Roxarsone, inorganic arsenic, and other arsenic species in chicken: a U.S.-based market basket sample.

PubMed

Nachman, Keeve E; Baron, Patrick A; Raber, Georg; Francesconi, Kevin A; Navas-Acien, Ana; Love, David C

2013-07-01

Inorganic arsenic (iAs) causes cancer and possibly other adverse health outcomes. Arsenic-based drugs are permitted in poultry production; however, the contribution of chicken consumption to iAs intake is unknown. We sought to characterize the arsenic species profile in chicken meat and estimate bladder and lung cancer risk associated with consuming chicken produced with arsenic-based drugs. Conventional, antibiotic-free, and organic chicken samples were collected from grocery stores in 10 U.S. metropolitan areas from December 2010 through June 2011. We tested 116 raw and 142 cooked chicken samples for total arsenic, and we determined arsenic species in 65 raw and 78 cooked samples that contained total arsenic at ≥ 10 µg/kg dry weight. The geometric mean (GM) of total arsenic in cooked chicken meat samples was 3.0 µg/kg (95% CI: 2.5, 3.6). Among the 78 cooked samples that were speciated, iAs concentrations were higher in conventional samples (GM = 1.8 µg/kg; 95% CI: 1.4, 2.3) than in antibiotic-free (GM = 0.7 µg/kg; 95% CI: 0.5, 1.0) or organic (GM = 0.6 µg/kg; 95% CI: 0.5, 0.8) samples. Roxarsone was detected in 20 of 40 conventional samples, 1 of 13 antibiotic-free samples, and none of the 25 organic samples. iAs concentrations in roxarsone-positive samples (GM = 2.3 µg/kg; 95% CI: 1.7, 3.1) were significantly higher than those in roxarsone-negative samples (GM = 0.8 µg/kg; 95% CI: 0.7, 1.0). Cooking increased iAs and decreased roxarsone concentrations. We estimated that consumers of conventional chicken would ingest an additional 0.11 µg/day iAs (in an 82-g serving) compared with consumers of organic chicken. Assuming lifetime exposure and a proposed cancer slope factor of 25.7 per milligram per kilogram of body weight per day, this increase in arsenic exposure could result in 3.7 additional lifetime bladder and lung cancer cases per 100,000 exposed persons. Conventional chicken meat had higher iAs concentrations than did conventional antibiotic

Use of arsenic-73 in research supports USEPA's regulatory decisions on inorganic arsenic in drinking water*

EPA Science Inventory

Inorganic arsenic is a natural contaminant of drinking water in the United States and throughout the world. Long term exposure to inorganic arsenic in drinking water at elevated levels (>100 ug/L) is associated with development of cancer in several organs, cardiovascular disease,...

Roxarsone, Inorganic Arsenic, and Other Arsenic Species in Chicken: A U.S.-Based Market Basket Sample

PubMed Central

Baron, Patrick A.; Raber, Georg; Francesconi, Kevin A.; Navas-Acien, Ana; Love, David C.

2013-01-01

Background: Inorganic arsenic (iAs) causes cancer and possibly other adverse health outcomes. Arsenic-based drugs are permitted in poultry production; however, the contribution of chicken consumption to iAs intake is unknown. Objectives: We sought to characterize the arsenic species profile in chicken meat and estimate bladder and lung cancer risk associated with consuming chicken produced with arsenic-based drugs. Methods: Conventional, antibiotic-free, and organic chicken samples were collected from grocery stores in 10 U.S. metropolitan areas from December 2010 through June 2011. We tested 116 raw and 142 cooked chicken samples for total arsenic, and we determined arsenic species in 65 raw and 78 cooked samples that contained total arsenic at ≥ 10 µg/kg dry weight. Results: The geometric mean (GM) of total arsenic in cooked chicken meat samples was 3.0 µg/kg (95% CI: 2.5, 3.6). Among the 78 cooked samples that were speciated, iAs concentrations were higher in conventional samples (GM = 1.8 µg/kg; 95% CI: 1.4, 2.3) than in antibiotic-free (GM = 0.7 µg/kg; 95% CI: 0.5, 1.0) or organic (GM = 0.6 µg/kg; 95% CI: 0.5, 0.8) samples. Roxarsone was detected in 20 of 40 conventional samples, 1 of 13 antibiotic-free samples, and none of the 25 organic samples. iAs concentrations in roxarsone-positive samples (GM = 2.3 µg/kg; 95% CI: 1.7, 3.1) were significantly higher than those in roxarsone-negative samples (GM = 0.8 µg/kg; 95% CI: 0.7, 1.0). Cooking increased iAs and decreased roxarsone concentrations. We estimated that consumers of conventional chicken would ingest an additional 0.11 µg/day iAs (in an 82-g serving) compared with consumers of organic chicken. Assuming lifetime exposure and a proposed cancer slope factor of 25.7 per milligram per kilogram of body weight per day, this increase in arsenic exposure could result in 3.7 additional lifetime bladder and lung cancer cases per 100,000 exposed persons. Conclusions: Conventional chicken meat had higher i

Association between lifetime exposure to inorganic arsenic in drinking water and coronary heart disease in Colorado residents.

PubMed

James, Katherine A; Byers, Tim; Hokanson, John E; Meliker, Jaymie R; Zerbe, Gary O; Marshall, Julie A

2015-02-01

Chronic diseases, including coronary heart disease (CHD), have been associated with ingestion of drinking water with high levels of inorganic arsenic (> 1,000 μg/L). However, associations have been inconclusive in populations with lower levels (< 100 μg/L) of inorganic arsenic exposure. We conducted a case-cohort study based on individual estimates of lifetime arsenic exposure to examine the relationship between chronic low-level arsenic exposure and risk of CHD. This study included 555 participants with 96 CHD events diagnosed between 1984 and 1998 for which individual lifetime arsenic exposure estimates were determined using data from structured interviews and secondary data sources to determine lifetime residence, which was linked to a geospatial model of arsenic concentrations in drinking water. These lifetime arsenic exposure estimates were correlated with historically collected urinary arsenic concentrations. A Cox proportional-hazards model with time-dependent CHD risk factors was used to assess the association between time-weighted average (TWA) lifetime exposure to low-level inorganic arsenic in drinking water and incident CHD. We estimated a positive association between low-level inorganic arsenic exposure and CHD risk [hazard ratio (HR): = 1.38, 95% CI: 1.09, 1.78] per 15 μg/L while adjusting for age, sex, first-degree family history of CHD, and serum low-density lipoprotein levels. The risk of CHD increased monotonically with increasing TWAs for inorganic arsenic exposure in water relative to < 20 μg/L (HR = 1.2, 95% CI: 0.6, 2.2 for 20-30 μg/L; HR = 2.2; 95% CI: 1.2, 4.0 for 30-45 μg/L; and HR = 3, 95% CI: 1.1, 9.1 for 45-88 μg/L). Lifetime exposure to low-level inorganic arsenic in drinking water was associated with increased risk for CHD in this population.

METHYLATED ASIII COMPOUNDS AS POTENTIAL PROXIMATE/ULTIMATE GENOTOXIC METABOLITES OF INORGANIC ARSENIC

EPA Science Inventory

METHYLATED Asm COMPOUNDS AS POTENTIAL PROXIMATE/ULTIMATE GENOTOXIC METABOLITES OF INORGANIC ARSENIC.

The methylation of inorganic arsenic has typically been viewed as a detoxification process. Genotoxicity tests have generally shown that arsenite has greater mutagenic p...

High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking.

PubMed

Rahman, M Azizur; Hasegawa, H

2011-10-15

Rice is the staple food for the people of arsenic endemic South (S) and South-East (SE) Asian countries. In this region, arsenic contaminated groundwater has been used not only for drinking and cooking purposes but also for rice cultivation during dry season. Irrigation of arsenic-contaminated groundwater for rice cultivation has resulted high deposition of arsenic in topsoil and uptake in rice grain posing a serious threat to the sustainable agriculture in this region. In addition, cooking rice with arsenic-contaminated water also increases arsenic burden in cooked rice. Inorganic arsenic is the main species of S and SE Asian rice (80 to 91% of the total arsenic), and the concentration of this toxic species is increased in cooked rice from inorganic arsenic-rich cooking water. The people of Bangladesh and West Bengal (India), the arsenic hot spots in the world, eat an average of 450g rice a day. Therefore, in addition to drinking water, dietary intake of arsenic from rice is supposed to be another potential source of exposure, and to be a new disaster for the population of S and SE Asian countries. Arsenic speciation in raw and cooked rice, its bioavailability and the possible health hazard of inorganic arsenic in rice for the population of S and SE Asia have been discussed in this review. Copyright © 2011 Elsevier B.V. All rights reserved.

Inorganic arsenic in rice bran and its products are an order of magnitude higher than in bulk grain.

PubMed

Sun, Guo-Xin; Williams, Paul N; Carey, Anne-Marie; Zhu, Yong-Guan; Deacon, Claire; Raab, Andrea; Feldmann, Joerg; Islam, Rafiqul M; Meharg, Andrew A

2008-10-01

Rice is more elevated in arsenic than all other grain crops tested to date, with whole grain (brown) rice having higher arsenic levels than polished (white). It is reported here that rice bran, both commercially purchased and specifically milled for this study, have levels of inorganic arsenic, a nonthreshold, class 1 carcinogen, reaching concentrations of approximately 1 mg/kg dry weight, around 10-20 fold higher than concentrations found in bulk grain. Although pure rice bran is used as a health food supplement, perhaps of more concern is rice bran solubles, which are marketed as a superfood and as a supplement to malnourished children in international aid programs. Five rice bran solubles products were tested, sourced from the United States and Japan, and were found to have 0.61-1.9 mg/kg inorganic arsenic. Manufactures recommend approximately 20 g servings of the rice bran solubles per day, which equates to a 0.012-0.038 mg intake of inorganic arsenic. There are no maximum concentration levels (MCLs) set for arsenic or its species in food stuffs. EU and U.S. water regulations, set at 0.01 mg/L total or inorganic arsenic, respectively, are based on the assumption that 1 L of water per day is consumed, i.e., 0.01 mg of arsenic/ day. At the manufacturers recommended rice bran solubles consumption rate, inorganic arsenic intake exceeds 0.01 mg/ day, remembering that rice bran solubles are targeted at malnourished children and that actual risk is based on mg kg(-1) day(-1) intake.

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

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

29 CFR 1926.1118 - Inorganic arsenic.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Toxic and Hazardous Substances § 1926.1118 Inorganic arsenic. Note: The requirements applicable to construction work under this section are identical...

IRIS Toxicological Review of Ingested Inorganic Arsenic (2005 ...

EPA Pesticide Factsheets

EPA's Office of Research and Development (ORD), Office of Pesticide Programs (OPP), and Office of Water (OW) requested the SAB to provide advice to the Agency on several issues about the mode of carcinogenic action of various arsenic species and the implications of these issues for EPA's assessment of the cancer hazard and risks of organic and inorganic arsenic. The panel will review an OPP Science Issue Paper (with an attachment prepared by ORD) and a revised hazard and dose response assessment/characterization for inclusion in the Integrated Risk Information System (IRIS) prepared by OW. Inorganic arsenic is used for hardening copper and lead alloys. It also is used in glass manufacturing as a decolorizing and refining agent, as a component of electrical devices, in the semiconductor industry, and as a catalyst in the production of ethylene oxide.

Geographical variation in total and inorganic arsenic content of polished (white) rice.

PubMed

Meharg, Andrew A; Williams, Paul N; Adomako, Eureka; Lawgali, Youssef Y; Deacon, Claire; Villada, Antia; Cambell, Robert C J; Sun, Guoxin; Zhu, Yong-Guan; Feldmann, Joerg; Raab, Andrea; Zhao, Fang-Jie; Islam, Rafiqul; Hossain, Shahid; Yanai, Junta

2009-03-01

An extensive data set of total arsenic analysis for 901 polished (white) grain samples, originating from 10 countries from 4 continents, was compiled. The samples represented the baseline (i.e., notspecifically collected from arsenic contaminated areas), and all were for market sale in major conurbations. Median total arsenic contents of rice varied 7-fold, with Egypt (0.04 mg/kg) and India (0.07 mg/kg) having the lowest arsenic content while the U.S. (0.25 mg/kg) and France (0.28 mg/kg) had the highest content. Global distribution of total arsenic in rice was modeled by weighting each country's arsenic distribution by that country's contribution to global production. A subset of 63 samples from Bangladesh, China, India, Italy, and the U.S. was analyzed for arsenic species. The relationship between inorganic arsenic contentversus total arsenic contentsignificantly differed among countries, with Bangladesh and India having the steepest slope in linear regression, and the U.S. having the shallowest slope. Using country-specific rice consumption data, daily intake of inorganic arsenic was estimated and the associated internal cancer risk was calculated using the U.S. Environmental Protection Agency (EPA) cancer slope. Median excess internal cancer risks posed by inorganic arsenic ranged 30-fold for the 5 countries examined, being 0.7 per 10,000 for Italians to 22 per 10,000 for Bangladeshis, when a 60 kg person was considered.

Total and inorganic arsenic in rice and rice bran purchased in Thailand.

PubMed

Ruangwises, Suthep; Saipan, Piyawat; Tengjaroenkul, Bundit; Ruangwises, Nongluck

2012-04-01

Concentrations of total and inorganic arsenic were determined in 180 samples of polished and brown rice of three rice types, namely white, jasmine, and sticky, and 44 samples of rice bran from these three rice types purchased in Thailand. Concentrations (expressed in nanograms per gram) of inorganic arsenic in polished white, jasmine, and sticky rice were 68.3 ± 17.6 (with a range of 45.0 to 106), 68.4 ± 15.6 (41.7 to 101), and 75.9 ± 24.8 (43.5 to 156), respectively, while those in the three brown rice samples were 124 ± 34.4 (74.5 to 193), 120 ± 31.6 (73.1 to 174), and 131 ± 35.6 (78.0 to 188), respectively. Inorganic arsenic concentrations (expressed in nanograms per gram) in rice bran produced from the three rice types were 633 ± 182 (375 to 919), 599 ± 112 (447 to 824), and 673 ± 195 (436 to 1,071), respectively. Rice bran contained concentrations of total and inorganic arsenic approximately seven and nine times higher, respectively, than those found in the corresponding polished rice. The levels of inorganic arsenic in the three rice types of both polished and brown rice were within the only published regulatory limit of 200 ng/g.

Nitarsone, Inorganic Arsenic, and Other Arsenic Species in Turkey Meat: Exposure and Risk Assessment Based on a 2014 U.S. Market Basket Sample

PubMed Central

Nachman, Keeve E.; Love, David C.; Baron, Patrick A.; Nigra, Anne E.; Murko, Manuela; Raber, Georg; Francesconi, Kevin A.; Navas-Acien, Ana

2016-01-01

Background: Use of nitarsone, an arsenic-based poultry drug, may result in dietary exposures to inorganic arsenic (iAs) and other arsenic species. Nitarsone was withdrawn from the U.S. market in 2015, but its use in other countries may continue. Objectives: We characterized the impact of nitarsone use on arsenic species in turkey meat and arsenic exposures among turkey consumers, and we estimated cancer risk increases from consuming turkey treated with nitarsone before its 2015 U.S. withdrawal. Methods: Turkey from three cities was analyzed for total arsenic, iAs, methylarsonate (MA), dimethylarsinate, and nitarsone, which were compared across label type and month of purchase. Turkey consumption was estimated from NHANES data to estimate daily arsenic exposures for adults and children 4–30 months of age and cancer risks among adult consumers. Results: Turkey meat from conventional producers not prohibiting nitarsone use showed increased mean levels of iAs (0.64 μg/kg) and MA (5.27 μg/kg) compared with antibiotic-free and organic meat (0.39 μg/kg and 1.54 μg/kg, respectively) and meat from conventional producers prohibiting nitarsone use (0.33 μg/kg and 0.28 μg/kg, respectively). Samples with measurable nitarsone had the highest mean iAs and MA (0.92 μg/kg and 10.96 μg/kg, respectively). Nitarsone was higher in October samples than in March samples, possibly resulting from increased summer use. Based on mean iAs concentrations in samples from conventional producers with no known policy versus policies prohibiting nitarsone, estimated lifetime daily consumption by an 80-kg adult, and a recently proposed cancer slope factor, we estimated that use of nitarsone by all turkey producers would result in 3.1 additional cases of bladder or lung cancer per 1,000,000 consumers. Conclusions: Nitarsone use can expose turkey consumers to iAs and MA. The results of our study support the U.S. Food and Drug Administration’s removal of nitarsone from the U.S. market and

Nitarsone, Inorganic Arsenic, and Other Arsenic Species in Turkey Meat: Exposure and Risk Assessment Based on a 2014 U.S. Market Basket Sample.

PubMed

Nachman, Keeve E; Love, David C; Baron, Patrick A; Nigra, Anne E; Murko, Manuela; Raber, Georg; Francesconi, Kevin A; Navas-Acien, Ana

2017-03-01

Use of nitarsone, an arsenic-based poultry drug, may result in dietary exposures to inorganic arsenic (iAs) and other arsenic species. Nitarsone was withdrawn from the U.S. market in 2015, but its use in other countries may continue. We characterized the impact of nitarsone use on arsenic species in turkey meat and arsenic exposures among turkey consumers, and we estimated cancer risk increases from consuming turkey treated with nitarsone before its 2015 U.S. withdrawal. Turkey from three cities was analyzed for total arsenic, iAs, methylarsonate (MA), dimethylarsinate, and nitarsone, which were compared across label type and month of purchase. Turkey consumption was estimated from NHANES data to estimate daily arsenic exposures for adults and children 4-30 months of age and cancer risks among adult consumers. Turkey meat from conventional producers not prohibiting nitarsone use showed increased mean levels of iAs (0.64 μg/kg) and MA (5.27 μg/kg) compared with antibiotic-free and organic meat (0.39 μg/kg and 1.54 μg/kg, respectively) and meat from conventional producers prohibiting nitarsone use (0.33 μg/kg and 0.28 μg/kg, respectively). Samples with measurable nitarsone had the highest mean iAs and MA (0.92 μg/kg and 10.96 μg/kg, respectively). Nitarsone was higher in October samples than in March samples, possibly resulting from increased summer use. Based on mean iAs concentrations in samples from conventional producers with no known policy versus policies prohibiting nitarsone, estimated lifetime daily consumption by an 80-kg adult, and a recently proposed cancer slope factor, we estimated that use of nitarsone by all turkey producers would result in 3.1 additional cases of bladder or lung cancer per 1,000,000 consumers. Nitarsone use can expose turkey consumers to iAs and MA. The results of our study support the U.S. Food and Drug Administration's removal of nitarsone from the U.S. market and further support its removal from the global marketplace

Transient and permanent changes in DNA methylation patterns in inorganic arsenic-mediated epithelial-to-mesenchymal transition

PubMed Central

Eckstein, Meredith; Rea, Matthew; Fondufe-Mittendorf, Yvonne N.

2017-01-01

Chronic low dose inorganic arsenic exposure causes cells to take on an epithelial-to-mesenchymal phenotype, which is a crucial process in carcinogenesis. Inorganic arsenic is not a mutagen and thus epigenetic alterations have been implicated in this process. Indeed, during the epithelial-to-mesenchymal transition, morphologic changes to cells correlate with changes in chromatin structure and gene expression, ultimately driving this process. However, studies on the effects of inorganic arsenic exposure/withdrawal on the epithelial-to-mesenchymal transition and the impact of epigenetic alterations in this process are limited. In this study we used high-resolution microarray analysis to measure the changes in DNA methylation in cells undergoing inorganic arsenic-induced epithelial-to-mesenchymal transition, and on the reversal of this process, after removal of the inorganic arsenic exposure. We found that cells exposed to chronic, low-dose inorganic arsenic exposure showed 30,530 sites were differentially methylated, and with inorganic arsenic withdrawal several differential methylated sites were reversed, albeit not completely. Furthermore, these changes in DNA methylation mainly correlated with changes in gene expression at most sites tested but not at all. This study suggests that DNA methylation changes on gene expression are not clear-cut and provide a platform to begin to uncover the relationship between DNA methylation and gene expression, specifically within the context of inorganic arsenic treatment. PMID:28336213

Total and inorganic arsenic in natural and aquacultural freshwater fish in Thailand: a comparative study.

PubMed

Ruangwises, Nongluck; Saipan, Piyawat; Ruangwises, Suthep

2012-12-01

Total and inorganic arsenic were determined in 108 samples of four freshwater fish species collected from natural water sources and aquaculture systems in the central region of Thailand between March and May 2010. Concentrations of total and inorganic arsenic (dry wt) and percentages of inorganic arsenic in four aquacultural fish species were not significantly different from those found in natural fish. Inorganic arsenic levels found in the four fish species from both sources in this study were much lower than the Thai regulatory standard of 2 μg/g, and hence are considered safe for human consumption.

Transient and permanent changes in DNA methylation patterns in inorganic arsenic-mediated epithelial-to-mesenchymal transition.

PubMed

Eckstein, Meredith; Rea, Matthew; Fondufe-Mittendorf, Yvonne N

2017-09-15

Chronic low dose inorganic arsenic exposure causes cells to take on an epithelial-to-mesenchymal phenotype, which is a crucial process in carcinogenesis. Inorganic arsenic is not a mutagen and thus epigenetic alterations have been implicated in this process. Indeed, during the epithelial-to-mesenchymal transition, morphologic changes to cells correlate with changes in chromatin structure and gene expression, ultimately driving this process. However, studies on the effects of inorganic arsenic exposure/withdrawal on the epithelial-to-mesenchymal transition and the impact of epigenetic alterations in this process are limited. In this study we used high-resolution microarray analysis to measure the changes in DNA methylation in cells undergoing inorganic arsenic-induced epithelial-to-mesenchymal transition, and on the reversal of this process, after removal of the inorganic arsenic exposure. We found that cells exposed to chronic, low-dose inorganic arsenic exposure showed 30,530 sites were differentially methylated, and with inorganic arsenic withdrawal several differential methylated sites were reversed, albeit not completely. Furthermore, these changes in DNA methylation mainly correlated with changes in gene expression at most sites tested but not at all. This study suggests that DNA methylation changes on gene expression are not clear-cut and provide a platform to begin to uncover the relationship between DNA methylation and gene expression, specifically within the context of inorganic arsenic treatment. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

IRIS Toxicological Review for Inorganic Arsenic (Scoping and Problem Formulation Materials)

EPA Science Inventory

In November 2012, EPA released scoping and problem formulation materials for the IRIS assessment of inorganic arsenic for public comment and discussion. The scoping information was based on input from EPA's program and regional offices and was provided for informational purposes....

Arsenic speciation in rice and risk assessment of inorganic arsenic in Taiwan population.

PubMed

Chen, Hsiu-Ling; Lee, Ching-Chang; Huang, Winn-Jung; Huang, Han-Ting; Wu, Yi-Chen; Hsu, Ya-Chen; Kao, Yi-Ting

2016-03-01

This study assessed the total arsenic content and arsenic speciation in rice to determine the health risks associated with rice consumption in various age-gender subgroups in Taiwan. The average total arsenic levels in white rice and brown rice were 116.6 ± 39.2 and 215.5 ± 63.5 ng/g weight (n = 51 and 13), respectively. The cumulative cancer risk among males was 10.4/100,000. The highest fraction of inorganic/total arsenic content in white rice ranged from 76.9 to 88.2 % and from 81.0 to 96.5 % in brown rice. The current study found different arsenic speciation of rice in southern Taiwan, where the famous blackfoot disease has been reported compared with arsenic speciation from other Taiwan areas. Therefore, rice and other grains should be further monitored in southern Taiwan to evaluate whether arsenic contamination is well controlled in this area.

Rapid Reduction in Breast Cancer Mortality With Inorganic Arsenic in Drinking Water

PubMed Central

Smith, Allan H.; Marshall, Guillermo; Yuan, Yan; Steinmaus, Craig; Liaw, Jane; Smith, Martyn T.; Wood, Lily; Heirich, Marissa; Fritzemeier, Rebecca M.; Pegram, Mark D.; Ferreccio, Catterina

2014-01-01

Background Arsenic trioxide is effective in treating promyelocytic leukemia, and laboratory studies demonstrate that arsenic trioxide causes apoptosis of human breast cancer cells. Region II in northern Chile experienced very high concentrations of inorganic arsenic in drinking water, especially in the main city Antofagasta from 1958 until an arsenic removal plant was installed in 1970. Methods We investigated breast cancer mortality from 1950 to 2010 among women in Region II compared to Region V, which had low arsenic water concentrations. We conducted studies on human breast cancer cell lines and compared arsenic exposure in Antofagasta with concentrations inducing apoptosis in laboratory studies. Findings Before 1958, breast cancer mortality rates were similar, but in 1958–1970 the rates in Region II were half those in Region V (rate ratio RR = 0.51, 95% CI 0.40–0.66; p < 0.0001). Women under the age of 60 experienced a 70% reduction in breast cancer mortality during 1965–1970 (RR = 0.30, 0.17–0.54; p < 0.0001). Breast cancer cell culture studies showed apoptosis at arsenic concentrations close to those estimated to have occurred in people in Region II. Interpretation We found biologically plausible major reductions in breast cancer mortality during high exposure to inorganic arsenic in drinking water which could not be attributed to bias or confounding. We recommend clinical trial assessment of inorganic arsenic in the treatment of advanced breast cancer. PMID:25580451

29 CFR 1910.1018 - Inorganic arsenic.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Coveralls or similar full-body work clothing; (ii) Gloves, and shoes or coverlets; (iii) Face shields or... possibility of skin or eye irritation from exposure to inorganic arsenic wash their hands and face prior to... well your respirator fits your face is very important, your employer is required to conduct fit tests...

29 CFR 1910.1018 - Inorganic arsenic.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Coveralls or similar full-body work clothing; (ii) Gloves, and shoes or coverlets; (iii) Face shields or... possibility of skin or eye irritation from exposure to inorganic arsenic wash their hands and face prior to... well your respirator fits your face is very important, your employer is required to conduct fit tests...

Dietary intake of total and inorganic arsenic by adults in arsenic-contaminated area of Ron Phibun district, Thailand.

PubMed

Ruangwises, Suthep; Saipan, Piyawat

2010-03-01

Ron Phibun District, approximately 800 km south of Bangkok, is the site of tin mines operated almost 100 years ago. As a result of mining activities, arsenic contaminated the soil and groundwater of the district. The specific aim of this study was to estimate the dietary intakes of total and inorganic arsenic in 20 adults (10 males and 10 females) residing in Ron Phibun District by a duplicate food approach for 7-consecutive days. The weekly intake rates of inorganic arsenic ranged from 5.54 to 13.3 microg/kg BW for males and 6.11-12.1 microg/kg BW for females.

Multiple inorganic toxic substances contaminating the groundwater of Myingyan Township, Myanmar: arsenic, manganese, fluoride, iron, and uranium.

PubMed

Bacquart, Thomas; Frisbie, Seth; Mitchell, Erika; Grigg, Laurie; Cole, Christopher; Small, Colleen; Sarkar, Bibudhendra

2015-06-01

In South Asia, the technological and societal shift from drinking surface water to groundwater has resulted in a great reduction of acute diseases due to water borne pathogens. However, arsenic and other naturally occurring inorganic toxic substances present in groundwater in the region have been linked to a variety of chronic diseases, including cancers, heart disease, and neurological problems. Due to the highly specific symptoms of chronic arsenic poisoning, arsenic was the first inorganic toxic substance to be noticed at unsafe levels in the groundwater of West Bengal, India and Bangladesh. Subsequently, other inorganic toxic substances, including manganese, uranium, and fluoride have been found at unsafe levels in groundwater in South Asia. While numerous drinking water wells throughout Myanmar have been tested for arsenic, relatively little is known about the concentrations of other inorganic toxic substances in Myanmar groundwater. In this study, we analyzed samples from 18 drinking water wells (12 in Myingyan City and 6 in nearby Tha Pyay Thar Village) and 2 locations in the Ayeyarwaddy River for arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, fluoride, iron, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, uranium, vanadium, and zinc. Concentrations of arsenic, manganese, fluoride, iron, or uranium exceeded health-based reference values in most wells. In addition, any given well usually contained more than one toxic substance at unsafe concentrations. While water testing and well sharing could reduce health risks, none of the wells sampled provide water that is entirely safe with respect to inorganic toxic substances. It is imperative that users of these wells, and users of other wells that have not been tested for multiple inorganic toxic substances throughout the region, be informed of the need for drinking water testing and the health consequences of drinking water contaminated with inorganic toxic

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water.

PubMed

Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R; Thach, Thu-Trang; McCarty, Kathleen M; Yeckel, Catherine W

2013-02-01

Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Unexposed (n = 16) and exposed (n = 19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (> 20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2 ± 30.4 and 1.0 ± 0.2 μg/l for the exposed and unexposed groups, respectively (P < 0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P = 0.035) and cold stress (73.7 vs. 37.5%; P = 0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P = 0.035). Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk.

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water

PubMed Central

Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R.; Thach, Thu-Trang; Mccarty, Kathleen M.; Yeckel, Catherine W.

2012-01-01

Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. Objective We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Methods Unexposed (n=16) and exposed (n=19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Results Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (>20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2±30.4 and 1.0±0.2 μg/l for the exposed and unexposed groups, respectively (P<0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P=0.035) and cold stress (73.7 vs. 37.5%; P=0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P=0.035). Conclusions Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk. PMID:23203141

Determination of Inorganic Arsenic in a Wide Range of Food Matrices using Hydride Generation - Atomic Absorption Spectrometry.

PubMed

de la Calle, Maria B; Devesa, Vicenta; Fiamegos, Yiannis; Vélez, Dinoraz

2017-09-01

The European Food Safety Authority (EFSA) underlined in its Scientific Opinion on Arsenic in Food that in order to support a sound exposure assessment to inorganic arsenic through diet, information about distribution of arsenic species in various food types must be generated. A method, previously validated in a collaborative trial, has been applied to determine inorganic arsenic in a wide variety of food matrices, covering grains, mushrooms and food of marine origin (31 samples in total). The method is based on detection by flow injection-hydride generation-atomic absorption spectrometry of the iAs selectively extracted into chloroform after digestion of the proteins with concentrated HCl. The method is characterized by a limit of quantification of 10 µg/kg dry weight, which allowed quantification of inorganic arsenic in a large amount of food matrices. Information is provided about performance scores given to results obtained with this method and which were reported by different laboratories in several proficiency tests. The percentage of satisfactory results obtained with the discussed method is higher than that of the results obtained with other analytical approaches.

Health risk assessment of inorganic arsenic intake of Ronphibun residents via duplicate diet study.

PubMed

Saipan, Piyawat; Ruangwises, Suthep

2009-06-01

To assess health risk from exposure to inorganic arsenic via duplicate portion sampling method in Ronphibun residents. A hundred and forty samples (140 subject-days) were collected from participants in Ronphibun sub-district. Inorganic arsenic in duplicate diet sample was determined by acid digestion and hydride generation-atomic absorption spectrometry. Deterministic risk assessment is referenced throughout the present paper using United States Environmental Protection Agency (U.S. EPA) guidelines. The average daily dose and lifetime average daily dose of inorganic arsenic via duplicate diet were 0.0021 mg/kg/d and 0.00084 mg/kg/d, respectively. The risk estimates in terms of hazard quotient was 6.98 and cancer risk was 1.26 x 10(-3). The results of deterministic risk characterization both hazard quotient and cancer risk from exposure inorganic arsenic in duplicate diets were greater than safety risk levels of hazard quotient (1) and cancer risk (1 x 10(-4)).

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...

Quantitative Mass Spectrometry Reveals Changes in Histone H2B Variants as Cells Undergo Inorganic Arsenic-Mediated Cellular Transformation*

PubMed Central

Rea, Matthew; Jiang, Tingting; Eleazer, Rebekah; Eckstein, Meredith; Marshall, Alan G.; Fondufe-Mittendorf, Yvonne N.

2016-01-01

Exposure to inorganic arsenic, a ubiquitous environmental toxic metalloid, leads to carcinogenesis. However, the mechanism is unknown. Several studies have shown that inorganic arsenic exposure alters specific gene expression patterns, possibly through alterations in chromatin structure. While most studies on understanding the mechanism of chromatin-mediated gene regulation have focused on histone post-translational modifications, the role of histone variants remains largely unknown. Incorporation of histone variants alters the functional properties of chromatin. To understand the global dynamics of chromatin structure and function in arsenic-mediated carcinogenesis, analysis of the histone variants incorporated into the nucleosome and their covalent modifications is required. Here we report the first global mass spectrometric analysis of histone H2B variants as cells undergo arsenic-mediated epithelial to mesenchymal transition. We used electron capture dissociation-based top-down tandem mass spectrometry analysis validated with quantitative reverse transcription real-time polymerase chain reaction to identify changes in the expression levels of H2B variants in inorganic arsenic-mediated epithelial-mesenchymal transition. We identified changes in the expression levels of specific histone H2B variants in two cell types, which are dependent on dose and length of exposure of inorganic arsenic. In particular, we found increases in H2B variants H2B1H/1K/1C/1J/1O and H2B2E/2F, and significant decreases in H2B1N/1D/1B as cells undergo inorganic arsenic-mediated epithelial-mesenchymal transition. The analysis of these histone variants provides a first step toward an understanding of the functional significance of the diversity of histone structures, especially in inorganic arsenic-mediated gene expression and carcinogenesis. PMID:27169413

Dietary intake of total and inorganic arsenic by adults in arsenic-contaminated Dan Chang district, Thailand, using duplicate food approach.

PubMed

Ruangwises, Suthep; Ruangwises, Nongluck; Saipan, Piyawat

2011-02-01

Dan Chang district, approximately 100 km west of Bangkok, was a site of tin mines operated almost 40 years ago. Mining operations caused arsenic contamination in soil, surface water, and groundwater within the district. The specific aim of this study was to estimate the dietary intakes of total and inorganic arsenic in 60 adults (30 males and 30 females) residing in Dan Chang district, using a duplicate food approach. The daily intake rates of inorganic arsenic ranged from 0.496 to 1.817 μg/kg BW for males and 0.342 to 1.778 μg/kg BW for females.

Low-level inorganic arsenic exposure and neuropsychological functioning in American Indian elders.

PubMed

Carroll, Clint R; Noonan, Carolyn; Garroutte, Eva M; Navas-Acien, Ana; Verney, Steven P; Buchwald, Dedra

2017-07-01

Inorganic arsenic at high and prolonged doses is highly neurotoxic. Few studies have evaluated whether long-term, low-level arsenic exposure is associated with neuropsychological functioning in adults. To investigate the association between long-term, low-level inorganic arsenic exposure and neuropsychological functioning among American Indians aged 64-95. We assessed 928 participants in the Strong Heart Study by using data on arsenic species in urine samples collected at baseline (1989-1991) and results of standardized tests of global cognition, executive functioning, verbal learning and memory, fine motor functioning, and speed of mental processing administered during comprehensive follow-up evaluations in 2009-2013. We calculated the difference in neuropsychological functioning for a 10% increase in urinary arsenic with adjustment for sex, age, education, and study site. The sum of inorganic and methylated arsenic species (∑As) in urine was associated with limited fine motor functioning and processing speed. A 10% increase in ∑As was associated with a .10 (95% CI -.20, -.01) decrease on the Finger Tapping Test for the dominant hand and a .13 decrease (95% CI -.21, -.04) for the non-dominant hand. Similarly, a 10% increase in ∑As was associated with a .15 (95% CI -.29, .00) decrease on the Wechsler Adult Intelligence Scale-Fourth Edition Coding Subtest. ∑As was not associated with other neuropsychological functions. Findings indicate an adverse association between increased urinary arsenic fine motor functioning and processing speed, but not with other neuropsychological functioning, among elderly American Indians. Copyright © 2017 Elsevier Inc. All rights reserved.

Automated system for on-line determination of dimethylarsinic and inorganic arsenic by hydride generation-atomic fluorescence spectrometry.

PubMed

Chaparro, L L; Ferrer, L; Cerdà, V; Leal, L O

2012-09-01

A multisyringe flow-injection approach has been coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS) with UV photo-oxidation for dimethylarsinic (DMA), inorganic As and total As determination, depending on the pre-treatment given to the sample (extraction or digestion). The implementation of a UV lamp allows on-line photo-oxidation of DMA and the following arsenic detection, whereas a bypass leads the flow directly to the HG-AFS system, performing inorganic arsenic determination. DMA concentration is calculated by the difference of total inorganic arsenic and measurement of the photo-oxidation step. The detection limits for DMA and inorganic arsenic were 0.09 and 0.47 μg L(-1), respectively. The repeatability values accomplished were of 2.4 and 1.8%, whereas the injection frequencies were 24 and 28 injections per hour for DMA and inorganic arsenic, respectively. This method was validated by means of a solid reference material BCR-627 (muscle of tuna) with good agreement with the certified values. Satisfactory results for DMA and inorganic arsenic determination were obtained in several water matrices. The proposed method offers several advantages, such as increasing the sampling frequency, low detection limits and decreasing reagents and sample consumption, which leads to lower waste generation.

Inorganic arsenic levels in rice milk exceed EU and US drinking water standards.

PubMed

Meharg, Andrew A; Deacon, Claire; Campbell, Robert C J; Carey, Anne-Marie; Williams, Paul N; Feldmann, Joerg; Raab, Andrea

2008-04-01

Under EU legislation, total arsenic levels in drinking water should not exceed 10 microg l(-1), while in the US this figure is set at 10 microg l(-1) inorganic arsenic. All rice milk samples analysed in a supermarket survey (n = 19) would fail the EU limit with up to 3 times this concentration recorded, while out of the subset that had arsenic species determined (n = 15), 80% had inorganic arsenic levels above 10 microg l(-1), with the remaining 3 samples approaching this value. It is a point for discussion whether rice milk is seen as a water substitute or as a food, there are no EU or US food standards highlighting the disparity between water and food regulations in this respect.

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

Toxicity of so-called edible hijiki seaweed (Sargassum fusiforme) containing inorganic arsenic.

PubMed

Yokoi, Katsuhiko; Konomi, Aki

2012-07-01

The UK Food Standards Agency and its counterparts in other countries have warned consumers not to eat hijiki (Sargassum fusiforme; synonym Hizikia fusiformis), a Sargasso seaweed, because it contains large amounts of inorganic arsenic. We investigated dietary exposure of hijiki in weaning male F344/N rats fed an AIN-93G diet supplemented with 3% (w/w) hijiki powder for 7 weeks, compared with those fed only an AIN-93G diet. Body weight, body temperature, blood and tissue arsenic concentrations, plasma biochemistry and hematological parameters were measured. We found that feeding rats a 3% hijiki diet led to a marked accumulation of arsenic in blood and tissues, and evoked a high body temperature and abnormal blood biochemistry including elevated plasma alkaline phosphatase activity and inorganic phosphorus, consistent with arsenic poisoning. These findings should prompt further investigations to identify the health hazards related to consumption of hijiki and related Sargassum species in humans. Copyright © 2012 Elsevier Inc. All rights reserved.

IRIS Toxicological Review of Inorganic Arsenic (Preliminary Assessment Materials)

EPA Science Inventory

In April 2014, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for inorganic arsenic (iAs) to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA ...

Developmental and reproductive toxicity of inorganic arsenic: animal studies and human concerns.

PubMed

Golub, M S; Macintosh, M S; Baumrind, N

1998-01-01

Information on the reproductive and developmental toxicity of inorganic arsenic is available primarily from studies in animals using arsenite and arsenate salts and arsenic trioxide. Inorganic arsenic has been extensively studied as a teratogen in animals. Data from animal studies demonstrate that arsenic can produce developmental toxicity, including malformation, death, and growth retardation, in four species (hamsters, mice, rats, rabbits). A characteristic pattern of malformations is produced, and the developmental toxicity effects are dependent on dose, route, and the day of gestation when exposure occurs. Studies with gavage and diet administration indicate that death and growth retardation are produced by oral arsenic exposure. Arsenic is readily transferred to the fetus and produces developmental toxicity in embryo culture. Animal studies have not identified an effect of arsenic on fertility in males or females. When females were dosed chronically for periods that included pregnancy, the primary effect of arsenic on reproduction was a dose-dependent increase in conceptus mortality and in postnatal growth retardation. Human data are limited to a few studies of populations exposed to arsenic from drinking water or from working at or living near smelters. Associations with spontaneous abortion and stillbirth have been reported in more than one of these studies, but interpretation of these studies is complicated because study populations were exposed to multiple chemicals. Thus, animal studies suggest that environmental arsenic exposures are primarily a risk to the developing fetus. In order to understand the implications for humans, attention must be given to comparative pharmacokinetics and metabolism, likely exposure scenarios, possible mechanisms of action, and the potential role of arsenic as an essential nutrient.

BIOMARKERS OF EXPOSURE: A CASE STUDY WITH INORGANIC ARSENIC

EPA Science Inventory

Inorganic arsenic (iAs) is a human toxicant and carcinogen that is found in the environment as a natural contaminant and from anthropogenic sources. Most mammalian species metabolize iAs by reduction to trivalent species followed by oxidative methylation to pentavalent species. ...

Accuracy of a method based on atomic absorption spectrometry to determine inorganic arsenic in food: Outcome of the collaborative trial IMEP-41.

PubMed

Fiamegkos, I; Cordeiro, F; Robouch, P; Vélez, D; Devesa, V; Raber, G; Sloth, J J; Rasmussen, R R; Llorente-Mirandes, T; Lopez-Sanchez, J F; Rubio, R; Cubadda, F; D'Amato, M; Feldmann, J; Raab, A; Emteborg, H; de la Calle, M B

2016-12-15

A collaborative trial was conducted to determine the performance characteristics of an analytical method for the quantification of inorganic arsenic (iAs) in food. The method is based on (i) solubilisation of the protein matrix with concentrated hydrochloric acid to denature proteins and allow the release of all arsenic species into solution, and (ii) subsequent extraction of the inorganic arsenic present in the acid medium using chloroform followed by back-extraction to acidic medium. The final detection and quantification is done by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). The seven test items used in this exercise were reference materials covering a broad range of matrices: mussels, cabbage, seaweed (hijiki), fish protein, rice, wheat, mushrooms, with concentrations ranging from 0.074 to 7.55mgkg(-1). The relative standard deviation for repeatability (RSDr) ranged from 4.1 to 10.3%, while the relative standard deviation for reproducibility (RSDR) ranged from 6.1 to 22.8%. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Notification of SAB Workgroup Public Meeting for the Toxicological Review of Inorganic Arsenic

EPA Pesticide Factsheets

Organic Arsenical Products Task Force (OAPTF), a group of registrants of pesticide products that contain monosodium methanearsonate (MSMA), to request that the Science Advisory Board (SAB) reschedule the public meeting of a workgroup to conduct a review of the draft document entitled Toxicological Review of Inorganic Arsenic

METABOLISM AS A DETERMINING FACTOR IN ACUTE AND CHRONIC TOXICITY OF INORGANIC ARSENIC

EPA Science Inventory

The metabolism of inorganic arsenic (iAs) in humans involves reduction of As(V)-species to trivalency and oxidative methylation of As(III)-species. In this pathway, iAs is converted to methylarsenic (MAs) and dimethyl arsenic (DMAs) metabolites that contain As(III) or As(V). Rec...

Inorganic arsenic impairs differentiation and functions of human dendritic cells

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

Macoch, Mélinda; Morzadec, Claudie; Fardel, Olivier

2013-01-15

Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis.more » Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells

A rapid monitoring method for inorganic arsenic in rice flour using reversed phase-high performance liquid chromatography-inductively coupled plasma mass spectrometry.

PubMed

Narukawa, Tomohiro; Chiba, Koichi; Sinaviwat, Savarin; Feldmann, Jörg

2017-01-06

A new rapid monitoring method by means of high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) following the heat-assisted extraction was developed for measurement of total inorganic arsenic species in rice flour. As(III) and As(V) eluted at the same retention time and completely separated from organoarsenic species by an isocratic elution program on a reversed phase column. Therefore, neither ambiguous oxidation of arsenite to arsenate nor the integration of two peaks were necessary to determine directly the target analyte inorganic arsenic. Rapid injection allowed measuring 3 replicates within 6min and this combined with a quantitative extraction of all arsenic species from rice flour by a 15min HNO 3 -H 2 O 2 extraction makes this the fastest laboratory based method for inorganic arsenic in rice flour. Copyright © 2016 Elsevier B.V. All rights reserved.

Occurrence of inorganic arsenic in edible Shiitake (Lentinula edodes) products.

PubMed

Llorente-Mirandes, Toni; Barbero, Mercedes; Rubio, Roser; López-Sánchez, José Fermín

2014-09-01

The present study reports arsenic speciation analysis in edible Shiitake (Lentinula edodes) products. The study focused on the extraction, and accurate quantification of inorganic arsenic (iAs), the most toxic form of arsenic, which was selectively separated and determined using anion exchange LC-ICPMS. A wide variety of edible Shiitake products (fresh mushrooms, food supplements, canned and dehydrated) were purchased and analysed. A cultivated Shiitake grown under controlled conditions was also analysed. The extraction method showed satisfactory extraction efficiencies (>90%) and column recoveries (>85%) for all samples. Arsenic speciation revealed that iAs was the major As compound up to 1.38 mg As kg(-1) dm (with a mean percentage of 84% of the total arsenic) and other organoarsenicals were found as minor species. Shiitake products had high proportions of iAs and therefore should not be ignored as potential contributors to dietary iAs exposure in populations with a high intake of Shiitake products. Copyright © 2014 Elsevier Ltd. All rights reserved.

Changes in Serum Adiponectin in Mice Chronically Exposed to Inorganic Arsenic in Drinking Water.

PubMed

Song, Xuanbo; Li, Ying; Liu, Junqiu; Ji, Xiaohong; Zhao, Lijun; Wei, Yudan

2017-09-01

Cardiovascular disease and diabetes mellitus are prominent features of glucose and lipid metabolism disorders. Adiponectin is a key adipokine that is largely involved in glucose and lipid metabolism processes. A growing body of evidence suggests that chronic exposure to inorganic arsenic is associated with cardiovascular disease and diabetes mellitus. We hypothesized that arsenic exposure may increase the risk of cardiovascular disease and diabetes mellitus by affecting the level of adiponectin. In this study, we examined serum adiponectin levels, as well as serum levels of metabolic measures (including fasting blood glucose, insulin, total cholesterol, triglyceride, and high-density lipoprotein (HDL)-cholesterol) in C57BL/6 mice exposed to inorganic arsenic in drinking water (5 and 50 ppm NaAsO 2 ) for 18 weeks. Body mass and adiposity were monitored throughout the study. We found no significant changes in serum insulin and glucose levels in mice treated with arsenic for 18 weeks. However, arsenic exposure decreased serum levels of adiponectin, triglyceride, and HDL-cholesterol. Further, an inverse relationship was observed between urinary concentrations of total arsenic and serum levels of adiponectin. This study suggests that arsenic exposure could disturb the metabolism of lipids and increase the risk of cardiovascular disease by reducing the level of adiponectin.

Effects of Inorganic Arsenic, Methylated Arsenicals, and Arsenobetaine on Atherosclerosis in the apoE−/− Mouse Model and the Role of As3mt-Mediated Methylation

PubMed Central

Negro Silva, Luis Fernando; Lemaire, Maryse; Lemarié, Catherine A.; Plourde, Dany; Bolt, Alicia M.; Chiavatti, Christopher; Bohle, D. Scott; Slavkovich, Vesna; Graziano, Joseph H.; Lehoux, Stéphanie

2017-01-01

Background: Arsenic is metabolized through a series of oxidative methylation reactions by arsenic (3) methyltransferase (As3MT) to yield methylated intermediates. Although arsenic exposure is known to increase the risk of atherosclerosis, the contribution of arsenic methylation and As3MT remains undefined. Objectives: Our objective was to define whether methylated arsenic intermediates were proatherogenic and whether arsenic biotransformation by As3MT was required for arsenic-enhanced atherosclerosis. Methods: We utilized the apoE−/− mouse model to compare atherosclerotic plaque size and composition after inorganic arsenic, methylated arsenical, or arsenobetaine exposure in drinking water. We also generated apoE−/−/As3mt−/− double knockout mice to test whether As3MT-mediated biotransformation was required for the proatherogenic effects of inorganic arsenite. Furthermore, As3MT expression and function were assessed in in vitro cultures of plaque-resident cells. Finally, bone marrow transplantation studies were performed to define the contribution of As3MT-mediated methylation in different cell types to the development of atherosclerosis after inorganic arsenic exposure. Results: We found that methylated arsenicals, but not arsenobetaine, are proatherogenic and that As3MT is required for arsenic to induce reactive oxygen species and promote atherosclerosis. Importantly, As3MT was expressed and functional in multiple plaque-resident cell types, and transplant studies indicated that As3MT is required in extrahepatic tissues to promote atherosclerosis. Conclusion: Taken together, our findings indicate that As3MT acts to promote cardiovascular toxicity of arsenic and suggest that human AS3MT SNPs that correlate with enzyme function could predict those most at risk to develop atherosclerosis among the millions that are exposed to arsenic. https://doi.org/10.1289/EHP806 PMID:28728140

RE: Notification of SAB Workgroup Public Meeting for the Toxicological Review of Inorganic Arsenic

EPA Pesticide Factsheets

Request from the Organic Arsenical Products Task Force for the Science Advisory Board to reschedule the public meeting of a workgroup to conduct a review of the draft document Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System (IRIS).

Difference of toxicity and accumulation of methylated and inorganic arsenic in arsenic-hyperaccumulating and -hypertolerant plants.

PubMed

Huang, Ze-Chun; Chen, Tong-Bin; Lei, Mei; Liu, Ying-Ru; Hu, Tian-Dou

2008-07-15

The arsenic (As) hyperaccumulators, Pteris vittata and Pteris cretica and an As-tolerant plant Boehmeria nivea, were selected to compare the toxicity, uptake, and transportation of inorganic arsenate (As(V)) and its methylated counterpart dimethylarsinic acid (DMA). The XANES method was used to elucidate the effect of As species transformation on As toxicity and accumulation characteristics. Significantly higher toxicity and lower accumulation of DMAthan inorganic As(V) was shown in the As hyperaccumulators and the As-tolerant plant. Reduction of As(V) was commonly found in the plants. Arsenic complexation with thiols, which have less mobility in plants and usually occur in As-tolerant plants, was also found in rhizoids of P. cretica. Plants with greater ability to form As-thiolate have lower ability for upward transport of As. Demethylation of DMA occurred in the three plants. The DMA component decreased from the rhizoids to the fronds in both hyperaccumulators, while this tendency is reverse in B. nivea.

IRIS Toxicological Review of Inorganic Arsenic (Cancer) ...

EPA Pesticide Factsheets

EPA's Science Advisory Board (SAB) conducted a review of the scientific basis supporting the human health cancer hazard and dose-response assessment of inorganic arsenic that will appear on the Integrated Risk Information System (IRIS) database. EPA revised the assessment and is now returning the assessment to the SAB and releasing the document to the public for a focused review of EPA's responses to the SAB recommendations. This draft IRIS health assessment addresses only cancer human health effects that may result from chronic exposure to this chemical.

Dilution of rice with other gluten free grains to lower inorganic arsenic in foods for young children in response to European Union regulations provides impetus to setting stricter standards

PubMed Central

Donaldson, Emily; Signes-Pastor, Antonio J.

2018-01-01

There has been an increasing realisation that young infants are exposed to elevated concentrations of the carcinogen inorganic arsenic, relative to adults. This is because many infant food products are rice based, and rice is ~10-fold elevated in inorganic arsenic compared to most other foods. The European Commission (EC) has acted on this concern setting stricter standards for infants, 100 μg of inorganic arsenic per kg of food (100 μg/kg), as compared to adults (200 μg/kg), for rice based foods, a law that was brought into place in 1st January 2016. Here we investigate how this law has impacted on inorganic arsenic in baby food products in the UK market, and compare the findings to previous baby food surveys taken before and just after the law came into place. We find that for a wide range of UK infant products that the new regulations are being adhered to, with all samples surveyed, being under 100 μg/kg inorganic arsenic. The prevalence of pure rice products had decreased in the UK, and there appears to be careful sourcing of the rice used in these products to ensure conformity with regulations. There has been an increased presence of mixed cereal products, with rice and maize as the main ingredient, appearing on the UK market, with varying rice contents for infant porridges, cakes and mueslis, with the latter being a relatively innovative product for infant foods. There was a highly significant correlation (P<0.0001) between rice content and inorganic arsenic concentration across all infant foods. When UK infant rice cakes, breakfast cereals and porridges were compare to their general, i.e. not labelled specifically for being for infant consumption, equivalent it was found that the adult foods generally exceeded the 100 μg/kg inorganic arsenic standard for infant foods. Thus, infants should not be given rice products not specifically labelled as being for them if a lower inorganic arsenic diet is to be maintained. PMID:29547635

ORGANIC AND INORGANIC ARSENICALS SENSITIZE HUMAN BRONCHIAL EPITHELIAL CELLS TO HYDROGEN PEROXIDE-INDUCED DNA DAMAGE

EPA Science Inventory

The lungs are a target organ for arsenic carcinogenesis, however, its mechanism of action remains unclear. Furthermore, it has been suggested that inorganic arsenic (iAs) can potentiate DNA damage induced by other agents. Once inside the human body iAs generally undergoes two ...

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

Estimation of Total and Inorganic Arsenic Intake from the Diet in Korean Adults.

PubMed

Seo, Mi-Na; Lee, Seul-Gi; Eom, Sang-Yong; Kim, Jeongseon; Oh, Se-Young; Kwon, Ho-Jang; Kim, Heon; Choi, Byung-Sun; Yu, Il-Je; Park, Jung-Duck

2016-05-01

Arsenic (As) is a major environmental pollutant and a known human carcinogen that is widely distributed in the air, soil, and water. General population is mainly exposed to As through drinking water and food from the contaminated water and soil. Arsenic in drinking water is generally well controlled now. This study was performed to estimate total and inorganic As intake and to determine the major contributing source in the Korean adult diet. The study subjects were 2117 healthy adults (922 males and 1195 females) who had not been occupationally exposed to As. Total dietary intake was studied using the 24-h recall method, which included 138 specific food items. The estimates of total As and inorganic As intake were based on total and inorganic As contents in each food item consumed during the last 24 h. Daily dietary intake was estimated to be 1373.6 g. Total As intake was estimated to be 145.4 µg As/day. Total dietary As intake was correlated with consumption of fish/shellfish, seaweeds, and grains. Approximately 87% of total dietary As intake was attributed to seafood, such as 105.5 µg As/day from fish/shellfish and 20.5 µg As/day from seaweeds. Inorganic As intake was estimated to be 10.4 µg As per day. Inorganic As intake was mainly provided by grains (6.4 µg As/day), followed by seaweeds and fish/shellfish. Our results indicate that seafood and grains are the main As dietary sources in Korean adults and that dietary As exposure may be associated with individual dietary habits and environmental As contamination among countries.

IRIS Toxicological Review of Inorganic Arsenic (Cancer) (2010 External Review Draft)

EPA Science Inventory

EPA's Science Advisory Board (SAB) conducted a review of the scientific basis supporting the human health cancer hazard and dose-response assessment of inorganic arsenic that will appear on the Integrated Risk Information System (IRIS) database. EPA revised the assessment and is...

IRIS Toxicological Review of Inorganic Arsenic (Cancer) (Interagency Science Consultation Draft)

EPA Science Inventory

On February 19, 2010, the draft IRIS Toxicological Review of Inorganic Arsenic (Cancer) external review draft document and the charge to external peer reviewers were released for public review and comment. The draft document and the charge to external peer reviewers were reviewed...

Exposure assessment of the population in Poland to the toxic effects of arsenic compounds present in rice and rice based products

PubMed

Mania, Monika; Rebeniak, Małgorzata; Szynal, Tomasz; Starska, Krystyna; Wojciechowska-Mazurek, Maria; Postupolski, Jacek

Rice is a staple food for many people in the world and an important ingredient for production of food for infants and young children. According to European Food Safety Authority (EFSA), cereals, primarily rice and rice products, are an important source of human exposure to inorganic arsenic, which has been classified by the International Agency for Research on Cancer (IARC) as group I carcinogen. Arsenic is present in rice and rice products mainly as an inorganic form being more toxic than organic compounds The aim of the study was to determine the total and inorganic arsenic content in rice, rice-based products including food for infants and young children available on the market in Poland and thus to estimate consumer exposure to inorganic arsenic from these groups of foodstuffs A total of 62 samples of rice and rice products from trade, including a group of rice products for infants and young children, were tested. Contents of total and inorganic arsenic were determined by using hydride generation atomic absorption spectrometry (HGAAS), after dry mineralization of samples and reduction of arsenic to arsenic hydride with sodium borohydride. To extract the inorganic arsenic forms, the samples were subjected to hydrolysis in concentrated HCl and then reduced in the presence of hydrobromic acid and hydrazine sulphate after which triple chloroform extractions and triple 1M HCl re-extractions were performed. Exposure of different groups of populations (adults and children), was estimated in relation to the Benchmark Dose Lower Confidence Limit (BMDL05) as set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) that resulted in a 0.5% increase in lung cancer (3.0 µg/kg body weight (b.w.) per day) Mean content of total and inorganic arsenic in investigated rice samples was 0.12 mg/kg (median: 0.09 mg/kg; 90th percentile 0.22 mg/kg) and 0.04 mg/kg (median: 0.03 mg/kg, 90th percentile 0.07 mg/kg). Brown rice was found to be more highly contaminated with both

Reproductive Effects Assessment Group's Report on the Mutagenicity of Inorganic Arsenic

EPA Science Inventory

Various inorganic compounds of arsenic have been tested for mutagenicity in a variety of test systems ranging in complexity from bacteria to peripheral lymphocytes of exposed human beings. Although a great deal of the data are contradictory, the weight of evidence supports the fo...

Paraoxonase 1 activity in subchronic low-level inorganic arsenic exposure through drinking water.

PubMed

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

2016-02-01

Epidemiological evidences indicate close association between inorganic arsenic exposure via drinking water and cardiovascular diseases. While the exact mechanism of this arsenic-mediated increase in cardiovascular risk factors remains enigmatic, epidemiological studies indicate a role for paraoxonase 1 (PON1) in cardiovascular diseases. To investigate the association between inorganic arsenic exposure and cardiovascular diseases, rats were exposed to sodium arsenite (trivalent; 50, 100, and 150 ppm As) and sodium arsenate (pentavalent; 100, 150, and 200 ppm As) in their drinking water for 12 weeks. PON1 activity towards paraoxon (PONase) and phenylacetate (AREase) in plasma, lipoproteins, hepatic, and brain microsomal fractions were determined. Inhibition of PONase and AREase in plasma and HDL characterized the effects of the two arsenicals. While the trivalent arsenite inhibited PONase by 33% (plasma) and 46% (HDL), respectively, the pentavalent arsenate inhibited the enzyme by 41 and 34%, respectively. AREase activity was inhibited by 52 and 48% by arsenite, whereas the inhibition amounted to 72 and 67%, respectively by arsenate. The pattern of inhibition in plasma and HDL indicates that arsenite induced a dose-dependent inhibition of PONase whereas arsenate induced a dose-dependent inhibition of AREase. In the VLDL + LDL, arsenate inhibited PONase and AREase while arsenite inhibited PONase. In the hepatic and brain microsomal fractions, only the PONase enzyme was inhibited by the two arsenicals. The inhibition was more pronounced in the hepatic microsomes where a 70% inhibition was observed at the highest dose of pentavalent arsenic. Microsomal cholesterol was increased by the two arsenicals resulting in increased cholesterol/phospholipid ratios. Our findings indicate that decreased PON1 activity observed in arsenic exposure may be an incipient biochemical event in the cardiovascular effects of arsenic. Modulation of PON1 activity by arsenic may also be

Total and inorganic arsenic in Iranian rice.

PubMed

Cano-Lamadrid, Marina; Munera-Picazo, Sandra; Burló, Francisco; Hojjati, Mohammad; Carbonell-Barrachina, Ángel A

2015-05-01

It is well known that arsenic (As) exposure, particularly to inorganic species (i-As), has adverse effects on humans. Nowadays, the European Union (EU) has still not regulated the maximum residue limit of As in commercial samples of rice and rice-based products, although it is actively working on the topic. The European Food Safety Authority (EFSA) is collecting data on total arsenic (t-As) and i-As from different rice-producing regions not only from EU countries but also from other parts of the world to finally set up this maximum threshold. As Iran is a rice-producing country, the aim of this work was to evaluate the contents of t-As and i-As in 15 samples of Iranian white, nonorganic, and aromatic rice collected from the most important rice-producing regions of the country. The means of t-As and i-As were 120 and 82 μg/kg, respectively. The experimental i-As mean in Iranian rice was below the Chinese standard for the i-As in rice, 150 μg/kg, and the Food and Agriculture Organization of the United Nations (FAO) limit, 200 μg/kg. Therefore, Iranian rice seems to have reasonable low i-As content and it is safe to be marketed in any market, including China and the EU. © 2015 Institute of Food Technologists®

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

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.

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.

Speciation analysis of inorganic arsenic by magnetic solid phase extraction on-line with inductively coupled mass spectrometry determination.

PubMed

Montoro Leal, P; Vereda Alonso, E; López Guerrero, M M; Cordero, M T Siles; Cano Pavón, J M; García de Torres, A

2018-07-01

Arsenic, one of the main environmental pollutants and potent natural poison, is a chemical element that is spread throughout the Earth's crust. It is well known that the toxicity of arsenic is highly dependent on its chemical forms. Generally, the inorganic species are more toxic than its organics forms, and As(III) is 60 times more toxic than As(V). In environmental waters, arsenic exists predominantly in two chemical forms: As(III) and As(V). In view of these facts, fast, sensitive, accurate and simple analytical methods for the speciation of inorganic arsenic in environmental waters are required. In this work, a new magnetic solid phase extraction with a hydride generation system was coupled on line with inductively coupled plasma mass spectrometry (MSPE-HG-ICP-MS). The new system was based on the retention of As(III) and As(V) in two knotted reactors filled with (Fe 3 O 4 ) magnetic nanoparticles functionalized with [1,5-bis (2-pyridyl) 3-sulfophenylmethylene] thiocarbonohydrazide (PSTH-MNPs). As(III) and total inorganic As were sequentially eluted in different reduction conditions. The concentration of As(V) was obtained by subtracting As(III) from total As. The system runs in a fully automated way and the method has proved to have a wide linear range and to be precise, sensitive and fast. The detection limits found were 2.7 and 3.2 ng/L for As(III) and total As, respectively; with relative standard deviations (RSDs) of 2.5% and 2.7% and a sample throughput of 14.4 h -1 . In order to validate the developed method, several certified reference samples of environmental waters including sea water, were analyzed and the determined values were in good agreement with the certified values. The proposed method was successfully applied to the speciation analysis of inorganic arsenic in well-water and sea water. Copyright © 2018 Elsevier B.V. All rights reserved.

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...

Total and inorganic arsenic in Mid-Atlantic marine fish and shellfish and implications for fish advisories.

PubMed

Greene, Richard; Crecelius, Eric

2006-10-01

Sampling was conducted in 2002 to determine the total concentration and chemical speciation of arsenic in several marine fish and shellfish species collected from the Delaware Inland Bays and the Delaware Estuary, both of which are important estuarine waterbodies in the US Mid-Atlantic region that support recreational and commercial fishing. Edible meats from summer flounder (Paralicthys dentatus), striped bass (Marone saxatilis), Atlantic croaker (Micropogonias undulates), and hard clam (Mercenaria mercenaria) were tested. Total arsenic was highest in summer flounder, followed by hard clam, then striped bass, and finally, Atlantic croaker. Total arsenic was higher in summer flounder collected during the spring, as these fish migrated into the Inland Bays from the continental shelf, compared with levels in summer flounder collected during the fall, after these fish had spent the summer in the Inland Bays. Similarly, striped bass collected in the early spring close to the ocean had higher total arsenic levels compared with levels detected in striped bass collected later during the year in waters with lower salinity. Speciation of arsenic revealed low concentrations (0.00048-0.02 microg/g wet wt) of toxic inorganic arsenic. Dimethylarsinic acid was more than an order of magnitude greater in hard clam meats than in the other species tested, a finding that was attributed to arsenic uptake by phytoplankton and subsequent dietary uptake by the clam. Risk assessment using the inorganic arsenic concentrations was used to conclude that a fish consumption advisory is not warranted.

A simple thermometric technique for reaction-rate determination of inorganic species, based on the iodide-catalysed cerium(IV)-arsenic(III) reaction.

PubMed

Grases, F; Forteza, R; March, J G; Cerda, V

1985-02-01

A very simple reaction-rate thermometric technique is used for determination of iodide (5-20 ng ml ), based on its catalytic action on the cerium(IV)-arsenic(III) reaction, and for determination of mercury(II) (1.5-10 ng ml ) and silver(I) (2-10 ng ml ), based on their inhibitory effect on this reaction. The reaction is followed by measuring the rate of temperature increase. The method suffers from very few interferences and is applied to determination of iodide in biological and inorganic samples, and Hg(II) and Ag(I) in pharmaceutical products.

Relationship between arsenic and selenium in workers occupationally exposed to inorganic arsenic.

PubMed

Janasik, Beata; Zawisza, Anna; Malachowska, Beata; Fendler, Wojciech; Stanislawska, Magdalena; Kuras, Renata; Wasowicz, Wojciech

2017-07-01

The interaction between arsenic (As) and selenium (Se) has been one of the most extensively studied. The antagonism between As and Se suggests that low Se status plays an important role in aggravating arsenic toxicity in diseases development. The objective of this study was to assess the Se contents in biological samples of inorganic As exposed workers (n=61) and in non-exposed subjects (n=52). Median (Me) total arsenic concentration in urine of exposed workers was 21.83μg/g creat. (interquartile range (IQR) 15.49-39.77) and was significantly higher than in the control group - (Me 3.75μg/g creat. (IQR 2.52-9.26), p<0.0001). The median serum Se concentrations in the study group and the control were: 54.20μg/l (IQR 44.2-73.10μg/l) and 55.45μg/l (IQR 38.5-69.60μg/l) respectively and did not differ significantly between the groups. In the exposed group we observed significantly higher urine concentrations of selenosugar 1 (SeSug 1) and selenosugar 3 (SeSug3) than in the control group Me: 1.68μg/g creat. (IQR 1.25-2.97 vs Me: 1.07μg/g creat. (IQR 0.86-1.29μg/g), p<0.0001 for SeSug1; Me: 0.45μg/g creat. (IQR 0.26-0.69) vs Me: 0.28μg/g creat. (IQR 0.17-0.45μg/g), p=0.0021). In the multivariate model, after adjusting to cofounders (age, BMI, job seniority time, consumption of fish and seafood and smoking habits) the high rate of arsenic urine wash out (measured as a sum of iAs+MMA+DMA) was significantly associated with the high total selenium urine excretion (B=0.14 (95%CI (confidence interval) 0.05-0.23)). Combination of both arsenic and selenium status to assess the risk of arsenic-induced diseases requires more studies with regard to both the analysis of speciation, genetics and the influence of factors such as nutritional status. Copyright © 2017 Elsevier GmbH. All rights reserved.

APPARENT SEXUAL DIFFERENCES IN METABOLISM OF INORGANIC ARSENIC IN HUMAN HEPATOCYTES

EPA Science Inventory

APPARENT SEXUAL DIFFERENCES IN METABOLISM OF INORGANIC ARSENIC IN HUMAN HEPATOCYTES. M Styblo1, G A Hamilton1, E L LeCluyse1 and D J Thomas2. 1University of North Carolina, Chapel Hill, NC, USA; 2US EPA, ORD, NHEERL, Research Triangle Park, NC, USA.
The liver is considered a m...

Relation of dietary inorganic arsenic exposure and urinary inorganic arsenic metabolites excretion in Japanese subjects.

PubMed

Oguri, Tomoko; Yoshinaga, Jun; Suzuki, Yayoi; Tao, Hiroaki; Nakazato, Tetsuya

2017-06-03

Inorganic arsenic (InAs) is a ubiquitous metalloid that has been shown to exert multiple adverse health outcomes. Urinary InAs and its metabolite concentration has been used as a biomarker of arsenic (As) exposure in some epidemiological studies, however, quantitative relationship between daily InAs exposure and urinary InAs metabolites concentration has not been well characterized. We collected a set of 24-h duplicated diet and spot urine sample of the next morning of diet sampling from 20 male and 19 female subjects in Japan from August 2011 to October 2012. Concentrations of As species in duplicated diet and urine samples were determined by using liquid chromatography-ICP mass spectrometry with a hydride generation system. Sum of the concentrations of urinary InAs and methylarsonic acid (MMA) was used as a measure of InAs exposure. Daily dietary InAs exposure was estimated to be 0.087 µg kg -1 day -1 (Geometric mean, GM), and GM of urinary InAs+MMA concentrations was 3.5 ng mL -1 . Analysis of covariance did not find gender-difference in regression coefficients as significant (P > 0.05). Regression equation Log 10 [urinary InAs+MMA concentration] = 0.570× Log 10 [dietary InAs exposure level per body weight] + 1.15 was obtained for whole data set. This equation would be valuable in converting urinary InAs concentration to daily InAs exposure, which will be important information in risk assessment.

RE: Request for Correction - SAB Workgroup Review of Draft IRIS Assessment for Inorganic Arsenic

EPA Pesticide Factsheets

Request from Lynn Bergeson for the correction of information in the draft EPA document Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System (IRIS).

Comparison of on-site field measured inorganic arsenic in rice with laboratory measurements using a field deployable method: Method validation.

PubMed

Mlangeni, Angstone Thembachako; Vecchi, Valeria; Norton, Gareth J; Raab, Andrea; Krupp, Eva M; Feldmann, Joerg

2018-10-15

A commercial arsenic field kit designed to measure inorganic arsenic (iAs) in water was modified into a field deployable method (FDM) to measure iAs in rice. While the method has been validated to give precise and accurate results in the laboratory, its on-site field performance has not been evaluated. This study was designed to test the method on-site in Malawi in order to evaluate its accuracy and precision in determination of iAs on-site by comparing with a validated reference method and giving original data on inorganic arsenic in Malawian rice and rice-based products. The method was validated by using the established laboratory-based HPLC-ICPMS. Statistical tests indicated there were no significant differences between on-site and laboratory iAs measurements determined using the FDM (p = 0.263, ά = 0.05) and between on-site measurements and measurements determined using HPLC-ICP-MS (p = 0.299, ά = 0.05). This method allows quick (within 1 h) and efficient screening of rice containing iAs concentrations on-site. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

Arsenic Release from Foodstuffs upon Food Preparation.

PubMed

Cheyns, Karlien; Waegeneers, Nadia; Van de Wiele, Tom; Ruttens, Ann

2017-03-22

In this study the concentration of total arsenic (As) and arsenic species (inorganic As, arsenobetaine, dimethylarsinate, and methylarsonate) was monitored in different foodstuffs (rice, vegetables, algae, fish, crustacean, molluscs) before and after preparation using common kitchen practices. By measuring the water content of the foodstuff and by reporting arsenic concentrations on a dry weight base, we were able to distinguish between As release effects due to food preparation and As decrease due to changes in moisture content upon food preparation. Arsenic species were released to the broth during boiling, steaming, frying, or soaking of the food. Concentrations declined with maxima of 57% for total arsenic, 65% for inorganic As, and 32% for arsenobetaine. On the basis of a combination of our own results and literature data, we conclude that the extent of this release of arsenic species is species specific, with inorganic arsenic species being released most easily, followed by the small organic As species and the large organic As species.

Arsenic Toxicity to Juvenile Fish: Effects of Exposure Route, Arsenic Speciation, and Fish Species

EPA Science Inventory

Arsenic toxicity to juvenile rainbow trout and fathead minnows was evaluated in 28-day tests using both dietborne and waterborne exposures, both inorganic and organic arsenic species, and both a live diet and an arsenic-spiked pellet diet. Effects of inorganic arsenic on rainbow...

Inorganic arsenic in Chinese food and its cancer risk.

PubMed

Li, Gang; Sun, Guo-Xin; Williams, Paul N; Nunes, Luis; Zhu, Yong-Guan

2011-10-01

Even moderate arsenic exposure may lead to health problems, and thus quantifying inorganic arsenic (iAs) exposure from food for different population groups in China is essential. By analyzing the data from the China National Nutrition and Health Survey (CNNHS) and collecting reported values of iAs in major food groups, we developed a framework of calculating average iAs daily intake for different regions of China. Based on this framework, cancer risks from iAs in food was deterministically and probabilistically quantified. The article presents estimates for health risk due to the ingestion of food products contaminated with arsenic. Both per individual and for total population estimates were obtained. For the total population, daily iAs intake is around 42 μg day(-1), and rice is the largest contributor of total iAs intake accounting for about 60%. Incremental lifetime cancer risk from food iAs intake is 106 per 100,000 for adult individuals and the median population cancer risk is 177 per 100,000 varying between regions. Population in the Southern region has a higher cancer risk than that in the Northern region and the total population. Sensitive analysis indicated that cancer slope factor, ingestion rates of rice, aquatic products and iAs concentration in rice were the most relevant variables in the model, as indicated by their higher contribution to variance of the incremental lifetime cancer risk. We conclude that rice may be the largest contributor of iAs through food route for the Chinese people. The population from the South has greater cancer risk than that from the North and the whole population. Copyright © 2011 Elsevier Ltd. All rights reserved.

Arsenic: bioaccessibility from seaweed and rice, dietary exposure calculations and risk assessment.

PubMed

Brandon, Esther F A; Janssen, Paul J C M; de Wit-Bos, Lianne

2014-01-01

Arsenic is a metalloid that occurs in food and the environment in different chemical forms. Inorganic arsenic is classified as a class I carcinogen. The inorganic arsenic intake from food and drinking water varies depending on the geographic arsenic background. Non-dietary exposure to arsenic is likely to be of minor importance for the general population within the European Union. In Europe, arsenic in drinking water is on average low, but food products (e.g. rice and seaweed) are imported from all over the world including from regions with naturally high arsenic levels. Therefore, specific populations living in Europe could also have a high exposure to inorganic arsenic due to their consumption pattern. Current risk assessment is based on exposure via drinking water. For a good estimation of the risks of arsenic in food, it is important to investigate if the bioavailability of inorganic arsenic from food is different from drinking water. The present study further explores the issue of European dietary exposure to inorganic arsenic via rice and seaweed and its associated health risks. The bioavailability of inorganic arsenic was measured in in vitro digestion experiments. The data indicate that the bioavailability of inorganic arsenic is similar for rice and seaweed compared with drinking water. The calculated dietary intake for specific European Union populations varied between 0.44 and 4.51 µg kg⁻¹ bw day⁻¹. The margins of exposure between the inorganic intake levels and the BMDL0.5 values as derived by JECFA are low. Decreasing the intake of inorganic arsenic via Hijiki seaweed could be achieved by setting legal limits similar to those set for rice by the Codex Alimentarius Commission in July 2014.

ELUCIDATING THE PATHWAY FOR ARSENIC METHYLATION

EPA Science Inventory

Enzymatically-catalyzed methylation of arsenic is part of a metabolic pathway that converts inorganic arsenic into methylated products. Hence, in humans chronically exposed to inorganic arsenic, methyl and dimethyl arsenic account for most of the arsenic that is excreted in the ...

Response surface methodology based on central composite design as a chemometric tool for optimization of dispersive-solidification liquid-liquid microextraction for speciation of inorganic arsenic in environmental water samples.

PubMed

Asadollahzadeh, Mehdi; Tavakoli, Hamed; Torab-Mostaedi, Meisam; Hosseini, Ghaffar; Hemmati, Alireza

2014-06-01

Dispersive-solidification liquid-liquid microextraction (DSLLME) coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of inorganic arsenic (III, V) in water samples. At pH=1, As(III) formed complex with ammonium pyrrolidine dithiocarbamate (APDC) and extracted into the fine droplets of 1-dodecanol (extraction solvent) which were dispersed with ethanol (disperser solvent) into the water sample solution. After extraction, the organic phase was separated by centrifugation, and was solidified by transferring into an ice bath. The solidified solvent was transferred to a conical vial and melted quickly at room temperature. As(III) was determined in the melted organic phase while As(V) remained in the aqueous layer. Total inorganic As was determined after the reduction of the pentavalent forms of arsenic with sodium thiosulphate and potassium iodide. As(V) was calculated by difference between the concentration of total inorganic As and As(III). The variable of interest in the DSLLME method, such as the volume of extraction solvent and disperser solvent, pH, concentration of APDC (chelating agent), extraction time and salt effect, was optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). In the optimum conditions, the proposed method has been successfully applied to the determination of inorganic arsenic in different environmental water samples and certified reference material (NIST RSM 1643e). 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)...

Simultaneously removal of inorganic arsenic species from stored rainwater in arsenic endemic area by leaves of Tecomella undulata: a multivariate study.

PubMed

Brahman, Kapil Dev; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Abro, Muhammad Ishaque; Arain, Sadaf Sadia; Ali, Jamshed; Khan, Sumaira

2016-08-01

In the present study, an indigenous biosorbent (leaves of Tecomella undulata) was used for the simultaneous removal of inorganic arsenic species (As(III) and As(V)) from the stored rainwater in Tharparkar, Pakistan. The Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of six factors/variables on the biosorption of inorganic arsenic species, simultaneously. Central composite design (CCD) was used to found the optimum values of significant factors for the removal of As(III) and As(V). Initial concentrations of both inorganic As species, pH, biosorbent dose, and contact time were selected as independent factors in CCD, while the adsorption capacity (q e) was considered as a response function. The separation of inorganic As species in water samples before and after biosorption was carried out by cloud point and solid-phase extraction methods. Theoretical values of pH, concentration of analytes, biosorbent dose, and contact time were calculated by quadratic equation for 100 % biosorption of both inorganic As species in aqueous media. Experimental data were modeled by Langmuir and Freundlich isotherms. Thermodynamic and kinetic study indicated that the biosorption of As(III) and As(V) was followed by pseudo second order. It was concluded that the indigenous biosorbent material efficiently and simultaneously removed both As species in the range of 70.8 to 98.5 % of total contents in studied ground water samples. Graphical abstract Optimizing the significant varable by central 2(3) + star orthogonal composite design.

Urinary arsenic profiles reveal exposures to inorganic arsenic from private drinking water supplies in Cornwall, UK.

PubMed

Middleton, D R S; Watts, M J; Hamilton, E M; Ander, E L; Close, R M; Exley, K S; Crabbe, H; Leonardi, G S; Fletcher, T; Polya, D A

2016-05-09

Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman's ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-As(IMM), of urinary inorganic As species, arsenite (As(III)) and arsenate (As(V)), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman's ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users.

Urinary arsenic profiles reveal exposures to inorganic arsenic from private drinking water supplies in Cornwall, UK

PubMed Central

Middleton, D. R. S.; Watts, M. J.; Hamilton, E. M.; Ander, E. L.; Close, R. M.; Exley, K. S.; Crabbe, H.; Leonardi, G. S.; Fletcher, T.; Polya, D. A.

2016-01-01

Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman’s ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-AsIMM, of urinary inorganic As species, arsenite (AsIII) and arsenate (AsV), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman’s ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users. PMID:27156998

Urinary arsenic profiles reveal exposures to inorganic arsenic from private drinking water supplies in Cornwall, UK

NASA Astrophysics Data System (ADS)

Middleton, D. R. S.; Watts, M. J.; Hamilton, E. M.; Ander, E. L.; Close, R. M.; Exley, K. S.; Crabbe, H.; Leonardi, G. S.; Fletcher, T.; Polya, D. A.

2016-05-01

Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman’s ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-AsIMM, of urinary inorganic As species, arsenite (AsIII) and arsenate (AsV), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman’s ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users.

SPECIATION AND PRESERVATION OF INORGANIC ARSENIC IN DRINKING WATER SUPPLIES WITH IC-ICP-MS

EPA Science Inventory

The speciation of inorganic arsenic in drinking water supplies is an essential part of devising an appropriate treatment process. Arsenate, because of its anion characteristics at drinking water pHs, is effectively removed by anion exchange treatment while arsenite remains in the...

A Systematic Review and Meta-Regression Analysis of Lung Cancer Risk and Inorganic Arsenic in Drinking Water.

PubMed

Lamm, Steven H; Ferdosi, Hamid; Dissen, Elisabeth K; Li, Ji; Ahn, Jaeil

2015-12-07

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1-1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100-150 µg/L arsenic.

A Systematic Review and Meta-Regression Analysis of Lung Cancer Risk and Inorganic Arsenic in Drinking Water

PubMed Central

Lamm, Steven H.; Ferdosi, Hamid; Dissen, Elisabeth K.; Li, Ji; Ahn, Jaeil

2015-01-01

High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1–1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100–150 µg/L arsenic. PMID:26690190

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.

Fact Sheet on Arsenic

EPA Pesticide Factsheets

Arsenic is a naturally occurring element that is found in combination with either inorganic or organic substances to form many different compounds. Inorganic arsenic compounds are found in soils, sediments, and groundwater.

Chronic inorganic arsenic exposure in vitro induces a cancer cell phenotype in human peripheral lung epithelial cells

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

Person, Rachel J.; Olive Ngalame, Ntube N.; Makia, Ngome L.

Inorganic arsenic is a human lung carcinogen. We studied the ability of chronic inorganic arsenic (2 μM; as sodium arsenite) exposure to induce a cancer phenotype in the immortalized, non-tumorigenic human lung peripheral epithelial cell line, HPL-1D. After 38 weeks of continuous arsenic exposure, secreted matrix metalloproteinase-2 (MMP2) activity increased to over 200% of control, levels linked to arsenic-induced cancer phenotypes in other cell lines. The invasive capacity of these chronic arsenic-treated lung epithelial (CATLE) cells increased to 320% of control and colony formation increased to 280% of control. CATLE cells showed enhanced proliferation in serum-free media indicative of autonomousmore » growth. Compared to control cells, CATLE cells showed reduced protein expression of the tumor suppressor gene PTEN (decreased to 26% of control) and the putative tumor suppressor gene SLC38A3 (14% of control). Morphological evidence of epithelial-to-mesenchymal transition (EMT) occurred in CATLE cells together with appropriate changes in expression of the EMT markers vimentin (VIM; increased to 300% of control) and e-cadherin (CDH1; decreased to 16% of control). EMT is common in carcinogenic transformation of epithelial cells. CATLE cells showed increased KRAS (291%), ERK1/2 (274%), phosphorylated ERK (p-ERK; 152%), and phosphorylated AKT1 (p-AKT1; 170%) protein expression. Increased transcript expression of metallothioneins, MT1A and MT2A and the stress response genes HMOX1 (690%) and HIF1A (247%) occurred in CATLE cells possibly in adaptation to chronic arsenic exposure. Thus, arsenic induced multiple cancer cell characteristics in human peripheral lung epithelial cells. This model may be useful to assess mechanisms of arsenic-induced lung cancer. - Highlights: • Chronic arsenic exposure transforms a human peripheral lung epithelia cell line. • Cells acquire characteristics in common with human lung adenocarcinoma cells. • These transformed cells

Arsenic Exposure and Cancer Mortality in a US-based Prospective Cohort: the Strong Heart Study

PubMed Central

García-Esquinas, Esther; Pollán, Marina; Umans, Jason G.; Francesconi, Kevin A.; Goessler, Walter; Guallar, Eliseo; Howard, Barbara; Farley, John; Yeh, Jeunliang; Best, Lyle G.; Navas-Acien, Ana

2013-01-01

Background Inorganic arsenic, a carcinogen at high exposure levels, is a major global health problem. Prospective studies on carcinogenic effects at low-moderate arsenic levels are lacking. Methods We evaluated the association between baseline arsenic exposure and cancer mortality in 3,932 American Indians 45–74 years from Arizona, Oklahoma and North/South Dakota who participated in the Strong Heart Study in 1989–1991 and were followed through 2008. We estimated inorganic arsenic exposure as the sum of inorganic and methylated species in urine. Cancer deaths (386 overall, 78 lung, 34 liver, 18 prostate, 26 kidney, 24 esophagus/stomach, 25 pancreas, 32 colon/rectal, 26 breast, 40 lymphatic/hematopoietic) were assessed by mortality surveillance reviews. We hypothesized an association with lung, liver, prostate and kidney cancer. Results Median (interquartile range) urine concentration for inorganic plus methylated arsenic species was 9.7 (5.8–15.6) μg/g creatinine. The adjusted hazard ratios (95% CI) comparing the 80th versus 20th percentiles of arsenic were 1.14 (0.92–1.41) for overall cancer, 1.56 (1.02–2.39) for lung cancer, 1.34 (0.66, 2.72) for liver cancer, 3.30 (1.28–8.48) for prostate cancer, and 0.44 (0.14, 1.14) for kidney cancer. The corresponding hazard ratios were 2.46 (1.09–5.58) for pancreatic cancer, and 0.46 (0.22–0.96) for lymphatic and hematopoietic cancers. Arsenic was not associated with cancers of the esophagus and stomach, colon and rectum, and breast. Conclusions Low to moderate exposure to inorganic arsenic was prospectively associated with increased mortality for cancers of the lung, prostate and pancreas. Impact These findings support the role of low-moderate arsenic exposure in lung, prostate and pancreas cancer development and can inform arsenic risk assessment. PMID:23800676

DIFFERENTIAL ACTIVATION OF AP-1 IN HUMAN BLADDER EPITHELIAL CELLS BY INORGANIC AND METHYLATED ARSENICALS

EPA Science Inventory

Differential Activation of AP-1 in Human Bladder Epithelial Cells by Inorganic and Methylated Arsenicals

Zuzana Drobna, Ilona Jaspers, David J. Thomas, and Miroslav Styblo

ABSTRACT

Epidemiological studies have linked chronic ingestion of drinking water contai...

Inorganic arsenic removal in rice bran by percolating cooking water.

PubMed

Signes-Pastor, Antonio J; Carey, Manus; Meharg, Andrew A

2017-11-01

Rice bran, a by-product of milling rice, is highly nutritious but contains very high levels of the non-threshold carcinogen inorganic arsenic (i-As), at concentrations around 1mg/kg. This i-As content needs to be reduced to make rice bran a useful food ingredient. Evaluated here is a novel approach to minimizing rice bran i-As content which is also suitable for its stabilization namely, cooking bran in percolating arsenic-free boiling water. Up to 96% of i-As removal was observed for a range of rice bran products, with i-As removal related to the volume of cooking water used. This process reduced the copper, potassium, and phosphorus content, but had little effect on other trace- and macro-nutrient elements in the rice bran. There was little change in organic composition, as assayed by NIR, except for a decrease in the soluble sugar and an increase, due to biomass loss, in dietary fiber. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chronic arsenic exposure increases TGFalpha concentration in bladder urothelial cells of Mexican populations environmentally exposed to inorganic arsenic

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

Valenzuela, Olga L.; Germolec, Dori R.; Borja-Aburto, Victor H.

Inorganic arsenic (iAs) is a well-established carcinogen and human exposure has been associated with a variety of cancers including those of skin, lung, and bladder. High expression of transforming growth factor alpha (TGF-{alpha}) has associated with local relapses in early stages of urinary bladder cancer. iAs exposures are at least in part determined by the rate of formation and composition of iAs metabolites (MAs{sup III}, MAs{sup V}, DMAs{sup III}, DMAs{sup V}). This study examines the relationship between TGF-{alpha} concentration in exfoliated bladder urothelial cells (BUC) separated from urine and urinary arsenic species in 72 resident women (18-51 years old) frommore » areas exposed to different concentrations of iAs in drinking water (2-378 ppb) in central Mexico. Urinary arsenic species, including trivalent methylated metabolites were measured by hydride generation atomic absorption spectrometry method. The concentration of TGF-{alpha} in BUC was measured using an ELISA assay. Results show a statistically significant positive correlation between TGF-{alpha} concentration in BUC and each of the six arsenic species present in urine. The multivariate linear regression analyses show that the increment of TGF-{alpha} levels in BUC was importantly associated with the presence of arsenic species after adjusting by age, and presence of urinary infection. People from areas with high arsenic exposure had a significantly higher TGF-{alpha} concentration in BUC than people from areas of low arsenic exposure (128.8 vs. 64.4 pg/mg protein; p < 0.05). Notably, exfoliated cells isolated from individuals with skin lesions contained significantly greater amount of TGF-{alpha} than cells from individuals without skin lesions: 157.7 vs. 64.9 pg/mg protein (p = 0.003). These results suggest that TGF-{alpha} in exfoliated BUC may serve as a susceptibility marker of adverse health effects on epithelial tissue in arsenic-endemic areas.« less

Substantial contribution of biomethylation to aquifer arsenic cycling

USGS Publications Warehouse

Maguffin, Scott C.; Kirk, Matthew F.; Daigle, Ashley R.; Hinkle, Stephen R.; Jin, Qusheng

2015-01-01

Microbes play a prominent role in transforming arsenic to and from immobile forms in aquifers1. Much of this cycling involves inorganic forms of arsenic2, but microbes can also generate organic forms through methylation3, although this process is often considered insignificant in aquifers4, 5, 6, 7. Here we identify the presence of dimethylarsinate and other methylated arsenic species in an aquifer hosted in volcaniclastic sedimentary rocks. We find that dimethylarsinate is widespread in the aquifer and its concentration correlates strongly with arsenite concentration. We use laboratory incubation experiments and an aquifer injection test to show that aquifer microbes can produce dimethylarsinate at rates of about 0.1% of total dissolved arsenic per day, comparable to rates of dimethylarsinate production in surface environments. Based on these results, we estimate that globally, biomethylation in aquifers has the potential to transform 100 tons of inorganic arsenic to methylated arsenic species per year, compared with the 420–1,250 tons of inorganic arsenic that undergoes biomethylation in soils8. We therefore conclude that biomethylation could contribute significantly to aquifer arsenic cycling. Because biomethylation yields arsine and methylarsines, which are more volatile and prone to diffusion than other arsenic species, we further suggest that biomethylation may serve as a link between surface and subsurface arsenic cycling.

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.

Arsenic concentrations in Baltic Sea sediments close to chemical munitions dumpsites

NASA Astrophysics Data System (ADS)

Bełdowski, Jacek; Szubska, Marta; Emelyanov, Emelyan; Garnaga, Galina; Drzewińska, Anna; Bełdowska, Magdalena; Vanninen, Paula; Östin, Anders; Fabisiak, Jacek

2016-06-01

In addition to natural sources and land-originated pollution, the Baltic Sea has another anthropogenic source of arsenic in bottom sediments-arsenic-based Chemical Warfare Agents (CWA). To examine the potential usage of arsenic contents results for monitoring the leakage from chemical weapons, sediment samples were collected from officially reported and potential chemical weapon dumpsites located in the Baltic Sea, and total and inorganic arsenic concentrations were analyzed. Results showed an elevated arsenic content in dumpsite areas compared to reference areas. Correlations of arsenic with other metals and organic matter were studied to elucidate any unusual behavior of arsenic in the dumpsites. In the area of the Bornholm Deep, such behavior was observed for inorganic arsenic. It appears that in close vicinity of dumped munitions, the inorganic arsenic concentration of sediments is not correlated with either organic matter content or authigenic minerals formation, as is commonly observed elsewhere. Investigations on CWA concentrations, performed within the CHEMSEA (Chemical Munition Search and Assesment) project, allowed us to compare the results of arsenic concentrations with the occurrence of arsenic-containing CWA.

Arsenic Speciation in Plankton Organisms from Contaminated Lakes: Transformations at the Base of the Freshwater Food Chain

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

Caumette, Guilhem; Koch, Iris; Estrada, Esteban

2012-02-06

The two complementary techniques high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and X-ray absorption near edge structure (XANES) analysis were used to assess arsenic speciation in freshwater phytoplankton and zooplankton collected from arsenic-contaminated lakes in Yellowknife (Northwest Territories, Canada). Arsenic concentrations in lake water ranged from 7 {micro}g L{sup -1} in a noncontaminated lake to 250 {micro}g L{sup -1} in mine-contaminated lakes, which resulted in arsenic concentrations ranging from 7 to 340 mg kg{sup -1} d.w. in zooplankton organisms (Cyclops sp.) and from 154 to 894 mg kg{sup -1} d.w. in phytoplankton. The main arsenic compounds identified by HPLC-ICP-MSmore » in all plankton were inorganic arsenic (from 38% to 98% of total arsenic). No other arsenic compounds were found in phytoplankton, but zooplankton organisms showed the presence of organoarsenic compounds, the most common being the sulfate arsenosugar, up to 47% of total arsenic, with traces of phosphate sugar, glycerol sugar, methylarsonate (MMA), and dimethylarsinate (DMA). In the uncontaminated Grace Lake, zooplankton also contained arsenobetaine (AB). XANES characterization of arsenic in the whole plankton samples showed AsV-O as the only arsenic compound in phytoplankton, and AsIII-S and AsV-O compounds as the two major inorganic arsenic species in zooplankton. The proportion of organoarsenicals and inorganic arsenic in zooplankton depends upon the arsenic concentration in lakes and shows the impact of arsenic contamination: zooplankton from uncontaminated lake has higher proportions of organoarsenic compounds and contains arsenobetaine, while zooplankton from contaminated area contains mostly inorganic arsenic.« less

Co-exposure to methylmercury and inorganic arsenic in baby rice cereals and rice-containing teething biscuits.

PubMed

Rothenberg, Sarah E; Jackson, Brian P; Carly McCalla, G; Donohue, Alexis; Emmons, Alison M

2017-11-01

Rice is an important dietary source for methylmercury (MeHg), a potent neurotoxin, and inorganic arsenic (As), a human carcinogen. Rice baby cereals are a dietary source of inorganic As; however, less is known concerning MeHg concentrations in rice baby cereals and rice teething biscuits. MeHg concentrations were measured in 36 rice baby cereals, eight rice teething biscuits, and four baby cereals manufactured with oats/wheat (n = 48 total). Arsenic (As) species, including inorganic As, were determined in rice baby cereals and rice teething biscuits (n = 44/48), while total As was determined in all products (n = 48). Rice baby cereals and rice teething biscuits were on average 61 and 92 times higher in MeHg, respectively, and 9.4 and 4.7 times higher in total As, respectively, compared to wheat/oat baby cereals. For a 15-g serving of rice baby cereal, average MeHg intake was 0.0092μgday -1 (range: 0.0013-0.034μgday -1 ), while average inorganic As intake was 1.3μgday -1 (range: 0.37-2.3μgday -1 ). Inorganic As concentrations in two brands of rice baby cereal (n = 12/36 boxes of rice cereal) exceeded 100ng/g, the proposed action level from the U.S. Food and Drug Administration. Log 10 MeHg and inorganic As concentrations in rice baby cereals were strongly, positively correlated (Pearson's rho = 0.60, p < 0.001, n = 36). Rice-containing baby cereals and teething biscuits were a dietary source of both MeHg and inorganic As. Studies concerning the cumulative impacts of MeHg and inorganic As on offspring development are warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Arsenic and diabetes: current perspectives.

PubMed

Huang, Chun Fa; Chen, Ya Wen; Yang, Ching Yao; Tsai, Keh Sung; Yang, Rong Sen; Liu, Shing Hwa

2011-09-01

Arsenic is a naturally occurring toxic metalloid of global concern. Many studies have indicated a dose-response relationship between accumulative arsenic exposure and the prevalence of diabetes mellitus (DM) in arseniasis-endemic areas in Taiwan and Bangladesh, where arsenic exposure occurs through drinking water. Epidemiological researches have suggested that the characteristics of arsenic-induced DM observed in arseniasis-endemic areas in Taiwan and Mexico are similar to those of non-insulin-dependent DM (Type 2 DM). These studies analyzed the association between high and chronic exposure to inorganic arsenic in drinking water and the development of DM, but the effect of exposure to low to moderate levels of inorganic arsenic on the risk of DM is unclear. Navas-Acien et al. recently proposed that a positive association existed between total urine arsenic and the prevalence of Type 2 DM in people exposed to low to moderate levels of arsenic. However, the diabetogenic role played by arsenic is still debated upon. An increase in the prevalence of DM has been observed among residents of highly arsenic-contaminated areas, whereas the findings from community-based and occupational studies in low-arsenic-exposure areas have been inconsistent. Recently, a population-based cross-sectional study showed that the current findings did not support an association between arsenic exposure from drinking water at levels less than 300 μg/L and a significantly increased risk of DM. Moreover, although the precise mechanisms for the arsenic-induced diabetogenic effect are still largely undefined, recent in vitro experimental studies indicated that inorganic arsenic or its metabolites impair insulin-dependent glucose uptake or glucose-stimulated insulin secretion. Nevertheless, the dose, the form of arsenic used, and the experimental duration in the in vivo studies varied greatly, leading to conflicting results and ambiguous interpretation of these data with respect to human exposure

Measurements of Arsenic in the Urine and Nails of Individuals Exposed to Low Concentrations of Arsenic in Drinking Water From Private Wells in a Rural Region of Québec, Canada.

PubMed

Gagnon, Fabien; Lampron-Goulet, Eric; Normandin, Louise; Langlois, Marie-France

2016-01-01

Chronic exposure to inorganic arsenic leads to an increased risk of cancer. A biological measurement was conducted in 153 private well owners and their families consuming water contaminated by inorganic arsenic at concentrations that straddle 10 μg/L. The relationship between the external dose indicators (concentration of inorganic arsenic in wells and daily well water inorganic arsenic intake) and the internal doses (urinary arsenic--sum of As(III), DMA, and MMA, adjusted for creatinine--and total arsenic in toenails) was evaluated using multiple linear regressions, controlling for age, gender, dietary sources of arsenic, and number of cigarettes smoked. It showed that urinary arsenic was associated with concentration of inorganic arsenic in wells (p < .001) and daily well water inorganic arsenic intake (p < .001) in adults, and with daily well water inorganic arsenic intake (p = .017) and rice consumption (p = .022) in children (n = 43). The authors' study reinforces the drinking-water quality guidelines for inorganic arsenic.

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

Correlation of Breastmilk Arsenic With Maternal, Infant Urinary Arsenic and Drinking Water Arsenic in an Arsenic Affected Area of Bangladesh

NASA Astrophysics Data System (ADS)

Alauddin, M.; Islam, M. R.; Milton, A. H.; Alauddin, S. T.; Mouly, T.; Behri, E.; Ayesha, A.; Akter, S.; Islam, M. M.

2016-12-01

About 97% of population in Bangladesh depend on groundwater as the principle source of drinking water and this water is highly contaminated with inorganic arsenic. Consumption of arsenic contaminated drinking water by pregnant women raises the prospect of early life exposure to inorganic arsenic for newborn which may be lead to adverse health effect in later life. This work was carried out in parts of Gopalganj district in Bangladesh, a region affected by arsenic contamination in groundwater. The objective of the work was to assess potential early life exposure to arsenic for infants through breastfeeding by mothers who were drinking water with arsenic levels ranging from 100 to 300 µg/l. A cohort of 30 mother-baby pairs were selected for the current study. Breastmilk samples from mothers, urine samples from each pair of subjects at 1, 6 and 9 month age of infant were collected and total arsenic were determined in these samples. In addition speciation of urinary arsenic and metabolites were carried out in 12 mother-baby pairs. Median level for breastmilk arsenic were 0.50 µg/l. Urinary arsenic of infants did not correlate with breastmilk arsenic with progressing age of infants. Maternal and infant urinary total arsenic at 1 month age of infant showed some positive correlation (r = 0.39). In infant urine major metabolite were dimethyl arsenic acid (DMA) (approximately 70%) indicating good methylating capacity for infants at 1 and 6 months of age. In conclusion, infants were not exposed to arsenic through breastfeeding even though mothers were exposed to significant levels of arsenic through drinking water.

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.

Carotid Intima-Media Thickness and Plasma Asymmetric Dimethylarginine in Mexican Children Exposed to Inorganic Arsenic

PubMed Central

Osorio-Yáñez, Citlalli; Ayllon-Vergara, Julio C.; Aguilar-Madrid, Guadalupe; Arreola-Mendoza, Laura; Hernández-Castellanos, Erika; Barrera-Hernández, Angel; De Vizcaya-Ruiz, Andrea

2013-01-01

Background: Arsenic exposure is a risk factor for atherosclerosis in adults, but there is little information on arsenic and early risk biomarkers for atherosclerosis in children. Carotid intima-media thickness (cIMT) is an indicator of subclinical atherosclerotic burden that has been associated with plasma asymmetric dimethylarginine (ADMA), a predictor of cardiovascular disease risk. Objectives: The aim of this study was to investigate associations of arsenic exposure with cIMT, ADMA, and endothelial adhesion molecules [soluble intercellular cell adhesion molecule-1 (sICAM-1); soluble vascular cell adhesion molecule-1 (sVCAM-1)] in children who had been exposed to environmental inorganic arsenic (iAs). Methods: We conducted a cross-sectional study in 199 children 3–14 years of age who were residents of Zimapan, México. We evaluated cIMT using ultrasonography, and plasma lipid profiles by standard methods. We analyzed ADMA, sICAM-1, and sVCAM-1 by ELISA, and measured the concentrations of total speciated arsenic (tAs) in urine using hydride generation cryotrapping atomic absorption spectrometry. Results: In the multiple linear regression model for cIMT, tAs categories were positively associated with cIMT increase. The estimated cIMT diameter was greater in 35- to 70-ng/mL and > 70-ng/mL groups (0.035 mm and 0.058 mm per 1-ng/mL increase in urinary tAs, respectively), compared with the < 35-ng/mL group. In addition to tAs level, plasma ADMA was a significant predictor of cIMT. In the adjusted regression model, cIMT, percent iAs, and plasma sVCAM-1 were significant predictors of ADMA levels (e.g., 0.419-μmol/L increase in ADMA per 1-mm increase in cIMT). Conclusions: Arsenic exposure and plasma ADMA levels were positively associated with cIMT in a population of Mexican children with environmental arsenic exposure through drinking water. Citation: Osorio-Yáñez C, Ayllon-Vergara JC, Aguilar-Madrid G, Arreola-Mendoza L, Hernández-Castellanos E, Barrera

A need for determination of arsenic species at low levels in cereal-based food and infant cereals. Validation of a method by IC-ICPMS.

PubMed

Llorente-Mirandes, Toni; Calderón, Josep; Centrich, Francesc; Rubio, Roser; López-Sánchez, José Fermín

2014-03-15

The present study arose from the need to determine inorganic arsenic (iAs) at low levels in cereal-based food. Validated methods with a low limit of detection (LOD) are required to analyse these kinds of food. An analytical method for the determination of iAs, methylarsonic acid (MA) and dimethylarsinic acid (DMA) in cereal-based food and infant cereals is reported. The method was optimised and validated to achieve low LODs. Ion chromatography-inductively coupled plasma mass spectrometry (IC-ICPMS) was used for arsenic speciation. The main quality parameters were established. To expand the applicability of the method, different cereal products were analysed: bread, biscuits, breakfast cereals, wheat flour, corn snacks, pasta and infant cereals. The total and inorganic arsenic content of 29 cereal-based food samples ranged between 3.7-35.6 and 3.1-26.0 μg As kg(-1), respectively. The present method could be considered a valuable tool for assessing inorganic arsenic contents in cereal-based foods. Copyright © 2013 Elsevier Ltd. All rights reserved.

Use of mode of action data to inform a dose-response assessment for bladder cancer following exposure to inorganic arsenic.

PubMed

Gentry, P R; Yager, J W; Clewell, R A; Clewell, H J

2014-10-01

In the recent National Research Council report on conducting a dose-response assessment for inorganic arsenic, the committee remarked that mode of action data should be used, to the extent possible, to extrapolate below the observed range for epidemiological studies to inform the shape of the dose-response curve. Recent in vitro mode of action studies focused on understanding the development of bladder cancer following exposure to inorganic arsenic provide data to inform the dose-response curve. These in vitro data, combined with results of bladder cancer epidemiology studies, inform the dose-response curve in the low-dose region, and include values for both pharmacokinetic and pharmacodynamic variability. Integration of these data provides evidence of a range of concentrations of arsenic for which no effect on the bladder would be expected. Specifically, integration of these results suggest that arsenic exposures in the range of 7-43 ppb in drinking water are exceedingly unlikely to elicit changes leading to key events in the development of cancer or noncancer effects in bladder tissue. These findings are consistent with the lack of evidence for bladder cancer following chronic ingestion of arsenic water concentrations <100 ppb in epidemiological studies. Copyright © 2014 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.

Inter-laboratory validation of an inexpensive streamlined method to measure inorganic arsenic in rice grain

USDA-ARS?s Scientific Manuscript database

With the establishment by CODEX of a 200 ng/g limit of inorganic arsenic (iAs) in polished rice grain, more analyses of iAs will be necessary to ensure compliance in regulatory and trade applications, to assess quality control in commercial rice production, and to conduct research involving iAs in r...

DIETARY ARSENIC EXPOSURE ASSESSMENT USING ENZYMATIC BASED EXTRACTION CONDITIONS AND DETECTION OF URINARY THIO-ARSENICALS AS METABOLITES OF EXPOSURE - MCEARD2

EPA Science Inventory

Inorganic arsenic is classified as a carcinogen and has been linked to lung and bladder cancer as well as other non-cancerous health effects. Because of these health effects the U.S. EPA has set a Maximum Contaminant Level (MCL) at 10ppb based on a linear extrapolation of risk an...

Arsenic Metabolism and Distribution in Developing Organisms

EPA Science Inventory

A growing body of evidence suggests that exposure to inorganic arsenic during early life has long term adverse effects. The extent of exposure to inorganic arsenic and its methylated metabolites in utero is determined not only by the rates of formation and transfer of arsenicals...

Inorganic arsenic exposure increased expression of Fas and Bax gene in vivo and vitro.

PubMed

He, Yuefeng; Zhang, Ruobing; Xiaoxiao, Song; Li, Shang; Xinan, Wu; Huang, Dahai

2018-06-01

Accumulating evidences have shown that apoptosis plays an important role in mediating the therapeutic effects and toxicity of arsenic. Fas and Bax genes are critical regulatory genes for apoptosis. In this study, we investigated the association between levels of Fas and Bax expression and the three arsenic species (inorganic arsenic (iAs), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)) in vivo and vitro. Three arsenic species in urine were measured and levels of Fas and Bax expression were examined by the quantitative real-time PCR (qPCR) for all subjects. We found that Fas and Bax mRNA expression in the exposed group were significantly higher than that in the control group. The levels of gene expression were positively correlated with the concentrations of urinary iAs, MMA and DMA in all subjects. Sodium arsenite induced Fas and Bax mRNA expression, then MMA and DMA did not induce mRNA expression in MDA-MB-231 and XWLC-05 cells. The findings of the present study indicated that iAs, MMA, and DMA had different effects on expression of Bax and Fas gene. Copyright © 2017. Published by Elsevier B.V.

Arsenic (+3 oxidation state) methyltransferase and the methylation of arsenicals in the invertebrate chordate Ciona intestinalis

EPA Science Inventory

The biotransformation of inorganic arsenic (iAs) involves methylation by an arsenic (+3 oxidation state) methyltransferase (AS3MT), yielding methyl arsenic (MA), dimethyl arsenic (DMA), and trimethylarsenic (TMA). To identify molecular mechanisms that coordinate arsenic biotra...

Titanium dioxide solid phase for inorganic species adsorption and determination: the case of arsenic.

PubMed

Vera, R; Fontàs, C; Anticó, E

2017-04-01

We have evaluated a new titanium dioxide (Adsorbsia As600) for the adsorption of both inorganic As (V) and As (III) species. In order to characterize the sorbent, batch experiments were undertaken to determine the capacities of As (III) and As (V) at pH 7.3, which were found to be 0.21 and 0.14 mmol g -1 , respectively. Elution of adsorbed species was only possible using basic solutions, and arsenic desorbed under batch conditions was 50 % when 60 mg of loaded titanium dioxide was treated with 0.5 M NaOH solution. Moreover, its use as a sorbent for solid-phase extraction and preconcentration of arsenic species from well waters has been investigated, without any previous pretreatment of the sample. Solid-phase extraction was implemented by packing several minicolumns with Adsorbsia As600. The method has been validated showing good accuracy and precision. Acceptable recoveries were obtained when spiked waters at 100-200 μg L -1 were measured. The presence of major anions commonly found in waters did not affect arsenic adsoption, and only silicate at 100 mg L -1 level severely competed with arsenic species to bind to the material. Finally, the measured concentrations in water samples containing arsenic from the Pyrinees (Catalonia, Spain) showed good agreement with the ICP-MS results.

75 FR 7477 - Draft Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

... Environmental Assessment (NCEA) within the EPA's Office of Research and Development (ORD). The Toxicological Review of Inorganic Arsenic was submitted to the EPA's Science Advisory Board (SAB) for external peer... IRIS IRIS is a human health assessment program that evaluates quantitative and qualitative risk...

RE: Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System -- Comments Submitted for Review by the SAB Workgroup

EPA Pesticide Factsheets

Submission of comments by the Organic Arsenical Products Task Force on the draft document Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System (IRIS).

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

THE CELLUAR METABOLISM OF ARSENIC

EPA Science Inventory

Because the methylation of arsenic produces intermediates and terminal products that exceed inorganic arsenic in potency as enzyme inhibitors, cytotoxins, and genotoxins, the methylation of arsenic is properly regarded as an activation process. The methylation of arsenic is an e...

Arsenic (+3 oxidation state) methyltransferase and the methylation of arsenicals in the invertebrate chordate Ciona intestinalis

EPA Science Inventory

Biotransformation of inorganic arsenic (iAs) involves methylation catalyzed by arsenic (+3 oxidation state) methyltransferase (As3mt), yielding mono- , di- , and trimethylated arsenicals. To investigate the evolution of molecular mechanisms that mediate arsenic biotransformation,...

Association between multi-level inorganic arsenic exposure from drinking water and skin lesions in China.

PubMed

Guo, Xiaojuan; Fujino, Yoshihisa; Ye, Xiaolei; Liu, Jun; Yoshimura, Takesumi

2006-09-01

Arsenic is one of the most important toxicants in the environment. In Inner Mongolia of China, 300,000 residents are believed to be drinking water containing >50 microg/liter. Skin lesions have been known as the most common consequences resulting from chronic exposure to arsenic. To clarify the prevalence of arsenic-induced skin lesions, it is important to assess the impact of this problem among the target population, and to make future planning. We evaluated the association between multi-levels inorganic arsenic exposure from drinking water and skin lesions in an arsenic-affected area in Inner Mongolia, China. One hundred nine and 32 subjects in high (>50 microg/liter) and low (<50 microg/liter) arsenic-affected villages were recruited and had the detailed physical examination with special emphasis on arsenic-related skin lesions. Arsenic exposure was measured for each participant with respect to iAs concentration of primary well and the duration using the well. Arsenic-induced skin lesions including keratosis, pigmentation, and/or depigmentation were diagnosed in 56 and 3 subjects in the two villages, respectively. Logistic regression was conducted to calculate odd ratios of skin lesions associated with arsenic exposure with adjustments for sex, age group, smoking and duration of exposure. A consistent dose-response relationship between arsenic exposure level and skin lesion risk was observed. Compared to those with iAs concentration <50 microg/liter, the adjusted odds ratios of skin lesions for the subjects with 51-99, 100-149 and >150 microg/liter were 33.3% (OR =15.50, 95% CI: 1.53-248.70), 46.7% (OR =16.10, 95% CI: 3.73-69.63) and 55.7% (OR= 25.70, 95% CI: 6.43-102.87), respectively. Duration of using well was not associated with increased risk of skin lesions in this population; (OR =1.68, 95% CI: 0.40-6.91 for 6-15 years, OR = 2.30, 95% CI: 0.58-9.14 for over 15 years) compared with the duration of less than 5 years.

Estimating Inorganic Arsenic Exposure from U.S. Rice and Total Water Intakes.

PubMed

Mantha, Madhavi; Yeary, Edward; Trent, John; Creed, Patricia A; Kubachka, Kevin; Hanley, Traci; Shockey, Nohora; Heitkemper, Douglas; Caruso, Joseph; Xue, Jianping; Rice, Glenn; Wymer, Larry; Creed, John T

2017-05-30

Among nonoccupationally exposed U.S. residents, drinking water and diet are considered primary exposure pathways for inorganic arsenic (iAs). In drinking water, iAs is the primary form of arsenic (As), while dietary As speciation techniques are used to differentiate iAs from less toxic arsenicals in food matrices. Our goal was to estimate the distribution of iAs exposure rates from drinking water intakes and rice consumption in the U.S. population and ethnic- and age-based subpopulations. The distribution of iAs in drinking water was estimated by population, weighting the iAs concentrations for each drinking water utility in the Second Six-Year Review data set. To estimate the distribution of iAs concentrations in rice ingested by U.S. consumers, 54 grain-specific, production-weighted composites of rice obtained from U.S. mills were extracted and speciated using both a quantitative dilute nitric acid extraction and speciation (DNAS) and an in vitro gastrointestinal assay to provide an upper bound and bioaccessible estimates, respectively. Daily drinking water intake and rice consumption rate distributions were developed using data from the What We Eat in America (WWEIA) study. Using these data sets, the Stochastic Human Exposure and Dose Simulation (SHEDS) model estimated mean iAs exposures from drinking water and rice were 4.2 μg/day and 1.4 μg/day, respectively, for the entire U.S. population. The Tribal, Asian, and Pacific population exhibited the highest mean daily exposure of iAs from cooked rice (2.8 μg/day); the mean exposure rate for children between ages 1 and 2 years in this population is 0.104 μg/kg body weight (BW)/day. An average consumer drinking 1.5 L of water daily that contains between 2 and 3 ng iAs/mL is exposed to approximately the same amount of iAs as a mean Tribal, Asian, and Pacific consumer is exposed to from rice. https://doi.org/10.1289/EHP418. Among nonoccupationally exposed U.S. residents, drinking water and diet are considered

Assessing and managing the health risk due to ingestion of inorganic arsenic from fish and shellfish farmed in blackfoot disease areas for general Taiwanese.

PubMed

Liang, Ching-Ping; Liu, Chen-Wuing; Jang, Cheng-Shin; Wang, Sheng-Wei; Lee, Jin-Jing

2011-02-15

This paper assesses health risks due to the ingestion of inorganic arsenic from fish and shellfish farmed in blackfoot disease areas by general public in Taiwan. The provisional tolerable weekly intake of arsenic set by FAO/WHO and the target cancer risk assessment model proposed by USEPA were integrated to evaluate the acceptable consumption rate. Five aquacultural species, tilapia (Oreochromis mossambicus), milkfish (Chanos chanos), mullet (Mugil cephalus), clam (Meretrix lusoria) and oyster (Crassostrea gigas) were included. Monte Carlo analysis was used to propagate the parameter uncertainty and to probabilistically assess the health risk associated with the daily intake of inorganic As from farmed fish and shellfish. The integrated risk-based analysis indicates that the associated 50th and 95th percentile health risk are 2.06×10(-5) and 8.77×10(-5), respectively. Moreover, the acceptable intakes of inorganic As are defined and illustrated by a two dimensional graphical model. According to the relationship between C(inorg) and IR(f) derived from this study, two risk-based curves are constructed. An acceptable risk zone is determined (risk ranging from 1×10(-5) to 6.07×10(-5)) which is recommended for acceptable consumption rates of fish and shellfish. To manage the health risk due to the ingestion of inorganic As from fish and shellfish in BFD areas, a risk-based management scheme is derived which provide a convenient way for general public to self-determine the acceptable seafood consumption rate. Copyright © 2010 Elsevier B.V. All rights reserved.

Systematic review of differential inorganic arsenic exposure in minority, low-income, and indigenous populations in the United States

EPA Science Inventory

Inorganic arsenic (iAs) is carcinogenic in humans and also associated with cardiovascular, respiratory, and skin diseases. Natural and anthropogenic sources contribute to low concentrations of iAs in water, food, soil, and air. Minority and low income populations are often at hig...

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.

Evaluation of epigenetic alterations (mir-126 and mir-155 expression levels) in Mexican children exposed to inorganic arsenic via drinking water.

PubMed

Pérez-Vázquez, Mónica S; Ochoa-Martínez, Ángeles C; RuÍz-Vera, Tania; Araiza-Gamboa, Yesenia; Pérez-Maldonado, Iván N

2017-12-01

Recently, a great number of epidemiological studies have shown evidence that exposure to inorganic arsenic could have harmful effects on the cardiovascular system of humans. However, the underlying mechanisms through which arsenic induces cardiovascular toxic effects remain unclear. In this regard, epigenetic mechanisms have emerged as a probable connection between environment and disease phenotypes, including cardiovascular diseases. Therefore, this study aimed to evaluate epigenetic changes related to cardiotoxicity (miR-126 and miR-155 expression levels) in children from San Luis Potosi, Mexico exposed to inorganic arsenic. From 2014 to 2015, in a cross-sectional study, children (aged 6-12 years; n = 73) attending public schools at the studied sites were enrolled to take part in this study. Urinary arsenic was used as an exposure biomarker and analyzed by an atomic absorption spectrophotometry technique. On the other hand, miR-126 and miR-155 expression levels were evaluated by qRT-PCR. A mean urinary arsenic level of 30.5 ± 25.5 μg/g of creatinine was found. Moreover, the data showed a significant negative association (p < 0.05) between urinary arsenic concentrations and plasma miR-126 levels. However, an association between urinary arsenic concentrations and plasma miR-155 levels was not found (p > 0.05). In this regard, some investigations have shown an association between diminished plasma miR-126 levels and cardiovascular illnesses. The results found in this study are of concern. However, more similar studies including a larger sample size are necessary in order to clarify the real significance of the data.

Methylated Arsenic in the Southern North Sea

NASA Astrophysics Data System (ADS)

Millward, G. E.; Kitts, H. J.; Comber, S. D. W.; Ebdon, L.; Howard, A. G.

1996-07-01

Water samples collected in the southern North Sea in August 1988 (mid-summer), April 1989 (spring), September/October 1989 (late summer) and May 1990 were analysed for dissolved inorganic arsenic, monomethylarsenic (MMA) and dimethylarsenic (DMA). In mid-summer 1988, both MMA and DMA were observed throughout the southern North Sea, with lowest concentrations of dissolved inorganic arsenic (mean 6·48 nmol l -1) and the highest proportions of methylated arsenic (29%) being found in highly productive continental coastal waters. In April 1989, waters of the North Sea had a mean inorganic arsenic concentration of 12 nmol l -1and methylated species were not detected, even though phytoplankton blooms were present. Shipboard phytoplankton incubation studies (in May 1990) revealed that uptake of dissolved inorganic arsenic occurred at a rate of 0·57 nmol l -1 day -1, but the appearance of dissolved methylated species was not observed. During September/October 1989, while MMA and DMA were present in all sectors of the North Sea, the relative proportion of methylated compounds (11%) in continental coastal waters was less than mid-summer 1988. It was shown that estuarine, porewater and atmospheric inputs of arsenic species were relatively small during the observational periods, and that almost all of the methylated compounds originated from decaying algal tissue. Demethylation of DMA and MMA throughout winter contributed to the dissolved inorganic arsenic pool. The results are discussed in the context of the development of a predictive model for the cycling of arsenic in the North Sea.

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

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

Inorganic Arsenic Emissions from Glass Manufacturing Plants: National Emission Standards for Hazardous Air Pollutants (NESHAP) -- 40 CFR Part 61 Subpart N

EPA Pesticide Factsheets

Learn about the NESHAP for inorganic arsenic from glass manufacturing plants by reading the rule summary, the rule history, the code of federal regulations text, additional resources and related rules

Whole-house arsenic water treatment provided more effective arsenic exposure reduction than point-of-use water treatment at New Jersey homes with arsenic in well water

PubMed Central

Spayd, Steven E.; Robson, Mark G.; Buckley, Brian T.

2014-01-01

A comparison of the effectiveness of whole house (point-of-entry) and point-of-use arsenic water treatment systems in reducing arsenic exposure from well water was conducted. The non-randomized observational study recruited 49 subjects having elevated arsenic in their residential home well water in New Jersey. The subjects obtained either point-of-entry or point-of-use arsenic water treatment. Prior ingestion exposure to arsenic in well water was calculated by measuring arsenic concentrations in the well water and obtaining water-use histories for each subject, including years of residence with the current well and amount of water consumed from the well per day. A series of urine samples were collected from the subjects, some starting before water treatment was installed and continuing for at least nine months after treatment had begun. Urine samples were analyzed and speciated for inorganic-related arsenic concentrations. A two-phase clearance of inorganic-related arsenic from urine and the likelihood of a significant body burden from chronic exposure to arsenic in drinking water were identified. After nine months of water treatment the adjusted mean of the urinary inorganic-related arsenic concentrations were significantly lower (p < 0.0005) in the point-of-entry treatment group (2.5 μg/g creatinine) than in the point-of-use treatment group (7.2 μg/g creatinine). The results suggest that whole house arsenic water treatment systems provide a more effective reduction of arsenic exposure from well water than that obtained by point-of-use treatment. PMID:24975493

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.

ARSENIC MODE OF ACTION AND DEVELOPING A BBDR MODEL

EPA Science Inventory

The current USEPA cancer risk assessment for inorganic arsenic is based on a linear extrapolation of the epidemiological data from exposed populations in Taiwan. However, proposed key events in the mode of action (MoA) for arsenic-induced cancer (which may include altered DNA me...

Inorganic species of arsenic in soil solution determined by microcartridges and ferrihydrite-based diffusive gradient in thin films (DGT).

PubMed

Moreno-Jiménez, Eduardo; Six, Laetitia; Williams, Paul N; Smolders, Erik

2013-01-30

The bioavailability of soil arsenic (As) is determined by its speciation in soil solution, i.e., arsenite [As(III)] or arsenate [As(V)]. Soil bioavailability studies require suitable methods to cope with small volumes of soil solution that can be speciated directly after sampling, and thereby minimise any As speciation change during sample collection. In this study, we tested a self-made microcartridge to separate both As species and compared it to a commercially available cartridge. In addition, the diffusive gradient in thin films technique (DGT), in combination with the microcartridges, was applied to synthetic solutions and to a soil spiked with As. This combination was used to improve the assessment of available inorganic As species with ferrihydrite(FH)-DGT, in order to validate the technique for environmental analysis, mainly in soils. The self-made microcartridge was effective in separating As(III) from As(V) in solution with detection by inductively coupled plasma optical emission spectrometry (ICP-OES) in volumes of only 3 ml. The DGT study also showed that the FH-based binding gels are effective for As(III) and As(V) assessment, in solutions with As and P concentrations and ionic strength commonly found in soils. The FH-DGT was tested on flooded and unflooded As spiked soils and recoveries of As(III) and As(V) were 85-104% of the total dissolved As. This study shows that the DGT with FH-based binding gel is robust for assessing inorganic species of As in soils. Copyright © 2012 Elsevier B.V. All rights reserved.

Arsenic in Food

MedlinePlus

... It is found in water, air, food, and soil in organic and inorganic forms. The FDA has ... of arsenic compounds in water, food, air, and soil: organic and inorganic (these together are referred to ...

Biotransformation and detoxification of inorganic arsenic in Bombay oyster Saccostrea cucullata.

PubMed

Zhang, Wei; Guo, Zhiqiang; Zhou, Yanyan; Liu, Huaxue; Zhang, Li

2015-01-01

Arsenic (As) exists as the toxic inorganic forms in marine water and sediment, while marine oysters usually accumulate high As contents mostly as the less toxic organic forms. It has not yet been clear that how As is biotransformed in marine oysters. This study therefore investigated the biotransformation and detoxification of two inorganic As forms (As(III) and As(V)) in Bombay oyster Saccostrea cucullata after waterborne exposures for 30 days. Seven treatments of dissolved As exposure (clean seawater, 1, 5, 20 mg/L As(III), and 1, 5, 20 mg/L As(V)) were performed. Body As concentration increased significantly after all As exposure treatments except 1mg/L As(V). Total As, As(III), and As(V) concentration were positive correlated with glutathione-S-transferases (GST) activities, suggesting GST might play an important role in the As biotransformation and detoxification process. Organic As species were predominant in control and the low As exposed oysters, whereas a large fraction of As was remained as the inorganic forms in the high As exposed oysters, suggesting As could be biotransformed efficiently in the oysters in clean or light contaminated environment. The results of As speciation demonstrated the As biotransformation in the oysters included As(V) reduction, methylation to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), and subsequent conversion to arsenobetaine (AsB). More As was distributed in the subcellular metallothionein-like proteins fraction (MTLP) functioning sequestration and detoxification in the inorganic As exposed oysters, suggesting it was also a strategy for oysters against As stress. In summary, this study elucidated that marine oysters had high ability to accumulate, biotransform, and detoxify inorganic As. Copyright © 2014 Elsevier B.V. All rights reserved.

Inorganic arsenic in starchy roots, tubers, and plantain and assessment of cancer risk of sub-Saharan African populations

USDA-ARS?s Scientific Manuscript database

Starchy roots, tubers, and plantain (RTP) are the staple food in sub-Saharan Africa, and also important energy sources in Asia, Europe, and America. In this work, inorganic arsenic (iAs) in these crops was quantified by hydride generation-atomic fluorescence spectrometry (HG-AFS) after solid phase e...

COMMONALITIES IN METABOLISM OF ARSENICALS

EPA Science Inventory

Elucidating the pathway of inorganic arsenic metabolism shows that some of methylated arsenicals formed as intermediates and products are reactive and toxic species. Hence, methylated arsenicals likely mediate at least some of the toxic and carcinogenic effects associated with e...

Evaluation of the Content of Antimony, Arsenic, Bismuth, Selenium, Tellurium and Their Inorganic Forms in Commercially Baby Foods.

PubMed

Ruiz-de-Cenzano, M; Rochina-Marco, A; Cervera, M L; de la Guardia, M

2017-12-01

Baby foods, from the Spanish market and prepared from meat, fish, vegetables, cereals, legumes, and fruits, were analyzed to obtain the concentration of antimony (Sb), arsenic (As), bismuth (Bi), and tellurium (Te) as toxic elements and selenium (Se) as essential element. An analytical procedure was employed based on atomic fluorescence spectroscopy which allowed to obtain accurate data at low levels of concentration. Values of 14 commercial samples, expressed in nanograms per gram fresh weight, ranged for Sb 0.66-6.9, As 4.5-242, Te 1.35-2.94, Bi 2.18-4.79, and Se 5.4-109. Additionally, speciation studies were performed based on data from a non-chromatographic screening method. It was concluded that tellurium and bismuth were mainly present as inorganic forms and selenium as organic form, and antimony and arsenic species depend on the ingredients of each baby food. Risk assessment considerations were made by comparing dietary intake of the aforementioned elements through the consumption of one baby food portion a day and recommended or tolerable guideline values.

PROPOSED CARCINOGENIC MECHANISMS FOR ARSENIC

EPA Science Inventory

PROPOSED CARCINOGENIC MECHANISMS FOR ARSENIC.

Arsenic is a human carcinogen in skin, lung, liver, urinary bladder and kidney. In contrast,
there is no accepted experimental animal model of inorganic arsenic carcinogenesis.
Proposed mechanisms/modes of action for a...

*Arsenic (+3 oxidation state) methyltransferase and the methylation of arsenicals in the invertebrate chordate ciona intestinalis

EPA Science Inventory

Biotransformation of inorganic arsenic (iAs) involves methylation catalyzed by arsenic (+3 oxidation state) methyltransferase (As3mt) , yielding mono-, di-, and trimethylated arsenicals. A comparative genomic approach focused on Ciona intestinaJis, an invertebrate chordate, was u...

Arsenic speciation and fucoxanthin analysis from seaweed dietary supplements using LC-MS

USDA-ARS?s Scientific Manuscript database

Inorganic species are considered more toxic to humans than organic arsenic and total arsenic. Analysis of total arsenic in metallic form, organic and inorganic arsenic species from seaweeds and dietary supplements using LC-ICP-MS was developed. Solvent extraction with sonication and microwave extr...

Gene Expression of Normal Human Epidermal Keratinocytes Modulated by Trivalent Arsenicals

EPA Science Inventory

Chronic exposure to inorganic arsenic (iAs) is associated with the development of benign and malignant human skin lesions including nonmelanoma skin cancers. The precise arsenical form(s) responsible for this carcinogenic effect are unknown, although trivalent inorganic arsenic (...

TISSUE DISTRIBUTION OF INORGANIC ARSENIC (AS) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (ASV)

EPA Science Inventory

TISSUE DISTRIBUTION OF INORGANIC ARSENIC (iAs) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (AsV). E M Kenyon1, L M Del Razo2, and M F Hughes1. 1NHEERL, ORD, US EPA, RTP, NC, USA; 2CINVESTAV-IPN, Mexico City, Mexico.

The relationship o...

Comments on the Draft U.S. EPA Document Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System (IRIS)

EPA Pesticide Factsheets

The Organic Arsenical Products Task Force (OAPTF) hereby submits the appended list of materials from the scientific literature on inorganic arsenic for inclusion in the U.S. Environmental Protection Agency's (EPA) docket maintained in support of the Summary Information on the Integrated Risk Information System (IRIS) Report (Report)

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)].

Dose-dependent urinary phenotype of inorganic arsenic methylation in mice with a focus on trivalent methylated metabolites.

PubMed

García-Montalvo, Eliud A; Valenzuela, Olga L; Sánchez-Peña, Luz C; Albores, Arnulfo; Del Razo, Luz M

2011-11-01

Inorganic arsenic (iAs) exposure has been associated with the increased risk of various forms of cancer and of non-cancerous diseases. Metabolic conversions of iAs that yield highly toxic and genotoxic methylarsonite (MAsIII) and dimethylarsinite (DMAsIII) may play a significant role in determining the extent and character of toxic and cancer-promoting effects of iAs exposure. However, in vivo research involving the production of MAsIII and DMAsIII remains an area of ongoing investigation and debate. The results of metabolic and toxicity studies using mice have been entirely applicable to other species including humans. The goal of this study was to investigate the phenotype for the trivalent and pentavalent arsenic metabolites in relation to arsenite dose via immediate analysis of fresh urine samples, while preventing the oxidation of unstable methylated AsIII-containing metabolites. Female mice (C57BL/6) received sodium arsenite by gavage at doses of 0, 3, 6 or 10 mg As/kg/day for 9 days, after which trivalent methylated arsenicals were detected in 100% of urine samples; these arsenicals were not detected in the urine of control mice. The amount of DMAsIII detected in urine depended on the dose of arsenite administered and was determined to be 50.2%, 31.4% and 16.5% of the total urinary arsenic in mice exposed to 3, 6, or 10 mg/kg/day, respectively. This relationship is consistent with the hypothesis of inhibition or saturation of iAs methylation. Understanding the in vivo production of MAsIII and DMAsIII in mice exposed to iAs could aid in developing a biologically based dose-response model for iAs.

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

EPA Science Inventory

Arsenic (+3 oxidation state) methyltransferase (As3mt) catalyzes methylation of inorganic arsenic producing a number of methylated arsenic metabolites. Although methylation has been commonly considered a pathway for detoxification of arsenic, some highly reactive methylated ars...

Urinary Trivalent Methylated Arsenic Species in a Population Chronically Exposed to Inorganic Arsenic

PubMed Central

Valenzuela, Olga L.; Borja-Aburto, Victor H.; Garcia-Vargas, Gonzalo G.; Cruz-Gonzalez, Martha B.; Garcia-Montalvo, Eliud A.; Calderon-Aranda, Emma S.; Del Razo, Luz M.

2005-01-01

Chronic exposure to inorganic arsenic (iAs) has been associated with increased risk of various forms of cancer and of noncancerous diseases. Metabolic conversions of iAs that yield highly toxic and genotoxic methylarsonite (MAsIII) and dimethylarsinite (DMAsIII) may play a significant role in determining the extent and character of toxic and cancer-promoting effects of iAs exposure. In this study we examined the relationship between urinary profiles of MAsIII and DMAsIII and skin lesion markers of iAs toxicity in individuals exposed to iAs in drinking water. The study subjects were recruited among the residents of an endemic region of central Mexico. Drinking-water reservoirs in this region are heavily contaminated with iAs. Previous studies carried out in the local populations have found an increased incidence of pathologies, primarily skin lesions, that are characteristic of arseniasis. The goal of this study was to investigate the urinary profiles for the trivalent and pentavalent As metabolites in both high- and low-iAs–exposed subjects. Notably, methylated trivalent arsenicals were detected in 98% of analyzed urine samples. On average, the major metabolite, DMAsIII, represented 49% of total urinary As, followed by DMAsV (23.7%), iAsV (8.6%), iAsIII (8.5%), MAsIII (7.4%), and MAsV (2.8%). More important, the average MAsIII concentration was significantly higher in the urine of exposed individuals with skin lesions compared with those who drank iAs-contaminated water but had no skin lesions. These data suggest that urinary levels of MAsIII, the most toxic species among identified metabolites of iAs, may serve as an indicator to identify individuals with increased susceptibility to toxic and cancer-promoting effects of arseniasis. PMID:15743710

78 FR 42086 - Draft Guidance for Industry on Arsenic in Apple Juice: Action Level; Supporting Document for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-15

... Level for Arsenic in Apple Juice; A Quantitative Assessment of Inorganic Arsenic in Apple Juice... Arsenic in Apple Juice'' (the draft supporting document) and ``A Quantitative Assessment of Inorganic... document entitled ``A Quantitative Assessment of Inorganic Arsenic in Apple Juice.'' The draft guidance...

Role of Metabolism in Arsenic-Induced Toxicity: Identification and Quantification of Arsenic Metabolites in Tissues and Excreta

EPA Science Inventory

Arsenic is a known toxicant and carcinogen. Methylation of inorganic arsenic was once thought to be a detoxification mechanism because of the rapid excretion and relatively lower toxicity of the pentavalent organic arsenical metabolites. Advances in analytical chemistry have al...

PROXIMATE OR ULTIMATE GENOTOXIC FORMS OF ARSENIC: METHYLATED ARSENIC(III) SPECIES THAT REACT DIRECTLY WITH DNA

EPA Science Inventory

PROXIMATE OR ULTIMATE GENOTOXIC FORMS OF ARSENIC: METHYLATED ARSENIC(III) SPECIES THAT REACT DIRECTL Y WITH DNA.

Abstract:

Although inorganic arsenic (iAs), arsenite or arsenate, is genotoxic, there has been no demonstration that iAs or a methylated metabolite...

Femtomolar level sensing of inorganic arsenic(III) in water and in living-systems using a non-toxic fluorescent probe.

PubMed

Dey, Biswajit; Mukherjee, Priyanka; Mondal, Ranjan Kumar; Chattopadhyay, Asoke Prasun; Hauli, Ipsit; Mukhopadhyay, Subhra Kanti; Fleck, Michel

2014-12-14

A highly selective femtomolar level sensing of inorganic arsenic(III) as arsenious acid has been accomplished in water medium and in living-systems (on pollen grains of Tecoma stans; Candida albicans cells (IMTECH No. 3018) and Peperomia pellucida stem section) using a non-toxic fluorescent probe of a Cu(II)-complex.

Pharmacodynamics of S-dimethylarsino-glutathione, a putative metabolic intermediate of inorganic arsenic, in mice.

PubMed

Kato, Ayaka; Kobayashi, Yayoi; Udagawa, Osamu; Hirano, Seishiro

2017-02-15

Inorganic arsenicals are well-known carcinogens, whereas arsenite (iAs III ) compounds are now recognized as potent therapeutic agents for several leukemias, and arsenic trioxide has been used for the treatment of recurrent acute promyelocytic leukemia (APL). However, recent clinical trials revealed that arsenite is not always effective for non-APL malignancies. Another arsenical, S-dimethylarsino-glutathione ([DMA III (GS)]), which is a putative metabolic intermediate in the hepatic metabolism of iAs III , shows promise for treating several types of lymphoma. However, the metabolism of [DMA III (GS)] has not been well investigated, probably because [DMA III (GS)] is not stable in biological fluids where the concentration of glutathione is low. In the present study, we injected [DMA III (GS)] intravenously into mice and compared the tissue distribution and metabolic dynamics of [DMA III (GS)] with those of sodium arsenite (NaAsO 2 ). We found a unique organ preference for the distribution of [DMA III (GS)] to the lung and brain in comparison to NaAsO 2 . Furthermore, [DMA III (GS)] appeared to bind to serum albumin by exchanging its glutathione moiety quickly after administration, providing novel insights into the longer retention of [DMA III (GS)] in plasma. Copyright © 2016 Elsevier Inc. All rights reserved.

Estimating Inorganic Arsenic Exposure from U.S. Rice and Total Water Intakes

PubMed Central

Mantha, Madhavi; Yeary, Edward; Trent, John; Creed, Patricia A.; Kubachka, Kevin; Hanley, Traci; Shockey, Nohora; Heitkemper, Douglas; Caruso, Joseph; Xue, Jianping; Rice, Glenn; Wymer, Larry

2017-01-01

Background: Among nonoccupationally exposed U.S. residents, drinking water and diet are considered primary exposure pathways for inorganic arsenic (iAs). In drinking water, iAs is the primary form of arsenic (As), while dietary As speciation techniques are used to differentiate iAs from less toxic arsenicals in food matrices. Objectives: Our goal was to estimate the distribution of iAs exposure rates from drinking water intakes and rice consumption in the U.S. population and ethnic- and age-based subpopulations. Methods: The distribution of iAs in drinking water was estimated by population, weighting the iAs concentrations for each drinking water utility in the Second Six-Year Review data set. To estimate the distribution of iAs concentrations in rice ingested by U.S. consumers, 54 grain-specific, production-weighted composites of rice obtained from U.S. mills were extracted and speciated using both a quantitative dilute nitric acid extraction and speciation (DNAS) and an in vitro gastrointestinal assay to provide an upper bound and bioaccessible estimates, respectively. Daily drinking water intake and rice consumption rate distributions were developed using data from the What We Eat in America (WWEIA) study. Results: Using these data sets, the Stochastic Human Exposure and Dose Simulation (SHEDS) model estimated mean iAs exposures from drinking water and rice were 4.2μg/day and 1.4μg/day, respectively, for the entire U.S. population. The Tribal, Asian, and Pacific population exhibited the highest mean daily exposure of iAs from cooked rice (2.8μg/day); the mean exposure rate for children between ages 1 and 2 years in this population is 0.104μg/kg body weight (BW)/day. Conclusions: An average consumer drinking 1.5 L of water daily that contains between 2 and 3 ng iAs/mL is exposed to approximately the same amount of iAs as a mean Tribal, Asian, and Pacific consumer is exposed to from rice. https://doi.org/10.1289/EHP418 PMID:28572075

Inorganic Arsenic Induces NRF2-Regulated Antioxidant Defenses in Both Cerebral Cortex and Hippocampus in Vivo.

PubMed

Zhang, Yang; Duan, Xiaoxu; Li, Jinlong; Zhao, Shuo; Li, Wei; Zhao, Lu; Li, Wei; Nie, Huifang; Sun, Guifang; Li, Bing

2016-08-01

Inorganic arsenic is reported to induce the reactive oxygen species-mediated oxidative stress, which is supposed to be one of the main mechanisms of arsenic-related neurological diseases. Nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of antioxidant defense systems, up-regulates the expression of target genes to fight against oxidative damages caused by harmful substances, including metals. In the present study, mice were used as a model to investigate the oxidative stress levels and the expressions of NRF2-regulated antioxidant substances in both cerebral cortex and hippocampus with 5, 10 and 20 mg/kg NaAsO2 exposure intra-gastrically. Our results showed that acute NaAsO2 treatment resulted in decreased total anti-oxidative capacity (T-AOC) and increased maleic dialdehyde production in the nervous system. We also detected rapidly elevation of NRF2 protein levels by enhancement of Nrf2 transcription, especially at 20 mg/kg NaAsO2 exposure group. In the meantime, mRNA and protein levels of Nrf2 encoding antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H: quinine oxidoreductase 1 (NQO1) and glutathione S-transferase (GST) were consistently elevated time- and dose-dependently both in the cerebral cortex and hippocampus. Taken together, the presence study demonstrated the activation of NRF2 pathway, an early antioxidant defensive response, in both cerebral cortex and hippocampus upon inorganic arsenic (iAs) exposure in vivo. A better knowledge on the roles of NRF2 pathway in maintaining cellular redox homeostasis would be helpful for the strategies on improvement of neurotoxicity related to this metalloid.

Comparative Distribution and Retention of Arsenic in Arsenic (+3 Oxidation State) Methyltransferase Knockout and Wild Type Mice

EPA Science Inventory

The mouse arsenic (+3 oxidation state) methyltransferase (As3mt) gene encodes a ~ 43 kDa protein that catalyzes conversion of inorganic arsenic into methylated products. Heterologous expression of AS3MT or its silencing by RNA interference controls arsenic methylation phenotypes...

Biological monitoring of occupational exposure to inorganic arsenic.

PubMed

Apostoli, P; Bartoli, D; Alessio, L; Buchet, J P

1999-12-01

This study was undertaken to assess reliable biological indicators for monitoring the occupational exposure to inorganic arsenic (iAs), taking into account the possible confounding role of arsenicals present in food and of the element present in drinking water. 51 Glass workers exposed to As trioxide were monitored by measuring dust in the breathing zone, with personal air samplers. Urine samples at the end of work shift were analysed for biological monitoring. A control group of 39 subjects not exposed to As, and eight volunteers who drank water containing about 45 micrograms/l iAs for a week were also considered. Plasma mass spectrometry (ICP-MS) was used for the analysis of total As in air and urine samples, whereas the urinary As species (trivalent, As3; pentavalent, As5; monomethyl arsonic acid, MMA; dimethyl arsinic acid, DMA; arsenobetaine, AsB) were measured by liquid chromatography coupled with plasma mass spectrometry (HPLC-MS) RESULTS: Environmental concentrations of As in air varied widely (mean 84 micrograms/m3, SD 61, median 40) and also the sum of urinary iAs MMA and DMA, varied among the groups of exposed subjects (mean 106 micrograms/l, SD 84, median 65). AsB was the most excreted species (34% of total As) followed by DMA (28%), MMA (26%), and As3 + As5 (12%). In the volunteers who drank As in the water the excretion of MMA and DMA increased (from a median of 0.5 to 5 micrograms/day for MMA and from 4 to 13 micrograms/day for DMA). The best correlations between As in air and its urinary species were found for total iAs and As3 + As5. To avoid the effect of As from sources other than occupation on urinary species of the element, in particular on DMA, it is proposed that urinary As3 + As5 may an indicator for monitoring the exposure to iAs. For concentrations of 10 micrograms/m3 the current environmental limit for iAs, the limit for urinary As3 + As5 was calculated to be around 5 micrograms/l, even if the wide variation of values needs critical

RE:RE: Comments on the Draft US EPA Document Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System (IRIS).

EPA Pesticide Factsheets

Letter from the Organic Arsenical Products Task Force expressing concern about aspects of the Science Advisory Board Workgroup's review of a draft document Toxicological Review of Inorganic Arsenic: In Support of the Summary Information on the Integrated Risk Information System (IRIS) and decision not to grant more time to prepare for meeting.

The Association of Urine Arsenic with Prevalent and Incident Chronic Kidney Disease: Evidence from the Strong Heart Study

PubMed Central

Zheng, Laura Y.; Umans, Jason G.; Yeh, Fawn; Francesconi, Kevin A.; Goessler, Walter; Silbergeld, Ellen K; Bandeen-Roche, Karen; Guallar, Eliseo; Howard, Barbara V.; Weaver, Virginia M.; Navas-Acien, Ana

2016-01-01

Background Few studies have evaluated associations between low to moderate arsenic levels and chronic kidney disease (CKD). The objective was to evaluate the associations of inorganic arsenic exposure with prevalent and incident CKD in American Indian adults. Methods We evaluated the associations of inorganic arsenic exposure with CKD in American Indians who participated in the Strong Heart Study (SHS) in 3,851 adults aged 45–74 years in a cross-sectional analysis, and 3,119 adults with follow-up data in a prospective analysis. Inorganic arsenic, monomethylarsonate, and dimethylarsinate were measured in urine at baseline. CKD was defined as eGFR≤60 mL/min/1.73m2, kidney transplant or dialysis. Results CKD prevalence was 10.3%. The median (IQR) concentration of inorganic plus methylated arsenic species (total arsenic) in urine was 9.7 (5.8, 15.7) μg/L. The adjusted OR (95% CI) of prevalent CKD for an interquartile range in total arsenic was 0.7 (0.6, 0.8), mostly due to an inverse association with inorganic arsenic (OR 0.4 (0.3, 0.4)). Monomethylarsonate and dimethylarsinate were positively associated with prevalent CKD after adjustment for inorganic arsenic (OR 3.8 and 1.8). The adjusted HR of incident CKD for an IQR in ΣAs was 1.2 (1.03, 1.41). The corresponding HR for inorganic arsenic, monomethylarsonate and dimethylarsinate were 1.0 (0.9, 1.2), 1.2 (1.00, 1.3) and 1.2 (1.0, 1.4). Conclusions The inverse association of urine inorganic arsenic with prevalent CKD suggests that kidney disease affects excretion of inorganic arsenic. Arsenic species were positively associated with incident CKD. Studies with repeated measures are needed to further characterize the relationship between arsenic and kidney disease development. PMID:25929811

Biotransformation of inorganic arsenic in a marine herbivorous fish Siganus fuscescens after dietborne exposure.

PubMed

Zhang, Wei; Chen, Lizhao; Zhou, Yanyan; Wu, Yun; Zhang, Li

2016-03-01

Arsenic (As) is well known to be biodiminished along marine food chains. The marine herbivorous fish at a lower trophic level are expected to accumulate more As. However, little is known about how marine herbivorous fish biotransform the potential high As bioaccumulation. Therefore, the present study quantified the biotransformation of two inorganic As species (As(III) and As(V)) in a marine herbivorous fish Siganus fuscescens following dietborne exposure. The fish were fed on As contaminated artificial diets at nominal concentrations of 400 and 1500 μg As(III) or As(V) g(-1) (dry weight) for 21 d and 42 d. After exposure, As concentrations in intestine, liver, and muscle tissues of rabbitfish increased significantly and were proportional to the inorganic As exposure concentrations. The present study demonstrated that both inorganic As(III) and As(V) in the dietborne phases were able to be biotransformed to the less toxic arsenobetaine (AsB) (63.3-91.3% in liver; 79.0%-95.2% in muscle). The processes of As biotransformation in rabbitfish could include oxidation of As(III) to As(V), reduction of As(V) to As(III), methylation to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), and subsequent conversion to AsB. These results also demonstrated that AsB synthesis processes were diverse facing different inorganic As species in different tissues. In summary, the present study elucidated that marine herbivorous fish had high ability to biotransform inorganic As to the organic forms (mainly AsB), resulting in high As bioaccumulation. Therefore, marine herbivorous fish could detoxify inorganic As in the natural environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

ARSENIC (III) METHYLATED SPECIES REACT WITH DNA DIRECTLY AND COULD BE PROXIMATED/ULTIMATE GENOTOXIC FORMS OF ARSENIC

EPA Science Inventory

ARSENIC(III) METHYLATED SPECIES REACT WITH DNA DIRECTL Y AND COULD BE PROXIMATE/ULTIMATE GENOTOXIC FORMS OF ARSENIC


Arsenite and arsenate (iAs, inorganic arsenic) have been thought to act as genotoxicants without reacting directly with DNA; neither iAs nor As(V) m...

A Pilot Study: The importance of inter-individual differences in inorganic arsenic metabolism for birth weight outcome

PubMed Central

Gelmann, Elyssa R; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Kunrath, Julie

2013-01-01

Inorganic arsenic (iAs) exposure is detrimental to birth outcome. We lack information regarding the potential for iAs metabolism to affect fetal growth. Our pilot study evaluated postpartum Romanian women with known birth weight outcome for differences in iAs metabolism. Subjects were chronically exposed to low-to-moderate drinking water iAs. We analyzed well water, arsenic metabolites in urine, and toenail arsenic. Urine iAs and metabolites, toenail iAs, and secondary methylation efficiency increased as an effect of exposure (p<0.001). Urine iAs and metabolites showed a significant interaction effect between exposure and birth weight. Moderately exposed women with low compared to normal birth weight outcome had greater metabolite excretion (p<0.03); 67% with low compared to 10% with normal birth weight outcome presented urine iAs >9μg/L (p=0.019). Metabolic partitioning of iAs toward excretion may impair fetal growth. Prospective studies on iAs excretion before and during pregnancy may provide a biomarker for poor fetal growth risk. PMID:24211595

GLUTATHIONE MODULATES RECOMBINANT RAT ARSENIC (+3 OXIDATION STATE) METHYLTRANSFERASE-CATALYZED FORMATION OF TRIMETHYLARSINE OXIDE AND TRIMETHYLARSINE

EPA Science Inventory

Humans and other species enzymatically convert inorganic arsenic into methylated metabolites. Although the major metabolites are mono- and dimethylated arsenicals, trimethylated arsenicals have been detected in urine following exposure to inorganic arsenic. The AS3MT gene e...

ARSENIC - SUSCEPTIBILITY & IN UTERO EFFECTS

EPA Science Inventory

Exposure to inorganic arsenic remains a serious public health problem at many locations worldwide. If has often been noted that prevalences of signs and symptoms of chronic arsenic poisoning differ among various populations. For example, skin lesions or peripheral vascular dis...

Biologically based modeling of multimedia, multipathway, multiroute population exposures to arsenic

PubMed Central

Georgopoulos, Panos G.; Wang, Sheng-Wei; Yang, Yu-Ching; Xue, Jianping; Zartarian, Valerie G.; Mccurdy, Thomas; Özkaynak, Halûk

2011-01-01

This article presents an integrated, biologically based, source-to-dose assessment framework for modeling multimedia/multipathway/multiroute exposures to arsenic. Case studies demonstrating this framework are presented for three US counties (Hunderton County, NJ; Pima County, AZ; and Franklin County, OH), representing substantially different conditions of exposure. The approach taken utilizes the Modeling ENvironment for TOtal Risk studies (MENTOR) in an implementation that incorporates and extends the approach pioneered by Stochastic Human Exposure and Dose Simulation (SHEDS), in conjunction with a number of available databases, including NATA, NHEXAS, CSFII, and CHAD, and extends modeling techniques that have been developed in recent years. Model results indicate that, in most cases, the food intake pathway is the dominant contributor to total exposure and dose to arsenic. Model predictions are evaluated qualitatively by comparing distributions of predicted total arsenic amounts in urine with those derived using biomarker measurements from the NHEXAS — Region V study: the population distributions of urinary total arsenic levels calculated through MENTOR and from the NHEXAS measurements are in general qualitative agreement. Observed differences are due to various factors, such as interindividual variation in arsenic metabolism in humans, that are not fully accounted for in the current model implementation but can be incorporated in the future, in the open framework of MENTOR. The present study demonstrates that integrated source-to-dose modeling for arsenic can not only provide estimates of the relative contributions of multipathway exposure routes to the total exposure estimates, but can also estimate internal target tissue doses for speciated organic and inorganic arsenic, which can eventually be used to improve evaluation of health risks associated with exposures to arsenic from multiple sources, routes, and pathways. PMID:18073786

High resolution profile of inorganic aqueous geochemistry and key redox zones in an arsenic bearing aquifer in Cambodia.

PubMed

Richards, Laura A; Magnone, Daniel; Sovann, Chansopheaktra; Kong, Chivuth; Uhlemann, Sebastian; Kuras, Oliver; van Dongen, Bart E; Ballentine, Christopher J; Polya, David A

2017-07-15

Arsenic contamination of groundwaters in South and Southeast Asia is a major threat to public health. In order to better understand the geochemical controls on the mobility of arsenic in a heavily arsenic-affected aquifer in northern Kandal Province, Cambodia, key changes in inorganic aqueous geochemistry have been monitored at high vertical and lateral resolution along dominant groundwater flow paths along two distinct transects. The two transects are characterized by differing geochemical, hydrological and lithological conditions. Arsenic concentrations in groundwater are highly heterogenous, and are broadly positively associated with iron and negatively associated with sulfate and dissolved oxygen. The observed correlations are generally consistent with arsenic mobilization by reductive-dissolution of iron (hydr)oxides. Key redox zones, as identified using groupings of the PHREEQC model equilibrium electron activity of major redox couples (notably ammonium/nitrite; ammonium/nitrate; nitrite/nitrate; dissolved oxygen/water) have been identified and vary with depth, site and season. Mineral saturation is also characterized. Seasonal changes in groundwater chemistry were observed in areas which were (i) sandy and of high permeability; (ii) in close proximity to rivers; and/or (iii) in close proximity to ponds. Such changes are attributed to monsoonal-driven surface-groundwater interactions and are consistent with the separate provenance of recharge sources as identified using stable isotope mixing models. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Chronic arsenic exposure increases TGFalpha concentration in bladder urothelial cells of Mexican populations environmentally exposed to inorganic arsenic☆

PubMed Central

Valenzuela, Olga L.; Germolec, Dori R.; Borja-Aburto, Víctor H.; Contreras-Ruiz, José; García-Vargas, Gonzalo G.; Del Razo, Luz M.

2009-01-01

Inorganic arsenic (iAs) is a well-established carcinogen and human exposure has been associated with a variety of cancers including those of skin, lung, and bladder. High expression of transforming growth factor alpha (TGF-α) has associated with local relapses in early stages of urinary bladder cancer. iAs exposures are at least in part determined by the rate of formation and composition of iAs metabolites (MAsIII, MAsV, DMAsIII, DMAsV). This study examines the relationship between TGF-α concentration in exfoliated bladder urothelial cells (BUC) separated from urine and urinary arsenic species in 72 resident women (18-51 years old) from areas exposed to different concentrations of iAs in drinking water (2-378 ppb) in central Mexico. Urinary arsenic species, including trivalent methylated metabolites were measured by hydride generation atomic absorption spectrometry method. The concentration of TGF-α in BUC was measured using an ELISA assay. Results show a statistically significant positive correlation between TGF-α concentration in BUC and each of the six arsenic species present in urine. The multivariate linear regression analyses show that the increment of TGF-α levels in BUC was importantly associated with the presence of arsenic species after adjusting by age, and presence of urinary infection. People from areas with high arsenic exposure had a significantly higher TGF-α concentration in BUC than people from areas of low arsenic exposure (128.8 vs. 64.4 pg/mg protein; p<0.05). Notably, exfoliated cells isolated from individuals with skin lesions contained significantly greater amount of TGF-α than cells from individuals without skin lesions: 157.7 vs. 64.9 pg/mg protein (p=0.003). These results suggest that TGF-α in exfoliated BUC may serve as a susceptibility marker of adverse health effects on epithelial tissue in arsenic-endemic areas. PMID:17267001

Inorganic arsenic in seafood: does the extraction method matter?

PubMed

Pétursdóttir, Ásta H; Gunnlaugsdóttir, Helga; Krupp, Eva M; Feldmann, Jörg

2014-05-01

Nine different extraction methods were evaluated for three seafood samples to test whether the concentration of inorganic arsenic (iAs) determined in seafood is dependent on the extraction method. Certified reference materials (CRM) DOLT-4 (Dogfish Liver) and TORT-2 (Lobster Hepatopancreas), and a commercial herring fish meal were evaluated. All experimental work described here was carried out by the same operator using the same instrumentation, thus eliminating possible differences in results caused by laboratory related factors. Low concentrations of iAs were found in CRM DOLT-4 (0.012±0.003mgkg(-1)) and the herring fish meal sample (0.007±0.002mgkg(-1)) for all extraction methods. When comparing the concentration of iAs in CRM TORT-2 found in this study and in the literature dilute acids, HNO3 and HCl, showed the highest extracted iAs wheras dilute NaOH (in 50% ethanol) showed significantly lower extracted iAs. However, most other extraction solvents were not statistically different from one another. Copyright © 2013 Elsevier Ltd. All rights reserved.

Arsenic (+3 oxidation state) methyltransferase genotype affects steady-state distribution and clearance of arsenic in arsenate-treated mice

EPA Science Inventory

Arsenic (+3 oxidation state) methyltransferase (As3mt) catalyzes formation of mono-, di-, and tri-methylated metabolites of inorganic arsenic. Distribution and retention of arsenic were compared in adult female As3mt knockout mice and wild-type C57BL/6 mice using a regimen in whi...

Arsenic speciation in edible mushrooms.

PubMed

Nearing, Michelle M; Koch, Iris; Reimer, Kenneth J

2014-12-16

The fruiting bodies, or mushrooms, of terrestrial fungi have been found to contain a high proportion of the nontoxic arsenic compound arsenobetaine (AB), but data gaps include a limited phylogenetic diversity of the fungi for which arsenic speciation is available, a focus on mushrooms with higher total arsenic concentrations, and the unknown formation and role of AB in mushrooms. To address these, the mushrooms of 46 different fungus species (73 samples) over a diverse range of phylogenetic groups were collected from Canadian grocery stores and background and arsenic-contaminated areas. Total arsenic was determined using ICP-MS, and arsenic speciation was determined using HPLC-ICP-MS and complementary X-ray absorption spectroscopy (XAS). The major arsenic compounds in mushrooms were found to be similar among phylogenetic groups, and AB was found to be the major compound in the Lycoperdaceae and Agaricaceae families but generally absent in log-growing mushrooms, suggesting the microbial community may influence arsenic speciation in mushrooms. The high proportion of AB in mushrooms with puffball or gilled morphologies may suggest that AB acts as an osmolyte in certain mushrooms to help maintain fruiting body structure. The presence of an As(III)-sulfur compound, for the first time in mushrooms, was identified in the XAS analysis. Except for Agaricus sp. (with predominantly AB), inorganic arsenic predominated in most of the store-bought mushrooms (albeit with low total arsenic concentrations). Should inorganic arsenic predominate in these mushrooms from contaminated areas, the risk to consumers under these circumstances should be considered.

Biological monitoring of occupational exposure to inorganic arsenic

PubMed Central

Apostoli, P.; Bartoli, D.; Alessio, L.; Buchet, J. P.

1999-01-01

OBJECTIVES: This study was undertaken to assess reliable biological indicators for monitoring the occupational exposure to inorganic arsenic (iAs), taking into account the possible confounding role of arsenicals present in food and of the element present in drinking water. METHODS: 51 Glass workers exposed to As trioxide were monitored by measuring dust in the breathing zone, with personal air samplers. Urine samples at the end of work shift were analysed for biological monitoring. A control group of 39 subjects not exposed to As, and eight volunteers who drank water containing about 45 micrograms/l iAs for a week were also considered. Plasma mass spectrometry (ICP-MS) was used for the analysis of total As in air and urine samples, whereas the urinary As species (trivalent, As3; pentavalent, As5; monomethyl arsonic acid, MMA; dimethyl arsinic acid, DMA; arsenobetaine, AsB) were measured by liquid chromatography coupled with plasma mass spectrometry (HPLC-MS) RESULTS: Environmental concentrations of As in air varied widely (mean 84 micrograms/m3, SD 61, median 40) and also the sum of urinary iAs MMA and DMA, varied among the groups of exposed subjects (mean 106 micrograms/l, SD 84, median 65). AsB was the most excreted species (34% of total As) followed by DMA (28%), MMA (26%), and As3 + As5 (12%). In the volunteers who drank As in the water the excretion of MMA and DMA increased (from a median of 0.5 to 5 micrograms/day for MMA and from 4 to 13 micrograms/day for DMA). The best correlations between As in air and its urinary species were found for total iAs and As3 + As5. CONCLUSIONS: To avoid the effect of As from sources other than occupation on urinary species of the element, in particular on DMA, it is proposed that urinary As3 + As5 may an indicator for monitoring the exposure to iAs. For concentrations of 10 micrograms/m3 the current environmental limit for iAs, the limit for urinary As3 + As5 was calculated to be around 5 micrograms/l, even if the wide

Considerations in deriving quantitative cancer criteria for inorganic arsenic exposure via inhalation.

PubMed

Lewis, Ari S; Beyer, Leslie A; Zu, Ke

2015-01-01

The inhalation unit risk (IUR) that currently exists in the United States Environmental Protection Agency's (US EPA's) Integrated Risk Information System was developed in 1984 based on studies examining the relationship between respiratory cancer and arsenic exposure in copper smelters from two US locations: the copper smelter in Anaconda, Montana, and the American Smelting And Refining COmpany (ASARCO) smelter in Tacoma, Washington. Since US EPA last conducted its assessment, additional data have become available from epidemiology and mechanistic studies. In addition, the California Air Resources Board, Texas Commission of Environmental Quality, and Dutch Expert Committee on Occupational Safety have all conducted new risk assessments. All three analyses, which calculated IURs based on respiratory/lung cancer mortality, generated IURs that are lower (i.e., less restrictive) than the current US EPA value of 4.3×10(-3) (μg/m(3))(-1). The IURs developed by these agencies, which vary more than 20-fold, are based on somewhat different studies and use different methodologies to address uncertainties in the underlying datasets. Despite these differences, all were developed based on a cumulative exposure metric assuming a low-dose linear dose-response relationship. In this paper, we contrast and compare the analyses conducted by these agencies and critically evaluate strengths and limitations inherent in the data and methodologies used to develop quantitative risk estimates. In addition, we consider how these data could be best used to assess risk at much lower levels of arsenic in air, such as those experienced by the general public. Given that the mode of action for arsenic supports a threshold effect, and epidemiological evidence suggests that the arsenic concentration in air is a reliable predictor of lung/respiratory cancer risk, we developed a quantitative cancer risk analysis using a nonlinear threshold model. Applying a nonlinear model to occupational data, we

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.

ASSESSING ARSENIC EXPOSURE AND SKIN HYPERKERATOSIS IN INNER MONGOLIA, CHINA

EPA Science Inventory

Arsenic is a known human carcinogen. The inorganic forms, especially arsenite (As+3), are believed to be the most toxic species. Methylation is often considered to be the
detoxification pathway for the metabolism of inorganic arsenic. The ground water in Ba
Men, Inner Mo...

78 FR 56719 - Draft Guidance for Industry on Arsenic in Apple Juice: Action Level; Supporting Document for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-13

... Level for Arsenic in Apple Juice; A Quantitative Assessment of Inorganic Arsenic in Apple Juice... Juice,'' and a risk assessment document entitled ``A Quantitative Assessment of Inorganic Arsenic in...

Meeting Materials for the 4th NRC Meeting on the Guidance for and the Review of EPA's Toxicological Assessment of Inorganic Arsenic

EPA Science Inventory

On December 2-3, 2015, the National Research Council (NRC) hosted the 4th meeting of the committee formed to peer review the draft IRIS assessment of inorganic arsenic. EPA presented background and overview materials during the public session on December 2nd. This information co...

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

Speciation and Localization of Arsenic in White and Brown Rice Grains

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

Meharg, Andrew A.; Lombi, Enzo; Williams, Paul N.

2008-06-30

Synchrotron-based X-ray fluorescence (S-XRF) was utilized to locate arsenic (As) in polished (white) and unpolished (brown) rice grains from the United States, China, and Bangladesh. In white rice As was generally dispersed throughout the grain, the bulk of which constitutes the endosperm. In brown rice As was found to be preferentially localized at the surface, in the region corresponding to the pericarp and aleurone layer. Copper, iron, manganese, and zinc localization followed that of arsenic in brown rice, while the location for cadmium and nickel was distinctly different, showing relatively even distribution throughout the endosperm. The localization of As inmore » the outer grain of brown rice was confirmed by laser ablation ICP?MS. Arsenic speciation of all grains using spatially resolved X-ray absorption near edge structure (?-XANES) and bulk extraction followed by anion exchange HPLC?ICP?MS revealed the presence of mainly inorganic As and dimethylarsinic acid (DMA). However, the two techniques indicated different proportions of inorganic:organic As species. A wider survey of whole grain speciation of white (n = 39) and brown (n = 45) rice samples from numerous sources (field collected, supermarket survey, and pot trials) showed that brown rice had a higher proportion of inorganic arsenic present than white rice. Furthermore, the percentage of DMA present in the grain increased along with total grain arsenic.« less

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.

RECENT ADVANCES IN ARSENIC CARCINOGENESIS: MODES OF ACTION, ANIMAL MODEL SYSTEMS AND METHYLATED ARSENIC METABOLITES

EPA Science Inventory

Abstract:

Recent advances in our knowledge of arsenic carcinogenesis include the development of rat or mouse models for all human organs in which inorganic arsenic is known to cause cancer -skin, lung, urinary bladder, liver and kidney. Tumors can be produced from eit...

Dose-Response Relationship between Inorganic Arsenic Exposure and Lung Cancer among Arseniasis Residents with Low Methylation Capacity.

PubMed

Hsu, Kuang-Hung; Tsui, Ke-Hung; Hsu, Ling-I; Chiou, Hung-Yi; Chen, Chien-Jen

2017-05-01

Background: Exposure to inorganic arsenic (InAs) has been documented as a risk factor for lung cancer. This study examined the association between InAs exposure, its metabolism, and lung cancer occurrence. Methods: We followed 1,300 residents from an arseniasis area in Taiwan, determined urinary InAs metabolites, and identified 39 lung cancer cases. Cox proportional hazards model was performed. Results: The results demonstrated that participants with either the primary methylation index [monomethylarsonic acid (MMA)/InAs] or the secondary methylation index [dimethylarsenic acid (DMA)/MMA] lower than their respective median values were at a higher risk of lung cancer (HRs from 3.41 to 4.66) than those with high methylation capacity. The incidence density of lung cancer increased from 79.9/100,000 (year -1 ) to 467.4/100,000 (year -1 ) for residents with low methylation capacity and from 0 to 158.5/100,000 (year -1 ) for residents with high methylation capacity when the arsenic exposure dose increased from 2 to 10 ppb to ≥200 ppb, respectively. The analyses revealed a dose-response relationship between lung cancer occurrence and increasing arsenic concentrations in drinking water as well as cumulative arsenic exposure (monotonic trend test; P < 0.05 and P < 0.05, respectively) among the residents with low methylation capacity. The relationship between arsenic exposure and lung cancer among high methylators was not statistically significant. Conclusions: Hypomethylation responses to InAs exposure may dose dependently increase lung cancer occurrence. Impact: The high-risk characteristics observed among those exposed should be considered in future preventive medicine and research on arsenic carcinogenesis. Cancer Epidemiol Biomarkers Prev; 26(5); 756-61. ©2016 AACR . ©2016 American Association for Cancer Research.

Arsenic Speciation in Blue Mussels (Mytilus edulis) Along a Highly Contaminated Arsenic Gradient

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

Whaley-Martin, K.J.; Koch, I.; Moriarty, M.

2012-11-01

Arsenic is naturally present in marine ecosystems, and these can become contaminated from mining activities, which may be of toxicological concern to organisms that bioaccumulate the metalloid into their tissues. The toxic properties of arsenic are dependent on the chemical form in which it is found (e.g., toxic inorganic arsenicals vs nontoxic arsenobetaine), and two analytical techniques, high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption spectroscopy (XAS), were used in the present study to examine the arsenic species distribution in blue mussels (Mytilus edulis) obtained from an area where there is a strongmore » arsenic concentration gradient as a consequence of mining impacted sediments. A strong positive correlation was observed between the concentration of inorganic arsenic species (arsenic compounds with no As-C bonds) and total arsenic concentrations present in M. edulis tissues (R{sup 2} = 0.983), which could result in significant toxicological consequences to the mussels and higher trophic consumers. However, concentrations of organoarsenicals, dominated by arsenobetaine, remained relatively constant regardless of the increasing As concentration in M. edulis tissue (R{sup 2} = 0.307). XANES bulk analysis and XAS two-dimensional mapping of wet M. edulis tissue revealed the presence of predominantly arsenic-sulfur compounds. The XAS mapping revealed that the As(III)-S and/or As(III) compounds were concentrated in the digestive gland. However, arsenobetaine was found in small and similar concentrations in the digestive gland as well as the surrounding tissue suggesting arsenobetaine may being used in all of the mussel's cells in a physiological function such as an intracellular osmolyte.« less

Integrated Quantitative Cancer Risk Assessment of Inorganic Arsenic

EPA Science Inventory

This paper attempts to make an integrated risk assessment of arsenic, using data on humans exposed to arsenic via inhalation and ingestion. he data useful for making an integrated analysis and data gaps are discussed. rsenic provides a rare opportunity to compare the cancer risk ...

Inorganic arsenic represses interleukin-17A expression in human activated Th17 lymphocytes

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

Morzadec, Claudie; Macoch, Mélinda; Robineau, Marc

2012-08-01

Trivalent inorganic arsenic [As(III)] is an efficient anticancer agent used to treat patients suffering from acute promyelocytic leukemia. Recently, experimental studies have clearly demonstrated that this metalloid can also cure lymphoproliferative and/or pro-inflammatory syndromes in different murine models of chronic immune-mediated diseases. T helper (Th) 1 and Th17 lymphocytes play a central role in development of these diseases, in mice and humans, especially by secreting the potent pro-inflammatory cytokine interferon-γ and IL-17A, respectively. As(III) impairs basic functions of human T cells but its ability to modulate secretion of pro-inflammatory cytokines by differentiated Th lymphocytes is unknown. In the present study,more » we demonstrate that As(III), used at concentrations clinically achievable in plasma of patients, has no effect on the secretion of interferon-γ from Th1 cells but almost totally blocks the expression and the release of IL-17A from human Th17 lymphocytes co-stimulated for five days with anti-CD3 and anti-CD28 antibodies, in the presence of differentiating cytokines. In addition, As(III) specifically reduces mRNA levels of the retinoic-related orphan receptor (ROR)C gene which encodes RORγt, a key transcription factor controlling optimal IL-17 expression in fully differentiated Th17 cells. The metalloid also blocks initial expression of IL-17 gene induced by the co-stimulation, probably in part by impairing activation of the JNK/c-Jun pathway. In conclusion, our results demonstrate that As(III) represses expression of the major pro-inflammatory cytokine IL-17A produced by human Th17 lymphocytes, thus strengthening the idea that As(III) may be useful to treat inflammatory immune-mediated diseases in humans. -- Highlights: ► Arsenic inhibits secretion of IL-17A from human naïve and memory Th17 lymphocytes. ► Arsenic represses early expression of IL-17A gene in human activated T lymphocytes. ► Arsenic interferes with

Chronic arsenic intoxication diagnostic score (CAsIDS).

PubMed

Dani, Sergio Ulhoa; Walter, Gerhard Franz

2018-01-01

Arsenic and its compounds are well-established, potent, environmentally widespread and persistent toxicants with metabolic, genotoxic, mutagenic, teratogenic, epigenetic and carcinogenic effects. Arsenic occurs naturally in the Earth's crust, but anthropogenic arsenic emissions have surmounted the emissions from important natural sources such as volcanism. Inorganic arsenicals exhibit acute and chronic toxicities in virtually all cell types and tissues, and hence arsenic intoxication affects multiple systems. Whereas acute arsenic intoxication is rare and relatively easy to diagnose, chronic arsenic intoxication (CAsI) is common but goes often misdiagnosed. Based on a review of the literature as well as our own clinical experience, we propose a chronic arsenic intoxication diagnostic score (CAsIDS). A distinctive feature of CAsIDS is the use of bone arsenic load as an essential criterion for the individual risk assessment of chronic arsenic intoxication, combined with a systemic clinical assessment. We present clinical examples where CAsIDS is applied for the diagnosis of CAsI, review the main topics of the toxicity of arsenic in different cell and organ systems and discuss the therapy and prevention of disease caused or aggravated by chronic arsenic intoxication. CAsIDS can help physicians establish the diagnosis of CAsI and associated conditions. Copyright © 2017 John Wiley & Sons, Ltd.

DEVELOPMENT OF ARSENIC SPECIATION METHODOLOGY FOR DETERMINING BACKGROUND EXPOSURE LEVELS OF INORGANIC ARSENIC IN DIETARY SAMPLES AND APPLICATION TO IN VITRO BIOACCESSIBILITY STUDIES

EPA Science Inventory

Ingestion of arsenic is the primary route of exposure for most people, with dietary intake and drinking water as the primary sources of that exposure. Traditionally, measurements of arsenic dietary intake are based on food consumption data coupled with total arsenic data from a ...

Simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by 3-(2-aminoethylamino) propyltrimethoxysilane modified multi-wall carbon nanotubes packed microcolumn solid phase extraction and ICP-MS.

PubMed

Peng, Hanyong; Zhang, Nan; He, Man; Chen, Beibei; Hu, Bin

2015-01-01

Speciation analysis of inorganic arsenic, chromium and selenium in environmental waters is of great significance for the monitoring of environmental pollution. In this work, 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) functionalized multi-wall carbon nanotubes (MWCNTs) were synthesized and employed as the adsorbent for simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by microcolumn solid-phase extraction (SPE)-inductively coupled plasma mass spectrometry (ICP-MS). It was found that As(V), Cr(VI) and Se(VI) could be selectively adsorbed on the microcolumn packed with AAPTS-MWCNTs adsorbent at pH around 2.2, while As(III), Cr(III) and Se(IV) could not be retained at this pH and passed through the microcolumn directly. Total inorganic arsenic, chromium and selenium was determined after the oxidation of As(III), Cr(III) and Se(IV) to As(V), Cr(VI) and Se(VI) with 10.0 μmol L(-1) KMnO4. The assay of As(III), Cr(III) and Se(IV) was based on subtracting As(V), Cr(VI) and Se(VI) from the total As, Cr and Se, respectively. Under the optimized conditions, the detection limits of 15, 38 and 16 ng L(-1) with the relative standard deviations (RSDs) of 7.4, 2.4 and 6.2% (c=1 µg L(-1), n=7) were obtained for As(V), Cr(VI) and Se(VI), respectively. The developed method was validated by analyzing four Certified Reference Materials, rainwater, Yangtze River and East Lake waters. Copyright © 2014 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...

Inorganic arsenic contents in ready-to-eat rice products and various Korean rice determined by a highly sensitive gas chromatography-tandem mass spectrometry.

PubMed

Jung, Mun Yhung; Kang, Ju Hee; Jung, Hyun Jeong; Ma, Sang Yong

2018-02-01

Rice and rice products have been reported to contain high contents of toxic inorganic arsenic (iAs). The inorganic arsenic contents in microwavable ready-to-eat rice products (n=30) and different types of Korean rice (n=102) were determined by a gas chromatography-tandem mass spectrometry (GC-MS/MS). The method showed low limit of detection (0.015pg), high intra- and inter-day repeatability (<7.3%, RSD), and recovery rates (90-117%). The mean iAs content in the ready-to-eat rice products was 59μgkg -1 (dry weight basis). The mean iAs contents in polished white, brown, black, and waxy rice were 65, 109, 91, and 66μgkg -1 , respectively. The percentages of ready-to-eat rice products, white, brown, black, and waxy rice containing iAs over the maximum level (100μgkg -1 ) set by EU for the infant foods were 17, 4, 70, 36 and 0%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of inorganic arsenic and its organic metabolites in urine by flow-injection hydride generation atomic absorption spectrometry.

PubMed

Hanna, C P; Tyson, J F; McIntosh, S

1993-08-01

A method has been developed for the determination of inorganic arsenic [As(III) and As(V)] and its organic metabolites (monomethylarsenic and dimethylarsenic) in urine by flow-injection hydride generation atomic absorption spectrometry. The nontoxic seafood-derived arsenobetaine and arsenocholine species were first separated by a solid-phase extraction procedure. The remaining sample was digested with a mixture of nitric and sulfuric acids and potassium dichromate, followed by attack with hydrogen peroxide. The resulting As(V) was reduced to As(III) with potassium iodide in hydrochloric acid before injection into the flow-injection manifold. The percentage analytical recoveries (mean +/- 95% confidence interval) of various arsenic species added to a urine specimen at 250 micrograms/L were 108 +/- 2, 112 +/- 11, 104 +/- 7, and 95 +/- 5 for As(III), As(V), monomethylarsenic, and dimethylarsenic, respectively. For the determination of arsenic in Standard Reference Material 2670 (toxic metals in human urine), results agreed with the certified value (480 +/- 100 micrograms/L). Analyses of samples for the Centre de Toxicologie du Quebec, containing seafood-derived species, demonstrated the viability of the separation procedure. Detection limits were between 0.1 and 0.2 microgram/L in the solution injected into the manifold, and precision at 10 micrograms/L was between 2% and 3% (CV). These preliminary results show that the method might be applicable to determinations of arsenic in a range of clinical urine specimens.

Transplacental exposure to inorganic arsenic at a hepatocarcinogenic dose induces fetal gene expression changes in mice indicative of aberrant estrogen signaling and disrupted steroid metabolism

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

Liu Jie; Xie Yaxiong; Cooper, Ryan

Exposure to inorganic arsenic in utero in C3H mice produces hepatocellular carcinoma in male offspring when they reach adulthood. To help define the molecular events associated with the fetal onset of arsenic hepatocarcinogenesis, pregnant C3H mice were given drinking water containing 0 (control) or 85 ppm arsenic from day 8 to 18 of gestation. At the end of the arsenic exposure period, male fetal livers were removed and RNA isolated for microarray analysis using 22K oligo chips. Arsenic exposure in utero produced significant (p < 0.001) alterations in expression of 187 genes, with approximately 25% of aberrantly expressed genes relatedmore » to either estrogen signaling or steroid metabolism. Real-time RT-PCR on selected genes confirmed these changes. Various genes controlled by estrogen, including X-inactive-specific transcript, anterior gradient-2, trefoil factor-1, CRP-ductin, ghrelin, and small proline-rich protein-2A, were dramatically over-expressed. Estrogen-regulated genes including cytokeratin 1-19 and Cyp2a4 were over-expressed, although Cyp3a25 was suppressed. Several genes involved with steroid metabolism also showed remarkable expression changes, including increased expression of 17{beta}-hydroxysteroid dehydrogenase-7 (HSD17{beta}7; involved in estradiol production) and decreased expression of HSD17{beta}5 (involved in testosterone production). The expression of key genes important in methionine metabolism, such as methionine adenosyltransferase-1a, betaine-homocysteine methyltransferase and thioether S-methyltransferase, were suppressed. Thus, exposure of mouse fetus to inorganic arsenic during a critical period in development significantly alters the expression of various genes encoding estrogen signaling and steroid or methionine metabolism. These alterations could disrupt genetic programming at the very early life stage, which could impact tumor formation much later in adulthood.« less

Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic flourescence spectrometry

USDA-ARS?s Scientific Manuscript database

Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydrid...

Engineering the Soil Bacterium Pseudomonas putida for Arsenic Methylation

PubMed Central

Chen, Jian; Qin, Jie; Zhu, Yong-Guan; de Lorenzo, Víctor

2013-01-01

Accumulation of arsenic has potential health risks through consumption of food. Here, we inserted the arsenite [As(III)] S-adenosylmethionine methyltransferase (ArsM) gene into the chromosome of Pseudomonas putida KT2440. Recombinant bacteria methylate inorganic arsenic into less toxic organoarsenicals. This has the potential for bioremediation of environmental arsenic and reducing arsenic contamination in food. PMID:23645194

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...

Total inorganic arsenic detection in real water samples using anodic stripping voltammetry and a gold-coated diamond thin-film electrode.

PubMed

Song, Yang; Swain, Greg M

2007-06-12

An accurate method for total inorganic arsenic determination in real water samples was developed using differential pulse anodic stripping voltammetry (DPASV) and a Au-coated boron-doped diamond thin-film electrode. Keys to the method are the use of a conducting diamond platform and solid phase extraction for sample preparation. In the method, the As(III) present in the sample is first detected by DPASV. The As(V) present is then reduced to As(III) by reaction with Na2SO3 and this is followed by a second detection of As(III) by DPASV. Interfering metal ions (e.g., Cu(II)) that cause decreased electrode response sensitivity for arsenic in real samples are removed by solid phase extraction as part of the sample preparation. For example, Cu(II) caused a 30% decrease in the As stripping peak current at a solution concentration ratio of 3:1 (Cu(II)/As(III)). This loss was mitigated by passage of the solution through a Chelex 100 cation exchange resin. After passage, only a 5% As stripping current response loss was seen. The effect of organic matter on the Au-coated diamond electrode response for As(III) was also evaluated. Humic acid at a 5 ppm concentration caused only a 9% decrease in the As stripping peak charge for Au-coated diamond. By comparison, a 50% response decrease was observed for Au foil. Clearly, the chemical properties of the diamond surface in the vicinity of the metal deposits inhibit molecular adsorption on at least some of the Au surface. The method provided reproducible and accurate results for total inorganic arsenic in two contaminated water samples provided by the U.S. Bureau of Reclamation. The total inorganic As concentration in the two samples, quantified by the standard addition method, was 23.2+/-2.9 ppb for UV plant influent water and 16.4+/-0.9 ppb for Well 119 water (n=4). These values differed from the specified concentrations by less than 4%.

The studying of washing of arsenic and sulfur from coals having different ranges of arsenic contents

USGS Publications Warehouse

Wang, M.; Song, D.; Zheng, B.; Finkelman, R.B.; ,

2008-01-01

To study the effectiveness of washing in removal of arsenic and sulfur from coals with different ranges of arsenic concentration, coal was divided into three groups on the basis of arsenic content: 0-5.5 mg/kg, 5.5 mg/kg-8.00 mg/kg, and over 8.00 mg/kg. The result shows that the arsenic in coals with higher arsenic content occurs mainly in an inorganic state and can be relatively easily removed. Arsenic removal is very difficult and less complete when the arsenic content is lower than 5.5 mg/kg because most of this arsenic is in an organic state. There is no relationship between washing rate of total sulfur and arsenic content, but the relationship between the washing rate of total sulfur and percent of organic sulfur is very strong. ?? 2008 New York Academy of Sciences.

Blood Pressure, Left Ventricular Geometry, and Systolic Function in Children Exposed to Inorganic Arsenic

PubMed Central

Osorio-Yáñez, Citlalli; Ayllon-Vergara, Julio C.; Arreola-Mendoza, Laura; Aguilar-Madrid, Guadalupe; Hernández-Castellanos, Erika; Sánchez-Peña, Luz C.

2015-01-01

Background: Inorganic arsenic (iAs) is a ubiquitous element present in the groundwater worldwide. Cardiovascular effects related to iAs exposure have been studied extensively in adult populations. Few epidemiological studies have been focused on iAs exposure–related cardiovascular disease in children. Objective: In this study we investigated the association between iAs exposure, blood pressure (BP), and functional and anatomical echocardiographic parameters in children. Methods: A cross-sectional study of 161 children between 3 and 8 years was conducted in Central Mexico. The total concentration of arsenic (As) species in urine (U-tAs) was determined by hydride generation–cryotrapping–atomic absorption spectrometry and lifetime iAs exposure was estimated by multiplying As concentrations measured in drinking water by the duration of water consumption in years (LAsE). BP was measured by standard protocols, and M-mode echocardiographic parameters were determined by ultrasonography. Results: U-tAs concentration and LAsE were significantly associated with diastolic (DBP) and systolic blood pressure (SBP) in multivariable linear regression models: DBP and SBP were 0.013 (95% CI: 0.002, 0.024) and 0.021 (95% CI: 0.004, 0.037) mmHg higher in association with each 1-ng/mL increase in U-tAs (p < 0.025), respectively. Left ventricular mass (LVM) was significantly associated with LAsE [5.5 g higher (95% CI: 0.65, 10.26) in children with LAsE > 620 compared with < 382 μg/L-year; p = 0.03] in an adjusted multivariable model. The systolic function parameters left ventricular ejection fraction (EF) and shortening fraction were 3.67% (95% CI: –7.14, –0.20) and 3.41% (95% CI: –6.44, –0.37) lower, respectively, in children with U-tAs > 70 ng/mL compared with < 35 ng/mL. Conclusion: Early-life exposure to iAs was significantly associated with higher BP and LVM and with lower EF in our study population of Mexican children. Citation: Osorio-Yáñez C, Ayllon-Vergara JC

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.

Metallothionein blocks oxidative DNA damage induced by acute inorganic arsenic exposure

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

Qu, Wei, E-mail: qu@niehs.nih.gov; Waalkes, Michael P.

We studied how protein metallothionein (MT) impacts arsenic-induced oxidative DNA damage (ODD) using cells that poorly express MT (MT-I/II double knockout embryonic cells; called MT-null cells) and wild-type (WT) MT competent cells. Arsenic (as NaAsO{sub 2}) was less cytolethal over 24 h in WT cells (LC{sub 50} = 11.0 ± 1.3 μM; mean ± SEM) than in MT-null cells (LC{sub 50} = 5.6 ± 1.2 μM). ODD was measured by the immuno-spin trapping method. Arsenic (1 or 5 μM; 24 h) induced much less ODD in WT cells (121% and 141% of control, respectively) than in MT-null cells (202% andmore » 260%). In WT cells arsenic caused concentration-dependent increases in MT expression (transcript and protein), and in the metal-responsive transcription factor-1 (MTF-1), which is required to induce the MT gene. In contrast, basal MT levels were not detectable in MT-null cells and unaltered by arsenic exposure. Transfection of MT-I gene into the MT-null cells markedly reduced arsenic-induced ODD levels. The transport genes, Abcc1 and Abcc2 were increased by arsenic in WT cells but either showed no or very limited increases in MT-null cells. Arsenic caused increases in oxidant stress defense genes HO-1 and GSTα2 in both WT and MT-null cells, but to much higher levels in WT cells. WT cells appear more adept at activating metal transport systems and oxidant response genes, although the role of MT in these responses is unclear. Overall, MT protects against arsenic-induced ODD in MT competent cells by potential sequestration of scavenging oxidant radicals and/or arsenic. - Highlights: • Metallothionein blocks arsenic toxicity. • Metallothionein reduces arsenic-induced DNA damage. • Metallothionein may bind arsenic or radicals produced by arsenic.« less

Arsenic geochemistry and human health in South East Asia

PubMed Central

McCarty, Kathleen M.; Hanh, Hoang Thi; Kim, Kyoung-Woong

2011-01-01

Arsenic occurs naturally in many environmental components and enters the human body through several exposure pathways. Natural enrichment of arsenic may result in considerable contamination of soil, water, and air. Arsenic in groundwater can exceed values hundreds of time higher than the concentration recommended for drinking water. Such exposure levels indicate a serious potential health risk to individuals consuming raw groundwater. Human activities that have an impact on the environment may increase the distribution of inorganic arsenic. Abandoned mines are of great concern due to the extremely high arsenic concentrations detected in mine drainage and tailings. Diet, drinking water, air, soil, and occupational exposures are all sources of inorganic arsenic for humans. Interdisciplinary efforts to better characterize the transport of arsenic and reactants that facilitate their release to the environment are important for human health studies. Multi-disciplinary efforts are needed to study diet, infectious disease, genetics, and cultural practices unique to each region to better understand human health risk and to design public health interventions. PMID:21714384

IDENTIFYING CRITICAL CYSTEINE RESIDUES IN ARSENIC (+3 OXIDATION STATE) METHYLTRANSFERASE

EPA Science Inventory

Arsenic (+3 oxidation state) methyltransferase (AS3MT) catalyzes methylation of inorganic arsenic to mono, di, and trimethylated arsenicals. Orthologous AS3MT genes in genomes ranging from simple echinoderm to human predict a protein with five conserved cysteine (C) residues. In ...

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

Groundwater arsenic in Chimaltenango, Guatemala.

PubMed

Lotter, Jason T; Lacey, Steven E; Lopez, Ramon; Socoy Set, Genaro; Khodadoust, Amid P; Erdal, Serap

2014-09-01

In the Municipality of Chimaltenango, Guatemala, we sampled groundwater for total inorganic arsenic. In total, 42 samples were collected from 27 (43.5%) of the 62 wells in the municipality, with sites chosen to achieve spatial representation throughout the municipality. Samples were collected from household faucets used for drinking water, and sent to the USA for analysis. The only site found to have a concentration above the 10 μg/L World Health Organization provisional guideline for arsenic in drinking water was Cerro Alto, where the average concentration was 47.5 μg/L. A health risk assessment based on the arsenic levels found in Cerro Alto showed an increase in noncarcinogenic and carcinogenic risks for residents as a result of consuming groundwater as their primary drinking water source. Using data from the US Geological Survey and our global positioning system data of the sample locations, we found Cerro Alto to be the only site sampled within the tertiary volcanic rock layer, a known source of naturally occurring arsenic. Recommendations were made to reduce the levels of arsenic found in the community's drinking water so that the health risks can be managed.

Arsenic and the Epigenome: Linked by Methylation(SOT)

EPA Science Inventory

Inorganic arsenic (iAs) is an environmental toxicant currently poisoning millions of people worldwide, and chronically-exposed individuals are susceptible to arsenic poisoning, or arsenicosis. In some exposed populations arsenicosis susceptibility is dependent in part on the abil...

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.

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.

THE ROLE OF ARSENIC (+3 OXIDATION STATE) METHYLTRANSFERASE IN ARSENIC METABOLISM

EPA Science Inventory

Arsenic (As) is widely distributed in the environment. Epidemiological studies have linked chronic exposures to inorganic As (iAs) to adverse health effects such as skin lesions, peripheral neuropathy, cardiovascular, hepatic and renal disorders, diabetes mellitus, skin cancer,...

Arsenic: a roadblock to potential animal waste management solutions.

PubMed

Nachman, Keeve E; Graham, Jay P; Price, Lance B; Silbergeld, Ellen K

2005-09-01

The localization and intensification of the poultry industry over the past 50 years have incidentally created a largely ignored environmental management crisis. As a result of these changes in poultry production, concentrated animal feeding operations (CAFOs) produce far more waste than can be managed by land disposal within the regions where it is produced. As a result, alternative waste management practices are currently being implemented, including incineration and pelletization of waste. However, organic arsenicals used in poultry feed are converted to inorganic arsenicals in poultry waste, limiting the feasibility of waste management alternatives. The presence of inorganic arsenic in incinerator ash and pelletized waste sold as fertilizer creates opportunities for population exposures that did not previously exist. The removal of arsenic from animal feed is a critical step toward safe poultry waste management.

Arsenic in freshwater fish in the Chihuahua County water reservoirs (Mexico).

PubMed

Nevárez, Myrna; Moreno, Myriam Verónica; Sosa, Manuel; Bundschuh, Jochen

2011-01-01

Water reservoirs in Chihuahua County, Mexico, are affected by some punctual and non-punctual geogenic and anthropogenic pollution sources; fish are located at the top of the food chain and are good indicators for the ecosystems pollution. The study goal was to: (i) determine arsenic concentration in fish collected from the Chuviscar, Chihuahua, San Marcos and El Rejon water reservoirs; (ii) to assess if the fishes are suitable for human consumption and (iii) link the arsenic contents in fish with those in sediment and water reported in studies made the same year for these water reservoirs. Sampling was done in summer, fall and winter. The highest arsenic concentration in the species varied through the sampling periods: Channel catfish (Ictalurus punctatus) with 0.22 ± 0.15 mg/kg dw in winter and Green sunfish (Lepomis cyanellus) with 2.00 ± 0.15 mg/kg dw in summer in El Rejon water reservoir. A positive correlation of arsenic contents was found through all sampling seasons in fish samples and the samples of sediment and water. The contribution of the weekly intake of inorganic arsenic, based on the consumption of 0.245 kg fish muscles/body weight/week was found lower than the acceptable weekly intake of 0.015 mg/kg/body weight for inorganic arsenic suggested by FAO/WHO.

Contribution of arsenic species in unicellular algae to the cycling of arsenic in marine ecosystems.

PubMed

Duncan, Elliott G; Maher, William A; Foster, Simon D

2015-01-06

This review investigates the arsenic species produced by and found in marine unicellular algae to determine if unicellular algae contribute to the formation of arsenobetaine (AB) in higher marine organisms. A wide variety of arsenic species have been found in marine unicellular algae including inorganic species (mainly arsenate--As(V)), methylated species (mainly dimethylarsenate (DMA)), arsenoribosides (glycerol, phosphate, and sulfate) and metabolites (dimethylarsenoethanol (DMAE)). Subtle differences in arsenic species distributions exist between chlorophyte and heterokontophyte species with As(V) commonly found in water-soluble cell fractions of chlorophyte species, while DMA is more common in heterokontophyte species. Additionally, different arsenoriboside species are found in each phyla with glycerol and phosphate arsenoribosides produced by chlorophytes, whereas glycerol, phosphate, and sulfate arsenoribosides are produced by heterokontophytes, which is similar to existing data for marine macro-algae. Although arsenoribosides are the major arsenic species in many marine unicellular algal species, AB has not been detected in unicellular algae which supports the hypothesis that AB is formed in marine animals via the ingestion and further metabolism of arsenoribosides. The observation of significant DMAE concentrations in some unicellular algal cultures suggests that unicellular algae-based detritus contains arsenic species that can be further metabolized to form AB in higher marine organisms. Future research establishing how environmental variability influences the production of arsenic species by marine unicellular algae and what effect this has on arsenic cycling within marine food webs is essential to clarify the role of these organisms in marine arsenic cycling.

Chronic Arsenic Poisoning Probably Caused by Arsenic-Based Pesticides: Findings from an Investigation Study of a Household

PubMed Central

Li, Yongfang; Ye, Feng; Wang, Anwei; Wang, Da; Yang, Boyi; Zheng, Quanmei; Sun, Guifan; Gao, Xinghua

2016-01-01

In addition to naturally occurring arsenic, man-made arsenic-based compounds are other sources of arsenic exposure. In 2013, our group identified 12 suspected arsenicosis patients in a household (32 living members). Of them, eight members were diagnosed with skin cancer. Interestingly, all of these patients had lived in the household prior to 1989. An investigation revealed that approximately 2 tons of arsenic-based pesticides had been previously placed near a well that had supplied drinking water to the family from 1973 to 1989. The current arsenic level in the well water was 620 μg/L. No other high arsenic wells were found near the family’s residence. Based on these findings, it is possible to infer that the skin lesions exhibited by these family members were caused by long-term exposure to well water contaminated with arsenic-based pesticides. Additionally, biochemical analysis showed that the individuals exposed to arsenic had higher levels of aspartate aminotransferase and γ-glutamyl transpeptidase than those who were not exposed. These findings might indicate the presence of liver dysfunction in the arsenic-exposed individuals. This report elucidates the effects of arsenical compounds on the occurrence of high levels of arsenic in the environment and emphasizes the severe human health impact of arsenic exposure. PMID:26784217

Chronic Arsenic Poisoning Probably Caused by Arsenic-Based Pesticides: Findings from an Investigation Study of a Household.

PubMed

Li, Yongfang; Ye, Feng; Wang, Anwei; Wang, Da; Yang, Boyi; Zheng, Quanmei; Sun, Guifan; Gao, Xinghua

2016-01-16

In addition to naturally occurring arsenic, man-made arsenic-based compounds are other sources of arsenic exposure. In 2013, our group identified 12 suspected arsenicosis patients in a household (32 living members). Of them, eight members were diagnosed with skin cancer. Interestingly, all of these patients had lived in the household prior to 1989. An investigation revealed that approximately 2 tons of arsenic-based pesticides had been previously placed near a well that had supplied drinking water to the family from 1973 to 1989. The current arsenic level in the well water was 620 μg/L. No other high arsenic wells were found near the family's residence. Based on these findings, it is possible to infer that the skin lesions exhibited by these family members were caused by long-term exposure to well water contaminated with arsenic-based pesticides. Additionally, biochemical analysis showed that the individuals exposed to arsenic had higher levels of aspartate aminotransferase and γ-glutamyl transpeptidase than those who were not exposed. These findings might indicate the presence of liver dysfunction in the arsenic-exposed individuals. This report elucidates the effects of arsenical compounds on the occurrence of high levels of arsenic in the environment and emphasizes the severe human health impact of arsenic exposure.

Arsenic uptake in organic rice production systems

USDA-ARS?s Scientific Manuscript database

Arsenic in rice is known to be a problem in some rice-producing countries that have high levels of inorganic arsenic naturally occurring in water resources. However, it was never considered an issue for USA produced rice until international market surveys were published, indicating some USA rice sam...

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

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.

Relation of dietary inorganic arsenic to serum matrix metalloproteinase-9 (MMP-9) at different threshold concentrations of tap water arsenic

PubMed Central

Kurzius-Spencer, Margaret; Harris, Robin B.; Hartz, Vern; Roberge, Jason; Hsu, Chiu-Hsieh; O’Rourke, Mary Kay; Burgess, Jefferey L.

2015-01-01

Arsenic (As) exposure is associated with cancer, lung and cardiovascular disease, yet the mechanisms involved are not clearly understood. Elevated matrix metalloproteinase-9 (MMP-9) levels are also associated with these diseases, as well as with exposure to water As. Our objective was to evaluate the effects of dietary components of inorganic As (iAs) intake on serum MMP-9 concentration at differing levels of tap water As. In a cross-sectional study of 214 adults, dietary iAs intake was estimated from 24-h dietary recall interviews using published iAs residue data; drinking and cooking water As intake from water samples and consumption data. Aggregate iAs intake (food plus water) was associated with elevated serum MMP-9 in mixed model regression, with and without adjustment for covariates. In models stratified by tap water As, aggregate intake was a significant positive predictor of serum MMP-9 in subjects exposed to water As ≤10 μg/l. Inorganic As from food alone was associated with serum MMP-9 in subjects exposed to tap water As ≤3 μg/l. Exposure to iAs from food and water combined, in areas where tap water As concentration is ≤10 μg/l, may contribute to As-induced changes in a biomarker associated with toxicity. PMID:25605447

Assessment of chemical and biological significance of arsenical species in the Maurice River drainage basin (N. J. ). Part II. Partitioning of arsenic into bottom sediments

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

Faust, S.D.; Winka, A.J.; Belton, T.

1987-01-01

A laboratory study was conducted on the partitioning of four arsenical species onto organic and sandy bottom sediments of Union Lake, N.J. Sandy sediments released more arsenic and sorbed less arsenic than the organic sediments. Organic sediments generally sorbed inorganic As species better than organic As species.

Arsenic speciation in arsenic-rich Brazilian soils from gold mining sites under anaerobic incubation

USGS Publications Warehouse

De Mello, J. W. V.; Talbott, J.L.; Scott, J.; Roy, W.R.; Stucki, J.W.

2007-01-01

Background. Arsenic speciation in environmental samples is essential for studying toxicity, mobility and bio-transformation of As in aquatic and terrestrial environments. Although the inorganic species As(III) and As(V) have been considered dominant in soils and sediments, organisms are able to metabolize inorganic forms of arsenic into organo-arsenic compounds. Arsenosugars and methylated As compounds can be found in terrestrial organisms, but they generally occur only as minor constituents. We investigated the dynamics of arsenic species under anaerobic conditions in soils surrounding gold mining areas from Minas Gerais State, Brazil to elucidate the arsenic biogeochemical cycle and water contamination mechanisms. Methods. Surface soil samples were collected at those sites, namely Paracatu Formation, Banded Iron Formation and Riacho dos Machados Sequence, and incubated in CaCl2 2.5 mmol L-1 suspensions under anaerobic conditions for 1, 28, 56 and 112 days. After that, suspensions were centrifuged and supernatants analyzed for soluble As species by IC-ICPMS and HPLC-ICPMS. Results. Easily exchangeable As was mainly arsenite, except when reducible manganese was present. Arsenate was mainly responsible for the increase in soluble arsenic due to the reductive dissolution of either iron or manganese in samples from the Paracatu Formation and Riacho dos Machados Sequence. On the other hand, organic species of As dominated in samples from the Banded Iron Formation during anaerobic incubation. Discussion. Results are contrary to the expectation that, in anaerobic environments, As release due to the reductive dissolution of Fe is followed by As(V) reduction to As(III). The occurrence of organo-arsenic species was also found to be significant to the dynamics of soluble arsenic, mainly in soils from the Banded Iron Formation (BIF), under our experimental conditions. Conclusions. In general, As(V) and organic As were the dominant species in solution, which is surprising

COMPARATIVE TISSUE DISTRIBUTION AND URINARY EXCRETION OF INORGANIC ARSENIC (IAS) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (ASV) AND ARSENITE (ASIII)

EPA Science Inventory

COMPARATIVE TISSUE DISTRIBUTION AND URINARY EXCRETION OF INORGANIC ARSENIC (iAs) AND ITS METHYLATED METABOLITES IN MICE FOLLOWING ORAL ADMINISTRATION OF ARSENATE (AsV) AND ARSENITE (AsIII). E M Kenyon, L M Del Razo and M F Hughes. U.S. EPA, ORD, NHEERL, ETD, PKB, RTP, NC, USA; ...

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.

PROTEOMIC PROFILING OF CULTURED HUMAN BLADDER CELLS AFTER TRIVALENT ARSENIC EXPOSURES

EPA Science Inventory

Chronic exposure to arsenic has been associated with human cancers of the bladder, kidney, lung, liver, and skin. Inorganic arsenic is biotransformed in a stepwise manner via both a reduction and then an oxidative methylation step in which arsenic cycles between +5 and +3 oxidati...

PROTEOMIC PROFILING OF CULTURED HUMAN BLADDER CELLS AFTER TRIVALENT ARSENICAL EXPOSURES

EPA Science Inventory

Chronic exposure to arsenic has been associated with human cancers of the bladder, kidney, lung, liver, and skin. Inorganic arsenic is biotransformed in a stepwise manner via both a reduction and then an oxidative methylation step in which arsenic cycles between +5 and +3 oxidati...

Arsenic in the human food chain, biotransformation and toxicology--Review focusing on seafood arsenic.

PubMed

Molin, Marianne; Ulven, Stine Marie; Meltzer, Helle Margrete; Alexander, Jan

2015-01-01

Fish and seafood are main contributors of arsenic (As) in the diet. The dominating arsenical is the organoarsenical arsenobetaine (AB), found particularly in finfish. Algae, blue mussels and other filter feeders contain less AB, but more arsenosugars and relatively more inorganic arsenic (iAs), whereas fatty fish contain more arsenolipids. Other compounds present in smaller amounts in seafood include trimethylarsine oxide (TMAO), trimethylarsoniopropionate (TMAP), dimethylarsenate (DMA), methylarsenate (MA) and sulfur-containing arsenicals. The toxic and carcinogenic arsenical iAs is biotransformed in humans and excreted in urine as the carcinogens dimethylarsinate (DMA) and methylarsonate (MA), producing reactive intermediates in the process. Less is known about the biotransformation of organoarsenicals, but new insight indicates that bioconversion of arsenosugars and arsenolipids in seafood results in urinary excretion of DMA, possibly also producing reactive trivalent arsenic intermediates. Recent findings also indicate that the pre-systematic metabolism by colon microbiota play an important role for human metabolism of arsenicals. Processing of seafood may also result in transformation of arsenicals. Copyright © 2015 Elsevier GmbH. All rights reserved.

THE CELLULAR METABOLISM AND SYSTEMIC TOXICITY OF ARSENIC

EPA Science Inventory

Abstract

Toxic Consequences of the Metabolism of Arsenic. David J. Thomas, Miroslav Styblo, and Shan Lin. (2001). Toxicol. Appl. Pharmacol. 000, xxx-yyy.
Although it has been known for decades that humans and many other species metabolize inorganic arsenic to methyl ...

Size-fractionation of groundwater arsenic in alluvial aquifers of West Bengal, India: the role of organic and inorganic colloids.

PubMed

Majumder, Santanu; Nath, Bibhash; Sarkar, Simita; Chatterjee, Debashis; Roman-Ross, Gabriela; Hidalgo, Manuela

2014-01-15

Dissolved organic carbon (DOC) and Fe mineral phases are known to influence the mobility of arsenic (As) in groundwater. Arsenic can be associated with colloidal particles containing organic matter and Fe. Currently, no data is available on the dissolved phase/colloidal association of As in groundwater of alluvial aquifers in West Bengal, India. This study investigated the fractional distribution of As (and other metals/metalloids) among the particulate, colloidal and dissolved phases in groundwater to decipher controlling behavior of organic and inorganic colloids on As mobility. The result shows that 83-94% of As remained in the 'truly dissolved' phases (i.e., <0.05 μm size). Strong positive correlation between Fe and As (r(2) between 0.65 and 0.94) is mainly observed in the larger (i.e., >0.05 μm size) colloidal particles, which indicates the close association of As with larger Fe-rich inorganic colloids. In smaller (i.e., <0.05 μm size) colloidal particles strong positive correlation is observed between As and DOC (r(2)=0.85), which highlights the close association of As with smaller organic colloids. As(III) is mainly associated with larger inorganic colloids, whereas, As(V) is associated with smaller organic/organometallic colloids. Scanning Electron Microscopy and Energy Dispersive X-ray spectroscopy confirm the association of As with DOC and Fe mineral phases suggesting the formation of dissolved organo-Fe complexes and colloidal organo-Fe oxide phases. Attenuated total reflectance-Fourier transform infrared spectroscopy further confirms the formation of As-Fe-NOM organometallic colloids, however, a detailed study of these types of colloids in natural waters is necessary to underpin their controlling behavior. © 2013 Elsevier B.V. All rights reserved.

Expression of arsenic resistance genes in the obligate anaerobe Bacteroides vulgatus ATCC 8482, a gut microbiome bacterium

PubMed Central

Li, Jiaojiao; Mandal, Goutam; Rosen, Barry P.

2016-01-01

The response of the obligate anaerobe Bacteroides vulgatus ATCC 8482, a common human gut microbiota, to arsenic was determined. B. vulgatus ATCC 8482 is highly resistant to pentavalent As(V) and methylarsenate (MAs(V)). It is somewhat more sensitive to trivalent inorganic As(III) but 100-fold more sensitive to methylarsenite (MAs(III)) than to As(III). B. vulgatus ATCC 8482 has eight continuous genes in its genome that we demonstrate form an arsenical-inducible transcriptional unit. The first gene of this ars operon, arsR, encodes a putative ArsR As(III)-responsive transcriptional repressor. The next three genes encode proteins of unknown function. The remaining genes, arsDABC, have well-characterized roles in detoxification of inorganic arsenic, but there are no known genes for MAs(III) resistance. Expression of each gene after exposure to trivalent and pentavalent inorganic and methylarsenicals was analyzed. MAs(III) was the most effective inducer. The arsD gene was the most highly expressed of the ars operon genes. These results demonstrate that this anaerobic microbiome bacterium has arsenic-responsive genes that confer resistance to inorganic arsenic and may be responsible for the organism's ability to maintain its prevalence in the gut following dietary exposure to inorganic arsenic. PMID:27040269

SELENIUM MODIFIES THE METABOLISM AND TOXICITY OF ARSENIC IN PRIMARY RAT HEPATOCYTES

EPA Science Inventory

ABSTRACT
Selenium Modifies the Metabolism and Toxicity of Arsenic in Primary Rat Hepatocytes. Miroslav Styblo, David J. Thomas (2000) Toxicol. Appl. Pharmacol.
Arsenic and selenium are metalloids with similar chemical properties and metabolic fates. Inorganic arsenic (iAs...

An Investigation of Bioaccessibility of Arsenic in Rice using IC-ICP-MS

EPA Science Inventory

Arsenic exposure occurs mainly through drinking water and food; therefore, both aspects should be incorporated into any aggregate exposure assessment. Drinking water exposures are predominately inorganic arsenic while dietary exposures are made up of a diverse set of arsenicals w...

EFFECTS OF DIETARY FOLATE ON ARSENIC-INDUCED GENE EXPRESSION IN MICE

EPA Science Inventory

Effects of Dietary Folate on Arsenic-induced Gene Expression in Mice

Arsenic, a drinking water contaminant, is a known carcinogen. Human exposure to inorganic arsenic has been linked to tumors of skin, bladder, lung, and to a lesser extent, kidney and liver. Dietary fola...

Grain Unloading Of Arsenic Species In Rice

EPA Science Inventory

Rice (Oryza sativa) is the staple food for over half the world's population yet may represent a significant dietary source of inorganic arsenic (As), a nonthreshold, class 1 human carcinogen. Rice grain As is dominated by the inorganic species, and the organic species dim...

Arsenic and its compounds in mushrooms: A review.

PubMed

Falandysz, Jerzy; Rizal, Leela M

2016-10-01

The purpose of this article is to review the detail concentration of arsenic in some species of mushrooms as well as organic and inorganic forms of arsenic in the substrates where wild and cultivated edible mushrooms grow. We also briefly review the molecular forms of arsenic in mushrooms. There is still a lack of experimental data from the environment for a variety of species from different habitats and for different levels of geogenic arsenic in soil. This information will be useful for mushrooms consumers, nutritionists, and food regulatory agencies by describing ways to minimize arsenic content in edible mushrooms and arsenic intake from mushroom meals.

Skin cancer and inorganic arsenic: uncertainty-status of risk.

PubMed

Brown, K G; Guo, H R; Kuo, T L; Greene, H L

1997-02-01

The current U.S. EPA standard for inorganic arsenic in drinking water is 50 ppb (microgram/L), dating to the National Interim Primary Drinking Water Regulation of 1976. The current EPA risk analysis predicts an increased lifetime skin cancer risk on the order of 3 or 4 per 1000 from chronic exposure at that concentration. Revision of the standard to only a few ppb, perhaps even less than 1 ppb, may be indicated by the EPA analysis to reduce the lifetime risk to an acceptable level. The cost to water utilities, and ultimately to their consumers, to conform to such a large reduction in the standard could easily reach several billion dollars, so it is particularly important to assess accurately the current risk and the risk reduction that would be achieved by a lower standard. This article addresses the major sources of uncertainty in the EPA analysis with respect to this objective. Specifically, it focuses on uncertainty and variability in the exposure estimates for the landmark study of Tseng and colleagues in Taiwan, analyzed using a reconstruction of the their exposure data. It is concluded that while the available dataset is suitable to establish the hazard of skin cancer, it is too highly summarized for reliable dose-response assessment. A new epidemiologic study is needed, designed for the requirements of dose-response assessment.

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

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.

Volatilization of arsenic from polluted soil by Pseudomonas putida engineered for expression of the arsM Arsenic(III) S-adenosine methyltransferase gene.

PubMed

Chen, Jian; Sun, Guo-Xin; Wang, Xiao-Xue; Lorenzo, Víctor de; Rosen, Barry P; Zhu, Yong-Guan

2014-09-02

Even though arsenic is one of the most widespread environmental carcinogens, methods of remediation are still limited. In this report we demonstrate that a strain of Pseudomonas putida KT2440 endowed with chromosomal expression of the arsM gene encoding the As(III) S-adenosylmethionine (SAM) methyltransfase from Rhodopseudomonas palustris to remove arsenic from contaminated soil. We genetically engineered the P. putida KT2440 with stable expression of an arsM-gfp fusion gene (GE P. putida), which was inserted into the bacterial chromosome. GE P. putida showed high arsenic methylation and volatilization activity. When exposed to 25 μM arsenite or arsenate overnight, most inorganic arsenic was methylated to the less toxic methylated arsenicals methylarsenate (MAs(V)), dimethylarsenate (DMAs(V)) and trimethylarsine oxide (TMAs(V)O). Of total added arsenic, the species were about 62 ± 2.2% DMAs(V), 25 ± 1.4% MAs(V) and 10 ± 1.2% TMAs(V)O. Volatilized arsenicals were trapped, and the predominant species were dimethylarsine (Me2AsH) (21 ± 1.0%) and trimethylarsine (TMAs(III)) (10 ± 1.2%). At later times, more DMAs(V) and volatile species were produced. Volatilization of Me2AsH and TMAs(III) from contaminated soil is thus possible with this genetically engineered bacterium and could be instrumental as an agent for reducing the inorganic arsenic content of soil and agricultural products.

ARSENIC AND THE EPIGENOME: LINKED BY METHYLATION(Thailand)

EPA Science Inventory

Inorganic arsenic (iAs) is an environmental toxicant currently poisoning millions of people worldwide. The most common route of As exposure in humans is through the consumption of drinking water contaminated with iAs from natural, geologic sources. Inorganic As exists in drinking...

Arsenic Speciation of Solvent-Extracted Leachate from New and Weathered CCA-Treated Wood

PubMed Central

KHAN, BERNINE I.; SOLO - GABRIELE, HELENA M.; DUBEY, BRAJESH K.; TOWNSEND, TIMOTHY G.; CAI, YONG

2009-01-01

For the past 60 yr, chromate-copper-arsenate (CCA) has been used to pressure-treat millions of cubic meters of wood in the United States for the construction of many outdoor structures. Leaching of arsenic from these structures is a possible health concern as there exists the potential for soil and groundwater contamination. While previous studies have focused on total arsenic concentrations leaching from CCA-treated wood, information pertaining to the speciation of arsenic leached is limited. Since arsenic toxicity is dependent upon speciation, the objective of this study was to identify and quantify arsenic species leaching from new and weathered CCA-treated wood and CCA-treated wood ash. Solvent-extraction experiments were carried out by subjecting the treated wood and the ash to solvents of varying pH values, solvents defined in the EPA’s Synthetic Precipitation Leaching Procedure (SPLP) and Toxicity Characteristic Leaching Procedure (TCLP), rainwater, deionized water, and seawater. The generated leachates were analyzed for inorganic As(III) and As(V) and the organoarsenic species, monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA), using high-performance liquid chromatography followed by hydride generation and atomic fluorescence spectrometry (HPLC–HG-AFS). Only the inorganic species were detected in any of the wood leachates; no organoarsenic species were found. Inorganic As(V) was the major detectable species leaching from both new and weathered wood. The weathered wood leached relatively more overall arsenic and was attributed to increased inorganic As(III) leaching. The greater presence of As(III) in the weathered wood samples as compared to the new wood samples may be due to natural chemical and biological transformations during the weathering process. CCA-treated wood ash leached more arsenic than unburned wood using the SPLP and TCLP, and ash samples leached more inorganic As(III) than the unburned counterparts. Increased leaching was due

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.

Toenails as a biomarker of inorganic arsenic intake from drinking water and foods.

PubMed

Slotnick, Melissa J; Meliker, Jaymie R; AvRuskin, Gillian A; Ghosh, Debashis; Nriagu, Jerome O

2007-01-15

Toenails were used recently in epidemiological and environmental health studies as a means of assessing exposure to arsenic from drinking water. While positive correlations between toenail and drinking-water arsenic concentrations were reported in the literature, a significant percentage of the variation in toenail arsenic concentration remains unexplained by drinking-water concentration alone. Here, the influence of water consumption at home and work, food intake, and drinking-water concentration on toenail arsenic concentration was investigated using data from a case-control study being conducted in 11 counties of Michigan. The results from 440 controls are presented. Log-transformed drinking-water arsenic concentration at home was a significant predictor (p < .05) of toenail arsenic concentration (R2 = .32). When arsenic intake from consumption of tap water and beverages made from tap water (microg/L arsenic x L/d = microg/d) was used as a predictor variable, the correlation was markedly increased for individuals with >1 microg/L arsenic (R2 = .48). Increased intake of seafood and intake of arsenic from water at work were independently and significantly associated with increased toenail arsenic concentration. However, when added to intake at home, work drinking-water exposure and food intake had little influence on the overall correlation. These results suggest that arsenic exposure from drinking-water consumption is an important determinant of toenail arsenic concentration, and therefore should be considered when validating and applying toenails as a biomarker of arsenic exposure.

Analysis of arsenical metabolites in biological samples.

PubMed

Hernandez-Zavala, Araceli; Drobna, Zuzana; Styblo, Miroslav; Thomas, David J

2009-11-01

Quantitation of iAs and its methylated metabolites in biological samples provides dosimetric information needed to understand dose-response relations. Here, methods are described for separation of inorganic and mono-, di-, and trimethylated arsenicals by thin layer chromatography. This method has been extensively used to track the metabolism of the radionuclide [(73)As] in a variety of in vitro assay systems. In addition, a hydride generation-cryotrapping-gas chromatography-atomic absorption spectrometric method is described for the quantitation of arsenicals in biological samples. This method uses pH-selective hydride generation to differentiate among arsenicals containing trivalent or pentavalent arsenic.

Arsenic mobilization and immobilization in paddy soils

NASA Astrophysics Data System (ADS)

Kappler, A.; Hohmann, C.; Zhu, Y. G.; Morin, G.

2010-05-01

Arsenic is oftentimes of geogenic origin and in many cases bound to iron(III) minerals. Iron(III)-reducing bacteria can harvest energy by coupling the oxidation of organic or inorganic electron donors to the reduction of Fe(III). This process leads either to dissolution of Fe(III)-containing minerals and thus to a release of the arsenic into the environment or to secondary Fe-mineral formation and immobilisation of arsenic. Additionally, aerobic and anaerobic iron(II)-oxidizing bacteria have the potential to co-precipitate or sorb arsenic during iron(II) oxidation at neutral pH that is usually followed by iron(III) mineral precipitation. We are currently investigating arsenic immobilization by Fe(III)-reducing bacteria and arsenic co-precipitation and immobilization by anaerobic iron(II)-oxidizing bacteria in batch, microcosm and rice pot experiments. Co-precipitation batch experiments with pure cultures of nitrate-dependent Fe(II)-oxidizing bacteria are used to quantify the amount of arsenic that can be immobilized during microbial iron mineral precipitation, to identify the minerals formed and to analyze the arsenic binding environment in the precipitates. Microcosm and rice pot experiments are set-up with arsenic-contaminated rice paddy soil. The microorganisms (either the native microbial population or the soil amended with the nitrate-dependent iron(II)-oxidizing Acidovorax sp. strain BoFeN1) are stimulated either with iron(II), nitrate, or oxygen. Dissolved and solid-phase arsenic and iron are quantified. Iron and arsenic speciation and redox state in batch and microcosm experiments are determined by LC-ICP-MS and synchrotron-based methods (EXAFS, XANES).

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

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.

METHYLATED ARSENICIII SPECIES ARE POTENTIAL PROXIMATE OR ULTIMATE GENOTOXIC FORMS OF ARSENIC

EPA Science Inventory

METHYLATED ARSENIC(III) SPECIES ARE POTENTIAL PROXIMATE OR UL TIMA TE GENOTOXIC FORMS OF ARSENIC

Inorganic arsenic (iAs, arsenite and arsenate) has been thought to act as a genotoxicant without reacting directly with DNA; neither iAs nor As(V) methylated metabolites are e...

REPRODUCTIVE AND DEVELOPMENTAL TOXICITY OF ARSENIC IN RODENTS: A REVIEW

EPA Science Inventory

Arsenic is a recognized reproductive toxicant in humans and induces malformations, especially neural tube defects, in laboratory animals. Early studies showed that murine malformations occurred only when a high dose of inorganic arsenic was given by intravenous or intraperitoneal...

Contribution of inorganic arsenic sources to population exposure risk on a regional scale.

PubMed

Chou, Wei-Chun; Chen, Jein-Wen; Liao, Chung-Min

2016-07-01

Chronic exposure to inorganic arsenic (iAs) in the human population is associated with various internal cancers and other adverse outcomes. The purpose of this study was to estimate a population-scale exposure risk attributable to iAs consumptions by linking a stochastic physiological-based pharmacokinetic (PBPK) model and biomonitoring data of iAs in urine. The urinary As concentrations were obtained from a total of 1,043 subjects living in an industrial area of Taiwan. The results showed that the study subjects had an iAs exposure risk of 27 % (the daily iAs intake for 27 % study subjects exceeded the WHO-recommended value, 2.1 μg iAs day(-1) kg(-1) body weight). Moreover, drinking water and cooked rice contributed to the iAs exposure risk by 10 and 41 %, respectively. The predicted risks in the current study were 4.82, 27.21, 34.69, and 64.17 %, respectively, among the mid-range of Mexico, Taiwan (this study), Korea, and Bangladesh reported in the literature. In conclusion, we developed a population-scale-based risk model that covered the broad range of iAS exposure by integrating stochastic PBPK modeling and reverse dosimetry to generate probabilistic distribution of As intake corresponding to urinary As measured from the cohort study. The model can also be updated as new urinary As information becomes available.

In utero and early childhood exposure to arsenic decreases lung function in children

PubMed Central

Recio-Vega, Rogelio; Gonzalez-Cortes, Tania; Olivas-Calderon, Edgar; Lantz, R. Clark; Gandolfi, A. Jay; Gonzalez-De Alba, Cesar

2016-01-01

Background The lung is a target organ for adverse health outcomes following exposure to arsenic. Several studies have reported a high prevalence of respiratory symptoms and diseases in subjects highly exposed to arsenic through drinking water, however, most studies to date has been performed in exposed adults, with little information on respiratory effects in children. The objective of the study was to evaluate the association between urinary levels of arsenic and its metabolites with lung function in children exposed in utero and in early childhood to high arsenic levels through drinking water. Methods A total of 358 healthy children were included in our study. Individual exposure was assessed based on urinary concentration of inorganic arsenic. Lung function was assessed by spirometry. Results Participants were exposed since pregnancy until early childhood to an average water As concentration of 152.13 μg/L. The mean urinary arsenic level registered in the studied subjects was 141.2 μg/L and only 16.7% had a urinary concentration below the national concern level. Forced vital capacity was significantly decreased in the studied population and it was negatively associated with the percent of inorganic arsenic. More than 57% of the subjects had a restrictive spirometric pattern. The urinary As level was higher in those children with restrictive lung patterns when compared with the levels registered in subjects with normal spirometric patterns. Conclusion Exposure to arsenic through drinking water during in utero and early life was associated with a decrease in FVC and with a restrictive spirometric pattern in the children evaluated. PMID:25131850

A Population-based Case–Control Study of Urinary Arsenic Species and Squamous Cell Carcinoma in New Hampshire, USA

PubMed Central

Li, Zhigang; Perry, Ann E.; Spencer, Steven K.; Gandolfi, A. Jay; Karagas, Margaret R.

2013-01-01

Background: Chronic high arsenic exposure is associated with squamous cell carcinoma (SCC) of the skin, and inorganic arsenic (iAs) metabolites may play an important role in this association. However, little is known about the carcinogenicity of arsenic at levels commonly observed in the United States. Objective: We estimated associations between total urinary arsenic and arsenic species and SCC in a U.S. population. Methods: We conducted a population-based case–control SCC study (470 cases, 447 controls) in a U.S. region with moderate arsenic exposure through private well water and diet. We measured urinary iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), and summed these arsenic species (ΣAs). Because seafood contains arsenolipids and arsenosugars that metabolize into DMA through alternate pathways, participants who reported seafood consumption within 2 days before urine collection were excluded from the analyses. Results: In adjusted logistic regression analyses (323 cases, 319 controls), the SCC odds ratio (OR) was 1.37 for each ln-transformed microgram per liter increase in ln-transformed ΣAs concentration [ln(ΣAs)] (95% CI: 1.04, 1.80). Urinary ln(MMA) and ln(DMA) also were positively associated with SCC (OR = 1.34; 95% CI: 1.04, 1.71 and OR = 1.34; 95% CI: 1.03, 1.74, respectively). A similar trend was observed for ln(iAs) (OR = 1.20; 95% CI: 0.97, 1.49). Percent iAs, MMA, and DMA were not associated with SCC. Conclusions: These results suggest that arsenic exposure at levels common in the United States relates to SCC and that arsenic metabolism ability does not modify the association. Citation: Gilbert-Diamond D, Li Z, Perry AE, Spencer SK, Gandolfi AJ, Karagas MR. 2013. A population-based case–control study of urinary arsenic species and squamous cell carcinoma in New Hampshire, USA. Environ Health Perspect 121:1154–1160; http://dx.doi.org/10.1289/ehp.1206178 PMID:23872349

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 ...

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.

A population-based case-control study of urinary arsenic species and squamous cell carcinoma in New Hampshire, USA.

PubMed

Gilbert-Diamond, Diane; Li, Zhigang; Perry, Ann E; Spencer, Steven K; Gandolfi, A Jay; Karagas, Margaret R

2013-10-01

Chronic high arsenic exposure is associated with squamous cell carcinoma (SCC) of the skin, and inorganic arsenic (iAs) metabolites may play an important role in this association. However, little is known about the carcinogenicity of arsenic at levels commonly observed in the United States. We estimated associations between total urinary arsenic and arsenic species and SCC in a U.S. population. We conducted a population-based case-control SCC study (470 cases, 447 controls) in a U.S. region with moderate arsenic exposure through private well water and diet. We measured urinary iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), and summed these arsenic species (ΣAs). Because seafood contains arsenolipids and arsenosugars that metabolize into DMA through alternate pathways, participants who reported seafood consumption within 2 days before urine collection were excluded from the analyses. In adjusted logistic regression analyses (323 cases, 319 controls), the SCC odds ratio (OR) was 1.37 for each ln-transformed microgram per liter increase in ln-transformed ΣAs concentration [ln(ΣAs)] (95% CI: 1.04, 1.80). Urinary ln(MMA) and ln(DMA) also were positively associated with SCC (OR = 1.34; 95% CI: 1.04, 1.71 and OR = 1.34; 95% CI: 1.03, 1.74, respectively). A similar trend was observed for ln(iAs) (OR = 1.20; 95% CI: 0.97, 1.49). Percent iAs, MMA, and DMA were not associated with SCC. These results suggest that arsenic exposure at levels common in the United States relates to SCC and that arsenic metabolism ability does not modify the association.

Urinary 8-hydroxydeoxyguanosine and urothelial carcinoma risk in low arsenic exposure area

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

Chung, C.-J.; Huang, C.-J.; Pu, Y.-S.

2008-01-01

Arsenic is a well-documented human carcinogen and is known to cause oxidative stress in cultured cells and animals. A hospital-based case-control study was conducted to evaluate the relationship among the levels of urinary 8-hydroxydeoxyguanosine (8-OHdG), the arsenic profile, and urothelial carcinoma (UC). Urinary 8-OHdG was measured by using high-sensitivity enzyme-linked immunosorbent assay (ELISA) kits. The urinary species of inorganic arsenic and their metabolites were analyzed by high-performance liquid chromatography (HPLC) and hydride generator-atomic absorption spectrometry (HG-AAS). This study showed that the mean urinary concentration of total arsenics was significantly higher, at 37.67 {+-} 2.98 {mu}g/g creatinine, for UC patients thanmore » for healthy controls of 21.10 {+-} 0.79 {mu}g/g creatinine (p < 0.01). Urinary 8-OHdG levels correlated with urinary total arsenic concentrations (r = 0.19, p < 0.01). There were significantly higher 8-OHdG levels, of 7.48 {+-} 0.97 ng/mg creatinine in UC patients, compared to healthy controls of 5.95 {+-} 0.21 ng/mg creatinine. Furthermore, female UC patients had higher 8-OHdG levels of 9.22 {+-} 0.75 than those of males at 5.76 {+-} 0.25 ng/mg creatinine (p < 0.01). Multiple linear regression analyses revealed that high urinary 8-OHdG levels were associated with increased total arsenic concentrations, inorganic arsenite, monomethylarsonic acid (MMA), and dimethylarsenate (DMA) as well as the primary methylation index (PMI) even after adjusting for age, gender, and UC status. The results suggest that oxidative DNA damage was associated with arsenic exposure, even at low urinary level of arsenic.« less

Volatilization of Arsenic from Polluted Soil by Pseudomonas putida Engineered for Expression of the arsM Arsenic(III) S-Adenosine Methyltransferase Gene

PubMed Central

2015-01-01

Even though arsenic is one of the most widespread environmental carcinogens, methods of remediation are still limited. In this report we demonstrate that a strain of Pseudomonas putida KT2440 endowed with chromosomal expression of the arsM gene encoding the As(III) S-adenosylmethionine (SAM) methyltransfase from Rhodopseudomonas palustris to remove arsenic from contaminated soil. We genetically engineered the P. putida KT2440 with stable expression of an arsM-gfp fusion gene (GE P. putida), which was inserted into the bacterial chromosome. GE P. putida showed high arsenic methylation and volatilization activity. When exposed to 25 μM arsenite or arsenate overnight, most inorganic arsenic was methylated to the less toxic methylated arsenicals methylarsenate (MAs(V)), dimethylarsenate (DMAs(V)) and trimethylarsine oxide (TMAs(V)O). Of total added arsenic, the species were about 62 ± 2.2% DMAs(V), 25 ± 1.4% MAs(V) and 10 ± 1.2% TMAs(V)O. Volatilized arsenicals were trapped, and the predominant species were dimethylarsine (Me2AsH) (21 ± 1.0%) and trimethylarsine (TMAs(III)) (10 ± 1.2%). At later times, more DMAs(V) and volatile species were produced. Volatilization of Me2AsH and TMAs(III) from contaminated soil is thus possible with this genetically engineered bacterium and could be instrumental as an agent for reducing the inorganic arsenic content of soil and agricultural products. PMID:25122054

[Distributions and seasonal variations of total dissolved inorganic arsenic in the estuaries and coastal area of eastern Hainan].

PubMed

Cao, Xiu-Hong; Ren, Jing-Ling; Zhang, Gui-Ling; Zhang, Jin-E; Du, Jin-Zhou; Zhu, De-Di

2012-03-01

The concentrations of total dissolved inorganic arsenic (TDIAs) were measured by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS). Two cruises were carried out in the river, estuary, coastal area and groundwater of eastern Hainan in December 2006 and August 2007. The concentrations of TDIAs in the Wanquan and Wenchang/Wenjiao rivers and their estuaries, coastal area in December 2006 were 4.0-9.4, 1.3-13.3, 13.3-17.3 nmol x L(-1), respectively. The concentrations of TDIAs in the Wanquan and Wenchang/Wenjiao rivers and their estuaries, coastal area in August 2007 were 1.6-15.5, 2.4-15.9, 10.8-17.6 nmol x L(-1), respectively. There was no significantly seasonal variation of TDIAs in the rivers and estuaries during the dry and wet seasons. Compared with other areas in the world, the concentration of TDIAs in the Eastern Hainan remained at pristine levels. TDIAs showed conservatively mixing in the both estuaries. The concentration of TDIAs of groundwater was below detection limit (BDL)-41.7 nmol x L(-1). The submarine groundwater discharge (SGD) to the coastal area was estimated in the drainage basin of Wenchang/Wenjiao river based on the average concentration of TDIAs in the groundwater and SGD water discharge, with the value of 1 153 mol x a(-1). Budget estimation indicated that the SGD discharge is one of the important sources of arsenic in the coastal area.

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 and Environmental Health: State of the Science and ...

EPA Pesticide Factsheets

Background: Exposure to inorganic and organic arsenic compounds is a major public health problem that affects hundreds of millions of people worldwide. Exposure to arsenic is associated with cancer and noncancer effects in nearly every organ in the body, and evidence is mounting for health effects at lower levels of arsenic exposure than previously thought. Building from a tremendous knowledge base with > 1,000 scientific papers published annually with “arsenic” in the title, the question becomes, what questions would best drive future research directions? Objectives: The objective is to discuss emerging issues in arsenic research and identify data gaps across disciplines. Methods: The National Institutes of Health’s National Institute of Environmental Health Sciences Superfund Research Program convened a workshop to identify emerging issues and research needs to address the multi-faceted challenges related to arsenic and environmental health. This review summarizes information captured during the workshop. Discussion: More information about aggregate exposure to arsenic is needed, including the amount and forms of arsenic found in foods. New strategies for mitigating arsenic exposures and related health effects range from engineered filtering systems to phytogenetics and nutritional interventions. Furthermore, integration of omics data with mechanistic and epidemiological data is a key step toward the goal of linking biomarkers of exposure and suscepti

PROTEOMIC PROFILING OF CULTURED HUMAN BLADDER CELLS AFTER TRIVALENT ARSENICAL EXPOSURES (SOT 2008)

EPA Science Inventory

Chronic exposure to arsenic has been associated with human cancers of the bladder, kidney, lung, liver, and skin. Inorganic arsenic is biotransformed in a stepwise manner via both a reduction and then an oxidative methylation step in which arsenic cycles between +5 and +3 oxidati...

SPECIATION OF ARSENIC IN TARGET FOODS AND COMPOSITE DIET SAMPLES

EPA Science Inventory

For the general population, food may surpass drinking water as the major source of ingestion of total elemental arsenic. Accurate assessments of inorganic arsenic intake via food are needed to understand the relative contributions of drinking water and foods to human exposures t...

Presence of arsenic in pet food: a real hazard?

PubMed

Squadrone, Stefania; Brizio, Paola; Simone, Giuseppe; Benedetto, Alessandro; Monaco, Gabriella; Abete, Maria Cesarina

2017-12-29

In this study, arsenic content in 200 cat- and dog-food samples was estimated by means of electro thermal atomic absorption (Z-ETA-AAS), after using the wet digestion method, that were imported or commercialised in Italy from 2007 to 2012. The maximum value of total arsenic (As) in the samples was 12.5 mg kg-1. Some imported pet food was intercepted as a result of the Rapid Alert System for Food and Feed (RASFF) and rejected at the border or withdrawn from the Italian market, because they exceeded the maximum level of arsenic content imposed in Italy at the time of this study (2002/32/EC). All the samples with a signi cant arsenic level were sh-based. Recently, the 2013/1275/EC raised the maximum level of As permitted in sh-based pet food. However, the analysis of As species is required (EFSA 2014) in order to identify correctly the di erent contributions of dietary exposure to inorganic As and to assure pet food quality.

DEVELOPMENT OF A HUMAN PHYSIOLOGICALLY-BASED PHARMACOKINETIC (PBPK) MODEL FOR INORGANIC ARSENIC AND ITS MONO- AND DI-METHYLATED METABOLITES

EPA Science Inventory

A physiologically-based pharmacokinetic (PBPK) model was developed to estimate levels of arsenic and its metabolites in human tissues and urine after oral exposure to either arsenate (As^V) or arsnite (As^III). The model consists of interconnected individual ...

GENE EXPRESSION DOSE-RESPONSE IN THE BLADDERS OF MICE EXPOSED TO ARSENIC IN DRINKING WATER FOR 13 WEEKS

EPA Science Inventory

The association between drinking water exposures to inorganic arsenic and life-threatening tumors in the human is strongest for bladder cancer. To investigate the mode of action for inorganic arsenic carcinogenicity in the bladder, a study was conducted to characterize the dose-r...

Bioaccessibility and excretion of arsenic in Niu Huang Jie Du Pian pills

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

Koch, Iris; Sylvester, Steven; Lai, Vivian W.-M.

2007-08-01

Traditional Chinese medicines (TCMs) often contain significant levels of potentially toxic elements, including arsenic. Niu Huang Jie Du Pian pills were analyzed to determine the concentration, bioaccessibility (arsenic fraction soluble in the human gastrointestinal system) and chemical form (speciation) of arsenic. Arsenic excretion in urine (including speciation) and facial hair were studied after a one-time ingestion. The pills contained arsenic in the form of realgar, and although the total arsenic that was present in a single pill was high (28 mg), the low bioaccessibility of this form of arsenic predicted that only 4% of it was available for absorption intomore » the bloodstream (1 mg of arsenic per pill). The species of arsenic that were solubilized were inorganic arsenate (As(V)) and arsenite (As(III)) but DMAA and MMAA were detected in urine. Two urinary arsenic excretion peaks were observed: an initial peak several (4-8) hours after ingestion corresponding to the excretion of predominantly As(III), and a larger peak at 14 h corresponding predominantly to DMAA and MMAA. No methylated As(III) species were observed. Facial hair analysis revealed that arsenic concentrations did not increase significantly as a result of the ingestion. Arsenic is incompletely soluble under human gastrointestinal conditions, and is metabolized from the inorganic to organic forms found in urine. Bioaccessible arsenic is comparable to the quantity excreted. Facial hair as a bio-indicator should be further tested.« less

Quantification of inorganic arsenic exposure and cancer risk via consumption of vegetables in southern selected districts of Pakistan

PubMed Central

Rehman, Zahir Ur; Khan, Sardar; Qin, Kun; Brusseau, Mark L; Shah, Mohammad Tahir; Din, Islamud

2016-01-01

Human exposures to arsenic (As) through different pathways (dietary and non-dietary) are considered to be one of the primary worldwide environmental health risks to humans. This study was conducted to investigate the presence of As in soil and vegetable samples collected from agricultural lands located in selected southern districts of Khyber Pakhtunkhwa (KPK) Province, Pakistan. We examined the concentrations of total arsenic (TAs), organic species of As such as monomethylarsonic acid (MMA) and dimethylarsonic acid (DMA), and inorganic species including arsenite (AsIII) and arsenate (AsV) in both soil and vegetable. The data were used to determine several parameters to evaluate human health risk, including bioconcentration factor (BCF) from soil to plant, average daily intake (ADI), health risk index (HRI), incremental lifetime cancer risk (ILTCR), and hazard quotient (HQ). The total As concentration in soil samples of the five districts ranged from 3.0-3.9 mg kg−1, exhibiting minimal variations from site to site. The mean As concentration in edible portions of vegetable samples ranged from 0.03-1.38 mg kg−1. It was observed that As concentrations in 75% of the vegetable samples exceeded the safe maximum allowable limit (0.1 mg kg−1) set by WHO/FAO. The highest value of ADI for As was measured for M. charantia, while the lowest was for A. chinense. The results of this study revealed minimal health risk (HI <1) associated with consumption of vegetables for the local inhabitants. The ILTCR values for inorganic As indicated a minimal potential cancer risk through ingestion of vegetables. In addition, the HQ values for total As were <1, indicating minimal non-cancer risk. PMID:26820935

Inorganic Arsenic and Basal Cell Carcinoma in Areas of Hungary, Romania, and Slovakia: A Case–Control Study

PubMed Central

Leonardi, Giovanni; Vahter, Marie; Clemens, Felicity; Goessler, Walter; Gurzau, Eugen; Hemminki, Kari; Hough, Rupert; Koppova, Kvetoslava; Kumar, Rajiv; Rudnai, Peter; Surdu, Simona

2012-01-01

Background: Inorganic arsenic (iAs) is a potent carcinogen, but there is a lack of information about cancer risk for concentrations < 100 μg/L in drinking water. Objectives: We aimed to quantify skin cancer relative risks in relation to iAs exposure < 100 μg/L and the modifying effects of iAs metabolism. Methods: The Arsenic Health Risk Assessment and Molecular Epidemiology (ASHRAM) study, a case–control study, was conducted in areas of Hungary, Romania, and Slovakia with reported presence of iAs in groundwater. Consecutively diagnosed cases of basal cell carcinoma (BCC) of the skin were histologically confirmed; controls were general surgery, orthopedic, and trauma patients who were frequency matched to cases by age, sex, and area of residence. Exposure indices were constructed based on information on iAs intake over the lifetime of participants. iAs metabolism status was classified based on urinary concentrations of methylarsonic acid (MA) and dimethylarsinic acid (DMA). Associations were estimated by multivariable logistic regression. Results: A total of 529 cases with BCC and 540 controls were recruited for the study. BCC was positively associated with three indices of iAs exposure: peak daily iAs dose rate, cumulative iAs dose, and lifetime average water iAs concentration. The adjusted odds ratio per 10-μg/L increase in average lifetime water iAs concentration was 1.18 (95% confidence interval: 1.08, 1.28). The estimated effect of iAs on cancer was stronger in participants with urinary markers indicating incomplete metabolism of iAs: higher percentage of MA in urine or a lower percentage of DMA. Conclusion: We found a positive association between BCC and exposure to iAs through drinking water with concentrations < 100 μg/L. PMID:22436128

Biological and Behavorial Factors Modify Biomarkers of Arsenic Exposure in a U.S. Population**

EPA Science Inventory

Although consumption of drinking water contaminated with inorganic arsenic is usually considered the primary exposure route, aggregate exposure to arsenic depends on direct consumption of water, use of water in food preparation, and the presence in arsenicals in foods. To gain in...

The Association of Arsenic Exposure and Arsenic Metabolism with the Metabolic Syndrome and its Individual Components: Prospective Evidence from the Strong Heart Family Study.

PubMed

Spratlen, Miranda J; Grau-Perez, Maria; Best, Lyle G; Yracheta, Joseph; Lazo, Mariana; Vaidya, Dhananjay; Balakrishnan, Poojitha; Gamble, Mary V; Francesconi, Kevin A; Goessler, Walter; Cole, Shelley A; Umans, Jason G; Howard, Barbara V; Navas-Acien, Ana

2018-03-15

Inorganic arsenic exposure is ubiquitous and both exposure and inter-individual differences in its metabolism have been associated with cardiometabolic risk. The association between arsenic exposure and arsenic metabolism with metabolic syndrome and its individual components, however, is relatively unknown. We used poisson regression with robust variance to evaluate the association between baseline arsenic exposure (urine arsenic levels) and metabolism (relative percentage of arsenic species over their sum) with incident metabolic syndrome and its individual components (elevated waist circumference, elevated triglycerides, reduced HDL, hypertension, elevated fasting plasma glucose) in 1,047 participants from the Strong Heart Family Study, a prospective family-based cohort in American Indian communities (baseline visits in 1998-1999 and 2001-2003, follow-up visits in 2001-2003 and 2006-2009). 32% of participants developed metabolic syndrome over follow-up. An IQR increase in arsenic exposure was associated with 1.19 (95% CI: 1.01, 1.41) greater risk for elevated fasting plasma glucose but not with other individual components or overall metabolic syndrome. Arsenic metabolism, specifically lower MMA% and higher DMA% was associated with higher risk of overall metabolic syndrome and elevated waist circumference, but not with any other component. These findings support there is a contrasting and independent association between arsenic exposure and arsenic metabolism with metabolic outcomes which may contribute to overall diabetes risk.

Nanomaterial-based electrochemical sensors for arsenic - A review.

PubMed

Kempahanumakkagari, Sureshkumar; Deep, Akash; Kim, Ki-Hyun; Kumar Kailasa, Suresh; Yoon, Hye-On

2017-09-15

The existence of arsenic in the environment poses severe global health threats. Considering its toxicity, the sensing of arsenic is extremely important. Due to the complexity of environmental and biological samples, many of the available detection methods for arsenic have serious limitations on selectivity and sensitivity. To improve sensitivity and selectivity and to circumvent interferences, different electrode systems have been developed based on surface modification with nanomaterials including carbonaceous nanomaterials, metallic nanoparticles (MNPs), metal nanotubes (MNTs), and even enzymes. Despite the progress made in electrochemical sensing of arsenic, some issues still need to be addressed to realize cost effective, portable, and flow-injection type sensor systems. The present review provides an in-depth evaluation of the nanoparticle-modified electrode (NME) based methods for the electrochemical sensing of arsenic. NME based sensing systems are projected to become an important option for monitoring hazardous pollutants in both environmental and biological media. Copyright © 2017 Elsevier B.V. All rights reserved.

Organic Arsenicals as Functional Motifs in Polymer and Biomaterials Science.

PubMed

Tanaka, Joji; Davis, Thomas P; Wilson, Paul

2018-05-28

Arsenic (As) exhibits diverse (bio)chemical reactivity and biological activity depending upon its oxidation state. However, this distinctive reactivity has been largely overlooked across many fields owing to concerns regarding the toxicity of arsenic. Recently, a clinical renaissance in the use of arsenicals, including organic arsenicals that are known to be less toxic than inorganic arsenicals, alludes to the possibility of broader acceptance and application in the field of polymer and biomaterials science. Here, current examples of polymeric/macromolecular arsenicals are reported to stimulate interest and highlight their potential as a novel platform for functional, responsive, and bioactive materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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...

MEETING AT CAMBRIDGE, MA: GENE EXPRESSION IN NORMAL HUMAN KERATINOCYTES MODULATED BY TRIVALENT ARSENICALS

EPA Science Inventory

Arsenic exposure has been correlated with the development of several human cancers including those found in the skin, lung, liver, kidney and urinary bladder. Humans are generally exposed to inorganic forms of arsenic, which may be inhaled or ingested. Arsenic forms mono- and d...

Soil calcium significantly promotes uptake of inorganic arsenic by garland chrysanthemum (ChrysanthemumL coronarium) fertilized with chicken manure bearing roxarsone and its metabolites.

PubMed

Yao, Lixian; Huang, Lianxi; Bai, Cuihua; He, Zhaohuan; Zhou, Changmin

2017-07-01

Roxarsone (ROX), a widely used feed organoarsenic additive, occurs as itself and its metabolites in animal manure that is commonly land used as fertilizer. Soil property impacts arsenic (As) speciation and bioavailability. Fourteen soils across China were used to conduct culture experiments to investigate As uptake by garland chrysanthemum (ChrysanthemumL coronarium), with the soils fertilized with chicken manure bearing ROX and its metabolites. The results show As(III) was the sole As form in garland chrysanthemum shoots, and As(III) and As(V) occurred in roots. Only inorganic As was detected in all soils when the plants were harvested. Stepwise regression analysis shows soil-exchangeable Ca predominated shoot As(III) concentration (shoot As(III) = 1.60030 soil Ca, R 2  = 0.8832***). Therefore, ROX is transferred into the human food chain finally as inorganic As in plants. Application of animal manure bearing ROX and its metabolites is not recommended in Ca-rich soils to avoid excess inorganic As dietary exposure.

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...

Proteomic Analysis of Arsenic-Induced Oxidative Stress in Human Epidermal Keratinocytes

EPA Science Inventory

Chronic exposure to inorganic arsenic (IAs) has been associated with the development of several human cancers, including those found in the skin, lung, urinary bladder, liver, prostate and kidney. The precise mechanisms by which arsenic causes cancer are unknown. Defining the mod...

THE ROLE OF FLAVONOIDS IN MODULATION OF THE METABOLISM OF ARSENIC

EPA Science Inventory

The biotransformation of inorganic arsenic (iAs) in humans produces trivalent and pentavalent methylated species. The pattern and extent of iAs conversion is critical for the overall toxicity and adverse health effects associated with arsenic exposure. Our previous work showed a ...

Species Specific Bio-accessibility Estimates of Arsenic in US Consumed Rice

EPA Science Inventory

Inorganic arsenic (iAs) has been classified as a Class I carcinogen by the International Agency for Research on Cancer (IARC). For non-occupationally exposed individuals, the two predominant exposure routes for arsenic are drinking water and diet. Drinking water exposures conta...

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...

Arsenic biotransformation by a cyanobacterium Nostoc sp. PCC 7120.

PubMed

Xue, Xi-Mei; Yan, Yu; Xiong, Chan; Raber, Georg; Francesconi, Kevin; Pan, Ting; Ye, Jun; Zhu, Yong-Guan

2017-09-01

Nostoc sp. PCC 7120 (Nostoc), a typical filamentous cyanobacterium ubiquitous in aquatic system, is recognized as a model organism to study prokaryotic cell differentiation and nitrogen fixation. In this study, Nostoc cells incubated with arsenite (As(III)) for two weeks were extracted with dichloromethane/methanol (DCM/MeOH) and the extract was partitioned between water and DCM. Arsenic species in aqueous and DCM layers were determined using high performance liquid chromatography - inductively coupled plasma mass spectrometer/electrospray tandem mass spectrometry (HPLC-ICPMS/ESIMSMS). In addition to inorganic arsenic (iAs), the aqueous layer also contained monomethylarsonate (MAs(V)), dimethylarsinate (DMAs(V)), and the two arsenosugars, namely a glycerol arsenosugar (Oxo-Gly) and a phosphate arsenosugar (Oxo-PO4). Two major arsenosugar phospholipids (AsSugPL982 and AsSugPL984) were detected in DCM fraction. Arsenic in the growth medium was also investigated by HPLC/ICPMS and shown to be present mainly as the inorganic forms As(III) and As(V) accounting for 29%-38% and 29%-57% of the total arsenic respectively. The total arsenic of methylated arsenic, arsenosugars, and arsenosugar phospholipids in Nostoc cells with increasing As(III) exposure were not markedly different, indicating that the transformation to organoarsenic in Nostoc was not dependent on As(III) concentration in the medium. Our results provide new insights into the role of cyanobacteria in the biogeochemical cycling of arsenic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a simple, sensitive and inexpensive ion-pairing cloud point extraction approach for the determination of trace inorganic arsenic species in spring water, beverage and rice samples by UV-Vis spectrophotometry.

PubMed

Gürkan, Ramazan; Kır, Ufuk; Altunay, Nail

2015-08-01

The determination of inorganic arsenic species in water, beverages and foods become crucial in recent years, because arsenic species are considered carcinogenic and found at high concentrations in the samples. This communication describes a new cloud-point extraction (CPE) method for the determination of low quantity of arsenic species in the samples, purchased from the local market by UV-Visible Spectrophotometer (UV-Vis). The method is based on selective ternary complex of As(V) with acridine orange (AOH(+)) being a versatile fluorescence cationic dye in presence of tartaric acid and polyethylene glycol tert-octylphenyl ether (Triton X-114) at pH 5.0. Under the optimized conditions, a preconcentration factor of 65 and detection limit (3S blank/m) of 1.14 μg L(-1) was obtained from the calibration curve constructed in the range of 4-450 μg L(-1) with a correlation coefficient of 0.9932 for As(V). The method is validated by the analysis of certified reference materials (CRMs). Copyright © 2015 Elsevier Ltd. All rights reserved.

Arsenic behavior in newly drilled wells.

PubMed

Kim, Myoung-Jin; Nriagu, Jerome; Haack, Sheridan

2003-07-01

In the present paper, inorganic arsenic species and chemical parameters in groundwater were determined to investigate the factors related to the distribution of arsenic species and their dissolution from rock into groundwater. For the study, groundwater and core samples were taken at different depths of two newly drilled wells in Huron and Lapeer Counties, Michigan. Results show that total arsenic concentrations in the core samples varied, ranging from 0.8 to 70.7 mg/kg. Iron concentration in rock was about 1800 times higher than that of arsenic, and there was no correlation between arsenic and iron occurrences in the rock samples. Arsenic concentrations in groundwater ranged from <1 to 171 microg/l. The arsenic concentration in groundwater depended on the amount of arsenic in aquifer rocks, and as well decreased with increasing depth. Over 90% of arsenic existed in the form of As(III), implying that the groundwater systems were in the reduced condition. The results such as high ferrous ion, low redox potential and low dissolved oxygen supported the observed arsenic species distribution. There was no noticeable difference in the total arsenic concentration and arsenic species ratio between unfiltered and filtered (0.45 microm) waters, indicating that the particulate form of arsenic was negligible in the groundwater samples. There were correlations between water sampling depth and chemical parameters, and between arsenic concentration and chemical parameters, however, the trends were not always consistent in both wells.

Both Phosphorus Fertilizers and Indigenous Bacteria Enhance Arsenic Release into Groundwater in Arsenic-Contaminated Aquifers.

PubMed

Lin, Tzu-Yu; Wei, Chia-Cheng; Huang, Chi-Wei; Chang, Chun-Han; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

2016-03-23

Arsenic (As) is a human carcinogen, and arsenic contamination in groundwater is a worldwide public health concern. Arsenic-affected areas are found in many places but are reported mostly in agricultural farmlands, yet the interaction of fertilizers, microorganisms, and arsenic mobilization in arsenic-contaminated aquifers remains uncharacterized. This study investigates the effects of fertilizers and bacteria on the mobilization of arsenic in two arsenic-contaminated aquifers. We performed microcosm experiments using arsenic-contaminated sediments and amended with inorganic nitrogenous or phosphorus fertilizers for 1 and 4 months under aerobic and anaerobic conditions. The results show that microcosms amended with 100 mg/L phosphorus fertilizers (dipotassium phosphate), but not nitrogenous fertilizers (ammonium sulfate), significantly increase aqueous As(III) release in arsenic-contaminated sediments under anaerobic condition. We also show that concentrations of iron, manganese, potassium, sodium, calcium, and magnesium are increased in the aqueous phase and that the addition of dipotassium phosphate causes a further increase in aqueous iron, potassium, and sodium, suggesting that multiple metal elements may take part in the arsenic release process. Furthermore, microbial analysis indicates that the dominant microbial phylum is shifted from α-proteobacteria to β- and γ-proteobacteria when the As(III) is increased and phosphate is added in the aquifer. Our results provide evidence that both phosphorus fertilizers and microorganisms can mediate the release of arsenic to groundwater in arsenic-contaminated sediments under anaerobic condition. Our study suggests that agricultural activity such as the use of fertilizers and monitoring phosphate concentration in groundwater should be taken into consideration for the management of arsenic in groundwater.

Investigation of Health Effects According to the Exposure of Low Concentration Arsenic Contaminated Ground Water

PubMed Central

Hong, Young-seoub; Ye, Byeong-jin; Kim, Yu-mi; Kim, Byoung-gwon; Kang, Gyeong-hui; Kim, Jeong-jin; Song, Ki-hoon; Kim, Young-hun

2017-01-01

Recent epidemiological studies have reported adverse health effects, including skin cancer, due to low concentrations of arsenic via drinking water. We conducted a study to assess whether low arsenic contaminated ground water affected health of the residents who consumed it. For precise biomonitoring results, the inorganic (trivalent arsenite (As III) and pentavalent arsenate (As V)) and organic forms (monomethylarsonate (MMA) and dimethylarsinate (DMA)) of arsenic were separately quantified by combining high-performance liquid chromatography and inductively coupled plasma mass spectroscopy from urine samples. In conclusion, urinary As III, As V, MMA, and hair arsenic concentrations were significantly higher in residents who consumed arsenic contaminated ground water than control participants who consumed tap water. But, most health screening results did not show a statistically significant difference between exposed and control subjects. We presume that the elevated arsenic concentrations may not be sufficient to cause detectable health effects. Consumption of arsenic contaminated ground water could result in elevated urinary organic and inorganic arsenic concentrations. We recommend immediate discontinuation of ground water supply in this area for the safety of the residents. PMID:29186890

Inorganic arsenic causes fatty liver and interacts with ethanol to cause alcoholic liver disease in zebrafish

PubMed Central

Zhang, Chi; Austin, Christine; Amarasiriwardena, Chitra; Arora, Manish

2018-01-01

ABSTRACT The rapid increase in fatty liver disease (FLD) incidence is attributed largely to genetic and lifestyle factors; however, environmental toxicants are a frequently overlooked factor that can modify the effects of more common causes of FLD. Chronic exposure to inorganic arsenic (iAs) is associated with liver disease in humans and animal models, but neither the mechanism of action nor the combinatorial interaction with other disease-causing factors has been fully investigated. Here, we examined the contribution of iAs to FLD using zebrafish and tested the interaction with ethanol to cause alcoholic liver disease (ALD). We report that zebrafish exposed to iAs throughout development developed specific phenotypes beginning at 4 days post-fertilization (dpf), including the development of FLD in over 50% of larvae by 5 dpf. Comparative transcriptomic analysis of livers from larvae exposed to either iAs or ethanol revealed the oxidative stress response and the unfolded protein response (UPR) caused by endoplasmic reticulum (ER) stress as common pathways in both these models of FLD, suggesting that they target similar cellular processes. This was confirmed by our finding that arsenic is synthetically lethal with both ethanol and a well-characterized ER-stress-inducing agent (tunicamycin), suggesting that these exposures work together through UPR activation to cause iAs toxicity. Most significantly, combined exposure to sub-toxic concentrations of iAs and ethanol potentiated the expression of UPR-associated genes, cooperated to induce FLD, reduced the expression of as3mt, which encodes an arsenic-metabolizing enzyme, and significantly increased the concentration of iAs in the liver. This demonstrates that iAs exposure is sufficient to cause FLD and that low doses of iAs can potentiate the effects of ethanol to cause liver disease. This article has an associated First Person interview with the first author of the paper. PMID:29361514

Titanium dioxide nanoparticles enhance inorganic arsenic bioavailability and methylation in two freshwater algae species.

PubMed

Luo, Zhuanxi; Wang, Zhenhong; Yan, Yameng; Li, Jinli; Yan, Changzhou; Xing, Baoshan

2018-07-01

The effect of titanium dioxide nanoparticles (nano-TiO 2 ) on the bioaccumulation and biotransformation of arsenic (As) remains largely unknown. In this study, we exposed two freshwater algae (Microcystis aeruginosa and Scenedesmus obliquus) to inorganic As (arsenite and arsenate) with the aim of increasing our understanding on As bioaccumulation and methylation in the presence of nano-TiO 2 . Direct evidence from transmission electron microscope (TEM) images show that nano-TiO 2 (anatase) entered exposed algae. Thus, nano-TiO 2 as carriers boosted As accumulation and methylation in these two algae species, which varied between inorganic As speciation and algae species. Specifically, nano-TiO 2 could markedly enhance arsenate (As(V)) accumulation in M. aeruginosa and arsenite (As(III)) accumulation in S. obliquus. Similarly, we found evidence of higher As methylation activity in the M. aeruginosa of As(III) 2 mg L -1 nano-TiO 2 treatment. Although this was also true for the S. obliquus (As(V)) treatment, this species exhibited higher As methylation compared to M. aeruginosa, being more sensitive to As associated with nano-TiO 2 compared to M. aeruginosa. Due to changes in pH levels inside these exposed algae, As dissociation from nano-TiO 2 inside algal cells enhanced As methylation. Accordingly, the potential influence of nanoparticles on the bioaccumulation and biotransformation of their co-contaminants deserves more attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

Determination of inorganic arsenic species in natural waters--benefits of separation and preconcentration on ion exchange and hybrid resins.

PubMed

Ben Issa, Nureddin; Rajaković-Ognjanović, Vladana N; Jovanović, Branislava M; Rajaković, Ljubinka V

2010-07-19

A simple method for the separation and determination of inorganic arsenic (iAs) species in natural and drinking water was developed. Procedures for sample preparation, separation of As(III) and As(V) species and preconcentration of the total iAs on fixed bed columns were defined. Two resins, a strong base anion exchange (SBAE) resin and a hybrid (HY) resin were utilized. The inductively-coupled plasma-mass spectrometry method was applied as the analytical method for the determination of the arsenic concentration in water. The governing factors for the ion exchange/sorption of arsenic on resins in a batch and a fixed bed flow system were analyzed and compared. Acidity of the water, which plays an important role in the control of the ionic or molecular forms of arsenic species, was beneficial for the separation; by adjusting the pH values to less than 8.00, the SBAE resin separated As(V) from As(III) in water by retaining As(V) and allowing As(III) to pass through. The sorption activity of the hydrated iron oxide particles integrated into the HY resin was beneficial for bonding of all iAs species over a wide range of pH values from 5.00 to 11.00. The resin capacities were calculated according to the breakthrough points in a fixed bed flow system. At pH 7.50, the SBAE resin bound more than 370 microg g(-1) of As(V) while the HY resin bound more than 4150 microg g(-1) of As(III) and more than 3500 microg g(-1) of As(V). The high capacities and selectivity of the resins were considered as advantageous for the development and application of two procedures, one for the separation and determination of As(III) (with SBAE) and the other for the preconcentration and determination of the total arsenic (with HY resin). Methods were established through basic analytical procedures (with external standards, certified reference materials and the standard addition method) and by the parallel analysis of some samples using the atomic absorption spectrometry-hydride generation

Human arsenic poisoning issues in central-east Indian locations: biomarkers and biochemical monitoring.

PubMed

Pandey, Piyush Kant; Yadav, Sushma; Pandey, Madhurima

2007-03-01

The study reports the use of three biomarkers i.e. total arsenic in hair and nails, total arsenic in blood, and total arsenic in urine to identify or quantify arsenic exposure and concomitant health effects. The main source of arsenic was inorganic exposure through drinking water. The arsenic levels and the health effects were analyzed closely in a family having maximum symptoms of arsenic. Based on the result of this study it is reported that there exist a correlation between the clinically observable symptoms, the blood and urine arsenic level, and the arsenic intake through drinking water. An intensive study on the urinary arsenic levels was carried out in which the urine levels of arsenic and the urine sufficiency tests were performed. A composite picture of body burden of arsenic has been obtained by carrying out a complete biochemical analysis of a maximum affected family. This confirms pronounced chronic exposure of the arsenic to these people. A combined correlation study on the arsenic levels measured in whole blood, urine, hair, nails and age present a remarkable outcome. Accordingly, the arsenic levels in blood are negatively correlated with the urine arsenic levels, which indicate either the inadequacy of the renal system in cleaning the blood arsenic or a continuous recirculation of the accumulated arsenic. This is an important conclusion about arsenical metabolism in humans. The study also raises the issues of the prospects of complete elimination of the accumulated arsenic and the reversibility of the health effects. Based on the work in Kourikasa village we report that there are very remote chances of complete purging of arsenic and thus reversibility of the health effects owing to various factors. The paper also discusses the various issues concerning the chronic arsenic poisoning management in the affected locations.

COMPREHENSIVE ANALYSIS OF BIOLOGICALLY RELEVANT ARSENICALS BY PH-SELECTIVE HYDRIDE GENERATION-ATOMIC ABSORPTION SPECTROMETRY

EPA Science Inventory

A method based on pH-selective generation and separation of arsines is commonly used for analysis of inorganic, methylated, and dimethylated trivalent and pentavalent arsenicals by hydride generation-atomic absorption spectrometry (HG-AAS). We have optimized this method to pe...

MEETING AT SAN DIEGO, CA: GENE EXPRESSION IN NORMAL HUMAN KERATINOCYTES MODULATED BY TRIVALENT ARSENICALS

EPA Science Inventory

Arsenic exposure has been correlated with the development of several human cancers including those found in the skin, lung, liver, kidney and urinary bladder. Humans are generally exposed to inorganic forms of arsenic, which may be inhaled or ingested. Arsenic forms mono- and di-...

Quantification of inorganic arsenic exposure and cancer risk via consumption of vegetables in southern selected districts of Pakistan.

PubMed

Rehman, Zahir Ur; Khan, Sardar; Qin, Kun; Brusseau, Mark L; Shah, Mohammad Tahir; Din, Islamud

2016-04-15

Human exposures to arsenic (As) through different pathways (dietary and non-dietary) are considered to be one of the primary worldwide environmental health risks to humans. This study was conducted to investigate the presence of As in soil and vegetable samples collected from agricultural lands located in selected southern districts of Khyber Pakhtunkhwa (KPK) Province, Pakistan. We examined the concentrations of total arsenic (TAs), organic species of As such as monomethylarsonic acid (MMA) and dimethylarsonic acid (DMA), and inorganic species including arsenite (AsIII) and arsenate (AsV) in both soil and vegetables. The data were used to determine several parameters to evaluate human health risk, including bioconcentration factor (BCF) from soil to plant, average daily intake (ADI), health risk index (HRI), incremental lifetime cancer risk (ILTCR), and hazard quotient (HQ). The total As concentration in soil samples of the five districts ranged from 3.0-3.9mgkg(-1), exhibiting minimal variations from site to site. The mean As concentration in edible portions of vegetable samples ranged from 0.03-1.38mgkg(-1). It was observed that As concentrations in 75% of the vegetable samples exceeded the safe maximum allowable limit (0.1mgkg(-1)) set by WHO/FAO. The highest value of ADI for As was measured for Momordica charantia, while the lowest was for Allium chinense. The results of this study revealed minimal health risk (HI<1) associated with consumption of vegetables for the local inhabitants. The ILTCR values for inorganic As indicated a minimal potential cancer risk through ingestion of vegetables. In addition, the HQ values for total As were <1, indicating minimal non-cancer risk. Copyright © 2016 Elsevier B.V. All rights reserved.

Chronic arsenic exposure and risk of carotid artery disease: The Strong Heart Study.

PubMed

Mateen, Farrah J; Grau-Perez, Maria; Pollak, Jonathan S; Moon, Katherine A; Howard, Barbara V; Umans, Jason G; Best, Lyle G; Francesconi, Kevin A; Goessler, Walter; Crainiceanu, Ciprian; Guallar, Eliseo; Devereux, Richard B; Roman, Mary J; Navas-Acien, Ana

2017-08-01

Inorganic arsenic exposure from naturally contaminated groundwater is related to vascular disease. No prospective studies have evaluated the association between arsenic and carotid atherosclerosis at low-moderate levels. We examined the association of long-term, low-moderate inorganic arsenic exposure with carotid arterial disease. American Indians, 45-74 years old, in Arizona, Oklahoma, and North and South Dakota had arsenic concentrations (sum of inorganic and methylated species, μg/g urine creatinine) measured from baseline urine samples (1989-1991). Carotid artery ultrasound was performed in 1998-1999. Vascular disease was assessed by the carotid intima media thickness (CIMT), the presence of atherosclerotic plaque in the carotid, and by the number of segments containing plaque (plaque score). 2402 participants (mean age 55.3 years, 63.1% female, mean body mass index 31.0kg/m 2 , diabetes 45.7%, hypertension 34.2%) had a median (interquintile range) urine arsenic concentration of 9.2 (5.00, 17.06) µg/g creatinine. The mean CIMT was 0.75mm. 64.7% had carotid artery plaque (3% with >50% stenosis). In fully adjusted models comparing participants in the 80th vs. 20th percentile in arsenic concentrations, the mean difference in CIMT was 0.01 (95% confidence interval (95%CI): 0.00, 0.02) mm, the relative risk of plaque presence was 1.04 (95%CI: 0.99, 1.09), and the geometric mean ratio of plaque score was 1.05 (95%CI: 1.01, 1.09). Urine arsenic was positively associated with CIMT and increased plaque score later in life although the association was small. The relationship between urinary arsenic and the presence of plaque was not statistically significant when adjusted for other risk factors. Arsenic exposure may play a role in increasing the severity of carotid vascular disease. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

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).

Determination of arsenic species in edible periwinkles (Littorina littorea) by HPLC-ICPMS and XAS along a contamination gradient

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

Whaley-Martin, K. J.; Koch, I.; Reimer, K. J.

Arsenic is naturally found in the tissues of marine animals, usually as the non-toxic arsenical arsenobetaine, but exposure to elevated arsenic concentrations in the environment may alter the arsenic species distribution within tissues of the organism. This study examined the arsenic species in the tissues of the marine periwinkle (Littorina littorea) along an arsenic concentration gradient in the sediment. The arsenicals in L. littorea were examined using the complementary analytical methods high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC–ICPMS) and X-ray absorption spectroscopy (XAS). Total arsenic concentrations in the periwinkle tissues ranged from 56 to 840more » mg · kg -1 dry weight (equivalent to 13 to 190 mg · kg -1 wet weight). Inorganic arsenicals were found to be positively correlated with total arsenic concentrations (R 2 = 0.993) and reached 600 mg · kg -1 dry weight, the highest reported to date in marine organisms. These high inorganic arsenic concentrations within this low trophic organism pose a potential toxicological risk to higher trophic consumers.« less

IN-FIELD PRESERVATION OF ARSENIC SPECIES IN DRINKING WATER USING EDTA

EPA Science Inventory

The two predominant inorganic arsenic species found in drinking waters are As(III) and As(V). As(III) is commonly associated with ground waters while As(V) is associated with surface waters. The efficiency of arsenic removal from a drinking water supply is dependent on the oxid...

THE ROLE OF MEMBRANE TRANSPORTERS IN THE CELLULAR METABOLISM OF ARSENIC

EPA Science Inventory

Arsenic (+3 oxidation state) methyltransferase (AS3MT) catalyzes methylation of inorganic arsenic (iAs) in humans. In this pathway iAs is converted to mono- (MAs) and dimethylated (DMAs) metabolites containing either As^III or As^V. Because toxicities and meta...

Arsenic and Environmental Health: State of the Science and Future Research Opportunities

EPA Science Inventory

Background: Exposure to inorganic and organic arsenic compounds is a major public health problem that affects hundreds of millions of people worldwide. Exposure to arsenic is associated with cancer and noncancer effects in nearly every organ in the body, and evidence is mounting ...

Glutathione Modulates Recominant Rat Arsenic (+3 Oxidation State) Methyltransferase-Catalyzed Formation of Trimethylarsine Oxide and Trimethylarsine

EPA Science Inventory

Humans and other species enzymatically convert inorganic arsenic (iAs) into methylated metabolites. Although the major metabolites are mono- and dimethylated arsenicals, trimethylated arsenicals have been detected in urine following exposure to iAs. The AS3MT gene encodes an ars...

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...

EXCRETION OF ARSENIC IN URINE AS A FUNCTION OF EXPOSURE TO ARSENIC IN DRINKING WATER

EPA Science Inventory

Urinary arsenic (As) concentrations were evaluated as a biomarker of exposure in a U.S. population chronically exposed to inorganic As (InAs) in their drinking water. Ninety-six individuals who consumed drinking water with As concentrations of 8-620 microg/L provided first mornin...

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.

Arsenic Exposure and Toxicology: A Historical Perspective

PubMed Central

Hughes, Michael F.; Beck, Barbara D.; Chen, Yu; Lewis, Ari S.; Thomas, David J.

2011-01-01

The metalloid arsenic is a natural environmental contaminant to which humans are routinely exposed in food, water, air, and soil. Arsenic has a long history of use as a homicidal agent, but in the past 100 years arsenic, has been used as a pesticide, a chemotherapeutic agent and a constituent of consumer products. In some areas of the world, high levels of arsenic are naturally present in drinking water and are a toxicological concern. There are several structural forms and oxidation states of arsenic because it forms alloys with metals and covalent bonds with hydrogen, oxygen, carbon, and other elements. Environmentally relevant forms of arsenic are inorganic and organic existing in the trivalent or pentavalent state. Metabolism of arsenic, catalyzed by arsenic (+3 oxidation state) methyltransferase, is a sequential process of reduction from pentavalency to trivalency followed by oxidative methylation back to pentavalency. Trivalent arsenic is generally more toxicologically potent than pentavalent arsenic. Acute effects of arsenic range from gastrointestinal distress to death. Depending on the dose, chronic arsenic exposure may affect several major organ systems. A major concern of ingested arsenic is cancer, primarily of skin, bladder, and lung. The mode of action of arsenic for its disease endpoints is currently under study. Two key areas are the interaction of trivalent arsenicals with sulfur in proteins and the ability of arsenic to generate oxidative stress. With advances in technology and the recent development of animal models for arsenic carcinogenicity, understanding of the toxicology of arsenic will continue to improve. PMID:21750349

Speciation of the Bioaccessible Fraction of Arsenic in Rice using IC-ICP-MS

EPA Science Inventory

Dietary arsenic exposure occurs mainly through drinking water and food; therefore, both aspects should be incorporated into any aggregate exposure assessment. Drinking water exposures are predominantly inorganic arsenic (AsIng) while dietary exposures are made up of a diverse se...

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.

Application of ICP-MS and HPLC-ICP-MS for diagnosis and therapy of a severe intoxication with hexavalent chromium and inorganic arsenic.

PubMed

Heitland, Peter; Blohm, Martin; Breuer, Christian; Brinkert, Florian; Achilles, Eike Gert; Pukite, Ieva; Köster, Helmut Dietrich

2017-05-01

ICP-MS and HPLC-ICP-MS were applied for diagnosis and therapeutic monitoring in a severe intoxication with a liquid containing hexavalent chromium (Cr(VI)) and inorganic arsenic (iAs). In this rare case a liver transplantation of was considered as the only chance of survival. We developed and applied methods for the determination of Cr(VI) in erythrocytes and total chromium (Cr) and arsenic (As) in blood, plasma, urine and liver tissue by ICP-MS. Exposure to iAs was diagnosed by determination of iAs species and their metabolites in urine by anion exchange HPLC-ICP-MS. Three days after ingestion of the liquid the total Cr concentrations were 2180 and 1070μg/L in whole blood and plasma, respectively, and 4540μg/L Cr(VI) in erythrocytes. The arsenic concentration in blood was 206μg/L. The urinary As species concentrations were <0.5, 109, 115, 154 and 126μg/L for arsenobetaine, As(III), As(V), methylarsonate (V) and dimethylarsinate (V), respectively. Total Cr and As concentrations in the explanted liver were 11.7 and 0.9mg/kg, respectively. Further analytical results of this case study are tabulated and provide valuable data for physicians and toxicologists. Copyright © 2017. Published by Elsevier GmbH.

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.

Evaluation of Exposure to Arsenic in Residential Soil

PubMed Central

Tsuji, Joyce S.; Van Kerkhove, Maria D.; Kaetzel, Rhonda S.; Scrafford, Carolyn G.; Mink, Pamela J.; Barraj, Leila M.; Crecelius, Eric A.; Goodman, Michael

2005-01-01

In response to concerns regarding arsenic in soil from a pesticide manufacturing plant, we conducted a biomonitoring study on children younger than 7 years of age, the age category of children most exposed to soil. Urine samples from 77 children (47% participation rate) were analyzed for total arsenic and arsenic species related to ingestion of inorganic arsenic. Older individuals also provided urine (n = 362) and toenail (n = 67) samples. Speciated urinary arsenic levels were similar between children (geometric mean, geometric SD, and range: 4.0, 2.2, and 0.89–17.7 μg/L, respectively) and older participants (3.8, 1.9, 0.91–19.9 μg/L) and consistent with unexposed populations. Toenail samples were < 1 mg/kg. Correlations between speciated urinary arsenic and arsenic in soil (r = 0.137, p = 0.39; n = 41) or house dust (r = 0.049, p = 0.73; n = 52) were not significant for children. Similarly, questionnaire responses indicating soil exposure were not associated with increased urinary arsenic levels. Relatively low soil arsenic exposure likely precluded quantification of arsenic exposure above background. PMID:16330356

Association Between Variants in Arsenic (+3 Oxidation State) Methyltranserase (AS3MT) and Urinary Metabolites of Inorganic Arsenic: Role of Exposure Level

PubMed Central

Xu, Xiaofan; Drobná, Zuzana; Voruganti, V. Saroja; Barron, Keri; González-Horta, Carmen; Sánchez-Ramírez, Blanca; Ballinas-Casarrubias, Lourdes; Cerón, Roberto Hernández; Morales, Damián Viniegra; Terrazas, Francisco A. Baeza; Ishida, María C.; Gutiérrez-Torres, Daniela S.; Saunders, R. Jesse; Crandell, Jamie; Fry, Rebecca C.; Loomis, Dana; García-Vargas, Gonzalo G.; Del Razo, Luz M.; Stýblo, Miroslav; Mendez, Michelle A.

2016-01-01

Abstract Variants in AS3MT, the gene encoding arsenic (+3 oxidation state) methyltranserase, have been shown to influence patterns of inorganic arsenic (iAs) metabolism. Several studies have suggested that capacity to metabolize iAs may vary depending on levels of iAs exposure. However, it is not known whether the influence of variants in AS3MT on iAs metabolism also vary by level of exposure. We investigated, in a population of Mexican adults exposed to drinking water As, whether associations between 7 candidate variants in AS3MT and urinary iAs metabolites were consistent with prior studies, and whether these associations varied depending on the level of exposure. Overall, associations between urinary iAs metabolites and AS3MT variants were consistent with the literature. Referent genotypes, defined as the genotype previously associated with a higher percentage of urinary dimethylated As (DMAs%), were associated with significant increases in the DMAs% and ratio of DMAs to monomethylated As (MAs), and significant reductions in MAs% and iAs%. For 3 variants, associations between genotypes and iAs metabolism were significantly stronger among subjects exposed to water As >50 versus ≤50 ppb (water As X genotype interaction P < .05). In contrast, for 1 variant (rs17881215), associations were significantly stronger at exposures ≤50 ppb. Results suggest that iAs exposure may influence the extent to which several AS3MT variants affect iAs metabolism. The variants most strongly associated with iAs metabolism—and perhaps with susceptibility to iAs-associated disease—may vary in settings with exposure level. PMID:27370415

Biosorptive removal of inorganic arsenic species and fluoride from aqueous medium by the stem of Tecomella undulate.

PubMed

Brahman, Kapil Dev; Kazi, Tasneem Gul; Baig, Jameel Ahmed; Afridi, Hassan Imran; Arain, Sadaf Sadia; Saraj, Saima; Arain, Muhammad B; Arain, Salma Aslam

2016-05-01

Simultaneous removal of fluoride (F(-)), inorganic arsenic species, As(III) and As(V), from aqueous samples has been performed using an economic indigenous biosorbent (Stem of Tecomella undulata). The inorganic As species in water samples before and after biosorption were determined by cloud point and solid phase extraction methods, while F(-) was determined by ion chromatography. Batch experiments were carried out to evaluate the equilibrium adsorption isotherm studies for As(III), As(V) and F(-) in aqueous solutions. Several parameters of biosorption were optimized such as pH, biomass dosage, analytes concentration, time and temperature. The surface of biosorbent was characterized by SEM and FTIR. The FTIR study indicated the presence of carbonyl and amine functional groups which may have important role in the sorption/removal of these ions. Thermodynamic and kinetic study indicated that the biosorption of As(III), As(V) and F(-) were spontaneous, exothermic and followed by pseudo-second-order. Meanwhile, the interference study revealed that there was no significant effect of co-existing ions for the removal of inorganic As species and F(-) from aqueous samples (p > 0.05). It was observed that the indigenous biosorbent material simultaneously adsorbed As(III) (108 μg g(-1)), As(V) (159 μg g(-1)) and F(-) (6.16 mg g(-1)) from water at optimized conditions. The proposed biosorbent was effectively regenerated and efficiently used for several experiments, to remove the As(III), As(V) and F(-) from real water sample collected from endemic area of Pakistan. Copyright © 2016 Elsevier Ltd. All rights reserved.

ACCUMULATION AND METABOLISM OF ARSENIC IN MICE AFTER REPEATED ADMINISTRATION OF ARSENATE

EPA Science Inventory

Accumulation and metabolism of arsenic in mice after repeated oral administration of arsenate, Hughes, M. F., Kenyon, E. M., Edwards, B. C., Mitchell, C. T., Del Razo, L. M., and Thomas,
D. J.

The human carcinogen inorganic arsenic (iAs) is a pervasive environmental ...

Total and inorganic arsenic in foods of the first Hong Kong total diet study.

PubMed

Chung, Stephen Wai-cheung; Lam, Chi-ho; Chan, Benny Tsz-pun

2014-04-01

Arsenic (As) is a metalloid that occurs in different inorganic and organic forms, which are found in the environment from both natural occurrence and anthropogenic activity. The inorganic forms of As (iAs) are more toxic as compared with the organic As, but so far most of the occurrence data in food collected in the framework of official food control are still reported as total As without differentiating the various As species. In this paper, total As and iAs contents of 600 total diet study (TDS) samples, subdivided into 15 different food groups, were quantified by high-resolution inductively coupled plasma mass spectrometry (HR-ICP/MS) and hydride generation (HG) ICP/MS respectively. The method detection limits for both total As and iAs were 3 μg As kg(-1). As the samples were prepared for TDS, food items were purchased directly from the market or prepared as for normal consumption, i.e. table ready, in the manner most representative of and consistent with cultural habits in Hong Kong as far as practicable. The highest total As and iAs content were found in 'fish, seafood and their products' and 'vegetables and their products' respectively. Besides, this paper also presents the ratios of iAs and total As content in different ready-to-eat food items. The highest ratio of iAs to total As was found in 'vegetables and their products'. It is likely that iAs in vegetables maintained its status even after cooking.

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

Genetic, chemical, and field management strategies for reducing accumulation of arsenic in rice grains

USDA-ARS?s Scientific Manuscript database

There is public concern over amounts of arsenic contained in rice grains and foods. The World Health Organization (WHO) has set a CODEX limit of 0.2 ppm inorganic arsenic (iAs) in milled white rice, and a lower limit of 0.1 ppm for baby food products. Arsenic is of greater concern in rice than oth...

High-Purity Glasses Based on Arsenic Chalcogenides

DTIC Science & Technology

2001-06-01

Chemical interaction of chalcogenides and some impurities (CS 2, TeO2 ) with the quartz glass at high temperature leads to the thin layers formation...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO1 1523 TITLE: High-Purity Glasses Based on Arsenic Chalcogenides...Materials Vol. 3, No. 2, June 2001, p. 341 - 349 HIGH-PURITY GLASSES BASED ON ARSENIC CHALCOGENIDES M. F. Churbanov, I. V. Scripachev, G. E. Snopatin, V. S

Urinary inorganic arsenic concentrations and semen quality of male partners of subfertile couples in Tokyo.

PubMed

Oguri, Tomoko; Yoshinaga, Jun; Toshima, Hiroki; Mizumoto, Yoshifumi; Hatakeyama, Shota; Tokuoka, Susumu

2016-01-01

Inorganic arsenic (iAs) has been known as a testicular toxicant in experimental rodents. Possible association between iAs exposure and semen quality (semen volume, sperm concentration, and sperm motility) was explored in male partners of couples (n = 42) who visited a gynecology clinic in Tokyo for infertility consultation. Semen parameters were measured according to WHO guideline at the clinic, and urinary iAs and methylarsonic acid (MMA), and dimethylarsinic acid concentrations were determined by liquid chromatography-hydride generation-ICP mass spectrometry. Biological attributes, dietary habits, and exposure levels to other chemicals with known effects on semen parameters were taken into consideration as covariates. Multiple regression analyses and logistic regression analyses did not find iAs exposure as significant contributor to semen parameters. Lower exposure level of subjects (estimated to be 0.5 μg kg(-1) day(-1)) was considered a reason of the absence of adverse effects on semen parameters, which were seen in rodents dosed with 4-7.5 mg kg(-1).

Prevalence of Chronic Diseases in Adults Exposed to Arsenic-Contaminated Drinking Water

PubMed Central

Zierold, Kristina M.; Knobeloch, Lynda; Anderson, Henry

2004-01-01

Inorganic arsenic is naturally occurring in groundwaters throughout the United States. This study investigated arsenic exposure and self-report of 9 chronic diseases. We received private well-water samples and questionnaires from 1185 people who reported drinking their water for 20 or more years. Respondents with arsenic levels of 2 μg/L or greater were statistically more likely to report a history of depression, high blood pressure, circulatory problems, and bypass surgery than were respondents with arsenic concentrations less than 2 μg/L. PMID:15514231

Accumulation of arsenic in leaves and grain are affected by variety and soil arsenic

USDA-ARS?s Scientific Manuscript database

The arsenic (As) levels in rice grains and food products can reach toxic levels when produced under certain growing conditions found mostly in Asia. The World Health Organization (WHO) recently set a CODEX limit of 0.2 ppm inorganic As in milled white rice, and lower limits are expected to be set f...

75 FR 27554 - Science Advisory Board Staff Office; Request for Nominations of Experts for the SAB Arsenic...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-17

... Nominations of Experts for the SAB Arsenic Review Panel AGENCY: Environmental Protection Agency (EPA). ACTION... (IRIS) assessment for inorganic arsenic (noncancer). DATES: Nominations should be submitted by June 7...://www.epa.gov/sab . SUPPLEMENTARY INFORMATION: EPA is revising an assessment for arsenic in support of...

GENE EXPRESSION CHANGES IN MOUSE BLADDER TISSUE IN RESPONSE TO INORGANIC ARSENIC

EPA Science Inventory

Chronic human exposures to high arsenic concentrations are associated with lung, skin, and bladder cancer. Considerable controversy exists concerning arsenic mode of action and low dose extrapolation. This investigation was designed to identify dose-response changes in gene expre...

THE ROLE OF VALENCE AND METHYLATION STATE ON THE ACTIVITY OF ARSENIC DURING MITOSIS

EPA Science Inventory

Trivalent methylated arsenicals are much more potent DNA damaging agents, clastogens, and large deletion mutagens than are their inorganic and pentavalent counterparts. Previously we had noticed that many of the arsenicals induced "c-type" anaphases characteristic of spindle pois...

Total Mercury, Methylmercury, Inorganic Arsenic and Other Elements in Meat from Minke Whale (Balaenoptera acutorostrata) from the North East Atlantic Ocean.

PubMed

Maage, Amund; Nilsen, Bente M; Julshamn, Kaare; Frøyland, Livar; Valdersnes, Stig

2017-08-01

Meat samples of 84 minke whales (Balaenoptera acutorostrata) mainly from the Barents Sea, collected between 1 May and 16 August 2011, were analyzed for total mercury, methylmercury, cadmium, lead, total arsenic, inorganic arsenic and selenium. The average total mercury concentration found was 0.15 ± 0.09 mg/kg, with a range from 0.05 to 0.49 mg/kg. The molar ratio of selenium to mercury varied between 1.0 and 10.3. Cadmium content ranged from 0.002 to 0.036 mg/kg, while the content of lead in whale meat ranged from <0.01 to 0.09 mg/kg. None of the whale samples exceeded established EU maximum levels for metals in fish muscle, but 4.8% and 6.8% of the samples exceeded Japanese maximum levels for total mercury and methylmercury, respectively, in whale meat. There was only minor variations in element concentrations between whales from different geographical areas, and cadmium was the only element were the concentration increased with increasing length.

Quantification and feed to food transfer of total and inorganic arsenic from a commercial seaweed feed.

PubMed

Monagail, Michéal Mac; Cummins, Enda; Bermejo, Ricardo; Daly, Eve; Costello, Declan; Morrison, Liam

2018-06-20

Seaweed has a long-associated history of use as a supplemented livestock feed, providing nutrients and vitamins essential to maintaining animal health. Some species of seaweed, particularly the fucoids, are well-known accumulators of the metalloid arsenic (As). Arsenic toxicity to humans is well established even at low exposure levels and is considered a class 1 human carcinogen. As mankind's appetite for livestock produce continues to grow unabated, there is a concern that consumption of livestock produce reared on a diet supplemented with seaweed animal feed (SAF) may pose a threat to the human population due to potentially high levels of As present in seaweed. To address this concern and provide end users, including industry, consumers, policymakers and regulators with information on the exposure associated with As in commercial seaweed animal feed, the estimated daily intake (EDI) of As was calculated to evaluate potential human exposure levels. Using As data from a commercially available seaweed meal over a five-year period (2012-2017) a population exposure assessment was carried out. A Monte Carlo simulation model was developed to characterise the feed to food transfer of As from animal feed to animal produce such as beef, milk, chicken, and eggs. The model examined initial levels in seaweed, inclusion rate in animal feed, animal feeding rates and potential transfer to food produced from a supplemented diet of SAF. The analysis of seaweed animal feed showed that inorganic As was a small fraction of the total As found in seaweed meal (80:1). Statistical analysis found significant differences in the concentration of As in seaweed animal feed depending on the grain size (p < 0.001), with higher As concentrations in smaller sized grain fractions. Due to several detoxification steps and subsequent rapid excretion from the bodies of livestock, a very low carryover rate of As compounds from seaweed animal feed into livestock produce was observed. The EDI

Arsenic Induces p62 Expression to Form a Positive Feedback Loop with Nrf2 in Human Epidermal Keratinocytes: Implications for Preventing Arsenic-Induced Skin Cancer.

PubMed

Shah, Palak; Trinh, Elaine; Qiang, Lei; Xie, Lishi; Hu, Wen-Yang; Prins, Gail S; Pi, Jingbo; He, Yu-Ying

2017-01-24

Exposure to inorganic arsenic in contaminated drinking water poses an environmental public health threat for hundreds of millions of people in the US and around the world. Arsenic is a known carcinogen for skin cancer. However, the mechanism by which arsenic induces skin cancer remains poorly understood. Here, we have shown that arsenic induces p62 expression in an autophagy-independent manner in human HaCaT keratinocytes. In mouse skin, chronic arsenic exposure through drinking water increases p62 protein levels in the epidermis. Nrf2 is required for basal and arsenic-induced p62 up-regulation. p62 knockdown reduces arsenic-induced Nrf2 activity, and induces sustained p21 up-regulation. p62 induction is associated with increased proliferation in mouse epidermis. p62 knockdown had little effect on arsenic-induced apoptosis, while it decreased cell proliferation following arsenic treatment. Our findings indicate that arsenic induces p62 expression to regulate the Nrf2 pathway in human keratinocytes and suggest that targeting p62 may help prevent arsenic-induced skin cancer.

Development of bacteria-based bioassays for arsenic detection in natural waters.

PubMed

Diesel, Elizabeth; Schreiber, Madeline; van der Meer, Jan Roelof

2009-06-01

Arsenic contamination of natural waters is a worldwide concern, as the drinking water supplies for large populations can have high concentrations of arsenic. Traditional techniques to detect arsenic in natural water samples can be costly and time-consuming; therefore, robust and inexpensive methods to detect arsenic in water are highly desirable. Additionally, methods for detecting arsenic in the field have been greatly sought after. This article focuses on the use of bacteria-based assays as an emerging method that is both robust and inexpensive for the detection of arsenic in groundwater both in the field and in the laboratory. The arsenic detection elements in bacteria-based bioassays are biosensor-reporter strains; genetically modified strains of, e.g., Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Rhodopseudomonas palustris. In response to the presence of arsenic, such bacteria produce a reporter protein, the amount or activity of which is measured in the bioassay. Some of these bacterial biosensor-reporters have been successfully utilized for comparative in-field analyses through the use of simple solution-based assays, but future methods may concentrate on miniaturization using fiberoptics or microfluidics platforms. Additionally, there are other potential emerging bioassays for the detection of arsenic in natural waters including nematodes and clams.

High arsenic groundwater: mobilization, metabolism and mitigation--an overview in the Bengal Delta Plain.

PubMed

Bhattacharyya, Rupa; Chatterjee, Debashis; Nath, Bibhash; Jana, Joydev; Jacks, Gunnar; Vahter, Marie

2003-11-01

The widespread occurrence of high inorganic arsenic in natural waters is attributed to human carcinogen and is identified as a major global public health issue. The scale of the problem in terms of population exposure (36 million) and geographical area coverage (173 x 10(3) Km2) to high arsenic contaminated groundwater (50-3200 microgL(-1)) compared to the National drinking water standard (50 microgL(-1)) and WHO recommended provisional limit (10 microgL(-1)) is greatest in the Holocene alluvium and deltaic aquifers of the Bengal Delta Plain (Bangladesh and West Bengal, India). This large-scale 'natural' high arsenic groundwater poses a great threat to human health via drinking water. Mobilization, metabolism and mitigation issues of high arsenic groundwater are complex and need holistic approach for sustainable development of the resource. Mobilization depends on the redox geochemistry of arsenic that plays a vital role in the release and subsequent transport of arsenic in groundwater. Metabolism narrates the biological response vis-à-vis clinical manifestations of arsenic due to various chemical and biological factors. Mitigation includes alternative source for safe drinking water supply. Drinking water quality regulatory standards as well as guidelines are yet to cover risk assessments for such metal toxicity. Lowering of the ingested inorganic arsenic level and introduction of newer treatment options (implementation of laterite, the natural material) to ensure safe water supply (arsenic free and/or low arsenic within permissible limit) are the urgent need to safe guard the mass arsenic poisoning and internal arsenic related health problems.

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.

ARSENICALS IN MATERNAL AND FETAL MOUSE TISSUES AFTER GESTATIONAL EXPOSURE TO ARSENITE

EPA Science Inventory

Exposure of pregnant C3H/HeNCR mice to 42.5- or 85-ppm of arsenic as sodium arsenite in drinking water between days 8 to 18 of gestation markedly increases tumor incidence in their offspring. In the work reported here, distribution of inorganic arsenic and its metabolites, methy...

Inorganic arsenic causes fatty liver and interacts with ethanol to cause alcoholic liver disease in zebrafish.

PubMed

Bambino, Kathryn; Zhang, Chi; Austin, Christine; Amarasiriwardena, Chitra; Arora, Manish; Chu, Jaime; Sadler, Kirsten C

2018-02-26

The rapid increase in fatty liver disease (FLD) incidence is attributed largely to genetic and lifestyle factors; however, environmental toxicants are a frequently overlooked factor that can modify the effects of more common causes of FLD. Chronic exposure to inorganic arsenic (iAs) is associated with liver disease in humans and animal models, but neither the mechanism of action nor the combinatorial interaction with other disease-causing factors has been fully investigated. Here, we examined the contribution of iAs to FLD using zebrafish and tested the interaction with ethanol to cause alcoholic liver disease (ALD). We report that zebrafish exposed to iAs throughout development developed specific phenotypes beginning at 4 days post-fertilization (dpf), including the development of FLD in over 50% of larvae by 5 dpf. Comparative transcriptomic analysis of livers from larvae exposed to either iAs or ethanol revealed the oxidative stress response and the unfolded protein response (UPR) caused by endoplasmic reticulum (ER) stress as common pathways in both these models of FLD, suggesting that they target similar cellular processes. This was confirmed by our finding that arsenic is synthetically lethal with both ethanol and a well-characterized ER-stress-inducing agent (tunicamycin), suggesting that these exposures work together through UPR activation to cause iAs toxicity. Most significantly, combined exposure to sub-toxic concentrations of iAs and ethanol potentiated the expression of UPR-associated genes, cooperated to induce FLD, reduced the expression of as3mt , which encodes an arsenic-metabolizing enzyme, and significantly increased the concentration of iAs in the liver. This demonstrates that iAs exposure is sufficient to cause FLD and that low doses of iAs can potentiate the effects of ethanol to cause liver disease.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

HEALTH EFFECTS FROM CHRONIC EXPOSURE TO ARSENIC VIA DRINKING WATER IN INNER MONGOLIA

EPA Science Inventory

Arsenite and arsenate are widely present in natural waters. The inorganic forms , especially arsenite, are believed to be the most toxic species. Methylation is often considered to be the primary detoxification pathway for the metaboliism of inorganic arsenic. Recently studi...

Hijacking membrane transporters for arsenic phytoextraction

PubMed Central

LeBlanc, Melissa S.; McKinney, Elizabeth C.; Meagher, Richard B.; Smith, Aaron P.

2012-01-01

Arsenic is a toxic metalloid and recognized carcinogen. Arsenate and arsenite are the most common arsenic species available for uptake by plants. As an inorganic phosphate (Pi) analog, arsenate is acquired by plant roots through endogenous Pi transport systems. Inside the cell, arsenate is reduced to the thiol-reactive form arsenite. Glutathione (GSH)-conjugates of arsenite may be extruded from the cell or sequestered in vacuoles by members of the ATP-binding cassette (ABC) family of transporters. In the present study we sought to enhance both plant arsenic uptake through Pi transporter overexpression, and plant arsenic tolerance through ABC transporter overexpression. We demonstrate that Arabidopsis thaliana plants overexpressing the high-affinity Pi transporter family members, AtPht1;1 or AtPht1;7, are hypersensitive to arsenate due to increased arsenate uptake. These plants do not exhibit increased sensitivity to arsenite. Co-overexpression of the yeast ABC transporter YCF1 in combination with AtPht1;1 or AtPht1;7 suppresses the arsenate-sensitive phenotype while further enhancing arsenic uptake. Taken together, our results support an arsenic transport mechanism in which arsenate uptake is increased through Pi transporter overexpression, and arsenic tolerance is enhanced through YCF1-mediated vacuolar sequestration. This work substantiates the viability of coupling enhanced uptake and vacuolar sequestration as a means for developing a prototypical engineered arsenic hyperaccumulator. PMID:23108027

Microbial arsenic metabolism: New twists on an old poison

USGS Publications Warehouse

Stolz, J.F.; Basu, P.; Oremland, R.S.

2010-01-01

Phylogenetically diverse microorganisms metabolize arsenic despite its toxicity and are part of its robust iogeochemical cycle. Respiratory arsenate reductase is a reversible enzyme, functioning in some microbes as an arsenate reductase but in others as an arsenite oxidase. As(III) can serve as an electron donor for anoxygenic photolithoautotrophy and chemolithoautotrophy. Organoarsenicals, such as the feed additive roxarsone, can be used as a source of energy, releasing inorganic arsenic.

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.

Bacterial metabolism of environmental arsenic--mechanisms and biotechnological applications.

PubMed

Kruger, Martin C; Bertin, Philippe N; Heipieper, Hermann J; Arsène-Ploetze, Florence

2013-05-01

Arsenic causes threats for environmental and human health in numerous places around the world mainly due to its carcinogenic potential at low doses. Removing arsenic from contaminated sites is hampered by the occurrence of several oxidation states with different physicochemical properties. The actual state of arsenic strongly depends on its environment whereby microorganisms play important roles in its geochemical cycle. Due to its toxicity, nearly all organisms possess metabolic mechanisms to resist its hazardous effects, mainly by active extrusion, but also by extracellular precipitation, chelation, and intracellular sequestration. Some microbes are even able to actively use various arsenic compounds in their metabolism, either as an electron donor or as a terminal electron acceptor for anaerobic respiration. Some microorganisms can also methylate inorganic arsenic, probably as a resistance mechanism, or demethylate organic arsenicals. Bioavailability of arsenic in water and sediments is strongly influenced by such microbial activities. Therefore, understanding microbial reactions to arsenic is of importance for the development of technologies for improved bioremediation of arsenic-contaminated waters and environments. This review gives an overview of the current knowledge on bacterial interactions with arsenic and on biotechnologies for its detoxification and removal.

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.

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

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 Exposure, Arsenic Metabolism, and Incident Diabetes in the Strong Heart Study

PubMed Central

Howard, Barbara V.; Umans, Jason G.; Gribble, Matthew O.; Best, Lyle G.; Francesconi, Kevin A.; Goessler, Walter; Lee, Elisa; Guallar, Eliseo; Navas-Acien, Ana

2015-01-01

OBJECTIVE Little is known about arsenic metabolism in diabetes development. We investigated the prospective associations of low-moderate arsenic exposure and arsenic metabolism with diabetes incidence in the Strong Heart Study. RESEARCH DESIGN AND METHODS A total of 1,694 diabetes-free participants aged 45–75 years were recruited in 1989–1991 and followed through 1998–1999. We used the proportions of urine inorganic arsenic (iAs), monomethylarsonate (MMA), and dimethylarsinate (DMA) over their sum (expressed as iAs%, MMA%, and DMA%) as the biomarkers of arsenic metabolism. Diabetes was defined as fasting glucose ≥126 mg/dL, 2-h glucose ≥200 mg/dL, self-reported diabetes history, or self-reported use of antidiabetic medications. RESULTS Over 11,263.2 person-years of follow-up, 396 participants developed diabetes. Using the leave-one-out approach to model the dynamics of arsenic metabolism, we found that lower MMA% was associated with higher diabetes incidence. The hazard ratios (95% CI) of diabetes incidence for a 5% increase in MMA% were 0.77 (0.63–0.93) and 0.82 (0.73–0.92) when iAs% and DMA%, respectively, were left out of the model. DMA% was associated with higher diabetes incidence only when MMA% decreased (left out of the model) but not when iAs% decreased. iAs% was also associated with higher diabetes incidence when MMA% decreased. The association between MMA% and diabetes incidence was similar by age, sex, study site, obesity, and urine iAs concentrations. CONCLUSIONS Arsenic metabolism, particularly lower MMA%, was prospectively associated with increased incidence of diabetes. Research is needed to evaluate whether arsenic metabolism is related to diabetes incidence per se or through its close connections with one-carbon metabolism. PMID:25583752

Biological and behavioral modifiers of urinary arsenic metabolic profiles in a U.S. population

EPA Science Inventory

Biological and behavioral modifiers of urinary arsenic metabolic profiles in a U.S. population David J. Thomas – ISTD, NHEERL Edward F. Hudgens – EHPD, NHEERL John Rogers - Westat Relations between intensity of arsenic exposure from home tap water and levels of inorganic As ...

SEPARATION OF TOXICOLOGICALLY RELEVANT ARSENICALS IN URINE USING A NEW SOLID PHASE EXTRACTION TECHNIQUE

EPA Science Inventory

Abstract - Metabolism and toxicity of arsenicals are critically influenced by the oxidation state of As. In human urine, inorganic and methylated arsenicals contain both As(III) and As(V). Because As(III) is easily oxidized, a method is needed to preserve the native oxidation sta...

Modeling the probability of arsenic in groundwater in New England as a tool for exposure assessment.

PubMed

Ayotte, Joseph D; Nolan, Bernard T; Nuckols, John R; Cantor, Kenneth P; Robinson, Gilpin R; Baris, Dalsu; Hayes, Laura; Karagas, Margaret; Bress, William; Silverman, Debra T; Lubin, Jay H

2006-06-01

We developed a process-based model to predict the probability of arsenic exceeding 5 microg/L in drinking water wells in New England bedrock aquifers. The model is being used for exposure assessment in an epidemiologic study of bladder cancer. One important study hypothesis that may explain increased bladder cancer risk is elevated concentrations of inorganic arsenic in drinking water. In eastern New England, 20-30% of private wells exceed the arsenic drinking water standard of 10 micrograms per liter. Our predictive model significantly improves the understanding of factors associated with arsenic contamination in New England. Specific rock types, high arsenic concentrations in stream sediments, geochemical factors related to areas of Pleistocene marine inundation and proximity to intrusive granitic plutons, and hydrologic and landscape variables relating to groundwater residence time increase the probability of arsenic occurrence in groundwater. Previous studies suggest that arsenic in bedrock groundwater may be partly from past arsenical pesticide use. Variables representing historic agricultural inputs do not improve the model, indicating that this source does not significantly contribute to current arsenic concentrations. Due to the complexity of the fractured bedrock aquifers in the region, well depth and related variables also are not significant predictors.

Peripheral Arterial Disease and Its Association With Arsenic Exposure and Metabolism in the Strong Heart Study

PubMed Central

Newman, Jonathan D.; Navas-Acien, Ana; Kuo, Chin-Chi; Guallar, Eliseo; Howard, Barbara V.; Fabsitz, Richard R.; Devereux, Richard B.; Umans, Jason G.; Francesconi, Kevin A.; Goessler, Walter; Best, Lyle T.; Tellez-Plaza, Maria

2016-01-01

At high levels, inorganic arsenic exposure is linked to peripheral arterial disease (PAD) and cardiovascular disease. To our knowledge, no prior study has evaluated the association between low-to-moderate arsenic exposure and incident PAD by ankle brachial index (ABI). We evaluated this relationship in the Strong Heart Study, a large population-based cohort study of American Indian communities. A total of 2,977 and 2,966 PAD-free participants who were aged 45–74 years in 1989–1991 were reexamined in 1993–1995 and 1997–1999, respectively, for incident PAD defined as either ABI <0.9 or ABI >1.4. A total of 286 and 206 incident PAD cases were identified for ABI <0.9 and ABI >1.4, respectively. The sum of inorganic and methylated urinary arsenic species (∑As) at baseline was used as a biomarker of long-term exposure. Comparing the highest tertile of ∑As with the lowest, the adjusted hazard ratios were 0.57 (95% confidence interval (CI): 0.32, 1.01) for ABI <0.9 and 2.24 (95% CI: 1.01, 4.32) for ABI >1.4. Increased arsenic methylation (as percent dimethylarsinate) was associated with a 2-fold increased risk of ABI >1.4 (hazard ratio = 2.04, 95% CI: 1.02, 3.41). Long-term low-to-moderate ∑As and increased arsenic methylation were associated with ABI >1.4 but not with ABI <0.9. Further studies are needed to clarify whether diabetes and enhanced arsenic metabolism increase susceptibility to the vasculotoxic effects of arsenic exposure. PMID:27810857

[Studies on markers of exposure and early effect in areas with arsenic pollution: methods and results of the project SEpiAs. Epidemiological studies on population exposed to low-to-moderate arsenic concentration in drinking water].

PubMed

Bustaffa, Elisa; Bianchi, Fabrizio

2014-01-01

Arsenic and its inorganic compounds are classified as human carcinogens. Several epidemiological studies conducted in areas of the world characterized by high arsenic concentration in drinking water, even up to 3,000 μg/l, report associations between arsenic exposure and skin, bladder, lung, liver and kidney cancer as well as cardiovascular diseases, diabetes and reproductive and developmental effects. Since general population is not exposed to these high arsenic concentrations in the last years attention focused on adverse health effects that low-to-moderate arsenic concentrations (0-150 μg/l) in drinking water could induce. The World Health Organization recommends a maximum limit of 10 μg/l for arsenic in drinking water. Almost all epidemiological studies conducted on populations exposed to low-to-moderate arsenic concentrations in drinking water are limited due to problems arising from both individual exposure assessment and low subjects number. The aim of the present review is to collect literature-based evidences regarding adverse health effects associated with exposure to low-to-moderate arsenic concentrations in drinking water (10-150 μg/l) in order to obtain a comprehensive picture of the health outcomes that such exposure can have on general population.

Efficacy of indigenous soil microbes in arsenic mitigation from contaminated alluvial soil of India.

PubMed

Majumder, Aparajita; Bhattacharyya, Kallol; Kole, S C; Ghosh, Sagarmoy

2013-08-01

Selected arsenic-volatilizing indigenous soil bacteria were isolated and their ability to form volatile arsenicals from toxic inorganic arsenic was assessed. Approximately 37 % of AsIII (under aerobic conditions) and 30 % AsV (under anaerobic conditions) were volatilized by new bacterial isolates in 3 days. In contrast to genetically modified organism, indigenous soil bacteria was capable of removing 16 % of arsenic from contaminated soil during 60 days incubation period while applied with a low-cost organic nutrient supplement (farm yard manure).

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...

Glutathione-S-transferase-omega [MMA(V) reductase] knockout mice: Enzyme and arsenic species concentrations in tissues after arsenate administration

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

Chowdhury, Uttam K.; Zakharyan, Robert A.; Hernandez, Alba

Inorganic arsenic is a human carcinogen to which millions of people are exposed via their naturally contaminated drinking water. Its molecular mechanisms of carcinogenicity have remained an enigma, perhaps because arsenate is biochemically transformed to at least five other arsenic-containing metabolites. In the biotransformation of inorganic arsenic, GSTO1 catalyzes the reduction of arsenate, MMA(V), and DMA(V) to the more toxic + 3 arsenic species. MMA(V) reductase and human (hGSTO1-1) are identical proteins. The hypothesis that GST-Omega knockout mice biotransformed inorganic arsenic differently than wild-type mice has been tested. The livers of male knockout (KO) mice, in which 222 bp ofmore » Exon 3 of the GSTO1 gene were eliminated, were analyzed by PCR for mRNA. The level of transcripts of the GSTO1 gene in KO mice was 3.3-fold less than in DBA/1lacJ wild-type (WT) mice. The GSTO2 transcripts were about two-fold less in the KO mouse. When KO and WT mice were injected intramuscularly with Na arsenate (4.16 mg As/kg body weight); tissues removed at 0.5, 1, 2, 4, 8, and 12 h after arsenate injection; and the arsenic species measured by HPLC-ICP-MS, the results indicated that the highest concentration of the recently discovered and very toxic MMA(III), a key biotransformant, was in the kidneys of both KO and WT mice. The highest concentration of DMA(III) was in the urinary bladder tissue for both the KO and WT mice. The MMA(V) reducing activity of the liver cytosol of KO mice was only 20% of that found in wild-type mice. There appears to be another enzyme(s) other than GST-O able to reduce arsenic(V) species but to a lesser extent. This and other studies suggest that each step of the biotransformation of inorganic arsenic has an alternative enzyme to biotransform the arsenic substrate.« less

THE VALENCE AND METHYLATION STATE OF ARSENIC DETERMINES ITS POTENCY IN INTERACTION WITH THE MITOTIC APPARATUS

EPA Science Inventory

We have previously shown that the cytotoxic and genotoxic potency of arsenicals is dependent upon their valence and methylation state. Trivalent methylated arsenicals are much more potent DNA damaging agents than are their inorganic and pentavalent counterparts. Furthermore, thei...

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...

Chronic early childhood exposure to arsenic is associated with a TNF-mediated proteomic signaling response.

PubMed

Smeester, Lisa; Bommarito, Paige A; Martin, Elizabeth M; Recio-Vega, Rogelio; Gonzalez-Cortes, Tania; Olivas-Calderon, Edgar; Lantz, R Clark; Fry, Rebecca C

2017-06-01

Exposure to inorganic arsenic (iAs) in drinking water is a global public health concern and is associated with a range of health outcomes, including immune dysfunction. Children are a particularly sensitive population to the effects of inorganic arsenic, yet the biological mechanisms underlying adverse health outcomes are understudied. Here we used a proteomic approach to examine the effects of iAs exposure on circulating serum protein levels in a cross-sectional children's cohort in Mexico. To identify iAs-associated proteins, levels of total urinary arsenic (U-tAs) and its metabolites were determined and serum proteins assessed for differences in expression. The results indicate an enrichment of Tumor Necrosis Factor-(TNF)-regulated immune and inflammatory response proteins that displayed decreased expression levels in relation to increasing U-tAs. Notably, when analyzed in the context of the proportions of urinary arsenic metabolites in children, the most robust response was observed in relation to the monomethylated arsenicals. This study is among the first serum proteomics assessment in children exposed to iAs. Copyright © 2017 Elsevier B.V. All rights reserved.

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...

Magentite nanoparticle for arsenic remotion.

NASA Astrophysics Data System (ADS)

Viltres, H.; Odio, O. F.; Borja, R.; Aguilera, Y.; Reguera, E.

2017-01-01

Inorganic As (V) and As (III) species are commonly found in groundwater in many countries around the world. It is known that arsenic is highly toxic and carcinogenic, at present exist reports of diverse countries with arsenic concentrations in drinking water higher than those proposed by the World Health Organization (10 μg/L). It has been reported that adsorption strategies using magnetic nanoparticles as magnetite (<20 nm) proved to be very efficient for the removal of arsenic in drinking water. Magnetic nanoparticles (magnetite) were prepared using a co-precipitation method with FeCl3 and FeCl2 as metal source and NaOH aqueous solution as precipitating agent. Magnetite nanoparticles synthesized were put in contact with As2O3 and As2O5 solutions at room temperature to pH 4 and 7. The nanoparticles were characterized by FT-IR, DRX, UV-vis, and XRF. The results showed that synthesized magnetite had an average diameter of 11 nm and a narrow size distribution. The presence of arsenic on magnetite nanoparticles surface was confirmed, which is more remarkable when As (V) is employed. Besides, it is possible to observe that no significant changes in the band gap values after adsorption of arsenic in the nanoparticles.

HEALTH EFFECTS AND RISK ASSESSMENT OF ARSENIC

EPA Science Inventory

Abstract - In this review, we will focus on the effects of arsenic (As) exposure from drinking water sources. The primary inorganic As species in water are arsenate (V) and/or arsenite (III); their proportions depend on the water's redox potential and pH. Many As contamination...

The relation between rice consumption, arsenic contamination, and prevalence of diabetes in South Asia

PubMed Central

Hassan, Fatima Ismail; Niaz, Kamal; Khan, Fazlullah; Maqbool, Faheem; Abdollahi, Mohammad

2017-01-01

Rice is the major staple food for about two billion people living in Asia. It has been reported to contain considerable amount of inorganic arsenic which is toxic to pancreatic beta cells and disrupt glucose homeostasis. Articles and conference papers published between 1992 and 2017, indexed in Scopus, PubMed, EMBASE, Google, and Google scholar were used. Arsenic exposure has been associated with increased blood glucose and insulin levels, or decreased sensitization of insulin cells to glucose uptake. Several studies have shown the association between inorganic arsenic exposure and incidence of diabetes mellitus. Considerable amounts of arsenic have been reported in different types of rice which may be affected by cultivation methods, processing, and country of production. Use of certain microbes, fertilizers, and enzymes may reduce arsenic uptake or accumulation in rice, which may reduce its risk of toxicity. Combined exposure to contaminated rice, other foods and drinking water may increase the risk of diabetes in these countries. Maximum tolerated daily intake of arsenic contaminated rice (2.1 µg/day kg body weight) has been set by WHO, which may be exceeded depending on its content in rice and amount consumed. Hence, increased prevalence of diabetes in South Asia may be related to the consumption of arsenic contaminated rice depending on its content in the rice and daily amount consumed. In this review, we have focused on the possible relation between rice consumption, arsenic contamination, and prevalence of diabetes in South Asia. PMID:29285009

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.

Rapid oxidation of geothermal arsenic(III) in streamwaters of the eastern Sierra Nevada

USGS Publications Warehouse

Wilkie, J.A.; Hering, J.G.

1998-01-01

Arsenic redox cycling was examined in source waters of the Los Angeles Aqueduct, specifically at Hot Creek, a tributary of the Owens River. Elevated arsenic concentrations in Hot Creek result from geothermal inputs. Total arsenic and As(III) concentrations were determined in the creek and in hot spring pools along its banks. Samples were processed in the field using anion-exchange columns to separate inorganic As(III) and As(V) species. Downstream of the geothermal inputs, decreasing contributions of As(III) to total arsenic concentrations indicated rapid in-stream oxidation of As(III) to As(V) with almost complete oxidation occurring within 1200 m. Based on assumed plug flow transport and a flow velocity of about 0.4 m/s, the pseudo- first-order half-life calculated for this reaction was approximately 0.3 h. Conservative transport of total dissolved arsenic was observed over the reach. Pseudo-first-order reaction rates determined for As(III) oxidation in batch studies conducted in the field with aquatic macrophytes and/or macrophyte surface matter were comparable to the in-stream oxidation rate observed along Hot Creek. In batch kinetic studies, oxidation was not observed after sterile filtration or after the addition of antibiotics, which indicates that bacteria attached to submerged macrophytes are mediating the rapid As(III) oxidation reaction.Arsenic redox cycling was examined in source waters of the Los Angeles Aqueduct, specifically at Hot Creek, a tributary of the Owens River. Elevated arsenic concentrations in Hot Creek result from geothermal inputs. Total arsenic and As(III) concentrations were determined in the creek and in hot spring pools along its banks. Samples were processed in the field using anion-exchange columns to separate inorganic As(III) and As(V) species. Downstream of the geothermal inputs, decreasing contributions of As(III) to total arsenic concentrations indicated rapid in-stream oxidation of As(III) to As(V) with almost complete

The microbial arsenic cycle in Mono Lake, California

USGS Publications Warehouse

Oremland, Ronald S.; Stolz, John F.; Hollibaugh, James T.

2004-01-01

Significant concentrations of dissolved inorganic arsenic can be found in the waters of a number of lakes located in the western USA and in other water bodies around the world. These lakes are often situated in arid, volcanic terrain. The highest concentrations of arsenic occur in hypersaline, closed basin soda lakes and their remnant brines. Although arsenic is a well-known toxicant to eukaryotes and prokaryotes alike, some prokaryotes have evolved biochemical mechanisms to exploit arsenic oxyanions (i.e., arsenate and arsenite); they can use them either as an electron acceptor for anaerobic respiration (arsenate), or as an electron donor (arsenite) to support chemoautotrophic fixation of CO2 into cell carbon. Unlike in freshwater or marine ecosystems, these processes may assume quantitative significance with respect to the carbon cycle in arsenic-rich soda lakes. For the past several years our research has focused on the occurrence and biogeochemical manifestations of these processes in Mono Lake, a particularly arsenic-rich environment. Herein we review some of our findings concerning the biogeochemical arsenic cycle in this lake, with the hope that it may broaden the understanding of the influence of microorganisms upon the speciation of arsenic in more common, less “extreme” environments, such as drinking water aquifers.

Characterization of arsenic resistant bacteria from arsenic rich groundwater of West Bengal, India.

PubMed

Sarkar, Angana; Kazy, Sufia K; Sar, Pinaki

2013-03-01

Sixty-four arsenic (As) resistant bacteria isolated from an arsenic rich groundwater sample of West Bengal were characterized to investigate their potential role in subsurface arsenic mobilization. Among the isolated strains predominance of genera Agrobacterium/Rhizobium, Ochrobactrum and Achromobacter which could grow chemolitrophically and utilize arsenic as electron donor were detected. Higher tolerance to As(3+) [maximum tolerable concentration (MTC): ≥10 mM], As(5+) (MTC: ≥100 mM) and other heavy metals like Cu(2+), Cr(2+), Ni(2+) etc. (MTC: ≥10 mM), presence of arsenate reductase and siderophore was frequently observed among the isolates. Ability to produce arsenite oxidase and phosphatase enzyme was detected in 50 and 34 % of the isolates, respectively. Although no direct correlation among taxonomic identity of bacterial strains and their metabolic abilities as mentioned above was apparent, several isolates affiliated to genera Ochrobactrum, Achromobacter and unclassified Rhizobiaceae members were found to be highly resistant to As(3+) and As(5+) and positive for all the test properties. Arsenate reductase activity was found to be conferred by arsC gene, which in many strains was coupled with arsenite efflux gene arsB as well. Phylogenetic incongruence between the 16S rRNA and ars genes lineages indicated possible incidence of horizontal gene transfer for ars genes. Based on the results we propose that under the prevailing low nutrient condition inhabitant bacteria capable of using inorganic electron donors play a synergistic role wherein siderophores and phosphatase activities facilitate the release of sediment bound As(5+), which is subsequently reduced by arsenate reductase resulting into the mobilization of As(3+) in groundwater.

Microbial-driven arsenic cycling in rice paddies amended with monosodium methanearsonate

NASA Astrophysics Data System (ADS)

Maguffin, S. C.; McClung, A.; Rohila, J. S.; Derry, L. A.; Huang, R.; Reid, M. C.

2017-12-01

Rice consumption is the second largest contributor to human arsenic exposure worldwide and is linked to many serious diseases. Because rice is uniquely adapted for agricultural production under flooded soils, arsenic species solubilized in such environments can be effectively transported into plant tissue via root transporters. Through this process, both inorganic and organic (methylated) arsenic species can accumulate to problematic concentrations and may affect grain yield as well as crop value. The distribution of these species in plant tissue is determined by arsenic sources, as well as enzymatic redox and methylation-demethylation reactions in soils and pore water. Historic use of organoarsenic-based pesticides in US agriculture may provide an enduring source of arsenic in rice paddies. However, it is unclear how persistent these organic species are in the adsorbed phase or how available they remain to rice cultivars throughout the growing season. We conducted a field experiment in a 2x2 factorial design examining the effects of irrigation methods (continuous flooding and alternate wetting and drying) and monosodium methanearsonate (MSMA) application on the abundance and speciation of arsenic in pore water, soil, and rice plant tissues. We monitored arsenic speciation and partitioning between these reservoirs at semi-weekly to semi-monthly frequencies. Pore water arsenic speciation was determined using LC-ICP-MS, and X-ray absorption near-edge structure (XANES) analysis was employed to speciate the arsenic within solid-phase soil and plant tissue throughout the growing season. These data help clarify the role of two irrigation methods and MSMA amendments for arsenic bioavailability and speciation in rice. Furthermore, the study illuminates the significance of microbial metabolism in the reapportionment of arsenic within the soil-plant-water system and its impact on arsenic levels in rice grains.

Arsenic geochemistry of groundwater in Southeast Asia.

PubMed

Kim, Kyoung-Woong; Chanpiwat, Penradee; Hanh, Hoang Thi; Phan, Kongkea; Sthiannopkao, Suthipong

2011-12-01

The occurrence of high concentrations of arsenic in the groundwater of the Southeast Asia region has received much attention in the past decade. This study presents an overview of the arsenic contamination problems in Vietnam, Cambodia, Lao People's Democratic Republic and Thailand. Most groundwater used as a source of drinking water in rural areas has been found to be contaminated with arsenic exceeding the WHO drinking water guideline of 10 μg·L(-1). With the exception of Thailand, groundwater was found to be contaminated with naturally occurring arsenic in the region. Interestingly, high arsenic concentrations (> 10 μg·L(-1)) were generally found in the floodplain areas located along the Mekong River. The source of elevated arsenic concentrations in groundwater is thought to be the release of arsenic from river sediments under highly reducing conditions. In Thailand, arsenic has never been found naturally in groundwater, but originates from tin mining activities. More than 10 million residents in Southeast Asia are estimated to be at risk from consuming arsenic-contaminated groundwater. In Southeast Asia, groundwater has been found to be a significant source of daily inorganic arsenic intake in humans. A positive correlation between groundwater arsenic concentration and arsenic concentration in human hair has been observed in Cambodia and Vietnam. A substantial knowledge gap exists between the epidemiology of arsenicosis and its impact on human health. More collaborative studies particularly on the scope of public health and its epidemiology are needed to conduct to fulfill the knowledge gaps of As as well as to enhance the operational responses to As issue in Southeast Asian countries.

Tissue-specific distributions of inorganic arsenic and its methylated metabolites, especially in cerebral cortex, cerebellum and hippocampus of mice after a single oral administration of arsenite.

PubMed

Li, Jinlong; Duan, Xiaoxu; Dong, Dandan; Zhang, Yang; Zhao, Lu; Li, Wei; Chen, Jinli; Sun, Guifan; Li, Bing

2017-09-01

Groundwater contaminated with inorganic arsenic (iAs) is the main source of human exposure to arsenic and generates a global health issue. In this study, the urinary excretion, as well as the time-course distributions of various arsenic species in murine tissues, especially in different brain regions were determined after a single oral administration of 2.5, 5, 10 and 20mg/kg sodium arsenite (NaAsO 2 ). Our data showed that the peak times of urinary, hepatic and nephritic total arsenic (TAs) were happened at about 1h, then TAs levels decreased gradually and almost could not be observed after 72h. On contrast, the time course of TAs in lung, urinary bladder and different brain regions exhibited an obvious process of accumulation and elimination,and the peak times were nearly at 6h to 9h. TAs levels of 10 and 20mg/kg NaAsO 2 groups were significantly higher than 2.5 and 5mg/kg groups, and the amounts of TAs in 5mg/kg groups were in the order of liver>lung>kidney>urinary bladder>hippocampus>cerebral cortex>cerebellum. In addition, iAs was the most abundant species in liver and kidney, while lung and urinary bladder accumulated the highest concentrations of dimethylated arsenicals (DMA). What's more, the distributions of arsenic species were not homogeneous among different brain regions, as DMA was the sole species in cerebral cortex and cerebellum, while extremely high concentrations and percentages of monomethylated arsenicals (MMA) were found in hippocampus. These results demonstrated that distributions of iAs and its methylated metabolites were tissue-specific and even not homogeneous among different brain regions, which must be considered as to the tissue- and region-specific toxicity of iAs exposure. Our results thus provide useful information for clarifying and reducing the uncertainty in the risk assessment for this metalloid. Copyright © 2016 Elsevier GmbH. All rights reserved.

Capillary electrophoresis of inorganic anions.

PubMed

Kaniansky, D; Masár, M; Marák, J; Bodor, R

1999-02-26

This review deals with the separation mechanisms applied to the separation of inorganic anions by capillary electrophoresis (CE) techniques. It covers various CE techniques that are suitable for the separation and/or determination of inorganic anions in various matrices, including capillary zone electrophoresis, micellar electrokinetic chromatography, electrochromatography and capillary isotachophoresis. Detection and sample preparation techniques used in CE separations are also reviewed. An extensive part of this review deals with applications of CE techniques in various fields (environmental, food and plant materials, biological and biomedical, technical materials and industrial processes). Attention is paid to speciations of anions of arsenic, selenium, chromium, phosphorus, sulfur and halogen elements by CE.

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.

Modelling the arsenic (V) and (III) adsorption

NASA Astrophysics Data System (ADS)

Rau, I.; Meghea, A.; Peleanu, I.; Gonzalo, A.; Valiente, M.; Zaharescu, M.

2003-01-01

Arsenic has gained great notoriety historically for its toxic properties. In aquatic environment, arsenic can exist in several oxidation states, as both inorganic and organometallic species. As (V) is less toxic than As (III). Most research has been directed to the control of arsenic pollution of potable water. Various techniques such as precipitation with iron and aluminium hydroxides, ion exchange, reverse osmosis, and adsorption are used for As (V) removal from surface and waste waters. Because of the easy handling of sludge, its free operation and regeneration capability, the adsorption technique has secured a place as one of the advanced methods of arsenic removal. A study of As (III) and As (V) sorption onto some different adsorbents (Fe (III) — iminodiacetate resin, nanocomposite materials, Fe(III) — forager sponge) referring to kinetic considerations and modelling of the process will be presented. All the systems studied are better described by Freundlich-Langmuir isotherm and the rate constant evaluation shows a sub-unitary order for the adsorption process.

A comparison of the determination and speciation of inorganic arsenic using general HPLC methodology with UV, MS and MS/MS detection.

PubMed

Gilmartin, Gregory; Gingrich, Diane

2018-04-15

The determination and speciation of arsenic in natural resources such as drinking water and agricultural soils has been a growing concern in recent years due to its many toxicological effects [1-3]. To speciate and quantitate concentrations of <1 ppm of arsenic, typically an ion chromatograph (IC) interfaced to an inductively coupled plasma mass spectrometer (ICP-MS) is employed [4-9]. This methodology may be very robust and sensitive, but it is expensive and not as ubiquitous as high performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance detection or electrospray ionization mass spectrometry (ESI-MS). Anion exchange chromatography is a well-documented means of speciating arsenite (As(III), As 2 O 3 ) and arsenate (As(V), AsO 4 ) using UV [10], conductivity [11], or ESI-MS detection [12,13]. This paper demonstrates the utilization of common liquid chromatographic instrumentation to speciate and determines inorganic Arsenic compounds using UV or MS via selected ion recording (SIR) or multiple reaction monitoring (MRM) detection. This paper describes the analysis of arsenite and arsenate samples prepared using both deionized and ground water. The limit of quantitation for the techniques described in this paper for samples spiked in ground water were 454 ppb (As(III)) and 562 ppb (As(V)) for UV detection, 45.4 ppb (As(III)) and 56.2 ppb (As(V)) for SIR detection, and 4.54 ppb (As(III)) and 5.62 ppb (As(V)) for MRM detection. Copyright © 2018 Elsevier B.V. All rights reserved.

Modeling the probability of arsenic in groundwater in New England as a tool for exposure assessment

USGS Publications Warehouse

Ayotte, J.D.; Nolan, B.T.; Nuckols, J.R.; Cantor, K.P.; Robinson, G.R.; Baris, D.; Hayes, L.; Karagas, M.; Bress, W.; Silverman, D.T.; Lubin, J.H.

2006-01-01

We developed a process-based model to predict the probability of arsenic exceeding 5 ??g/L in drinking water wells in New England bedrock aquifers. The model is being used for exposure assessment in an epidemiologic study of bladder cancer. One important study hypothesis that may explain increased bladder cancer risk is elevated concentrations of inorganic arsenic in drinking water. In eastern New England, 20-30% of private wells exceed the arsenic drinking water standard of 10 micrograms per liter. Our predictive model significantly improves the understanding of factors associated with arsenic contamination in New England. Specific rock types, high arsenic concentrations in stream sediments, geochemical factors related to areas of Pleistocene marine inundation and proximity to intrusive granitic plutons, and hydrologic and landscape variables relating to groundwater residence time increase the probability of arsenic occurrence in groundwater. Previous studies suggest that arsenic in bedrock groundwater may be partly from past arsenical pesticide use. Variables representing historic agricultural inputs do not improve the model, indicating that this source does not significantly contribute to current arsenic concentrations. Due to the complexity of the fractured bedrock aquifers in the region, well depth and related variables also are not significant predictors. ?? 2006 American Chemical Society.

T05 DETERMINATION OF REDUCED ARSENIC-THIO SPECIES IN WATERS BY ION CHROMATOGRAPHY-INDUCTIVELY-COUPLED PLASMA-MASS SSPECTROMETRY (IC-ICP-MS).

EPA Science Inventory

Elevated arsenic concentrations in ground water are a significant concern for human health, because they may lead to increased arsenic exposure via drinking water. As the inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) are known carcinogens, it is desirable to r...

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

SPECIATION OF ARSENIC IN BIOLOGICAL MATRICES BY AUTOMATED HG-AAS WITH MULTIPLE MICROFLAME QUARTZ TUBE ATOMIZER (MULTIATOMIZER)

EPA Science Inventory

Analyses of arsenic (As) species in body fluids and tissues of individuals chronically exposed to inorganic arsenic (iAs) provide essential information about the exposure level and pattern of iAs metabolism. This information facilitates the risk assessment of disorders associated...