Inorganic Arsenic Concentrations Research Articles

Associations of total urinary arsenic with total cholesterol and high-density lipoprotein among 12-17-year-old participants from the 2009-2016 NHANES cycles: A cross-sectional study.

Hypertension and diabetes are highly prevalent among US adults. Arsenic exposure is associated with these cardiometabolic morbidities but the relationship between arsenic exposure and cholesterol markers of cardiometabolic disease has not been elucidated, especially at younger ages, when many chronic diseases may initiate. This study examined the association of total urinary arsenic with total cholesterol (TC) and high-density lipoprotein cholesterol (HDL) and explored effect modification by weight status. The study sample consisted of 12-17-year-old participants with complete data from the 2009-2016 National Health and Nutrition Examination Survey cycles. The cross-sectional associations of creatinine-adjusted total urinary arsenic with TC and HDL were assessed using multivariable linear regression models with survey weights. Three models were built, adjusting for varying combinations of age, gender, race/ethnicity, weight status, survey cycle, family income to poverty ratio, reference person education level, arsenobetaine, and dimethylarsinic acid (DMA). Model adjustments for arsenobetaine approximated inorganic arsenic exposure, and further adjustment for DMA approximated unmethylated inorganic arsenic exposure. We also explored weight status (underweight/healthy, overweight, and obese) as a potential effect modifier of these relationships using stratified analyses and interaction tests. The final analytical sample consisted of 1,177 12-17-year-old participants. After adjusting for covariates and arsenobetaine, creatinine-adjusted arsenic was positively associated with HDL levels (β=0.063; 95% CI: 0.007, 0.119). Upon further adjustment for DMA, creatinine-adjusted arsenic was positively associated with HDL levels (β=0.079; 95% CI: 0.015, 0.143) and TC levels (β=0.258; 95% CI: 0.002, 0.515). No effect modification by weight status was observed. We found a positive association of approximated unmethylated inorganic arsenic exposure with TC, and contrary to our expectation, with HDL. There was no effect modification by weight status. Our findings should be confirmed by conducting longitudinal studies among adolescents exposed to low-level arsenic and focusing specifically on urinary inorganic arsenic concentrations.

Arsenic Activates the ER Stress-Associated Unfolded Protein Response via the Activating Transcription Factor 6 in Human Bronchial Epithelial Cells.

Arsenic is a well-known human carcinogen associated with a number of cancers, including lung cancers. We have previously shown that long-term exposure to an environmentally relevant concentration of inorganic arsenic (As3+) leads to the malignant transformation of the BEAS2B cells, and some of the transformed cells show cancer stem-like features (CSCs) with a significant upregulation of glycolysis and downregulation of mitochondrial oxidative phosphorylation. In the present report, we investigate the short-term effect of As3+ on the endoplasmic reticulum (ER) stress response—the “unfolded protein response (UPR)” and metabolism in human bronchial epithelial cell line BEAS-2B cells. Treatment of the cells with inorganic As3+ upregulated both glycolysis and mitochondrial respiration. Analysis of ER UPR signaling pathway using a real-time human UPR array revealed that As3+ induced a significant up-regulation of some UPR genes, including ATF6, CEBPB, MAPK10, Hsp70, and UBE2G2. Additional tests confirmed that the induction of ATF6, ATF6B and UBE2G2 mRNAs and/or proteins by As3+ is dose dependent. Chromosome immunoprecipitation and global sequencing indicated a critical role of Nrf2 in mediating As3+-induced expression of these UPR genes. In summary, our data suggest that As3+ is able to regulate the ER stress response, possibly through activating the ATF6 signaling.

Bioaccumulation of arsenic and immunotoxic effect in white shrimp (Penaeus vannamei) exposed to trivalent arsenic

Trivalent arsenic (As (III)) contamination in the marine environment can produce adverse effects in crustaceans. The present study investigated the chronic toxicity of As (III) in white shrimp (Penaeus vannamei) by analyzing the tissue bioaccumulation and non-specific immune responses. Shrimps were exposed to 0 (control), 50, 500, and 2500 μg/L of As (III) for 21 days. The results showed that the hepatopancreas was the main tissue of arsenic accumulation in white shrimp. The cumulative concentration of total arsenic and inorganic arsenic but not arsenobetaine was positively correlated with the exposure concentration. In vitro As (III) treatment (0–2500 μg/L) with haemocytes isolated from healthy shrimp did not cause the cytotoxicity, but this arsenic treatments inhibited the phagocytic rate and O2− production. Moreover, the decrease of total haemocyte count and the inhibition of phagocytic rate, phagocytic index, O2− production and phenoloxidase activity were observed in white shrimp under the exposure of As (III) over a period of 21 days. This study revealed that chronic As (III) stress could disturb arsenic metabolism and immune responses in P. vannamei.

Arsenic in Portuguese Rice: Is There Any Risk?

Arsenic is a metalloid with natural and anthropogenic sources and its inorganic form is toxic to humans. Rice is highly consumed worldwide and is prone to arsenic contamination; therefore, this study evaluated the inorganic arsenic content of 70 Portuguese rice samples. These were analysed through inductively coupled plasma mass spectrometry (ICP-MS) with a detection limit of 3.3 µg kg−1. The average contamination was of 29.3 µg kg−1, with brown and short rice presenting higher values than white and long rice. The highest concentration, 100 µg kg−1, equalled the maximum residue limit (MRL) for rice destined for infants’ consumption. The estimated daily intake (EDI) surpassed the benchmark dose (lower confidence limit 10%) (BMDL10) of 0.3 µg kg−1 of bw/day considering children in the 95th percentile of rice consumption and the worst-case scenario concentration. However, other sources also contribute to the EDI and some population groups can exceed the BMDL10.

Arsenic exposure and biomarkers for oxidative stress and telomere length in indigenous populations in Bolivia

BackgroundWomen living in the Bolivian Andes are environmentally exposed to arsenic, yet there is scarce information about arsenic-related effects in this region. Several biomarkers for telomere length and oxidative stress (mitochondrial DNA copy number, mtDNAcn; 8-Oxo-2′-deoxyguanosine, 8-oxo-dG; and 4-hydroxy nonenal mercapturic acid, 4-HNE-MA) have been previously linked to arsenic, and some of which are prospective biomarkers for cancer risk. Objective and hypothesisTo evaluate associations between arsenic exposure and telomere length, mtDNAcn, 8-oxo-dG, and 4-HNE-MA in Bolivians. Arsenic exposure was hypothesized to be positively associated with all four toxicity biomarkers, particularly in individuals with a less efficient arsenic metabolism. MethodsThe study encompassed 193 indigenous women. Arsenic exposure was assessed in urine as the sum of inorganic arsenic metabolite concentrations (U-As) measured by HPLC-HG-ICP-MS, and in whole blood as total arsenic (B-As) measured by ICP-MS. Efficiency of arsenic metabolism was evaluated by a polymorphism (rs3740393) in the main arsenic methylating gene AS3MT measured by TaqMan allelic discrimination, and by the relative fractions of urinary inorganic arsenic metabolites. Telomere length and mtDNAcn were determined in peripheral blood leukocytes by quantitative PCR, and urinary 8-oxo-dG and 4-HNE-MA by LC-MS/MS. ResultsU-As and B-As were associated with longer telomeres and higher mtDNAcn, particularly in women with a less efficient arsenic metabolism. Urinary 8-oxo-dG and 4-HNE-MA were positively associated with U-As, but only 4-HNE-MA was associated with B-As. Arsenic metabolism efficiency did not have a clear effect on the concentrations of either of these biomarkers. ConclusionBolivian women showed indications of arsenic toxicity, measured by four different biomarkers. Telomere length, mtDNAcn, and 4-HNE-MA were positively associated with both U-As and B-As. The association of arsenic exposure with telomere length and mtDNAcn was only present in Bolivian women with a less efficient metabolism. These findings call for additional efforts to evaluate and reduce arsenic exposure in Bolivia.

Validation of an analytical method for the determination of inorganic, organic, and total arsenic in fish sauce based on hydride generation atomic absorption spectrometry

An atomic absorption spectrometric (AAS) method was performed to determine the total, inorganic, and organic arsenic in fish sauce. The total organic arsenic was calculated from the total and inorganic arsenic values quantified using the hydride generation AAS (HG-AAS). Under optimal experimental conditions at the absorbance wavelength of 193.7 nm, the concentration of inorganic arsenic in fish sauce ranged from 0.05 to 1.2 mg/L, with a limit of detection (LOD) of 0.015 mg/L. The detectable total arsenic concentrations varied widely, ranging from 0.03 to 2.5 mg/L with the LOD of as low as 0.01 mg/L. The practical applicability of the method was demonstrated with the recovery in the range from 97 to 102% for inorganic arsenic, and 97 to 101% for organic arsenic. The method was applied to the analysis of commercial products from Nha Trang, Phan Thiet, and Phu Quoc City, Vietnam. The total organic arsenic in fish sauce samples determined by HG-AAS was compared with the results of liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP/MS). The f-test and t-test showed null hypothesis for acceptable variance and mean at a confidence level of 95%. The results showed that the HG-AAS method had high efficiency, accuracy, and sensitivity in quantifying inorganic and total organic arsenic in fish sauce using simple instrumentation.

Determination of Arsenic Content in Water Using a Silver Coordination Polymer.

In this report, we describe a practical method for the colorimetric determination of dissolved inorganic arsenic content in water samples, using a silver coordination polymer as the sensing material. We demonstrate that a crystalline polymer framework can be used to stabilize silver(I) ions, greatly reducing both photosensitivity and water solubility, while still affording sufficient reactivity to detect arsenic in water samples at low parts-per-billion (ppb) levels. Test strips fabricated with the silver-based polymer are shown to be effective for field tests of groundwater under real-world operating conditions and display performance that is competitive with commercially available mercury-based test strips. Spectroscopic methods are also used to probe the reaction products formed, in order to better understand the sensing mechanism. Thus, our work provides the foundation for an improved field test that could be deployed to help manage groundwater usage in regions where arsenic contamination is problematic but sophisticated lab testing is not readily available.

Determination of Inorganic Arsenic for Pet Food by LC-ICP-MS

We have developed a quantitative determination method of the concentration of inorganic arsenic in pet foods using a liquid chromatograph-inductively coupled plasma-mass spectrometer (LC-ICP-MS). After adding 2 w/v% TMAH solution to a sample, inorganic arsenic was extracted by heating and the extract was collected by water. The pH of the solution was adjusted, and injected into a LC-ICP-MS to determine the concentration of inorganic arsenic. LC separation was carried out on an ODS column with 10 mmol/L sodium 1-butanesulfonate, 4 mmol/L malonic acid, 4 mmol/L TMAH and 0.05% methanol solution as a mobile phase. A collaborative study was conducted by nine laboratories using dry and wet-type pet foods, formed jerky, dried jerky and biscuit. Dry-type pet food and dried jerky was added with 2 mg/kg of As (III). Wet-type pet food was added with 0.5 mg/kg of As (III). Formed jerky was added with 1 mg/kg of As (III). Biscuit was added with 0.2 mg/kg of As (III). The mean recoveries, repeatabilities and reproducibilities in the form of relative standard deviation (RSDr and RSDR), and HorRat, were 95.4% to 98.3%, less than 2.9%, less than 9.1%, and 0.22 to 0.51, respectively.

Provision of folic acid for reducing arsenic toxicity in arsenic-exposed children and adults.

Provision of folic acid for reducing arsenic toxicity in arsenic-exposed children and adults.

Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Complex Compounds in Serum and Its Application in Accurate Detection of Early Arsenic Exposure.

With the acceleration of industrialization, environmental arsenic pollution is threatening human health. However, by the time clinical symptoms appear, arsenic toxicity has usually caused irreversible damage to the body, so it is important to establish a rapid and accurate screening method for early arsenic exposure. In this work, 32 female C57BL/6 mice were exposed to different concentrations of inorganic arsenic in drinking water for a week. By analyzing the changes in serum, more than 20 compounds were detected to increase or decrease with the increase of arsenic intake. The abnormal increase in inosine, xanthine, xanthosine, and hypoxanthine and the abnormal purine pathway were found at the same time. Dimethylarsenic acid, an important inorganic arsenic metabolite in the body, was also found in serum. Combined with statistical analysis, early arsenic exposure can be easily and quickly detected, and the potential health risks of short-term exposure can be revealed simultaneously.

VALIDATION OF AN ANALYTICAL METHOD FOR THE DETERMINATION OF INORGANIC AND ORGANIC ARSENIC IN FISH SAUCE BY HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROSCOPY

The validation of an analytical method was carried out for the determination of arsenic components in fish sauce by HG-AAS. The total arsenic content (tAs) was analyzed after digesting the sample by dry and wet combined digestion method in a Teflon flask at 450 °C and then reducing As (V) to As (III) with a mixture of reducing agents KI/ascorbic acid. For inorganic arsenic content (iAs), the sample was hydrolyzed with HCl solution for 14 hours, converted As (V) to As (III), then reacted with hydrazine 1.5%. Extracted in CHCl3 and re-extracted in HNO3. The organic arsenic content (oAs) was calculated by the difference tAs and iAs. Determined the linear concentration range 2 - 30 μg/L and the standard curve was y = 0.0128x + 0.0007 with R² = 0.9996 at the concentration range 2 - 20 μg/L. LODs, LOQs for total and inorganic arsenic contents were found and all they were 0.015 mg/L and 0.05 mg/L, respectively. For total arsenic, the recovery efficiencies on the organic arsenic standard and inorganic arsenic standard all ranged from 81 to 109%;...

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Arsenic speciation in fish from Baltic Sea close to chemical munitions dumpsites

Chemical weapons that were dumped in seas and oceans after World War II, including the Baltic Sea, are sources of pollution of marine areas. Sunken containers can corrode, unseal, and numerous compounds pass into the environment, including toxic forms of arsenic, which are then taken up by marine animals. This study aims to quantify concentration of total arsenic, inorganic arsenic (III + V), and organic compounds arsenobetaine, monomethylarsonic acid, dimethylarsinic acid in the muscle tissues of cod, herring, sprat, and flounder and the associated risk to consumer health. Sprat muscle (0.636 mg kg−1) had the highest content of total arsenic, significantly less was noted in the muscles of herring (0.460 mg kg−1) and flounder (0.588 mg kg−1), and the least was in cod (0.390 mg kg−1). Toxic inorganic arsenic compounds were present in the fish tested at levels below 0.02 mgkg−1 and constituted from 3.45 to 5.75% of total arsenic. Arsenobetaine dominated among organic forms, and concentrations of it, like total arsenic, varied depending on the fish species. Consumer health risk was determined with the estimated daily intake, the target hazard quotient, and the carcinogenic risk. Estimated daily intake values for inorganic arsenic in herring, cod, sprat, and flounder were below the reference dose at 0.51 × 10−5 mg kg−1 b. w. day. The target hazard quotient factor of 0.0017 indicated there was no threat. Carcinogenic risk values were within the permissible range of 10−6 to 10−4. Current data indicate that inorganic arsenic compounds pose no risk to the health of consumers of Baltic fishes.

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Contribution of diet and other factors for urinary concentrations of total arsenic and arsenic species: data for US children, adolescents, and adults.

A comprehensive analysis of the associations between the consumptions of 17 food products with urinary concentrations of arsenobetaine, total arsenic, arsenous acid, dimethylarsinic acid (UDMA), monomethylarsonic acid (UMMA), and total inorganic arsenic for US children aged 3-5 years (N = 439), children aged 6-11 years (N = 2139), adolescents aged 12-19 years (N = 2434), and adults aged >= 20 years (N = 10902) was conducted. Data from National Health and Nutrition Examination Survey for 2005-2016 were used for this study. Concentrations of arsenobetaine were as much as > 15 times higher among consumers of fish/shellfish than non-consumers for children aged 6-11 years, > 12 times higher for children aged 3-5 years, > 13 times higher for adolescents, and > 7 times higher for adults. Consumption of rice as opposed to non-consumption of rice was associated with as much as 36.5% higher concentrations of total arsenic, 12.7% higher concentrations of arsenous acid, 43.9% higher concentrations of UDMA, 18.2% higher concentrations of UMMA, and 14.1% higher concentrations of total inorganic arsenic. Thus, consumption of fish/shell fish and rice was associated with higher concentrations of organic/inorganic arsenic. In addition, consumption of alcohol was also found to be associated with higher concentrations of organic/inorganic arsenic. However, consumption of milk and milk products, vegetables, organ and other meats, and nutritional drinks was found to be associated with lower concentrations of organic/inorganic arsenic. Thus, while consumption of several foods is associated with higher concentrations of arsenic, there are also foods whose consumption is associated with decreased concentrations of arsenic. Further studies are needed to identify foods that may lead to decreased concentrations of arsenic and as such arsenic toxicity.

Method validation for As speciation in rice using LC-ICP-MS and the inorganic arsenic limit for Brazilian rice

A methodology for As speciation in rice using liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) was optimised and validated. Chromatographic separation and elution of As(III), DMA(V) (dimethylarsenic acid), MMA(V) (monomethylarsenic acid) and As(V) were achieved in less than 8 min using 10 mmol L−1 (NH4)2HPO4 as the mobile phase, at pH 6 and a flow rate of 1.4 mL min−1. The limits of detection for As(III), DMA(V), MMA(V) and As(V) in rice were 1.87, 2.89, 0.54 and 3.00 ng g-1, respectively. The method’s accuracy was assessed through analyte recovery tests and analysis of certified reference materials, which included white and brown rice flours. The validated method was applied for As speciation in 640 rice samples, comprising polished (white) rice, parboiled rice and brown rice collected from different mesoregions in the Rio Grande do Sul State in Brazil. By comparing the total concentration of As (tAs) found in the acid digested samples with the As species sum, the average extraction efficiencies were 98 ± 13%, 93 ± 12% and 86 ± 6%, for white, parboiled, and brown rice, respectively. The average concentrations of inorganic arsenic (iAs, that is As(III) + As(V)), DMA and tAs in brown and parboiled rice were not different but differed from those in white rice; the average concentrations of tAs, iAs and DMA in brown and parboiled rice were higher than those found in white rice were. The iAs concentration in all rice samples was lower than 200 ng g−1, which could be recommended as the maximum iAs concentration for Brazilian rice.

Grain Inorganic Arsenic Content in Rice Managed Through Targeted Introgressions and Irrigation Management.

Arsenic (As) accumulation in rice grain is a significant public health concern. Inorganic As (iAs) is of particular concern because it has increased toxicity as compared to organic As. Irrigation management practices, such as alternate wetting and drying (AWD), as well as genotypic differences between cultivars, have been shown to influence As accumulation in rice grain. A 2 year field study using a Lemont × TeQing backcross introgression line (TIL) mapping population examined the impact of genotype and AWD severity on iAs grain concentrations. The “Safe”-AWD [35–40% soil volumetric water content (VWC)] treatment did not reduce grain iAs levels, whereas the more severe AWD30 (25–30% VWC) consistently reduced iAs concentrations across all genotypes. The TILs displayed a range of iAs concentrations by genotype, from less than 10 to up to 46 μg kg–1 under AWD30 and from 28 to 104 μg kg–1 under Safe-AWD. TIL grain iAs concentrations for flood treatments across both years ranged from 26 to 127 μg kg–1. Additionally, seven quantitative trait loci (QTLs) were identified in the mapping population associated with grain iAs. A subset of eight TILs and their parents were grown to confirm field-identified grain iAs QTLs in a controlled greenhouse environment. Greenhouse results confirmed the genotypic grain iAs patterns observed in the field; however, iAs concentrations were higher under greenhouse conditions as compared to the field. In the greenhouse, the number of days under AWD was negatively correlated with grain iAs concentrations. Thus, longer drying periods to meet the same soil VWC resulted in lower grain iAs levels. Both the number and combinations of iAs-affecting QTLs significantly impacted grain iAs concentrations. Therefore, identifying more grain iAs-affecting QTLs could be important to inform future breeding efforts for low iAs rice varieties. Our study suggests that coupling AWD practices targeting a soil VWC of less than or equal to 30% coupled with the use of cultivars developed to possess multiple QTLs that negatively regulate grain iAs concentrations will be helpful in mitigating exposure of iAs from rice consumption.

Effects of water management on inorganic arsenic concentration in rice grains in V-furrow direct seeding cultivation

Effects of water management on inorganic arsenic concentration in rice grains in V-furrow direct seeding cultivation

Effects of heavy metals on the expression of digestive enzyme-coding genes in the brackish water flea Diaphanosoma celebensis

Energy metabolism is an essential physiological event for all life forms, and, in heterotrophic organisms, it significantly depends on food intake. Digestive enzymes play an important role in acquiring the nutrients required for metabolic pathways. Thus, the aim of this study was to investigate the transcriptional modulation of digestive enzyme-coding genes in response to heavy metals in the brackish water flea Diaphanosoma celebensis. Sublethal concentrations of inorganic arsenic (As), cadmium (Cd), and lead (Pb) on the brackish water flea D. celebensis were calculated from the 48 h acute toxicity test result. The relative mRNA expression levels of six digestive enzyme-coding genes (AMY and AMY-like for carbohydrates; TRYP and CHY for proteins; LIP and PLRP for lipids) after 48 h of exposure to heavy metals were evaluated by real-time reverse transcription-polymerase chain reaction. A significant increase in the mRNA expression of AMY, AMY-like, TRYP, and PLRP was observed in all concentration of As (1.17–3.94 fold-change, p Pb > As. The increase in digestive enzyme-coding genes in response to As and a lower concentration of Pb may be closely associated with protective effects to compensate for changing food availability. Cd and the higher concentration of Pb could disrupt energy metabolism by downregulating the digestive enzyme-coding genes.