Página 1 dos resultados de 3946 itens digitais encontrados em 0.010 segundos

Desenvolvimento de métodos rápidos de preparo de amostras para especiação química de arsênio em alimentos por LC-ICP-MS e avaliação das concentrações e do metabolismo em arroz; Development of rapid methods for sample preparation and chemical speciation of arsenic in foods by LC-ICP-MS and evaluation of metabolism and concentration in rice

Batista, Bruno Lemos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/06/2012 PT
Relevância na Pesquisa
37.24%
O arsênio é um dos mais tóxicos elementos químicos e reconhecidamente carcinogênico. Ele pode ser encontrado em alimentos basicamente em 5 formas: arsenobetaína (AsB), dimetil-arsênio (DMA), monometil-arsênio (MMA), arsenato (As5+) e arsenito (As3+), sendo estas duas últimas (As-i) as mais tóxicas. Assim, é de suma importância a utilização da especiação química de As para avaliação dos reais riscos associados à ingestão de alimentos contaminados. Neste sentido, o presente trabalho teve como objetivos o desenvolvimento de um método para separação das espécies de As por LC e detecção por ICP-MS; extrações quantitativas das espécies de As de tecidos animais e em grãos de arroz; aplicação dos métodos em amostras de alimentos consumidos no Brasil; e estudo do metabolismo do As em diferentes cultivares de arroz. O método desenvolvido para a extração das espécies de As em tecidos animais (ovo, músculos de ave, peixe e boi, etc.) utilizou apenas metanol (10%v/v) e ácido nítrico (2%v/v) como extratores e 2 minutos de sonicação, mostrando recuperação quantitativa do analito (>88%, n=3) pela análise dos materiais de referência (CE278, DOLT-3, DORM-3 e SRM NIST 1577). No entanto, para a análise de arroz...

Nutlin-3 overcomes arsenic trioxide resistance and tumor metastasis mediated by mutant p53 in Hepatocellular Carcinoma

Zheng, Tongsen; Yin, Dalong; Lu, Zhaoyang; Wang, Jiabei; Li, Yuejin; Chen, Xi; Liang, Yingjian; Song, Xuan; Qi, Shuyi; Sun, Boshi; Xie, Changming; Meng, Xianzhi; Pan, Shangha; Liu, Jiaren; Jiang, Hongchi; Liu, Lianxin
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
37.22%
Background: Arsenic trioxide has been demonstrated as an effective anti-cancer drug against leukemia and solid tumors both in vitro and in vivo. However, recent phase II trials demonstrated that single agent arsenic trioxide was poorly effective against hepatocellular carcinoma (HCC), which might be due to drug resistance. Methods: Mutation detection of p53 gene in arsenic trioxide resistant HCC cell lines was performed. The therapeutic effects of arsenic trioxide and Nutlin-3 on HCC were evaluated both in vitro and in vivo. A series of experiments including MTT, apoptosis assays, co-Immunoprecipitation, siRNA transfection, lentiviral infection, cell migration, invasion, and epithelial-mesenchy-mal transition (EMT) assays were performed to investigate the underlying mechanisms. Results: The acquisition of p53 mutation contributed to arsenic trioxide resistance and enhanced metastatic potential of HCC cells. Mutant p53 (Mutp53) silence could re-sensitize HCC resistant cells to arsenic trioxide and inhibit the metastatic activities, while mutp53 overexpression showed the opposite effects. Neither arsenic trioxide nor Nutlin-3 could exhibit obvious effects against arsenic trioxide resistant HCC cells, while combination of them showed significant effects. Nutlin-3 can not only increase the intracellular arsenicals through inhibition of p-gp but also promote the p73 activation and mutp53 degradation mediated by arsenic trioxide. In vivo experiments indicated that Nutlin-3 can potentiate the antitumor activities of arsenic trioxide in an orthotopic hepatic tumor model and inhibit the metastasis to lung. Conclusions: Acquisitions of p53 mutations contributed to the resistance of HCC to arsenic trioxide. Nutlin-3 could overcome arsenic trioxide resistance and inhibit tumor metastasis through p73 activation and promoting mutant p53 degradation mediated by arsenic trioxide.

A prospective cohort study of the association between drinking water arsenic exposure and self-reported maternal health symptoms during pregnancy in Bangladesh

Kile, Molly L; Rodrigues, Ema G; Mazumdar, Maitreyi; Dobson, Christine B; Diao, Nancy; Golam, Mostofa; Quamruzzaman, Quazi; Rahman, Mahmudar; Christiani, David C
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
37.2%
Background: Arsenic, a common groundwater pollutant, is associated with adverse reproductive health but few studies have examined its effect on maternal health. Methods: A prospective cohort was recruited in Bangladesh from 2008–2011 (N = 1,458). At enrollment (<16 weeks gestational age [WGA]), arsenic was measured in personal drinking water using inductively-coupled plasma mass spectrometry. Questionnaires collected health data at enrollment, at 28 WGA, and within one month of delivery. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CI) for self-reported health symptoms were estimated for each arsenic quartile using logistic regression. Results: Overall, the mean concentration of arsenic was 38 μg/L (Standard deviation, 92.7 μg/L). A total of 795 women reported one or more of the following symptoms during pregnancy (cold/flu/infection, nausea/vomiting, abdominal cramping, headache, vaginal bleeding, or swollen ankles). Compared to participants exposed to the lowest quartile of arsenic (≤0.9 μg/L), the aOR for reporting any symptom during pregnancy was 0.62 (95% CI = 0.44-0.88) in the second quartile, 1.83 (95% CI = 1.25-2.69) in the third quartile, and 2.11 (95% CI = 1.42-3.13) in the fourth quartile where the mean arsenic concentration in each quartile was 1.5 μg/L...

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

Mazumdar, Maitreyi; Ibne Hasan, Md Omar Sharif; Hamid, Rezina; Valeri, Linda; Paul, Ligi; Selhub, Jacob; Rodrigues, Ema G; Silva, Fareesa; Mia, Selim; Mostofa, Md Golam; Quamruzzaman, Quazi; Rahman, Mahmuder; Christiani, David C
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
37.16%
Background: Arsenic induces neural tube defects in several animal models, but its potential to cause neural tube defects in humans is unknown. Our objective was to investigate the associations between maternal arsenic exposure, periconceptional folic acid supplementation, and risk of posterior neural tube defect (myelomeningocele) among a highly exposed population in rural Bangladesh. Methods: We performed a case–control study that recruited physician-confirmed cases from community health clinics served by Dhaka Community Hospital in Bangladesh, as well as local health facilities that treat children with myelomeningocele. Controls were selected from pregnancy registries in the same areas. Maternal arsenic exposure was estimated from drinking water samples taken from wells used during the first trimester of pregnancy. Periconceptional folic acid use was ascertained by self-report, and maternal folate status was further assessed by plasma folate levels measured at the time of the study visit. Results: Fifty-seven cases of myelomeningocele were identified along with 55 controls. A significant interaction was observed between drinking water inorganic arsenic and periconceptional folic acid use. As drinking water inorganic arsenic concentrations increased from 1 to 25 μg/L...

The Effect of Iron Oxide Nanoparticles on the Fate and Transformation of Arsenic in Aquatic Environments

Dickson, Dionne
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
37.19%
Iron oxides and arsenic are prevalent in the environment. With the increase interest in the use of iron oxide nanoparticles (IONPs) for contaminant remediation and the high toxicity of arsenic, it is crucial that we evaluate the interactions between IONPs and arsenic. The goal was to understand the environmental behavior of IONPs in regards to their particle size, aggregation and stability, and to determine how this behavior influences IONPs-arsenic interactions. A variety of dispersion techniques were investigated to disperse bare commercial IONPs. Vortex was able to disperse commercial hematite nanoparticles into unstable dispersions with particles in the micrometer size range while probe ultrasonication dispersed the particles into stable dispersions of nanometer size ranges for a prolonged period of time. Using probe ultrasonication and vortex to prepare IONPs suspensions of different particle sizes, the adsorption of arsenite and arsenate to bare hematite nanoparticles and hematite aggregates were investigated. To understand the difference in the adsorptive behavior, adsorption kinetics and isotherm parameters were determined. Both arsenite and arsenate were capable of adsorbing to hematite nanoparticles and hematite aggregates but the rate and capacity of adsorption is dependent upon the hematite particle size...

Arsenic transport by zebrafish aquaglyceroporins

Hamdi, Mohamad; Sanchez, Marco A.; Beene, Lauren C.; Liu, Qianyong; Landfear, Scott M.; Rosen, Barry P.; Liu, Zijuan
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
37.2%
Background Arsenic is one of the most ubiquitous toxins and endangers the health of tens of millions of humans worldwide. It is a mainly a water-borne contaminant. Inorganic trivalent arsenic (AsIII) is one of the major species that exists environmentally. The transport of AsIII has been studied in microbes, plants and mammals. Members of the aquaglyceroporin family have been shown to actively conduct AsIII and its organic metabolite, monomethylarsenite (MAsIII). However, the transport of AsIII and MAsIII in in any fish species has not been characterized. Results In this study, five members of the aquaglyceroporin family from zebrafish (Danio rerio) were cloned, and their ability to transport water, glycerol, and trivalent arsenicals (AsIII and MAsIII) and antimonite (SbIII) was investigated. Genes for at least seven aquaglyceroporins have been annotated in the zebrafish genome project. Here, five genes which are close homologues to human AQP3, AQP9 and AQP10 were cloned from a zebrafish cDNA preparation. These genes were namedaqp3, aqp3l, aqp9a, aqp9b and aqp10 according to their similarities to the corresponding human AQPs. Expression of aqp9a, aqp9b, aqp3, aqp3l and aqp10 in multiple zebrafish organs were examined by RT-PCR. Our results demonstrated that these aquaglyceroporins exhibited different tissue expression. They are all detected in more than one tissue. The ability of these five aquaglyceroporins to transport water...

The effect of arsenic mitigation interventions on disease burden in Bangladesh

Lokuge, Kamalini M.; Smith, Wayne T; Caldwell, Bruce; Dear, Keith; Milton, Abdul
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Journal article; Published Version Formato: 6 pages
Relevância na Pesquisa
37.16%
Many interventions have been advocated to mitigate the impact of arsenic contamination of drinking water in Bangladesh. However, there are few data on the true magnitude of arsenic-related disease in Bangladesh nationally. There has also been little consideration given to possible adverse effects of such interventions, in particular, diarrheal disease. The purpose of this study was to estimate and compare the likely impacts of arsenic mitigation interventions on both arsenic-related disease and water-borne infectious disease. We found that arsenic-related disease currently results in 9,136 deaths per year and 174,174 disability-adjusted life years (DALYs ; undiscounted) lost per year in those exposed to arsenic concentrations > 50 µg/L. This constitutes 0.3% of the total disease burden in Bangladesh in terms of undiscounted DALYs. We found intervention to be of overall benefit in reducing disease burden in most scenarios examined, but the concomitant increase in water-related infectious disease significantly reduced the potential benefits gained from intervention. A minimum reduction in arsenic-related DALYs of 77% was necessary before intervention achieved any reduction in net disease burden. This is assuming that interventions were provided to those exposed to > 50 µg/L and would concomitantly result in a 20% increase in water-related infectious disease in those without access to adequate sanitation. Intervention appears to be justified for those populations exposed to high levels of arsenic...

Acute and chronic arsenic toxicity

Ratnaike, Ranjit Nihal
Fonte: BMJ Publishing Group Publicador: BMJ Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
Relevância na Pesquisa
37.18%
Arsenic toxicity is a global health problem affecting many millions of people. Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water and may also occur from mining and other industrial processes. Arsenic is present as a contaminant in many traditional remedies. Arsenic trioxide is now used to treat acute promyelocytic leukaemia. Absorption occurs predominantly from ingestion from the small intestine, though minimal absorption occurs from skin contact and inhalation. Arsenic exerts its toxicity by inactivating up to 200 enzymes, especially those involved in cellular energy pathways and DNA synthesis and repair. Acute arsenic poisoning is associated initially with nausea, vomiting, abdominal pain, and severe diarrhoea. Encephalopathy and peripheral neuropathy are reported. Chronic arsenic toxicity results in multisystem disease. Arsenic is a well documented human carcinogen affecting numerous organs. There are no evidence based treatment regimens to treat chronic arsenic poisoning but antioxidants have been advocated, though benefit is not proven. The focus of management is to reduce arsenic ingestion from drinking water and there is increasing emphasis on using alternative supplies of water.; http://pmj.bmj.com/cgi/content/abstract/79/933/391; © 2003 Fellowship of Postgraduate Medicine

In vivo assessment of arsenic bioavailability in rice and its significance for human health risk assessment

Juhasz, A.; Smith, E.; Weber, J.; Rees, M.; Rofe, A.; Kuchel, T.; Sansom, L.; Naidu, R.
Fonte: U.S. Dept of Health and Human Services Public Health Science Publicador: U.S. Dept of Health and Human Services Public Health Science
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
37.24%
BACKGROUND: Millions of people worldwide consume arsenic-contaminated rice; however, little is known about the uptake and bioavailability of arsenic species after arsenic-contaminated rice ingestion. OBJECTIVES: In this study, we assessed arsenic speciation in greenhouse-grown and supermarket-bought rice, and determined arsenic bioavailability in cooked rice using an in vivo swine model. RESULTS: In supermarket-bought rice, arsenic was present entirely in the inorganic form compared to greenhouse-grown rice (using irrigation water contaminated with sodium arsenate), where most (approximately 86%) arsenic was present as dimethylarsinic acid (organic arsenic). Because of the low absolute bioavailability of dimethylarsinic acid and the high proportion of dimethylarsinic acid in greenhouse-grown rice, only 33 +/- 3% (mean +/- SD) of the total rice-bound arsenic was bioavailable. Conversely, in supermarket-bought rice cooked in water contaminated with sodium arsenate, arsenic was present entirely in the inorganic form, and bioavailability was high (89 +/- 9%). CONCLUSIONS: These results indicate that arsenic bioavailability in rice is highly dependent on arsenic speciation, which in turn can vary depending on rice cultivar, arsenic in irrigation water...

Arsenic interactions with lipid particles containing iron

Rahman, M.; Rahman, F.; Sansom, L.; Naidu, R.; Schmidt, O.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
Relevância na Pesquisa
37.19%
While arsenic is toxic to all multicellular organisms, some organisms become tolerant by an unknown mechanism. We have recently uncovered an inducible tolerance mechanism in insects, which is based on a sequestration of toxins and pathogens by lipid particles. To examine whether arsenic interacts with lipid particles from mammals we compared binding of arsenic to lipid particles from insect and pig plasma after separation of lipid particles by low-density gradient centrifugation. Arsenic was found in both organisms in an area of the gradient, which corresponds to lipid-rich lipid particles. Since iron is known to affect arsenic toxicity in some organisms, we asked whether iron may be present in lipid particles. When low density cell (LDC) gradient fractions were analysed for the presence of iron we detected a peak in very low-density fractions similar to those that carried arsenic. This could indicate that arsenic interacts with lipid particles that contain iron and, if arsenic is removed from the plasma by lipid particles, that would also reduce iron-containing lipid particles at the time of arsenic emergence in the plasma. To test this assumption we measured the iron content in plasma at various time periods after the toxin ingestion. This time course revealed that iron is depleted in plasma fractions when arsenic shows a peak. Our data suggest that arsenic interacts with invertebrate and vertebrate lipid particles that are associated with proteins that may lead to detoxification by cell-free or cellular sequestration mechanisms.; Mahbub M. Rahman...

Estudo in vivo (Mus musculus) e post mortem (Globicephala melas) da exposição ao arsênio, sua distribuição tecidual e aplicação de ferramentas analíticas para especiação química; In vivo (Mus musculus) and post mortem (Globicephala melas) study of chronic exposure to arsenic, tissue distribution and aplication of analytical techniques for arsenic speciation

Souza, Juliana Maria Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/10/2014 PT
Relevância na Pesquisa
37.24%
O arsênio é um elemento químico tóxico encontrado na natureza em várias formas químicas. Entretanto, cada uma delas apresenta diferença na toxicocinética e toxicodinâmica. Os alimentos são considerados a principal fonte de exposição pelos humanos, destacando o arroz, que pode conter o arsênio na forma inorgânica e nas formas de ácidos monometilarsônico e dimetilarsínico (DMA), e alimentos de origem marinha. Os compostos de arsênio encontrados na biota marinha são classificados como solúveis em água, como arsenobetaína e arsenoaçúcares, e solúveis em lipídeos como os arsenolipídeos. Assim, é importante o desenvolvimento de estudos que avaliem a exposição ao arsênio pela alimentação, sua distribuição em organismos e sua especiação química. Neste sentido, o presente trabalho está apresentado em dois capítulos. O capítulo I corresponde ao estudo de exposição crônica em camudongos machos Swiss ao arsênio presente na dieta e os efeitos em alguns parâmetros bioquímicos. Para isso os animais foram divididos em grupo controle, três grupos expostos à dieta contendo arroz naturalmente contaminado com arsênio e três grupos expostos à dieta preparada com sais de arsênio nas mesmas concentrações presentes no arroz. Concentrações de arsênio total foram determinadas nos tecidos dos animais em estudo por ICP-MS...

Arsenic speciation in rice and fish using HPLC-ICP-MS

Coelho, Inês; Gueifão, Sandra; Castanheira, Isabel
Fonte: Instituto Nacional de Saúde Doutor Ricardo Jorge, IP Publicador: Instituto Nacional de Saúde Doutor Ricardo Jorge, IP
Tipo: Conferência ou Objeto de Conferência
Publicado em /01/2012 ENG
Relevância na Pesquisa
37.18%
Chemical speciation in foodstuffs is of uttermost importance since it is nowadays recognized that both toxicity and bioavailability of an element depend on the chemical form in which the element is present. Regarding arsenic, inorganic species are classified as carcinogenic while organic arsenic, such as arsenobetaine (AsB) or arsenocholine (AsC), is considered less toxic or even non-toxic. Coupling a High Performance Liquid Chromatographer (HPLC) with an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) combines the power of separation of the first with the selectivity and sensitivity of the second. The present work aims at developing a method, using HPLC-ICP-MS technique, to identify and quantify the chemical species of arsenic present in two food matrices, rice and fish. Two extraction methods, ultrasound and microwave, and several conditions were studied. The best method was chosen based on recovery percentages. To ensure that no interconversion of species was occurring, individual spikes of each species of arsenic were made in both matrices and recovery rates were calculated. To guaranty accurate results reference material BCR-627 TUNA FISH, containing certified values for AsB and DMA, was analyzed. Chromatographic separation was achieved using an anion exchange column...

Arsenic biotransformations in terrestrial organisms: A study of the transport and transformation of arsenic in plants, fungi, fur and feathers, using conventional speciation analysis and X-ray absorption spectroscopy

Smith, Paula Graham
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado Formato: 997670 bytes; application/pdf
EN
Relevância na Pesquisa
37.26%
Arsenic taken up by plants and fungi from contaminated soils can subsequently be introduced into food chains. Given the toxic properties of some arsenic compounds, this may be a cause for concern. Much remains to be learned about how these compounds are transformed and distributed in terrestrial organisms. Radishes, white button mushrooms, fur, and feather samples were thus investigated to gain a better understanding of arsenic biotransformations in terrestrial organisms. In this study, we utilized two analytical techniques for the detection and identification of arsenic compounds (“arsenic speciation analysis”). High performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) provided a highly sensitive method for detecting low levels (ng•g-1) of methanol:water extractable arsenic compounds. X-ray absorption spectroscopy (XAS) techniques provided direct arsenic speciation analysis of tissues, resulting in a more representative arsenic profile of the original organisms, without the need to extract arsenic first. Overall, the results for speciation analysis underline the complementary nature of the HPLC-ICP-MS and XAS techniques. Mushrooms contained organic arsenic compounds which were not identified in the radish. In particular arsenobetaine (AB)...

Effect of biosolid incorporation on arsenic distribution in Mollisol soils in central Chile

Richter D., Pablo; Ahumada Torres, Aída Inés de Lourdes; Ascar Estay, María Loreto
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artículo de revista
EN
Relevância na Pesquisa
37.19%
The effect of biosolid incorporation on arsenic distribution in Mollisol soils in central Chile was studied. Two soils were sequentially extracted for arsenic with a five-step method that accounts for the following arsenic forms: non-specifically adsorbed (F1), specifically adsorbed (F2), amorphous and poorly crystallized Fe and Al oxides (H), well-crystallized Fe and Al oxides (F4) and residual (F5). The arsenic residual fraction was predominant in Pintue soil, whereas in Graneros soil, arsenic was mostly associated to amorphous Fe and Al oxides. Graneros soil exhibited a higher As(V) adsorbing capacity than Pintue soil, which relates to the higher clay and iron and aluminum oxides contents, confirming that these components participation is essential for the adsorption of this metalloid. Biosolid application at a rate of 100 Mg ha(-1) caused an increase in arsenic bound to amorphous Fe and Al oxides and in the residual fraction, in Pintue soil. When Pintue soil was spiked with arsenic, aged for two months, and treated with biosolid (100 Mg ha(-1)), the content of arsenic in the most labile fractions decreased, thus showing a favorable effect in its application to soils with few specific sites for arsenic adsorption. Arsenic speciation was carried out in the first two fractions of the sequential extraction procedure. As(V) was the main form in both fractions. Biosolid incorporation at a rate of 100 ha(-1) hat caused a significant increase in organic arsenic forms.

Association between nutritional status and arsenicosis due to chronic arsenic exposure in Bangladesh

Milton, Abdul; Hasan, Ziaul; Shahidullah, S M; Sharmin, Sinthia; Jakariya, M; Rahman, Mohammad; Dear, Keith; Smith, Wayne T
Fonte: Carfax Publishing, Taylor & Francis Group Publicador: Carfax Publishing, Taylor & Francis Group
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
37.18%
The role of nutritional factors in arsenic metabolism and toxicity is not clear. Provision of certain low protein diets resulted in decreased excretion of DMA and increased tissue retention of arsenic in experimental studies. This paper reports a prevalence comparison study conducted in Bangladesh to assess the nutritional status among the chronic arsenic exposed and unexposed population. 138 exposed individuals diagnosed as arsenicosis patients were selected from three known arsenic endemic villages of Bangladesh and age, sex matched 144 unexposed subjects were randomly selected from three arsenic free villages. The mean arsenic concentration in drinking water for the exposed and unexposed population was 641.15 and 13.5 μg L-1 respectively. Body Mass Index was found to be lower than 18.5, the cut off point for malnutrition, in 57 (41.31%) out of 138 exposed arsenicosis cases and 31 (21.53%) out of 144 unexposed individuals. The crude prevalence ratio (or risk) was 1.92 (95% CI = 1.33-2.78) for poor nutritional status among the arsenicosis cases compared to the unexposed population. The findings of this study add to the evidence that poor nutritional status may increase an individual's susceptibility to chronic arsenic toxicity, or alternatively that arsenicosis may contribute to poor nutritional status.

Intervention trial to assess arsenic exposure from food crops in Bangladesh

Ranmuthugala, Geethanjali; Milton, Abdul; Smith, Wayne T; Ng, Jack C; Sim, Malcolm R; Dear, Keith; Caldwell, Bruce
Fonte: Heldref Publications Publicador: Heldref Publications
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
37.23%
The authors assessed the contribution of food irrigated with arsenic-contaminated water to human exposure to arsenic in Bangladesh. An intervention trial was conducted in a village in the Jessore District of Bangladesh, where irrigation water had been field-tested in March 2000 and was found to contain arsenic with concentrations ranging from 100 to 500 μg/l. In May 2000, a random sample of 63 households was selected from the village, and 1 eligible person from each household was recruited to the study and randomized to an intervention or control group. The intervention group received food purchased from a village where irrigation water was found to contain <10 μg/l arsenic. The control group received food purchased from markets in the study village, where irrigation water was found to contain >100 μg/l arsenic. Pre- and postintervention urine samples were collected for urinary arsenic speciation assays. Preintervention, the mean urinary total arsenic concentrations were 139.25 μg/l and 129.15 μg/l for the intervention and control groups, respectively. These concentrations did not change significantly following intervention. Arsenic concentrations in samples of selected raw and cooked foods from the low-contamination area did not contain less arsenic than samples from the high-contamination area. Further studies to investigate the arsenic content of food grown in areas with high and low arsenic contamination of irrigation water are recommended.

Toxicity and accumulation of arsenic in wheat (Triticum aestivum L.) varieties of China

Zhang,WD; Liu,DS; Tian,JC; He,FL
Fonte: Phyton (Buenos Aires) Publicador: Phyton (Buenos Aires)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
37.25%
Soil arsenic contamination becomes a potential agricultural and environmental hazard worldwide, and has been a serious problem for safe food production. A field experiment on soil contamination was conducted on four wheat varieties (Jimai, Gaoyou, Weimai and Wennong) in Eastern China, using 50 or 100 mg arsenic/kg soil. Biomass production and yield components were determined and arsenic concentrations were measured in plant tissues. Differential arsenic effects on wheat varieties were determined at maturity. Results showed that addition of arsenic significantly (p<0.05) reduced root, stem and spike dry weight and yield components, which resulted in the decrease of grain yield per plant. Arsenic concentrations in plant tissues increased significantly (p<0.05) with treatments, and its uptake varied considerably among wheat varieties, plant tissues and arsenic treatments. Arsenic concentrations in plant tissues were as follows: roots > stems > leaves and rachises > grains > glumes > awns. In the arsenic treatments, arsenic concentrations in bran were about 2-3 times higher than those in flour. Most of the arsenic contaminated flour exceeded the Chinese tolerance limit. Arsenic contents of grain parts were dependent on variety and treatment level in polluted soils. Weimai and Wennong showed highest amounts of arsenic in flour than the other varieties at 50 or 100 mg/ kg soil treatment...

Arsenic contamination of groundwater and its health impact on residents in a village in West Bengal, India

Rahman,Mohammad Mahmudur; Sengupta,Mrinal Kumar; Ahamed,Sad; Chowdhury,Uttam Kumar; Lodh,Dilip; Hossain,Amir; Das,Bhaskar; Roy,Niladri; Saha,Kshitish Chandra; Palit,Shyamal Kanti; Chakraborti,Dipankar
Fonte: World Health Organization Publicador: World Health Organization
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2005 EN
Relevância na Pesquisa
37.23%
An in-depth study was carried out in Rajapur, an arsenic-affected village in West Bengal, India, to determine the degree of groundwater contamination with arsenic and the impact of this contamination on residents. The flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) method was used to measure arsenic concentrations in water and biological samples. Dermatologists recorded the dermatological features of arsenicosis. Out of a total of 336 hand-pumped tube-wells in Rajapur, 91% (307/336) contained arsenic at concentrations > 10 µg/l, and 63% (213/336) contained arsenic at > 50 µg/l. The type of arsenic in groundwater, the variation in concentrations of arsenic as the depth of tube-wells changed, and the iron concentration in the wells were also measured. Altogether 825 of 3500 residents were examined for skin lesions; of these, 149 had lesions caused by exposure to arsenic. Of the 420 biological samples collected and analysed, 92.6% (389) contained arsenic at concentrations that were above normal. Thus many villagers might be subclinically affected. Although five arsenic-filtering devices had been installed in Rajapur, it appears that villagers are still exposed to raised concentrations of arsenic in their drinking-water. Detailed village-level studies of arsenic-affected areas in West Bengal are required in order to understand the magnitude of contamination and its effects on people. Villagers are ill-informed about the dangers of drinking arsenic-contaminated water. The contamination could be brought under control by increasing community awareness of the dangers and implementing proper watershed management techniques that involve local people.

Contamination of drinking-water by arsenic in Bangladesh: a public health emergency

Smith,Allan H.; Lingas,Elena O.; Rahman,Mahfuzar
Fonte: World Health Organization Publicador: World Health Organization
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2000 EN
Relevância na Pesquisa
37.19%
The contamination of groundwater by arsenic in Bangladesh is the largest poisoning of a population in history, with millions of people exposed. This paper describes the history of the discovery of arsenic in drinking-water in Bangladesh and recommends intervention strategies. Tube-wells were installed to provide ‘‘pure water’’ to prevent morbidity and mortality from gastrointestinal disease. The water from the millions of tube-wells that were installed was not tested for arsenic contamination. Studies in other countries where the population has had long-term exposure to arsenic in groundwater indicate that 1 in 10 people who drink water containing 500 µg of arsenic per litre may ultimately die from cancers caused by arsenic, including lung, bladder and skin cancers. The rapid allocation of funding and prompt expansion of current interventions to address this contamination should be facilitated. The fundamental intervention is the identification and provision of arsenic-free drinking water. Arsenic is rapidly excreted in urine, and for early or mild cases, no specific treatment is required. Community education and participation are essential to ensure that interventions are successful; these should be coupled with follow-up monitoring to confirm that exposure has ended. Taken together with the discovery of arsenic in groundwater in other countries...

Arsenic in drinking water in the Los Altos de Jalisco region of Mexico

Hurtado-Jiménez,Roberto; Gardea-Torresdey,Jorge L.
Fonte: Organización Panamericana de la Salud Publicador: Organización Panamericana de la Salud
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2006 EN
Relevância na Pesquisa
37.22%
OBJECTIVE: To establish the degree of contamination by arsenic in drinking water in the Los Altos de Jalisco (LAJ) region of west-central Mexico, and to estimate the levels of exposure that residents of the area face. METHODS: Total arsenic concentration (the sum of all arsenic forms, organic and inorganic) was determined for 129 public water wells in 17 municipal capitals (cabeceras municipales) of the LAJ region, using inductively coupled plasma-optical emission spectroscopy. For most of the wells, water samples were taken in both November 2002 and October 2003. The levels of exposure to arsenic were estimated for babies (10 kg), children (20 kg), and adults (70 kg). RESULTS: Mean concentrations of arsenic higher than the Mexican national guideline value of 25 µg/L were found in 44 (34%) of the 129 wells. The mean concentration of total arsenic for the 129 wells ranged from 14.7 µg/L to 101.9 µg/L. The highest concentrations were found in well water samples collected in the cities of Mexticacán (262.9 µg/L), Teocaltiche (157.7 µg/L), and San Juan de los Lagos (113.8 µg/L). Considering the global mean concentration for all the wells in each of the 17 cities, the mean concentration of arsenic exceeded the Mexican guideline value in 7 of the cities. However...