenic concentrations increased with household water arsenic concentrations. Among the foods known to be high in arsenic, no clear relationship between toenail arsenic and rice consumption was detected, but there was a positive association with consumption of dark meat fish, a category that includes tuna steaks, mackerel, salmon, sardines, bluefish, and swordfish. Positive associations between toenail arsenic and consumption of white wine, beer, and Brussels sprouts were also observed; these and most other associations were not modified by exposure via water. However, consumption of two foods cooked in water, beans/lentils and cooked oatmeal, was more strongly related to toenail arsenic among those with arsenic-containing drinking water (≥1 μg/L). Conclusions This study suggests that diet can be an important contributor to total arsenic exposure in U.S. populations regardless of arsenic concentrations in drinking water. Thus, dietary exposure to arsenic in the US warrants consideration as a potential

Diet and toenail arsenic concentrations in a New Hampshire population with arsenic-containing water.

PubMed

Cottingham, Kathryn L; Karimi, Roxanne; Gruber, Joann F; Zens, M Scot; Sayarath, Vicki; Folt, Carol L; Punshon, Tracy; Morris, J Steven; Karagas, Margaret R

2013-11-16

Limited data exist on the contribution of dietary sources of arsenic to an individual's total exposure, particularly in populations with exposure via drinking water. Here, the association between diet and toenail arsenic concentrations (a long-term biomarker of exposure) was evaluated for individuals with measured household tap water arsenic. Foods known to be high in arsenic, including rice and seafood, were of particular interest. Associations between toenail arsenic and consumption of 120 individual diet items were quantified using general linear models that also accounted for household tap water arsenic and potentially confounding factors (e.g., age, caloric intake, sex, smoking) (n = 852). As part of the analysis, we assessed whether associations between log-transformed toenail arsenic and each diet item differed between subjects with household drinking water arsenic concentrations <1 μg/L versus ≥1 μg/L. As expected, toenail arsenic concentrations increased with household water arsenic concentrations. Among the foods known to be high in arsenic, no clear relationship between toenail arsenic and rice consumption was detected, but there was a positive association with consumption of dark meat fish, a category that includes tuna steaks, mackerel, salmon, sardines, bluefish, and swordfish. Positive associations between toenail arsenic and consumption of white wine, beer, and Brussels sprouts were also observed; these and most other associations were not modified by exposure via water. However, consumption of two foods cooked in water, beans/lentils and cooked oatmeal, was more strongly related to toenail arsenic among those with arsenic-containing drinking water (≥1 μg/L). This study suggests that diet can be an important contributor to total arsenic exposure in U.S. populations regardless of arsenic concentrations in drinking water. Thus, dietary exposure to arsenic in the US warrants consideration as a potential health risk.

Arsenic speciation and trace element analysis of the volcanic río Agrio and the geothermal waters of Copahue, Argentina.

PubMed

Farnfield, Hannah R; Marcilla, Andrea L; Ward, Neil I

2012-09-01

Surface water originating from the Copahue volcano crater-lake was analysed for total arsenic and four arsenic species: arsenite (iAs(III)), arsenate (iAs(V)), monomethylarsonic acid (MA(V)) and dimethylarsinic acid (DMA(V)) and other trace elements (Fe, Mn, V, Cr, Ni, Zn). A novel in-field technique for the preconcentration and separation of four arsenic species was, for the first time, used for the analysis of geothermal and volcanic waters. Total arsenic levels along the río Agrio ranged from <0.2-3783 μg/l As(T). The highest arsenic levels were recorded in the el Vertedero spring (3783 μg/l As(T)) on the flank of the Copahue volcano, which feeds the acidic río Agrio. Arsenite (H(3)AsO(3)) predominated along the upper río Agrio (78.9-81.2% iAs(III)) but the species distribution changed at lago Caviahue and arsenate (H(2)AsO(4)(-)) became the main species (51.4-61.4% iAs(V)) up until Salto del Agrio. The change in arsenic species is potentially a result of an increase in redox potential and the formation of iron-based precipitates. Arsenic speciation showed a statistically significant correlation with redox potential (r=0.9697, P=0.01). Both total arsenic and arsenic speciation displayed a statistically significant correlation with vanadium levels along the river (r=0.9961, P=0.01 and r=0.8488, P=0.05, respectively). This study highlights that chemical speciation analysis of volcanic waters is important in providing ideas on potential chemical toxicity. Furthermore there is a need for further work evaluating how arsenic (and other trace elements), released in volcanic and geothermal streams/vents, impacts on both biota and humans (via exposure in thermal pools or consuming commercial drinking water). Copyright © 2012 Elsevier B.V. All rights reserved.

Determination and identification of hydrophilic and hydrophobic arsenic species in methanol extract of fresh cod liver by RP-HPLC with simultaneous ICP-MS and ESI-Q-TOF-MS detection.

PubMed

Arroyo-Abad, Uriel; Lischka, Susanne; Piechotta, Christian; Mattusch, Jürgen; Reemtsma, Thorsten

2013-12-01

The present study was focused on the determination and identification of arsenic species in methanolic extracts of cod liver. Arsenic species were fractionated and the fractions analysed by RP-HPLC-ICP-MS coupled with ESI-Q-TOF-MS. The total concentration of arsenic in the fresh cod liver was analysed by ICP-MS to be 1.53±0.02 mg As kg(-1)w.w. and the extraction recovery was ca. 100% and the column recovery >93%. Besides polar inorganic and methylated arsenic species (>70%) more hydrophobic arsenic-containing fatty acids and hydrocarbons occurred. Based on the mass spectrometric data proposals for molecular structures were elaborated for 20 of the organic As species included 10 arsenic-containing fatty acids (AsFA) and an arsenic-containing hydrocarbon (AsHC) mentioned for the first time in fresh cod liver. Arsenobetaine was found as main water-soluble arsenic compound in cod liver followed by higher molecular mass arsenic-containing fatty acids and hydrocarbons. Copyright © 2013 Elsevier Ltd. All rights reserved.

Estimation of Inorganic Arsenic Exposure in Populations With Frequent Seafood Intake: Evidence From MESA and NHANES

PubMed Central

Jones, Miranda R.; Tellez-Plaza, Maria; Vaidya, Dhananjay; Grau, Maria; Francesconi, Kevin A.; Goessler, Walter; Guallar, Eliseo; Post, Wendy S.; Kaufman, Joel D.; Navas-Acien, Ana

2016-01-01

The sum of urinary inorganic arsenic (iAs) and methylated arsenic (monomethylarsonate and dimethylarsinate (DMA)) species is the main biomarker of iAs exposure. Assessing iAs exposure, however, is difficult in populations with moderate-to-high seafood intakes. In the present study, we used subsamples from the Multi-Ethnic Study of Atherosclerosis (2000–2002) (n = 310) and the 2003–2006 National Health and Nutrition Examination Survey (n = 1,175). We calibrated urinary concentrations of non–seafood-derived iAs, DMA, and methylarsonate, as well as the sum of inorganic and methylated arsenic species, in the Multi-Ethnic Study of Atherosclerosis and of DMA in the National Health and Nutrition Examination Survey by regressing their original concentrations by arsenobetaine and extracting model residuals. To confirm that calibrated biomarkers reflected iAs exposure but not seafood intake, we compared urinary arsenic concentrations by levels of seafood and rice intakes. Self-reported seafood intakes, estimated n-3 polyunsaturated fatty acid levels, and measured n-3 polyunsaturated fatty acid levels were positively associated with the original urinary arsenic biomarkers. Using the calibrated arsenic biomarkers, we found a marked attenuation of the associations with self-reported seafood intake and estimated or measured n-3 fatty acids, whereas associations with self-reported rice intake remained similar. Our residual-based method provides estimates of iAs exposure and metabolism for each participant that no longer reflect seafood intake and can facilitate research about low-to-moderate levels of iAs exposure in populations with high seafood intakes. PMID:27702745

Positive selection of AS3MT to arsenic water in Andean populations

PubMed Central

Eichstaedt, Christina A.; Antao, Tiago; Cardona, Alexia; Pagani, Luca; Kivisild, Toomas; Mormina, Maru

2016-01-01

Arsenic is a carcinogen associated with skin lesions and cardiovascular diseases. The Colla population from the Puna region in Northwest Argentinean is exposed to levels of arsenic in drinking water exceeding the recommended maximum by a factor of 20. Yet, they thrive in this challenging environment since thousands of years and therefore we hypothesize strong selection signatures in genes involved in arsenic metabolism. We analyzed genome-wide genotype data for 730,000 loci in 25 Collas, considering 24 individuals of the neighbouring Calchaquíes and 24 Wichí from the Gran Chaco region in the Argentine province of Salta as control groups. We identified a strong signal of positive selection in the main arsenic methyltransferase AS3MT gene, which has been previously associated with lower concentrations of the most toxic product of arsenic metabolism monomethylarsonic acid. This study confirms recent studies reporting selection signals in the AS3MT gene albeit using different samples, tests and control populations. PMID:26366667

INTERINDIVIDUAL VARIATION IN THE METABOLISM OF ARSENIC IN HUMAN HEPATOCYTES

EPA Science Inventory

The liver is the major site for the enzymatic methylation of inorganic arsenic (iAs) in humans. Primary cultures of normal human hepatocytes isolated from tissue obtained at surgery or from donor livers have been used to study interindividual variation in the capacity of live...

Evaluation of the ability of arsenic species to traverse cell membranes by simple diffusion using octanol-water and liposome-water partition coefficients.

PubMed

Chávez-Capilla, Teresa; Maher, William; Kelly, Tamsin; Foster, Simon

2016-11-01

Arsenic metabolism in living organisms is dependent on the ability of different arsenic species to traverse biological membranes. Simple diffusion provides an alternative influx and efflux route to mediated transport mechanisms that can increase the amount of arsenic available for metabolism in cells. Using octanol-water and liposome-water partition coefficients, the ability of arsenous acid, arsenate, methylarsonate, dimethylarsinate, thio-methylarsonate, thio-dimethylarsinic acid, arsenotriglutathione and monomethylarsonic diglutathione to diffuse through the lipid bilayer of cell membranes was investigated. Molecular modelling of arsenic species was used to explain the results. All arsenic species with the exception of arsenate, methylarsonate and thio-methylarsonate were able to diffuse through the lipid bilayer of liposomes, with liposome-water partition coefficients between 0.04 and 0.13. Trivalent arsenic species and thio-pentavalent arsenic species showed higher partition coefficients, suggesting that they can easily traverse cell membranes by passive simple diffusion. Given the higher toxicity of these species compared to oxo-pentavalent arsenic species, this study provides evidence supporting the risk associated with human exposure to trivalent and thio-arsenic species. Copyright © 2016. Published by Elsevier B.V.

Different low-molecular-mass organic acids specifically control leaching of arsenic and lead from contaminated soil

NASA Astrophysics Data System (ADS)

Ash, Christopher; Tejnecký, Václav; Borůvka, Luboš; Drábek, Ondřej

2016-04-01

Low-molecular-mass organic acids (LMMOA) are of key importance for mobilisation and fate of metals in soil, by functioning as ligands that increase the amount of dissolved metal in solution or by dissociation of metal binding minerals. Column leaching experiments were performed on soil polluted with As and Pb, in order to determine the specificity of LMMOA related release for individual elements, at varying organic acid concentrations. Acetic, citric and oxalic acids were applied in 12 h leaching experiments over a concentration range (0.5-25 mM) to soil samples that represent organic and mineral horizons. The leaching of As followed the order: oxalic > citric > acetic acid in both soils. Arsenic leaching was attributed primarily to ligand-enhanced dissolution of mineral oxides followed by As released into solution, as shown by significant correlation between oxalic and citric acids and content of Al and Fe in leaching solutions. Results suggest that subsurface mineral soil layers are more vulnerable to As toxicity. Leaching of Pb from both soils followed the order: citric > oxalic > acetic acid. Mineral soil samples were shown to be more susceptible to leaching of Pb than samples characterised by a high content of organic matter. The leaching efficiency of citric acid was attributed to formation of stable complexes with Pb ions, which other acids are not capable of. Results obtained in the study are evidence that the extent of As and Pb leaching in contaminated surface and subsurface soil depends significantly on the types of carboxylic acid involved. The implications of the type of acid and the specific element that can be mobilised become increasingly significant where LMMOA concentrations are highest, such as in rhizosphere soil.

Factors Affecting Arsenic Methylation in Arsenic-Exposed Humans: A Systematic Review and Meta-Analysis.

PubMed

Shen, Hui; Niu, Qiang; Xu, Mengchuan; Rui, Dongsheng; Xu, Shangzhi; Feng, Gangling; Ding, Yusong; Li, Shugang; Jing, Mingxia

2016-02-06

Chronic arsenic exposure is a critical public health issue in many countries. The metabolism of arsenic in vivo is complicated because it can be influenced by many factors. In the present meta-analysis, two researchers independently searched electronic databases, including the Cochrane Library, PubMed, Springer, Embase, and China National Knowledge Infrastructure, to analyze factors influencing arsenic methylation. The concentrations of the following arsenic metabolites increase (p< 0.000001) following arsenic exposure: inorganic arsenic (iAs), monomethyl arsenic (MMA), dimethyl arsenic (DMA), and total arsenic. Additionally, the percentages of iAs (standard mean difference (SMD): 1.00; 95% confidence interval (CI): 0.60-1.40; p< 0.00001) and MMA (SMD: 0.49; 95% CI: 0.21-0.77; p = 0.0006) also increase, while the percentage of DMA (SMD: -0.57; 95% CI: -0.80--0.31; p< 0.0001), primary methylation index (SMD: -0.57; 95% CI: -0.94--0.20; p = 0.002), and secondary methylation index (SMD: -0.27; 95% CI: -0.46--0.90; p = 0.004) decrease. Smoking, drinking, and older age can reduce arsenic methylation, and arsenic methylation is more efficient in women than in men. The results of this analysis may provide information regarding the role of arsenic oxidative methylation in the arsenic poisoning process.

Effects of arsenic on adipocyte metabolism: Is arsenic an obesogen?

PubMed

Ceja-Galicia, Zeltzin A; Daniel, Alberto; Salazar, Ana María; Pánico, Pablo; Ostrosky-Wegman, Patricia; Díaz-Villaseñor, Andrea

2017-09-05

The environmental obesogen model proposes that in addition to a high-calorie diet and diminished physical activity, other factors such as environmental pollutants and chemicals are involved in the development of obesity. Although arsenic has been recognized as a risk factor for Type 2 Diabetes with a specific mechanism, it is still uncertain whether arsenic is also an obesogen. The impairment of white adipose tissue (WAT) metabolism is crucial in the onset of obesity, and distinct studies have evaluated the effects of arsenic on it, however only in some of them for obesity-related purposes. Thus, the known effects of arsenic on WAT/adipocytes were integrated based on the diverse metabolic and physiological processes that occur in WAT and are altered in obesity, specifically: adipocyte growth, adipokine secretion, lipid metabolism, and glucose metabolism. The currently available information suggests that arsenic can negatively affect WAT metabolism, resulting in arsenic being a potential obesogen. Copyright © 2017 Elsevier B.V. All rights reserved.

Selenite restores Pax6 expression in neuronal cells of chronically arsenic-exposed Golden Syrian hamsters.

PubMed

Aguirre-Vázquez, Alain; Sampayo-Reyes, Adriana; González-Escalante, Laura; Hernández, Alba; Marcos, Ricard; Castorena-Torres, Fabiola; Lozano-Garza, Gerardo; Taméz-Guerra, Reyes; de León, Mario Bermúdez

2017-01-01

Arsenic is a worldwide environmental pollutant that generates public health concerns. Various types of cancers and other diseases, including neurological disorders, have been associated with human consumption of arsenic in drinking water. At the molecular level, arsenic and its metabolites have the capacity to provoke genome instability, causing altered expression of genes. One such target of arsenic is the Pax6 gene that encodes a transcription factor in neuronal cells. The aim of this study was to evaluate the effect of two antioxidants, α-tocopheryl succinate (α-TOS) and sodium selenite, on Pax6 gene expression levels in the forebrain and cerebellum of Golden Syrian hamsters chronically exposed to arsenic in drinking water. Animals were divided into six groups. Using quantitative real-time reverse transcriptase (RT)-PCR analysis, we confirmed that arsenic downregulates Pax6 expression in nervous tissues by 53 ± 21% and 32 ± 7% in the forebrain and cerebellum, respectively. In the presence of arsenic, treatment with α-TOS did not modify Pax6 expression in nervous tissues; however, sodium selenite completely restored Pax6 expression in the arsenic-exposed hamster forebrain, but not the cerebellum. Although our results suggest the use of selenite to restore the expression of a neuronal gene in arsenic-exposed animals, its use and efficacy in the human population require further studies.

Mechanism of erythrocyte death in human population exposed to arsenic through drinking water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Debabrata; Banerjee, Mayukh; Sen, Gargi

2008-07-01

Arsenic contamination in drinking water is one of the biggest natural calamities, which has become an imperative threat to human health throughout the world. Abbreviation of erythrocyte lifespan leading to the development of anemia is a common sequel in arsenic exposed population. This study was undertaken to explore the mechanism of cell death in human erythrocytes during chronic arsenic exposure. Results revealed transformation of smooth discoid red cells into evaginated echinocytic form in the exposed individuals. Further distortion converted reversible echinocytes to irreversible spheroechinocytes. Arsenic toxicity increased membrane microviscosity along with an elevation of cholesterol/phospholipid ratio, which hampered the flexibilitymore » of red cell membrane and made them less deformable. Significant increase in the binding of merocyanine 540 with erythrocyte membrane due to arsenic exposure indicated disruption of lipid packing in the outer leaflet of the cell membrane resulting from altered transbilayer phospholipid asymmetry. Arsenic induced eryptosis was characterized by cell shrinkage and exposure of phosphatidylserine at the cell surface. Furthermore, metabolic starvation with depletion of cellular ATP triggered apoptotic removal of erythrocytes from circulation. Significant decrease in reduced glutathione content indicating defective antioxidant capacity was coupled with enhancement of malondialdehyde and protein carbonyl levels, which pointed to oxidative damage to erythrocyte membrane. Arsenic toxicity intervened into red cell membrane integrity eventually leading to membrane destabilization and hemoglobin release. The study depicted the involvement of both erythrophagocytosis and hemolysis in the destruction of human erythrocytes during chronic arsenic exposure.« less

Arsenic removal from water

DOEpatents

Moore, Robert C [Edgewood, NM; Anderson, D Richard [Albuquerque, NM

2007-07-24

Methods for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical methods for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A method for continuous removal of arsenic from water is provided. Also provided is a method for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

Multiple transformation pathways of p-arsanilic acid to inorganic arsenic species in water during UV disinfection.

PubMed

Li, Suqi; Xu, Jing; Chen, Wei; Yu, Yingtan; Liu, Zizheng; Li, Jinjun; Wu, Feng

2016-09-01

p-Arsanilic acid (p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth. The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV-Vis light excitation. This work examined the initial rate and efficiency of p-ASA phototransformation under UV-C disinfection lamp. Several factors influencing p-ASA phototransformation, namely, pH, initial concentration, temperature, as well as the presence of NaCl, NH4(+), and humic acid, were investigated. Quenching experiments and LC-MS were performed to investigate the mechanism of p-ASA phototransformation. Results show that p-ASA was decomposed to inorganic arsenic (including As(III) and As(V)) and aromatic products by UV-C light through direct photolysis and indirect oxidation. The oxidation efficency of p-ASA by direct photosis was about 32%, and those by HO and (1)O2 were 19% and 49%, respectively. Cleavage of the arsenic-benzene bond through direct photolysis, HO oxidation or (1)O2 oxidation results in simultaneous formation of inorganic As(III), As(IV), and As(V). Inorganic As(III) is oxidized to As(IV) and then to As(V) by (1)O2 or HO. As(IV) can undergo dismutation or simply react with oxygen to produce As(V) as well. Reactions of the organic moieties of p-ASA produce aniline, aminophenol and azobenzene derivatives as main products. The photoconvertible property of p-ASA implies that UV disinfection of wastewaters from poultry and swine farms containing p-ASA poses a potential threat to the ecosystem, especially agricultural environments. Copyright © 2016. Published by Elsevier B.V.

Arsenic Mobilization Influenced By Iron Reduction And Sulfidogenesis Under Dynamic Flow

NASA Astrophysics Data System (ADS)

Kocar, B. D.; Stewart, B. D.; Herbel, M.; Fendorf, S.

2004-12-01

Sulfidogenesis and iron reduction are ubiquitous processes that occur in a variety of anoxic subsurface and surface environments, which profoundly impact the cycling of arsenic. Of the iron (hydr)oxides, ferrihydrite possesses one of the highest capacities to retain arsenic, and is globally distributed within soils and sediments. Upon dissimilatory iron reduction, ferrihydrite may transform to lower surface area minerals, such as goethite and magnetite, which decreases arsenic retention, thus enhancing its transport. Here we examine how arsenic retained on ferrihydrite is mobilized under dynamic flow in the presence of Sulfurosprillum barnesii strain SES-3, a bacteria capable of reducing both As(V) and Fe(III). Ferrihydrite coated sands, loaded with 150 mg kg-1 As(V), were inoculated with S. barnesii, packed into a column and reacted with a synthetic groundwater solution. Within several days after initiation of flow, the concentration of arsenic in the column effluent increased dramatically coincident with the mineralogical transformation of ferrihydrite and As(V) reduction to As(III). Following the initial pulse of arsenic, effluent concentration then declined to less than 10 μ M. Thus, arsenic release into the aqueous phase is contingent upon the incongruent reduction of As(V) and Fe(III) as mediated by biological activity. Reaction of abiotically or biotically generated dissolved sulfide with iron (hydr)oxides may have a dramatic influence on the fate of arsenic within surface and subsurface environments. Accordingly, we examined the reaction of dissolved bisulfide and iron (hydr)oxide complexed with arsenic in both batch and column systems. Low ratios of sulfide to iron in batch reaction systems result in the formation of elemental sulfur and concomitant arsenic release from the iron (hydr)oxide surface. High sulfide to iron ratios, in contrast, appear to favor the formation of iron and arsenic sulfides. Our findings demonstrate that iron (hydr)oxides may

Arsenic and fluoride in the groundwater of Mexico.

PubMed

Armienta, M A; Segovia, N

2008-08-01

Concentrations of arsenic and fluoride above Mexican drinking water standards have been detected in aquifers of various areas of Mexico. This contamination has been found to be mainly caused by natural sources. However, the specific processes releasing these toxic elements into groundwater have been determined in a few zones only. Many studies, focused on arsenic-related health effects, have been performed at Comarca Lagunera in northern México. High concentrations of fluoride in water were also found in this area. The origin of the arsenic there is still controversial. Groundwater in active mining areas has been polluted by both natural and anthropogenic sources. Arsenic-rich minerals contaminate the fractured limestone aquifer at Zimapán, Central México. Tailings and deposits smelter-rich fumes polluted the shallow granular aquifer. Arsenic contamination has also been reported in the San Antonio-El Triunfo mining zone, southern Baja California, and Santa María de la Paz, in San Luis Potosí state. Even in the absence of mining activities, hydrogeochemistry and statistical techniques showed that arsenopyrite oxidation may also contaminate water, as in the case of the Independencia aquifer in the Mexican Altiplano. High concentrations of arsenic have also been detected in geothermal areas like Los Azufres, Los Humeros, and Acoculco. Prevalence of dental fluorosis was revealed by epidemiological studies in Aguascalientes and San Luis Potosí states. Presence of fluoride in water results from dissolution of acid-volcanic rocks. In Mexico, groundwater supplies most drinking water. Current knowledge and the geology of Mexico indicate the need to include arsenic and fluoride determinations in groundwater on a routine basis, and to develop interdisciplinary studies to assess the contaminant's sources in all enriched areas.

Differences in Urinary Arsenic Metabolites between Diabetic and Non-Diabetic Subjects in Bangladesh

PubMed Central

Nizam, Saika; Kato, Masashi; Yatsuya, Hiroshi; Khalequzzaman, Md.; Ohnuma, Shoko; Naito, Hisao; Nakajima, Tamie

2013-01-01

Ingestion of inorganic arsenic (iAs) is considered to be related to the development of diabetes mellitus. In order to clarify the possible differences in the metabolism in diabetics, we measured urinary iAs metabolites in diabetic cases and non-diabetic control subjects in Faridpur, an arsenic-contaminated area in Bangladesh. Physician-diagnosed type 2 diabetic cases (140 persons) and non-diabetic controls (180 persons) were recruited. Drinking water and spot urine samples were collected. Mean concentrations of total arsenic in drinking water did not differ between cases (85.1 μg/L) and controls (85.8 μg/L). The percentage of urinary iAs (iAs%) was significantly lower in cases (8.6%) than in controls (10.4%), while that of dimethylarsinic acid (DMA%) was higher in cases (82.6%) than in controls (79.9%). This may have been due to the higher secondary methylation index (SMI) in the former (11.6) rather than the latter (10.0). Adjusting for matching factors (sex and unions), and the additional other covariates (age and water arsenic) significantly attenuated the differences in iAs%, SMI, and DMA%, respectively, though the difference in monomethylarsonic acid% was newly significant in the latter adjustment. Our study did not suggest any significant differences in urinary arsenic metabolites between diabetic and non-diabetic subjects. PMID:23481591

In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Xianjun; Wang, Yanxin; Pi, Kunfu

In situ arsenic removal from groundwater by an iron coating method has great potential to be a cost effective and simple groundwater remediation technique, especially in rural and remote areas where groundwater is used as the main source of drinking water. The in situ arsenic removal technique was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions., Its effectiveness was then evaluated in an actual high-arsenic groundwater environment. The mechanism of arsenic removal by the iron coating was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, an electron microprobe, and Fourier transformationmore » infrared spectroscopy. A 4-step alternative cycle aquifer iron coating method was developed. A continuous injection of 5 mmol/L FeSO4 and 2.5 mmol/L NaClO for 96 hours can create a uniform coating of crystalline goethite on the surface of quartz sand in the columns without causing clogging. At a flow rate of 0.45 cm/min of the injection reagents (vi), the time for arsenic (as Na2HAsO4) to pass through the iron-coated quartz sand column was approximately 35 hours, which was much longer than that for tracer fluorescein sodium (approximately 2 hours). The retardation factor of arsenic was 23, and its adsorption capacity was 0.11 mol As per mol Fe, leading to an excellent arsenic removal. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As (V) and Fe (II) reagents. When the arsenic content in the groundwater was 233 μg/L, the aqueous phase arsenic was completely removed with an arsenic adsorption of 0.05 mol As per mol Fe. Arsenic fixation resulted from a process of adsorption/co-precipitation, in which arsenic and iron likely formed the arsenic-bearing iron mineral phases with poor crystallinity by way of bidentate binuclear complexes. Thus, the high arsenic removal efficiency of the technique likely resulted from

Synthesis and Characterization of Arsenolipids: Naturally Occurring Arsenic Compounds in Fish and Algae

PubMed Central

2014-01-01

Arsenic-containing lipids (arsenolipids) are natural products present in fish and algae. Because these compounds occur in foods, there is considerable interest in their human toxicology. We report the synthesis and characterization of seven arsenic-containing lipids, including six natural products. The compounds comprise dimethylarsinyl groups attached to saturated long-chain hydrocarbons (three compounds), saturated long-chain fatty acids (two compounds), and monounsaturated long chain fatty acids (two compounds). The arsenic group was introduced through sodium dimethylarsenide or bis(dimethylarsenic) oxide. The latter route provided higher and more reproducible yields, and consequently, this pathway was followed to synthesize six of the seven compounds. Mass spectral properties are described to assist in the identification of these compounds in natural samples. The pure synthesized arsenolipids will be used for in vitro experiments with human cells to test their uptake, biotransformation, and possible toxic effects. PMID:24683287

Novel, bio-based, photoactive arsenic sorbent: TiO₂-impregnated chitosan bead.

PubMed

Miller, Sarah M; Zimmerman, Julie B

2010-11-01

A novel sorbent for arsenic, TiO(2)-impregnated chitosan bead (TICB), has been synthesized and successfully tested. Kinetic plots, pH dependence, isotherm data, and bead morphology are reported. Equilibrium is achieved after 185 h in batch experiments with exposure to UV light. The TICB system performs similarly to the mass equivalent of neat TiO(2) nanopowder. The point of zero charge (pzc) for TICB was determined to be 7.25, and as with other TiO(2)-based arsenic removal technologies, the optimal pH range for sorption is below this pH(pzc). Without exposure to UV light, TICB removes 2198 μg As(III)/g TICB and 2050 μg As(V)/g TICB. With exposure to UV light, TICB achieves photo-oxidation of As(III) to As(V), the less toxic and more easily sequestered arsenic form. UV irradiation also results in enhanced arsenic removal, reaching sorption capacities of 6400 μg As/g TICB and 4925 μg As/g TICB, where arsenic is initially added as As(III) and As(V), respectively. Because the TICB system obviates filtration post-treatment, TICB is superior to TiO(2) nanopowder from the perspective of implementation for decentralized water treatment. Copyright © 2010 Elsevier Ltd. All rights reserved.

Direct comparison of XAFS spectroscopy and sequential extraction for arsenic speciation in coal

USGS Publications Warehouse

Huggins, Frank E.; Huffman, G.P.; Kolker, A.; Mroczkowski, S.; Palmer, C.A.; Finkelman, R.B.

2000-01-01

The speciation of arsenic in an Ohio bituminous coal and a North Dakota lignite has been examined by the complementary methods of arsenic XAFS spectroscopy and sequential extraction by aqueous solutions of ammonium acetate, HCl, HF, and HNO3. In order to facilitate a more direct comparison of the two methods, the arsenic XAFS spectra were obtained from aliquots of the coal prepared after each stage of the leaching procedure. For the aliquots, approximately linear correlations (r2 > 0.98 for the Ohio coal, > 0.90 for the ND lignite) were observed between the height of the edge-step in the XAFS analysis and the concentration of arsenic measured by instrumental neutron activation analysis. Results from the leaching sequence indicate that there are two major arsenic forms present in both coals; one is removed by leaching with HCl and the other by HNO3. Whereas the XAFS spectral signatures of the arsenic leached by HCl are compatible with arsenate for both coals, the arsenic leached by HNO3 is identified as arsenic associated with pyrite for the Ohio coal and as an As3+ species for the North Dakota lignite. Minor arsenate forms persist in both coals after the final leaching with nitric acid. The arsenate forms extracted in HCl are believed to be oxidation products derived from the other major arsenic forms upon exposure of the pulverized coals to air.

Comparison of arsenic content in pelletized poultry house waste and biosolids fertilizer.

PubMed

Nachman, Keeve E; Mihalic, Jana N; Burke, Thomas A; Geyh, Alison S

2008-03-01

Managers of human biosolids have been incorporating the practice of waste pelletization for use as fertilizer since the mid 1920s, and waste pelletization has recently been embraced by some poultry producers as a way to move nutrients away from saturated agricultural land. However, the presence of arsenic in pelletized poultry house waste (PPHW) resulting from the use of organoarsenical antimicrobial drugs in poultry production raises concerns regarding additional incremental population exposures. Arsenic concentrations were determined in PPHW and pelletized biosolids fertilizer (PBF) samples. Pellets were processed using strong acid microwave digestion and analyzed by graphite furnace atomic absorption spectroscopy. The mean arsenic concentration in PPHW (20.1 ppm) fell within the lower part of the range of previously report arsenic concentrations in unpelletized poultry house waste. Arsenic concentrations in PBF, the source of which is less clear than for PPHW, were approximately a factor of 5 times lower than those in PPHW, with a mean concentration of 4.1 ppm. The pelletization and sale of these biological waste fertilizers present new pathways of exposure to arsenic in consumer populations who would otherwise not come into contact with these wastes. Arsenic exposures in humans resulting from use of these fertilizer pellets should be quantified to avoid potential unintended negative consequences of managing wastes through pelletization.

Factors Affecting Arsenic Methylation in Arsenic-Exposed Humans: A Systematic Review and Meta-Analysis

PubMed Central

Shen, Hui; Niu, Qiang; Xu, Mengchuan; Rui, Dongsheng; Xu, Shangzhi; Feng, Gangling; Ding, Yusong; Li, Shugang; Jing, Mingxia

2016-01-01

Chronic arsenic exposure is a critical public health issue in many countries. The metabolism of arsenic in vivo is complicated because it can be influenced by many factors. In the present meta-analysis, two researchers independently searched electronic databases, including the Cochrane Library, PubMed, Springer, Embase, and China National Knowledge Infrastructure, to analyze factors influencing arsenic methylation. The concentrations of the following arsenic metabolites increase (p< 0.000001) following arsenic exposure: inorganic arsenic (iAs), monomethyl arsenic (MMA), dimethyl arsenic (DMA), and total arsenic. Additionally, the percentages of iAs (standard mean difference (SMD): 1.00; 95% confidence interval (CI): 0.60–1.40; p< 0.00001) and MMA (SMD: 0.49; 95% CI: 0.21–0.77; p = 0.0006) also increase, while the percentage of DMA (SMD: −0.57; 95% CI: −0.80–−0.31; p< 0.0001), primary methylation index (SMD: −0.57; 95% CI: −0.94–−0.20; p = 0.002), and secondary methylation index (SMD: −0.27; 95% CI: −0.46–−0.90; p = 0.004) decrease. Smoking, drinking, and older age can reduce arsenic methylation, and arsenic methylation is more efficient in women than in men. The results of this analysis may provide information regarding the role of arsenic oxidative methylation in the arsenic poisoning process. PMID:26861378

Decreased DNA repair gene expression among individuals exposed to arsenic in United States drinking water.

PubMed

Andrew, Angeline S; Karagas, Margaret R; Hamilton, Joshua W

2003-04-10

Arsenic is well established as a human carcinogen, but its precise mechanism of action remains unknown. Arsenic does not directly damage DNA, but may act as a carcinogen through inhibition of DNA repair mechanisms, leading indirectly to increased mutations from other DNA damaging agents. The molecular mechanism underlying arsenic inhibition of nucleotide excision repair after UV irradiation (Hartwig et al., Carcinogenesis 1997;18:399-405) is unknown, but could be due to decreased expression of critical genes involved in nucleotide excision repair of damaged DNA. This hypothesis was tested by analyzing expression of repair genes and arsenic exposure in a subset of 16 individuals enrolled in a population based case-control study investigating arsenic exposure and cancer risk in New Hampshire. Toenail arsenic levels were inversely correlated with expression of critical members of the nucleotide excision repair complex, ERCC1 (r(2) = 0.82, p < 0.0001), XPF (r(2) = 0.56, p < 0.002), and XPB (r(2) = 0.75, p < 0.0001). The internal dose marker, toenail arsenic level, was more strongly associated with changes in expression of these genes than drinking water arsenic concentration. Our findings, based on human exposure to arsenic in a US population, show an association between biomarkers of arsenic exposure and expression of DNA repair genes. Although our findings need verification in a larger study group, they are consistent with the hypothesis that inhibition of DNA repair capacity is a potential mechanism for the co-carcinogenic activity of arsenic. Copyright 2003 Wiley-Liss, Inc.

Role of complex organic arsenicals in food in aggregate exposure to arsenic.

PubMed

Thomas, David J; Bradham, Karen

2016-11-01

For much of the world's population, food is the major source of exposure to arsenic. Exposure to this non-essential metalloid at relatively low levels may be linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is important in assessing risk and developing strategies that protect public health. Although most emphasis has been placed on inorganic arsenic as human carcinogen and toxicant, an array of arsenic-containing species are found in plants and animals used as foods. Here, we 2evaluate the contribution of complex organic arsenicals (arsenosugars, arsenolipids, and trimethylarsonium compounds) that are found in foods and consider their origins, metabolism, and potential toxicity. Commonalities in the metabolism of arsenosugars and arsenolipids lead to the production of di-methylated arsenicals which are known to exert many toxic effects. Evaluating foods as sources of exposure to these complex organic arsenicals and understanding the formation of reactive metabolites may be critical in assessing their contribution to aggregate exposure to arsenic. Copyright © 2016. Published by Elsevier B.V.

Arsenic levels among pregnant women and newborns in Canada: Results from the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort.

PubMed

Ettinger, Adrienne S; Arbuckle, Tye E; Fisher, Mandy; Liang, Chun Lei; Davis, Karelyn; Cirtiu, Ciprian-Mihai; Bélanger, Patrick; LeBlanc, Alain; Fraser, William D

2017-02-01

Arsenic is a common environmental contaminant from both naturally-occurring and anthropomorphic sources and human exposure can be detected in various tissues. Its toxicity depends on many factors including the chemical form, valence state, bioavailability, metabolism and detoxification within the human body. Of paramount concern, particularly with respect to health effects in children, is the timing of exposure as the prenatal and early life periods are more susceptible to toxic effects. The Maternal-Infant Research on Environmental Chemicals (MIREC) cohort was established to obtain national-level biomonitoring data for approximately 2,000 pregnant women and their infants between 2008 and 2011 from 10 Canadian cities. We measured total arsenic (As) in 1st and 3rd trimester maternal blood, umbilical cord blood, and infant meconium and speciated arsenic in 1st trimester maternal urine. Most pregnant women had detectable levels of total arsenic in blood (92.5% and 87.3%, respectively, for 1st and 3rd trimester); median difference between 1st and 3rd trimester was 0.1124µg/L (p<0.0001), but paired samples were moderately correlated (Spearman r=0.41, p<0.0001). Most samples were below the LOD for umbilical cord blood (50.9%) and meconium (93.9%). In 1st trimester urine samples, a high percentage (>50%) of arsenic species (arsenous acid (As-III), arsenic acid (As-V), monomethylarsonic acid (MMA), and arsenobetaine (AsB)) were also below the limit of detection, except dimethylarsinic acid (DMA). DMA (>85% detected) ranged from arsenic in blood and specific gravity-adjusted DMA in urine (Spearman r=0.33, p<0.0001). Among this population of pregnant woman and newborns, levels of arsenic measured in blood and urine were lower than national population figures for Canadian women of reproductive age (20-39 years). In general, higher arsenic levels were observed in women

METHYLATION INACTIVATES PENTAVALENT ARSENIC SPECIES BUT ACTIVATES TRIVALENT ARSENIC SPECIES TO POTENT GENOTOXICANTS

EPA Science Inventory

Methylation Inactivates Pentavalent Arsenic Species but Activates Trivalent Arsenic Species to Potent Genotoxicants

The sensitivity ofhumans to arsenic-induced cancer is thought to be related in part to the limited ability of humans to detoxify arsenic. Recently, methyl- ...

Arsenic toxicity and accumulation in radish as affected by arsenic chemical speciation.

PubMed

Carbonell-Barrachina, A A; Burló, F; López, E; Martínez-Sánchez, F

1999-07-01

Arsenic (As) uptake by Rhapanus sativus L. (radish), cv. Nueva Orleans, growing in soil-less culture conditions was studied in relation to the chemical form and concentration of As. A 4 x 3 factorial experiment was conducted with treatments consisting of four As chemical forms [As(III), As(V), MMAA, DMAA] and three As concentrations (1.0, 2.0, and 5.0 mg As L-1). None of the As treatments were clearly phytotoxic to this radish cultivar. Arsenic phytoavailability was primarily determined by the As chemical form present in the nutrient solution and followed the trend DMAA < or = As(V) < or = As(III) < MMAA. Root and shoot As concentrations significantly increased with increasing As application rates. Monomethyl arsonic acid treatments caused the highest As accumulation in both roots and shoots, and this organic arsenical showed a higher uptake rate than the other As compounds. Inner root As concentrations were, in general, within the normal range for As contents in food crops but root skin As levels were close or above the maximum threshold set for As content in edible fruit, crops and vegetables. The statement that toxicity limits plant As uptake to safe levels was not confirmed in our study. If radish plants are exposed to a large pulse of As, as growth on contaminated nutrient solutions, they may accumulate residues which are unacceptable for animal and human consumption without exhibiting symptoms of phytotoxicity.

The ecology of arsenic

USGS Publications Warehouse

Oremland, Ronald S.; Stolz, John F.

2003-01-01

Arsenic is a metalloid whose name conjures up images of murder. Nonetheless, certain prokaryotes use arsenic oxyanions for energy generation, either by oxidizing arsenite or by respiring arsenate. These microbes are phylogenetically diverse and occur in a wide range of habitats. Arsenic cycling may take place in the absence of oxygen and can contribute to organic matter oxidation. In aquifers, these microbial reactions may mobilize arsenic from the solid to the aqueous phase, resulting in contaminated drinking water. Here we review what is known about arsenic-metabolizing bacteria and their potential impact on speciation and mobilization of arsenic in nature.