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Sample records for arsenic source term

  1. Arsenic pollution sources.

    Science.gov (United States)

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

    2008-01-01

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

  2. Environmental source of arsenic exposure.

    Science.gov (United States)

    Chung, Jin-Yong; Yu, Seung-Do; Hong, Young-Seoub

    2014-09-01

    Arsenic is a ubiquitous, naturally occurring metalloid that may be a significant risk factor for cancer after exposure to contaminated drinking water, cigarettes, foods, industry, occupational environment, and air. Among the various routes of arsenic exposure, drinking water is the largest source of arsenic poisoning worldwide. Arsenic exposure from ingested foods usually comes from food crops grown in arsenic-contaminated soil and/or irrigated with arsenic-contaminated water. According to a recent World Health Organization report, arsenic from contaminated water can be quickly and easily absorbed and depending on its metabolic form, may adversely affect human health. Recently, the US Food and Drug Administration regulations for metals found in cosmetics to protect consumers against contaminations deemed deleterious to health; some cosmetics were found to contain a variety of chemicals including heavy metals, which are sometimes used as preservatives. Moreover, developing countries tend to have a growing number of industrial factories that unfortunately, harm the environment, especially in cities where industrial and vehicle emissions, as well as household activities, cause serious air pollution. Air is also an important source of arsenic exposure in areas with industrial activity. The presence of arsenic in airborne particulate matter is considered a risk for certain diseases. Taken together, various potential pathways of arsenic exposure seem to affect humans adversely, and future efforts to reduce arsenic exposure caused by environmental factors should be made.

  3. A global health problem caused by arsenic from natural sources

    Energy Technology Data Exchange (ETDEWEB)

    Ng, J.C.; Wang, J.P.; Shraim, A. [University of Queensland, Brisbane, Qld. (Australia). National Research Center for Environmental Toxicology

    2003-09-01

    Arsenic is a carcinogen to both humans and animals. Arsenicals have been associated with cancers of the skin, lung, and bladder. Clinical manifestations of chronic arsenic poisoning include non-cancer end point of hyper- and hypo-pigmentation, keratosis, hypertension, cardiovascular diseases and diabetes. Epidemiological evidence indicates that arsenic concentration exceeding 50 {mu}g l{sup -1} in the drinking water is not public health protective. The current WHO recommended guideline value for arsenic in drinking water is 10 {mu}g l{sup -1}, whereas many developing countries are still having a value of 50 {mu}g 1{sup -1}. It has been estimated that tens of millions of people are at risk exposing to excessive levels of arsenic from both contaminated water and arsenic-bearing coal from natural sources. The global health implication and possible intervention strategies were also discussed in this review article.

  4. Chromated copper arsenate–treated wood: a potential source of arsenic exposure and toxicity in dermatology

    Directory of Open Access Journals (Sweden)

    Amy Yuntzu-Yen Chen, MD

    2016-03-01

    Full Text Available Arsenic-contaminated drinking water presents a serious health hazard in certain geographic locations around the world. Chromated copper arsenate, a pesticide and preservative that was used to pressure treat residential lumber in the United States beginning in the 1940s and was banned by the Environmental Protection Agency in 2003, poses a potential source of arsenic exposure and toxicity. In this study, we review the clinical manifestations of arsenic intoxication with the focus on dermatologic manifestations. Dermatologists should be aware that although chromated copper arsenate-treated wood for residential use was banned in 2003, the exposure risk remains. Long-term follow up is necessary to detect arsenic induced cutaneous and visceral malignancy in patients with history of arsenic exposure.

  5. A NEW PUBLIC HEALTH ISSUE: CONTAMINATION WITH ARSENIC OF PRIVATE WATER SOURCES

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    ANCA ELENA GURZAU

    2012-03-01

    Full Text Available A new public health issue: contamination with arsenic of private water sources. Known since the early ‘40s, the natural contamination with arsenic of depth water in Bihor and Arad areas continues to incite interest, especially since the rural localities still use depth water as the main source of drinking water. Arsenic concentrations measured in the water sources in the area range between 0-176 μg/L, and it is estimated that over 45,000 people are exposed via drinking water to arsenic concentrations above 10 μg/L. The present study proposed the measurement of arsenic concentrations from old public sources and individual private water sources from recent wells located in five localities in Arad County, samples being collected during 2010-2011. The results showed that public water sources declared or not non-potable contain arsenic above the maximum allowable concentration of 10 μg/L. Individual water sources recently drilled as an alternative for the population to the lack of access to safe water from public water systems, presented high concentrations of arsenic in most cases, even higher than the concentrations of the public sources declared by authorities as non-potable. In the absence of informing and counseling the population regarding the natural uneven distribution of arsenic in the depth water and its potential carcinogenicity, human exposure continues and it is even more intense. The significance of the problem in terms of public health becomes even more important as for the private water sources quality is not monitored by the authorities according to law, water analysis being performed on request and for a fee.

  6. Distributional patterns of arsenic concentrations in contaminant plumes offer clues to the source of arsenic in groundwater at landfills

    Science.gov (United States)

    Harte, Philip T.

    2015-01-01

    The distributional pattern of dissolved arsenic concentrations from landfill plumes can provide clues to the source of arsenic contamination. Under simple idealized conditions, arsenic concentrations along flow paths in aquifers proximal to a landfill will decrease under anthropogenic sources but potentially increase under in situ sources. This paper presents several conceptual distributional patterns of arsenic in groundwater based on the arsenic source under idealized conditions. An example of advanced subsurface mapping of dissolved arsenic with geophysical surveys, chemical monitoring, and redox fingerprinting is presented for a landfill site in New Hampshire with a complex flow pattern. Tools to assist in the mapping of arsenic in groundwater ultimately provide information on the source of contamination. Once an understanding of the arsenic contamination is achieved, appropriate remedial strategies can then be formulated.

  7. Long-term arsenic monitoring with an Enterobacter cloacae microbial fuel cell.

    Science.gov (United States)

    Rasmussen, Michelle; Minteer, Shelley D

    2015-12-01

    A microbial fuel cell was constructed with biofilms of Enterobacter cloacae grown on the anode. Bioelectrocatalysis was observed when the biofilm was grown in media containing sucrose as the carbon source and methylene blue as the mediator. The presence of arsenic caused a decrease in bioelectrocatalytic current. Biofilm growth in the presence of arsenic resulted in lower power outputs whereas addition of arsenic showed no immediate result in power output due to the short term arsenic resistance of the bacteria and slow transport of arsenic across cellular membranes to metabolic enzymes. Calibration curves plotted from the maximum current and maximum power of power curves after growth show that this system is able to quantify both arsenate and arsenate with low detection limits (46 μM for arsenate and 4.4 μM for arsenite). This system could be implemented as a method for long-term monitoring of arsenic concentration in environments where arsenic contamination could occur and alter the metabolism of the organisms resulting in a decrease in power output of the self-powered sensor.

  8. Long-term consequences of arsenic poisoning during infancy due to contaminated milk powder

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    Grandjean Philippe

    2006-10-01

    Full Text Available Abstract Arsenic toxicity is a global health problem affecting many millions of people. The main source of exposure is drinking water contaminated by natural geological sources. Current risk assessment is based on the recognized carcinogenicity of arsenic, but neurotoxic risks have been overlooked. In 1955, an outbreak of arsenic poisoning occurred among Japanese infants, with more than 100 deaths. The source was contaminated milk powder produced by the Morinaga company. Detailed accounts of the Morinaga dried milk poisoning were published in Japanese only, and an overview of this poisoning incident and its long-term consequences is therefore presented. From analyses available, the arsenic concentration in milk made from the Morinaga milk powder is calculated to be about 4–7 mg/L, corresponding to daily doses slightly above 500 μg/kg body weight. Lower exposures would result from using diluted milk. Clinical poisoning cases occurred after a few weeks of exposure, with a total dose of about 60 mg. This experience provides clear-cut evidence for hazard assessment of the developmental neurotoxicity. At the present time, more than 600 surviving victims, now in their 50s, have been reported to suffer from severe sequelae, such as mental retardation, neurological diseases, and other disabilities. Along with more recent epidemiological studies of children with environmental arsenic exposures, the data amply demonstrate the need to consider neurotoxicity as a key concern in risk assessment of inorganic arsenic exposure.

  9. Arsenic

    Science.gov (United States)

    Arsenic is a natural element found in soil and minerals. Arsenic compounds are used to preserve wood, as pesticides, and in some industries. Arsenic can get into air, water, and the ground from wind- ...

  10. Removal of arsenic from contaminated water sources by sorption onto iron-oxide-coated polymeric materials.

    Science.gov (United States)

    Katsoyiannis, Ioannis A; Zouboulis, Anastasios I

    2002-12-01

    The modification of polymeric materials (polystyrene and polyHIPE) by coating their surface with appropriate adsorbing agents (i.e. iron hydroxides) was investigated in the present work, in order to apply the modified media in the removal of inorganic arsenic anions from contaminated water sources. The method, termed adsorptive filtration, has been classified as an emerging technology in water treatment processes as it presents several advantages towards conventional technologies: the production of high amounts of toxic sludge can be avoided and it is considered as economically more efficient; whereas it has not yet been applied in full-scale treatment plants for low-level arsenic removal. The present experiments showed that both modified media were capable in removing arsenic from the aqueous stream, leading to residual concentration of this toxic metalloid element below 10 microg/L, which is the new maximum concentration limit set recently by the European Commission and imposed by the USEPA. Though, among the examined materials, polyHIPE was found to be more effective in the removal of arsenic, as far as it concerns the maximum sorptive capacity before the filtration bed reaches the respective breakthrough point.

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

    Science.gov (United States)

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

    2007-07-01

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

  12. Quantitative imaging of arsenic and its species in goat following long term oral exposure.

    Science.gov (United States)

    Patra, Pabitra Hriday; Bandyopadhyay, Samiran; Kumar, Rakesh; Datta, Bakul Kumar; Maji, Chinmoy; Biswas, Suman; Dash, Jeevan Ranjan; Sar, Tapas Kumar; Sarkar, Samar; Manna, Sanjib K; Chakraborty, Animesh Kumar; Mandal, Tapan Kumar

    2012-06-01

    Severity of arsenic toxicity was reported to vary depending on its species. The present study reflects the status of different species of arsenic in goat following long-term exposure of arsenic leading to hepatic damage. The experiment was conducted with six black Bengal goats, which were administered with sodium arsenite orally at a dose rate of 2 mgkg(-1) daily for 84 days. Faeces, urine, hair and blood samples were collected from those animals at 14 days interval. Excretion of total arsenic was reduced from 56 days onwards through both faeces and urine indicating higher accumulation of arsenic in body. The speciation study revealed that urinary arsenic was mainly of organic type, whereas hair accumulated almost equal proportion of arsenite, arsenate and organo arsenicals. Goats excreted high proportion of organo arsenicals through faeces possibly due to hepatobiliary secretion of organo arsenic into the gut. Significantly elevated serum alanine aminotransferase and aspartate aminotransferase activities (pgoat. The study thus alluded that the toxicity of arsenic would aggravate if the animals were exposed for long time as the hepatotoxicity progressed resulting in decreased methylation and formation of organo arsenicals and decreased excretions through urine. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Study of Arsenic Presence in Drinking Water Sources: A Case Study

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    Z Kamali

    2008-09-01

    Full Text Available Background and Objectives: Conducted studies about arsenic have shown that consumption of water contaminated with arsenic can causes different adverse health effects in consumers. World Health Organization (WHO has enacted 10µg/L arsenic in drinking water as a guideline value. Regarding some reports about arsenic presence in a village of Hashtrood county and related health effects and also considering this fact that determination of arsenic as a poisoning chemical is not included in routine monitoring of water by responsible organizations, in present study all of drinking water sources in Hashtrood county in East Azerbaijan province were studied for arsenic presence."nMaterials and Methods: Water supply and its sanitation situation were studied in all of cities and residential villages (200 villages by field visiting. Arsenic content of water samples were determined using Ez arsenic test kit, a product of Hach Company. For assurance of the kit results, 20 water samples with different concentration of arsenic were analyzed using Inductively Coupled Plasma (ICP method and then achieved results was compared together."nResults: Arsenic was present in drinking water of 50 villages that in 9 villages its level was higher than Iranian standard (50µg/L. During the study totally 11087 persons (21.96% of rural areas population in Hashtrood county were exposed to different levels of arsenic via drinking water. Correlation between kit and ICP results was significant (R2 = 0.9715"nConclusion: Studied region in present study is a polluted area to arsenic by geogenic sources. It is necessary to replace water source of villages with higher level than national standard with safe drinking water. Annually measurement of arsenic in drinking water of all villages spatially polluted villages should be considered by responsible organization e.g. Health Network and Rural Water and Wastewater Company. Used kit in our study is recommendable for this purpose.

  14. Arsenic

    Science.gov (United States)

    ... WHO Language عربي 中文 English Français Русский Español Media centre Menu Media centre News News releases Previous ... this water and eating food irrigated with arsenic-rich water, can lead to chronic arsenic poisoning. Skin ...

  15. Distribution and hosts of arsenic in a sediment core from the Chianan Plain in SW Taiwan: Implications on arsenic primary source and release mechanisms.

    Science.gov (United States)

    Yang, Huai-Jen; Lee, Chi-Yu; Chiang, Yu-Ju; Jean, Jiin-Shuh; Shau, Yen-Hong; Takazawa, Eiichi; Jiang, Wei-Teh

    2016-11-01

    High arsenic abundance of 50-700μg/L in the groundwater from the Chianan Plain in southwestern Taiwan is a well-known environmental hazard. The groundwater-associated sediments, however, have not been geochemically characterized, thus hindering a comprehensive understanding of arsenic cycling in this region. In this study, samples collected from a 250m sediment core at the centre of the Chianan Plain were analyzed for arsenic and TOC concentrations (N=158), constituent minerals (N=25), major element abundances (N=105), and sequential arsenic extraction (N=23). The arsenic data show a prevalence of >10mg/kg with higher concentrations of 20-50mg/kg concentrated at 60-80 and 195-210m. Arsenic was extracted mainly as an adsorbate on clay minerals, as a co-precipitate in amorphous iron oxyhydroxide, and as a structural component in clay minerals. Since the sediments consist mainly of quartz, chlorite, and illite, the correlations between arsenic concentration and abundances of K2O and MgO pinpoint illite and chlorite as the major arsenic hosts. The arsenic-total iron correlation reflects the role of chlorite along with the contribution from amorphous iron oxyhydroxide as indicated by arsenic extraction data. Organic matter is not the dominant arsenic host for low TOC content, low arsenic abundance extracted from it, and a relatively low R(2) of the arsenic-TOC correlation. The major constituent minerals in the sediments are the same as those of the upriver metapelites, establishing a sink-source relationship. Composition data from two deep groundwater samples near the sediment core show Eh values and As(V)/As(III) ratios of reducing environments and high arsenic, K, Mg, and Fe contents necessary for deriving arsenic from sediments by desorption from clay and dissolution of iron oxyhydroxide. Therefore, groundwater arsenic was mainly derived from groundwater-associated sediments with limited contributions from other sources, such as mud volcanoes.

  16. Release of accumulated arsenic from distribution pipes into tap water after arsenic treatment of source water- presentation

    Science.gov (United States)

    Toxic arsenic (As) is known to incorporate from source well water onto the scales of distribution system pipes such as iron, copper, galvanized steel and even plastic containing internal buildup of iron coatings (Lytle et al., 2010, 2004; Schock, 2015; Reiber and Dostal, 2000). W...

  17. Speciation and Source Identification for Arsenic in the Southern High Plains Aquifer

    Science.gov (United States)

    Venkataraman, K.; Rainwater, K.; Jackson, W. A.; Ridley, M. K.

    2009-12-01

    Significant levels of arsenic have been detected in the groundwater of the Southern High Plains. The potential sources include atmospheric deposition, the use of agricultural defoliants and natural subsurface geochemical interactions. To identify the source of arsenic, groundwater and soil samples were collected by the Texas Tech University Water Resources Center from sites spread over 18 counties in the West Texas region. Arsenic and its inorganic species were quantified along with commonly occurring and related cations and anions such as iron, manganese, copper and sulfate. Correlation studies were conducted to understand the variation of arsenical species with related parameters. A geochemical modeling tool, MINTEQ was used to predict the speciation of arsenic and compare these results with lab analyses. Sensitivity analysis was also conducted with MINTEQ to study the behavior of arsenical species with variations in total iron and field parameters such as pH, ORP, and DO. The distribution of arsenic and its species in the soil profiles tested indicated a positive correlation with depth. The highest concentrations were found close to the water table while the upper soil layers had low to non-detect concentrations. In the groundwater samples, arsenic concentration and speciation varied significantly between sites. As (III) was found to be the dominant species in the majority (>80%) of the samples. MINTEQ speciation forecasts compared favorably with a majority of the groundwater analyses. Sensitivity analyses indicated a negative correlation between As(III) and ORP, while increasing iron concentration increased the levels of As(III). Decreasing iron caused no significant change in the concentration of As(III). Low concentrations of arsenic in the shallow layers of the soil have led to the elimination of atmospheric deposition and the use of defoliants as potential sources of contamination. The combination of analytical results and the geochemical simulations

  18. Health burden of skin lesions at low arsenic exposure through groundwater in Pakistan. Is river the source?

    Science.gov (United States)

    Fatmi, Zafar; Azam, Iqbal; Ahmed, Faiza; Kazi, Ambreen; Gill, Albert Bruce; Kadir, Muhmmad Masood; Ahmed, Mubashir; Ara, Naseem; Janjua, Naveed Zafar

    2009-07-01

    A significant proportion of groundwater in south Asia is contaminated with arsenic. Pakistan has low levels of arsenic in groundwater compared with China, Bangladesh and India. A representative multi-stage cluster survey conducted among 3874 persons > or = 15 years of age to determine the prevalence of arsenic skin lesions, its relation with arsenic levels and cumulative arsenic dose in drinking water in a rural district (population: 1.82 million) in Pakistan. Spot-urine arsenic levels were compared among individuals with and without arsenic skin lesions. In addition, the relation of age, body mass index, smoking status with arsenic skin lesions was determined. The geographical distribution of the skin lesions and arsenic-contaminated wells in the district were ascertained using global positioning system. The total arsenic, inorganic and organic forms, in water and spot-urine samples were determined by atomic absorption spectrophotometry. The prevalence of skin lesions of arsenic was estimated for complex survey design, using surveyfreq and surveylogistic options of SAS 9.1 software.The prevalence of definitive cases i.e. hyperkeratosis of both palms and soles, was 3.4 per 1000 and suspected cases i.e. any sign of arsenic skin lesions (melanosis and/or keratosis), were 13.0 per 1000 among > or = 15-year-old persons in the district. Cumulative arsenic exposure (dose) was calculated from levels of arsenic in water and duration of use of current drinking water source. Prevalence of skin lesions increases with cumulative arsenic exposure (dose) in drinking water and arsenic levels in urine. Skin lesions were 2.5-fold among individuals with BMI Pakistan. Further investigations and focal mitigation measures for arsenic may be carried out alongside Indus River.

  19. Long-Term Exposure to Low-Level Arsenic in Drinking Water and Diabetes Incidence

    DEFF Research Database (Denmark)

    Bräuner, Elvira V; Nordsborg, Rikke B; Andersen, Zorana Jovanovic

    2014-01-01

    BACKGROUND: Established causes of diabetes do not fully explain the epidemic. High level arsenic exposure has been implicated in diabetes risk but the effect of low-level arsenic exposure in drinking water remains unclear. OBJECTIVE: To determine if long-term exposure to low-level arsenic...... in drinking water in Denmark is associated with increased risk of diabetes using a large prospective cohort. METHODS: During 1993-1997 we recruited 57,053 persons. We followed each cohort member for diabetes occurrence from enrollment until 31 December 2006. We traced and geocoded residential addresses......, and 3,035 (5.8%) cases of diabetes based on a stricter definition. The adjusted incidence rate ratio's per 1 µg/L increment in arsenic levels in drinking water were (IRR = 1.03; 95% CI: 1.01, 1.06) and (IRR = 1.02; 95% CI: 0.99, 1.05) for all and strict diabetes cases, respectively. CONCLUSIONS: Long...

  20. Source of arsenic-bearing pyrite in southwestern Vermont, USA: sulfur isotope evidence.

    Science.gov (United States)

    Mango, Helen; Ryan, Peter

    2015-02-01

    Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ(34)S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to >2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from -5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in (34)S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ(34)S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ(34)S values.

  1. Naturally occurring arsenic in groundwater and identification of the geochemical sources in the Duero Cenozoic Basin, Spain

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    Gómez, J. J.; Lillo, J.; Sahún, B.

    2006-09-01

    Arsenic concentrations surpassing potability limit of 10 μg/L in the groundwater supplies of an extensive area in the Duero Cenozoic Basin (central Spain) have been detected and the main sources of arsenic identified. Arsenic in 514 samples of groundwater, having mean values of 40.8 μg/L, is natural in origin. Geochemical analysis of 553 rock samples, assaying arsenic mean values of 23 mg/kg, was performed. Spatial coincidence between the arsenic anomaly in groundwater and the arsenic lithogeochemical distribution recorded in the Middle Miocene clayey organic-rich Zaratan facies illustrates that the rocks of this unit are the main source of arsenic in groundwater. The ferricretes associated to the Late Cretaceous-Middle Miocene siliciclastics also constitute a potential arsenic source. Mineralogical study has identified the presence of arsenic in iron oxides, authigenic pyrite, manganese oxides, inherited titanium-iron oxides, phyllosilicates and organomineral compounds. Arsenic mobilization to groundwater corresponds to arsenic desorption from iron and manganese oxides and from organic matter.

  2. In utero and early life arsenic exposure in relation to long-term health and disease

    Energy Technology Data Exchange (ETDEWEB)

    Farzan, Shohreh F.; Karagas, Margaret R. [Children' s Environmental Health and Disease Prevention Research Center at Dartmouth, Hanover, NH 03755 (United States); Section of Biostatistics and Epidemiology, Department of Community and Family Medicine and Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756 (United States); Chen, Yu, E-mail: yu.chen@nyumc.org [Department of Population Health, New York University School of Medicine, New York, NY 10016 (United States)

    2013-10-15

    Background: There is a growing body of evidence that prenatal and early childhood exposure to arsenic from drinking water can have serious long-term health implications. Objectives: Our goal was to understand the potential long-term health and disease risks associated with in utero and early life exposure to arsenic, as well as to examine parallels between findings from epidemiological studies with those from experimental animal models. Methods: We examined the current literature and identified relevant studies through PubMed by using combinations of the search terms “arsenic”, “in utero”, “transplacental”, “prenatal” and “fetal”. Discussion: Ecological studies have indicated associations between in utero and/or early life exposure to arsenic at high levels and increases in mortality from cancer, cardiovascular disease and respiratory disease. Additional data from epidemiologic studies suggest intermediate effects in early life that are related to risk of these and other outcomes in adulthood. Experimental animal studies largely support studies in humans, with strong evidence of transplacental carcinogenesis, atherosclerosis and respiratory disease, as well as insight into potential underlying mechanisms of arsenic's health effects. Conclusions: As millions worldwide are exposed to arsenic and evidence continues to support a role for in utero arsenic exposure in the development of a range of later life diseases, there is a need for more prospective studies examining arsenic's relation to early indicators of disease and at lower exposure levels. - Highlights: • We review in utero and early-life As exposure impacts on lifelong disease risks. • Evidence indicates that early-life As increases risks of lung disease, cancer and CVD. • Animal work largely parallels human studies and may lead to new research directions. • Prospective studies and individual exposure assessments with biomarkers are needed. • Assessing intermediary

  3. Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

    Energy Technology Data Exchange (ETDEWEB)

    Mango, Helen, E-mail: helen.mango@castleton.edu [Department of Natural Sciences, Castleton State College, 233 South Street, Castleton, VT 05735 (United States); Ryan, Peter, E-mail: pryan@middlebury.edu [Department of Geology, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05753 (United States)

    2015-02-01

    Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ{sup 34}S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in {sup 34}S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ{sup 34}S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ{sup 34}S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ{sup 34}S = – 5.2 to 63‰ with higher {sup 34}S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ{sup 34}S.

  4. Health burden of skin lesions at low arsenic exposure through groundwater in Pakistan. Is river the source?

    Energy Technology Data Exchange (ETDEWEB)

    Fatmi, Zafar, E-mail: zafar.fatmi@aku.edu [Department of Community Health Sciences, Aga Khan University, Stadium Road, P.O. Box 3500, Karachi (Pakistan); Azam, Iqbal; Ahmed, Faiza; Kazi, Ambreen; Gill, Albert Bruce; Kadir, Muhmmad Masood; Ahmed, Mubashir; Ara, Naseem; Janjua, Naveed Zafar [Department of Community Health Sciences, Aga Khan University, Stadium Road, P.O. Box 3500, Karachi (Pakistan)

    2009-07-15

    A significant proportion of groundwater in south Asia is contaminated with arsenic. Pakistan has low levels of arsenic in groundwater compared with China, Bangladesh and India. A representative multi-stage cluster survey conducted among 3874 persons {>=}15 years of age to determine the prevalence of arsenic skin lesions, its relation with arsenic levels and cumulative arsenic dose in drinking water in a rural district (population: 1.82 million) in Pakistan. Spot-urine arsenic levels were compared among individuals with and without arsenic skin lesions. In addition, the relation of age, body mass index, smoking status with arsenic skin lesions was determined. The geographical distribution of the skin lesions and arsenic-contaminated wells in the district were ascertained using global positioning system. The total arsenic, inorganic and organic forms, in water and spot-urine samples were determined by atomic absorption spectrophotometry. The prevalence of skin lesions of arsenic was estimated for complex survey design, using surveyfreq and surveylogistic options of SAS 9.1 software.The prevalence of definitive cases i.e. hyperkeratosis of both palms and soles, was 3.4 per 1000 and suspected cases i.e. any sign of arsenic skin lesions (melanosis and/or keratosis), were 13.0 per 1000 among {>=}15-year-old persons in the district. Cumulative arsenic exposure (dose) was calculated from levels of arsenic in water and duration of use of current drinking water source. Prevalence of skin lesions increases with cumulative arsenic exposure (dose) in drinking water and arsenic levels in urine. Skin lesions were 2.5-fold among individuals with BMI <18.5 kg/m{sup 2}. Geographically, more arsenic-contaminated wells and skin lesions were alongside Indus River, suggests a strong link between arsenic contamination of groundwater with proximity to river.This is the first reported epidemiological and clinical evidence of arsenic skin lesions due to groundwater in Pakistan. Further

  5. On the arsenic source mobilisation and its natural enrichment in the sediments of a high mountain cirque in the Pyrenees.

    Science.gov (United States)

    Zaharescu, Dragos George; Hooda, Peter S; Fernandez, Javier; Soler, Antonio Palanca; Burghelea, Carmen Ionela

    2009-11-01

    Recently arsenic contamination and its environmental and human health problems have been raising concerns worldwide. The occurrence of natural high levels of arsenic contamination has generally been reported for low altitude environments. Here we report a study conducted to assess the extent of arsenic mobilisation/transportation from previously identified arsenic source areas in a high altitude cirque of the Pyrenees as well as the potential contribution of As by snow. The concentration of arsenic in sediments of several tributaries was enriched up to about ten folds due to mobilisation of arsenic from the source areas within the catchment. The highest arsenic enrichments were found in an area dominated by quartzite and slate formation in the southern side of the basin, and it generally diminished towards the major lake downstream, possible due to mixing with sediments from non-source areas. At these sites arsenic exceeded the hazard quotient (HQ) limits for the protection of aquatic life. The potential hazard of the As-enriched sediments may be further enhanced outside the catchment as samples collected downstream the cirque have also shown arsenic concentration exceeding HQ unity. The arsenic concentrations in the water collected at a number of sites exceeded its guide value for the protection of aquatic life. The potential As contribution by snow in the area was low and was largely of lithospheric origin. The PCA analysis showed strong association of arsenic in sediments with the sediment mineralogical composition (Fe2O3, TiO2 and Mn). Arsenic in water was positively correlated with its concentration in the sediments and could potentially increase if the environmental/climate conditions change.

  6. Sources and circulation of water and arsenic in the Giant Mine, Yellowknife, NWT, Canada.

    Science.gov (United States)

    Clark, Ian D; Raven, Kenneth G

    2004-06-01

    Recovery of gold from arsenopyrite-hosted ore in the Giant Mine camp, Yellowknife, NWT, Canada, has left a legacy of arsenic contamination that poses challenges for mine closure planning. Seepage from underground chambers storing some 237,000 tonnes of arsenic trioxide dust, has As concentrations exceeding 4000 ppm. Other potential sources and sinks of As also exist. Sources and movement of water and arsenic are traced using the isotopes of water and sulphate. Mine waters (16 ppm As; AsV/AsIII approximately 150) are a mixture of two principal water sources--locally recharged, low As groundwaters (0.5 ppm As) and Great Slave Lake (GSL; 0.004 ppm As) water, formerly used in ore processing and discharged to the northwest tailings impoundment (NWTP). Mass balance with delta18O shows that recirculation of NWTP water to the underground through faults and unsealed drillholes contributes about 60% of the mine water. Sulphate serves to trace direct infiltration to the As2O3 chambers. Sulphate in local, low As groundwaters (0.3-0.6 ppm As; delta34SSO4 approximately 4% and delta18OSO4 approximately -10%) originates from low-temperature aqueous oxidation of sulphide-rich waste rock. The high As waters gain a component of 18O-enriched sulphate derived from roaster gases (delta18OSO4) = + 3.5%), consistent with their arsenic source from the As2O3 chambers. High arsenic in NWTP water (approximately 8 ppm As; delta18OSO4 = -2%) derived from mine water, is attenuated to close to 1 ppm during infiltration back to the underground, probably by oxidation and sorption by ferrihydrite.

  7. Discrimination between diffuse and point sources of arsenic at Zimapán, Hidalgo state, Mexico.

    Science.gov (United States)

    Sracek, Ondra; Armienta, María Aurora; Rodríguez, Ramiro; Villaseñor, Guadalupe

    2010-01-01

    There are two principal sources of arsenic in Zimapán. Point sources are linked to mining and smelting activities and especially to mine tailings. Diffuse sources are not well defined and are linked to regional flow systems in carbonate rocks. Both sources are caused by the oxidation of arsenic-rich sulfidic mineralization. Point sources are characterized by Ca-SO(4)-HCO(3) ground water type and relatively enriched values of deltaD, delta(18)O, and delta(34)S(SO(4)). Diffuse sources are characterized by Ca-Na-HCO(3) type of ground water and more depleted values of deltaD, delta(18)O, and delta(34)S(SO(4)). Values of deltaD and delta(18)O indicate similar altitude of recharge for both arsenic sources and stronger impact of evaporation for point sources in mine tailings. There are also different values of delta(34)S(SO(4)) for both sources, presumably due to different types of mineralization or isotopic zonality in deposits. In Principal Component Analysis (PCA), the principal component 1 (PC1), which describes the impact of sulfide oxidation and neutralization by the dissolution of carbonates, has higher values in samples from point sources. In spite of similar concentrations of As in ground water affected by diffuse sources and point sources (mean values 0.21 mg L(-1) and 0.31 mg L(-1), respectively, in the years from 2003 to 2008), the diffuse sources have more impact on the health of population in Zimapán. This is caused by the extraction of ground water from wells tapping regional flow system. In contrast, wells located in the proximity of mine tailings are not generally used for water supply.

  8. Arsenic contamination of the environment-food chain: a survey on wheat as a test plant to investigate phytoavailable arsenic in Italian agricultural soils and as a source of inorganic arsenic in the diet.

    Science.gov (United States)

    Cubadda, Francesco; Ciardullo, Silvia; D'Amato, Marilena; Raggi, Andrea; Aureli, Federica; Carcea, Marina

    2010-09-22

    Seven hundred and twenty-six samples of wheat grains from the majority of Italian agricultural areas were pooled into 141 composite samples, homogeneous with respect to geographical origin and wheat variety. The average arsenic concentration of the pooled samples was 9 ng g(-1), with a range of 2-55 ng g(-1) (dry weight basis). The spread of arsenic concentrations (coefficient of variation of 91%) was related to spatial variability associated with geochemical and environmental factors. Temporal variability was investigated by a 3-year longitudinal study on 7 wheat cultivars grown in 22 areas of central and northern Italy. Average year-to-year variation in arsenic levels was low, and the average of the coefficients of variation was 23%. These results show that mapping of phytoavailable arsenic in agricultural soils can be done by measuring arsenic concentration in representative samples of wheat grains. Arsenic speciation in the grain showed that As(III) and As(V) were the major As compounds, highlighting the importance of wheat as a source of inorganic arsenic in the diet.

  9. Arsenic in hydrological processes-Sources, speciation, bioavailability and management

    Science.gov (United States)

    Bhattacharya, Prosun; Naidu, Ravi; Polya, David A.; Mukherjee, Abhijit; Bundschuh, Jochen; Charlet, Laurent

    2014-10-01

    Arsenic (As) is both a geogenic and anthropogenic contaminant, which poses a significant threat to human life, health and social well-being. In a number of areas worldwide, including countries in Asia, North and Latin America, parts of Europe and Africa, exposure to As in concentrations above the World Health Organization provisional guide value (WHO, 2008, 2011) through consumption of As-enriched groundwater is having adverse impacts on human health (Bhattacharya et al., 1997, 2002a, 2007; Charlet et al., 2007; Smith et al., 2000; Smedley and Kinniburgh, 2002; Welch and Stollenwerk, 2003; Kapaj et al., 2006; Nriagu et al., 2007; Naidu et al., 2006a; Naidu and Bhattacharya, 2009; Polya and Charlet, 2009; Ravenscroft et al. 2009; Mukherjee et al., 2008, 2011; Bundschuh et al., 2010, 2013). The situation is particularly serious in south and southeast Asia, where a major environmental health disaster is occurring which places an estimated 90 million people at risk of cancer and other As-related diseases.

  10. Long-term exposure to arsenic affects head kidney and impairs humoral immune responses of Clarias batrachus

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debabrata [Immunobiology Laboratory, School of Life Sciences, Visva-Bharati University, Santiniketan 731235 (India); Datta, Soma [Immunobiology Laboratory, School of Life Sciences, Visva-Bharati University, Santiniketan 731235 (India); Bhattacharya, Shelley [Environmental Toxicology Laboratory, School of Life Sciences, Visva-Bharati University, Santiniketan 731235 (India); Mazumder, Shibnath [Immunobiology Laboratory, School of Life Sciences, Visva-Bharati University, Santiniketan 731235 (India)]. E-mail: shibnath1@yahoo.co.in

    2007-02-15

    The present study was aimed at determining the effects of long-term arsenic exposure on the head kidney (HK) and ensuing humoral immune responses in Clarias batrachus L. Long-term exposure (150 days) to non-lethal concentrations of arsenic (42.42 {mu}M) resulted in significant time-dependent alterations in HK cell number eventually affecting the HK somatic index. Prolonged exposure to arsenic also suppressed HK-B cell proliferation and led to significant reduction in serum immunoglobulin levels and antigen-specific serum bacterial agglutinin titers. A decline in the number of antigen-specific plaque-forming cells with duration of arsenic exposure was noted in the HK. Enzyme linked immunosorbent assays further revealed that arsenic exposure inhibited the release of 'IL-4 like factors' from HK-T cells. Histological studies documented time-dependent changes in the structure and cellular composition of HK characterized by extensive lymphocytopenia, decrease in melano-macrophage population and hemosiderin accumulation. From exposure-challenge studies with Aeromonas hydrophila it was evident that pathogens could efficiently disseminate and colonize distant host tissues in the exposed fish. Moreover, the ability to decrease the pathogen load was also significantly reduced in the arsenic-exposed fish. Thus long-term exposure to non-lethal concentrations of arsenic affects HK and interferes with the humoral immune system of C. batrachus rendering them immunocompromised and susceptible to pathogenic challenge.

  11. HTGR Mechanistic Source Terms White Paper

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Moe

    2010-07-01

    The primary purposes of this white paper are: (1) to describe the proposed approach for developing event specific mechanistic source terms for HTGR design and licensing, (2) to describe the technology development programs required to validate the design methods used to predict these mechanistic source terms and (3) to obtain agreement from the NRC that, subject to appropriate validation through the technology development program, the approach for developing event specific mechanistic source terms is acceptable

  12. SOURCE TERMS FOR AVERAGE DOE SNF CANISTERS

    Energy Technology Data Exchange (ETDEWEB)

    K. L. Goluoglu

    2000-06-09

    The objective of this calculation is to generate source terms for each type of Department of Energy (DOE) spent nuclear fuel (SNF) canister that may be disposed of at the potential repository at Yucca Mountain. The scope of this calculation is limited to generating source terms for average DOE SNF canisters, and is not intended to be used for subsequent calculations requiring bounding source terms. This calculation is to be used in future Performance Assessment calculations, or other shielding or thermal calculations requiring average source terms.

  13. Validation of In-Situ Iron-Manganese Oxide Coated Stream Pebbles as Sensors for Arsenic Source Monitoring

    Science.gov (United States)

    Blake, J.; Peters, S. C.; Casteel, A.

    2013-12-01

    Locating nonpoint source contaminant fluxes can be challenging due to the inherent heterogeneity of source and of the subsurface. Contaminants such as arsenic are a concern for drinking water quality and ecosystem health. Arsenic contamination can be the result of several natural and anthropogenic sources, and therefore it can be difficult to trace and identify major areas of arsenic in natural systems. Identifying a useful source indicator for arsenic is a crucial step for environmental remediation efforts. Previous studies have found iron-manganese oxide coated streambed pebbles as useful source indicators due to their high attraction for heavy metals in water. In this study, pebbles, surface water at baseflow and nearby rocks were sampled from the Pennypack Creek and its tributaries, in southwestern Pennsylvania, to test the ability of coated streambed pebbles as environmental source indicators for arsenic. Quartz pebbles, 5-7 cm in diameter, were sampled to minimize elemental contamination from rock chemistry. In addition, quartz provides an excellent substrate for iron and manganese coatings to form. These coatings were leached from pebbles using 4M nitric acid with 0.1% concentrated hydrochloric acid. Following sample processing, analyses were performed using an ICP-MS and the resulting data were spatially organized using ArcGIS software. Arsenic, iron and manganese concentrations in the leachate are normalized to pebble surface area and each location is reported as a ratio of arsenic to iron and manganese. Results suggest that iron-manganese coated stream pebbles are useful indicators of arsenic location within a watershed.

  14. Study of Arsenic Presence in Drinking Water Sources: A Case Study

    OpenAIRE

    Kamali, Z.; Borghei, M.; AM Hassani; H Taghipour; M Mosaferi; A Ghadirzadeh

    2008-01-01

    Background and Objectives: Conducted studies about arsenic have shown that consumption of water contaminated with arsenic can causes different adverse health effects in consumers. World Health Organization (WHO) has enacted 10µg/L arsenic in drinking water as a guideline value. Regarding some reports about arsenic presence in a village of Hashtrood county and related health effects and also considering this fact that determination of arsenic as a poisoning chemical is not included in ro...

  15. Comparative evaluation of short-term toxicity of inorganic arsenic compounds on Artemia salina.

    Science.gov (United States)

    GuŢu, Claudia Maria; Olaru, Octavian Tudorel; Purdel, Nicoleta Carmen; Ilie, Mihaela; NeamŢu, Marius Cristian; Dănciulescu Miulescu, Rucsandra; Avramescu, Elena Taina; Margină, Denisa Marilena

    2015-01-01

    The study aimed to assess the short-term effects exerted by two inorganic arsenic species (arsenite and arsenate) on Artemia salina after 24, 48 and 72 h. The dose-lethality curves obtained indicate that the lethality induced by arsenite was higher than by arsenate. The lowest observed effect concentration for arsenite (0.5 μg/mL) is similar with the no observed effect concentration for arsenate, thus indicating that the toxicity of arsenite is higher compared with arsenate. Also, the lethal concentration 50 values confirm that arsenite induced about 1.24-fold higher toxicity than arsenate at 24 h and about three-fold higher toxicity at 48 h and 72 h of exposure. Both LC50 (lethal concentration 50) values are indicating negligible effects exhibited by arsenic at this trophic level after short-term exposure. The predicted no effect concentration in the surface aquatic compartment corresponds to 10.38 μg/L, similar to the limit imposed by Directive 98/83/EC.

  16. Arsenic in the soils of Zimapán, Mexico.

    Science.gov (United States)

    Ongley, Lois K; Sherman, Leslie; Armienta, Aurora; Concilio, Amy; Salinas, Carrie Ferguson

    2007-02-01

    Arsenic concentrations of 73 soil samples collected in the semi-arid Zimapán Valley range from 4 to 14 700 mg As kg(-1). Soil arsenic concentrations decrease with distance from mines and tailings and slag heaps and exceed 400 mg kg(-1) only within 500 m of these arsenic sources. Soil arsenic concentrations correlate positively with Cu, Pb, and Zn concentrations, suggesting a strong association with ore minerals known to exist in the region. Some As was associated with Fe and Mn oxyhydroxides, this association is less for contaminated than for uncontaminated samples. Very little As was found in the mobile water-soluble or exchangeable fractions. The soils are not arsenic contaminated at depths greater than 100 cm below the surface. Although much of the arsenic in the soils is associated with relatively immobile solid phases, this represents a long-term source of arsenic to the environment.

  17. Mineral sources and transport pathways for arsenic release in a coastal watershed, USA

    Science.gov (United States)

    Foley, Nora K.; Ayuso, Robert A.

    2008-01-01

    Metasedimentary bedrock of coastal Maine contains a diverse suite of As-bearing minerals that act as significant sources of elements found in ground and surface waters in the region. Arsenic sources in the Penobscot Formation include, in order of decreasing As content by weight: löllingite and realgar (c.70%), arsenopyrite, cobaltite, glaucodot, and gersdorffite (in the range of 34–45%), arsenian pyrite ( glaucodot, arsenopyrite-cobaltian > arsenopyrite, cobaltite, gersdorffite, fine-grained pyrite, Ni-pyrite > coarse-grained pyrite. Reactions illustrate that oxidation of Fe-As disulphide group and As-sulphide minerals is the primary release process for As. Liberation of As by carbonation of realgar and orpiment in contact with high-pH groundwaters may contribute locally to elevated contents of As in groundwater, especially where As is decoupled from Fe. Released metals are sequestered in secondary minerals by sorption or by incorporation in crystal structures. Secondary minerals acting as intermediate As reservoirs include claudetite (c.75%), orpiment (61%), scorodite (c. 45%), secondary arsenopyrite (c. 46%), goethite (<4490 ppm), natrojarosite (<42 ppm), rosenite, melanterite, ferrihydrite, and Mn-hydroxide coatings. Some soils also contain Fe-Co-Ni-arsenate, Ca-arsenate, and carbonate minerals. Reductive dissolution of Fe-oxide minerals may govern the ultimate release of iron and arsenic – especially As(V) – to groundwater; however, dissolution of claudetite (arsenic trioxide) may directly contribute As(III). Processes thought to explain the release of As from minerals in bedrock include oxidation of arsenian pyrite or arsenopyrite, or carbonation of As-sulphides, and most models based on these generally rely on discrete minerals or on a fairly limited series of minerals. In contrast, in the Penobscot Formation and other metasedimentary rocks of coastal Maine, oxidation of As-bearing Fe-cobalt-nickel-sulphide minerals, dissolution (by reduction) of

  18. Arsenic contamination of groundwater: a review of sources, prevalence, health risks, and strategies for mitigation.

    Science.gov (United States)

    Shankar, Shiv; Shanker, Uma; Shikha

    2014-01-01

    Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial) for mitigation of the problem of As contamination of groundwater.

  19. Arsenic Contamination of Groundwater: A Review of Sources, Prevalence, Health Risks, and Strategies for Mitigation

    Directory of Open Access Journals (Sweden)

    Shiv Shankar

    2014-01-01

    Full Text Available Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial for mitigation of the problem of As contamination of groundwater.

  20. Arsenic Contamination of Groundwater: A Review of Sources, Prevalence, Health Risks, and Strategies for Mitigation

    Science.gov (United States)

    Shikha

    2014-01-01

    Arsenic contamination of groundwater in different parts of the world is an outcome of natural and/or anthropogenic sources, leading to adverse effects on human health and ecosystem. Millions of people from different countries are heavily dependent on groundwater containing elevated level of As for drinking purposes. As contamination of groundwater, poses a serious risk to human health. Excessive and prolonged exposure of inorganic As with drinking water is causing arsenicosis, a deteriorating and disabling disease characterized by skin lesions and pigmentation of the skin, patches on palm of the hands and soles of the feet. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of As and global overview of groundwater As contamination. The paper also critically reviews the As led human health risks, its uptake, metabolism, and toxicity mechanisms. The paper provides an overview of the state-of-the-art knowledge on the alternative As free drinking water and various technologies (oxidation, coagulation flocculation, adsorption, and microbial) for mitigation of the problem of As contamination of groundwater. PMID:25374935

  1. Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

    OpenAIRE

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

    2003-01-01

    Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hai...

  2. A short-term study to evaluate the uptake and accumulation of arsenic in Asian willow (Salix sp.) from arsenic-contaminated water.

    Science.gov (United States)

    Chen, Guangcai; Zou, Xiaoli; Zhou, Yuan; Zhang, Jianfeng; Owens, Gary

    2014-03-01

    Five Asian willow species (Salix jiangsuensis J172, Salix matsudana, Salix integra Yizhibi, Salix integra Weishanhu, and Salix mongolica) were evaluated for their potential for phytofiltration of arsenic (As) from synthetically contaminated waters. Arsenic accumulation, tolerance, uptake influx, and phytofiltration ability of the five willow species were examined under hydroponic conditions in a glasshouse. Short-term exposure (2 weeks) to solutions containing 80 μmol L(-1) arsenate (As(V)), resulted in significant accumulation of As in all willow species. Arsenic concentration in plant roots ranged from 322 mg kg(-1) dry weight (DW) for S. matsudana to 604 mg kg(-1) (DW) for S. integra Yizhibi. S. integra Yizhibi decreased As(V) concentration in water from 3.87 to 1.89 μmol L(-1) (290 to 142 μg L(-1)) over 168 h, which is 50 % of the total As(V) in the solution. The results suggested that even though Asian willow was not a traditional aquatic species, it still had significant potential for phytofiltration of As from contaminated waters. Of the five willow species studied, S. integra Yizhibi had the greatest capacity to remove As from As-contaminated waters. Thus, Asian willow has significant potential for the phytofiltration of As and may also be suitable for practical phytoremediation of As in highly water-logged areas.

  3. Source apportionment of arsenic in atmospheric dust fall out in an urban residential area, Raipur, Central India

    Directory of Open Access Journals (Sweden)

    G. Balakrishna

    2011-06-01

    Full Text Available The components and quantities of atmospheric dust fallout have been reported to be the pollution indicator of large urban areas. The multiplicity and complexity of sources of atmospheric dusts in urban regions has put forward the need of source apportionment of these sources indicating their contribution to specific environmental receptor. The study presented here is focused on investigation of source contribution estimates of Arsenic in urban dust fallout in an urban-industrial area, Raipur, India. Source-receptor based representative sampling plan using longitudinal study design has been adopted. Six sampling sites have been identified on the basis of land use for development plan of anthropogenic activities and factors related to the transportation and dispersion pattern of atmospheric dusts. Source apportionment has been done using Chemical Mass Balance (CMB 8. Good fit parameters and relative source contribution has been analyzed and documented. Dominance of coal fired industries sources on arsenic levels measured at selected ambient residential receptors compared to line sources has been observed. Road-traffic has shown highest contribution of dust at indoor houses and out door-street automobile exhaust has shows highest contribution for arsenic. The results of CMB output and regression data of source-receptor dust matrices have shown comparable pattern.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Yongfang Li

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  7. Assessing the microbial community and functional genes in a vertical soil profile with long-term arsenic contamination.

    Directory of Open Access Journals (Sweden)

    Jinbo Xiong

    Full Text Available Arsenic (As contamination in soil and groundwater has become a serious problem to public health. To examine how microbial communities and functional genes respond to long-term arsenic contamination in vertical soil profile, soil samples were collected from the surface to the depth of 4 m (with an interval of 1 m after 16-year arsenic downward infiltration. Integrating BioLog and functional gene microarray (GeoChip 3.0 technologies, we showed that microbial metabolic potential and diversity substantially decreased, and community structure was markedly distinct along the depth. Variations in microbial community functional genes, including genes responsible for As resistance, carbon and nitrogen cycling, phosphorus utilization and cytochrome c oxidases were detected. In particular, changes in community structures and activities were correlated with the biogeochemical features along the vertical soil profile when using the rbcL and nifH genes as biomarkers, evident for a gradual transition from aerobic to anaerobic lifestyles. The C/N showed marginally significant correlations with arsenic resistance (p = 0.069 and carbon cycling genes (p = 0.073, and significant correlation with nitrogen fixation genes (p = 0.024. The combination of C/N, NO(3 (- and P showed the highest correlation (r = 0.779, p = 0.062 with the microbial community structure. Contradict to our hypotheses, a long-term arsenic downward infiltration was not the primary factor, while the spatial isolation and nutrient availability were the key forces in shaping the community structure. This study provides new insights about the heterogeneity of microbial community metabolic potential and future biodiversity preservation for arsenic bioremediation management.

  8. Assessing the microbial community and functional genes in a vertical soil profile with long-term arsenic contamination.

    Science.gov (United States)

    Xiong, Jinbo; He, Zhili; Van Nostrand, Joy D; Luo, Guosheng; Tu, Shuxin; Zhou, Jizhong; Wang, Gejiao

    2012-01-01

    Arsenic (As) contamination in soil and groundwater has become a serious problem to public health. To examine how microbial communities and functional genes respond to long-term arsenic contamination in vertical soil profile, soil samples were collected from the surface to the depth of 4 m (with an interval of 1 m) after 16-year arsenic downward infiltration. Integrating BioLog and functional gene microarray (GeoChip 3.0) technologies, we showed that microbial metabolic potential and diversity substantially decreased, and community structure was markedly distinct along the depth. Variations in microbial community functional genes, including genes responsible for As resistance, carbon and nitrogen cycling, phosphorus utilization and cytochrome c oxidases were detected. In particular, changes in community structures and activities were correlated with the biogeochemical features along the vertical soil profile when using the rbcL and nifH genes as biomarkers, evident for a gradual transition from aerobic to anaerobic lifestyles. The C/N showed marginally significant correlations with arsenic resistance (p = 0.069) and carbon cycling genes (p = 0.073), and significant correlation with nitrogen fixation genes (p = 0.024). The combination of C/N, NO(3) (-) and P showed the highest correlation (r = 0.779, p = 0.062) with the microbial community structure. Contradict to our hypotheses, a long-term arsenic downward infiltration was not the primary factor, while the spatial isolation and nutrient availability were the key forces in shaping the community structure. This study provides new insights about the heterogeneity of microbial community metabolic potential and future biodiversity preservation for arsenic bioremediation management.

  9. Arsenic Content of the Drinking Water Source, for the Guadiana Valley, Mexico; Contenido de arsenico en el agua potable de Valle del Guadiana, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Alarcon Herrera, Maria Teresa [Centro de Investigacion en Materiales Avanzados (Mexico); Flores Montenegro, Isela [Sistema Desentralizado de agua Potable y alcantarillado Durango (Mexico); Romero Navar, Pedro [Comision Nacional del Agua (Mexico); Martin Dominguez, Ignacio [Centro de Investigacion en Materiales Avanzados (Mexico); Trejo Vazquez, Rodolfo [Instituto Tecnologico de Aguascalientes (Mexico)

    2001-12-01

    In recent years, high levels of arsenic concentration have been detected in some drinking water sources of the Guadiana Valley (Durango and surrounding towns) in Mexico. These levels are above the limits recommended bye the world Health Organization (WHO) and the maximum levels allowed by the Mexican standards. due to the well.known toxicity of this element, this study set as its objective to determine in quantitative terms the arsenic content of the drinking water sources for the Guadiana Valley, as the first step in the way to solve environment problems, It was found that 59% of the sources in the south, northeast and Northwest zones of Durango exceed in 40% the maximum level established by Mexican standards for arsenic content. In the Guadiana towns, 48% of the sources surpass such levels even in 46%. If the maximum levels suggested bye the WHO are taken as the reference, then virtually all sources exceed such level. [Spanish] En los ultimos anos, en la region del valle de Gadiana (ciudad de Durango y poblados cercanos) se han detectado niveles de concentracion de arsenico (As) en algunos pozos de abastecimiento de agua potable que superan los limites recomendados por la Organizacion Mundial de la Salud(OMS) y el limite maximo permisible establecido por la legislacion mexicana. Dada la conocida toxicidad de dicho elemento, en el presente estudio se propuso determinar cuantitativamente el contenido de arsenico en los pozos de abastecimiento de agua potable del valle del Guadiana, como un primer paso hacia la solucion de la problematica ambiental. Se encontro que en la zona sureste, noroeste y noreste de la ciudad, en 59% de los pozos se excede hasta en 40% la concentracion de arsenico establecida como limite maximo por la legislacion mexicana. En las poblaciones del valle del Guadiana, 48% de los pozos superan los limites mencionados hasta en un 136%. Si se toma como referencia el limite maximo establecido por la OMS, practicamente todos los pozos exceden el

  10. BWR Source Term Generation and Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    J.C. Ryman

    2003-07-31

    This calculation is a revision of a previous calculation (Ref. 7.5) that bears the same title and has the document identifier BBAC00000-01717-0210-00006 REV 01. The purpose of this revision is to remove TBV (to-be-verified) -41 10 associated with the output files of the previous version (Ref. 7.30). The purpose of this and the previous calculation is to generate source terms for a representative boiling water reactor (BWR) spent nuclear fuel (SNF) assembly for the first one million years after the SNF is discharged from the reactors. This calculation includes an examination of several ways to represent BWR assemblies and operating conditions in SAS2H in order to quantify the effects these representations may have on source terms. These source terms provide information characterizing the neutron and gamma spectra in particles per second, the decay heat in watts, and radionuclide inventories in curies. Source terms are generated for a range of burnups and enrichments (see Table 2) that are representative of the waste stream and stainless steel (SS) clad assemblies. During this revision, it was determined that the burnups used for the computer runs of the previous revision were actually about 1.7% less than the stated, or nominal, burnups. See Section 6.6 for a discussion of how to account for this effect before using any source terms from this calculation. The source term due to the activation of corrosion products deposited on the surfaces of the assembly from the coolant is also calculated. The results of this calculation support many areas of the Monitored Geologic Repository (MGR), which include thermal evaluation, radiation dose determination, radiological safety analyses, surface and subsurface facility designs, and total system performance assessment. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Disposal Container (Ref. 7.27, page 7). Therefore, this calculation is subject to the requirements of the

  11. Phosphate fertilizer is a main source of arsenic in areas affected with chronic kidney disease of unknown etiology in Sri Lanka.

    Science.gov (United States)

    Jayasumana, Channa; Fonseka, Saranga; Fernando, Ashvin; Jayalath, Kumudika; Amarasinghe, Mala; Siribaddana, Sisira; Gunatilake, Sarath; Paranagama, Priyani

    2015-01-01

    Chronic Kidney Disease of unknown etiology (CKDu) has escalated into an epidemic in North Central Province (NCP) and adjacent farming areas in the dry zone of Sri Lanka. Studies have shown that this special type of CKD is a toxic nephropathy and arsenic may play a causative role along with a number of other heavy metals. We investigated the hypothesis that chemical fertilizers and pesticide could be a source of arsenic. 226 samples of Fertilizers and 273 samples of pesticides were collected and analyzed using atomic absorption spectrometry and inductively coupled plasma mass spectrometry for arsenic and other heavy metals in two university laboratories. Almost all the agrochemicals available to the farmers in the study area are contaminated with arsenic. The highest amount was in triple super phosphate (TSP) with a mean value of 31 mg/kg. Also TSP is a rich source of other nephrotoxic metals including Cr, Co, Ni, Pb and V. Annually more than 0.1 million tons of TSP is imported to Sri Lanka containing approximately 2100 kg of arsenic. The next highest concentration was seen in the rock phosphate obtained from an open pit mine in NCP (8.56 mg/kg). Organic fertilizer contained very low amounts of arsenic. Arsenic contamination in pesticides varied from 0.18 mg/kg to 2.53 mg/kg although arsenic containing pesticides are banned in Sri Lanka. Glyphosate the most widely used pesticide in Sri Lanka contains average of 1.9 mg/kg arsenic. Findings suggest that agrochemicals especially phosphate fertilizers are a major source of inorganic arsenic in CKDu endemic areas. Organic fertilizer available in Sri Lanka is comparatively very low in arsenic and hence the farmers in CKDu endemic areas in Sri Lanka should be encouraged to minimize the use of imported chemical fertilizer and use organic fertilizers instead.

  12. Dietary sources of methylated arsenic species in urine of the United States population, NHANES 2003-2010.

    Directory of Open Access Journals (Sweden)

    B Rey deCastro

    Full Text Available BACKGROUND: Arsenic is an ubiquitous element linked to carcinogenicity, neurotoxicity, as well as adverse respiratory, gastrointestinal, hepatic, and dermal health effects. OBJECTIVE: Identify dietary sources of speciated arsenic: monomethylarsonic acid (MMA, and dimethylarsinic acid (DMA. METHODS: Age-stratified, sample-weighted regression of NHANES (National Health and Nutrition Examination Survey 2003-2010 data (∼8,300 participants ≥6 years old characterized the association between urinary arsenic species and the additional mass consumed of USDA-standardized food groups (24-hour dietary recall data, controlling for potential confounders. RESULTS: For all arsenic species, the rank-order of age strata for median urinary molar concentration was children 6-11 years > adults 20-84 years > adolescents 12-19 years, and for all age strata, the rank-order was DMA > MMA. Median urinary molar concentrations of methylated arsenic species ranged from 0.56 to 3.52 µmol/mol creatinine. Statistically significant increases in urinary arsenic species were associated with increased consumption of: fish (DMA; fruits (DMA, MMA; grain products (DMA, MMA; legumes, nuts, seeds (DMA; meat, poultry (DMA; rice (DMA, MMA; rice cakes/crackers (DMA, MMA; and sugars, sweets, beverages (MMA. And, for adults, rice beverage/milk (DMA, MMA. In addition, based on US (United States median and 90th percentile consumption rates of each food group, exposure from the following food groups was highlighted: fish; fruits; grain products; legumes, nuts, seeds; meat, poultry; and sugars, sweets, beverages. CONCLUSIONS: In a nationally representative sample of the US civilian, noninstitutionalized population, fish (adults, rice (children, and rice cakes/crackers (adolescents had the largest associations with urinary DMA. For MMA, rice beverage/milk (adults and rice cakes/crackers (children, adolescents had the largest associations.

  13. An insight of environmental contamination of arsenic on animal health

    Directory of Open Access Journals (Sweden)

    Paramita Mandal

    2017-03-01

    Full Text Available The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. Exposure to arsenic is mainly via intake of food and drinking water, food being the most important source in most populations. Although adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues and is even increasing in some areas. Long-term exposure to arsenic in drinking-water is mainly related to increased risks of skin cancer, but also some other cancers, as well as other skin lesions such as hyperkeratosis and pigmentation changes. Therefore, measures should be taken to reduce arsenic exposure in the general population in order to minimize the risk of adverse health effects. Animal are being exposed to arsenic through contaminated drinking water, feedstuff, grasses, vegetables and different leaves. Arsenic has been the most common causes of inorganic chemical poisoning in farm animals. Although, sub-chronic and chronic exposure of arsenic do not generally reveal external signs or symptoms in farm animals but arsenic (or metabolites concentrations in blood, hair, hoofs and urine are remained high in animals of arsenic contaminated zones. So it is assumed that concentration of arsenic in blood, urine, hair or milk have been used as biomarkers of arsenic exposure in field animals.

  14. Holocene estuarine sediments as a source of arsenic in Pleistocene groundwater in suburbs of Hanoi, Vietnam

    Science.gov (United States)

    Kuroda, Keisuke; Hayashi, Takeshi; Funabiki, Ayako; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Takizawa, Satoshi

    2017-06-01

    Groundwater pollution by arsenic is a major health threat in suburban areas of Hanoi, Vietnam. The present study evaluates the effect of the sedimentary environments of the Pleistocene and Holocene deposits, and the recharge systems, on the groundwater arsenic pollution in Hanoi suburbs distant from the Red River. At two study sites (Linh Dam and Tai Mo communes), undisturbed soil cores identified a Pleistocene confined aquifer (PCA) and Holocene unconfined aquifer (HUA) as major aquifers, and Holocene estuarine and deltaic sediments as an aquitard layer between the two aquifers. The Holocene estuarine sediments (approximately 25-40 m depth, 9.6-4.8 cal ka BP) contained notably high concentrations of arsenic and organic matter, both likely to have been accumulated by mangroves during the Holocene sea-level highstand. The pore waters in these particular sediments exhibited elevated levels of arsenic and dissolved organic carbon. Arsenic in groundwater was higher in the PCA (25-94 μg/L) than in the HUA (5.2-42 μg/L), in both the monitoring wells and neighboring household tubewells. Elevated arsenic concentration in the PCA groundwater was likely due to vertical infiltration through the arsenic-rich and organic-matter-rich overlying Holocene estuarine sediments, caused by massive groundwater abstraction from the PCA. Countermeasures to prevent arsenic pollution of the PCA groundwater may include seeking alternative water resources, reducing water consumption, and/or appropriate choice of aquifers for groundwater supply.

  15. Holocene estuarine sediments as a source of arsenic in Pleistocene groundwater in suburbs of Hanoi, Vietnam

    Science.gov (United States)

    Kuroda, Keisuke; Hayashi, Takeshi; Funabiki, Ayako; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Takizawa, Satoshi

    2017-01-01

    Groundwater pollution by arsenic is a major health threat in suburban areas of Hanoi, Vietnam. The present study evaluates the effect of the sedimentary environments of the Pleistocene and Holocene deposits, and the recharge systems, on the groundwater arsenic pollution in Hanoi suburbs distant from the Red River. At two study sites (Linh Dam and Tai Mo communes), undisturbed soil cores identified a Pleistocene confined aquifer (PCA) and Holocene unconfined aquifer (HUA) as major aquifers, and Holocene estuarine and deltaic sediments as an aquitard layer between the two aquifers. The Holocene estuarine sediments (approximately 25-40 m depth, 9.6-4.8 cal ka uc(BP)) contained notably high concentrations of arsenic and organic matter, both likely to have been accumulated by mangroves during the Holocene sea-level highstand. The pore waters in these particular sediments exhibited elevated levels of arsenic and dissolved organic carbon. Arsenic in groundwater was higher in the PCA (25-94 μg/L) than in the HUA (5.2-42 μg/L), in both the monitoring wells and neighboring household tubewells. Elevated arsenic concentration in the PCA groundwater was likely due to vertical infiltration through the arsenic-rich and organic-matter-rich overlying Holocene estuarine sediments, caused by massive groundwater abstraction from the PCA. Countermeasures to prevent arsenic pollution of the PCA groundwater may include seeking alternative water resources, reducing water consumption, and/or appropriate choice of aquifers for groundwater supply.

  16. Health risk assessment for arsenic in water sources of cankiri province of Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Caylak, Emrah [Department of Biochemistry, School of Health, Karatekin University, Cankiri (Turkey)

    2012-07-15

    To investigate the levels of arsenic (As) in the water sources of Cankiri Province, the samples were collected from the stations of central Cankiri (n = 27) and Kursunlu town (n = 12) during 2009 and 2010. The concentrations of As were analyzed with an atomic absorption spectrophotometer, and then compared with permissible limit, 10 {mu}g/L in drinking water, by Turkish legislation and World Health Organization (WHO). The As levels were higher than this limit (mean value 10-30 {mu}g/L in 26 stations), whereas, they were found to be >30 {mu}g/L in 12 sampling points. The water sources were categorized for health risk assessment such as reservoir, tap, well, and spring, and then chronic daily intake for oral and dermal exposure to As via drinking water, hazard quotient (HQ), and hazard index were calculated by using indices. The HQ values were found to be >1 in all samples of Cankiri Province. The effects of As on human health were then evaluated using carcinogenic risk (CR). CR values for As were also estimated to be >10{sup -5} in drinking water samples of Cankiri Province and might exert potential CR for people. These assessments would point out required drinking water treatment strategy to ensure safety of consumers. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Arsenic in rice: A cause for concern

    DEFF Research Database (Denmark)

    Hojsak, Iva; Braegger, Christian; Bronsky, Jiri

    2015-01-01

    Inorganic arsenic intake is likely to affect long-term health. High concentrations are found in some rice-based foods and drinks widely used in infants and young children. In order to reduce exposure we recommend avoidance of rice drinks for infants and young children. For all rice products, strict...... regulation should be enforced regarding arsenic content. Moreover, infants and young children should consume a balanced diet including a variety of grains as carbohydrate sources. While rice protein based infant formulas are an option for infants with cows' milk protein allergy, the inorganic arsenic content...

  18. Risk of death from cardiovascular disease associated with low-level arsenic exposure among long-term smokers in a US population-based study

    Energy Technology Data Exchange (ETDEWEB)

    Farzan, Shohreh F. [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States); Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY (United States); Chen, Yu [Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY (United States); Rees, Judy R.; Zens, M. Scot [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States); Karagas, Margaret R., E-mail: margaret.r.karagas@dartmouth.edu [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States)

    2015-09-01

    High levels of arsenic exposure have been associated with increases in cardiovascular disease risk. However, studies of arsenic's effects at lower exposure levels are limited and few prospective studies exist in the United States using long-term arsenic exposure biomarkers. We conducted a prospective analysis of the association between toenail arsenic and cardiovascular disease mortality using longitudinal data collected on 3939 participants in the New Hampshire Skin Cancer Study. Using Cox proportional hazard models adjusted for potential confounders, we estimated hazard ratios and 95% confidence intervals associated with the risk of death from any cardiovascular disease, ischemic heart disease, and stroke, in relation to natural-log transformed toenail arsenic concentrations. In this US population, although we observed no overall association, arsenic exposure measured from toenail clipping samples was related to an increased risk of ischemic heart disease mortality among long-term smokers (as reported at baseline), with increased hazard ratios among individuals with ≥ 31 total smoking years (HR: 1.52, 95% CI: 1.02, 2.27), ≥ 30 pack-years (HR: 1.66, 95% CI: 1.12, 2.45), and among current smokers (HR: 1.69, 95% CI: 1.04, 2.75). These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality. - Highlights: • Arsenic (As) has been associated with increased cardiovascular disease (CVD) risk. • Little is known about CVD effects at lower levels of As exposure common in the US. • Few have investigated the joint effects of As and smoking on CVD in US adults. • We examine chronic low-level As exposure and smoking in relation to CVD mortality. • Arsenic exposure may increase ischemic heart disease mortality among smokers in US.

  19. Historical arsenic contamination of soil due to long-term phosphate fertiliser applications.

    Science.gov (United States)

    Hartley, Tom N; Macdonald, Andy J; McGrath, Steve P; Zhao, Fang-Jie

    2013-09-01

    Archived samples from the Park Grass Experiment, established in 1856, were analysed to determine the impacts of long-term phosphate fertiliser applications on arsenic concentrations in soil and herbage. In plots receiving 35 kg P ha(-1) annually (+P), topsoil As concentrations almost doubled from an initial value of ∼10 mg kg(-1) during 1888-1947 and remained stable thereafter. The phosphate fertilisers used before 1948 contained 401-1575 mg As kg(-1), compared to 1.6-20.3 mg As kg(-1) in the later samples. Herbage samples from the +P plots collected during 1888-1947 contained significantly more As than those from the -P plots, but later samples did not differ significantly. Mass-balance calculations show that the increase in soil As can be explained by the As input from P fertiliser applications before 1948. The results demonstrate that the P fertilisers used on the Park Grass Experiment before 1948 caused substantial As contamination of the soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Risk of death from cardiovascular disease associated with low-level arsenic exposure among long-term smokers in a US population-based study

    Science.gov (United States)

    Farzan, Shohreh F.; Chen, Yu; Rees, Judy R.; Zens, M. Scot; Karagas, Margaret R.

    2015-01-01

    High levels of arsenic exposure have been associated with increases in cardiovascular disease risk. However, studies of arsenic’s effects at lower exposure levels are limited and few prospective studies exist in the United States using long-term arsenic exposure biomarkers. We conducted a prospective analysis of the association between toenail arsenic and cardiovascular disease mortality using longitudinal data collected on 3939 participants in the New Hampshire Skin Cancer Study. Using Cox proportional hazard models adjusted for potential confounders, we estimated hazard ratios and 95% confidence intervals associated with the risk of death from any cardiovascular disease, ischemic heart disease, and stroke, in relation to natural-log transformed toenail arsenic concentrations. In this US population, although we observed no overall association, arsenic exposure measured from toenail clipping samples was related to an increased risk of ischemic heart disease mortality among long-term smokers (as reported at baseline), with increased hazard ratios among individuals with ≥ 31 total smoking years (HR: 1.52, 95% CI: 1.02, 2.27), ≥ 30 pack-years (HR: 1.66, 95% CI: 1.12, 2.45), and among current smokers (HR: 1.69, 95% CI: 1.04, 2.75). These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality. PMID:26048586

  1. TRIGA MARK-II source term

    Science.gov (United States)

    Usang, M. D.; Hamzah, N. S.; J. B., Abi M.; M. Z., M. Rawi; Abu, M. P.

    2014-02-01

    ORIGEN 2.2 are employed to obtain data regarding γ source term and the radio-activity of irradiated TRIGA fuel. The fuel composition are specified in grams for use as input data. Three types of fuel are irradiated in the reactor, each differs from the other in terms of the amount of Uranium compared to the total weight. Each fuel are irradiated for 365 days with 50 days time step. We obtain results on the total radioactivity of the fuel, the composition of activated materials, composition of fission products and the photon spectrum of the burned fuel. We investigate the differences of results using BWR and PWR library for ORIGEN. Finally, we compare the composition of major nuclides after 1 year irradiation of both ORIGEN library with results from WIMS. We found only minor disagreements between the yields of PWR and BWR libraries. In comparison with WIMS, the errors are a little bit more pronounced. To overcome this errors, the irradiation power used in ORIGEN could be increased a little, so that the differences in the yield of ORIGEN and WIMS could be reduced. A more permanent solution is to use a different code altogether to simulate burnup such as DRAGON and ORIGEN-S. The result of this study are essential for the design of radiation shielding from the fuel.

  2. TRIGA MARK-II source term

    Energy Technology Data Exchange (ETDEWEB)

    Usang, M. D., E-mail: mark-dennis@nuclearmalaysia.gov.my; Hamzah, N. S., E-mail: mark-dennis@nuclearmalaysia.gov.my; Abi, M. J. B., E-mail: mark-dennis@nuclearmalaysia.gov.my; Rawi, M. Z. M. Rawi, E-mail: mark-dennis@nuclearmalaysia.gov.my; Abu, M. P., E-mail: mark-dennis@nuclearmalaysia.gov.my [Bahagian Teknologi Reaktor, Agensi Nuklear Malaysia, 43000 Kajang (Malaysia)

    2014-02-12

    ORIGEN 2.2 are employed to obtain data regarding γ source term and the radio-activity of irradiated TRIGA fuel. The fuel composition are specified in grams for use as input data. Three types of fuel are irradiated in the reactor, each differs from the other in terms of the amount of Uranium compared to the total weight. Each fuel are irradiated for 365 days with 50 days time step. We obtain results on the total radioactivity of the fuel, the composition of activated materials, composition of fission products and the photon spectrum of the burned fuel. We investigate the differences of results using BWR and PWR library for ORIGEN. Finally, we compare the composition of major nuclides after 1 year irradiation of both ORIGEN library with results from WIMS. We found only minor disagreements between the yields of PWR and BWR libraries. In comparison with WIMS, the errors are a little bit more pronounced. To overcome this errors, the irradiation power used in ORIGEN could be increased a little, so that the differences in the yield of ORIGEN and WIMS could be reduced. A more permanent solution is to use a different code altogether to simulate burnup such as DRAGON and ORIGEN-S. The result of this study are essential for the design of radiation shielding from the fuel.

  3. Arsenic in New England: Mineralogical and geochemical studies of sources and enrichment pathways

    Science.gov (United States)

    Ayuso, Robert A.; Foley, Nora K.

    2003-01-01

    Detailed mineralogical, geochemical and radiogenic isotopic studies of iron-sulfide and secondary iron oxy-hydroxide minerals in natural bedrock in coastal Maine and New Hampshire test the link between arsenic-rich sulfide minerals in bedrock and secondary oxy-hydroxide minerals. Samples were selected from over 70 bedrock localities, including 22 within the regionally extensive and sulfide-mineral-rich Penobscot Formation and 10 associated with mineral deposits from coastal New Hampshire and Maine, and coupled with data from drill core collected at several sites including areas where well waters contain anomalous As abundances (e.g., Northport, ME). The data were used to establish a diversity of primary and secondary mineralogical hosts for arsenic in bedrock of this part of New England. The studies show that bedrock mineralogy is critical to contributing arsenic to groundwater and suggest a number of mineralogical pathways for arsenic that define weathering processes. The studies show that lead isotopic compositions of the sulfides and iron oxy-hydroxides overlap and establish a genetic link between the sulfides and secondary minerals. The data and interpretive results were presented at Arsenic in New England -- A multidisciplinary Scientific Conference, Manchester, New Hampshire, May 29-31, 2002, sponsored by the New Hampshire Consortium on Arsenic, are available in abstract and poster (full size = 84 by 36 inch sheet) formats.

  4. Arsenic solid-phase speciation and reversible binding in long-term contaminated soils.

    Science.gov (United States)

    Rahman, M S; Clark, M W; Yee, L H; Comarmond, M J; Payne, T E; Kappen, P; Mokhber-Shahin, L

    2017-02-01

    Historic arsenic contamination of soils occurs throughout the world from mining, industrial and agricultural activities. In Australia, the control of cattle ticks using arsenicals from the late 19th to mid 20th century has led to some 1600 contaminated sites in northern New South Wales. The effect of aging in As-mobility in two dip-site soil types, ferralitic and sandy soils, are investigated utilizing isotopic exchange techniques, and synchrotron X-ray adsorption spectroscopy (XAS). Findings show that historic soil arsenic is highly bound to the soils with >90% irreversibly bound. However, freshly added As (either added to historically loaded soils or pristine soils) has a significantly higher degree of As-accessibility. XAS data indicates that historic soil arsenic is dominated as Ca- (svenekite, & weilite), Al-(mansfieldite), and Fe- (scorodite) like mineral precipitates, whereas freshly added As is dominated by mineral adsorption surfaces, particularly the iron oxy-hydroxides (goethite and hematite), but also gibbsite and kaolin surfaces. SEM data further confirmed the presence of scorodite and mansfieldite formation in the historic contaminated soils. These data suggest that aging of historic soil-As has allowed neoformational mineral recrystallisation from surface sorption processes, which greatly reduces As-mobility and accessibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Sources and controls of Arsenic contamination in groundwater of Rajnandgaon and Kanker District, Chattisgarh Central India

    Science.gov (United States)

    Shukla, Dericks Praise; Dubey, C. S.; Singh, Ningthoujam P.; Tajbakhsh, M.; Chaudhry, M.

    2010-12-01

    SummaryA high concentration of Arsenic (As) contamination in ground water has been reported in the village of Kaudikasa in Rajnandgaon district, wherein around 10% of the population is suffering from As-borne diseases. The region does not share any demographic or geological similarity with the sedimentary aquifers of the Bengal Delta Plain in Eastern India, but represents an igneous terrain with elevated As concentrations in groundwater. There is limited information about the source of As in groundwater and its mobility constraints. In this area, almost all the wells are located in the granitic terrain with pegmatitic intrusions. Most of these wells are characterized by As concentration above the World Health Organization ( WHO, 1999) and the BIS (Bureau of Indian Standards) standards, with the highest being found in a well with more than 250 μg/L of As. Here we report petrographic studies of the granitic host rock and X-ray diffraction results that indicate that altered realgar (α-As 4S 4), para realgar (AsS), and/or tennantite (Cu 12As 4S 13), are the main mineral that contain As. This element is leached during the weathering and water-rock interactions. Microprobe analysis of the altered realgar grains of in pegmatitic intrusions of the host granite indicate 23-27 wt.% As. Remote sensing is useful to delineate the source of this contaminant, which appears to lie at the intersection of a mineralized NW-SE and N-S lineaments associated with the Kotri rift zone. These lineaments are structurally controlled as rifting followed by thrusting and other types of faulting caused left-lateral displacement of N-S Kotri lineament along a NW-SE fault plane showing sinistral shearing. This process caused water drainage in the areas to flow along these highly mineralized weak zones. Thus, the water becomes highly contaminated due to leaching of minerals at the intersection of these lineaments, clearly visible at two areas of high contamination that lie very near to this

  6. Evaluation of available data sources to prioritize parishes for arsenic monitoring and outreach related to private well drinking water.

    Science.gov (United States)

    Katner, Adrienne; Lackovic, Michelle; Streva, Kate; Paul, Vanessa; Trachtman, William Clay

    2015-01-01

    The objective of this assessment was to identify and evaluate data sets for use in the surveillance of arsenic hazards and private well drinking water use in Louisiana. Features, strengths, and limitations of the data sets are described, and prioritization criteria are applied to identify areas in need of further monitoring or outreach. Recent efforts have been made by the Environmental Public Health Tracking Network to evaluate the quality of private well water data for the purpose of supporting state and national surveillance activities. Like most states, Louisiana does not collect or mandate reporting of private well water quality data. Therefore, responding to public concerns about private well water quality requires an identification and evaluation of existing data. Data evaluated include measures of arsenic in groundwater and soil, private well water use, and biomonitoring results. The Environmental Protection Agency's Safe Drinking Water Information System and the US Geological Survey's Water Use data set were the most informative, nationally available data sets for conducting private well water arsenic surveillance. Three priority parishes were identified on the basis of a selection criteria, although all parishes require more private well sampling data. While the data reviewed enabled preliminary identification of parishes in need of monitoring and outreach, data limitations (particularly, a lack of statewide well water quality data) prevent a comprehensive evaluation of well water arsenic hazards and private well water use. A large number of unregistered wells further impede risk determination. Reliance on existing data sources is necessary, but development of metadata documentation is essential to prevent data misinterpretation. Increased outreach and policies to promote or mandate private well testing and reporting are needed to enable a comprehensive private well water tracking system.

  7. Relationship between long-term exposure to low-level arsenic in drinking water and the prevalence of abnormal blood pressure.

    Science.gov (United States)

    Zhang, Chuanwu; Mao, Guangyun; He, Suxia; Yang, Zuopeng; Yang, Wei; Zhang, Xiaojing; Qiu, Wenting; Ta, Na; Cao, Li; Yang, Hui; Guo, Xiaojuan

    2013-11-15

    Arsenic increases the risk and incidence of cardiovascular disease. To explore the impact of long-term exposure to low-level arsenic in drinking water on blood pressure including pulse pressure (PP) and mean arterial blood pressure (MAP), a cross-sectional study was conducted in 2010 in which the blood pressure of 405 villagers was measured, who had been drinking water with an inorganic arsenic content 63-3.35) increase in the group with >30-50 years of arsenic exposure and a 2.95-fold (95%CI: 1.31-6.67) increase in the group with >50 years exposure. Furthermore, the odds ratio for prevalence of abnormal PP and MAP were 1.06 (95%CI: 0.24-4.66) and 0.87 (95%CI: 0.36-2.14) in the group with >30-50 years of exposure, and were 2.46 (95%CI: 0.87-6.97) and 3.75 (95%CI: 1.61-8.71) for the group with >50 years exposure, compared to the group with arsenic exposure ≤ 30 years respectively. Significant trends for Hypertension (parsenic exposure population, and significantly increases with the duration of arsenic exposure.

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

    Directory of Open Access Journals (Sweden)

    Robin B. Harris

    2012-03-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  10. Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture.

    Science.gov (United States)

    Avelar, A C; Ferreira, W M; Pemberthy, D; Abad, E; Amaral, M A

    2016-05-01

    The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral. Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50pg WHO-TEQ g(-1)). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation. As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Arsenic pollution and fractionation in sediments and mine waste samples from different mine sites.

    Science.gov (United States)

    Larios, Raquel; Fernández-Martínez, Rodolfo; Álvarez, Rodrigo; Rucandio, Isabel

    2012-08-01

    A characterization of arsenic pollution and its associations with solid mineral phases in sediments and spoil heap samples from four different abandoned mines in Spain is performed. Three of them were mercury mines located in the same mining district, in the province of Asturias, and the other one, devoted to arsenic mining, is in the province of León. A sequential extraction procedure, especially developed for arsenic, was applied for the study of arsenic partitioning. Very high total arsenic concentrations ranging 300-67,000 mg·kg(-1) were found. Arsenic fractionation in each mine is broadly in accordance with the mineralogy of the area and the extent of the mine workings. In almost all the studied samples, arsenic appeared predominantly associated with iron oxyhydroxides, especially in the amorphous form. Sediments from cinnabar roasted piles showed a higher arsenic mobility as a consequence of an intense ore treatment, posing an evident risk of arsenic spread to the surroundings. Samples belonging to waste piles where the mining activity was less intense presented a higher proportion of arsenic associated with structural minerals. Nevertheless, it represents a long-term source of arsenic to the environment. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Guide to Sources: Term Paper Strategy.

    Science.gov (United States)

    White, Lucinda M.

    This two-page guide suggests an eight-step term paper research strategy for students using the Fogler Library at the University of Maine. The student is first guided to encyclopedias for overview articles with bibliographies, then directed to the card catalog; periodical indexes; and indexes for books, journal articles, and newspaper articles.…

  13. Long-term risks of metal contaminants in drinking water: a critical appraisal of guideline values for arsenic and vanadium

    Directory of Open Access Journals (Sweden)

    Riccardo Crebelli

    2012-12-01

    Full Text Available Metal contaminants in drinking water represent a relevant health issue in several areas of the world. In Italy, because of the geological features of the territory, high arsenic and vanadium are frequently reported in ground waters in concentrations above current guideline values. The implications for public health of the presence of contaminants above their legal limit are directly related to the biological basis of the guideline value. In the case of arsenic there are still major uncertainties in the mechanism of carcinogenesis which prevent a precise evaluation of long-term risks. Thus, the guideline value endorsed in the European Community (10 µg/L has to be considered as a pragmatic tool rather than a quality objective, bearing in mind that "every effort should be made to keep concentrations as low as reasonably possible" (WHO, 2011. A reverse situation holds for vanadium, for which a strict national limit (50 µg/L was previously proposed in consideration of data gaps, and for which new evidence indicated a less stringent health-based limit.

  14. Identifying sources and controlling factors of arsenic release in saline groundwater aquifers

    OpenAIRE

    Liu, C. -W.; Lu, K.-L.; Kao, Y.-H.; Wang, C.-J.; Maji, S.-K.; Lee, J.-F.

    2014-01-01

    An integrated hydrogeochemical study was carried out to realize the occurrence of arsenic (As) in a saline aquifer. Saline groundwater was mostly concentrated in the uppermost aquifer, and non-saline water was in the lower aquifer in the study area. High As concentrations were found in both the uppermost and lower aquifers. No correlation among salinity, well depth and As concentration was observed. Various forms of Fe oxyhydroxides were identified in the magnetic fractions,...

  15. Arsenic waste management: a critical review of testing and disposal of arsenic-bearing solid wastes generated during arsenic removal from drinking water.

    Science.gov (United States)

    Clancy, Tara M; Hayes, Kim F; Raskin, Lutgarde

    2013-10-01

    Water treatment technologies for arsenic removal from groundwater have been extensively studied due to widespread arsenic contamination of drinking water sources. Central to the successful application of arsenic water treatment systems is the consideration of appropriate disposal methods for arsenic-bearing wastes generated during treatment. However, specific recommendations for arsenic waste disposal are often lacking or mentioned as an area for future research and the proper disposal and stabilization of arsenic-bearing waste remains a barrier to the successful implementation of arsenic removal technologies. This review summarizes current disposal options for arsenic-bearing wastes, including landfilling, stabilization, cow dung mixing, passive aeration, pond disposal, and soil disposal. The findings from studies that simulate these disposal conditions are included and compared to results from shorter, regulatory tests. In many instances, short-term leaching tests do not adequately address the range of conditions encountered in disposal environments. Future research directions are highlighted and include establishing regulatory test conditions that align with actual disposal conditions and evaluating nonlandfill disposal options for developing countries.

  16. Environmental radiation safety source term evaluation program

    Energy Technology Data Exchange (ETDEWEB)

    Moss, O.R.; Filipy, R.E.; Cannon, W.C.; Craig, D.K.

    1977-04-01

    Plutonium-238 is currently used in the form of a pure refractory oxide as a power source on a number of space vehicles that have already been or will be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere and impact with the earth's surface without releasing any plutonium, the possibility of such an event can never be absolutely excluded. Three separate tasks were undertaken in this study. The interactions between soils and /sup 238/PuO/sub 2/ aerosols which might be created in a space launch about environment were examined. Aging of the plutonium-soil mixture under a humid atmosphere showed a trend toward the slow coagulation of two dilute aerosols. Studies on marine animals were conducted to assess the response of /sup 238/PuO/sub 2/ pellets to conditions found 60 feet below the ocean surface. Ultrafilterability studies measured the solubility of /sup 238/PuO/sub 2/ as a function of time, temperature, suspension concentration and molality of solvent. (ACR)

  17. Short-term arsenic exposure reduces diatom cell size in biofilm communities.

    Science.gov (United States)

    Barral-Fraga, Laura; Morin, Soizic; Rovira, Marona D M; Urrea, Gemma; Magellan, Kit; Guasch, Helena

    2016-03-01

    Arsenic (As) pollution in water has important impacts for human and ecosystem health. In freshwaters, arsenate (As(V)) can be taken up by microalgae due to its similarity with phosphate molecules, its toxicity being aggravated under phosphate depletion. An experiment combining ecological and ecotoxicological descriptors was conducted to investigate the effects of As(V) (130 μg L(-1) over 13 days) on the structure and function of fluvial biofilm under phosphate-limiting conditions. We further incorporated fish (Gambusia holbrooki) into our experimental system, expecting fish to provide more available phosphate for algae and, consequently, protecting algae against As toxicity. However, this protection role was not fully achieved. Arsenic inhibited algal growth and productivity but not bacteria. The diatom community was clearly affected showing a strong reduction in cell biovolume; selection for tolerant species, in particular Achnanthidium minutissimum; and a reduction in species richness. Our results have important implications for risk assessment, as the experimental As concentration used was lower than acute toxicity criteria established by the USEPA.

  18. An insight of environmental contamination of arsenic on animal health

    OpenAIRE

    Paramita Mandal

    2017-01-01

    The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. Exposure to arsenic is mainly via intake of food and drinking water, food being the most important source in most populations. Although adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues and is even increasing in some areas. Long-term exposure to arsenic in drinking-water is mainly related to increased risks of skin canc...

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

    Science.gov (United States)

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

    2013-11-15

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

  20. Assessment of arsenic, fluoride, bacteria, and other contaminants in drinking water sources for rural communities of Kasur and other districts in Punjab, Pakistan.

    Science.gov (United States)

    Arshad, Nasima; Imran, Saiqa

    2017-01-01

    High levels of arsenic contamination in drinking water of two villages, Badarpur and Ibrahimabad of district Kasur, central Punjab, Pakistan is reported first time in present studies. Groundwater quality situation was found to be impaired when samples of different rural areas of district Kasur were monitored according to Pakistan Standards and Quality Control Authority (PSQCA) for all significant water quality constituents and analyzed for trace elements, physico-chemical, and microbiological parameters. Out of 35water sources, 97 % were found unsafe and only 3 % of the sources were within safe limits. High concentrations of arsenic, fluoride, and bacteria were found in 91, 74, and 77 % sources of drinking water, respectively. Very high concentrations of arsenic ranging 58-3800 μg/L were found in the water samples obtained from Badarpur and Ibrahimabad. A decrease in water contamination was observed with increase in source depth. The health issues like arsenicosis and skeletal/dental flourosis were observed in the residents of the monitored areas. Drinking water quality conditions of some rural areas of northen and southern districts of Punjab was also analyzed and compared with Kasur district. High levels of nitrates were found in the samples of Islamabad and Rawalpindi, while high levels of arsenic, iron, fluoride, and TDS were found in Bahawalpur district. Graphical abstract ᅟ.

  1. Effects of source term characteristics on Off Site consequence

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seok Jung; Ahn, Kwang Il [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Off site consequence analysis in Level 3 PSA is mainly affected by source term release characteristics of nuclear plant. The severe accident analysis codes for quantifying the source term release characteristics such as MELCOR and MAAP provide detailed information of these characteristics to assess the off site consequence. The aforementioned characteristics, however, have not been considered in the consequence analysis of domestic plants because of large uncertainty in these characteristics so far. Recently, the USNRC SOARCA report showed an approach to utilize detailed source term characteristics provided by MELCOR code to quantify the off site consequence more realistically. Main purpose of this study is to assess effects of the MELCOR source term characteristics on the off site consequence analysis of a domestic nuclear power plant, in a similar fashion to the SOARCA approach. Among many features characterizing source term, the most important one is to determine initial and boundary conditions of atmospheric dispersion such as:- Release amounts of source term - Release time and duration Moreover, plumes features (i.e., radiation clouds) affect atmospheric dispersion that shapes plume characteristics as follows: - Initial dimension of plumes - Plume rise - Deposition of radioactive materials during dispersion Although the current severe accident codes have some limitation in providing the entire source term release characteristics needed in the consequence analysis, the essential information for these features could be obtained from these codes. It is noted that the typical approaches, which generate source term information for the consequence analysis from the severe accident codes, should require a technical manipulation by the experts of consequence analysis. The present effort focused on an identification of insights to utilize source term characteristics of the severe accident codes.

  2. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Pete Lowry

    2012-02-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  3. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Pete Lowry

    2012-01-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  4. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Pete Lowry

    2012-10-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  5. Source term analyses under severe accidents for KNGR

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yong Mann; Park, Soo Yong

    2001-03-01

    In this study, in-containment source term for LOFW (Loss of Feed Water), which has appeared the most frequent core melt accident, is calculated and compared with NUREG-1465 source term. This study provides not only new source term data using MELCOR1.8.4 and its state-of-the-art models but also evaluating basis of KNGR design and its mitigation capability under severe accidents. As the selected accident is identical with LOFW-S17, which has been analyzed using MAAP by KEPCO with only difference of 2 SITs, mutual comparison of the results is especially expected.

  6. Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Avelar, A.C., E-mail: avelara@ufmg.br [Department of Animal Sciences, Veterinary School, Universidad de Federal de Minas Gerais Avenida Antonio Carlos, 6627 Campus UFMG, Belo Horizonte (Brazil); Ferreira, W.M. [Department of Animal Sciences, Veterinary School, Universidad de Federal de Minas Gerais Avenida Antonio Carlos, 6627 Campus UFMG, Belo Horizonte (Brazil); Pemberthy, D. [Spanish Council for Scientific Research (CSIC), Institute of Environmental Assessment and Water Research, C/ Jordi Girona 18-26, 08034 Barcelona (Spain); Universidad de Antioquia, Departamento de Ingeniería Química, Facultad de Ingeniería, Grupo Catálisis Ambiental, Calle 70 No. 52-2, Medellín (Colombia); Abad, E. [Spanish Council for Scientific Research (CSIC), Institute of Environmental Assessment and Water Research, C/ Jordi Girona 18-26, 08034 Barcelona (Spain); Amaral, M.A. [Department of Animal Sciences, Veterinary School, Universidad de Federal de Minas Gerais Avenida Antonio Carlos, 6627 Campus UFMG, Belo Horizonte (Brazil)

    2016-05-01

    The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral. Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50 pg WHO-TEQ g{sup −1}). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation. As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field. - Highlights: • PCDD/Fs dl- PCBs is not a matter since levels below the LOD in phosphate materials subject of study. • Significant accumulation of As and U in Limestone. Th was originally found in dicalcium phosphate. • High concentration of U in dicalcium phosphate suggests that a special attention should be paid.

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

    Science.gov (United States)

    Smith, A H; Lingas, E O; Rahman, M

    2000-01-01

    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 micrograms 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, the experience in Bangladesh shows that groundwater sources throughout the world that are used for drinking-water should be tested for arsenic.

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

    Science.gov (United States)

    Smith, A. H.; Lingas, E. O.; Rahman, M.

    2000-01-01

    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 micrograms 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, the experience in Bangladesh shows that groundwater sources throughout the world that are used for drinking-water should be tested for arsenic. PMID:11019458

  9. The latest results from source term research. Overview and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, Luis E. [Centro de Investigaciones Energeticas Medio Ambientales y Tecnologica (CIEMAT), Madrid (Spain); Haste, Tim [Centre d' Etudes de Cadarache, Paul-Lez-Durance (France). Institut de Radioprotection et de Surete Nucleaire (IRSN); Kaerkelae, Teemu [VTT Technical Research Centre of Finland Ltd, Espoo (Finland)

    2016-12-15

    Source term research has continued internationally for more than 30 years, increasing confidence in calculations of the potential radioactive release to the environment after a severe reactor accident. Important experimental data have been obtained, mainly under international frameworks such as OECD/NEA and EURATOM. Specifically, Phebus FP provides major insights into fission product release and transport. Results are included in severe accident analysis codes. Data from international projects are being interpreted with a view to further improvements in these codes. This paper synthesizes the recent main outcomes from source term research on these topics, and on source term mitigation. It highlights knowledge gaps remaining and discusses ways to proceed. Aside from this further knowledge-driven research, there is consensus on the need to assess the source term predictive ability of current system codes, taking account of scale-up from experiment to reactor conditions.

  10. Source Term Model for an Array of Vortex Generator Vanes

    Science.gov (United States)

    Buning, P. G. (Technical Monitor); Waithe, Kenrick A.

    2003-01-01

    A source term model was developed for numerical simulations of an array of vortex generators. The source term models the side force created by a vortex generator being modeled. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on a local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low-profile vortex generator vane, which is only a fraction of the boundary layer thickness, over a flat plate. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data.

  11. Revised accident source terms for light-water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Soffer, L. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  12. Review of SFR In-Vessel HCDA Source Terms

    Energy Technology Data Exchange (ETDEWEB)

    Suk, S. D.; Ha, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    An effort has been made in this study to search for and review the literatures on the studies of the phenomena related to the release of radionuclides and aerosols to the reactor containment of the sodium fast reactor (SFR) plants ( i.e., in-vessel source term. Review work is focused on the experimental programs to investigate the phenomena related to determining the source terms, with a brief review on supporting analytical models and computer programs. As a result of the severe accidents experienced at TMI and Chernobyl, much work has been done on the energetic CDA bubble source term (also called 'primary' or 'instantaneous' source term) defined as the amount of radioactive material released from the reactor vessel to the containment due to the rapid expansion of fuel or sodium leading to a failure of the vessel head. In this study, the research programs conducted to investigate the CDA (core disruptive accident) bubble behavior in the sodium pool for determining 'primary' or 'instantaneous' source term are introduced. The research programs to investigate the release and transport of fission products(FPs) and aerosols in the reactor containment (i.e., in-containment source term) are not described in this study.

  13. Arsenic and heavy metals contamination, risk assessment and their source in drinking water of the Mardan District, Khyber Pakhtunkhwa, Pakistan.

    Science.gov (United States)

    Gul, Nida; Shah, Mohammad Tahir; Khan, Sardar; Khattak, Nimat Ullah; Muhammad, Said

    2015-12-01

    The present study was conducted to investigate the physico-chemical characteristics in drinking water of Mardan District, Pakistan. Furthermore, water quality was evaluated for the risk assessment of arsenic and heavy metals (HMs) and their contamination sources. Representative groundwater samples of shallow and deep sources were collected in the study area. These samples were analyzed for physical parameters, anions, light metals (LMs) and HMs. Results were compared with the drinking water guideline values set by the World Health Organization and the US Environmental Protection Agency. Average concentrations of anions, LMs and HMs were found within the maximum allowable contaminant levels except for bicarbonates, Fe, Cu, and Pb. Results revealed that hazard quotients >1 were observed for shallow groundwater for 10% samples only, suggesting potential health risk from water consumption. Correlation analysis and principal component analysis showed a relationship among various physico-chemical parameters in both shallow and deep groundwater. Statistical analyses suggested the geogenic and anthropogenic sources for possible enhancement of various physico-chemical parameters in the aquifer system of the study area.

  14. Risk Assessment of Arsenic in Rice Cereal and Other Dietary Sources for Infants and Toddlers in the U.S.

    Science.gov (United States)

    Shibata, Tomoyuki; Meng, Can; Umoren, Josephine; West, Heidi

    2016-03-25

    Currently, there are no set standards or quantitative guidelines available in the U.S. for arsenic levels in rice cereal, one of the most common first solid foods for infants. The objective of this study was to evaluate whether the detected levels of inorganic arsenic (As(i)) in rice cereal in the U.S. market are safe for consumption by infants and toddlers. A risk assessment was conducted based on literature reviews of the reported As(i) in rice cereal from the U.S. Food and Drug Administration's (FDA) survey and the recommended daily intake of rice cereal by body weight, for infants and toddlers between four and 24 months old. As a part of risk management, a maximum contaminant level (MCL) for Asi in rice cereal was computed considering overall exposure sources including drinking water, infant formula, and other infant solid foods. Hazard quotients (HQs) for acute and chronic exposures were calculated based on the U.S. Agency for Toxic Substances and Disease Registry's (ATSDR) Minimal Risk Level (MRL)(acute) (5.0 × 10(-3) mg/kg/day) and MRL(chronic) (3.0 × 10(-4) mg/kg/day). A cancer slope or potency factor of 1.5 mg/kg/day was used to predict an incremental lifetime cancer risk (ILCR). Exposure assessment showed that the largest source of As(i) for infants and toddlers between four and 24 months old was rice cereal (55%), followed by other infant solid food (19%), and drinking water (18%). Infant formula was the smallest source of As(i) for babies (9%) at the 50th percentile based on Monte Carlo simulations. While HQ(acute) were consistently below 1.0, HQ(chronic) at the 50 and 75th percentiles exceeded 1.0 for both rice cereal and total sources. ILCR ranged from 10(-6) (50th) to 10(-5) (75th percentile). MCLs for As(i) in rice cereal ranged from 0.0 (chronic) to 0.4 mg/kg (acute exposures).

  15. Arsenic pollution and fractionation in sediments and mine waste samples from different mine sites

    Energy Technology Data Exchange (ETDEWEB)

    Larios, Raquel; Fernandez-Martinez, Rodolfo [Unidad de Espectroscopia, Division de Quimica, Departamento de Tecnologia, CIEMAT. Av. Complutense, 40, E-28040 Madrid (Spain); Alvarez, Rodrigo [Dpto. de Explotacion y Prospeccion de Minas, Universidad de Oviedo, ETS de Ingenieros de Minas, C/Independencia, 13, E-33004 Oviedo (Spain); Rucandio, Isabel, E-mail: isabel.rucandio@ciemat.es [Unidad de Espectroscopia, Division de Quimica, Departamento de Tecnologia, CIEMAT. Av. Complutense, 40, E-28040 Madrid (Spain)

    2012-08-01

    A characterization of arsenic pollution and its associations with solid mineral phases in sediments and spoil heap samples from four different abandoned mines in Spain is performed. Three of them were mercury mines located in the same mining district, in the province of Asturias, and the other one, devoted to arsenic mining, is in the province of Leon. A sequential extraction procedure, especially developed for arsenic, was applied for the study of arsenic partitioning. Very high total arsenic concentrations ranging 300-67,000 mg{center_dot}kg{sup -1} were found. Arsenic fractionation in each mine is broadly in accordance with the mineralogy of the area and the extent of the mine workings. In almost all the studied samples, arsenic appeared predominantly associated with iron oxyhydroxides, especially in the amorphous form. Sediments from cinnabar roasted piles showed a higher arsenic mobility as a consequence of an intense ore treatment, posing an evident risk of arsenic spread to the surroundings. Samples belonging to waste piles where the mining activity was less intense presented a higher proportion of arsenic associated with structural minerals. Nevertheless, it represents a long-term source of arsenic to the environment. - Highlights: Black-Right-Pointing-Pointer Arsenic fractionation in sediments from different mining areas is evaluated. Black-Right-Pointing-Pointer A sequential extraction scheme especially designed for arsenic partitioning is applied. Black-Right-Pointing-Pointer As associations with mineral pools is in accordance to the mineralogy of each area. Black-Right-Pointing-Pointer As distribution and mobility in each area depends on the extent of mining activity. Black-Right-Pointing-Pointer As occurs mainly associated with amorphous iron oxyhydroxides in all samples.

  16. Selection of models to calculate the LLW source term

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M. (Brookhaven National Lab., Upton, NY (United States))

    1991-10-01

    Performance assessment of a LLW disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). In turn, many of these physical processes are influenced by the design of the disposal facility (e.g., infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This document provides a brief overview of disposal practices and reviews existing source term models as background for selecting appropriate models for estimating the source term. The selection rationale and the mathematical details of the models are presented. Finally, guidance is presented for combining the inventory data with appropriate mechanisms describing release from the disposal facility. 44 refs., 6 figs., 1 tab.

  17. Relapsed APL patient with variant NPM-RARalpha fusion responded to arsenic trioxide-based therapy and achieved long-term survival.

    Science.gov (United States)

    Chen, Yan; Gu, Ling; Zhou, Chenyan; Wu, Xueqiang; Gao, Ju; Li, Qiang; Zhu, Yiping; Jia, Cangsong; Ma, Zhigui

    2010-05-01

    The t(5;17)/NPM-RARalpha is the second variant chromosomal translocation in acute promyelocytic leukemia (APL) to be characterized and also the second most plentiful variant translocation. So far, there is a lack of information on the effectiveness of arsenic trioxide (ATO) in relapsed APL with variant RARalpha chimera including t(5;17)/NPM-RARalpha. We report here a long-term survived APL patient with variant NPM-RARalpha fusion who relapsed four times and each time responded well to ATO or ATO-based re-induction therapy. The patient had received a total of more than 3,500 mg of ATO, but showed no obvious arsenic-related toxicities. This case illustrates the long-term efficiency and safety of ATO-based therapy not only in newly diagnosed APL, but also in relapsed APL including those with variant translocations.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. Incorporation Behaviour of Arsenic and Phosphorus in GaAsP/GaAs Grown by Solid Source Molecular Beam Epitaxy with a GaP Decomposition Source

    Institute of Scientific and Technical Information of China (English)

    WU Shu-Dong; GUO Li-Wei; WANG Wen-Xin; LI Zhi-Hua; NIU Ping-Juan; HUANG Qi; ZHOU Jun-Ming

    2005-01-01

    @@ The incorporation behaviour of arsenic and phosphorus in the GaAsP ternary alloy under phosphorus-rich conditions is studied based on the incorporation coeffcient model and the growth diffusion model combined with the alloy composition data obtained by high resolution x-ray diffraction analysis.It is found that As adatoms have longer surface lifetime and longer migration length than those of P adatoms, which leads to an arsenic incorporation efficiency much higher than that of phosphorous.With the increase of arsenic flux, the surface lifetime of arsenic adatoms decreases due to the competition of As adatoms.The detailed analysis and discussion are given here.

  1. Charge-exchange source terms in magnetohydrodynamic plasmas

    Science.gov (United States)

    DeStefano, Anthony M.; Heerikhuisen, Jacob

    2017-05-01

    In the modeling of space plasma environments, source terms are often used to couple separate species of particles and/or fluids. There have been many techniques developed over the years to make such coupling more tractable while maintaining maximum physical fidelity. In our current application we use the formalism of the Boltzmann collision integral to compute source terms due to charge-exchange events in the heliosphere. The charge-exchange cross sections often encountered in heliospheric interactions can be fit to laboratory data, but in most cases cannot be directly integrated over analytically. Therefore, researchers often employ various levels of approximation, either semi-analytic or numerical. We explore several assumptions to the charge-exchange source term integrals, namely using Maxwellian velocity spaces for like-mass species and either hard-sphere, power-law, or exact forms of the cross section.

  2. Simultaneously evaluate the toxic levels of fluoride and arsenic species in underground water of Tharparkar and possible contaminant sources: a multivariate study.

    Science.gov (United States)

    Brahman, Kapil Dev; Kazi, Tasneem Gul; Afridi, Hassan Imran; Naseem, Shahid; Arain, Sadia Sadaf; Wadhwa, Sham Kumar; Shah, Faheem

    2013-03-01

    The present study investigated total arsenic (tAs), inorganic arsenic (iAs) species and fluoride ion (F(-)) contamination in underground water of Mithi and Nangarparkar subdistricts of Tharparkar, Pakistan. Statistical parameters, principal component analysis, cluster analysis, sodium absorption ratio and saturation indices (SI) were used to detect interrelation and sources of concentration of tAs, iAs species (As(3+) and As(5+)), F(-) and others physicochemical parameters. The concentration of As(3+) was measured by cloud point extraction using ammonium pyrrolidinedithiocarbamate (APDC) as complexing reagent, while inorganic arsenic (iAs) was determined by solid phase extraction, using titanium dioxide. The positive correlation was observed between F(-) contents with As species and other major ions, found in the underground water of the study area. The resulted data indicated that underground water samples of two areas of Tharparkar were severely contaminated with arsenic (0.100-3.83 mg/L) and fluoride ion (13.8-49.3mg/L), which were exceeded the World Health Organization provisional guideline values, 0.01 mg/L and 1.5mg/L, respectively. The SI of fluorite and calcite in the underground water samples showed that most of the samples were oversaturated with respect to calcite and fluorite. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. 云南阳宗海砷的分布与来源%Distribution and Sources of Arsenic in Yangzonghai Lake,China

    Institute of Scientific and Technical Information of China (English)

    张玉玺; 向小平; 张英; 陈玺; 刘景涛; 王金翠; 张媛静; 孙继朝

    2012-01-01

    By collecting water and sediment samples from Yangzonghai Lake and analyzing the total amount and speciation of arsenic,the spatial distribution of arsenic in surface water and sediments was analyzed,the current status of arsenic pollution were estimated,the anthropogenic contribution rate and the arsenic reserve in the lake were calculated respectively.Meanwhile,the sources of arsenic were investigated.The results indicated that the total arsenic content in Yangzonghai Lake was 71.96-101.2 μg·L-1 in April,2010,and increased slightly with depth.Dissolved arsenic content was 68.14-96.72 μg·L-1,with As(Ⅲ) accounting for 32%.The health risk level of arsenic in the water was 4.77×10^-4-6.66×10^-4 a^-1,posing a considerable threat to the surrounding environment.Arsenic content in sediments lied between 6.05-396.49 mg·kg^-1.In sediments at the depths of 0-2,2-4,4-6,6-8 and 8-10 cm,the average arsenic contents were 155.66,52.01,29.78,19.22 and 17.52 mg·kg^-1 respectively.Arsenic in sediments at 0-2 cm had the highest accumulation degree,with the maximum geoaccumulation index up to 5.At the deeper depths,the accumulation degree of arsenic significantly lowered.The sequence of arsenic average contents of seven forms in sediments in the descending order is residual fraction,humic acids fraction,oxide fraction,strong organic fraction,ion exchange fraction,water soluble fraction and carbonate fraction.With increase of sediments depths,the percentage of bioavailable arsenic decreased,and the percentage of residual fraction arsenic increased rapidly.The anthropogenic contribution rate of arsenic in sediments was the highest at 0-2 cm depth,with average of 81.94%.This rate was much lower at the deeper depths.Currently,the total arsenic reserve in water and sediments of Yangzonghai Lake was 70.65 t,of which 82.68% was contributed by human activities.The phosphate fertilizer plant on the south bank made the greatest contribution to arsenic accumulation in Yangzonghai Lake

  4. Flowsheets and source terms for radioactive waste projections

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W. (comp.)

    1985-03-01

    Flowsheets and source terms used to generate radioactive waste projections in the Integrated Data Base (IDB) Program are given. Volumes of each waste type generated per unit product throughput have been determined for the following facilities: uranium mining, UF/sub 6/ conversion, uranium enrichment, fuel fabrication, boiling-water reactors (BWRs), pressurized-water reactors (PWRs), and fuel reprocessing. Source terms for DOE/defense wastes have been developed. Expected wastes from typical decommissioning operations for each facility type have been determined. All wastes are also characterized by isotopic composition at time of generation and by general chemical composition. 70 references, 21 figures, 53 tables.

  5. Arsenic in Water Resources of the Southern Pampa Plains, Argentina

    Directory of Open Access Journals (Sweden)

    Juan D. Paoloni

    2009-01-01

    Full Text Available Confronted with the need for accessible sources of good quality water and in view of the fact that the threat to public health posed by arsenic occurs mainly through the ingestion of contaminated drinking water, the presence and distribution of arsenic was evaluated in the southern Pampa Plains of Bahía Blanca district in Argentina. The findings show variable concentrations of arsenic in a complex distribution pattern. Complementary information is provided on the behavior of the groundwater resource and its salinity in terms of dissolved ions. Groundwater is the most severely affected, 97% of the samples exceeding the guideline value for arsenic in drinking water as recommended by the WHO (Guidelines for Drinking Water Quality, 2004. and showing maximum concentrations of up to 0.30 mg/L. Informing those responsible for preventive medicine and alerting the community at large will facilitate measures to mitigate exposure and ensure the safety of drinking water.

  6. Source and distribution of naturally occurring arsenic in groundwater from Alberta’s Southern Oil Sands Regions

    Energy Technology Data Exchange (ETDEWEB)

    Moncur, Michael C.; Paktunc, Dogan; Birks, S. Jean; Ptacek, Carol J.; Welsh, Brent; Thibault, Yves (CanmetMINING); (AER); (Alberta Innov.); (Waterloo)

    2016-06-10

    Arsenic (As) concentrations as high as 179 μg/L have been observed in shallow groundwater in the Alberta’s Southern Oil Sand Regions. The geology of this area of Alberta includes a thick cover (up to 200 m) of unconsolidated glacial deposits, with a number of regional interglacial sand and gravel aquifers, underlain by marine shale. Arsenic concentrations observed in 216 unconsolidated sediment samples ranged from 1 and 17 ppm. A survey of over 800 water wells sampled for As in the area found that 50% of the wells contained As concentrations exceeding drinking water guidelines of 10 μg/L. Higher As concentrations in groundwater were associated with reducing conditions. Measurements of As speciation from 175 groundwater samples indicate that As(III) was the dominant species in 74% of the wells. Speciation model calculations showed that the majority of groundwater samples were undersaturated with respect to ferrihydrite, suggesting that reductive dissolution of Fe-oxyhydroxides may be the source of some As in groundwater. Detailed mineralogical characterization of sediment samples collected from two formations revealed the presence of fresh framboidal pyrite in the deeper unoxidized sediments. Electron microprobe analysis employing wavelength dispersive spectrometry indicated that the framboidal pyrite had variable As content with an average As concentration of 530 ppm, reaching up to 1840 ppm. In contrast, the oxidized sediments did not contain framboidal pyrite, but exhibited spheroidal Fe-oxyhydroxide grains with elevated As concentrations. The habit and composition suggest that these Fe-oxyhydroxide grains in the oxidized sediment were an alteration product of former framboidal pyrite grains. X-ray absorption near edge spectroscopy (XANES) indicated that the oxidized sediments are dominated by As(V) species having spectral features similar to those of goethite or ferrihydrite with adsorbed As, suggesting that Fe-oxyhydroxides are the dominant As carriers

  7. Identifying sources and controlling factors of arsenic release in saline groundwater aquifers

    Directory of Open Access Journals (Sweden)

    C.-W. Liu

    2013-08-01

    Full Text Available An integrated hydrogeochemical study is carried out to realize the occurrence of arsenic (As in a saline aquifer. Saline groundwater was mostly concentrated in the uppermost aquifer and non-saline water was in the lower aquifer in the study area. High As concentrations were found in both uppermost and lower aquifers. No correlation among salination, well depth and As concentration was observed. Both reducing and oxidizing forms of Fe oxyhydroxides were identified in the magnetic fractions, which were concentrated by high gradient magnetic separation (HGMS technique, revealing that the redox cycling of Fe occurred in the subsurface. High levels of Fe, HCO3-, DOC and NH4+ concentrations accompanying alkaline pH in the As-rich groundwater were consistent with the mechanism triggered by the microbial-mediated reductive dissolution of Fe oxyhydroxides. A threshold value of 50 μg L−1. As concentration was used as an indicator for identification of active proceeding reductive dissolution of As-bearing Fe oxyhydroxides in the saline aquifer. Desorption behaviors of As were relevant to its valence in the sediments and the co-existence of anions. Experimental and numerical results showed that additions of Cl- and SO42-, which represented the main anions of saline water, had minor effect on leaching sedimentary As. Although bicarbonate addition resulted in less As desorption than that of phosphate on a molar basis, the contribution of bicarbonate to the total release of As was greater than phosphate due to the much higher concentration of bicarbonate in groundwater and the associated microbial mediation. Collectively, the chemical effect of saline water on the As-release to groundwater is mild in the coastal aquifer.

  8. Speciation analysis of arsenic in groundwater from Inner Mongolia with an emphasis on acid-leachable particulate arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Gong Zhilong [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Lu Xiufen [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Watt, Corinna [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Wen Bei [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); He Bin [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada); Mumford, Judy [National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Human Studies Division, Epidemiology and Biomarkers Branch, Research Triangle Park, NC 27711 (United States); Ning Zhixiong [Ba Men Anti-Epidemic Station, Lin He, Inner Mongolia (China); Xia Yajuan [Inner Mongolia Center for Endemic Disease Control and Research, Huhhot, Inner Mongolia (China); Le, X. Chris [Department of Public Health Sciences, University of Alberta, 10-102 Clinical Sciences Building, Edmonton, Alta., T6G 2G3 (Canada)]. E-mail: xc.le@ualberta.ca

    2006-01-05

    Arsenic in drinking water affects millions of people around the world. While soluble arsenic is commonly measured, the amount of particulate arsenic in drinking water has often been overlooked. We report here determination of the acid-leachable particulate arsenic and soluble arsenicals in well water from an arsenic-poisoning endemic area in Inner Mongolia, China. Water samples (583) were collected from 120 wells in Ba Men, Inner Mongolia, where well water was the primary drinking water source. Two methods were demonstrated for the determination of soluble arsenic species (primarily inorganic arsenate and arsenite) and total particulate arsenic. The first method used solid phase extraction cartridges and membrane filters to separate arsenic species on-site, followed by analysis of the individual arsenic species eluted from the cartridges and filters. The other method uses liquid chromatography separation with hydride generation atomic fluorescence detection to determine soluble arsenic species. Analysis of acidified water samples using inductively coupled plasma mass spectrometry provided the total arsenic concentration. Arsenic concentrations in water samples from the 120 wells ranged from <1 to {approx}1000 {mu}g L{sup -1}. On average, particulate arsenic accounted for 39 {+-} 38% (median 36%) of the total arsenic. In some wells, particulate arsenic was six times higher than the soluble arsenic concentration. Particulate arsenic can be effectively removed using membrane filtration. The information on particulate and soluble arsenic in water is useful for optimizing treatment options and for understanding the geochemical behavior of arsenic in groundwater.

  9. Literature study of source term research for PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Sponton, L.L.; NiIsson, Lars

    2001-04-01

    A literature survey has been carried out in support of ongoing source term calculations with the MELCOR code of some severe accident scenarios for the Swedish Ringhals 2 pressurised water reactor (PWR). The research in the field of severe accidents in power reactors and the source term for subsequent release of radioisotopes was intensified after the Harrisburg accident and has produced a large amount of reports and papers. This survey was therefore limited to research concerning PWR type of reactors and with emphasis on papers related to MELCOR code development. A background is given, relating to some historic documents, and then more recent research after 1990 is reviewed. Of special interest is the ongoing PMbus-programme which is creating new and important results of benefit to the code development and validation of, among others, the MELCOR code. It is concluded that source term calculations involve simulation of many interacting complex physical phenomena, which result in large uncertainties The research has, however, over the years led to considerable improvements Thus has the uncertainty in source term predictions been reduced one to two orders of magnitude from the simpler codes in the early 1980-s to the more realistic codes of today, like MELCOR.

  10. Alternative Source Terms for SWAN in the Coastal Region

    NARCIS (Netherlands)

    Salmon, J.E.; Holthuijsen, L.H.; Smit, P.B.; Van Vledder, G.P.; Zijlema, M.

    2014-01-01

    This paper presents the application of new source terms in SWAN for the dominant water wave physics in the coastal zone: depth-induced breaking and triad wave-wave interactions. We present results demonstrating increased modelling skill in the prediction of bulk wave parameters e.g. significant wave

  11. BWR ASSEMBLY SOURCE TERMS FOR WASTE PACKAGE DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    T.L. Lotz

    1997-02-15

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide boiling water reactor (BWR) assembly radiation source term data for use during Waste Package (WP) design. The BWR assembly radiation source terms are to be used for evaluation of radiolysis effects at the WP surface, and for personnel shielding requirements during assembly or WP handling operations. The objectives of this evaluation are to generate BWR assembly radiation source terms that bound selected groupings of BWR assemblies, with regard to assembly average burnup and cooling time, which comprise the anticipated MGDS BWR commercial spent nuclear fuel (SNF) waste stream. The source term data is to be provided in a form which can easily be utilized in subsequent shielding/radiation dose calculations. Since these calculations may also be used for Total System Performance Assessment (TSPA), with appropriate justification provided by TSPA, or radionuclide release rate analysis, the grams of each element and additional cooling times out to 25 years will also be calculated and the data included in the output files.

  12. Disposal Unit Source Term (DUST) data input guide

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M. [Brookhaven National Lab., Upton, NY (United States)

    1993-05-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). The computer code DUST (Disposal Unit Source Term) has been developed to model these processes. This document presents the models used to calculate release from a disposal facility, verification of the model, and instructions on the use of the DUST code. In addition to DUST, a preprocessor, DUSTIN, which helps the code user create input decks for DUST and a post-processor, GRAFXT, which takes selected output files and plots them on the computer terminal have been written. Use of these codes is also described.

  13. Mechanisms for dose retention in conformal arsenic doping using a radial line slot antenna microwave plasma source

    Science.gov (United States)

    Ueda, Hirokazu; Ventzek, Peter L. G.; Oka, Masahiro; Kobayashi, Yuuki; Sugimoto, Yasuhiro

    2015-06-01

    Topographic structures such as Fin FETs and silicon nanowires for advanced gate fabrication require ultra-shallow high dose infusion of dopants into the silicon subsurface. Plasma doping meets this requirement by supplying a flux of inert ions and dopant radicals to the surface. However, the helium ion bombardment needed to infuse dopants into the fin surface can cause poor dose retention. This is due to the interaction between substrate damage and post doping process wet cleaning solutions required in the front end of line large-scale integration fabrication. We present findings from surface microscopy experiments that reveal the mechanism for dose retention in arsenic doped silicon fin samples using a microwave RLSA™ plasma source. Dilute aqueous hydrofluoric acid (DHF) cleans by themselves are incompatible with plasma doping processes because the films deposited over the dosed silicon and ion bombardment damaged silicon are readily removed. Oxidizing wet cleaning chemistries help retain the dose as silica rich over-layers are not significantly degraded. Furthermore, the dosed retention after a DHF clean following an oxidizing wet clean is unchanged. Still, the initial ion bombardment energy and flux are important. Large ion fluxes at energies below the sputter threshold and above the silicon damage threshold, before the silicon surface is covered by an amorphous mixed phase layer, allow for enhanced uptake of dopant into the silicon. The resulting dopant concentration is beyond the saturation limit of crystalline silicon.

  14. The iron, aluminate and jarosite deposits in Riazas area as potential source of arsenic in groundwater; Los yacimientos de hierro, alunita y jarosita de la zona de Riaza como posible origen del arsenico en las aguas subterraneas

    Energy Technology Data Exchange (ETDEWEB)

    Leal Meca, M.; Lilo Ramos, J.

    2009-07-01

    Arsenic in concentrations above the legal limit of 10 {mu}g/l has been detected in groundwaters of the Duero Cenozoic Basin. The origin of arsenic is related to sedimentary units with arsenic content above the background value of 28.5 mg/kg. Thus, iron-rich deposits located at the base of Cenozoic succession may constitute a potential source of arsenic in the groundwaters. Three outcrops of iron-rich conglomerates in the Riazas area of Segovia province (one in El Negredo and two in Madriguera) have been studied to determine the significance of these materials as a potential source of arsenic in groundwater. These outcrops occur above an unconformity separating them from strongly altered Paleozoic slates, rich in alunite and jarosite. The work is based in geochemical (trace elements detection by INAA) and mineralogical analyses (through XRD-EDAX and ESEM) of 18 samples of altered slates and materials of ferriferrous deposits. Besides, 3 water samples from springs have subjected to hydrochemical analysis to establish major ionic species and trace elements. Although mineralogical study reveals that arsenic occurs in iron oxides and high arsenic concentrations have been identified in rocks of El Negredo (up to 361 mg/kg, average 143.3 mg/kg), the arsenic concentrations in Ca-Mg-HCO{sub 3} - water type are always lower than 10 {mu}g/l. Therefore, it does not seem to be probable that these deposits act as arsenic source, at least at the present physic-chemical conditions.(Author) 37 refs.

  15. Arsenic ototoxicity

    Institute of Scientific and Technical Information of China (English)

    Gulin Gokçen Kesici

    2016-01-01

    High levels of arsenic are found in many parts of the world and more than 100 million people may have been exposed to it. There is growing evidence to indicate that arsenic has a deleterious effect on the auditory system. This paper provides the general information of arsenic and its ototoxic effects.

  16. Potential of using arsenic-safe aquifers as sustainable drinking water sources in arsenic-affected areas of Bengal basin, India and Bangladesh

    Science.gov (United States)

    Bhattacharya, Prosun; Mukherjee, Abhijit; Biswas, Ashis; Hossain, Mohammed; von Brömssen, Mattias

    2016-04-01

    Naturally occurring arsenic (As) in Holocene aquifers in Bengal basin (India and Bangladesh) have undermined a long success of supplying the population with safe drinking water. Several studies have shown that many of the tested mitigation options have not been well accepted by the people. Instead, local drillers target presumed safe groundwater on the basis of the colour of the sediments. The overall objective of the study has thus been focused on assessing the potential for local drillers to target As safe groundwater. The specific objectives have been to validate the correlation between aquifer sediment colours and groundwater chemical composition, characterize aqueous and solid phase geochemistry and dynamics of As mobility and to assess the risk for cross-contamination of As between aquifers in areas of southeastern Bangladesh and West Bengal. Drillings to a depth of 60 m revealed two distinct hydrostratigraphic units, a strongly reducing aquifer unit with black to grey sediments overlying a patchy sequence of weathered and oxidised white, yellowish-grey to reddish-brown sediment. The aquifers are separated by an impervious clay unit. The reducing aquifer is characterized by high concentrations of dissolved As, DOC, Fe and PO43--tot. On the other hand, the off-white and red sediments contain relatively higher concentrations of Mn and SO42- and low As. Groundwater chemistry correlates well with the colours of the aquifer sediments. Geochemical investigations indicate that secondary mineral phases control dissolved concentrations of Mn, Fe and PO43--tot. Dissolved As is influenced by the amount of Hfo, pH and PO43--tot as a competing ion. Laboratory studies suggest that oxidised sediments have a higher capacity to absorb As. Monitoring of hydraulic heads and groundwater modelling illustrate a complex aquifer system with three aquifers to a depth of 250 m. Groundwater modelling studies illustrate two groundwater flowsystems: i) a deeper regional predominantly

  17. IMPACTS OF SOURCE TERM HETEROGENEITIES ON WATER PATHWAY DOSE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.; GUSKOV, A.; POSKAS, P.; RUPERTI, N.; HANUSIK, V.; ET AL.

    2004-09-15

    specific activities and small physical sizes and for which a solution has to be found in term of long-term disposal. Together with their casing and packaging, they are one form of heterogeneous waste; many other forms of waste with heterogeneous properties exist. They may arise in very small quantities and with very specific characteristics in the case of small producers, or in larger streams with standard characteristics in others. This wide variety of waste induces three main different levels of waste heterogeneity: (1) hot spot (e.g. disused sealed sources); (2) large item inside a package (e.g. metal components); and (3) very large items to be disposed of directly in the disposal unit (e.g. irradiated pipes, vessels). Safety assessments generally assume a certain level of waste homogeneity in most of the existing or proposed disposal facilities. There is a need to evaluate the appropriateness of such an assumption and the influence on the results of safety assessment. This need is especially acute in the case of sealed sources. There are many cases where are storage conditions are poor, or there is improper management leading to a radiological accident, some with significant or detrimental impacts. Disposal in a near surface disposal facility has been used in the past for some disused sealed sources. This option is currently in use for others sealed sources, or is being studied for the rest of them. The regulatory framework differs greatly between countries. In some countries, large quantities of disused sealed sources have been disposed of without any restriction, in others their disposal is forbidden by law. In any case, evaluation of the acceptability of disposal of disused sealed sources in near surface disposal facility is of utmost importance.

  18. Long-term outcome of acute promyelocytic leukemia treated with all-trans-retinoic acid, arsenic trioxide, and gemtuzumab.

    Science.gov (United States)

    Abaza, Yasmin; Kantarjian, Hagop; Garcia-Manero, Guillermo; Estey, Elihu; Borthakur, Gautam; Jabbour, Elias; Faderl, Stefan; O'Brien, Susan; Wierda, William; Pierce, Sherry; Brandt, Mark; McCue, Deborah; Luthra, Rajyalakshmi; Patel, Keyur; Kornblau, Steven; Kadia, Tapan; Daver, Naval; DiNardo, Courtney; Jain, Nitin; Verstovsek, Srdan; Ferrajoli, Alessandra; Andreeff, Michael; Konopleva, Marina; Estrov, Zeev; Foudray, Maria; McCue, David; Cortes, Jorge; Ravandi, Farhad

    2017-03-09

    The combination of all-trans-retinoic acid (ATRA) plus arsenic trioxide (ATO) has been shown to be superior to ATRA plus chemotherapy in the treatment of standard-risk patients with newly diagnosed acute promyelocytic leukemia (APL). A recent study demonstrated the efficacy of this regimen with added gemtuzumab ozogamicin (GO) in high-risk patients. We examined the long-term outcome of patients with newly diagnosed APL treated at our institution on 3 consecutive prospective clinical trials, using the combination of ATRA and ATO, with or without GO. For induction, all patients received ATRA (45 mg/m(2) daily) and ATO (0.15 mg/kg daily) with a dose of GO (9 mg/m(2) on day 1) added to high-risk patients (white blood cell count, >10 × 10(9)/L), as well as low-risk patients who experienced leukocytosis during induction. Once in complete remission, patients received 4 cycles of ATRA plus ATO consolidation. One hundred eighty-seven patients, including 54 with high-risk and 133 with low-risk disease, have been treated. The complete remission rate was 96% (52 of 54 in high-risk and 127 of 133 in low-risk patients). Induction mortality was 4%, with only 7 relapses. Among low-risk patients, 60 patients (45%) required either GO or idarubicin for leukocytosis. Median duration of follow-up was 47.6 months. The 5-year event-free, disease-free, and overall survival rates are 85%, 96%, and 88%, respectively. Late hematological relapses beyond 1 year occurred in 3 patients. Fourteen deaths occurred beyond 1 year; 12 were related to other causes. This study confirms the durability of responses with this regimen.

  19. Bioavailability links mode of action can improve the long-term field risk assessment for tilapia exposed to arsenic.

    Science.gov (United States)

    Tsai, Jeng-Wei; Chen, Wei-Yu; Ju, Yun-Ru; Liao, Chung-Min

    2009-05-01

    The objective of this paper was to develop a mechanistic-based framework to explicitly incorporate the factors controlling the bioavailability, toxicodynamics and mode of action to enhance predictive ability of arsenic (As) toxicity to protect the health of farmed tilapia Oreochromis mossambicus. We linked the biotic ligand model and damage assessment model to develop a toxicokinetic model for elucidating the site-specific temporal changes of As bioavailability and to characterize how the fish regulate the metal toxicity. We built a bioavailability-mode of action-based growth toxicity model by linking a bioenergetic growth model and damage assessment model to predict how the As affects on the tilapia growth in the entire life span in site-specific field ecosystems. Here we show that the proposed model well describes the water-chemistry-dependent toxicokinetics and toxicodynamics variations of As to tilapia. We selected two local tilapia farms with different water chemistries located at southwestern Taiwan coast region to implement the proposed algorithm to predict the risk of As exposure. Results indicate that the growth toxicity of O. mossambicus in Taihsi is more sensitive than that in Peimen. We found that the effect of ion competition on the As bioavailability and their ecotoxicological effects on tilapia are more obvious in Taihsi comparing with that in Peimen. We suggested that the proposed bioavailability- and mode of action-based framework can be used to capture the biological response and regulation of tilapia to As exposures. It is applicable for a site-specific and long-term ecotoxicological risk assessment.

  20. Long-Term Prospective Study of 6104 Survivors of Arsenic Poisoning During Infancy Due to Contaminated Milk Powder in 1955

    OpenAIRE

    Tanaka, Hideo; Tsukuma, Hideaki; Oshima, Akira

    2010-01-01

    Background In 1955, an outbreak of arsenic poisoning caused by ingestion of arsenic-contaminated dry milk occurred in western Japan. We assessed the excess mortality among Japanese who were poisoned during this episode as infants. Methods We identified and enrolled 6104 survivors (mean age at enrollment, 27.4 years) who had ingested contaminated milk when they were age 2 years or younger; they were followed until 2006 (mean duration of follow-up, 24.3 years). Death certificates of subjects wh...

  1. Management of the Arsenic Groundwater System Lagunera - MEXICO

    Science.gov (United States)

    Boochs, P. W.; Billib, M.; Aparicio, J.; Gutierrez, C.

    2007-05-01

    Arsenic in drinking water is considered one of the most important environmental causes of cancer mortality in the world. Groundwater resources of the Comarca Lagunera region (Northern Mexico), which represents the main source of drinking water for more than 2 million people in the area, show arsenic concentrations ranging from 5 to 750 micro g/l. Large areas have concentrations quite above the Mexican standard of 25 micro g/l for human use and consumption. The aquifer is overexploited and the groundwater levels at the central part of the aquifer are drawn down more than 100 m in less than 50 years. The drawdown provoked the dissolution and migration of the geogenic existing arsenic within the aquifer. The presence of arsenic has been related to several potential sources. It was found out, that the main source is geothermal activity, less mining and the use of arsenical pesticides. The process of the geneses of the arsenic pollution implicates, that the highest content is on the bottom of the aquifer. Data analysis showed, that arsenic concentration is correlated to the age of the groundwater. "Older" water has higher arsenic content than "younger" water and the oldest water can be found at the bottom of the aquifer. Before 1950 the groundwater level in the Comarca Lagunera was close to the surface and there were only dug and shallow wells with low groundwater abstraction. The water was pumped from the upper parts of the aquifer and because this was "young" water it had low arsenic content. Then after 1950 a lot of wells, mainly for irrigation, were built and in 2002 there were 2350 active wells with an abstraction of about 1088 Mio cbm/year. In consequence to this the groundwater level decreased extraordinary. More and more "older" water was pumped and the arsenic content increased. Furthermore at the beginning of 1960 the river Nazas was canalized and lined, so that the natural groundwater recharge by infiltration from the river was stopped. By this way, the

  2. Brines as Sources of Long-term Subsurface Contamination

    Science.gov (United States)

    Flowers, T. C.; Hunt, J. R.

    2004-12-01

    Concentrated salt solutions, i.e. brines, are source terms for environmental contaminants released into surface waters and groundwaters. Brines arise from both natural and industrial processes such as natural salt deposits, solid rocket fuel production, landfill leachates, nuclear fuel reprocessing, and acid rock drainage. Additionally, many of the in-situ remediation fluids that have been implemented at the pilot or the field scale are also classified as brines. While brines are miscible with water, mixing processes are slow in the subsurface and this constrains the dilution of contaminants present within brines and the delivery of remediation fluids to sites where reactions are needed. The mixing of brines during their vertical migration through aquifers is determined by aquifer permeability as well as differences in density and viscosity between the brine and the ambient groundwater. The stability criterion for brine displacement was predicted in 1952 by Hill and the resulting dispersion at the mixing front is quantified by a compilation of literature data and the acquisition of new experimental data. As brines sink through aquifers, they become emplaced in less accessible locations where mass transfer models predict that contaminants within brines are slowly released into flowing groundwater. For radioactive wastes and environmental contaminants with very low acceptable concentrations, groundwater quality can be impacted for decades. Field data from a cooling water disposal site suggest that a dense brine is likely still present as a source term 40 years after waste disposal was stopped. Overall, analysis of pollution sources, quantification of transport processes, generalization of laboratory data, and limited evaluation of field data indicate that brines represent long-term sources of groundwater contamination and that source control has not been seriously addressed.

  3. Paradigms and commonalities in atmospheric source term estimation methods

    Science.gov (United States)

    Bieringer, Paul E.; Young, George S.; Rodriguez, Luna M.; Annunzio, Andrew J.; Vandenberghe, Francois; Haupt, Sue Ellen

    2017-05-01

    Modeling the downwind hazard area resulting from the unknown release of an atmospheric contaminant requires estimation of the source characteristics of a localized source from concentration or dosage observations and use of this information to model the subsequent transport and dispersion of the contaminant. This source term estimation problem is mathematically challenging because airborne material concentration observations and wind data are typically sparse and the turbulent wind field chaotic. Methods for addressing this problem fall into three general categories: forward modeling, inverse modeling, and nonlinear optimization. Because numerous methods have been developed on various foundations, they often have a disparate nomenclature. This situation poses challenges to those facing a new source term estimation problem, particularly when selecting the best method for the problem at hand. There is, however, much commonality between many of these methods, especially within each category. Here we seek to address the difficulties encountered when selecting an STE method by providing a synthesis of the various methods that highlights commonalities, potential opportunities for component exchange, and lessons learned that can be applied across methods.

  4. Occurrence and possible sources of arsenic in seafloor sediments surrounding sea-disposed munitions and chemical agents near O´ahu, Hawai´i

    Science.gov (United States)

    Tomlinson, Michael S.; De Carlo, Eric Heinen

    2016-06-01

    The Department of Defense disposed of conventional and chemical munitions as well as bulk containers of chemical agents in US coastal waters including those surrounding the State of Hawai´i. The Hawai´i Undersea Military Munitions Assessment has been collecting biota, water, and sediment samples from two disposal areas south of the island of O´ahu in waters 500 to 600 m deep known to have received both conventional munitions and chemical agents (specifically sulfur mustard). Unlike a number of other sea-disposed munitions investigations which used grabs or corers lowered from surface vessels, we used manned submersibles to collect the samples. Using this approach, we were able to visually identify the munitions and precisely locate our samples in relation to the munitions on the seafloor. This paper focuses on the occurrence and possible sources of arsenic found in the sediments surrounding the disposed military munitions and chemical agents. Using nonparametric multivariate statistical techniques, we looked for patterns in the chemical data obtained from these sediment samples in order to determine the possible sources of the arsenic found in these sediments. The results of the ordination technique nonmetric multidimensional scaling indicate that the arsenic is associated with terrestrial sources and not munitions. This was not altogether surprising given that: (1) the chemical agents disposed of in this area supposedly did not contain arsenic, and (2) the disposal areas studied were under terrestrial influence or served as dredge spoil disposal sites. The sediment arsenic concentrations during this investigation ranged from <1.3 to 40 mg/kg-dry weight with the lower concentrations typically found around control sites and munitions (not located in dredge disposal areas) and the higher values found at dredge disposal sites (with or without munitions). During the course of our investigation we did, however, discover that mercury appears to be loosely associated

  5. Arsenic Contamination in Food-chain: Transfer of Arsenic into Food Materials through Groundwater Irrigation

    Science.gov (United States)

    Joardar, J.C.; Parvin, S.; Correll, Ray; Naidu, Ravi

    2006-01-01

    Arsenic contamination in groundwater in Bangladesh has become an additional concern vis-à-vis its use for irrigation purposes. Even if arsenic-safe drinking-water is assured, the question of irrigating soils with arsenic-laden groundwater will continue for years to come. Immediate attention should be given to assess the possibility of accumulating arsenic in soils through irrigation-water and its subsequent entry into the food-chain through various food crops and fodders. With this possibility in mind, arsenic content of 2,500 water, soil and vegetable samples from arsenic-affected and arsenic-unaffected areas were analyzed during 1999–2004. Other sources of foods and fodders were also analyzed. Irrigating a rice field with groundwater containing 0.55 mg/L of arsenic with a water requirement of 1,000 mm results in an estimated addition of 5.5 kg of arsenic per ha per annum. Concentration of arsenic as high as 80 mg per kg of soil was found in an area receiving arsenic-contaminated irrigation. A comparison of results from affected and unaffected areas revealed that some commonly-grown vegetables, which would usually be suitable as good sources of nourishment, accumulate substantially-elevated amounts of arsenic. For example, more than 150 mg/kg of arsenic has been found to be accumulated in arum (kochu) vegetable. Implications of arsenic ingested in vegetables and other food materials are discussed in the paper. PMID:17366772

  6. Effect of Vitamin E Supplementation on Hematological and Plasma Biochemical Parameters during Long Term Exposure of Arsenic in Goats

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Das

    2012-09-01

    Full Text Available The present investigation was designed to determine whether supplementation of different level of vitamin E for 12 months to arsenic exposed goats (50 ppm as sodium arsenite affords protection against the blood hemato-biochemical parameters caused by the metalloid. A total of 24 crossbred (Alpine×Beetal lactating goats were assigned randomly into 4 equal groups (control, T1, T2 and T3 of 6 in each, on the basis of average body weight (36.10±0.11 kg and milk yield (1.61±0.04 kg/d. The animals in T1, T2 and T3 were given 50 ppm arsenic, while in T2 and T3, additionally; vitamin E at the rate of 100 IU and 150 IU/kg dry matter (DM respectively was additionally supplemented for the period of 12 months. Hemoglobin (Hb, total leukocyte (TLC and blood lymphocyte % were decreased (p0.05 but creatinine level was periodically increased in all As supplemented groups and vitamin E supplementation did not produce any protective effect. It can be concluded that arsenic exposure resulted in varying degree of changes in hemato-biochemical parameters and activities of antioxidant enzymes in goats but concomitant treatment with Vitamin E is partially helpful in reducing the burden of arsenic induced effect.

  7. Arsenic mass balance in a paper mill and impact of the arsenic release from the WWTP effluent on the Moselle River.

    Science.gov (United States)

    Michon, C; Pons, M-N; Bauda, P; Poirot, H; Potier, O

    2011-01-01

    Rivers used for drinking water production might be subject to anthropogenic pollution discharge upstream of the intake point. This problem was investigated in the case of the Moselle River, used for water production in Nancy (350,000 inhabitants) and which might be impacted by industrial activities 60 km upstream. The arsenic flux of a pulp and paper mill discharging in the Moselle River at this location has been more specifically investigated. The main sources of arsenic in that mill seemed to be the recovered papers and the gravel pit water used as feed water. The arsenic input related to wood and bark was limited. The main arsenic outputs from the plant were the paper produced on site and the deinking sludge. The arsenic concentration in the effluent of the wastewater treatment plant (WWTP) was not correlated to the one in the gravel pit water, but may depend on the operating conditions of the WWTP or the changes in processes of the mill. The impact of this anthropogenic source of arsenic on the Moselle River was slightly larger in summer, when the flowrate was lower. Globally the impact of the paper mill on the Moselle River water quality was limited in terms of arsenic.

  8. Long-term variability of extragalactic radio sources in the Planck Early Release Compact Source Catalogue

    CERN Document Server

    Chen, X; Lopez-Caniego, M; Dickinson, C; Pearson, T J; Fuhrmann, L; Krichbaum, T P; Partridge, B

    2013-01-01

    Combining measurements taken using the Wilkinson Microwave Anisotropy Probe (WMAP) from 2001 to 2008 with measurements taken using Planck from 2009 to 2010, we investigate the long-term flux density variability of extragalactic radio sources selected from the Planck Early Release Compact Source Catalogue. The single-year, single-frequency WMAP maps are used to estimate yearly-averaged flux densities of the sources in the four WMAP bands: Ka (33 GHz), Q (41 GHz), V (61 GHz), and W (94 GHz). We identify 82, 67, 32, and 15 sources respectively as variable at greater than 99% confidence level in these four bands. The amplitudes of variation are comparable between bands, and are not correlated with either the flux densities or the spectral indices of the sources. The number counts of WMAP Ka-band sources are stable from year to year despite the fluctuation caused by individual source variability. Most of our sources show strong correlation in variability between bands. Almost all the sources that show variability ...

  9. Methodology for a bounding estimate of activation source-term.

    Science.gov (United States)

    Culp, Todd

    2013-02-01

    Sandia National Laboratories' Z-Machine is the world's most powerful electrical device, and experiments have been conducted that make it the world's most powerful radiation source. Because Z-Machine is used for research, an assortment of materials can be placed into the machine; these materials can be subjected to a range of nuclear reactions, producing an assortment of activation products. A methodology was developed to provide a systematic approach to evaluate different materials to be introduced into the machine as wire arrays. This methodology is based on experiment specific characteristics, physical characteristics of specific radionuclides, and experience with Z-Machine. This provides a starting point for bounding calculations of radionuclide source-term that can be used for work planning, development of work controls, and evaluating materials for introduction into the machine.

  10. Trace metal source terms in carbon sequestration environments.

    Science.gov (United States)

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2013-01-02

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising; however, possible CO(2) or CO(2)-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define a range of concentrations that can be used as the trace element source term for reservoirs and leakage pathways in risk simulations. Storage source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from cements and sandstones, shales, carbonates, evaporites, and basalts from the Frio, In Salah, Illinois Basin, Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands, and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution was tracked by measuring solution concentrations over time under conditions (e.g., pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for maximum contaminant levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments because of the presence of CO(2). Results indicate that Cr and Pb released from sandstone reservoir and shale cap rocks exceed the MCLs by an order of magnitude, while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the trace element source term for reservoirs and leakage pathways in risk simulations to further evaluate the impact of leakage on groundwater quality.

  11. Trace Metal Source Terms in Carbon Sequestration Environments

    Energy Technology Data Exchange (ETDEWEB)

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2012-02-05

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising, however, possible CO₂ or CO₂-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define trace metal source terms from the reaction of supercritical CO₂, storage reservoir brines, reservoir and cap rocks. Storage reservoir source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from sandstones, shales, carbonates, evaporites, basalts and cements from the Frio, In Salah, Illinois Basin – Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution is tracked by measuring solution concentrations over time under conditions (e.g. pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for Maximum Contaminant Levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments due to the presence of CO₂. Results indicate that Cr and Pb released from sandstone reservoir and shale cap rock exceed the MCLs by an order of magnitude while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the reservoir and caprock source term to further evaluate the impact of leakage on groundwater quality.

  12. An establishment of MELCOR code to generate source terms for off site consequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. H.; Han, S.; Ahn, K. I. [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Since the Fukushima accident, an effective approach to a source term analysis for off site consequence analyses has been needed. The MELCOR code has the capability to assess the source term characteristics for this kind of demand. A comprehensive effort is required to use the MELCOR code for a source term analysis effectively. For this purpose, the following works are required: - Review and assess the MELCOR model relevant to source term characterization - Generate input files for source term analysis - Utilize the source term parameters This paper shows an effort to establish the MELCOR code to generate source terms for an off site consequence analysis.

  13. Development of alternate methods of determining integrated SMR source terms

    Energy Technology Data Exchange (ETDEWEB)

    Barry, Kenneth [Electric Power Research Inst. (EPRI), Charlotte, NC (United States)

    2014-06-10

    The Nuclear Energy Institute (NEI) Small Modular Reactor (SMR) Licensing Task Force (TF) has been evaluating licensing issues unique and important to iPWRs, ranking these issues, and developing NEI position papers for submittal to the U.S. Nuclear Regulatory Commission (NRC) during the past three years. Papers have been developed and submitted to the NRC in a range of areas including: Price-Anderson Act, NRC annual fees, security, modularity, and staffing. In December, 2012, NEI completed a draft position paper on SMR source terms and participated in an NRC public meeting presenting a summary of this paper, which was subsequently submitted to the NRC. One important conclusion of the source term paper was the evaluation and selection of high importance areas where additional research would have a significant impact on source terms. The highest ranked research area was iPWR containment aerosol natural deposition. The NRC accepts the use of existing aerosol deposition correlations in Regulatory Guide 1.183, but these were developed for large light water reactor (LWR) containments. Application of these correlations to an iPWR design has resulted in greater than a ten-fold reduction of containment airborne aerosol inventory as compared to large LWRs. Development and experimental justification of containment aerosol natural deposition correlations specifically for the unique iPWR containments is expected to result in a large reduction of design basis and beyond-design-basis accident source terms with concomitantly smaller dose to workers and the public. Therefore, NRC acceptance of iPWR containment aerosol natural deposition correlations will directly support the industry’s goal of reducing the Emergency Planning Zone (EPZ) for SMRs. Based on the results in this work, it is clear that thermophoresis is relatively unimportant for iPWRs. Gravitational settling is well understood, and may be the dominant process for a dry environment. Diffusiophoresis and enhanced

  14. Fourth order wave equations with nonlinear strain and source terms

    Science.gov (United States)

    Liu, Yacheng; Xu, Runzhang

    2007-07-01

    In this paper we study the initial boundary value problem for fourth order wave equations with nonlinear strain and source terms. First we introduce a family of potential wells and prove the invariance of some sets and vacuum isolating of solutions. Then we obtain a threshold result of global existence and nonexistence. Finally we discuss the global existence of solutions for the problem with critical initial condition I(u0)[greater-or-equal, slanted]0, E(0)=d. So the Esquivel-Avila's results are generalized and improved.

  15. Quasilinear equations with source terms on Carnot groups

    CERN Document Server

    Phuc, Nguyen Cong

    2012-01-01

    In this paper we give necessary and sufficient conditions for the existence of solutions to quasilinear equations of Lane--Emden type with measure data on a Carnot group $\\mathbb G$ of arbitrary step. The quasilinear part involves operators of the $p$-Laplacian type $\\Delta_{\\mathbb G,\\,p}\\,$, $1terms of nonlinear potentials of Th. Wolff's type. As a consequence, we characterize completely removable singularities, and prove a Liouville type theorem for supersolutions of quasilinear equations with source terms which has been known only for equations involving the sub-Laplacian ($p=2$) on the Heisenberg group.

  16. Arsenic health risk assessment in drinking water and source apportionment using multivariate statistical techniques in Kohistan region, northern Pakistan.

    Science.gov (United States)

    Muhammad, Said; Tahir Shah, M; Khan, Sardar

    2010-10-01

    The present study was conducted in Kohistan region, where mafic and ultramafic rocks (Kohistan island arc and Indus suture zone) and metasedimentary rocks (Indian plate) are exposed. Water samples were collected from the springs, streams and Indus river and analyzed for physical parameters, anions, cations and arsenic (As(3+), As(5+) and arsenic total). The water quality in Kohistan region was evaluated by comparing the physio-chemical parameters with permissible limits set by Pakistan environmental protection agency and world health organization. Most of the studied parameters were found within their respective permissible limits. However in some samples, the iron and arsenic concentrations exceeded their permissible limits. For health risk assessment of arsenic, the average daily dose, hazards quotient (HQ) and cancer risk were calculated by using statistical formulas. The values of HQ were found >1 in the samples collected from Jabba, Dubair, while HQ values were samples. This level of contamination should have low chronic risk and medium cancer risk when compared with US EPA guidelines. Furthermore, the inter-dependence of physio-chemical parameters and pollution load was also calculated by using multivariate statistical techniques like one-way ANOVA, correlation analysis, regression analysis, cluster analysis and principle component analysis.

  17. Chronic arsenic poisoning from burning high-arsenic-containing coal in Guizhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.; Zheng, B.S.; Aposhian, H.V.; Zhou, Y.S.; Chen, M.L.; Zhang, A.H.; Waalkes, M.P. [NIEHS, Research Triangle Park, NC (USA)

    2002-07-01

    Arsenic is an environmental hazard and the reduction of drinking water arsenic levels is under consideration. People are exposed to arsenic not only through drinking water but also through arsenic-contaminated air and food. Here the health effects of arsenic exposure from burning high arsenic-containing coal in Guizhou, China was investigated. Coal is burned inside the home in open pits for daily cooking and crop drying, producing a high concentration of arsenic in indoor air. Arsenic in the air coats and permeates food being dried producing high concentrations in food; however, arsenic concentrations in the drinking water are in the normal range. The estimated sources of total arsenic exposure in this area are from arsenic-contaminated food (50-80%), air (10-20%), water (1-5%), and direct contact in coal-mining workers (1%). At least 3,000 patients with arsenic poisoning were found in the Southwest Prefecture of Guizhou, and approximately 200,000 people are at risk for such over exposures. Skin lesions are common, including keratosis of the hands and feet, pigmentation on the trunk, skin ulceration, and skin cancers. Toxicities to internal organs, including lung dysfunction, neuropathy, and nephrotoxicity, are clinically evident. The prevalence of hepatomegaly was 20%, and cirrhosis, ascites, and liver cancer are the most serious outcomes of arsenic poisoning. The Chinese government and international organizations are attempting to improve the house conditions and the coal source, and thereby protect human health in this area.

  18. Effect of Vitamin E Supplementation on Hematological and Plasma Biochemical Parameters during Long Term Exposure of Arsenic in Goats.

    Science.gov (United States)

    Das, Tapan Kumar; Mani, Veena; Kaur, Harjit; Kewalramani, Neelam; Agarwal, Anjali

    2012-09-01

    The present investigation was designed to determine whether supplementation of different level of vitamin E for 12 months to arsenic exposed goats (50 ppm as sodium arsenite) affords protection against the blood hemato-biochemical parameters caused by the metalloid. A total of 24 crossbred (Alpine×Beetal) lactating goats were assigned randomly into 4 equal groups (control, T1, T2 and T3) of 6 in each, on the basis of average body weight (36.10±0.11 kg) and milk yield (1.61±0.04 kg/d). The animals in T1, T2 and T3 were given 50 ppm arsenic, while in T2 and T3, additionally; vitamin E at the rate of 100 IU and 150 IU/kg dry matter (DM) respectively was additionally supplemented for the period of 12 months. Hemoglobin (Hb), total leukocyte (TLC) and blood lymphocyte % were decreased (parsenic fed groups and vitamin E supplementation in the experimental group showed a protective potential. Significant increases (parsenic supplemented groups were recorded, however vitamin E supplementation at higher doses showed a protective effect (p0.05) but creatinine level was periodically increased in all As supplemented groups and vitamin E supplementation did not produce any protective effect. It can be concluded that arsenic exposure resulted in varying degree of changes in hemato-biochemical parameters and activities of antioxidant enzymes in goats but concomitant treatment with Vitamin E is partially helpful in reducing the burden of arsenic induced effect.

  19. A cultural practice of drinking realgar wine leading to elevated urinary arsenic and its potential health risk.

    Science.gov (United States)

    Zhang, Ying-Nan; Sun, Guo-Xin; Huang, Qing; Williams, Paul N; Zhu, Yong-Guan

    2011-07-01

    Toasting friends and family with realgar wines and painting children's foreheads and limbs with the leftover realgar/alcohol slurries is an important customary ritual during the Dragon Boat Festival (DBF); a Chinese national holiday and ancient feast day celebrated throughout Asia. Realgar is an arsenic sulfide mineral, and source of highly toxic inorganic arsenic. Despite the long history of realgar use during the DBF, associated risk to human health by arsenic ingestion or percutaneous adsorption is unknown. To address this urine samples were collected from a cohort of volunteers who were partaking in the DBF festivities. The total concentration of arsenic in the wine consumed was 70 mg L⁻¹ with all the arsenic found to be inorganic. Total arsenic concentrations in adult urine reached a maximum of ca. 550 μg L⁻¹ (mean 220.2 μg L⁻¹) after 16 h post-ingestion of realgar wine, while face painting caused arsenic levels in children's urine to soar to 100 μg L⁻¹ (mean 85.3 μg L⁻¹) 40 h after the initial paint application. The average concentration of inorganic arsenic in the urine of realgar wine drinkers on average doubled 16 h after drinking, although this was not permanent and levels subsided after 28 h. As would be expected in young children, the proportions of organic arsenic in the urine remained high throughout the 88-h monitoring period. However, even when arsenic concentrations in the urine peaked at 40 h after paint application, concentrations in the urine only declined slightly thereafter, suggesting pronounced longer term dermal accumulation and penetration of arsenic. Drinking wines blended with realgar or using realgar based paints on children does result in the significant absorption of arsenic and therefore presents a potentially serious and currently unquantified health risk.

  20. Arsenic and drinking water. Part 1. A review of the source, distribution and behaviour of arsenic in the environment; Arsen und Trinkwasser. Teil 1. Ein Ueberblick ueber Vorkommen, Verteilung und Verhalten von Arsen in der Umwelt

    Energy Technology Data Exchange (ETDEWEB)

    Oberacker, F.; Maier, D. [Heinrich-Sontheimer-Lab., DVGW-Technologiezentrum Wasser, Karlsruhe (Germany); Maier, M. [Stadtwerke Karlsruhe GmbH, Karlsruhe (Germany)

    2002-11-01

    Arsenic is ubiquituously distributed in our environment and is subject to continuous bio-geochemical cycling. Besides the acute toxicity of arsenic its chronic effects are of special importance. The permanent uptake with drinking water for example might cause cancer. Today, arsenic compounds hardly serve as pesticides anymore, although chromated copper arsenate is still used to preserve wood. Furthermore, arsenic is used in the alloy, glass and semiconductor industry. The main part of the earths' arsenic resources are bound to sulfur in the lithosphere. By means of rock weathering and volcanism it is transferred into pedo-, hydro- and atmosphere, where it is mainly bound to oxygen. Microorganisms are able to methylate the arsenic, whereby gaseous arsenic compounds are carried into the atmosphere. Also, it is released from the lithosphere through anthropogenic mining activities, although only for a small part of the released amount useful applications exist. The arsenic behaviour in natural waters is closely related to sulfur on the one hand and to iron oxides on the other. Under strongly reducing conditions the arsenic is precipitated as sulfide, while under oxidising conditions it is adsorbed to the surfaces of iron oxides. Therefore, under aerobic conditions the arsenic concentrations of aqueous solutions are controlled by these adsorption processes rather than by the solubility of solid arsenic phases. Manganese oxides also play an important role as they are able to rapidly oxidise As(III) to As(V). These processes of release and fixation of arsenic in the nature must be studied carefully, because they are applied for arsenic elimination during drinking water production as well. (orig.)

  1. Arsenic pesticides and environmental pollution: exposure, poisoning, hazards and recommendations.

    Science.gov (United States)

    El-Bahnasawy, Mamdouh M; Mohammad, Amina El-Hosini; Morsy, Tosson A

    2013-08-01

    Arsenic is a metalloid element. Acute high-dose exposure to arsenic can cause severe systemic toxicity and death. Lower dose chronic arsenic exposure can result in subacute toxicity that can include peripheral sensorimotor neuropathy, skin eruptions, and hepatotoxicity. Long-term effects of arsenic exposure include an in Due to the physiologic effects of the arsenic on all body systems, thus, chronic arsenic-poisoned patient is a major nursing challenge. The critical care nurse provides valuable assessment and interventions that prevent major multisystem complications from arsenic toxicity.

  2. A comparison of world-wide uses of severe reactor accident source terms

    Energy Technology Data Exchange (ETDEWEB)

    Ang, M.L. [NNC Ltd., Knutsford (United Kingdom); Frid, W. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Kersting, E.J.; Friederichs, H.G. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Germany); Lee, R.Y. [Nuclear Regulatory Commission, Washington, DC (United States); Meyer-Heine, A. [CEA Centre d`Etudes de Cadarache, Saint Paul Lez Durance (France); Powers, D.A. [Sandia National Labs., Albuquerque, NM (United States); Soda, K. [Japan Atomic Energy Research Inst., Tokyo (Japan); Sweet, D. [AEA Technology, Winfrith (United Kingdom)

    1994-09-01

    The definitions of source terms to reactor containments and source terms to the environment are discussed. A comparison is made between the TID-14844 example source term and the alternative source term described in NUREG-1465. Comparisons of these source terms to the containments and those used in France, Germany, Japan, Sweden, and the United Kingdom are made. Source terms to the environment calculated in NUREG-1500 and WASH-1400 are discussed. Again, these source terms are compared to those now being used in France, Germany, Japan, Sweden, and the United Kingdom. It is concluded that source terms to the containment suggested in NUREG-1465 are not greatly more conservative than those used in other countries. Technical bases for the source terms are similar. The regulatory use of the current understanding of radionuclide behavior varies among countries.

  3. Estimating Source Terms for Diverse Spent Nuclear Fuel Types

    Energy Technology Data Exchange (ETDEWEB)

    Brett Carlsen; Layne Pincock

    2004-11-01

    The U.S. Department of Energy (DOE) National Spent Nuclear Fuel Program is responsible for developing a defensible methodology for determining the radionuclide inventory for the DOE spent nuclear fuel (SNF) to be dispositioned at the proposed Monitored Geologic Repository at the Yucca Mountain Site. SNF owned by DOE includes diverse fuels from various experimental, research, and production reactors. These fuels currently reside at several DOE sites, universities, and foreign research reactor sites. Safe storage, transportation, and ultimate disposal of these fuels will require radiological source terms as inputs to safety analyses that support design and licensing of the necessary equipment and facilities. This paper summarizes the methodology developed for estimating radionuclide inventories associated with DOE-owned SNF. The results will support development of design and administrative controls to manage radiological risks and may later be used to demonstrate conformance with repository acceptance criteria.

  4. Tank waste source term inventory validation. Volume 1. Letter report

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.; Gaddis, L.A.; Johnson, E.D.

    1995-04-28

    The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun data base, Wastren (Van Vleet) data base, TRAC and HTCE inventories. This document is Volume I of the Letter Report entitled Tank Waste Source Term Inventory Validation.

  5. Implementation of the Arsenic Biosand Filter in Nepal

    Science.gov (United States)

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

    2004-05-01

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

  6. A Phytoremediation Strategy for Arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

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

  7. 5.0. Depletion, activation, and spent fuel source terms

    Energy Technology Data Exchange (ETDEWEB)

    Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    SCALE’s general depletion, activation, and spent fuel source terms analysis capabilities are enabled through a family of modules related to the main ORIGEN depletion/irradiation/decay solver. The nuclide tracking in ORIGEN is based on the principle of explicitly modeling all available nuclides and transitions in the current fundamental nuclear data for decay and neutron-induced transmutation and relies on fundamental cross section and decay data in ENDF/B VII. Cross section data for materials and reaction processes not available in ENDF/B-VII are obtained from the JEFF-3.0/A special purpose European activation library containing 774 materials and 23 reaction channels with 12,617 neutron-induced reactions below 20 MeV. Resonance cross section corrections in the resolved and unresolved range are performed using a continuous-energy treatment by data modules in SCALE. All nuclear decay data, fission product yields, and gamma-ray emission data are developed from ENDF/B-VII.1 evaluations. Decay data include all ground and metastable state nuclides with half-lives greater than 1 millisecond. Using these data sources, ORIGEN currently tracks 174 actinides, 1149 fission products, and 974 activation products. The purpose of this chapter is to describe the stand-alone capabilities and underlying methodology of ORIGEN—as opposed to the integrated depletion capability it provides in all coupled neutron transport/depletion sequences in SCALE, as described in other chapters.

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

    Science.gov (United States)

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

    2015-06-01

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

  9. Linking Microbial Activity with Arsenic Fate during Cow Dung Disposal of Arsenic-Bearing Wastes

    Science.gov (United States)

    Clancy, T. M.; Reddy, R.; Tan, J.; Hayes, K. F.; Raskin, L.

    2014-12-01

    To address widespread arsenic contamination of drinking water sources numerous technologies have been developed to remove arsenic. All technologies result in the production of an arsenic-bearing waste that must be evaluated and disposed in a manner to limit the potential for environmental release and human exposure. One disposal option that is commonly recommended for areas without access to landfills is the mixing of arsenic-bearing wastes with cow dung. These recommendations are made based on the ability of microorganisms to create volatile arsenic species (including mono-, di-, and tri-methylarsine gases) to be diluted in the atmosphere. However, most studies of environmental microbial communities have found only a small fraction (cow dung and arsenic-bearing wastes produced during drinking water treatment in West Bengal, India. Arsenic in gaseous, aqueous, and solid phases was measured. Consistent with previous reports, less than 0.02% of the total arsenic present was volatilized. A much higher amount (~5%) of the total arsenic was mobilized into the liquid phase. Through the application of molecular tools, including 16S rRNA sequencing and quantification of gene transcripts involved in methanogenesis, this study links microbial community activity with arsenic fate in potential disposal environments. These results illustrate that disposal of arsenic-bearing wastes by mixing with cow dung does not achieve its end goal of promoting arsenic volatilization but rather appears to increase arsenic mobilization in the aqueous phase, raising concerns with this approach.

  10. Chronic arsenic poisoning.

    Science.gov (United States)

    Hall, Alan H

    2002-03-10

    Symptomatic arsenic poisoning is not often seen in occupational exposure settings. Attempted homicide and deliberate long-term poisoning have resulted in chronic toxicity. Skin pigmentation changes, palmar and plantar hyperkeratoses, gastrointestinal symptoms, anemia, and liver disease are common. Noncirrhotic portal hypertension with bleeding esophageal varices, splenomegaly, and hypersplenism may occur. A metallic taste, gastrointestinal disturbances, and Mee's lines may be seen. Bone marrow depression is common. 'Blackfoot disease' has been associated with arsenic-contaminated drinking water in Taiwan; Raynaud's phenomenon and acrocyanosis also may occur. Large numbers of persons in areas of India, Pakistan, and several other countries have been chronically poisoned from naturally occurring arsenic in ground water. Toxic delirium and encephalopathy can be present. CCA-treated wood (chromated copper arsenate) is not a health risk unless burned in fireplaces or woodstoves. Peripheral neuropathy may also occur. Workplace exposure or chronic ingestion of arsenic-contaminated water or arsenical medications is associated with development of skin, lung, and other cancers. Treatment may incklude the use of chelating agents such as dimercaprol (BAL), dimercaptosuccinic acid (DMSA), and dimercaptopanesulfonic acid (DMPS).

  11. High exposure to inorganic arsenic by food: the need for risk reduction.

    Science.gov (United States)

    Gundert-Remy, Ursula; Damm, Georg; Foth, Heidi; Freyberger, Alexius; Gebel, Thomas; Golka, Klaus; Röhl, Claudia; Schupp, Thomas; Wollin, Klaus-Michael; Hengstler, Jan Georg

    2015-12-01

    Arsenic is a human carcinogen that occurs ubiquitously in soil and water. Based on epidemiological studies, a benchmark dose (lower/higher bound estimate) between 0.3 and 8 μg/kg bw/day was estimated to cause a 1 % increased risk of lung, skin and bladder cancer. A recently published study by EFSA on dietary exposure to inorganic arsenic in the European population reported 95th percentiles (lower bound min to upper bound max) for different age groups in the same range as the benchmark dose. For toddlers, a highly exposed group, the highest values ranged between 0.61 and 2.09 µg arsenic/kg bw/day. For all other age classes, the margin of exposure is also small. This scenario calls for regulatory action to reduce arsenic exposure. One priority measure should be to reduce arsenic in food categories that contribute most to exposure. In the EFSA study the food categories 'milk and dairy products,' 'drinking water' and 'food for infants' represent major sources of inorganic arsenic for infants and also rice is an important source. Long-term strategies are required to reduce inorganic arsenic in these food groups. The reduced consumption of rice and rice products which has been recommended may be helpful for a minority of individuals consuming unusually high amounts of rice. However, it is only of limited value for the general European population, because the food categories 'grain-based processed products (non rice-based)' or 'milk and dairy products' contribute more to the exposure with inorganic arsenic than the food category 'rice.' A balanced regulatory activity focusing on the most relevant food categories is required. In conclusion, exposure to inorganic arsenic represents a risk to the health of the European population, particularly to young children. Regulatory measures to reduce exposure are urgently required.

  12. Suicide behaviour and arsenic levels in drinking water: a possible association?: A review of the literature about the effects of arsenic contamination in drinking water on suicides.

    Science.gov (United States)

    Troiano, Gianmarco; Mercurio, Isabella; Melai, Paola; Nante, Nicola; Lancia, Massimo; Bacci, Mauro

    2017-01-01

    A considerable part of the global population is exposed to arsenic-contaminated drinking water which is the main source of inorganic arsenic(As) exposure in humans. Arsenic exposure interferes with the action of enzymes, essential cations, and transcriptional events in cells throughout the body, and a multitude of multisystemic non-cancer effects might ensue. The aim of our review was to evaluate the effects of arsenic contamination in drinking water on suicides rates. A systematic literature search (English written literature) was conducted in electronic databases MEDLINE, SCOPUS. Evidences dating from 1999 till 2016 have been collected. A manual search of reference lists of included studies and review articles was successively performed. All references of the retrieved studies were also reviewed to avoid missing relevant publications. The key search terms included: "arsenic AND water AND suicide". The literature search yielded 13 publications, but we identified 2 manuscripts available for this systematic review. The 2 studies included in the review, were published in 2015 and in 2017 and settled in Italy and Hungary. The levels of arsenic in the waters ranged from 0.016 μg/l to >50 μg/l. The findings of the two studies are conflicting, in fact Pompili et al. reported an apparently beneficial effect of arsenic on suicides rates, with an inverse correlation of arsenic concentration and local suicide rates, in contrast to a positive correlation with natural-cause mortality rates. Our review led to conflicting results, so the diatribe about the real effects of arsenic intake of suicidal behaviors is still open. Therefore, we encourage other colleagues to conduct further studies in other locations in order to have more reliable results.

  13. Acceptance and use of eight arsenic-safe drinking water options in Bangladesh.

    Science.gov (United States)

    Inauen, Jennifer; Hossain, Mohammad Mojahidul; Johnston, Richard B; Mosler, Hans-Joachim

    2013-01-01

    Arsenic contamination of drinking water is a serious public health threat. In Bangladesh, eight major safe water options provide an alternative to contaminated shallow tubewells: piped water supply, deep tubewells, pond sand filters, community arsenic-removal, household arsenic removal, dug wells, well-sharing, and rainwater harvesting. However, it is uncertain how well these options are accepted and used by the at-risk population. Based on the RANAS model (risk, attitudes, norms, ability, and self-regulation) this study aimed to identify the acceptance and use of available safe water options. Cross-sectional face-to-face interviews were used to survey 1,268 households in Bangladesh in November 2009 (n = 872), and December 2010 (n = 396). The questionnaire assessed water consumption, acceptance factors from the RANAS model, and socioeconomic factors. Although all respondents had access to at least one arsenic-safe drinking water option, only 62.1% of participants were currently using these alternatives. The most regularly used options were household arsenic removal filters (92.9%) and piped water supply (85.6%). However, the former result may be positively biased due to high refusal rates of household filter owners. The least used option was household rainwater harvesting (36.6%). Those who reported not using an arsenic-safe source differed in terms of numerous acceptance factors from those who reported using arsenic-safe sources: non-users were characterized by greater vulnerability; showed less preference for the taste and temperature of alternative sources; found collecting safe water quite time-consuming; had lower levels of social norms, self-efficacy, and coping planning; and demonstrated lower levels of commitment to collecting safe water. Acceptance was particularly high for piped water supplies and deep tubewells, whereas dug wells and well-sharing were the least accepted sources. Intervention strategies were derived from the results in order to

  14. Removal processes for arsenic in constructed wetlands.

    Science.gov (United States)

    Lizama A, Katherine; Fletcher, Tim D; Sun, Guangzhi

    2011-08-01

    Arsenic pollution in aquatic environments is a worldwide concern due to its toxicity and chronic effects on human health. This concern has generated increasing interest in the use of different treatment technologies to remove arsenic from contaminated water. Constructed wetlands are a cost-effective natural system successfully used for removing various pollutants, and they have shown capability for removing arsenic. This paper reviews current understanding of the removal processes for arsenic, discusses implications for treatment wetlands, and identifies critical knowledge gaps and areas worthy of future research. The reactivity of arsenic means that different arsenic species may be found in wetlands, influenced by vegetation, supporting medium and microorganisms. Despite the fact that sorption, precipitation and coprecipitation are the principal processes responsible for the removal of arsenic, bacteria can mediate these processes and can play a significant role under favourable environmental conditions. The most important factors affecting the speciation of arsenic are pH, alkalinity, temperature, dissolved oxygen, the presence of other chemical species--iron, sulphur, phosphate--,a source of carbon, and the wetland substrate. Studies of the microbial communities and the speciation of arsenic in the solid phase using advanced techniques could provide further insights on the removal of arsenic. Limited data and understanding of the interaction of the different processes involved in the removal of arsenic explain the rudimentary guidelines available for the design of wetlands systems. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Unusual presentation of arsenic poisoning in a case of celiac disease.

    Science.gov (United States)

    Hasanato, Rana M; Almomen, AbdulKareem M

    2015-01-01

    Arsenic poisoning may occur from sources other than drinking water such as rice, seafood, or insecticides. Symptoms and signs can be insidious, non-specific, atypical, and easily overlooked. We present a 39-year-old woman with celiac disease who was on gluten-free diet for 8 years and presented with diarrhea, headache, insomnia, loss of appetite, abnormal taste, and impaired short-term memory and concentration, but with no skin lesions. Arsenic concentration in her 24-hour urine was 682.77 micro g/g creatinine (normal arsenic poisoning was rice, as drink.ing contaminated ground water is not known in Saudi Arabia and she had not taken seafood. Therefore, arsenic poisoning should be suspected based on the meticulous medical history in cases of patients with celiac disease whose main food is rice and who present with unusual symptoms.

  16. Approximate solution for SPP with discontinuous source term

    Directory of Open Access Journals (Sweden)

    Adžić Nevenka

    2004-01-01

    Full Text Available In this paper we shall consider self-adjoint singularly perturbed problem described by the ordinary differential equation of second order with small parameter multiplying the highest derivative and discontinuous source term, and the appropriate boundary conditions, which describes steady state of certain flow problems. The solution displays both boundary layers and an interior layer. The domain decomposition will be performed determining layer subintervals which are adapted to polynomial approximation. The division points for the interior layer are determined by the procedure similar to the one for boundary layers using appropriate resemblance function. The solution out of boundary layer is approximated by the solution of the reduced problem, and the layer solutions is approximated by truncated orthogonal series giving a smooth approximate solution upon the entire interval. The coefficients of the truncated series are evaluated using pseudospectral technique. The rate of convergence is examined and the order-of-magnitude of the error is given, using the principle of inverse monotonicity and the behavior of the pseudospectral approximations. Numerical example is included and it shows the high accuracy of the presented method. .

  17. Source term analysis for a nuclear submarine accident

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.J.; Hugron, J.J.M.R. [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada)

    1999-07-01

    A source term analysis has been conducted to determine the activity release into the environment as a result of a large-break loss-of-coolant accident aboard a visiting nuclear-powered submarine to a Canadian port. This best-estimate analysis considers the fractional release from the core, and fission product transport in the primary heat transport system, primary containment (i.e. reactor compartment) and submarine hull. Physical removal mechanisms such as vapour and aerosol deposition are treated in the calculation. Since a thermalhydraulic analysis indicated that the integrity of the reactor compartment is maintained, release from the reactor compartment will only occur by leakage; however, it is conservatively assumed that the secondary containment is not isolated for a 24-h period where release occurs through an open hatch in the submarine hull. Consequently, during this period, the activity release into the atmosphere is estimated as 4.6 TBq, leading to a maximum individual dose equivalent of 0.5 mSv at 800 metres from the berthing location. This activity release is comparable to that obtained in the BEREX TSA study (for a similar accident scenario) but is four orders of magnitude less than that reported in the earlier Davis study where, unrealistically, no credit had been taken for the containment system or for any physical removal processes. (author)

  18. A parameter model for dredge plume sediment source terms

    Science.gov (United States)

    Decrop, Boudewijn; De Mulder, Tom; Toorman, Erik; Sas, Marc

    2017-01-01

    The presented model allows for fast simulations of the near-field behaviour of overflow dredging plumes. Overflow dredging plumes occur when dredging vessels employ a dropshaft release system to discharge the excess sea water, which is pumped into the trailing suction hopper dredger (TSHD) along with the dredged sediments. The fine sediment fraction in the loaded water-sediment mixture does not fully settle before it reaches the overflow shaft. By consequence, the released water contains a fine sediment fraction of time-varying concentration. The sediment grain size is in the range of clays, silt and fine sand; the sediment concentration varies roughly between 10 and 200 g/l in most cases, peaking at even higher value with short duration. In order to assess the environmental impact of the increased turbidity caused by this release, plume dispersion predictions are often carried out. These predictions are usually executed with a large-scale model covering a complete coastal zone, bay, or estuary. A source term of fine sediments is implemented in the hydrodynamic model to simulate the fine sediment dispersion. The large-scale model mesh resolution and governing equations, however, do not allow to simulate the near-field plume behaviour in the vicinity of the ship hull and propellers. Moreover, in the near-field, these plumes are under influence of buoyancy forces and air bubbles. The initial distribution of sediments is therefore unknown and has to be based on crude assumptions at present. The initial (vertical) distribution of the sediment source is indeed of great influence on the final far-field plume dispersion results. In order to study this near-field behaviour, a highly-detailed computationally fluid dynamics (CFD) model was developed. This model contains a realistic geometry of a dredging vessel, buoyancy effects, air bubbles and propeller action, and was validated earlier by comparing with field measurements. A CFD model requires significant simulation times

  19. Effect of Arsenic on Early Chick Development

    OpenAIRE

    Zulfiqar ali laghari; Ayaz Samo; Zameer Ali Palh; Khalid Hussain Lashari; Ghulam Murtaza Mastoi

    2014-01-01

    Exposure to arsenic through drinking water is associated with the number of diseases including cancer, Increasing concentrations of toxic metals and chemicals, and their intake by humans and animals have become a major global concern of public health. Presence of these substances in drinking water is the major source of ingestion. Recent studies on pregnant females show the detrimental effects of arsenic ingestion through water. Arsenic causes fetal loss, low birth weight and miscarriages. Ho...

  20. Arsenic transport by zebrafish aquaglyceroporins

    Directory of Open Access Journals (Sweden)

    Landfear Scott M

    2009-11-01

    Full Text Available Abstract 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 named aqp3, 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, glycerol and the metalloids arsenic and antimony was examined following expression in oocytes from Xenopus leavis. Each of these channels showed substantial glycerol transport at equivalent rates. These aquaglyceroporins also facilitate uptake of inorganic AsIII, MAsIII and SbIII. Arsenic accumulation in fish larvae and in different tissues from adult zebrafish was studied following short-term arsenic exposure. The results showed that liver is the major organ of arsenic accumulation; other tissues such as gill, eye

  1. Atrazine is primarily responsible for the toxicity of long-term exposure to a combination of atrazine and inorganic arsenic in the nigrostriatal system of the albino rat.

    Science.gov (United States)

    Bardullas, Ulises; Giordano, Magda; Rodríguez, Verónica Mireya

    2013-01-01

    Chronic and simultaneous exposure to a variety of chemicals present in the environment is an unavoidable fact. However, given the complexity of studying chemical mixtures, most toxicological studies have focused on the effects of short-term exposure to single substances. The aim of this study was to evaluate the effects on the nigrostriatal system of the chronic, simultaneous exposure to two widely distributed substances that have been identified as potential dopaminergic system toxicants, inorganic arsenic (iAs) and atrazine (ATR). Six groups of rats were treated daily for one year with atrazine (10mg ATR/kg), inorganic arsenic (0.5 or 50mgiAs/L of drinking water), or a combination of ATR+0.5mgiAs/L or ATR+50mgiAs/L. The 50mgiAs/L group showed locomotor hypoactivity, while all treatments decreased motor coordination in contrast no effects of treatment were found on the place and response learning tasks. Regarding markers for liver and muscle damage, there were no differences between groups in creatine kinase (CK) or aspartate transaminase (AST) activities, while decreases in lactate dehydrogenase (LDH) levels were found in some exposed groups. The striatal DA content was significantly reduced in ATR, 0.5mgiAs/L, ATR+0.5mgiAs/L, and ATR+50mgiAs/L groups, in comparison to the control group. The number of mesencephalic tyrosine hydroxylase positive cells decreased in the ATR and ATR+0.5mgiAs/L groups compared to the control. In contrast, immunoreactivity to cytochrome oxidase was reduced compared to the control in all treated groups, except for the group treated with 0.5iAsmg alone. Our results indicate that ATR has deleterious effects on dopaminergic neurons and that the combination of ATR and iAs does not exacerbate these effects.

  2. Arsenic geochemistry of groundwater in Southeast Asia.

    Science.gov (United States)

    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.

  3. Sequestration of arsenic in ombrotrophic peatlands

    Science.gov (United States)

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

    2014-05-01

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

  4. Microbial Transformation of Arsenic

    Science.gov (United States)

    Stolz, J. F.

    2004-12-01

    Whether the source is natural or anthropogenic, it has become evident that arsenic is readily transformed by a great diversity of microbial species and has a robust biogeochemical cycle. Arsenic cycling primarily involves the oxidation of As(III) and the reduction of As(V). Over thirty arsenite oxidizing prokaryotes have been reported and include alpha, beta, and gamma Proteobacteria , Deinocci and Crenarchaeota. At least twenty species of arsenate-respiring prokaryotes are now known and include Crenarchaeota, thermophilic bacteria, low and high G+C gram positive bacteria, and gamma, delta, and epsilon Proteobacteria. These organisms are metabolically diverse, and depending on the species, capable of using other terminal electron acceptors (e.g., nitrate, selenate, fumarate, sulfate). In addition to inorganic forms (e.g., sodium arsenate) organoarsenicals can be utilized as a substrate. The feed additive roxarsone (3-nitro-4-hydroxyphenyl arsonic acid) has been shown to readily degrade leading to the release of inorganic arsenic (e.g., As(V)). Degradation proceeds via the cleavage of the arsenate functional group or the reduction of the nitro functional group and deamination. The rapid degradation (within 3 days) of roxarsone by Clostridium sp. strain OhILAs appears to follow the latter pathway and may involve Stickland reactions. The activities of these organisms affect the speciation and mobilization of arsenic, ultimately impacting water quality.

  5. ARSENIC REMOVAL FROM DRINKING WATER BY COAGULATION/FILTRATION AND LIME SOFTENING PLANTS

    Science.gov (United States)

    This report documents a long term performance (one year) study of 3 water treatment plants to remove arsenic from drinking water sources. The 3 plants consisted of 2 conventional coagulation/filtration plants and 1 lime softening plant. The study involved the collecting of weekly...

  6. Clam Ruditapes philippinarum recovery from short-term exposure to the combined effect of salinity shifts and Arsenic contamination.

    Science.gov (United States)

    Velez, Catia; Teixeira, Miguel; Wrona, Frederick J; Soares, Amadeu M V M; Figueira, Etelvina; Freitas, Rosa

    2016-04-01

    The current study assessed the biochemical alterations induced in the clam species Ruditapes philippinarum after exposure to salinity shifts (14, 28 and 42) and arsenic (As) contamination (0 and 2mg/L). The capacity of this species to recover (96h and 28 days) after exposure (96h) to both stressors, acting alone and in combination, was also evaluated. After exposure, regardless of the salinity tested, clams contaminated with As showed higher concentrations than non-contaminated specimens. After recovery, As concentration in clams decreased, with contaminated and non-contaminated specimens presenting similar values. The results obtained further demonstrated that exposure to As (2mg/L) at different salinities (salinities 14, 28 and 42) and salinity 42 (As 0mg/L) lead to an increase of lipid peroxidation and detoxification mechanisms in clams, compared with non-contaminated clams at salinities of 14 and 28. After recovery, at salinities 14 and 28, clams previously exposed to As were capable to decrease their oxidative stress to levels found in non-contaminated clams. Nevertheless, at salinity 42 both contaminated and non-contaminated clams did not survive. Overall results of measured energy-related parameters, indicators of oxidative stress, antioxidant and biotransformation enzymes indicated that As exposure and salinity shifts caused biochemical alterations in R. philippinarum, with stronger impacts when both stressors were acting in combination. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Quantification of severe accident source terms of a Westinghouse 3-loop plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee Min [Department of Engineering and System Science, and Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec II, Kung Fu Road, Hsinchu, Taiwan (China)], E-mail: mlee@mail.ess.nthu.edu.tw; Ko, Y.-C. [Department of Engineering and System Science, and Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec II, Kung Fu Road, Hsinchu, Taiwan, ROC (China)

    2008-04-15

    Integrated severe accident analysis codes are used to quantify the source terms of the representative sequences identified in PSA study. The characteristics of these source terms depend on the detail design of the plant and the accident scenario. A historical perspective of radioactive source term is provided. The grouping of radionuclides in different source terms or source term quantification tools based on TID-14844, NUREG-1465, and WASH-1400 is compared. The radionuclides release phenomena and models adopted in the integrated severe accident analysis codes of STCP and MAAP4 are described. In the present study, the severe accident source terms for risk quantification of Maanshan Nuclear Power Plant of Taiwan Power Company are quantified using MAAP 4.0.4 code. A methodology is developed to quantify the source terms of each source term category (STC) identified in the Level II PSA analysis of the plant. The characteristics of source terms obtained are compared with other source terms. The plant analyzed employs a Westinghouse designed 3-loop pressurized water reactor (PWR) with large dry containment.

  8. Role of complex organic arsenicals in food in aggregate exposure to arsenic

    Science.gov (United States)

    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 has been linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is impo...

  9. Role of complex organic arsenicals in food in aggregate exposure to arsenic

    Science.gov (United States)

    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 has been linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is impo...

  10. Arsenic chemistry in soils and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Fendorf, S.; Nico, P.; Kocar, B.D.; Masue, Y.; Tufano, K.J.

    2009-10-15

    Arsenic is a naturally occurring trace element that poses a threat to human and ecosystem health, particularly when incorporated into food or water supplies. The greatest risk imposed by arsenic to human health results from contamination of drinking water, for which the World Health Organization recommends a maximum limit of 10 {micro}g L{sup -1}. Continued ingestion of drinking water having hazardous levels of arsenic can lead to arsenicosis and cancers of the bladder, skin, lungs and kidneys. Unfortunately, arsenic tainted drinking waters are a global threat and presently having a devastating impact on human health within Asia. Nearly 100 million people, for example, are presently consuming drinking water having arsenic concentrations exceeding the World Health Organization's recommended limit (Ahmed et al., 2006). Arsenic contamination of the environment often results from human activities such as mining or pesticide application, but recently natural sources of arsenic have demonstrated a devastating impact on water quality. Arsenic becomes problematic from a health perspective principally when it partitions into the aqueous rather than the solid phase. Dissolved concentrations, and the resulting mobility, of arsenic within soils and sediments are the combined result of biogeochemical processes linked to hydrologic factors. Processes favoring the partitioning of As into the aqueous phase, potentially leading to hazardous concentrations, vary extensively but can broadly be grouped into four categories: (1) ion displacement, (2) desorption (or limited sorption) at pH values > 8.5, (3) reduction of arsenate to arsenite, and (4) mineral dissolution, particularly reductive dissolution of Fe and Mn (hydr)oxides. Although various processes may liberate arsenic from solids, a transition from aerobic to anaerobic conditions, and commensurate arsenic and iron/manganese reduction, appears to be a dominant, but not exclusive, means by which high concentrations of

  11. The Arsenic Project: A multidisciplinary Project in Nicaragua

    NARCIS (Netherlands)

    Admiraal, M.; Couasnon, A.; Huijzenveld, T.; Hutten, R.; Schölvinck, O.; Van Veen, N.

    2015-01-01

    In Nicaragua, active research for arsenic started in 1996, after the first case of arsenic poisoning was reported in a rural community. Arsenic concentrations present in drinking water cause chronic poisoning, which depending on the exposure, lead to several life-threatening long term effects. It

  12. The Arsenic Project: A multidisciplinary Project in Nicaragua

    NARCIS (Netherlands)

    Admiraal, M.; Couasnon, A.; Huijzenveld, T.; Hutten, R.; Schölvinck, O.; Van Veen, N.

    2015-01-01

    In Nicaragua, active research for arsenic started in 1996, after the first case of arsenic poisoning was reported in a rural community. Arsenic concentrations present in drinking water cause chronic poisoning, which depending on the exposure, lead to several life-threatening long term effects. It i

  13. Understanding Arsenic Dynamics in Agronomic Systems to Predict and Prevent Uptake by Crop Plants

    Science.gov (United States)

    This review is on arsenic in agronomic systems, and covers processes that influence the entry of arsenic into the human food supply. The scope is from sources of arsenic (natural and anthropogenic) in soils, biogeochemical and rhizosphere processes that control arsenic speciatio...

  14. Quantum correlations in nuclear mean field theory through source terms

    CERN Document Server

    Lee, S J

    1996-01-01

    Starting from full quantum field theory, various mean field approaches are derived systematically. With a full consideration of external source dependence, the stationary phase approximation of an action gives a nuclear mean field theory which includes quantum correlation effects (such as particle-hole or ladder diagram) in a simpler way than the Brueckner-Hartree-Fock approach. Implementing further approximation, the result can be reduced to Hartree-Fock or Hartree approximation. The role of the source dependence in a mean field theory is examined.

  15. Arsenic in Food

    Science.gov (United States)

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Food Home Food Foodborne Illness & Contaminants Metals Arsenic Share ... of the Method used to Measure Arsenic in Foods Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic, ...

  16. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Adriana [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Gamero, Procoro, E-mail: pgamerom@hotmail.com [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Almanza, Jose Manuel [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Vargas, Alfredo; Montoya, Ascencion [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, G.A. Madero, C.P. 07730, Distrito Federal (Mexico); Vargas, Gregorio [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Izquierdo, Maria [Instituto de Ciencias de la Tierra ' Jaume Almera' , CSIC, C/Luis Sole Sabaris, s/n 08028 Barcelona (Spain)

    2010-09-15

    Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 {sup o}C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na{sub 2}HAsO{sub 4}.7H{sub 2}O originally containing 740 ppb.

  17. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption.

    Science.gov (United States)

    Medina, Adriana; Gamero, Prócoro; Almanza, José Manuel; Vargas, Alfredo; Montoya, Ascención; Vargas, Gregorio; Izquierdo, María

    2010-09-15

    Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 degrees C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na(2)HAsO(4).7H(2)O originally containing 740 ppb.

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

    Science.gov (United States)

    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.

  19. Presence of Arsenic in Commercial Beverages

    Directory of Open Access Journals (Sweden)

    Jason Roberge

    2009-01-01

    Full Text Available Problem statement: This study’s goal was to assess the arsenic concentration of various beverages and broths purchased from a local chain supermarket. A source of chronic arsenic exposure occurs via food and beverage consumption. Groundwater levels of total arsenic are regulated (-1 by the Environmental Protection Agency (EPA but few studies have examined arsenic concentrations in common beverages. Approach: In the initial analysis of 19 items, total arsenic concentration was assessed from a variety of fruit juices, sports drinks, sodas and broths. Items found to contain levels of total arsenic ≥5.0 µg L-1 were further evaluated. Additional analysis included purchasing multiple brands of items ≥5.0 µg L-1and analyzing them for total arsenic and chemical species of arsenic. Results: Among the beverages in the initial analysis, apple juice (10.79 µg L-1 and grape juice (49.87 µg L-1 contained the highest levels of total arsenic. Upon examination of items with As concentrations above 5.0 µg L-1, varying concentrations of total arsenic were found in apple cider (range: 5.41-15.27 µg L-1, apple juice (range: 10.67-22.35 µg L-1, baby fruit juice (range: 13.91-16.51 µg L-1 and grape juice (range: 17.69-47.59 µg L-1. Conclusion: Many commercially available juices contained concentrations of arsenic that were higher than the standard for total arsenic allowed in groundwater as set forth by the EPA. The concentration of As in these juices varied between and within brands. In general, those consuming apple and grape juices are the young and elderly and it is these populations that may be more vulnerable to over exposure of heavy metals.

  20. Arsenic bioaccessibility and speciation in the soils amended with organoarsenicals and drinking-water treatment residuals based on a long-term greenhouse study

    Science.gov (United States)

    Nagar, Rachana; Sarkar, Dibyendu; Makris, Konstantinos C.; Datta, Rupali

    2014-10-01

    SummaryAlthough organoarsenical pesticides are no longer applied to agricultural fields in the US, their widespread use until recently, toxicity, and potential transformation to inorganic arsenic has raised serious concern. Drinking-water treatment residuals (WTRs) have been proposed as a low-cost amendment for remediation of organoarsenical pesticide contaminated soils. A long-term greenhouse study was initiated to evaluate the effect WTR application on bioaccessibility, geochemical partitioning, and speciation of the Dimethylarsinic acid (DMA). Two soils (Immokalee and Orelia series) were spiked with DMA (1500 mg As kg-1) and amended with an Al- and Fe-based WTR at two rates (5% and 10% by wt.). Soil sampling was done immediately after spiking (time zero) and after 0.25, 0.5, 1, and 3 (time final) years of equilibration and subjected to bioaccessibility test and sequential extraction. Results showed that compared to the unamended (no WTR) control, As bioaccessibility in the WTR-amended soils significantly (p soil As bioaccessibility. The in vitro and water-extracted samples were subjected to As speciation at time zero and time final. Results showed transformation of DMA into inorganic As, irrespective of WTR amendments. The Orelia soil showed significantly (p soil.

  1. CHALLENGES IN SOURCE TERM MODELING OF DECONTAMINATION AND DECOMMISSIONING WASTES.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.M.

    2006-08-01

    Development of real-time predictive modeling to identify the dispersion and/or source(s) of airborne weapons of mass destruction including chemical, biological, radiological, and nuclear material in urban environments is needed to improve response to potential releases of these materials via either terrorist or accidental means. These models will also prove useful in defining airborne pollution dispersion in urban environments for pollution management/abatement programs. Predicting gas flow in an urban setting on a scale of less than a few kilometers is a complicated and challenging task due to the irregular flow paths that occur along streets and alleys and around buildings of different sizes and shapes, i.e., ''urban canyons''. In addition, air exchange between the outside and buildings and subway areas further complicate the situation. Transport models that are used to predict dispersion of WMD/CBRN materials or to back track the source of the release require high-density data and need defensible parameterizations of urban processes. Errors in the data or any of the parameter inputs or assumptions will lead to misidentification of the airborne spread or source release location(s). The need for these models to provide output in a real-time fashion if they are to be useful for emergency response provides another challenge. To improve the ability of New York City's (NYC's) emergency management teams and first response personnel to protect the public during releases of hazardous materials, the New York City Urban Dispersion Program (UDP) has been initiated. This is a four year research program being conducted from 2004 through 2007. This paper will discuss ground level and subway Perfluorocarbon tracer (PFT) release studies conducted in New York City. The studies released multiple tracers to study ground level and vertical transport of contaminants. This paper will discuss the results from these tests and how these results can be used

  2. Exposure to inorganic arsenic in soil increases urinary inorganic arsenic concentrations of residents living in old mining areas.

    Science.gov (United States)

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

    2004-03-01

    The short term human exposure studies conducted on populations exposed to high concentrations of inorganic arsenic in soil have been inconsistent in demonstrating a relationship between environmental concentrations and exposure measures. In Australia there are many areas with very high arsenic concentrations in residential soil most typically associated with gold mining activities in rural areas. This study aimed to investigate the relationship between environmental arsenic and urinary inorganic arsenic concentrations in a population living in a gold mining area (soil arsenic concentrations between 9 and 9900 mg kg(-1)), and a control population with low arsenic levels in soil (between 1 and 80 mg kg(-1)). Risk factors for increased urinary arsenic concentrations were also explored. There was a weak but significant relationship between soil arsenic concentrations and inorganic urinary arsenic concentration with a Spearman correlation coefficient of 0.39. When participants with greater than 100 mg kg(-1) arsenic in residential soil were selected, the coefficient increased to 0.64. The geometric mean urinary inorganic arsenic concentration for the exposed group was 1.64 microg L(-1) (risk factors. These results show that high concentrations of arsenic in soil can make a contribution to urinary inorganic arsenic concentrations.

  3. Arsenic in groundwater of the Kolkata Municipal Corporation (KMC), India: Critical review and modes of mitigation.

    Science.gov (United States)

    Chakraborti, Dipankar; Das, Bhaskar; Rahman, Mohammad Mahmudur; Nayak, Bishwajit; Pal, Arup; Sengupta, Mrinal K; Ahamed, Sad; Hossain, Md Amir; Chowdhury, Uttam K; Biswas, Bhajan Kumar; Saha, Khitish Chandra; Dutta, R N

    2017-08-01

    This study represents the first comprehensive report of groundwater arsenic contamination status in the Kolkata Municipal Corporation (KMC). During the past 23 years, 4210 groundwater samples were analysed from all 141 wards in the KMC: 14.2% and 5.2% samples had arsenic >10 μg/l and >50 μg/l, respectively, representing 77 and 37 wards. The study shows that the number of arsenic contaminated samples (and wards) in the southern part of the KMC exceeds that of other parts of the city. The daily intake of arsenic from drinking water was estimated as 0.95 μg per kg bw and the cancer risk was estimated as 1425/10(6). Analyses of biological samples (hair, nail and urine) showed elevated concentrations of arsenic indicating the presence of subclinical arsenic poisoning, predicting an enhanced lifetime cancer risk for the population in southern part of the KMC. In the KMC, groundwater is not a sustainable source of freshwater due to arsenic, high iron, hardness and total dissolved solids. Its continued use is impelled by the lack of an adequate infrastructure to treat and supply surface water and in some wards the unaccounted for water (UFW) is even >45% incurred during distribution. The rare imposition of a water tax makes the water supply systems unsustainable and fosters indifference to water conservation. To mitigate the arsenic problem, continuous groundwater monitoring for pollutants, a treated surface water supply with strict policy implications, rainwater harvesting in the urban areas and introduction of water taxes seem to be long-term visible solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. 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.

    Science.gov (United States)

    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 arsenic intake (p 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.

  5. Application of a new source term at Grand Gulf nuclear station

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, G.E.; Withrow, M.D. [Entergy Operations, Inc., Port Gibson, MS (United States)

    1997-12-01

    The NUREG and a number of companion regulatory guidance documents and methodologies establish new design basis accident source terms that individual existing BWR type reactor licensees may choose to adopt. These new source terms constitute the first major change in regulatory requirements.

  6. Arsenic and human health effects: A review.

    Science.gov (United States)

    Abdul, Khaja Shameem Mohammed; Jayasinghe, Sudheera Sammanthi; Chandana, Ediriweera P S; Jayasumana, Channa; De Silva, P Mangala C S

    2015-11-01

    Arsenic (As) is ubiquitous in nature and humans being exposed to arsenic via atmospheric air, ground water and food sources are certain. Major sources of arsenic contamination could be either through geological or via anthropogenic activities. In physiological individuals, organ system is described as group of organs that transact collectively and associate with other systems for conventional body functions. Arsenic has been associated with persuading a variety of complications in body organ systems: integumentary, nervous, respiratory, cardiovascular, hematopoietic, immune, endocrine, hepatic, renal, reproductive system and development. In this review, we outline the effects of arsenic on the human body with a main focus on assorted organ systems with respective disease conditions. Additionally, underlying mechanisms of disease development in each organ system due to arsenic have also been explored. Strikingly, arsenic has been able to induce epigenetic changes (in utero) and genetic mutations (a leading cause of cancer) in the body. Occurrence of various arsenic induced health effects involving emerging areas such as epigenetics and cancer along with their respective mechanisms are also briefly discussed.

  7. Atmospheric deposition of trace elements around point sources and human health risk assessment. II: Uptake of arsenic and chromium by vegetables grown near a wood preservation factory

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Moseholm, Lars; Nielsen, Margot M.

    1992-01-01

    Kale, lettuce, carrots and potatoes were grown in 20 experimental plots surrounding a wood preservation factory, to investigate the amount and pathways for plant uptake of arsenic and chromium. Arsenate used in the wood preservation process is converted to the more toxic arsenite by incineration...... of waste wood and is emitted into the atmosphere. Elevated concentrations of inorganic arsenic and chromium were found both in the test plants and in the soil around the factory. Multivariate statistical analysis of the results indicated that the dominating pathway of arsenic and chromium from the factory...

  8. Human Arsenic Poisoning Issues in Central-East Indian Locations: Biomarkers and Biochemical Monitoring

    Directory of Open Access Journals (Sweden)

    Madhurima Pandey

    2007-03-01

    Full Text Available 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.

  9. Enhancing the removal of arsenic, boron and heavy metals in subsurface flow constructed wetlands using different supporting media.

    Science.gov (United States)

    Allende, K Lizama; Fletcher, T D; Sun, G

    2011-01-01

    The presence of arsenic and heavy metals in drinking water sources poses a serious health risk due to chronic toxicological effects. Constructed wetlands have the potential to remove arsenic and heavy metals, but little is known about pollutant removal efficiency and reliability of wetlands for this task. This lab-scale study investigated the use of vertical subsurface flow constructed wetlands for removing arsenic, boron, copper, zinc, iron and manganese from synthetic wastewater. Gravel, limestone, zeolite and cocopeat were employed as wetland media. Conventional gravel media only showed limited capability in removing arsenic, iron, copper and zinc; and it showed virtually no capability in removing manganese and boron. In contrast, alternative wetland media: cocopeat, zeolite and limestone, demonstrated significant efficiencies--in terms of percentage removal and mass rate per m3 of wetland volume--for removing arsenic, iron, manganese, copper and zinc; their ability to remove boron, in terms of mass removal rate, was also higher than that of the gravel media. The overall results demonstrated the potential of using vertical flow wetlands to remove arsenic and metals from contaminated water, having cocopeat, zeolite or limestone as supporting media.

  10. Source term reduction at DAEC (including stellite ball recycling)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.; Schebler, D. [Duane Arnold Energy Center, Palo, IA (United States)

    1995-05-01

    The Duane Arnold Energy Center was seeking methods to reduce dose rates from the drywell due to Co-60. Duane Arnold is known in the industry to have one of the highest drywell dose rates from the industry standardized `BRAC` point survey. A prime method to reduce dose rates due to Co-60 is the accelerated replacement of stellite pins and rollers in control rod blades due to their high stellite (cobalt) content. Usually the cobalt content in alloys of stellite is greater than 60% cobalt by weight. During the RFO-12 refueling outage at Duane Arnold, all of the remaining cobalt bearing control rod blades were replaced and new stellite free control rod blades were installed in the core. This left Duane Arnold with the disposal of highly radioactive stellite pins and rollers. The processing of control rod blades for disposal is a very difficult evolution. First, the velocity limiter (a bottom portion of the component) and the highly radioactive upper stellite control rod blade ins and rollers are separated from the control rod blade. Next, the remainder of the control rod blade is processed (chopped and/or crushed) to aid packaging the waste for disposal. The stellite bearings are then often carefully placed in with the rest of the waste in a burial liner to provide shielding for disposal or more often are left as `orphans` in the spent fuel pool because their high specific activity create shipping and packaging problems. Further investigation by the utility showed that the stellite balls and pins could be recycled to a source manufacturer rather than disposed of in a low-level burial site. The cost savings to the utility was on the order of $200,000 with a gross savings of $400,000 in savings in burial site charges. A second advantage of the recycling of the stellite pins and rollers was a reduction in control in radioactive waste shipments.

  11. Chronic arsenic intoxication diagnostic score (CAsIDS).

    Science.gov (United States)

    Dani, Sergio Ulhoa; Walter, Gerhard Franz

    2017-08-31

    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.

  12. Health hazards and mitigation of chronic poisoning from arsenic in drinking water: Taiwan experiences.

    Science.gov (United States)

    Chen, Chien-Jen

    2014-01-01

    There are two endemic areas of long-term exposure to arsenic from drinking water in Taiwan. Residents in the southwestern and northeastern endemic areas started using high-arsenic artesian well water in the early 1910s and late 1940s, respectively. Public water supply system using surface water was implemented in southwestern and northeastern endemic areas in the 1970s and 1990s, respectively. Systemic health hazards of long-term exposure to arsenic in drinking water have been intensively investigated since the 1960s, especially after 1985 in Taiwan. Several diseases have been well documented to be associated with chronic arsenic poisoning from drinking water showing a dose-response relation. They include characteristic skin lesions like hyperpigmentation or depigmentation, hyperkeratosis in palms and soles, and Bowen disease, peripheral vascular disease (specifically blackfoot disease), ischemic heart disease, cerebral infarction, microvascular diseases, abnormal peripheral microcirculation, carotid atherosclerosis, QT prolongation and increased dispersion in electrocardiography, hypertension, goiter, diabetes mellitus, cataract (specifically posterior subcapsular lens opacity), pterygium, slow neural conduction, retarded neurobehavioral development, erectile dysfunction, and cancers of the skin, lung, urinary bladder, kidney, and liver. The method of choice to mitigate arsenic poisoning through drinking water is to use safe drinking water from uncontaminated sources.

  13. Using Bayesian Belief Network (BBN) modelling for Rapid Source Term Prediction. RASTEP Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Alfheim, P. [Scandpower AB, Sundbyberg (Sweden)

    2012-09-15

    The project is connected to the development of RASTEP, a computerized source term prediction tool aimed at providing a basis for improving off-site emergency management. RASTEP uses Bayesian belief networks (BBN) to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, timing, and pathway of released radio-nuclides). The output is a set of possible source terms with associated probabilities. In the NKS project, a number of complex issues associated with the integration of probabilistic and deterministic analyses are addressed. This includes issues related to the method for estimating source terms, signal validation, and sensitivity analysis. One major task within Phase 1 of the project addressed the problem of how to make the source term module flexible enough to give reliable and valid output throughout the accident scenario. Of the alternatives evaluated, it is recommended that RASTEP is connected to a fast running source term prediction code, e.g., MARS, with a possibility of updating source terms based on real-time observations. (Author)

  14. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

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

    2014-05-01

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

  15. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

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

    2015-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice. PMID:26778863

  16. Recent advances in the source term area within the SARNET European severe accident research network

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L.E., E-mail: luisen.herranz@ciemat.es [Centro de Investigaciones Energeticas Medio Ambientales y Tecnologica, CIEMAT, Avda. Complutense 40, E-28040 Madrid (Spain); Haste, T. [Institut de Radioprotection et de Sûreté Nucléaire, IRSN, BP 3, F-13115 St Paul lez Durance Cedex (France); Kärkelä, T. [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT Espoo (Finland)

    2015-07-15

    Highlights: • Main achievements of source term research in SARNET are given. • Emphasis on the radiologically important iodine and ruthenium fission products. • Conclusions on FP release, transport in the RCS and containment behaviour. • Significance of large-scale integral experiments to validate the analyses used. • A thorough list of the most recent references on source term research results. - Abstract: Source Term has been one of the main research areas addressed within the SARNET network during the 7th EC Framework Programme of EURATOM. The entire source term domain was split into three major areas: oxidising impact on source term, iodine chemistry in the reactor coolant system and containment and data and code assessment. The present paper synthesises the main technical outcome stemming from the SARNET FWP7 project in the area of source term and includes an extensive list of references in which deeper insights on specific issues may be found. Besides, based on the analysis of the current state of the art, an outlook of future source term research is outlined, where major changes in research environment are discussed (i.e., the end of the Phébus FP project; the end of the SARNET projects; and the launch of HORIZON 2020). Most probably research projects will be streamlined towards: release and transport under oxidising conditions, containment chemistry, existing and innovative filtered venting systems and others. These will be in addition to a number of projects that have been completed or are ongoing under different national and international frameworks, like VERDON, CHIP and EPICUR started under the International Source Term Programme (ISTP), the OECD/CSNI programmes BIP, BIP2, STEM, THAI and THAI2, and the French national programme MIRE. The experimental PASSAM project under the 7th EC Framework programme, focused on source term mitigation systems, is highlighted as a good example of a project addressing potential enhancement of safety systems

  17. Establishment of Groundwater Arsenic Potential Distribution and Discrimination in Taiwan

    Science.gov (United States)

    Tsai, Kuo Sheng; Chen, Yu Ying; Chung Liu, Chih; Lin, Chien Wen

    2016-04-01

    According to the last 10 years groundwater monitoring data in Taiwan, Arsenic concentration increase rapidly in some areas, similar to Bengal and India, the main source of Arsenic-polluted groundwater is geological sediments, through reducing reactions. There are many researches indicate that high concentration of Arsenic in groundwater poses the risk to water safety, for example, the farm lands irrigation water contains Arsenic cause the concentration of Arsenic increase in soil and crops. Based on the management of water usage instead of remediation in the situation of insufficient water. Taiwan EPA has been developed the procedures of Arsenic contamination potential area establishment and source discriminated process. Taiwan EPA use the procedures to determine the management of using groundwater, and the proposing usage of Arsenic groundwater accordance with different objects. Agencies could cooperate with the water quality standard or water needs, studying appropriate water purification methods and the groundwater depth, water consumption, thus achieve the goal of water safety and environmental protection, as a reference of policy to control total Arsenic concentration in groundwater. Keywords: Arsenic; Distribution; Discrimination; Pollution potential area of Arsenic; Origin evaluation of groundwater Arsenic

  18. ARSENIC CONTAMINATION IN DRINKING WATER: AN ASSESSMENT FOR TURKEY

    Directory of Open Access Journals (Sweden)

    Meltem BİLİCİ ÇALIŞKAN

    2009-01-01

    Full Text Available Arsenic is one of the most abundant elements in the earth's crust and classified as a non-metal or a metalloid. Arsenic is toxic and carcinogen and in the environment occurs from both natural and anthropogenic sources. In the aqueous environment inorganic arsenic appears commonly in forms of arsenite (As(III and arsenate (As(V. pH, redox potential, and the presence of complexing ions such as ions of sulfur, iron, and calcium determine the arsenic valence and speciation. Because of the naturally occurring arsenic contamination in groundwater in many parts of the world many people have faced with risk of arsenic poisoning. In Turkey especially in the west regions, natural water sources contained much higher levels of arsenic than maximum contaminated level (MCL set (10 ?g/L were determined. In this study, arsenic problem and its reasons in Turkey were investigated. For this purpose, arsenic analyses were carried out and higher levels of arsenic than MCL was detected in some regions of Izmir. High levels of arsenic in these natural waters were considered to be associated with the dissolution of some minerals and rock formation.

  19. Earth Abides Arsenic Biotransformations

    OpenAIRE

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

    2014-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology ...

  20. Development of source term evaluation method for Korean Next Generation Reactor(III)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Jae; Park, Jin Baek; Lee, Yeong Il; Song, Min Cheonl; Lee, Ho Jin [Korea Advanced Institue of Science and Technology, Taejon (Korea, Republic of)

    1998-06-15

    This project had investigated irradiation characteristics of MOX fuel method to predict nuclide concentration at primary and secondary coolant using a core containing 100% of all MOX fuel and development of source term evaluation tool. In this study, several prediction methods of source term are evaluated. Detailed contents of this project are : an evaluation of model for nuclear concentration at Reactor Coolant System, evaluation of primary and secondary coolant concentration of reference Nuclear Power Plant using purely MOX fuel, suggestion of source term prediction method of NPP with a core using MOX fuel.

  1. Source term model evaluations for the low-level waste facility performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S.; Su, S.I. [North Carolina State Univ., Raleigh, NC (United States)

    1995-12-31

    The estimation of release of radionuclides from various waste forms to the bottom boundary of the waste disposal facility (source term) is one of the most important aspects of LLW facility performance assessment. In this work, several currently used source term models are comparatively evaluated for the release of carbon-14 based on a test case problem. The models compared include PRESTO-EPA-CPG, IMPACTS, DUST and NEFTRAN-II. Major differences in assumptions and approaches between the models are described and key parameters are identified through sensitivity analysis. The source term results from different models are compared and other concerns or suggestions are discussed.

  2. Development of source term evaluation method for Korean Next Generation Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Keon Jae; Cheong, Jae Hak; Park, Jin Baek; Kim, Guk Gee [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-10-15

    This project had investigate several design features of radioactive waste processing system and method to predict nuclide concentration at primary coolant basic concept of next generation reactor and safety goals at the former phase. In this project several prediction methods of source term are evaluated conglomerately and detailed contents of this project are : model evaluation of nuclide concentration at Reactor Coolant System, evaluation of primary and secondary coolant concentration of reference Nuclear Power Plant(NPP), investigation of prediction parameter of source term evaluation, basic parameter of PWR, operational parameter, respectively, radionuclide removal system and adjustment values of reference NPP, suggestion of source term prediction method of next generation NPP.

  3. Water quality monitoring records for estimating tap water arsenic and nitrate: a validation study

    Directory of Open Access Journals (Sweden)

    Kuehn Carrie M

    2010-01-01

    Full Text Available Abstract Background Tap water may be an important source of exposure to arsenic and nitrate. Obtaining and analyzing samples in the context of large studies of health effects can be expensive. As an alternative, studies might estimate contaminant levels in individual homes by using publicly available water quality monitoring records, either alone or in combination with geographic information systems (GIS. Methods We examined the validity of records-based methods in Washington State, where arsenic and nitrate contamination is prevalent but generally observed at modest levels. Laboratory analysis of samples from 107 homes (median 0.6 μg/L arsenic, median 0.4 mg/L nitrate as nitrogen served as our "gold standard." Using Spearman's rho we compared these measures to estimates obtained using only the homes' street addresses and recent and/or historical measures from publicly monitored water sources within specified distances (radii ranging from one half mile to 10 miles. Results Agreement improved as distance decreased, but the proportion of homes for which we could estimate summary measures also decreased. When including all homes, agreement was 0.05-0.24 for arsenic (8 miles, and 0.31-0.33 for nitrate (6 miles. Focusing on the closest source yielded little improvement. Agreement was greatest among homes with private wells. For homes on a water system, agreement improved considerably if we included only sources serving the relevant system (ρ = 0.29 for arsenic, ρ = 0.60 for nitrate. Conclusions Historical water quality databases show some promise for categorizing epidemiologic study participants in terms of relative tap water nitrate levels. Nonetheless, such records-based methods must be used with caution, and their use for arsenic may be limited.

  4. Induction of Human Squamous Cell-Type Carcinomas by Arsenic

    Directory of Open Access Journals (Sweden)

    Victor D. Martinez

    2011-01-01

    Full Text Available Arsenic is a potent human carcinogen. Around one hundred million people worldwide have potentially been exposed to this metalloid at concentrations considered unsafe. Exposure occurs generally through drinking water from natural geological sources, making it difficult to control this contamination. Arsenic biotransformation is suspected to have a role in arsenic-related health effects ranging from acute toxicities to development of malignancies associated with chronic exposure. It has been demonstrated that arsenic exhibits preference for induction of squamous cell carcinomas in the human, especially skin and lung cancer. Interestingly, keratins emerge as a relevant factor in this arsenic-related squamous cell-type preference. Additionally, both genomic and epigenomic alterations have been associated with arsenic-driven neoplastic process. Some of these aberrations, as well as changes in other factors such as keratins, could explain the association between arsenic and squamous cell carcinomas in humans.

  5. Existence and Asymptotic Stability of Solutions for Hyperbolic Differential Inclusions with a Source Term

    Directory of Open Access Journals (Sweden)

    Park Jong Yeoul

    2007-01-01

    Full Text Available We study the existence of global weak solutions for a hyperbolic differential inclusion with a source term, and then investigate the asymptotic stability of the solutions by using Nakao lemma.

  6. Accident source terms for boiling water reactors with high burnup cores.

    Energy Technology Data Exchange (ETDEWEB)

    Gauntt, Randall O.; Powers, Dana Auburn; Leonard, Mark Thomas

    2007-11-01

    The primary objective of this report is to provide the technical basis for development of recommendations for updates to the NUREG-1465 Source Term for BWRs that will extend its applicability to accidents involving high burnup (HBU) cores. However, a secondary objective is to re-examine the fundamental characteristics of the prescription for fission product release to containment described by NUREG-1465. This secondary objective is motivated by an interest to understand the extent to which research into the release and behaviors of radionuclides under accident conditions has altered best-estimate calculations of the integral response of BWRs to severe core damage sequences and the resulting radiological source terms to containment. This report, therefore, documents specific results of fission product source term analyses that will form the basis for the HBU supplement to NUREG-1465. However, commentary is also provided on observed differences between the composite results of the source term calculations performed here and those reflected NUREG-1465 itself.

  7. Source terms: an investigation of uncertainties, magnitudes, and recommendations for research. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Levine, S.; Kaiser, G. D.; Arcieri, W. C.; Firstenberg, H.; Fulford, P. J.; Lam, P. S.; Ritzman, R. L.; Schmidt, E. R.

    1982-03-01

    The purpose of this document is to assess the state of knowledge and expert opinions that exist about fission product source terms from potential nuclear power plant accidents. This is so that recommendations can be made for research and analyses which have the potential to reduce the uncertainties in these estimated source terms and to derive improved methods for predicting their magnitudes. The main reasons for writing this report are to indicate the major uncertainties involved in defining realistic source terms that could arise from severe reactor accidents, to determine which factors would have the most significant impact on public risks and emergency planning, and to suggest research and analyses that could result in the reduction of these uncertainties. Source terms used in the conventional consequence calculations in the licensing process are not explicitly addressed.

  8. Source terms: an investigation of uncertainties, magnitudes, and recommendations for research. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Levine, S.; Kaiser, G. D.; Arcieri, W. C.; Firstenberg, H.; Fulford, P. J.; Lam, P. S.; Ritzman, R. L.; Schmidt, E. R.

    1982-03-01

    The purpose of this document is to assess the state of knowledge and expert opinions that exist about fission product source terms from potential nuclear power plant accidents. This is so that recommendations can be made for research and analyses which have the potential to reduce the uncertainties in these estimated source terms and to derive improved methods for predicting their magnitudes. The main reasons for writing this report are to indicate the major uncertainties involved in defining realistic source terms that could arise from severe reactor accidents, to determine which factors would have the most significant impact on public risks and emergency planning, and to suggest research and analyses that could result in the reduction of these uncertainties. Source terms used in the conventional consequence calculations in the licensing process are not explicitly addressed.

  9. Importance of As(V)-iron oxides complexes in retention mechanisms of arsenic in soils

    Science.gov (United States)

    Cancès, B.; Laperche, V.; Juillot, F.; Morin, G.; Calas, G.

    2003-04-01

    The knowledge of arsenic speciation in environmental system is primordial since the mobility and toxicity of this element strongly depends on its chemical form (oxidation state, molecular environment). The objective of the present study is to compare the arsenic speciation in recently polluted soils and in their long term natural analogues in order to identify major As-bearing mineral phases controlling the fate of arsenic in soils. Our approach, which combines conventional techniques (XRD, SEM-EDS) with X-ray Absorption Spectroscopy (EXAFS and XANES), provides the possibility of measuring changes of arsenic speciation as a function of soil horizons. At this step of the study, two soil profiles were investigated : The first one is located in the vicinity of a former arsenical pesticides manufactory (Auzon, France). The other one has developed over a geochemical anomaly (Echassières, France) and can be considered as a long term analogue for polluted soils. In the first soil studied, the main source of arsenic comes from the topsoil through the dissolution of pesticides (Schulténite PbHAsO4 and alumopharmacosidérite KAl4(AsO4)3(OH)5.6,5H2O) or/and of As sulfides (realgar AsS and orpiment As2S3). In the second one, arsenic comes from the geological substratum through the dissolution of pharmacosiderite ((Bax,K2-2x)(Fe, Al)4(AsO4)3(OH)5.6H2O formed by hydrothermal weathering of arsenopyrite (FeAsS) and löllingite (FeAs2). Despite these contrasted sources and ways of dissemination, our results indicate that arsenic is mainly present as As(V) co-precipitated with, or adsorbed on poorly ordered iron (oxihydr)oxides, such as ferrihydrite in topsoil horizon of both soil profiles. This study emphasizes the importance of iron (oxihydr)oxides in the trapping of arsenic released in the environment, provided the persistence of acidic and oxidizing soil conditions.

  10. Spent Fuel Source Term Calculation of Daya Bay Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    XU; Zhi-long; WAN; Hai-xia; LI; Long; WU; Xiao-chun; SHAO; Jing; LIU; Li-li; ZHANG; Jing

    2013-01-01

    The spent fuel of nuclear power plant should be transported to reprocessing plant for reprocessing after reserving for a period of time.Before that,safety analysis and environmental impact assessment should be carried on to the transportation process,which need radioactive source term calculation and analysis.The task of Daya Bay Nuclear Power Plant spent fuel source term calculation includes estimation of

  11. CFD Analysis of Migration Mechanism of Source Term Under Severe Accident

    Institute of Scientific and Technical Information of China (English)

    CHEN; Lin-lin; SUN; Xue-ting; JI; Song-tao

    2013-01-01

    The analysis of the migration of source term under severe accident is one of the important aspects of‘Studies on Migration Mechanism of the Source Term under Severe Accident’,which is a significant task of the National Large Advanced PWR Research Program.This research aims at building up a method for analyzing fission product behavior in the containment with CFD code.The effect of PCCS(Passive

  12. MELCOR code source term characteristics for fast SBO scenario of OPR1000 plant

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seok Jung; Kim, Tae Woon; Park, Sun Hee; Ahn, Kwang Il [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Off site consequence analysis in Level 3 PSA is mainly affected by source terms release characteristics of nuclear plant. The severe accidents analysis codes for quantifying the source terms release characteristics, such as MELCOR or MAAP, could be available to provide the detailed information of these characteristics to assess offsite consequence. To utilize these characteristics from severe accident analysis codes, MELCOR code was used in a specific severe accident scenario, i.e., fast station black out (SBO) for OPR1000 plant.

  13. Recent advances in the bioremediation of arsenic-contaminated groundwater.

    Science.gov (United States)

    Zouboulis, Anastasios I; Katsoyiannis, Ioannis A

    2005-02-01

    The biological treatment of groundwater is used primarily to remove electron donors from water sources, providing (biologically) stable drinking water, which preclude bacterial regrowth during subsequent water distribution. To the electron donors belong also the dissolved metal cations of ferrous iron and manganese, which are common contaminants found in most (anaerobic) groundwater. The removal of iron and manganese is usually accomplished by the application of chemical oxidation and filtration. However, biological oxidation has recently gained increased importance and application due to the existence of certain advantages, over the conventional physicochemical treatment. The oxidation of iron and manganese is accelerated by the presence of certain indigenous bacteria, the so-called "iron and manganese oxidizing bacteria." In the present paper, selected long-term experimental results will be presented, regarding the bioremediation of natural groundwater, containing elevated concentrations of iron and arsenic. Arsenic is considered as a primary pollutant in drinking water due to its high toxicity. Therefore, its efficient removal from natural waters intended for drinking water is considered of great importance. The application of biological processes for the oxidation and removal of dissolved iron was found to be an efficient treatment technique for the simultaneous removal of arsenic, from initial concentrations between 60 and 80 microg/l to residual (effluent) arsenic concentrations lower than the limit of 10 microg/l. The paper was focused on the removal of As(III) as the most common species in anaerobic groundwater and generally is removed less efficiently than the oxidized form of As(V). To obtain information for the mechanism of As(III) removal, X-ray photoelectron spectroscopy (XPS) analyses were applied and it was found that As(III) was partially oxidized to As(V), which enabled the high arsenic removal efficiency over a treatment period of 10 months.

  14. Backup Sourcing Decisions for Coping with Supply Disruptions under Long-Term Horizons

    OpenAIRE

    Jing Hou; Lijun Sun

    2016-01-01

    This paper studies a buyer’s inventory control problem under a long-term horizon. The buyer has one major supplier that is prone to disruption risks and one backup supplier with higher wholesale price. Two kinds of sourcing methods are available for the buyer: single sourcing with/without contingent supply and dual sourcing. In contingent sourcing, the backup supplier is capacitated and/or has yield uncertainty, whereas in dual sourcing the backup supplier has an incentive to offer output fle...

  15. Fission Product Appearance Rate Coefficients in Design Basis Source Term Determinations - Past and Present

    Science.gov (United States)

    Perez, Pedro B.; Hamawi, John N.

    2017-09-01

    Nuclear power plant radiation protection design features are based on radionuclide source terms derived from conservative assumptions that envelope expected operating experience. Two parameters that significantly affect the radionuclide concentrations in the source term are failed fuel fraction and effective fission product appearance rate coefficients. Failed fuel fraction may be a regulatory based assumption such as in the U.S. Appearance rate coefficients are not specified in regulatory requirements, but have been referenced to experimental data that is over 50 years old. No doubt the source terms are conservative as demonstrated by operating experience that has included failed fuel, but it may be too conservative leading to over-designed shielding for normal operations as an example. Design basis source term methodologies for normal operations had not advanced until EPRI published in 2015 an updated ANSI/ANS 18.1 source term basis document. Our paper revisits the fission product appearance rate coefficients as applied in the derivation source terms following the original U.S. NRC NUREG-0017 methodology. New coefficients have been calculated based on recent EPRI results which demonstrate the conservatism in nuclear power plant shielding design.

  16. Backup Sourcing Decisions for Coping with Supply Disruptions under Long-Term Horizons

    Directory of Open Access Journals (Sweden)

    Jing Hou

    2016-01-01

    Full Text Available This paper studies a buyer’s inventory control problem under a long-term horizon. The buyer has one major supplier that is prone to disruption risks and one backup supplier with higher wholesale price. Two kinds of sourcing methods are available for the buyer: single sourcing with/without contingent supply and dual sourcing. In contingent sourcing, the backup supplier is capacitated and/or has yield uncertainty, whereas in dual sourcing the backup supplier has an incentive to offer output flexibility during disrupted periods. The buyer’s expected cost functions and the optimal base-stock levels using each sourcing method under long-term horizon are obtained, respectively. The effects of three risk parameters, disruption probability, contingent capacity or uncertainty, and backup flexibility, are examined using comparative studies and numerical computations. Four sourcing methods, namely, single sourcing with contingent supply, dual sourcing, and single sourcing from either of the two suppliers, are also compared. These findings can be used as a valuable guideline for companies to select an appropriate sourcing strategy under supply disruption risks.

  17. Arsenic in the environment: enrichments in the Slovenian soils

    Directory of Open Access Journals (Sweden)

    Mateja Gosar

    2005-12-01

    Full Text Available Arsenic, a toxic element with metalloid properties, is found in detectable concentrations in environmental samples. In nature it is enriched in metal (sulphide ore deposits, mainly as arsenides of Cu, Ni and Fe. Arsenic compounds are used mainly in agricultureand forestry as pesticides and herbicides. The ecosystem can be contaminated with arsenic via both natural and anthropogenic sources. Uses of arsenic contaminated water present so far the greatest health hazard. Occurrences of mining related arsenic problems havealso been recorded in many parts of the world.The impact of mining and metallurgic industry with regard to arsenic contents in soils in some potentially contaminated areas in Slovenia is discussed. Enriched contents of arsenic were found in Mežica. Arsenic correlates very well with lead, zinc and other heavymetals which are enriched as a result of long lasting lead production in the area. Also in Celje and Jesenice arsenic has the same distribution pattern as other anthropogenically introduced pollutants. In Idrija there are some slightly arsenic enriched areas, but there is no correlation with mercury, so the origin of arsenic in not clear yet.

  18. Arsenic load in rice ecosystem and its mitigation through deficit irrigation.

    Science.gov (United States)

    Mukherjee, Arkabanee; Kundu, M; Basu, B; Sinha, B; Chatterjee, M; Bairagya, M Das; Singh, U K; Sarkar, S

    2017-07-15

    Rice the staple food is a notable intake source of arsenic to the rural population of eastern India through food-chain. A field survey was carried out to study the variation of arsenic load in different parts of rice genotype Shatabdi (most popular genotype of the region) exposed to varying level of arsenic present in the irrigation water and soil. As irrigation is the primary source of arsenic contamination, a study was conducted to assess arsenic load in rice ecosystem under deficit irrigation practices like intermittent ponding (IP), saturation (SAT) and aerobic (AER) imposed during stress allowable stage (16-40 days after transplanting) of the crop (genotype Shatabdi). Present survey showed that arsenic content in water and soil influenced the arsenic load of rice grain. Variation in arsenic among different water and soil samples influenced grain arsenic load to the maximum extent followed by straw. Deviation in root arsenic load due to variation in water and soil arsenic content was lowest. Arsenic concentration of grain is strongly related to the arsenic content of both irrigation water and soil. However, water has 10% higher impact on grain arsenic load over soil. Translocation of arsenic from root to shoot decreased with the increase in arsenic content of water. Imposition of saturated and aerobic environment reduced both yield and grain arsenic load. In contrast under IP a marked decrease in grain arsenic content recorded with insignificant reduction in yield. Deficit irrigation resulted in significant reduction (17.6-25%) in arsenic content of polished rice and the values were lower than that of the toxic level (<0.2 mg kg(-1)). In contrast the decrease in yield was to the tune of 0.9% under IP regime over CP. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Source term balance in a severe storm in the Southern North Sea

    Science.gov (United States)

    van Vledder, Gerbrant Ph.; Hulst, Sander Th. C.; McConochie, Jason D.

    2016-12-01

    This paper presents the results of a wave hindcast of a severe storm in the Southern North Sea to verify recently developed deep and shallow water source terms. The work was carried out in the framework of the ONR funded NOPP project (Tolman et al. 2013) in which deep and shallow water source terms were developed for use in third-generation wave prediction models. These deep water source terms for whitecapping, wind input and nonlinear interactions were developed, implemented and tested primarily in the WAVEWATCH III model, whereas shallow water source terms for depth-limited wave breaking and triad interactions were developed, implemented and tested primarily in the SWAN wave model. So far, the new deep-water source terms for whitecapping were not fully tested in shallow environments. Similarly, the shallow water source terms were not yet tested in large inter-mediate depth areas like the North Sea. As a first step in assessing the performance of these newly developed source terms, the source term balance and the effect of different physical settings on the prediction of wave heights and wave periods in the relatively shallow North Sea was analysed. The December 2013 storm was hindcast with a SWAN model implementation for the North Sea. Spectral wave boundary conditions were obtained from an Atlantic Ocean WAVEWATCH III model implementation and the model was driven by hourly CFSR wind fields. In the southern part of the North Sea, current and water level effects were included. The hindcast was performed with five different settings for whitecapping, viz. three Komen type whitecapping formulations, the saturation-based whitecapping by Van der Westhuysen et al. (2007) and the recently developed ST6 whitecapping as described by Zieger et al. (2015). Results of the wave hindcast were compared with buoy measurements at location K13 collected by the Dutch Ministry of Transport and Public Works. An analysis was made of the source term balance at three locations, the deep

  20. Source Term Model for Vortex Generator Vanes in a Navier-Stokes Computer Code

    Science.gov (United States)

    Waithe, Kenrick A.

    2004-01-01

    A source term model for an array of vortex generators was implemented into a non-proprietary Navier-Stokes computer code, OVERFLOW. The source term models the side force created by a vortex generator vane. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on the local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low profile vortex generator vane on a flat plate. In addition, the model was compared to experimental data of an S-duct with 22 co-rotating, low profile vortex generators. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator on a flat plate without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream-wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data. The peak vorticity and its location were also predicted very well when compared to numerical simulations and experimental data. The circulation predicted by the source term model matches the prediction of the numerical simulation. The source term model predicted the engine fan face distortion and total pressure recovery of the S-duct with 22 co-rotating vortex generators very well. The source term model allows a researcher to quickly investigate different locations of individual or a row of vortex generators. The researcher is able to conduct a preliminary investigation with minimal grid generation and computational time.

  1. Using Bayesian Belief Network (BBN) modelling for rapid source term prediction. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Dedda, F.D.; Hansson, F.; Sjoekvist, S.; Sunnegaerd, K. [Lloyd' s Register Consulting AB, Sundbyberg (Sweden)

    2013-10-15

    The project presented in this report deals with a number of complex issues related to the development of a tool for rapid source term prediction (RASTEP), based on a plant model represented as a Bayesian belief network (BBN) and a source term module which is used for assigning relevant source terms to BBN end states. Thus, RASTEP uses a BBN to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, composition, timing, and release path of released radio-nuclides). The output is a set of possible source terms with associated probabilities. One major issue has been associated with the integration of probabilistic and deterministic analyses are addressed, dealing with the challenge of making the source term determination flexible enough to give reliable and valid output throughout the accident scenario. The potential for connecting RASTEP to a fast running source term prediction code has been explored, as well as alternative ways of improving the deterministic connections of the tool. As part of the investigation, a comparison of two deterministic severe accident analysis codes has been performed. A second important task has been to develop a general method where experts' beliefs can be included in a systematic way when defining the conditional probability tables (CPTs) in the BBN. The proposed method includes expert judgement in a systematic way when defining the CPTs of a BBN. Using this iterative method results in a reliable BBN even though expert judgements, with their associated uncertainties, have been used. It also simplifies verification and validation of the considerable amounts of quantitative data included in a BBN. (Author)

  2. Quality of our groundwater resources: arsenic and fluoride

    Science.gov (United States)

    Nordstrom, D. Kirk

    2011-01-01

    Groundwater often contains arsenic or fluoride concentrations too high for drinking or cooking. These constituents, often naturally occurring, are not easy to remove. The right combination of natural or manmade conditions can lead to elevated arsenic or fluoride which includes continental source rocks, high alkalinity and pH, reducing conditions for arsenic, high phosphate, high temperature and high silica. Agencies responsible for safe drinking water should be aware of these conditions, be prepared to monitor, and treat if necessary.

  3. Acceptance and use of eight arsenic-safe drinking water options in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jennifer Inauen

    Full Text Available Arsenic contamination of drinking water is a serious public health threat. In Bangladesh, eight major safe water options provide an alternative to contaminated shallow tubewells: piped water supply, deep tubewells, pond sand filters, community arsenic-removal, household arsenic removal, dug wells, well-sharing, and rainwater harvesting. However, it is uncertain how well these options are accepted and used by the at-risk population. Based on the RANAS model (risk, attitudes, norms, ability, and self-regulation this study aimed to identify the acceptance and use of available safe water options. Cross-sectional face-to-face interviews were used to survey 1,268 households in Bangladesh in November 2009 (n = 872, and December 2010 (n = 396. The questionnaire assessed water consumption, acceptance factors from the RANAS model, and socioeconomic factors. Although all respondents had access to at least one arsenic-safe drinking water option, only 62.1% of participants were currently using these alternatives. The most regularly used options were household arsenic removal filters (92.9% and piped water supply (85.6%. However, the former result may be positively biased due to high refusal rates of household filter owners. The least used option was household rainwater harvesting (36.6%. Those who reported not using an arsenic-safe source differed in terms of numerous acceptance factors from those who reported using arsenic-safe sources: non-users were characterized by greater vulnerability; showed less preference for the taste and temperature of alternative sources; found collecting safe water quite time-consuming; had lower levels of social norms, self-efficacy, and coping planning; and demonstrated lower levels of commitment to collecting safe water. Acceptance was particularly high for piped water supplies and deep tubewells, whereas dug wells and well-sharing were the least accepted sources. Intervention strategies were derived from the results

  4. Cryptic exposure to arsenic.

    Science.gov (United States)

    Rossy, Kathleen M; Janusz, Christopher A; Schwartz, Robert A

    2005-01-01

    Arsenic is an odorless, colorless and tasteless element long linked with effects on the skin and viscera. Exposure to it may be cryptic. Although human intake can occur from four forms, elemental, inorganic (trivalent and pentavalent arsenic) and organic arsenic, the trivalent inorganic arsenicals constitute the major human hazard. Arsenic usually reaches the skin from occupational, therapeutic, or environmental exposure, although it still may be employed as a poison. Occupations involving new technologies are not exempt from arsenic exposure. Its acute and chronic effects are noteworthy. Treatment options exist for arsenic-induced pathology, but prevention of toxicity remains the main focus. Vitamin and mineral supplementation may play a role in the treatment of arsenic toxicity.

  5. Cryptic exposure to arsenic

    Directory of Open Access Journals (Sweden)

    Rossy Kathleen

    2005-01-01

    Full Text Available Arsenic is an odorless, colorless and tasteless element long linked with effects on the skin and viscera. Exposure to it may be cryptic. Although human intake can occur from four forms, elemental, inorganic (trivalent and pentavalent arsenic and organic arsenic, the trivalent inorganic arsenicals constitute the major human hazard. Arsenic usually reaches the skin from occupational, therapeutic, or environmental exposure, although it still may be employed as a poison. Occupations involving new technologies are not exempt from arsenic exposure. Its acute and chronic effects are noteworthy. Treatment options exist for arsenic-induced pathology, but prevention of toxicity remains the main focus. Vitamin and mineral supplementation may play a role in the treatment of arsenic toxicity.

  6. Fact Sheet on Arsenic

    Science.gov (United States)

    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.

  7. Arsenic Trioxide Injection

    Science.gov (United States)

    Arsenic trioxide is used to treat acute promyelocytic leukemia (APL; a type of cancer in which there ... worsened following treatment with other types of chemotherapy. Arsenic trioxide is in a class of medications called ...

  8. Arsenic exposure from drinking water, arsenic methylation capacity, and carotid intima-media thickness in Bangladesh.

    Science.gov (United States)

    Chen, Yu; Wu, Fen; Graziano, Joseph H; Parvez, Faruque; Liu, Mengling; Paul, Rina Rani; Shaheen, Ishrat; Sarwar, Golam; Ahmed, Alauddin; Islam, Tariqul; Slavkovich, Vesna; Rundek, Tatjana; Demmer, Ryan T; Desvarieux, Moise; Ahsan, Habibul

    2013-08-01

    We conducted a cross-sectional study to evaluate the interrelationships between past arsenic exposure, biomarkers specific for susceptibility to arsenic exposure, and carotid intima-media thickness (cIMT) in 959 subjects from the Health Effects of Arsenic Longitudinal Study in Bangladesh. We measured cIMT levels on average 7.2 years after baseline during 2010-2011. Arsenic exposure was measured in well water at baseline and in urine samples collected at baseline and during follow-up. Every 1-standard-deviation increase in urinary arsenic (357.9 µg/g creatinine) and well-water arsenic (102.0 µg/L) concentration was related to a 11.7-µm (95% confidence interval (CI): 1.8, 21.6) and 5.1-µm (95% CI: -0.2, 10.3) increase in cIMT, respectively. For every 10% increase in monomethylarsonic acid (MMA) percentage, there was an increase of 12.1 µm (95% CI: 0.4, 23.8) in cIMT. Among participants with a higher urinary MMA percentage, a higher ratio of urinary MMA to inorganic arsenic, and a lower ratio of dimethylarsinic acid to MMA, the association between well-water arsenic and cIMT was stronger. The findings indicate an effect of past long-term arsenic exposure on cIMT, which may be potentiated by suboptimal or incomplete arsenic methylation capacity. Future prospective studies are needed to confirm the association between arsenic methylation capacity and atherosclerosis-related outcomes.

  9. Literature review on metallic fuel source term for sodium cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Nam Duk; Bae, Moo Hoon; Shin, An Dong; Huh, Chang Wook [Korea Institute of Nuclear Safety, Daejon (Korea, Republic of)

    2012-10-15

    Source term is defined as the release of radionuclides from the fuel and coolant into the containment, and subsequently to the environment, following a severe accident where a significant portion of the reactor core has melted. Of the many issues associated with the development and deployment of SFRs, one of high regulatory importance is the source term to be used in the siting of the reactor. Apart from assessing the radiological consequences for siting, it is also important for designing filtering systems and even reactor components. Overly conservative source term for light water reactor, TID 14844 demands for very fast closure of main steam isolation valves, rapid startup of emergency diesels, and safety systems designed to mitigate gaseous iodine. In spite of this importance, most of the knowledge we have for SFR source term comes from the research performed before 1980s. Moreover, majority of the work on metallic fuels was done during the late 1950's through the 1960's. This paper reviews and summarizes the main characteristics of SFR source terms based on the available literatures.

  10. Evolution of community-based arsenic removal systems in remote villages in West Bengal, India: assessment of decade-long operation.

    Science.gov (United States)

    Sarkar, Sudipta; Greenleaf, John E; Gupta, Anirban; Ghosh, Debabrata; Blaney, Lee M; Bandyopadhyay, P; Biswas, R K; Dutta, Amal K; Sengupta, Arup K

    2010-11-01

    In Bangladesh and the neighboring state of West Bengal, India, over 100 million people are affected by widespread arsenic poisoning through drinking water drawn from underground sources containing arsenic at concentrations well above the permissible limit of 50 μg/L. The health effects caused by arsenic poisoning in this area is as catastrophic as any other natural calamity that occurred throughout the world in recent times. Since 1997, over 200 community level arsenic removal units have been installed in Indian subcontinent through collaboration between Bengal Engineering and Science University (BESU), India and Lehigh University, USA. Approximately 200,000 villagers collect arsenic-safe potable water from these units on a daily basis. The treated water is also safe for drinking with regard to its total dissolved solids, hardness, iron and manganese content. The units use regenerable arsenic-selective adsorbents. Regular maintenance and upkeep of the units is administered by the villagers through formation of villagers' water committee. The villagers contribute towards the cost of operation through collection of a small water tariff. Upon exhaustion, the adsorbents are regenerated in a central facility by a few trained villagers. The process of regeneration reduces the volume of disposable arsenic-laden solids by nearly two orders of magnitude and allows for the reuse of the adsorbent material. Finally, the arsenic-laden solids are contained on well-aerated coarse sand filters with minimum arsenic leaching. This disposal technique is scientifically more appropriate than dumping arsenic-loaded adsorbents in the reducing environment of landfills as currently practiced in developed countries including the United States. The design of the units underwent several modifications over last ten years to enhance the efficiency in terms of arsenic removal, ease of maintenance and ecologically safe containment and disposal of treatment residuals. The continued safe operation

  11. Atmospheric deposition of trace elements around point sources and human health risk assessment. II: Uptake of arsenic and chromium by vegetables grown near a wood preservation factory

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Moseholm, Lars; Nielsen, Margot M.

    1992-01-01

    Kale, lettuce, carrots and potatoes were grown in 20 experimental plots surrounding a wood preservation factory, to investigate the amount and pathways for plant uptake of arsenic and chromium. Arsenate used in the wood preservation process is converted to the more toxic arsenite by incineration...

  12. Bayesian estimation of a source term of radiation release with approximately known nuclide ratios

    Science.gov (United States)

    Tichý, Ondřej; Šmídl, Václav; Hofman, Radek

    2016-04-01

    We are concerned with estimation of a source term in case of an accidental release from a known location, e.g. a power plant. Usually, the source term of an accidental release of radiation comprises of a mixture of nuclide. The gamma dose rate measurements do not provide a direct information on the source term composition. However, physical properties of respective nuclide (deposition properties, decay half-life) can be used when uncertain information on nuclide ratios is available, e.g. from known reactor inventory. The proposed method is based on linear inverse model where the observation vector y arise as a linear combination y = Mx of a source-receptor-sensitivity (SRS) matrix M and the source term x. The task is to estimate the unknown source term x. The problem is ill-conditioned and further regularization is needed to obtain a reasonable solution. In this contribution, we assume that nuclide ratios of the release is known with some degree of uncertainty. This knowledge is used to form the prior covariance matrix of the source term x. Due to uncertainty in the ratios the diagonal elements of the covariance matrix are considered to be unknown. Positivity of the source term estimate is guaranteed by using multivariate truncated Gaussian distribution. Following Bayesian approach, we estimate all parameters of the model from the data so that y, M, and known ratios are the only inputs of the method. Since the inference of the model is intractable, we follow the Variational Bayes method yielding an iterative algorithm for estimation of all model parameters. Performance of the method is studied on simulated 6 hour power plant release where 3 nuclide are released and 2 nuclide ratios are approximately known. The comparison with method with unknown nuclide ratios will be given to prove the usefulness of the proposed approach. This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases

  13. 中药药源性砷中毒的护理分析%Nursing Analysis of Chinese Herbal Medicine Source of Arsenic Poisoning

    Institute of Scientific and Technical Information of China (English)

    陈丽丽

    2015-01-01

    目的:探讨中药源性砷中毒的临床护理体验及其效果。方法选择36例患者分为观察组与对照组,对观察组实施全面护理,对照组实施一般护理,统计两组患者的治疗前、后的尿砷结果。结果对照组尿砷结果显著优于对照组(<0.05)。结论对中药源性砷中毒患者实施积极有效的心理护理、饮食保健以及给药护理等全面护理措施,是降低尿砷结果,促进患者康复的有效方法。%Objective Discuss the clinical ef ect of nursing to traditional Chinese medicine-induced arsenic poisoning .Methods Thirty-six cases of patients were randomly selected and divided into experimental group and control group, the experimental group were implemented comprehensive care with this study, the control group were only used general nursing, then compare the value of urine arsenic of two groups in pretherapy and post-treatment. Results The value of urine arsenic of experimental group were bet er than that of the control group ( <0.05).Conclusion The ef ective comprehensive care to patients traditional Chinese medicine-induced arsenic poisoning such as psychological nursing , diet care and drug treatments could be the ef ective method to reduce the value of urine arsenic and promote patients recover.

  14. Finite Element Solutions for the Space Fractional Diffusion Equation with a Nonlinear Source Term

    Directory of Open Access Journals (Sweden)

    Y. J. Choi

    2012-01-01

    Full Text Available We consider finite element Galerkin solutions for the space fractional diffusion equation with a nonlinear source term. Existence, stability, and order of convergence of approximate solutions for the backward Euler fully discrete scheme have been discussed as well as for the semidiscrete scheme. The analytical convergent orders are obtained as O(k+hγ˜, where γ˜ is a constant depending on the order of fractional derivative. Numerical computations are presented, which confirm the theoretical results when the equation has a linear source term. When the equation has a nonlinear source term, numerical results show that the diffusivity depends on the order of fractional derivative as we expect.

  15. Analysis of safety information for nuclear power plants and development of source term estimation program

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Woon; Choi, Seong Soo; Park, Jin Hee [Atomic Creative Technology, Taejon (Korea, Republic of)

    1999-12-15

    Current CARE(Computerized Advisory System for Radiological Emergency) in KINS(Korea Institute of Nuclear Safety) has no STES(Source Term Estimation System) which links between SIDS(Safety Information Display System) and FADAS(Following Accident Dose Assessment System). So in this study, STES is under development. STES system is the system that estimates the source term based on the safety information provided by SIDS. Estimated source term is given to FADAS as an input for estimation of environmental effect of radiation. Through this first year project STES for the Kori 3,4 and Younggwang 1,2 has been developed. Since there is no CARE for Wolsong(PHWR) plants yet, CARE for Wolsong is under construction. The safety parameters are selected and the safety information display screens and the alarm logic for plant status change are developed for Wolsong Unit 2 based on the design documents for CANDU plants.

  16. Review of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O' Kula, K.R.; Hunter, C.H.

    1992-01-01

    The purpose of this work was to verify the Source Term Setup Module of the Reactor Accident Program (RAP) which is used to perform environmental consequence assessments during emergency response situations at the Savannah River Site (SRS). The Source Term Setup Module is that portion of the program that estimates the source term based on either an input number of melted assemblies or a derived number of melted assemblies based on the Total Stack Activity Monitor (TSAM) response. In order to verify the code, the following items were completed: a review of isotope and fuel specific data by examining the original literature, a complete derivation of all equations employed in the module, and a comparison study of hand calculations with computer results.

  17. Review of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O`Kula, K.R.; Hunter, C.H.

    1992-12-31

    The purpose of this work was to verify the Source Term Setup Module of the Reactor Accident Program (RAP) which is used to perform environmental consequence assessments during emergency response situations at the Savannah River Site (SRS). The Source Term Setup Module is that portion of the program that estimates the source term based on either an input number of melted assemblies or a derived number of melted assemblies based on the Total Stack Activity Monitor (TSAM) response. In order to verify the code, the following items were completed: a review of isotope and fuel specific data by examining the original literature, a complete derivation of all equations employed in the module, and a comparison study of hand calculations with computer results.

  18. Advanced Reactor PSA Methodologies for System Reliability Analysis and Source Term Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, D.; Brunett, A.; Passerini, S.; Grelle, A.; Bucknor, M.

    2017-06-26

    Beginning in 2015, a project was initiated to update and modernize the probabilistic safety assessment (PSA) of the GE-Hitachi PRISM sodium fast reactor. This project is a collaboration between GE-Hitachi and Argonne National Laboratory (Argonne), and funded in part by the U.S. Department of Energy. Specifically, the role of Argonne is to assess the reliability of passive safety systems, complete a mechanistic source term calculation, and provide component reliability estimates. The assessment of passive system reliability focused on the performance of the Reactor Vessel Auxiliary Cooling System (RVACS) and the inherent reactivity feedback mechanisms of the metal fuel core. The mechanistic source term assessment attempted to provide a sequence specific source term evaluation to quantify offsite consequences. Lastly, the reliability assessment focused on components specific to the sodium fast reactor, including electromagnetic pumps, intermediate heat exchangers, the steam generator, and sodium valves and piping.

  19. Modified Predictor-Corrector WAF Method for the Shallow Water Equations with Source Terms

    Directory of Open Access Journals (Sweden)

    Montri Maleewong

    2011-01-01

    Full Text Available A modified predictor-corrector scheme combining with the depth gradient method (DGM and the weighted average flux (WAF method has been presented to solve the one-dimensional shallow water equations with source terms. Approximate solutions in the predictor step are obtained by the DGM with piecewise-linear reconstructions in each cell volume. The source terms can then be calculated directly by these predicted values at the corresponding half-time step. In the corrector step, the TVD version of the WAF method is applied to calculate the numerical fluxes at the same half-time step for each cell face. The accuracy of numerical solutions is shown by applying the method to solve various test cases in both steady and unsteady problems with and without source terms. It shows that the numerical results are in good agreement with the existing analytical solutions as well as experimental data in some test cases.

  20. Source Term Analysis for Reactor Coolant System with Consideration of Fuel Burnup

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yu Jong; Ahn, Joon Gi; Hwang, Hae Ryong [KEPCO EnC, Daejeon (Korea, Republic of)

    2015-10-15

    The radiation source terms in reactor coolant system (RCS) of pressurized water reactor (PWR) are basic design information for ALARA design such as radiation protection and shielding. Usually engineering companies own self-developed computer codes to estimate the source terms in RCS. DAMSAM and FIPCO are the codes developed by engineering companies. KEPCO E and C has developed computer code, RadSTAR, for use in the Radiation Source Term Analysis for Reactor coolant system during normal operation. The characteristics of RadSTAR are as follows. (1) RadSTAR uses fuel inventory data calculated by ORIGEN, such as ORIGEN2 or ORIGEN-S to consider effects of the fuel burnup. (2) RadSTAR estimates fission products by using finite differential method and analytic method to minimize numerical error. (3) RadSTAR enhances flexibility by adding the function to build the nuclide data library (production pathway library) for user-defined nuclides from ORIGEN data library. (4) RadSTAR consists of two modules. RadSTAR-BL is to build the nuclide data library. RadSTAR-ST is to perform numerical analysis on source terms. This paper includes descriptions on the numerical model, the buildup of nuclide data library, and the sensitivity analysis and verification of RadSTAR. KEPCO E and C developed RadSTAR to calculate source terms in RCS during normal operation. Sensitivity analysis and accuracy verification showed that RadSTAR keeps stability at Δt of 0.1 day and gives more accurate results in comparison with DAMSAM. After development, RadSTAR will replace DAMSAM. The areas, necessary to further development of RadSTAR, are addition of source term calculations for activation products and for shutdown operation.

  1. Non-uniqueness of Admissible Weak Solutions to Compressible Euler Systems with Source Terms

    OpenAIRE

    Luo, Tianwen; Xie, Chunjing; Xin, Zhouping

    2015-01-01

    We consider admissible weak solutions to the compressible Euler system with source terms, which include rotating shallow water system and the Euler system with damping as special examples. In the case of anti-symmetric sources such as rotations, for general piecewise Lipschitz initial densities and some suitably constructed initial momentum, we obtain infinitely many global admissible weak solutions. Furthermore, we construct a class of finite-states admissible weak solutions to the Euler sys...

  2. A study of numerical methods for hyperbolic conservation laws with stiff source terms

    Science.gov (United States)

    Leveque, R. J.; Yee, H. C.

    1990-01-01

    In the present study of the behavior of typical numerical methods in the case of a model advection equation having a parameter-dependent source term, two approaches to the incorporation of the source terms are used: MacCormack-type predictor-corrector methods with flux limiters, and splitting methods in which the fluid dynamics and chemistry are handled in separate steps. The latter are found to perform slightly better. The model scalar equation is used to show that the incorrectness of the propagation speeds of discontinuities observed in the stiff case is due to the introduction of nonequilibrium values through numerical dissipation in the advection step.

  3. HTGR accident initiation and progression analysis status report. Volume V. AIPA fission product source terms

    Energy Technology Data Exchange (ETDEWEB)

    Alberstein, D.; Apperson, C.E. Jr.; Hanson, D.L.; Myers, B.F.; Pfeiffer, W.W.

    1976-02-01

    The primary objective of the Accident Initiation and Progression Analysis (AIPA) Program is to provide guidance for high-temperature gas-cooled reactor (HTGR) safety research and development. Among the parameters considered in estimating the uncertainties in site boundary doses are uncertainties in fission product source terms generated under normal operating conditions, i.e., fuel body inventories, circulating coolant activity, total plateout activity in the primary circuit, and plateout distributions. The volume presented documents the analyses of these source term uncertainties. The results are used for the detailed consequence evaluations, and they provide the basis for evaluation of fission products important for HTGR maintenance and shielding.

  4. The long-term problems of contaminated land: Sources, impacts and countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Baes, C.F. III

    1986-11-01

    This report examines the various sources of radiological land contamination; its extent; its impacts on man, agriculture, and the environment; countermeasures for mitigating exposures; radiological standards; alternatives for achieving land decontamination and cleanup; and possible alternatives for utilizing the land. The major potential sources of extensive long-term land contamination with radionuclides, in order of decreasing extent, are nuclear war, detonation of a single nuclear weapon (e.g., a terrorist act), serious reactor accidents, and nonfission nuclear weapons accidents that disperse the nuclear fuels (termed ''broken arrows'').

  5. Inhibition factors of arsenic trioxide therapeutic effects in patients with acute promyelocytic leukemia

    Institute of Scientific and Technical Information of China (English)

    Sui Meijuan; Zhang Zhuo; Zhou Jin

    2014-01-01

    Objective To summarize limitations involved in arsenic trioxide therapeutic effects in acute promyelocytic leukemia,because current studies show that some individuals of acute promyelocytic leukemia have relatively poor outcomes during treatment with arsenic trioxide.Data sources Most relevant articles were included in the PubMed database between 2000 and 2013 with the keywords "acute promyelocytic leukemia","arsenic trioxide","thiol" or "methylation".In addition,a few older articles were also reviewed.Study selection Data and articles related to arsenic trioxide effect in acute promyelocytic leukemia treatment were selected and reviewed.We developed an overview of limitations associated with arsenic trioxide therapeutic effect.Results This review focuses on the researches about the arsenic trioxide therapeutic effect in acute promyelocytic leukemia and summarizes three mainly limitations which can influence the arsenic trioxide therapeutic effect to different degrees.First,with the combination of arsenic and glutathione the therapeutic effect and cytotoxicity decrease when glutathione concentration increases; second,arsenic methylation,stable arsenic methylation products weaken the apoptosis effect of arsenic trioxide in leukemia cells; third,gene mutations affect the sensitivity of tumor cells to arsenic trioxide and increase the resistance of leukemia cells to arsenic trioxide.Conclusions The chief limitations are listed in the review.If we can exclude all of them,we can obtain a better therapeutic effect of arsenic trioxide in patients with acute promyelocytic leukemia.

  6. Second Order Fluid Glow Discharge Model Sustained by Different Source Terms%Second Order Fluid Glow Discharge Model Sustained by Different Source Terms

    Institute of Scientific and Technical Information of China (English)

    D. GUENDOUZ; A. HAMID; A. HENNAD

    2011-01-01

    Behavior of charged particles in a DC low pressure glow discharge is studied. The electric properties of the glow discharge in argon, maintained by a constant source term with uni- form electron and ion generation, between two plane electrodes or by secondary electron emission at the cathode, are determined. A fluid model is used to solve self-consistently the first three moments of the Boltzmann equation coupled with the Poisson equation. The stationary spatial distribution of the electron and ion densities, the electric potential, the electric field, and the electron energy, in a two-dimensional (2D) configuration, are presented.

  7. Refined Source Terms in WAVEWATCH III with Wave Breaking and Sea Spray Forecasts

    Science.gov (United States)

    2015-09-30

    shallow water outside the surf zone. After careful testing within a comprehensive suite of test bed cases, these refined source terms will be...including significant wave height, wave periods, wave train evolution, breaking wave probabilities, spectral crest length per unit area distributions...formulating the breaking strength b(k) in terms of the square root of the normalised saturation above a threshold, the Λ(k) values are obtained from

  8. Current status and prevention strategy for coal-arsenic poisoning in Guizhou, China.

    Science.gov (United States)

    Li, Dasheng; An, Dong; Zhou, Yunsu; Liu, Jie; Waalkes, Michael P

    2006-09-01

    Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnosed based on skin lesions and urinary arsenic excretion. Non-cancerous toxicities and malignancies were much more common and severe in these patients than in other arsenic-affected populations around the world. The high incidence of cancer and arsenic-related mortality in this cohort is alarming. Chelation therapy was performed but the long-term therapeutic effects are not satisfactory. The best prevention strategy is to eliminate arsenic exposure. Funds from the Chinese Government are currently available to solve this arsenic exposure problem. Strategies include the installation of vented stoves, the use of marsh gas to replace coal, health education, the improvement of nutritional status, and the use of various therapies to treat arsenic-induced skin and liver diseases.

  9. Current Status and Prevention Strategy for Coal-arsenic Poisoning in Guizhou, China

    Science.gov (United States)

    An, Dong; Zhou, Yunsu; Liu, Jie; Waalkes, Michael P.

    2006-01-01

    Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnosed based on skin lesions and urinary arsenic excretion. Non-cancerous toxicities and malignancies were much more common and severe in these patients than in other arsenic-affected populations around the world. The high incidence of cancer and arsenic-related mortality in this cohort is alarming. Chelation therapy was performed but the long-term therapeutic effects are not satisfactory. The best prevention strategy is to eliminate arsenic exposure. Funds from the Chinese Government are currently available to solve this arsenic exposure problem. Strategies include the installation of vented stoves, the use of marsh gas to replace coal, health education, the improvement of nutritional status, and the use of various therapies to treat arsenic-induced skin and liver diseases. PMID:17366768

  10. Using Reactive Transport Modeling to Evaluate the Source Term at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Y. Chen

    2001-12-19

    The conventional approach of source-term evaluation for performance assessment of nuclear waste repositories uses speciation-solubility modeling tools and assumes pure phases of radioelements control their solubility. This assumption may not reflect reality, as most radioelements (except for U) may not form their own pure phases. As a result, solubility limits predicted using the conventional approach are several orders of magnitude higher then the concentrations of radioelements measured in spent fuel dissolution experiments. This paper presents the author's attempt of using a non-conventional approach to evaluate source term of radionuclide release for Yucca Mountain. Based on the general reactive-transport code AREST-CT, a model for spent fuel dissolution and secondary phase precipitation has been constructed. The model accounts for both equilibrium and kinetic reactions. Its predictions have been compared against laboratory experiments and natural analogues. It is found that without calibrations, the simulated results match laboratory and field observations very well in many aspects. More important is the fact that no contradictions between them have been found. This provides confidence in the predictive power of the model. Based on the concept of Np incorporated into uranyl minerals, the model not only predicts a lower Np source-term than that given by conventional Np solubility models, but also produces results which are consistent with laboratory measurements and observations. Moreover, two hypotheses, whether Np enters tertiary uranyl minerals or not, have been tested by comparing model predictions against laboratory observations, the results favor the former. It is concluded that this non-conventional approach of source term evaluation not only eliminates over-conservatism in conventional solubility approach to some extent, but also gives a realistic representation of the system of interest, which is a prerequisite for truly understanding the long-term

  11. Arsenic cardiotoxicity: An overview.

    Science.gov (United States)

    Alamolhodaei, Nafiseh Sadat; Shirani, Kobra; Karimi, Gholamreza

    2015-11-01

    Arsenic, a naturally ubiquitous element, is found in foods and environment. Cardiac dysfunction is one of the major causes of morbidity and mortality in the world. Arsenic exposure is associated with various cardiopathologic effects including ischemia, arrhythmia and heart failure. Possible mechanisms of arsenic cardiotoxicity include oxidative stress, DNA fragmentation, apoptosis and functional changes of ion channels. Several evidences have shown that mitochondrial disruption, caspase activation, MAPK signaling and p53 are the pathways for arsenic induced apoptosis. Arsenic trioxide is an effective and potent antitumor agent used in patients with acute promyelocytic leukemia and produces dramatic remissions. As2O3 administration has major limitations such as T wave changes, QT prolongation and sudden death in humans. In this review, we discuss the underlying pathobiology of arsenic cardiotoxicity and provide information about cardiac health effects associated with some medicinal plants in arsenic toxicity.

  12. Arsenic removal from water

    Science.gov (United States)

    Moore, Robert C.; Anderson, D. Richard

    2007-07-24

    Methods for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical methods for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A method for continuous removal of arsenic from water is provided. Also provided is a method for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

  13. Arsenic poisoning in livestock.

    Science.gov (United States)

    el Bahri, L; Ben Romdane, S

    1991-06-01

    Arsenic is an important heavy metal intoxicant to livestock. Arsenical pesticides present significant hazards to animal health. The toxicity of arsenic varies with several factors--its chemical form, oxidation states, solubility. The phenylarsonic compounds are the least toxic and are used as feed additives in swine and poultry rations. However, roxarsone has a higher absolute toxicity than arsanilic acid. The mechanism of action is related to its reaction with sulfhydryl groups values to enzyme function and to its ability to uncouple oxydative phosphorylation. Most animals excrete arsenic quite readily. Toxicoses caused by inorganic and aliphatic organic arsenicals result in a different clinical syndrome than that from the phenylarsonic compounds. Arsenic poisoning may be confused with other types of intoxication. The specific antidote for inorganic arsenical poisoning is dimercaprol (BAL).

  14. The revival of the ancient drug-arsenic

    Institute of Scientific and Technical Information of China (English)

    黄晓军

    2003-01-01

    Arsenic, a natural substance, has been used as a traditional Chinese medicine for more than a thousand years. However, this medicine fell into disuse in the 1930s following the advent of radiotherapy and conventional cytotoxic drugs and reports about arsenic poisoning from its long-term low-dose ingestion. Until the late 1970s, it had its rebirth when a series of research papers from China described the successful application of AiLing-1,1 a traditional Chinese compound, containing arsenic trioxide (ATO) and other ingredients. Research into the molecular mechanisms of arsenic action has furthered clinical application of this drug.

  15. Poisoned Playgrounds: Arsenic in "Pressure-Treated" Wood.

    Science.gov (United States)

    Sharp, Renee; Walker, Bill

    This study of 180 pressure-treated wood samples shows that treated wood is a much greater source of arsenic exposure for children than arsenic-contaminated drinking water. The report determines that an average 5-year-old, playing less than 2 weeks on a chromated-copper-arsenate-treated (CCA) wood play set would exceed the lifetime cancer risk…

  16. Short-Term Memory Stages in Sign vs. Speech: The Source of the Serial Span Discrepancy

    Science.gov (United States)

    Hall, Matthew L.; Bavelier, Daphne

    2011-01-01

    Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory--perception, encoding, and recall--in this effect. The present study…

  17. Risk comparisons based on representative source terms with the NUREG-1150 results

    Energy Technology Data Exchange (ETDEWEB)

    Mubayi, V.; Davis, R.E.; Hanson, A.L.

    1993-12-01

    Standardized source terms, based on a specified release of fission products during potential accidents at commercial light water nuclear reactors, have been used for a long time for regulatory purposes. The siting of nuclear power plants, for example, which is governed by Part 100 of the Code of Federal Regulations Title 10, has utilized the source term recommended in TID-14844 supplemented by Regulatory Guides 1.3 and 1.4 and the Standard Review Plan. With the introduction of probabilistic risk assessment (PRA) methods, the source terms became characterized not only by the amount of fission products released, but also by the probability of the release. In the Reactor Safety Study, for example, several categories of source terms, characterized by release severity and probability, were developed for both pressurized and boiling water reactors (PWRs and BWRs). These categories were based on an understanding of the likely paths and associated phenomenology of accident progression following core damage to possible failure of the containment and release to the environment.

  18. Hölder-type approximation for the spatial source term of a backward heat equation

    DEFF Research Database (Denmark)

    Dang, Duc Trong; Mach, Minh Nguyet; Pham, Ngoc Dinh Alain;

    2010-01-01

    the function $\\varphi$ and the final temperature $g(x,y)$ are given approximately. The problem is severely ill-posed. Using an interpolation method and the truncated Fourier series, we construct a regularized solution for the source term $f(x,y)$. Our approximation gives the H\\"older-type error estimates...

  19. Short-Term Memory Stages in Sign vs. Speech: The Source of the Serial Span Discrepancy

    Science.gov (United States)

    Hall, Matthew L.; Bavelier, Daphne

    2011-01-01

    Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory--perception, encoding, and recall--in this effect. The present study…

  20. Enhancement of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O`Kula, K.R.; Taylor, R.P.; Kearnaghan, G.P.

    1992-12-31

    The purpose of this work is to use the results of the Savannah River Site K-Reactor Probabilistic Safety Assessment to determine the accident sequences and source terms for beyond design basis accidents. Additionally, the methodology necessary to allow the Reactor Accident Program to incorporate this information is to be discussed.

  1. Enhancement of the source term algorithm for emergency response at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, A.A.; O' Kula, K.R.; Taylor, R.P.; Kearnaghan, G.P.

    1992-01-01

    The purpose of this work is to use the results of the Savannah River Site K-Reactor Probabilistic Safety Assessment to determine the accident sequences and source terms for beyond design basis accidents. Additionally, the methodology necessary to allow the Reactor Accident Program to incorporate this information is to be discussed.

  2. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Science.gov (United States)

    2010-01-01

    ... AGRICULTURE LOANS AND GRANTS PRIMARILY FOR REAL ESTATE PURPOSES RURAL HOUSING LOANS AND GRANTS Rural Housing... 7 Agriculture 12 2010-01-01 2010-01-01 false Rates, terms, and source of funds. 1822.268 Section 1822.268 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING...

  3. POINTWISE AND UPWIND DISCRETIZATIONS OF SOURCE TERMS IN OPEN-CHANNEL FLOOD ROUTING

    Institute of Scientific and Technical Information of China (English)

    MENG Jian; CAO Zhi-xian; CARLING Paul A.

    2006-01-01

    Upwind algorithms are becoming progressively popular for river flood routing due to their capability of resolving trans-critical flow regimes. For consistency, these algorithms suggest natural upwind discretization of the source term, which may be essential for natural channels with irregular geometry. Yet applications of these upwind algorithms to natural river flows are rare, and in such applications the traditional and simpler pointwise, rather than upwind discretization of the source term is used. Within the framework of a first-order upwind algorithm, this paper presents a comparison of upwind and pointwise discretizations of the source term. Numerical simulations were carried out for a selected irregular channel comprising a pool-riffle sequence in the River Lune, England with observed data. It is shown that the impact of pointwise discretization, compared to the upwind, is appreciable mainly in flow zones with the Froude number closer to or larger than unity. The discrepancy due to pointwise and upwind discretizations of the source term is negligible in flow depth and hence in water surface elevation, but well manifested in mean velocity and derived flow quantities. Also the occurrence of flow reversal and equalisation over the pool-riffle sequence in response to increasing discharges is demonstrated.

  4. Severe accident source term characteristics for selected Peach Bottom sequences predicted by the MELCOR Code

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, J.J. [Oak Ridge National Lab., TN (United States)

    1993-09-01

    The purpose of this report is to compare in-containment source terms developed for NUREG-1159, which used the Source Term Code Package (STCP), with those generated by MELCOR to identify significant differences. For this comparison, two short-term depressurized station blackout sequences (with a dry cavity and with a flooded cavity) and a Loss-of-Coolant Accident (LOCA) concurrent with complete loss of the Emergency Core Cooling System (ECCS) were analyzed for the Peach Bottom Atomic Power Station (a BWR-4 with a Mark I containment). The results indicate that for the sequences analyzed, the two codes predict similar total in-containment release fractions for each of the element groups. However, the MELCOR/CORBH Package predicts significantly longer times for vessel failure and reduced energy of the released material for the station blackout sequences (when compared to the STCP results). MELCOR also calculated smaller releases into the environment than STCP for the station blackout sequences.

  5. Regulatory Technology Development Plan - Sodium Fast Reactor: Mechanistic Source Term – Trial Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brunett, Acacia J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Denman, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nuclear Engineering Division; Clark, Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nuclear Engineering Division; Denning, Richard S. [Consultant, Columbus, OH (United States)

    2016-10-01

    The potential release of radioactive material during a plant incident, referred to as the source term, is a vital design metric and will be a major focus of advanced reactor licensing. The U.S. Nuclear Regulatory Commission has stated an expectation for advanced reactor vendors to present a mechanistic assessment of the potential source term in their license applications. The mechanistic source term presents an opportunity for vendors to realistically assess the radiological consequences of an incident and may allow reduced emergency planning zones and smaller plant sites. However, the development of a mechanistic source term for advanced reactors is not without challenges, as there are often numerous phenomena impacting the transportation and retention of radionuclides. This project sought to evaluate U.S. capabilities regarding the mechanistic assessment of radionuclide release from core damage incidents at metal fueled, pool-type sodium fast reactors (SFRs). The purpose of the analysis was to identify, and prioritize, any gaps regarding computational tools or data necessary for the modeling of radionuclide transport and retention phenomena. To accomplish this task, a parallel-path analysis approach was utilized, as shown below. One path, led by Argonne and Sandia National Laboratories, sought to perform a mechanistic source term assessment using available codes, data, and models, with the goal to identify gaps in the current knowledge base. The second path, performed by an independent contractor, performed sensitivity analyses to determine the importance of particular radionuclides and transport phenomena in regards to offsite consequences. The results of the two pathways were combined to prioritize gaps in current capabilities.

  6. Low-level radioactive waste source terms for the 1992 integrated data base

    Energy Technology Data Exchange (ETDEWEB)

    Loghry, S L; Kibbey, A H; Godbee, H W; Icenhour, A S; DePaoli, S M

    1995-01-01

    This technical manual presents updated generic source terms (i.e., unitized amounts and radionuclide compositions) which have been developed for use in the Integrated Data Base (IDB) Program of the U.S. Department of Energy (DOE). These source terms were used in the IDB annual report, Integrated Data Base for 1992: Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 8, October 1992. They are useful as a basis for projecting future amounts (volume and radioactivity) of low-level radioactive waste (LLW) shipped for disposal at commercial burial grounds or sent for storage at DOE solid-waste sites. Commercial fuel cycle LLW categories include boiling-water reactor, pressurized-water reactor, fuel fabrication, and uranium hexafluoride (UF{sub 6}) conversion. Commercial nonfuel cycle LLW includes institutional/industrial (I/I) waste. The LLW from DOE operations is category as uranium/thorium fission product, induced activity, tritium, alpha, and {open_quotes}other{close_quotes}. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF{sub 6} conversion, which is normalized on the basis of heavy metal requirement [metric tons of initial heavy metal ]. The nonfuel cycle commercial LLW source term is normalized on the basis of volume (cubic meters) and radioactivity (curies) for each subclass within the I/I category. The DOE LLW is normalized in a manner similar to that for commercial I/I waste. The revised source terms are based on the best available historical data through 1992.

  7. Fusion of chemical, biological, and meteorological observations for agent source term estimation and hazard refinement

    Science.gov (United States)

    Bieringer, Paul E.; Rodriguez, Luna M.; Sykes, Ian; Hurst, Jonathan; Vandenberghe, Francois; Weil, Jeffrey; Bieberbach, George, Jr.; Parker, Steve; Cabell, Ryan

    2011-05-01

    Chemical and biological (CB) agent detection and effective use of these observations in hazard assessment models are key elements of our nation's CB defense program that seeks to ensure that Department of Defense (DoD) operations are minimally affected by a CB attack. Accurate hazard assessments rely heavily on the source term parameters necessary to characterize the release in the transport and dispersion (T&D) simulation. Unfortunately, these source parameters are often not known and based on rudimentary assumptions. In this presentation we describe an algorithm that utilizes variational data assimilation techniques to fuse CB and meteorological observations to characterize agent release source parameters and provide a refined hazard assessment. The underlying algorithm consists of a combination of modeling systems, including the Second order Closure Integrated PUFF model (SCIPUFF), its corresponding Source Term Estimation (STE) model, a hybrid Lagrangian-Eulerian Plume Model (LEPM), its formal adjoint, and the software infrastructure necessary to link them. SCIPUFF and its STE model are used to calculate a "first guess" source estimate. The LEPM and corresponding adjoint are then used to iteratively refine this release source estimate using variational data assimilation techniques. This algorithm has undergone preliminary testing using virtual "single realization" plume release data sets from the Virtual THreat Response Emulation and Analysis Testbed (VTHREAT) and data from the FUSION Field Trials 2007 (FFT07). The end-to-end prototype of this system that has been developed to illustrate its use within the United States (US) Joint Effects Model (JEM) will be demonstrated.

  8. A Systematic Search for Short-term Variability of EGRET Sources

    Science.gov (United States)

    Wallace, P. M.; Griffis, N. J.; Bertsch, D. L.; Hartman, R. C.; Thompson, D. J.; Kniffen, D. A.; Bloom, S. D.

    2000-01-01

    The 3rd EGRET Catalog of High-energy Gamma-ray Sources contains 170 unidentified sources, and there is great interest in the nature of these sources. One means of determining source class is the study of flux variability on time scales of days; pulsars are believed to be stable on these time scales while blazers are known to be highly variable. In addition, previous work has demonstrated that 3EG J0241-6103 and 3EG J1837-0606 are candidates for a new gamma-ray source class. These sources near the Galactic plane display transient behavior but cannot be associated with any known blazers. Although, many instances of flaring AGN have been reported, the EGRET database has not been systematically searched for occurrences of short-timescale (approximately 1 day) variability. These considerations have led us to conduct a systematic search for short-term variability in EGRET data, covering all viewing periods through proposal cycle 4. Six 3EG catalog sources are reported here to display variability on short time scales; four of them are unidentified. In addition, three non-catalog variable sources are discussed.

  9. Identification and quantification of phytochelatins in roots of rice to long-term exposure: evidence of individual role on arsenic accumulation and translocation.

    Science.gov (United States)

    Batista, Bruno Lemos; Nigar, Meher; Mestrot, Adrien; Rocha, Bruno Alves; Barbosa Júnior, Fernando; Price, Adam H; Raab, Andrea; Feldmann, Jörg

    2014-04-01

    Rice has the predilection to take up arsenic in the form of methylated arsenic (o-As) and inorganic arsenic species (i-As). Plants defend themselves using i-As efflux systems and the production of phytochelatins (PCs) to complex i-As. Our study focused on the identification and quantification of phytochelatins by HPLC-ICP-MS/ESI-MS, relating them to the several variables linked to As exposure. GSH, 11 PCs, and As-PC complexes from the roots of six rice cultivars (Italica Carolina, Dom Sofid, 9524, Kitrana 508, YRL-1, and Lemont) exposed to low and high levels of i-As were compared with total, i-As, and o-As in roots, shoots, and grains. Only Dom Sofid, Kitrana 508, and 9524 were found to produce higher levels of PCs even when exposed to low levels of As. PCs were only correlated to i-As in the roots (r=0.884, P <0.001). However, significant negative correlations to As transfer factors (TF) roots-grains (r= -0.739, P <0.05) and shoots-grains (r= -0.541, P <0.05), suggested that these peptides help in trapping i-As but not o-As in the roots, reducing grains' i-As. Italica Carolina reduced i-As in grains after high exposure, where some specific PCs had a special role in this reduction. In Lemont, exposure to elevated levels of i-As did not result in higher i-As levels in the grains and there were no significant increases in PCs or thiols. Finally, the high production of PCs in Kitrana 508 and Dom Sofid in response to high As treatment did not relate to a reduction of i-As in grains, suggesting that other mechanisms such as As-PC release and transport seems to be important in determining grain As in these cultivars.

  10. Cancer excess after arsenic exposure from contaminated milk powder

    DEFF Research Database (Denmark)

    Yorifuji, Takashi; Tsuda, Toshihide; Doi, Hiroyuki

    2011-01-01

    Long-term exposure to inorganic arsenic is related to increased risk of cancer in the lung, skin, bladder, and, possibly, other sites. However, little is known about the consequences of developmental exposures in regard to cancer risk. During early summer in 1955, mass arsenic poisoning of infants...

  11. Toxic substances in surface waters and sediments--A study to assess the effects of arsenic-contaminated alluvial sediment in Whitewood Creek, South Dakota

    Science.gov (United States)

    Kuwabara, James S.; Fuller, Christopher C.

    2003-01-01

    Field measurements and bioassay experiments were done to investigate the effects of arsenic and phosphorus interactions on sorption of these solutes by the benthic flora (periphyton and submerged macrophytes) in Whitewood Creek, a stream in western South Dakota. Short-term (24-hour) sorption experiments were used to determine arsenic transport characteristics for algae (first-order rate constants for solute sorption, biomass, and accumulation factors) collected in the creek along a transect beginning upstream from a mine discharge point and downgradient through a 57-kilometer reach. Temporal changes in biomass differed significantly between and within sampling sites. Arsenic concentrations in plant tissue increased with distance downstream, but temporal changes in concentrations in tissues differed considerably from site to site. Cultures of Achnanthes minutissima (Bacillariophyceae) and Stichococcus sp. (Chlorophyceae) were isolated from four sites along a longitudinal concentration gradient of dissolved arsenic within the study reach and were maintained at ambient solute concentrations. Arsenic accumulation factors and sorption-rate constants for these isolates were determined as a function of dissolved arsenate and orthophosphate. Cell surfaces of algal isolates exhibited preferential orthophosphate sorption over arsenate. Initial sorption of both arsenate and orthophosphate followed first-order mass transfer for each culturing condition. Although sorption-rate constants increased slightly with increased dissolved-arsenate concentration, algae, isolated from a site with elevated dissolved arsenic in the stream channel, had a significantly slower rate of arsenic sorption compared with the same species isolated from an uncontaminated site upstream. In diel studies, amplitudes of the pH cycles increased with measured biomass except at a site immediately downstream from water-treatment-plant discharge. Inorganic pentavalent arsenic dominated arsenic speciation at

  12. Search for correlated radio and optical events in long-term studies of extragalactic sources

    Science.gov (United States)

    Pomphrey, R. B.; Smith, A. G.; Leacock, R. J.; Olsson, C. N.; Scott, R. L.; Pollock, J. T.; Edwards, P.; Dent, W. A.

    1976-01-01

    For the first time, long-term records of radio and optical fluxes of a large sample of variable extragalactic sources have been assembled and compared, with linear cross-correlation analysis being used to reinforce the visual comparisons. Only in the case of the BL Lac object OJ 287 is the correlation between radio and optical records strong. In the majority of cases there is no evidence of significant correlation, although nine sources show limited or weak evidence of correlation. The results do not support naive extrapolation of the expanding source model. The general absence of strong correlation between the radio and optical regions has important implications for the energetics of events occurring in such sources.

  13. Arsenic loads in Spearfish Creek, western South Dakota, water years 1989-91

    Science.gov (United States)

    Driscoll, Daniel G.; Hayes, Timothy S.

    1995-01-01

    Numerous small tributaries on the eastern flank of Spearfish Creek originate within a mineralized area with a long history of gold-mining activity. Some streams draining this area are known to have elevated concentrations of arsenic. One such tributary is Annie Creek, where arsenic concentrations regularly approach the Maximum Contaminant Level of 50 mg/L (micrograms per liter) established by the U.S. Environmental Protection Agency. A site on Annie Creek was proposed for inclusion on the National Priorities List by the Environmental Protection Agency in 1991. This report presents information about arsenic loads and concentrations in Spearfish Creek and its tributaries, including Annie Creek. Stream types were classified according to geologic characteris- tics and in-stream arsenic concentrations. The first type includes streams that lack significant arsenic sources and have low in-stream arsenic concentra- tions. The second type has abundant arsenic sources and high in-stream concentrations. The third type has abundant arsenic sources but only moderate in-stream concentrations. The fourth type is a mixture of the first three types. Annual loads of dissolved arsenic were calculated for two reaches of Spearfish Creek to quantify arsenic loads at selected gaging stations during water years 1989-91. Mass-balance calculations also were performed to estimate arsenic concentrations for ungaged inflows to Spearfish Creek. The drainage area of the upstream reach includes significant mineralized areas, whereas the drainage area of the downstream reach generally is without known arsenic sources. The average load of dissolved arsenic transported from the upstream reach of Spearfish Creek, which is representative of a type 4 stream, was 158 kilograms per year, calculated for station 06430900, Spearfish Creek above Spearfish. Gaged headwater tributaries draining unmineralized areas (type 1) contributed only 16 percent of the arsenic load in 63 percent of the discharge. Annie

  14. Inventory and source term evaluation of Russian nuclear power plants for marine applications

    Energy Technology Data Exchange (ETDEWEB)

    Reistad, O. [Norwegian Radiation Protection Authority (Norway); Oelgaard, P.L. [Risoe National Lab. (Denmark)

    2006-04-15

    This report discusses inventory and source term properties in regard to operation and possible releases due to accidents from Russian marine reactor systems. The first part of the report discusses relevant accidents on the basis of both Russian and western sources. The overview shows that certain vessels were much more accident prone compared to others, in addition, there have been a noteworthy reduction in accidents the last two decades. However, during the last years new types of incidents, such as collisions, has occurred more frequently. The second part of the study considers in detail the most important factors for the source term; reactor operational characteristics and the radionuclide inventory. While Russian icebreakers has been operated on a similar basis as commercial power plants, the submarines has different power cyclograms which results in considerable lower values for fission product inventory. Theoretical values for radionuclide inventory are compared with computed results using the modelling tool HELIOS. Regarding inventory of transuranic elements, the results of the calculations are discussed in detail for selected vessels. Criticality accidents, loss-of-cooling accidents and sinking accidents are considered, bases on actual experiences with these types of accident and on theoretical considerations, and source terms for these accidents are discussed in the last chapter. (au)

  15. Biogeochemical controls of arsenic occurrence and mobility in the Indian Sundarban mangrove ecosystem.

    Science.gov (United States)

    Mandal, S K; Dey, Mitali; Ganguly, D; Sen, S; Jana, T K

    2009-05-01

    This study aims to investigate the control of arsenic distribution by biogeochemical processes in the Indian Sundarban mangrove ecosystem and the importance of this ecosystem as an arsenic source for surrounding coastal water. The As(V)/As(III) ratio was found to be significantly lower in both surface and pore waters compared to sea water, which could be attributed to biogeochemical interconversion of these arsenic forms. The biological uptake of arsenic due to primary and benthic production occurs during the post-monsoon season, and is followed by the release of arsenic during the biochemical degradation and dissolution of plankton in the pre-monsoon season. These results suggest that arsenic is immobilized during incorporation into the arsenic-bearing initial phase, and unlikely to be released into pore water until the complete microbial degradation of arsenic-bearing organic compounds.

  16. A Methodology for a Comprehensive Probabilistic Tsunami Hazard Assessment: Multiple Sources and Short-Term Interactions

    Directory of Open Access Journals (Sweden)

    Grezio Anita

    2015-01-01

    Full Text Available We propose a methodological approach for a comprehensive and total probabilistic tsunami hazard assessment (TotPTHA, in which many different possible source types concur to the definition of the total tsunami hazard at given target sites. In a multi-hazard and multi-risk perspective, the approach allows us to consider all possible tsunamigenic sources (seismic events, slides, volcanic eruptions, asteroids, etc.. In this respect, we also formally introduce and discuss the treatment of interaction/cascade effects in the TotPTHA analysis and we demonstrate how the triggering events may induce significant temporary variations in short-term analysis of the tsunami hazard. In two target sites (the city of Naples and the island of Ischia in Italy we prove the feasibility of the TotPTHA methodology in the multi—source case considering near submarine seismic sources and submarine mass failures in the study area. The TotPTHA indicated that the tsunami hazard increases significantly by considering both the potential submarine mass failures and the submarine seismic events. Finally, the importance of the source interactions is evaluated by applying a triggering seismic event that causes relevant changes in the short-term TotPTHA.

  17. The impacts of different long-term fertilization regimes on the bioavailability of arsenic in soil: integrating chemical approach with Escherichia coli arsRp::luc-based biosensor.

    Science.gov (United States)

    Hou, Qi-Hui; Ma, An-Zhou; Lv, Di; Bai, Zhi-Hui; Zhuang, Xu-Liang; Zhuang, Guo-Qiang

    2014-07-01

    An Escherichia coli arsRp::luc-based biosensor was constructed to measure the bioavailability of arsenic (As) in soil. In previous induction experiments, it produced a linear response (R (2) = 0.96, P bioavailability of arsenic (As) in soil. Per the BCR-SEPs analysis, the application of M and M + NPK led to a significant (P bioavailable As in manure-fertilized (M and M + NPK) soil was significantly higher (P bioavailable As. More significantly, E. coli biosensor-determined As was only 18.46-85.17 % of exchangeable As and 20.68-90.1 % of reducible As based on BCR-SEPs. In conclusion, NKP fertilization was recommended as a more suitable regime in As-polluted soil especially with high As concentration, and this E. coli arsRp::luc-based biosensor was a more realistic approach in assessing the bioavailability of As in soil since it would not overrate the risk of As to the environment.

  18. Outcome analysis of screening on high arsenic water source in Jingzhou City, Hubei Province%湖北省荆州市高砷水源筛查结果分析

    Institute of Scientific and Technical Information of China (English)

    袁梅枝; 胡于泽; 王加松; 李斌; 付正银; 董娟; 彭孝武

    2009-01-01

    Objective To survey the arsenic content of drinking water in Jingzhou City, to provide basis for prevention and control of endemic arsenic disease. Methods According to historical data, the .arsenic content of water was detected in 357 villages from 6 counties of Jianglin, Songzi, Gongan, Shishou, Jianli, Honghushi in Jinzhou City in 2007 and 2008, The past have been found to have high arsenic water villages, villages known to have high concentration of arsenic were put into census. Villages not found to have high-arsenic wells were sampled 10 percent of the whole water resources at five directions of east, west, south, north and the center. Using sampling investigation, water arsenic was determined by half -quantitative fast reagent kit. All samples of water with arsenic exceeding the standard were re-determined using silver diethyl dithiocarbamate using silver diethyl dithiocarbamate colorimetric mothod. Survey on the disease was carried out in the villages with arsenic exeeeding the standard. Results All 6074 water samples was inspected. Arsenic in 210 samples outnumbered 0.05 mg/L, 51 natural villages were high arsenic areas;The maximum level of arsenic content in drinking water was 0.7 mg/L 3.2% (152/4784) of the wells no deeper that 30 meters and 4.9%(58/1184) between 30 to 100 m had arsenic exceeding the standard The water arsenic content was normal when the wells was deeper that 100 m. The abnormal percentages of water arsenic was related with the depth of wells with a significant difference(χ2 = 12.29,P 100 m的水井水砷超标率为0,不同井深水井水砷超标率组间比较,差异有统计学意义(χ2=12.29,P100 m.

  19. Atmospheric arsenic and lead emissions from primary anthropogenic sources and related analytical inventory models%重点源大气砷铅污染排放模型及特征

    Institute of Scientific and Technical Information of China (English)

    吴文俊; 蒋洪强

    2011-01-01

    Recently, atmospheric arsenic and lead as the unconventional pollutants have become an increasingly important concern in China. The study summarizes the contribution of anthropogenic sources to atmospheric heavy metals emissions both in China and abroad. The results show that China is one of the countries that have the most emissions of atmospheric heavy metals from anthropogenic sources in the world, and the coal combustion and nonferrous metallurgical industry would be the primary and most important anthropogenic source of heavy metal emissions in a relatively long period of time. Based on the systematic survey on the resources and industrial distribution of the coal burning and non-ferrous metallurgical industry, the analytical inventory models related to China's atmospheric heavy metal emissions were constructed and atmospheric arsenic and lead emissions inventory of the major sources was analyzed. The results could be summarized as follows: (1) From 2000 to 2008, arsenic and lead emissions from coal combustion were 93733t with mean annual increasing rate of 7.93%, and 18836t from non-ferrous metals smelting during the period of 2004 to 2008 with mean annual increase of 15.2%; (2) during 2000 to 2008, the atmospheric arsenic and lead emissions fromcoal-fired power plants were largest among all economic sectors, accounting for 44.6% to 57.1% of the total and showing a trend of annual increasing; (3) Shanx、Hebe、Henan and Hunan provinces were big emitters. The atmospheric arsenic and lead emission from coal combustion is mainly concentrated in China's northern and mid-eastern provinces including Shanx、 Shandong、Hebei、 Henan and Jiangsu provinces which are populous areas with concentrated industries and rapid economic development, accounting for 39.1% of the total emissions from coal combustion. The atmospheric arsenic and lead emissions from nonferrous metallurgical industry is mainly concentrated in Henan and Hunan provinces where nonferrous

  20. The global menace of arsenic and its conventional remediation - A critical review.

    Science.gov (United States)

    Sarkar, Arpan; Paul, Biswajit

    2016-09-01

    Arsenic is a ubiquitous element found in the earth crust with a varying concentration in the earth soil and water. Arsenic has always been under the scanner due to its toxicity in human beings. Contamination of arsenic in drinking water, which generally finds its source from arsenic-containing aquifers; has severely threatened billions of people all over the world. Arsenic poisoning is worse in Bangladesh where As(III) is abundant in waters of tube wells. Natural occurrence of arsenic in groundwater could result from both, oxidative and reductive dissolution. Geothermally heated water has the potential to liberate arsenic from surrounding rocks. Inorganic arsenic has been found to have more toxicity than the organic forms of arsenic. MMA and DMA are now been considered as the organic arsenic compounds having the potential to impair DNA and that is why MMA and DMA are considered as carcinogens. Endless efforts of researchers have elucidated the source, behavior of arsenic in various parts of the environment, mechanism of toxicity and various remediation processes; although, there are lots of areas still to be addressed. In this article, attempts have been made to lay bare an overview of geochemistry, toxicity and current removal techniques of arsenic together.

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

    OpenAIRE

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

    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...

  2. Assessing arsenic exposure in households using bottled water or point-of-use treatment systems to mitigate well water contamination.

    Science.gov (United States)

    Smith, Andrew E; Lincoln, Rebecca A; Paulu, Chris; Simones, Thomas L; Caldwell, Kathleen L; Jones, Robert L; Backer, Lorraine C

    2016-02-15

    There is little published literature on the efficacy of strategies to reduce exposure to residential well water arsenic. The objectives of our study were to: 1) determine if water arsenic remained a significant exposure source in households using bottled water or point-of-use treatment systems; and 2) evaluate the major sources and routes of any remaining arsenic exposure. We conducted a cross-sectional study of 167 households in Maine using one of these two strategies to prevent exposure to arsenic. Most households included one adult and at least one child. Untreated well water arsenic concentrations ranged from arsenic and untreated well water arsenic concentration, while accounting for documented consumption of untreated water and dietary sources. If mitigation strategies were fully effective, there should be no relationship between urinary arsenic and well water arsenic. To the contrary, we found that untreated arsenic water concentration remained a significant (p ≤ 0.001) predictor of urinary arsenic levels. When untreated water arsenic concentrations were arsenic was no longer a significant predictor of urinary arsenic. Time spent bathing (alone or in combination with water arsenic concentration) was not associated with urinary arsenic. A predictive analysis of the average study participant suggested that when untreated water arsenic ranged from 100 to 500 μg/L, elimination of any untreated water use would result in an 8%-32% reduction in urinary arsenic for young children, and a 14%-59% reduction for adults. These results demonstrate the importance of complying with a point-of-use or bottled water exposure reduction strategy. However, there remained unexplained, water-related routes of exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. On the application of subcell resolution to conservation laws with stiff source terms

    Science.gov (United States)

    Chang, Shih-Hung

    1989-01-01

    LeVeque and Yee recently investigated a one-dimensional scalar conservation law with stiff source terms modeling the reacting flow problems and discovered that for the very stiff case most of the current finite difference methods developed for non-reacting flows would produce wrong solutions when there is a propagating discontinuity. A numerical scheme, essentially nonoscillatory/subcell resolution - characteristic direction (ENO/SRCD), is proposed for solving conservation laws with stiff source terms. This scheme is a modification of Harten's ENO scheme with subcell resolution, ENO/SR. The locations of the discontinuities and the characteristic directions are essential in the design. Strang's time-splitting method is used and time evolutions are done by advancing along the characteristics. Numerical experiment using this scheme shows excellent results on the model problem of LeVeque and Yee. Comparisons of the results of ENO, ENO/SR, and ENO/SRCD are also presented.

  4. In-plant source term measurements at Fort Calhoun Station - Unit 1. Topical technical report

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, N.C.; Keller, J.H.; Bunting, R.L.; Motes, B.G.; Croney, S.T.

    1978-07-01

    Data obtained from an in-plant source term measurement program are presented. The objective of this program is to provide operational data that can be used in the generic evaluation of plant system design in the licensing process and for updating of the calculational models used by the NRC staff in their evaluation of radioactive waste management systems for operating pressurized water reactors. A data base is provided for radioisotope inventory in plant systems, radioactive waste management system performance, and source terms for both liquid and gaseous systems. Data presented were obtained at the Fort Calhoun Station - Unit 1, operated by the Omaha Public Power District (OPPD), located at Blair, Nebraska. In-plant measurements were conducted during the time period from August, 1976 through February 1977. This plant is the first of a planned series of six (6) operating PWR's to be studied.

  5. New Source Term Model for the RESRAD-OFFSITE Code Version 3

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Charley [Argonne National Lab. (ANL), Argonne, IL (United States); Gnanapragasam, Emmanuel [Argonne National Lab. (ANL), Argonne, IL (United States); Cheng, Jing-Jy [Argonne National Lab. (ANL), Argonne, IL (United States); Kamboj, Sunita [Argonne National Lab. (ANL), Argonne, IL (United States); Chen, Shih-Yew [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-06-01

    This report documents the new source term model developed and implemented in Version 3 of the RESRAD-OFFSITE code. This new source term model includes: (1) "first order release with transport" option, in which the release of the radionuclide is proportional to the inventory in the primary contamination and the user-specified leach rate is the proportionality constant, (2) "equilibrium desorption release" option, in which the user specifies the distribution coefficient which quantifies the partitioning of the radionuclide between the solid and aqueous phases, and (3) "uniform release" option, in which the radionuclides are released from a constant fraction of the initially contaminated material during each time interval and the user specifies the duration over which the radionuclides are released.

  6. Binary Source Microlensing Event OGLE-2016-BLG-0733: Interpretation of a Long-Term Asymmetric Perturbation

    Science.gov (United States)

    Jung, Y. K.; Udalski, A.; Yee, J. C.; Sumi, T.; Gould, A.; Han, C.; Albrow, M. D.; Lee, C.-U.; Bennett, D. P.; Suzuki, D.

    2017-01-01

    In the process of analyzing an observed light curve, one often confronts various scenarios that can mimic the planetary signals causing difficulties in the accurate interpretation of the lens system. In this paper, we present the analysis of the microlensing event OGLE-2016-BLG-0733. The light curve of the event shows a long-term asymmetric perturbation that would appear to be due to a planet. From the detailed modeling of the lensing light curve, however, we find that the perturbation originates from the binarity of the source rather than the lens. This result demonstrates that binary sources with roughly equal-luminosity components can mimic long-term perturbations induced by planets with projected separations near the Einstein ring. The result also represents the importance of the consideration of various interpretations in planet-like perturbations and of high-cadence observations for ensuring the unambiguous detection of the planet.

  7. Source terms for analysis of accidents at a high level waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Mubayi, V.; Davis, R.E.; Youngblood, R.

    1989-01-01

    This paper describes an approach to identifying source terms from possible accidents during the preclosure phase of a high-level nuclear waste repository. A review of the literature on repository safety analyses indicated that source term estimation is in a preliminary stage, largely based on judgement-based scoping analyses. The approach developed here was to partition the accident space into domains defined by certain threshold values of temperature and impact energy density which may arise in potential accidents and specify release fractions of various radionuclides, present in the waste form, in each domain. Along with a more quantitative understanding of accident phenomenology, this approach should help in achieving a clearer perspective on scenarios important to preclosure safety assessments of geologic repositories. 18 refs., 3 tabs.

  8. Piecewise Approximate Analytical Solutions of High-Order Singular Perturbation Problems with a Discontinuous Source Term

    Directory of Open Access Journals (Sweden)

    Essam R. El-Zahar

    2016-01-01

    Full Text Available A reliable algorithm is presented to develop piecewise approximate analytical solutions of third- and fourth-order convection diffusion singular perturbation problems with a discontinuous source term. The algorithm is based on an asymptotic expansion approximation and Differential Transform Method (DTM. First, the original problem is transformed into a weakly coupled system of ODEs and a zero-order asymptotic expansion of the solution is constructed. Then a piecewise smooth solution of the terminal value reduced system is obtained by using DTM and imposing the continuity and smoothness conditions. The error estimate of the method is presented. The results show that the method is a reliable and convenient asymptotic semianalytical numerical method for treating high-order singular perturbation problems with a discontinuous source term.

  9. Review of Past Nuclear Accidents: Source Terms and Recorded Gamma-Ray Spectra

    OpenAIRE

    Sanderson, D.C.W.; Cresswell, A.; Allyson, J.D.; McConville, P.; Department of the Environment: Radioactive Substances Division

    1997-01-01

    Airborne gamma ray spectrometry using high volume scintillation detectors, optionally in conjunction with Ge detectors, has potential for making rapid environmental measurements in response to nuclear accidents. A literature search on past nuclear accidents has been conducted to define the source terms which have been experienced so far. Selected gamma ray spectra recorded after past accidents have also been collated to examine the complexity of observed behaviour.

  10. Project on Transfer Mechanism of Radioactive Source Term Under Severe Accident

    Institute of Scientific and Technical Information of China (English)

    SUN; Xue-ting; JI; Song-tao; CHEN; Lin-lin

    2012-01-01

    <正>The "Transfer mechanism of radioactive source term under severe accident" is a sub-project of the research program of "Mechanism and phenomenology of severe accident". An aerosol transfer mechanism experimental facility is built to simulate the passive containment cooling system (PCCS) of advanced pressurizer reactors to research effects to the transfer process of fission products under severe accident. An advanced CFD method is also utilized to research the effects. The objective of this project is to understand

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

    Science.gov (United States)

    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.

  12. Assessment of environmental arsenic levels in Prievidza district

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, T.; Hong, B.; Thornton, I.; Farago, M.; Jakubis, P.; Jakubis, M.; Pesch, B.; Ranft, U.; Nieuwenhuijsen, M.J.

    2002-07-01

    A coal-burning power station in the Nitra Valley in central Slovakia annually emitted large quantities of arsenic (up to 200 tonnes) between 1953 and 1989. Since then, pollution-control measures have reduced arsenic emissions to less than 2 tonnes a year. However, the power station was still a source of airborne arsenic pollution. As part of an EU-funded study on exposure to arsenic and cancer risk in central and Eastern Europe the authors carried out a study of environmental levels of arsenic in the homes and gardens of residents of the district. Garden soil samples (n=210), house dust samples (n=210) and composite house dust samples (n=109) were collected and analysed using inductively coupled plasma atomic absorption spectroscopy (ICP-AES) at Imperial College, London. The mean arsenic content of coal and ash in samples taken from the plant was 5 19 {mu}g/g (n=19) and 863 {mu}g/g (n=22), respectively. The geometric mean (GM) arsenic concentration of garden soils was 26 {mu}g/g (range 8.8-139.0 {mu}g/g), for house dust 11.6 {mu}g/g (range 2.1-170 {mu}g/g) and for composite house dust 9.4 {mu}g/g (range 2.3-61.5 mug/g). The correlation between the arsenic levels in soil and in house dust was 0.3 (P {lt} 0.01), in soil and composite house dust 0.4 and house dust and composite house dust 0.4 (P{lt} 0.01 for both), i.e., were moderate. Arsenic levels in both house dust and soil decreased with distance from the power station. Overall, levels in both fell by half 5 km from the point source. Weak correlations were seen between the total urinary arsenic concentrations and arsenic concentrations in composite house dust.

  13. Arsenic in New Jersey Coastal Plain streams, sediments, and shallow groundwater: effects from different geologic sources and anthropogenic inputs on biogeochemical and physical mobilization processes

    Science.gov (United States)

    Barringer, Julia L.; Reilly, Pamela A.; Eberl, Dennis D.; Mumford, Adam C.; Benzel, William M.; Szabo, Zoltan; Shourds, Jennifer L.; Young, Lily Y.

    2013-01-01

    Arsenic (As) concentrations in New Jersey Coastal Plain streams generally exceed the State Surface Water Quality Standard (0.017 micrograms per liter (µg/L)), but concentrations seldom exceed 1 µg/L in filtered stream-water samples, regardless of geologic contributions or anthropogenic inputs. Nevertheless, As concentrations in unfiltered stream water indicate substantial variation because of particle inputs from soils and sediments with differing As contents, and because of discharges from groundwater of widely varying chemistry.

  14. Development of the source term PIRT based on findings during Fukushima Daiichi NPPs accident

    Energy Technology Data Exchange (ETDEWEB)

    Suehiro, Shoichi, E-mail: suehiro-shouichi@tepsys.co.jp [TEPCO SYSTEMS Co., 2-37-28 Eitai, Koto-Ku, Tokyo 135-0034 (Japan); Sugimoto, Jun [Kyoto University, Yoshida Sakyo, Kyoto 606-8501 (Japan); Hidaka, Akihide [Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Okada, Hidetoshi [The Institute of Applied Energy, 14-2 Nishi-Shimbashi 1-Chome, Minato-ku, Tokyo 105-0003 (Japan); Mizokami, Shinya [Tokyo Electric Power Company, 1-3 Uchisaiwai-cho 1-Chome, Chiyoda-ku, Tokyo 100-8560 (Japan); Okamoto, Koji [The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki 319-1188 (Japan)

    2015-05-15

    Highlights: • We developed the source term PIRT based on findings during the Fukushima accident. • The FoM is the masses or fractions of radionuclides released into the environment. • 68 phenomena were identified as influencing to the FoM. • Radionuclide release from molten fuel had the highest score in the early phase. • MCCI, iodine chemistry, and chemical form had the highest score in the later phase. - Abstract: Research Expert Committee on Evaluation of Severe Accident of AESJ (Atomic Energy Society of Japan) has developed thermal hydraulic PIRT (Phenomena Identification and Ranking Table) and source term (ST) PIRT based on findings during the Fukushima Daiichi NPPs accident. These PIRTs aim to explore the debris distribution and the current condition in the NPPs with high accuracy and to extract higher priority from the aspect of the sophistication of the analytical technology to predict the severe accident phenomena by the analytical codes. The ST PIRT is divided into 3 phases for time domain and 9 categories for spatial domain. The 68 phenomena have been extracted and the importance from the viewpoint of the source term has been ranked through brainstorming and discussions among experts. The present paper describes the developed ST PIRT list and summarizes the high ranked phenomena in each phase.

  15. Source term assessment with ASTEC and associated uncertainty analysis using SUNSET tool

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier-Jabet, K., E-mail: karine.chevalier-jabet@irsn.fr; Cousin, F.; Cantrel, L.; Séropian, C.

    2014-06-01

    Several accidental scenarios have been simulated using the ASTEC integral IRSN-GRS code for a French 1300 MWe PWR, including several break sizes or locations, highlighting the effect of safety systems and of iodine chemistry in the reactor coolant system (RCS) and in the containment on iodine source term evaluations. Iodine chemistry in the RCS and in the containment is still subject to significant uncertainties and it is thus studied in on-going R and D programs. To assess the impact of uncertainties, ASTEC has been coupled to the IRSN uncertainty propagation and sensitivity analysis tool SUNSET. Focusing on a loss of feed-water of steam generator accident, ASTEC/SUNSET calculations have been performed to assess the effect of remaining uncertainties relative to iodine behaviour on the source term. Calculations show that the postulated lack of knowledge may impact the iodine source term in the environment by at least one decade, confirming the importance of the on-going R and D programs to improve the knowledge on iodine chemistry.

  16. Least-squares finite-element method for shallow-water equations with source terms

    Institute of Scientific and Technical Information of China (English)

    Shin-Jye Liang; Tai-Wen Hsu

    2009-01-01

    Numerical solution of shallow-water equations (SWE) has been a challenging task because of its nonlinear hyperbolic nature, admitting discontinuous solution, and the need to satisfy the C-property. The presence of source terms in momentum equations, such as the bottom slope and friction of bed, compounds the difficulties further. In this paper, a least-squares finite-element method for the space discretization and θ-method for the time integration is developed for the 2D non-conservative SWE including the source terms. Advantages of the method include: the source terms can be approximated easily with interpolation functions, no upwind scheme is needed, as well as the resulting system equations is symmetric and positive-definite, therefore, can be solved efficiently with the conjugate gradient method. The method is applied to steady and unsteady flows, subcritical and transcritical flow over a bump, 1D and 2D circular dam-break, wave past a circular cylinder, as well as wave past a hump. Computed results show good C-property, conservation property and compare well with exact solutions and other numerical results for flows with weak and mild gradient changes, but lead to inaccurate predictions for flows with strong gradient changes and discontinuities.

  17. Schematic way to find solution of the outcoupled matter wave with a source term

    Energy Technology Data Exchange (ETDEWEB)

    Prayitno, T. B. [Physics Department, Faculty of Mathematics and Natural Science, Universitas Negeri Jakarta, Jl. Pemuda Rawamangun No. 10, Jakarta, 13220 (Indonesia)

    2013-09-09

    We propose a schematic way to obtain solution of the outcoupled atom laser beam wave function in the presence of a source term where the beam is influenced by gravity. In this case, we only focus on the external potentials inside the region of Bose-Einstein condensate that are generated by electromagnetic source and gravity. Since the evolution of the atom laser beam can be portrayed through the ordinary Schrödinger equation with a source, we are allowed to express the general solution as the superposition of the homogeneous solution and particular solution. With the given external potentials and ansatz solutions, we attain that the obtained energy depends on the parameter constituting to the ratio between the longitudinal frequency and transverse frequency.

  18. Low-level waste disposal performance assessments - Total source-term analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wilhite, E.L.

    1995-12-31

    Disposal of low-level radioactive waste at Department of Energy (DOE) facilities is regulated by DOE. DOE Order 5820.2A establishes policies, guidelines, and minimum requirements for managing radioactive waste. Requirements for disposal of low-level waste emplaced after September 1988 include providing reasonable assurance of meeting stated performance objectives by completing a radiological performance assessment. Recently, the Defense Nuclear Facilities Safety Board issued Recommendation 94-2, {open_quotes}Conformance with Safety Standards at Department of Energy Low-Level Nuclear Waste and Disposal Sites.{close_quotes} One of the elements of the recommendation is that low-level waste performance assessments do not include the entire source term because low-level waste emplaced prior to September 1988, as well as other DOE sources of radioactivity in the ground, are excluded. DOE has developed and issued guidance for preliminary assessments of the impact of including the total source term in performance assessments. This paper will present issues resulting from the inclusion of all DOE sources of radioactivity in performance assessments of low-level waste disposal facilities.

  19. Arsenic speciation in Chinese Herbal Medicines and human health implication for inorganic arsenic.

    Science.gov (United States)

    Liu, Xiao-Juan; Zhao, Quan-Li; Sun, Guo-Xin; Williams, Paul; Lu, Xiu-Jun; Cai, Jing-Zhu; Liu, Wen-Ju

    2013-01-01

    Rice and drinking water are recognized as the dominant sources of arsenic (As) for human intake, while little is known about As accumulation and speciation in Chinese Herbal Medicines (CHMs), which have been available for many hundreds of years for the treatment of diseases in both eastern and western cultures. Inorganic arsenic was the predominant species in all of CHMs samples. The levels of inorganic arsenic in CHMs from fields and markets or pharmacies ranged from 63 to 550 ng/g with a mean of 208 ng/g and 94 to 8683 ng/g with a mean of 1092 ng/g, respectively. The highest concentration was found in the Chrysanthemum from pharmacies. It indicates that the risk of inorganic As in CHMs to human health is higher in medicines from markets or pharmacies than that collected directly from fields. Some CHMs may make a considerable contribution to the human intake of inorganic arsenic.

  20. Sustainable engineered processes to mitigate the global arsenic crisis in drinking water: challenges and progress.

    Science.gov (United States)

    Sarkar, Sudipta; Greenleaf, John E; Gupta, Anirban; Uy, Davin; Sengupta, Arup K

    2012-01-01

    Millions of people around the world are currently living under the threat of developing serious health problems owing to ingestion of dangerous concentrations of arsenic through their drinking water. In many places, treatment of arsenic-contaminated water is an urgent necessity owing to a lack of safe alternative sources. Sustainable production of arsenic-safe water from an arsenic-contaminated raw water source is currently a challenge. Despite the successful development in the laboratory of technologies for arsenic remediation, few have been successful in the field. A sustainable arsenic-remediation technology should be robust, composed of local resources, and user-friendly as well as must attach special consideration to the social, economic, cultural, traditional, and environmental aspects of the target community. One such technology is in operation on the Indian subcontinent. Wide-scale replication of this technology with adequate improvisation can solve the arsenic crisis prevalent in the developing world.

  1. Effect of Environmental Exposure of Arsenic on Cattle and Poultry in Nadia District, West Bengal, India

    Science.gov (United States)

    Datta, Bakul Kumar; Bhar, Moloy Kumar; Patra, Pabitra Hriday; Majumdar, Debasish; Dey, Radha Raman; Sarkar, Samar; Mandal, Tapan Kumar; Chakraborty, Animesh Kumar

    2012-01-01

    A study was undertaken to evaluate an alternative source of arsenicosis in human food chain through livestock. Thirty milch cattle and 20 poultry birds along with their eggs were selected randomly from two endemic villages of Nadia district and one nonendemic villages of Hooghly district in West Bengal, India. Milk, feces, urine, and hair samples of cattle and feed materials, such as water and straw, were collected to analyze arsenic status. Arsenic concentration in egg yolk and albumen from poultry eggs and different poultry organs after culling was estimated. Distribution of arsenic in animal body indicates that major portion of arsenic was eliminated through feces, urine, and milk. Poultry egg yolk, albumen, and poultry products retain arsenic in all organs. Cows and poultry birds reared in endemic zone retain significantly higher concentration of arsenic. Consumption of egg, agricultural produces grown in contaminated soil, and milk might have produced arsenicosis and may be considered as alternative source of arsenic contamination. PMID:22736905

  2. Diversity of carbon source metabolism of microbial community in farmland soils in an arsenic mining area%砷矿区农田土壤微生物群落碳源代谢多样性

    Institute of Scientific and Technical Information of China (English)

    华建峰; 林先贵; 蒋倩; 张华勇; 陈茜; 殷云龙

    2013-01-01

    By using Biolog technique, this paper studied the diversity of carbon source metabolism of microbial community in three farmland soils with different levels of arsenic ( As) in an As mining area, and the relationships between the diversity of the carbon source metabolism and the main soil chemical properties. The total N (TN) , total P (TP) , total K (TK) , organic matter (OM) , total Cu, and total Zn contents in the three soils were in the order of medium level As > high level As > low level As. The average well color development (AWCD), Shannon index (H'), Simpson index (D) , and Mclntosh index (U) of soil microbes were significantly higher in the soils with medium and high levels As than in the soil with low level As. The principal component analysis and the fingerprints of the physiological carbon metabolism of the microbial community in the three soils demonstrated that the microbes in the soils with medium and high levels As had a significantly higher (P<0.05) utilization rate in carbohydrates and amino acids than the microbes in the soil with low level As. The correlation analysis showed that the AWCD, H', D, and U were significantly positively correlated with the contents of soil TN, TP, OM, total As, total Cu, total Pb, and total Zn (P<0.05) , and the canonical correspondence analysis revealed that soil TP, OM, total Pb, total Zn, TN, and pH rather than soil total As were the main soil chemical properties affecting the carbon source metabolism of soil microbial community. It was considered that soil nutrients could be the main factors affecting the community structure and functions of soil microbes in long-term contaminated soils.%采用Biolog方法研究了砷(As)矿区农田土壤微生物碳源利用多样性及其与土壤化学性质的关系.结果表明:3种土壤的N、P、K、有机质(OM)、Cu和Zn全量依次为中As>高As>低As土壤.中As和高As土壤微生物平均吸光度以及多样性指数(H'、D、U)显著高于低As土壤.主成

  3. Accident source terms for light-water nuclear power plants using high-burnup or MOX fuel.

    Energy Technology Data Exchange (ETDEWEB)

    Salay, Michael (U.S. Nuclear Regulatory Commission, Washington, D.C.); Gauntt, Randall O.; Lee, Richard Y. (U.S. Nuclear Regulatory Commission, Washington, D.C.); Powers, Dana Auburn; Leonard, Mark Thomas

    2011-01-01

    Representative accident source terms patterned after the NUREG-1465 Source Term have been developed for high burnup fuel in BWRs and PWRs and for MOX fuel in a PWR with an ice-condenser containment. These source terms have been derived using nonparametric order statistics to develop distributions for the timing of radionuclide release during four accident phases and for release fractions of nine chemical classes of radionuclides as calculated with the MELCOR 1.8.5 accident analysis computer code. The accident phases are those defined in the NUREG-1465 Source Term - gap release, in-vessel release, ex-vessel release, and late in-vessel release. Important differences among the accident source terms derived here and the NUREG-1465 Source Term are not attributable to either fuel burnup or use of MOX fuel. Rather, differences among the source terms are due predominantly to improved understanding of the physics of core meltdown accidents. Heat losses from the degrading reactor core prolong the process of in-vessel release of radionuclides. Improved understanding of the chemistries of tellurium and cesium under reactor accidents changes the predicted behavior characteristics of these radioactive elements relative to what was assumed in the derivation of the NUREG-1465 Source Term. An additional radionuclide chemical class has been defined to account for release of cesium as cesium molybdate which enhances molybdenum release relative to other metallic fission products.

  4. Inverse modeling of the Chernobyl source term using atmospheric concentration and deposition measurements

    Directory of Open Access Journals (Sweden)

    N. Evangeliou

    2017-07-01

    Full Text Available This paper describes the results of an inverse modeling study for the determination of the source term of the radionuclides 134Cs, 137Cs and 131I released after the Chernobyl accident. The accident occurred on 26 April 1986 in the Former Soviet Union and released about 1019 Bq of radioactive materials that were transported as far away as the USA and Japan. Thereafter, several attempts to assess the magnitude of the emissions were made that were based on the knowledge of the core inventory and the levels of the spent fuel. More recently, when modeling tools were further developed, inverse modeling techniques were applied to the Chernobyl case for source term quantification. However, because radioactivity is a sensitive topic for the public and attracts a lot of attention, high-quality measurements, which are essential for inverse modeling, were not made available except for a few sparse activity concentration measurements far from the source and far from the main direction of the radioactive fallout. For the first time, we apply Bayesian inversion of the Chernobyl source term using not only activity concentrations but also deposition measurements from the most recent public data set. These observations refer to a data rescue attempt that started more than 10 years ago, with a final goal to provide available measurements to anyone interested. In regards to our inverse modeling results, emissions of 134Cs were estimated to be 80 PBq or 30–50 % higher than what was previously published. From the released amount of 134Cs, about 70 PBq were deposited all over Europe. Similar to 134Cs, emissions of 137Cs were estimated as 86 PBq, on the same order as previously reported results. Finally, 131I emissions of 1365 PBq were found, which are about 10 % less than the prior total releases. The inversion pushes the injection heights of the three radionuclides to higher altitudes (up to about 3 km than previously assumed (≈ 2.2 km in order

  5. Spurious Behavior of Shock-Capturing Methods: Problems Containing Stiff Source Terms and Discontinuities

    Science.gov (United States)

    Yee, Helen M. C.; Kotov, D. V.; Wang, Wei; Shu, Chi-Wang

    2013-01-01

    The goal of this paper is to relate numerical dissipations that are inherited in high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities. For pointwise evaluation of the source term, previous studies indicated that the phenomenon of wrong propagation speed of discontinuities is connected with the smearing of the discontinuity caused by the discretization of the advection term. The smearing introduces a nonequilibrium state into the calculation. Thus as soon as a nonequilibrium value is introduced in this manner, the source term turns on and immediately restores equilibrium, while at the same time shifting the discontinuity to a cell boundary. The present study is to show that the degree of wrong propagation speed of discontinuities is highly dependent on the accuracy of the numerical method. The manner in which the smearing of discontinuities is contained by the numerical method and the overall amount of numerical dissipation being employed play major roles. Moreover, employing finite time steps and grid spacings that are below the standard Courant-Friedrich-Levy (CFL) limit on shockcapturing methods for compressible Euler and Navier-Stokes equations containing stiff reacting source terms and discontinuities reveals surprising counter-intuitive results. Unlike non-reacting flows, for stiff reactions with discontinuities, employing a time step and grid spacing that are below the CFL limit (based on the homogeneous part or non-reacting part of the governing equations) does not guarantee a correct solution of the chosen governing equations. Instead, depending on the numerical method, time step and grid spacing, the numerical simulation may lead to (a) the correct solution (within the truncation error of the scheme), (b) a divergent solution, (c) a wrong propagation speed of discontinuities solution or (d) other spurious solutions that are solutions of the discretized counterparts but are not solutions of the governing equations

  6. Arsenic contamination of groundwater: Mitigation strategies and policies

    Science.gov (United States)

    Alaerts, Guy J.; Khouri, Nadim

    Contamination of groundwater by arsenic from natural geochemical sources is at present a most serious challenge in the planning of large-scale use of groundwater for drinking and other purposes. Recent improvements in detection limits of analytical instruments are allowing the correlation of health impacts such as cancer with large concentrations of arsenic in groundwater. However, there are at present no known large-scale technological solutions for the millions of people-mostly rural-who are potentially affected in developing countries. An overall framework of combating natural resource degradation is combined with case studies from Chile, Mexico, Bangladesh and elsewhere to arrive at a set of strategic recommendations for the global, national and local dimensions of the arsenic ``crisis''. The main recommendations include: the need for flexibility in the elaboration of any arsenic mitigation strategy, the improvement and large-scale use of low-cost and participatory groundwater quality testing techniques, the need to maintain consistent use of key lessons learned worldwide in water supply and sanitation and to integrate arsenic as just one other factor in providing a sustainable water supply, and the following of distinct but communicable tracks between arsenic-related developments and enhanced, long-term, sustainable water supplies. La contamination des eaux souterraines par l'arsenic provenant de sources naturelles est actuellement un sujet des plus graves dans l'organisation d'un recours à grande échelle des eaux souterraines pour la boisson et d'autres usages. De récentes améliorations dans les limites de détection des équipements analytiques permettent de corréler les effets sur la santé tels que le cancer à de fortes concentrations en arsenic dans les eaux souterraines. Toutefois, il n'existe pas actuellement de solutions technologiques à grande échelle connues pour des millions de personnes, surtout en zones rurales, qui sont potentiellement

  7. The Multimedia Environmental Pollutant Assessment System (MEPAS){reg_sign}: Source-term release formulations

    Energy Technology Data Exchange (ETDEWEB)

    Streile, G.P.; Shields, K.D.; Stroh, J.L.; Bagaasen, L.M.; Whelan, G.; McDonald, J.P.; Droppo, J.G.; Buck, J.W.

    1996-11-01

    This report is one of a series of reports that document the mathematical models in the Multimedia Environmental Pollutant Assessment System (MEPAS). Developed by Pacific Northwest National Laboratory for the US Department of Energy, MEPAS is an integrated impact assessment software implementation of physics-based fate and transport models in air, soil, and water media. Outputs are estimates of exposures and health risk assessments for radioactive and hazardous pollutants. Each of the MEPAS formulation documents covers a major MEPAS component such as source-term, atmospheric, vadose zone/groundwater, surface water, and health exposure/health impact assessment. Other MEPAS documentation reports cover the sensitivity/uncertainty formulations and the database parameter constituent property estimation methods. The pollutant source-term release component is documented in this report. MEPAS simulates the release of contaminants from a source, transport through the air, groundwater, surface water, or overland pathways, and transfer through food chains and exposure pathways to the exposed individual or population. For human health impacts, risks are computed for carcinogens and hazard quotients for noncarcinogens. MEPAS is implemented on a desktop computer with a user-friendly interface that allows the user to define the problem, input the required data, and execute the appropriate models for both deterministic and probabilistic analyses.

  8. [Acute arsenic poisoning].

    Science.gov (United States)

    Montelescaut, Etienne; Vermeersch, Véronique; Commandeur, Diane; Huynh, Sophie; Danguy des Deserts, Marc; Sapin, Jeanne; Ould-Ahmed, Mehdi; Drouillard, Isabelle

    2014-01-01

    Acute arsenic poisoning is a rare cause of suicide attempt. It causes a multiple organs failure caused by cardiogenic shock. We report the case of a patient admitted twelve hours after an ingestion of trioxide arsenic having survived thanks to a premature treatment.

  9. Chemistry aspects of the source term formation for a severe accident in a CANDU type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, A.; Constantin, M. [Institute for Nuclear Research, Pitesti (Romania)

    2013-07-15

    The progression of a severe accident in a CANDU type reactor is slow because the core is surrounded by a large quantity of heavy and light water which acts as a heat sink to remove the decay heat. Therefore, the source term formation is a complex and long process involving fission products transport and releasing in the fuel matrix, thermal hydraulics of the transport fluid in the primary heat system and containment, deposition and transport of fission products, chemistry including the interaction with the dousing system, structural materials and paints, etc. The source term is strongly dependent on initial conditions and accident type. The paper presents chemistry aspects for a severe accident in a CANDU type reactor, in terms of the retention in the primary heat system. After releasing from the fuel elements, the fission products suffer a multitude of phenomena before they are partly transferred into the containment region. The most important species involved in the deposition were identified. At the same time, the influence of the break position in the transfer fractions from the primary heat system to the containment was investigated. (orig.)

  10. Arsenic Removal by Liquid Membranes

    Directory of Open Access Journals (Sweden)

    Tiziana Marino

    2015-03-01

    Full Text Available Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III and As(V from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

  11. Behavior of arsenic in hydrometallurgical zinc production and environmental impact

    Directory of Open Access Journals (Sweden)

    Peltekov A.B.

    2014-12-01

    Full Text Available The presence of arsenic in zinc sulphide concentrates is particularly harmful, because it creates problems in zinc electrolysis. The main source of arsenic in non-ferrous metallurgy is arsenopyrite (FeAsS. In oxidative roasting of zinc concentrates, FeAsS oxidizes to arsenic oxides (As2O3, As2O5. In this connection a natural FeAsS was examined, and also the distribution of arsenic in the products of the roasting process, the cycle of sulphuric acid obtaining and the leaching of zinc calcine were studied. The arsenic contamination of soils in the vicinity of nonferrous metals smelter KCM SA, Plovdiv, Bulgaria as a result of zinc and lead productions has been studied.

  12. Grain Unloading Of Arsenic Species In Rice

    Science.gov (United States)

    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...

  13. Arsenic concentrations in Baltic Sea sediments close to chemical munitions dumpsites

    Science.gov (United States)

    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.

  14. Analysis of source term modeling for low-level radioactive waste performance assessments

    Energy Technology Data Exchange (ETDEWEB)

    Icenhour, A.S.

    1995-03-01

    Site-specific radiological performance assessments are required for the disposal of low-level radioactive waste (LLW) at both commercial and US Department of Energy facilities. This work explores source term modeling of LLW disposal facilities by using two state-of-the-art computer codes, SOURCEI and SOURCE2. An overview of the performance assessment methodology is presented, and the basic processes modeled in the SOURCE1 and SOURCE2 codes are described. Comparisons are made between the two advective models for a variety of radionuclides, transport parameters, and waste-disposal technologies. These comparisons show that, in general, the zero-order model predicts undecayed cumulative fractions leached that are slightly greater than or equal to those of the first-order model. For long-lived radionuclides, results from the two models eventually reach the same value. By contrast, for short-lived radionuclides, the zero-order model predicts a slightly higher undecayed cumulative fraction leached than does the first-order model. A new methodology, based on sensitivity and uncertainty analyses, is developed for predicting intruder scenarios. This method is demonstrated for {sup 137}Cs in a tumulus-type disposal facility. The sensitivity and uncertainty analyses incorporate input-parameter uncertainty into the evaluation of a potential time of intrusion and the remaining radionuclide inventory. Finally, conclusions from this study are presented, and recommendations for continuing work are made.

  15. A Comprehensive Probabilistic Tsunami Hazard Assessment: Multiple Sources and Short-Term Interactions

    Science.gov (United States)

    Anita, G.; Selva, J.; Laura, S.

    2011-12-01

    We develop a comprehensive and total probabilistic tsunami hazard assessment (TotPTHA), in which many different possible source types concur to the definition of the total tsunami hazard at given target sites. In a multi-hazard and multi-risk perspective, such an innovative approach allows, in principle, to consider all possible tsunamigenic sources, from seismic events, to slides, asteroids, volcanic eruptions, etc. In this respect, we also formally introduce and discuss the treatment of interaction/cascade effects in the TotPTHA analysis. We demonstrate how external triggering events may induce significant temporary variations in the tsunami hazard. Because of this, such effects should always be considered, at least in short-term applications, to obtain unbiased analyses. Finally, we prove the feasibility of the TotPTHA and of the treatment of interaction/cascade effects by applying this methodology to an ideal region with realistic characteristics (Neverland).

  16. An Organizational-Technical Concept to Deal with Open Source Software License Terms

    Directory of Open Access Journals (Sweden)

    Sergius Dyck

    2016-06-01

    Full Text Available Open source software (OSS released under various license terms is widely used as third party libraries in today's software projects. To ensure open source compliance within an organization, a strategic approach to OSS management is needed. As basis for such an approach, we introduce an organizational-technical concept for dealing with the various OSS licenses by using procedural instructions and build automation software. The concept includes the careful consideration of OSS license conditions. The results obtained from this consideration and additional necessary commitments are documented in a so-called license playbook. We introduce procedure instructions enabling a consistent approach for software development using OSS libraries. The procedure instructions are described in a way such that they can be implemented for example for Java projects using the popular build automation tool Apache Maven and the software repository tool Nexus. We give guidance on how to realize such an implementation on basis of automation tools in practice.

  17. ORIGAMI Automator Primer. Automated ORIGEN Source Terms and Spent Fuel Storage Pool Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thompson, Adam B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bowman, Stephen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peterson, Joshua L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    Source terms and spent nuclear fuel (SNF) storage pool decay heat load analyses for operating nuclear power plants require a large number of Oak Ridge Isotope Generation and Depletion (ORIGEN) calculations. SNF source term calculations also require a significant amount of bookkeeping to track quantities such as core and assembly operating histories, spent fuel pool (SFP) residence times, heavy metal masses, and enrichments. The ORIGEN Assembly Isotopics (ORIGAMI) module in the SCALE code system provides a simple scheme for entering these data. However, given the large scope of the analysis, extensive scripting is necessary to convert formats and process data to create thousands of ORIGAMI input files (one per assembly) and to process the results into formats readily usable by follow-on analysis tools. This primer describes a project within the SCALE Fulcrum graphical user interface (GUI) called ORIGAMI Automator that was developed to automate the scripting and bookkeeping in large-scale source term analyses. The ORIGAMI Automator enables the analyst to (1) easily create, view, and edit the reactor site and assembly information, (2) automatically create and run ORIGAMI inputs, and (3) analyze the results from ORIGAMI. ORIGAMI Automator uses the standard ORIGEN binary concentrations files produced by ORIGAMI, with concentrations available at all time points in each assembly’s life. The GUI plots results such as mass, concentration, activity, and decay heat using a powerful new ORIGEN Post-Processing Utility for SCALE (OPUS) GUI component. This document includes a description and user guide for the GUI, a step-by-step tutorial for a simplified scenario, and appendices that document the file structures used.

  18. Arsenic management through well modification and simulation

    Science.gov (United States)

    Halford, Keith J.; Stamos, Christina L.; Nishikawa, Tracy; Martin, Peter

    2010-01-01

    Arsenic concentrations can be managed with a relatively simple strategy of grouting instead of completely destroying a selected interval of well. The strategy of selective grouting was investigated in Antelope Valley, California, where groundwater supplies most of the water demand. Naturally occurring arsenic typically exceeds concentrations of 10 (mu or u)g/L in the water produced from these long-screened wells. The vertical distributions of arsenic concentrations in intervals of the aquifer contributing water to selected supply wells were characterized with depth-dependent water-quality sampling and flow logs. Arsenic primarily entered the lower half of the wells where lacustrine clay deposits and a deeper aquifer occurred. Five wells were modified by grouting from below the top of the lacustrine clay deposits to the bottom of the well, which reduced produced arsenic concentrations to less than 2 (mu or u)g/L in four of the five wells. Long-term viability of well modification and reduction of specific capacity was assessed for well 4-54 with AnalyzeHOLE, which creates and uses axisymmetric, radial MODFLOW models. Two radial models were calibrated to observed borehole flows, drawdowns, and transmissivity by estimating hydraulicconductivity values in the aquifer system and gravel packs of the original and modified wells. Lithology also constrained hydraulic-conductivity estimates as regularization observations. Well encrustations caused as much as 2 (mu or u)g/L increase in simulated arsenic concentration by reducing the contribution of flow from the aquifer system above the lacustrine clay deposits. Simulated arsenic concentrations in the modified well remained less than 3 (mu or u)g/L over a 20-year period.

  19. Inverse modelling-based reconstruction of the Chernobyl source term available for long-range transport

    Directory of Open Access Journals (Sweden)

    X. Davoine

    2007-01-01

    Full Text Available The reconstruction of the Chernobyl accident source term has been previously carried out using core inventories, but also back and forth confrontations between model simulations and activity concentration or deposited activity measurements. The approach presented in this paper is based on inverse modelling techniques. It relies both on the activity concentration measurements and on the adjoint of a chemistry-transport model. The location of the release is assumed to be known, and one is looking for a source term available for long-range transport that depends both on time and altitude. The method relies on the maximum entropy on the mean principle and exploits source positivity. The inversion results are mainly sensitive to two tuning parameters, a mass scale and the scale of the prior errors in the inversion. To overcome this hardship, we resort to the statistical L-curve method to estimate balanced values for these two parameters. Once this is done, many of the retrieved features of the source are robust within a reasonable range of parameter values. Our results favour the acknowledged three-step scenario, with a strong initial release (26 to 27 April, followed by a weak emission period of four days (28 April–1 May and again a release, longer but less intense than the initial one (2 May–6 May. The retrieved quantities of iodine-131, caesium-134 and caesium-137 that have been released are in good agreement with the latest reported estimations. Yet, a stronger apportionment of the total released activity is ascribed to the first period and less to the third one. Finer chronological details are obtained, such as a sequence of eruptive episodes in the first two days, likely related to the modulation of the boundary layer diurnal cycle. In addition, the first two-day release surges are found to have effectively reached an altitude up to the top of the domain (5000 m.

  20. Inverse modelling-based reconstruction of the Chernobyl source term available for long-range transport

    Directory of Open Access Journals (Sweden)

    X. Davoine

    2007-01-01

    Full Text Available The reconstruction of the Chernobyl accident source term has been previously carried out using core inventories, but also back and forth confrontations between model simulations and activity concentration or deposited activity measurements. The approach presented in this paper is based on inverse modelling techniques. It relies both on the activity concentration measurements and on the adjoint of a chemistry-transport model. The location of the release is assumed to be known, and one is looking for a source term available for long-range transport that depends both on time and altitude. The method relies on the maximum entropy on the mean principle and exploits source positivity. The inversion results are mainly sensitive to two tuning parameters, a mass scale and the scale of the prior errors in the inversion. To overcome this hardship, we resort to the statistical L-curve method to estimate balanced values for these two parameters. Once this is done, many of the retrieved features of the source are robust within a reasonable range of parameter values. Our results favour the acknowledged three-step scenario, with a strong initial release (26 to 27 April, followed by a weak emission period of four days (28 April–1 May and again a release, longer but less intense than the initial one (2 May–6 May. The retrieved quantities of iodine-131, caesium-134 and caesium-137 that have been released are in good agreement with the latest reported estimations. Yet, a stronger apportionment of the total released activity is ascribed to the first period and less to the third one. Finer chronological details are obtained, such as a sequence of eruptive episodes in the first two days, likely related to the modulation of the boundary layer diurnal cycle. In addition, the first two-day release surges are found to have effectively reached an altitude up to the top of the domain (5000 m.

  1. Source term evaluation during seismic events in the Paducah Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Chen, N.C.J.; Schmidt, R.W.; Taleyarkhan, R.P.

    1996-12-30

    The 00 buildings are expected to collapse (per guidance from structure evaluation) during a seismic event in which acceleration level exceeds 0.15g. All roof beams may slip off supports, and collapse. Equipment may slip off from supports and fall onto the floor. The cell floor is also supposed to collapse due to structural instability and distortion due to excessive acceleration forces. Following structure collapse, expansion joints in the process piping and joints between the piping and equipment are expected to fail. Preliminary analysis showed that converters are likely to remain intact. The UF{sub 6} gas released from the break will rapidly interact with moisture in the air to produce UO{sub 2}F{sub 2} and HF with exothermic energy released of {approximately}0.32 MJ/kg of UF{sub 6} reacted. Depending on the degree of mixing between UF{sub 6} gas, its reaction products, air and freon (R-114), there may occur a strong buoyancy force to disperse UO{sub 2}F{sub 2} aerosol particles that are subjected to the gravitational force for settling. Such a chemical reaction will also occur inside the converters. A substantial amount of UF{sub 6} must be stagnated at the bottom of the converters. At the interface between this stagnated UF{sub 6} and air, UF{sub 6} gas will diffuse into the air, undergo the chemical reaction with moisture there, and eventually be released through the break. Furthermore, lubricant oil fire in the building, if it occurs, will enhance the UF{sub 6} release into the atmosphere. The purpose of this study is to evaluate source term (UO{sub 2}F{sub 2} and HF) during such a seismic event. This study takes an approach using multiple steps as follows: (1) Source term evaluation at the break due to mixing between UF{sub 6} and air along with thermal buoyancy induced by chemical reaction energy, (2) Evaluation of additional source term from the converters in which a substantial UF{sub 6} vapor remains, and (3) Source term evaluation with lubricant oil

  2. PBMR radionuclide source term analysis validation based on AVR operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, C.C. [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa); Olivier, L.D. [Independent Nuclear Consultants, Grahamstown (South Africa); Stassen, E.; Reitsma, F. [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa); Merwe, J.J. van der, E-mail: hanno.vdmerwe@pbmr.co.z [PBMR, Lake Buena Vista Building, 1267 Gordon Hood Avenue, Centurion 0046 (South Africa)

    2010-10-15

    The determination of radionuclide source terms is vital for any reactor design and licensing safety evaluation. This paper provides an overview of the PBMR analysis tools with specific focus on the modelling of mobile and deposited radionuclide source terms within the pressure boundary of a typical pebble-bed high temperature reactor (HTR). The main focus is on the Dust and Activity Migration and Distribution (DAMD) software code system that models the activation, migration and time-dependent distribution of dust and atomic particles in an HTR such as the AVR and PBMR. Since DAMD provides a time-dependent systems integrated model of HTR designs, most of the obvious physical phenomena relevant to source terms are at play. These include the neutron flux, activation cross-sections, radioactive decay, dust production rates, dust impurity levels, dust filter capabilities, dust particle size distributions, thermal-hydraulic parameters influencing the migration and distribution of particles throughout the main power system and subsystems, and helium coolant leakage and make-up rates. At this stage the DAMD calibration and validation is mainly based on the operational data, experiments and measurements made during 21 years of operating life of the AVR. The comparisons of the DAMD results with various AVR measurements provide confidence in the use of DAMD for the PBMR design and safety evaluations. In addition, sensitivity analyses are performed with DAMD to determine the bounding system parameters that drive the migration and distribution of radionuclides. The use of DAMD to evaluate design configurations, e.g. the effect of the introduction and placement of filters on the radionuclide distribution, is also shown. In conclusion, the importance of a systems modelling approach for radionuclide transport and distribution within the pressure boundary of a typical HTR system, is demonstrated. Since the DAMD code system is calibrated and validated against the AVR measurements it

  3. Numerical Dissipation and Wrong Propagation Speed of Discontinuities for Stiff Source Terms

    Science.gov (United States)

    Yee, H. C.; Kotov, D. V.; Sjoegreen, B.

    2012-01-01

    In compressible turbulent combustion/nonequilibrium flows, the constructions of numerical schemes for (a) stable and accurate simulation of turbulence with strong shocks, and (b) obtaining correct propagation speed of discontinuities for stiff reacting terms on coarse grids share one important ingredient - minimization of numerical dissipation while maintaining numerical stability. Here coarse grids means standard mesh density requirement for accurate simulation of typical non-reacting flows. This dual requirement to achieve both numerical stability and accuracy with zero or minimal use of numerical dissipation is most often conflicting for existing schemes that were designed for non-reacting flows. The goal of this paper is to relate numerical dissipations that are inherited in a selected set of high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities as a function of stiffness of the source term and the grid spacing.

  4. Arsenic from community water fluoridation: quantifying the effect.

    Science.gov (United States)

    Peterson, Emily; Shapiro, Howard; Li, Ye; Minnery, John G; Copes, Ray

    2016-04-01

    Community water fluoridation is a WHO recommended strategy to prevent dental carries. One debated concern is that hydrofluorosilicic acid, used to fluoridate water, contains arsenic and poses a health risk. This study was undertaken to determine if fluoridation contributes to arsenic in drinking water, to estimate the amount of additional arsenic associated with fluoridation, and compare this to the National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard and estimates from other researchers. Using surveillance data from Ontario drinking water systems, mixed effects linear regression was performed to examine the effect of fluoridation status on the difference in arsenic concentration between raw water and treated water samples. On average, drinking water treatment was found to reduce arsenic levels in water in both fluoridated and non-fluoridated systems by 0.2 μg/L. However, fluoridated systems were associated with an additional 0.078 μg/L (95% CI 0.021, 0.136) of arsenic in water when compared to non-fluoridated systems (P = 0.008) while controlling for raw water arsenic concentrations, types of treatment processes, and source water type. Our estimate is consistent with concentrations expected from other research and is less than 10% of the NSF/ANSI standard of 1 μg/L arsenic in water. This study provides further information to inform decision-making regarding community water fluoridation.

  5. Characterization of Roseomonas and Nocardioides spp. for arsenic transformation.

    Science.gov (United States)

    Bagade, Aditi V; Bachate, Sachin P; Dholakia, Bhushan B; Giri, Ashok P; Kodam, Kisan M

    2016-11-15

    The metalloid arsenic predominantly exists in the arsenite [As(III)] and arsenate [As(V)]. These two forms are respectively oxidized and reduced by microbial redox processes. This study was designed to bioprospect arsenic tolerating bacteria from Lonar lake and to characterize their arsenic redoxing ability. Screening of sixty-nine bacterial species isolated from Lonar lake led to identification of three arsenic-oxidizing and seven arsenic-reducing species. Arsenite oxidizing isolate Roseomonas sp. L-159a being closely related to Roseomonas cervicalis ATCC 49957 oxidized 2mM As(III) in 60h. Gene expression of large and small subunits of arsenite oxidase respectively showed 15- and 17-fold higher expression. Another isolate Nocardioides sp. L-37a formed a clade with Nocardioides ghangwensis JC2055, exhibited normal growth with different carbon sources and pH ranges. It reduced 2mM As(V) in 36h and showed constitutive expression of arsenate reductase which increased over 4-fold upon As(V) exposure. Genetic markers related to arsenic transformation were identified and characterized from the two isolates. Moderate resistance against the arsenicals was exhibited by the two isolates in the range of 1-5mM for As(III) and 1-200mM for As(V). Altogether we provide multiple evidences to indicate that Roseomonas sp. and Nocardioides sp. exhibited arsenic transformation ability.

  6. Arsenic Pollution Study at Nitra-Krška Ny Location as an Example of Line Contamination

    Directory of Open Access Journals (Sweden)

    Varga Michal

    2016-05-01

    Full Text Available The aim of this article was to identify the level of arsenic in soils and water as a type of line contamination with widespread environmental impact. For this purpose, as the “model locality” was chosen the Nitra River (Krškany location situated around 80 km from the original source of contamination - Zemianske Kostoľany. EcaFlow 150 analyzer was used to identify the content of arsenic in water and soil samples, SEM and EDS were used to characterize morphology, surface area, and chemical composition of primary substrate. In Nitra-Krškany, significant values of arsenic concentrations were observed for surface water, 14.75 μg l-1, which exceeded the WHO international A limit 1.5 times, for filtered water from the sediment, 149.9 μg l-1, with the present exceedance in all categories (WHO international A limit 15 times, and for soil samples, 26.6 mg kg-1, which exceeded 2.6 times the Slovak soil legal limit (10 mg kg-1. Detection of arsenic confirmed line contamination in Nitra - Krškany. As the main source responsible for contamination there was evaluated coal combustion residuals that consist of spherical aggregates from 2 μm to 1 mm dimension, non-linear topography. This type of contamination has a long-term impact due to hazardous materials and non-stable reactive surface area.

  7. Regulatory Technology Development Plan Sodium Fast Reactor. Mechanistic Source Term Development

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David S. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, Acacia Joann [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew D. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sofu, Tanju [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-02-28

    Construction and operation of a nuclear power installation in the U.S. requires licensing by the U.S. Nuclear Regulatory Commission (NRC). A vital part of this licensing process and integrated safety assessment entails the analysis of a source term (or source terms) that represents the release of radionuclides during normal operation and accident sequences. Historically, nuclear plant source term analyses have utilized deterministic, bounding assessments of the radionuclides released to the environment. Significant advancements in technical capabilities and the knowledge state have enabled the development of more realistic analyses such that a mechanistic source term (MST) assessment is now expected to be a requirement of advanced reactor licensing. This report focuses on the state of development of an MST for a sodium fast reactor (SFR), with the intent of aiding in the process of MST definition by qualitatively identifying and characterizing the major sources and transport processes of radionuclides. Due to common design characteristics among current U.S. SFR vendor designs, a metal-fuel, pool-type SFR has been selected as the reference design for this work, with all phenomenological discussions geared toward this specific reactor configuration. This works also aims to identify the key gaps and uncertainties in the current knowledge state that must be addressed for SFR MST development. It is anticipated that this knowledge state assessment can enable the coordination of technology and analysis tool development discussions such that any knowledge gaps may be addressed. Sources of radionuclides considered in this report include releases originating both in-vessel and ex-vessel, including in-core fuel, primary sodium and cover gas cleanup systems, and spent fuel movement and handling. Transport phenomena affecting various release groups are identified and qualitatively discussed, including fuel pin and primary coolant retention, and behavior in the cover gas and

  8. Arsenic drinking water regulations in developing countries with extensive exposure.

    Science.gov (United States)

    Smith, Allan H; Smith, Meera M Hira

    2004-05-20

    The United States Public Health Service set an interim standard of 50 microg/l in 1942, but as early as 1962 the US Public Health Service had identified 10 microg/l as a goal which later became the World Health Organization Guideline for drinking water in 1992. Epidemiological studies have shown that about one in 10 people drinking water containing 500 microg/l of arsenic over many years may die from internal cancers attributable to arsenic, with lung cancer being the surprising main contributor. A prudent public health response is to reduce the permissible drinking water arsenic concentrations. However, the appropriate regulatory response in those developing countries with large populations with much higher concentrations of arsenic in drinking water, often exceeding 100 microg/l, is more complex. Malnutrition may increase risks from arsenic. There is mounting evidence that smoking and arsenic act synergistically in causing lung cancer, and smoking raises issues of public health priorities in developing countries that face massive mortality from this product. Also, setting stringent drinking water standards will impede short term solutions such as shallow dugwells. Developing countries with large populations exposed to arsenic in water might reasonably be advised to keep their arsenic drinking water standards at 50 microg/l.

  9. Toward a Mechanistic Source Term in Advanced Reactors: A Review of Past Incidents, Experiments, and Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Bucknor, Matthew; Brunett, Acacia J.; Grabaskas, David

    2016-04-17

    In 2015, as part of a Regulatory Technology Development Plan (RTDP) effort for sodium-cooled fast reactors (SFRs), Argonne National Laboratory investigated the current state of knowledge of source term development for a metal-fueled, pool-type SFR. This paper provides a summary of past domestic metal-fueled SFR incidents and experiments and highlights information relevant to source term estimations that were gathered as part of the RTDP effort. The incidents described in this paper include fuel pin failures at the Sodium Reactor Experiment (SRE) facility in July of 1959, the Fermi I meltdown that occurred in October of 1966, and the repeated melting of a fuel element within an experimental capsule at the Experimental Breeder Reactor II (EBR-II) from November 1967 to May 1968. The experiments described in this paper include the Run-Beyond-Cladding-Breach tests that were performed at EBR-II in 1985 and a series of severe transient overpower tests conducted at the Transient Reactor Test Facility (TREAT) in the mid-1980s.

  10. The Analytical Repository Source-Term (AREST) model: Description and documentation

    Energy Technology Data Exchange (ETDEWEB)

    Liebetrau, A.M.; Apted, M.J.; Engel, D.W.; Altenhofen, M.K.; Strachan, D.M.; Reid, C.R.; Windisch, C.F.; Erikson, R.L.; Johnson, K.I.

    1987-10-01

    The geologic repository system consists of several components, one of which is the engineered barrier system. The engineered barrier system interfaces with natural barriers that constitute the setting of the repository. A model that simulates the releases from the engineered barrier system into the natural barriers of the geosphere, called a source-term model, is an important component of any model for assessing the overall performance of the geologic repository system. The Analytical Repository Source-Term (AREST) model being developed is one such model. This report describes the current state of development of the AREST model and the code in which the model is implemented. The AREST model consists of three component models and five process models that describe the post-emplacement environment of a waste package. All of these components are combined within a probabilistic framework. The component models are a waste package containment (WPC) model that simulates the corrosion and degradation processes which eventually result in waste package containment failure; a waste package release (WPR) model that calculates the rates of radionuclide release from the failed waste package; and an engineered system release (ESR) model that controls the flow of information among all AREST components and process models and combines release output from the WPR model with failure times from the WPC model to produce estimates of total release. 167 refs., 40 figs., 12 tabs.

  11. In-plant source term measurements at Fort Calhoun Station, Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, N.C.; Bunting, R.L.; Croney, S.T.

    1978-04-01

    The report presents data obtained from an in-plant source term measurement program conducted for the Office of Nuclear Regulatory Research in support of the Effluent Treatment Systems Branch of the Office of Nuclear Reactor Regulation. The objective of this program is to provide operational data that can be used in the generic evaluation of plant system design in the licensing process and for updating of the calculational models used by the NRC staff in their evaluation of radioactive waste management systems for operating pressurized water reactors. A data base is provided for radioisotope inventory in plant systems, radioactive waste management system performance, and source terms for both liquid and gaseous systems. Data presented were obtained at the Fort Calhoun Station-Unit 1, operated by the Omaha Public Power District (OPPD), located at Blair, Nebraska. In-plant measurements were conducted during the time period from August, 1976 through February 1977. This plant is the first of a planned series of six (6) operating PWR's to be studied.

  12. Evaluation of source term induced by beam loss in the superconducting linear accelerator at RAON

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Jin; Kim, Su Na; Nam, Shin Woo; Chung, Yon Sei [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2014-11-15

    As a new world-class heavy ion accelerator, RAON is able to accelerate heavy ions from proton to uranium with the energy up to -400 MeV/u and produce rare isotopes. These high purity, high intensity, and high energy beams generate the various secondary radiation which will impact on the shielding aspects of the main linear accelerator tunnels. In the main tunnel the secondary neutrons are produced by uniform beam-loss or accident criteria. In this paper evaluations of several source terms induced by beam-loss will be discussed along with the physics model of the Monte Carlo simulation codes. The beam-loss criteria were tested for the evaluation of source term for the main beam line tunnel of the RAON accelerator. It was found that the amount of the secondary neutrons depends on the incident angle of projectile on the beam pipe and the mass and energy of projectile. The influence of selected physics models and libraries of MCNPX and PHITS has been examined. The secondary neutrons were produced most in the CEM and LAQGSM model.

  13. Chernobyl radiocesium in freshwater fish: Long-term dynamics and sources of variation

    Energy Technology Data Exchange (ETDEWEB)

    Sundbom, M. [Uppsala Univ., Dept. of Limnology, Uppsala (Sweden)

    2002-04-01

    The aim of this thesis was to investigate both the long-term temporal pattern and sources of individual variation for radiocesium in freshwater fish. The basis for the study is time series of {sup 137}Cs activity concentrations in fish from three lakes in the area North-west of Uppsala, Sweden that received considerable amounts of {sup 137}Cs from Chernobyl in may 1986. The lakes were Lake Ekholmssjoen, Lake Flatsjoen and Lake Siggeforasjoen, all small forest lakes, but with different morphometrical and chemical characteristics. The data were collected regularly, usually several times per year, during 1986-2000, using consistent methods. More than 7600 fish individuals from 7 species covering wide size ranges and feeding habits were analysed for {sup 137}Cs. For each fish was the length, weight, sex, and often the stomach contend recorded. The evaluation on long-term trends were based on data from all three lakes, while the study on sources of variation evaluated data from Lake Flatsjoen only. (au)

  14. Reference Spent Fuel and Its Source Terms for a Design of Deep Geological Disposal System

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dong Keun

    2005-12-15

    In this study, current status and future trend of domestic spent fuels were analyzed to propose reference spent nuclear fuel. And then, source terms needed for design of a deep geological disposal system were calculated using ORIGEN-ARP. The reference spent fuels selected based on assembly physical dimension, inventory projection, trend of initial enrichment of 235U, discharge burnup are as follows; The 17x17 Korean Optimized Fuel Assembly with initial enrichment of 4.0 wt.% 235U and discharge burnup of 45 GWD/MTU was adopted as a low-burnup representative fuel. For the high-burnup representative fuel, 16x16 Korean Standard Fuel Assembly with initial enrichment of 4.5 wt.% 235U and discharge burnup of 55 GWD/MTU was chosen. CANDU fuel with initial enrichment of 0.711 wt.% 235U and discharge burnup of 7.5 GWD/MTU was also considered. For these reference fuels, decay heat, radiation intensity and spectrum, nuclide concentration, and individual nuclide radioactivity were calculated using ORIGEN-ARP for a disposal system design. It is expected that the source terms estimated in this study will be applied to the disposal system development in the future.

  15. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish release fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.

  16. Environmental radiation safety: source term modification by soil aerosols. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Moss, O.R.; Allen, M.D.; Rossignol, E.J.; Cannon, W.C.

    1980-08-01

    The goal of this project is to provide information useful in estimating hazards related to the use of a pure refractory oxide of /sup 238/Pu as a power source in some of the space vehicles to be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere, and to impact with the earth's surface without releasing any plutonium, the possibility that such an event might produce aerosols composed of soil and /sup 238/PuO/sub 2/ cannot be absolutely excluded. This report presents the results of our most recent efforts to measure the degree to which the plutonium aerosol source term might be modified in a terrestrial environment. The five experiments described represent our best effort to use the original experimental design to study the change in the size distribution and concentration of a /sup 238/PuO/sub 2/ aerosol due to coagulation with an aerosol of clay or sandy loam soil.

  17. Plutonium isotopes and 241Am in the atmosphere of Lithuania: A comparison of different source terms

    Science.gov (United States)

    Lujanienė, G.; Valiulis, D.; Byčenkienė, S.; Šakalys, J.; Povinec, P. P.

    2012-12-01

    137Cs, 241Am and Pu isotopes collected in aerosol samples during 1994-2011 were analyzed with special emphasis on better understanding of Pu and Am behavior in the atmosphere. The results from long-term measurements of 240Pu/239Pu atom ratios showed a bimodal frequency distribution with median values of 0.195 and 0.253, indicating two main sources contributing to the Pu activities at the Vilnius sampling station. The low Pu atom ratio of 0.141 could be attributed to the weapon-grade plutonium derived from the nuclear weapon test sites. The frequency of air masses arriving from the North-West and North-East correlated with the Pu atom ratio indicating the input from the sources located in these regions (the Novaya Zemlya test site, Siberian nuclear plants), while no correlation with the Chernobyl region was observed. Measurements carried out during the Fukushima accident showed a negligible impact of this source with Pu activities by four orders of magnitude lower as compared to the Chernobyl accident. The activity concentration of actinides measured in the integrated sample collected in March-April, 2011 showed a small contribution of Pu with unusual activity and atom ratios indicating the presence of the spent fuel of different origin than that of the Chernobyl accident.

  18. Long term change in relative contribution of various source regions on the surface ozone over Japan

    Science.gov (United States)

    Nagashima, T.; Sudo, K.; Akimoto, H.; Kurokawa, J.; Ohara, T.

    2011-12-01

    Although the concentrations of O3 precursors over Japan have been decreasing in recent decades, long-term monitoring data shows that the surface concentration of O3 in Japan has increased since the mid-1980s until the present time. As the cause of this recent increase in surface O3 over Japan, the trans-boundary transport of O3 from the outside of Japan have been pointed out and discussed. In particular, transport from East Asian countries whose emissions of the O3 precursors have been greatly increasing recently due to their economic growth is likely a major cause of the observed increase in O3 over Japan. However, the long-term change in other factors that also have an influence on the O3 in Japan, such as the domestic emissions or the background O3, should also be evaluated. Here, we performed a long-term (1980-2005) simulation of the Source-Receptor (S-R) relationship for surface O3 in East Asia by utilizing the tagged tracer method with a global chemical transport model. During this period, emissions of O3 precursors in the model from East Asia, especially from China, have increased more than double, while those from North America have not change so much and those from Europe have decreased. The model simulated the long-term increasing trend in the surface O3 over Japan similar to the observation. The long-term changes of contributions from each source region of O3 showed that the largest contributor to the increasing trend of surface O3 in Japan is the increase of O3 created in planetary boundary layer (PBL) of China which accounts for 35% of the trend, and those of O3 created in PBL of Korean Peninsular and Japan account for 13% and 12%, respectively. The O3 created in free troposphere of China also increased, which account for 4% of the trend. Therefore, almost 40% of recent O3 increase in Japan can be attributed to the increase in the O3 created over China.

  19. Chronic Arsenic poisoning.

    Science.gov (United States)

    Ahsan, Tasnim; Zehra, Kaneez; Munshi, Alia; Ahsan, Samiah

    2009-02-01

    Chronic Arsenic Toxicity may have varied clinical presentations ranging from non-cancerous manifestations to malignancy of skin and different internal organs. Dermal lesions such as hyper pigmentation and hyperkeratosis, predominantly over palms and soles are diagnostic of Chronic Arsenicosis. We report two cases from a family living in Sukkur who presented with classical skin lesions described in Chronic Arsenicosis. The urine, nail and hair samples of these patients contained markedly elevated levels of arsenic. Also the water samples from their household and the neighbouring households were found to have alarming levels of inorganic Arsenic.

  20. Arsenic and Associated Trace Metals in Texas Groundwater

    Science.gov (United States)

    Lee, L.; Herbert, B. E.

    2002-12-01

    The value of groundwater has increased substantially worldwide due to expanding human consumption. Both the quantity and quality of groundwater are important considerations when constructing policies on natural resource conservation. This study is focused on evaluating groundwater quality in the state of Texas. Historical data from the Texas Water Development Board and the National Uranium Resource Evaluation were collected into a GIS database for spatial and temporal analyses. Specific attentions were placed on arsenic and other trace metals in groundwater. Recent studies in the United States have focused on isolated incidences of high arsenic occurrence, ignoring possible connections between arsenic and other trace metals. Descriptive statistics revealed strong correlations in groundwater between arsenic and other oxyanions including vanadium, selenium and molybdenum. Arsenic and associated trace metals were clustered at three physiographic hotspots, the Southern High Plains, the Gulf Coastal Plains of Texas, and West Texas. A geologic survey showed that arsenic and other trace metals in Texas groundwater follow local geologic trends. Uranium deposits and associated mineralization were found to occur in the same physiographic locations. Uranium mineralization may be a significant natural source of arsenic and other trace metals in Texas groundwater. Recharge, evaporative concentration, and aquifer characteristics were also contributing factors to the occurrence of trace metals in Texas groundwater. Spatial statistics were used to delineate natural sources from anthropogenic inputs. Similarly, the natural background was estimated from the spatial distribution of trace metal observations in Texas groundwater.

  1. DUSTMS-D: DISPOSAL UNIT SOURCE TERM - MULTIPLE SPECIES - DISTRIBUTED FAILURE DATA INPUT GUIDE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.M.

    2006-01-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). Many of these physical processes are influenced by the design of the disposal facility (e.g., how the engineered barriers control infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This has been done and the resulting models have been incorporated into the computer code DUST-MS (Disposal Unit Source Term-Multiple Species). The DUST-MS computer code is designed to model water flow, container degradation, release of contaminants from the wasteform to the contacting solution and transport through the subsurface media. Water flow through the facility over time is modeled using tabular input. Container degradation models include three types of failure rates: (a) instantaneous (all containers in a control volume fail at once), (b) uniformly distributed failures (containers fail at a linear rate between a specified starting and ending time), and (c) gaussian failure rates (containers fail at a rate determined by a mean failure time, standard deviation and gaussian distribution). Wasteform release models include four release mechanisms: (a) rinse with partitioning (inventory is released instantly upon container failure subject to equilibrium partitioning (sorption) with

  2. Phytoremediation of an arsenic-contaminated site using Pteris vittata L. and Pityrogramma calomelanos var. austroamericana: a long-term study.

    Science.gov (United States)

    Niazi, Nabeel Khan; Singh, Balwant; Van Zwieten, Lukas; Kachenko, Anthony George

    2012-09-01

    This field study investigated the phytoremediation potential of two arsenic (As) hyperaccumulating fern species, Pityrogramma calomelanos var. austroamericana and Pteris vittata over 27-month duration at a disused As-contaminated cattle-dip site located at Wollongbar, NSW, Australia. Ferns planted in January 2009 were harvested following 10, 22 and 27 months of growth. A detailed soil sampling was undertaken in June 2009 (initial, n = 42 per plot) and limited sampling in April 2011 (after 27 months, n = 15 per plot) to measure total and phosphate-extractable As concentrations in soil at 0 - 20-, 20 - 40- and 40 - 60-cm depths. The choice of the limited number of samples was considered sufficient to estimate the changes in soil As concentration following phytoremediation based on a geostatistical model. The average frond dry biomass, As concentration and As uptake were significantly (P 63 % (P  0.05), respectively, by P. vittata. Our results show that phytoremediation time based on observed changes in soil As based on limited sampling is not reliable; hence, it is recommended that the frond As uptake should be considered in order to evaluate the phytoremediation efficiency of the two fern species at the experimental site. Using As uptake of the two fern species, we estimate that with P. calomelanos var. austroamericana it would take 55 - 125 years to decrease mean total As content below the ecological investigation level (20 mg kg(-1)) in the surface and subsurface soils, whereas with P. vittata 143 - 412 years would be required to achieve this target.

  3. A note on variational multiscale methods for high-contrast heterogeneous porous media flows with rough source terms

    KAUST Repository

    Calo, Victor M.

    2011-09-01

    In this short note, we discuss variational multiscale methods for solving porous media flows in high-contrast heterogeneous media with rough source terms. Our objective is to separate, as much as possible, subgrid effects induced by the media properties from those due to heterogeneous source terms. For this reason, enriched coarse spaces designed for high-contrast multiscale problems are used to represent the effects of heterogeneities of the media. Furthermore, rough source terms are captured via auxiliary correction equations that appear in the formulation of variational multiscale methods [23]. These auxiliary equations are localized and one can use additive or multiplicative constructions for the subgrid corrections as discussed in the current paper. Our preliminary numerical results show that one can capture the effects due to both spatial heterogeneities in the coefficients (such as permeability field) and source terms (e.g., due to singular well terms) in one iteration. We test the cases for both smooth source terms and rough source terms and show that with the multiplicative correction, the numerical approximations are more accurate compared to the additive correction. © 2010 Elsevier Ltd.

  4. A novel integrated approach for the hazardous radioactive dust source terms estimation in future nuclear fusion power plants.

    Science.gov (United States)

    Poggi, L A; Malizia, A; Ciparisse, J F; Gaudio, P

    2016-10-01

    An open issue still under investigation by several international entities working on the safety and security field for the foreseen nuclear fusion reactors is the estimation of source terms that are a hazard for the operators and public, and for the machine itself in terms of efficiency and integrity in case of severe accident scenarios. Source term estimation is a crucial key safety issue to be addressed in the future reactors safety assessments, and the estimates available at the time are not sufficiently satisfactory. The lack of neutronic data along with the insufficiently accurate methodologies used until now, calls for an integrated methodology for source term estimation that can provide predictions with an adequate accuracy. This work proposes a complete methodology to estimate dust source terms starting from a broad information gathering. The wide number of parameters that can influence dust source term production is reduced with statistical tools using a combination of screening, sensitivity analysis, and uncertainty analysis. Finally, a preliminary and simplified methodology for dust source term production prediction for future devices is presented.

  5. Arsenic in the groundwater: Occurrence, toxicological activities, and remedies.

    Science.gov (United States)

    Jha, S K; Mishra, V K; Damodaran, T; Sharma, D K; Kumar, Parveen

    2017-04-03

    Arsenic (As) contamination in groundwater has become a geo-environmental as well as a toxicological problem across the globe affecting more than 100-million people in nearly 21 countries with its associated disease "arsenicosis." Arsenic poisoning may lead to fatal skin and internal cancers. In present review, an attempt has been made to generate awareness among the readers about various sources of occurrence of arsenic, its geochemistry and speciation, mobilization, metabolism, genotoxicity, and toxicological exposure on humans. The article also emphasizes the possible remedies for combating the problem. The knowledge of these facts may help to work on some workable remedial measure.

  6. Biotransformation and accumulation of arsenic in soil amended with seaweed.

    Science.gov (United States)

    Castlehouse, Hayley; Smith, Cassandra; Raab, Andrea; Deacon, Claire; Meharg, Andrew A; Feldmann, Jörg

    2003-03-01

    For many coastal regions of the world, it has been common practice to apply seaweed to the land as a soil improver and fertilizer. Seaweed is rich in arsenosugars and has a tissue concentration of arsenic up to 100 micro/g g(-1). These arsenic species are relatively nontoxic to humans; however, in the environment they may accumulate in the soil and decompose to more toxic arsenic species. The aim of this study was to determine the fate and biotransformation of these arsenosugars in soil using HPLC-ICP-MS analysis. Data from coastal soils currently manured with seaweeds were used to investigate if arsenic was accumulating in these soils. Long-term application of seaweed increased arsenic concentrations in these soils up to 10-fold (0.35 mg of As kg(-1) for nonagronomic peat, 4.3 mg of As kg(-1) for seaweed-amended peat). The biotransformation of arsenic was studied in microcosm experiments in which a sandy (machair) soil, traditionally manured with seaweed, was amended with Laminaria digitata and Fucus vesiculosus. In both seaweed species, the arsenic occurs in the form of arsenosugars (85%). The application of 50 g of seaweed to 1 kg of soil leads to an increase of arsenic in the soils, and the dominating species found in the soil pore water were dimethylarsinic acid (DMA(V)) and the inorganic species arsenate (As(V)) and arsenite (As(III)) after the initial appearance of arsenosugars. A proposed decomposition pathway of arsenosugars is discussed in which the arsenosugars are transformed to DMA(V) and further to inorganic arsenic without appreciable amounts of methylarsonic acid (MA(V)). Commercially available seaweed-based fertilizers contain arsenic concentration between 10 and 50 mg kg(-1). The arsenic species in these fertilizers depends on the manufacturing procedure. Some contain mainly arsenosugars while others contain mainly DMA(V) and inorganic arsenic. With the application rates suggested by the manufacturers, the application of these fertilizers is 2

  7. Toxic Substances Portal- Arsenic

    Science.gov (United States)

    ... a naturally occurring element widely distributed in the earth's crust. In the environment, arsenic is combined with ... workplace air (10 µg/m 3 ) for 8 hour shifts and 40 hour work weeks. top References ...

  8. Arsenic speciation results

    Data.gov (United States)

    U.S. Environmental Protection Agency — Linear combination fitting results of synchrotron data to determine arsenic speciation in soil samples. This dataset is associated with the following publication:...

  9. ENZYMOLOGY OF ARSENIC METHYLATION

    Science.gov (United States)

    Enzymology of Arsenic MethylationDavid J. Thomas, Pharmacokinetics Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park...

  10. Arsenic immunotoxicity: a review

    National Research Council Canada - National Science Library

    Dangleben, Nygerma L; Skibola, Christine F; Smith, Martyn T

    2013-01-01

    Exposure to arsenic (As) is a global public health problem because of its association with various cancers and numerous other pathological effects, and millions of people worldwide are exposed to As on a regular basis...

  11. Spread and partitioning of arsenic in soils from a mine waste site in Madrid province (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Gonzalez, M.A. [National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Serrano, S. [Institute of Agrochemistry and Food Technology, CSIC, Catedratico Agustin Escardino 9, 46980 Paterna, Valencia (Spain); Laborda, F. [Group of Analytical Spectroscopy and Sensors, Institute of Environmental Sciences, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Garrido, F., E-mail: fernando.garrido@mncn.csic.es [National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2014-12-01

    The formation of scorodite is an important mechanism for the natural attenuation of arsenic in a wide range of environments. It is dumped on site by metallurgical industries to minimize arsenic release. However, the long-term stability of these deposits is unclear. Sequential As extractions and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy were used to determine both As and Fe speciation in a small catchment area affected by a scorodite-rich waste pile at an abandoned smelting factory. Our results indicate that this deposit behaves as an acute point source of As and metal pollution and confirms the strong association of As(V) with Fe(III) oxide phases, highlighting the important role of ferrihydrite as an As scavenger in natural systems. In this seasonally variable system, other trapping forms such as jarosite-like minerals also play a role in the attenuation of As. Overall, our results demonstrate that scorodite should not be considered an environmental stable repository for As attenuation when dumped outside because natural rainfall and the resulting runoff drive As dispersion in the environment and indicate the need to monitor and reclamate As-rich mine deposits. - Highlights: • A scorodite-rich mining waste at an old smelting factory in Madrid is described. • Scorodite-rich mining wastes act as an acute point source of As pollution in soils. • Arsenic extraction and XANES analyses show ferrihydrite as an As scavenger in soils.

  12. Distributed source term analysis, a new approach to nuclear material inventory verification

    CERN Document Server

    Beddingfield, D H

    2002-01-01

    The Distributed Source-Term Analysis (DSTA) technique is a new approach to measuring in-process material holdup that is a significant departure from traditional hold-up measurement methodology. The DSTA method is a means of determining the mass of nuclear material within a large, diffuse, volume using passive neutron counting. The DSTA method is a more efficient approach than traditional methods of holdup measurement and inventory verification. The time spent in performing DSTA measurement and analysis is a fraction of that required by traditional techniques. The error ascribed to a DSTA survey result is generally less than that from traditional methods. Also, the negative bias ascribed to gamma-ray methods is greatly diminished because the DSTA method uses neutrons which are more penetrating than gamma-rays.

  13. Novel Slope Source Term Treatment for Preservation of Quiescent Steady States in Shallow Water Flows

    Directory of Open Access Journals (Sweden)

    Khawar Rehman

    2016-10-01

    Full Text Available This paper proposes a robust method for modeling shallow-water flows and near shore tsunami propagation, applicable for both simple and complex geometries with uneven beds. The novel aspect of the model includes the introduction of a new method for slope source terms treatment to preserve quiescent equilibrium over uneven topographies, applicable to both structured and unstructured mesh systems with equal accuracy. Our model is based on the Godunov-type finite volume numerical approximation. Second-order spatial and temporal accuracy is achieved through high resolution gradient reconstruction and the predictor-corrector method, respectively. The approximate Riemann solver of Harten, Lax, and van Leer with contact wave restoration (HLLC is used to compute fluxes. Comparisons of the model’s results with analytical, experimental, and published numerical solutions show that the proposed method is capable of accurately predicting experimental and real-time tsunami propagation/inundation, and dam-break flows over varying topographies.

  14. A Mechanistic Source Term Calculation for a Metal Fuel Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David; Bucknor, Matthew; Jerden, James

    2017-06-26

    A mechanistic source term (MST) calculation attempts to realistically assess the transport and release of radionuclides from a reactor system to the environment during a specific accident sequence. The U.S. Nuclear Regulatory Commission (NRC) has repeatedly stated its expectation that advanced reactor vendors will utilize an MST during the U.S. reactor licensing process. As part of a project to examine possible impediments to sodium fast reactor (SFR) licensing in the U.S., an analysis was conducted regarding the current capabilities to perform an MST for a metal fuel SFR. The purpose of the project was to identify and prioritize any gaps in current computational tools, and the associated database, for the accurate assessment of an MST. The results of the study demonstrate that an SFR MST is possible with current tools and data, but several gaps exist that may lead to possibly unacceptable levels of uncertainty, depending on the goals of the MST analysis.

  15. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-04-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory.

  16. Methods to prevent the source term of methyl lodide during a core melt accident

    Energy Technology Data Exchange (ETDEWEB)

    Karhu, A. [VTT Energy (Finland)

    1999-11-01

    The purpose of this literature review is to gather available information of the methods to prevent a source term of methyl iodide during a core melt accident. The most widely studied methods for nuclear power plants include the impregnated carbon filters and alkaline additives and sprays. It is indicated that some deficiencies of these methods may emerge. More reactive impregnants and additives could make a great improvement. As a new method in the field of nuclear applications, the potential of transition metals to decompose methyl iodide, is introduced in this review. This area would require an additional research, which could elucidate the remaining questions of the reactions. The ionization of the gaseous methyl iodide by corona-discharge reactors is also shortly described. (au)

  17. A source term estimation method for a nuclear accident using atmospheric dispersion models

    DEFF Research Database (Denmark)

    Kim, Minsik; Ohba, Ryohji; Oura, Masamichi

    2015-01-01

    The objective of this study is to develop an operational source term estimation (STE) method applicable for a nuclear accident like the incident that occurred at the Fukushima Dai-ichi nuclear power station in 2011. The new STE method presented here is based on data from atmospheric dispersion...... models and short-range observational data around the nuclear power plants.The accuracy of this method is validated with data from a wind tunnel study that involved a tracer gas release from a scaled model experiment at Tokai Daini nuclear power station in Japan. We then use the methodology developed...... and validated through the effort described in this manuscript to estimate the release rate of radioactive material from the Fukushima Dai-ichi nuclear power station....

  18. Long-term Periodicity Analysis of Polarization Variation for Radio Sources

    Indian Academy of Sciences (India)

    Yuhai Yuan

    2011-03-01

    We use the database of University of Michigan Radio Astronomy Observatory (UMRAO) at three radio bands (4.8, 8 and 14.5 GHz) to analyse the long-term polarization variation in search of the possible periodicity. Using the power spectral analysis method (PSA), the Jurkevich method and the discrete correlation function (DCF) method, we find that there are 16 sources lying in periodicity. The results show the astrophysically meaningful periodicity covering 2.1 years to 16.2 years at 4.8 GHz, 2.8 years to 16.3 years at 8 GHz, and 1.8 years to 16.6 years at 14.5 GHz.

  19. Source term and activation calculations for the new TR-FLEX cyclotron for medical applications at HZDR

    Energy Technology Data Exchange (ETDEWEB)

    Konheiser, Joerg [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactor Safety; Ferrari, A. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Radiation Physics; Magin, A. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany); Naumann, B. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Dept. of Radiation Protection and Safety; Mueller, S.E.

    2017-06-01

    The neutron source terms for a proton beam hitting an {sup 18}O-enriched water target were calculated with the radiation transport programs MCNP6 and FLUKA and were compared to source terms for exclusive {sup 18}O(p,n){sup 18}F production. To validate the radiation fields obtained in the simulations, an experimental program has been started using activation samples originally used in reactor dosimetry.

  20. A New Lattice Bhatnagar-Gross-Krook Model for the Convection-Diffusion Equation with a Source Term

    Institute of Scientific and Technical Information of China (English)

    DENG Bin; SHI Bao-Chang; WANG Guang-Chao

    2005-01-01

    @@ A new lattice Bhatnagar-Gross-Krook (LBGK) model for the convection-diffusion equation with a source term is proposed. Unlike the models proposed previously, the present model does not require any additional assumption on the source term. Numerical results are found to be in excellent agreement with the analytical solutions. It is also found that the numerical accuracy of the model is much better than that of the existing models.

  1. The aerosol at Barrow, Alaska: long-term trends and source locations

    Science.gov (United States)

    Polissar, A. V.; Hopke, P. K.; Paatero, P.; Kaufmann, Y. J.; Hall, D. K.; Bodhaine, B. A.; Dutton, E. G.; Harris, J. M.

    Aerosol data consisting of condensation nuclei (CN) counts, black carbon (BC) mass, aerosol light scattering (SC), and aerosol optical depth (AOD) measured at Barrow, Alaska from 1977 to 1994 have been analyzed by three-way positive matrix factorization (PMF3) by pooling all of the different data into one large three-way array. The PMF3 analysis identified four factors that indicate four different combinations of aerosol sources active throughout the year in Alaska. Two of the factors (F1, F2) represent Arctic haze. The first Arctic haze have factor F1 is dominant in January-February while the second factor F2 is dominant in March-April. They appear to be material that is generally ascribed to long-range transported anthropogenic particles. A lower ratio of condensation nuclei to scattering coefficient loadings is obtained for F2 indicating larger particles. Factor F3 is related to condensation nuclei. It has an annual cycle with two maxima, March and July-August indicating some involvement of marine biogenic sources. The fourth factor F4 represents the contribution to the stratospheric aerosol from the eruptions of El Chichon and Mt. Pinatubo. No significant long-term trend for F1 was detected while F2 shows a negative trend over the period from 1982 to 1994 but not over the whole measurement period. A positive trend of F3 over the whole period has been observed. This trend may be related to increased biogenic sulfur production caused by reductions in the sea-ice cover in the Arctic and/or an air temperature increase in the vicinity of Barrow. Potential source contribution function (PSCF) analysis showed that in winter and spring during 1989 to 1993 regions in Eurasia and North America are the sources of particles measured at barrow. In contrast to this, large areas in the North Pacific Ocean and the Arctic Ocean was contributed to observed high concentrations of CN in the summer season. Three-way positive matrix factorization was an effective method to extract

  2. EXAFS study on arsenic species and transformation in arsenic hyperaccumulator

    Institute of Scientific and Technical Information of China (English)

    HUANG Zechun; CHEN Tongbin; LEI Mei; HU Tiandou; HUANG Qifei

    2004-01-01

    Synchrotron radiation extended X-ray absorption fine structure (SR EXAFS) was employed to study the transformation of coordination environment and the redox speciation of arsenic in a newly discovered arsenic hyperaccumulator, Cretan brake (Pteris cretica L. var nervosa Thunb). It showed that the arsenic in the plant mainly coordinated with oxygen, except that some arsenic coordinated with S as As-GSH in root. The complexation of arsenic with GSH might not be the predominant detoxification mechanism in Cretan brake. Although some arsenic in root presented as As(V) in Na2HAsO4 treatments, most of arsenic in plant presented as As(III)-O in both treatments, indicating that As(V) tended to be reduced to As(III) after it was taken up into the root, and arsenic was kept as As(III) when it was transported to the above-ground tissues. The reduction of As(V) primarily proceeded in the root.

  3. Long-term aerosol measurements in Gran Canaria, Canary Islands: Particle concentration, sources and elemental composition

    Science.gov (United States)

    Gelado-Caballero, MaríA. D.; López-GarcíA, Patricia; Prieto, Sandra; Patey, Matthew D.; Collado, Cayetano; HéRnáNdez-Brito, José J.

    2012-02-01

    There are very few sets of long-term measurements of aerosol concentrations over the North Atlantic Ocean, yet such data is invaluable in quantifying atmospheric dust inputs to this ocean region. We present an 8-year record of total suspended particles (TSP) collected at three stations on Gran Canaria Island, Spain (Taliarte at sea level, Tafira 269 m above sea level (a.s.l.) and Pico de la Gorra 1930 m a.s.l.). Using wet and dry deposition measurements, the mean dust flux was calculated at 42.3 mg m-2 d-1. Air mass back trajectories (HYSPLIT, NOAA) suggested that the Sahara desert is the major source of African dust (dominant during 32-50% of days), while the Sahel desert was the major source only 2-10% of the time (maximum in summer). Elemental composition ratios of African samples indicate that, despite the homogeneity of the dust in collected samples, some signatures of the bedrocks can still be detected. Differences were found for the Sahel, Central Sahara and North of Sahara regions in Ti/Al, Mg/Al and Ca/Al ratios, respectively. Elements often associated with pollution (Pb, Cd, Ni, Zn) appeared to share a common origin, while Cu may have a predominantly local source, as suggested by a decrease in the enrichment factor (EF) of Cu during dust events. The inter-annual variability of dust concentrations is investigated in this work. During winter, African dust concentration measurements at the Pico de la Gorra station were found to correlate with the North Atlantic Oscillation (NAO) index.

  4. Microbial arsenic metabolism: New twists on an old poison

    Science.gov (United States)

    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.

  5. Atmospheric moisture transports to the Arctic from different reanalyses: comparative assessment and analysis of source terms

    Science.gov (United States)

    Dufour, Ambroise; Zolina, Olga; Gulev, Sergey

    2014-05-01

    Accurate knowledge of the Arctic heat and moisture balances is critically important for understanding mechanisms of polar climate change and the observed amplification of the Arctic warming. Basic characteristics of the atmosphere in the Arctic region have quite a large spread in the modern era and first generation reanalyses, thus preventing effective use of reanalyses for the assessment of atmospheric moisture and heat transports and analysis of variability in the source terms. We used Eulerian approach to derive and intercompare to each other estimates of the moisture transports in the atmosphere from 5 reanalyses (ERA-Interim, MERRA, NCEP-CFSR, JRA-25, NCEP-1). Computational procedure involved decomposition of the velocity and moisture fields into mean conditions and variations around the mean. This concept allowed for the further association of the mean and eddy transports with large scale circulation modes (mean component) and synoptic transients (eddy component). The latter was associated with the characteristics of cyclone activity derived from the same reanalyses using state of the art numerical algorithm for cyclone identification and tracking. Atmospheric moisture transport is most intense over the GIN Sea and the North European basin, however over this area of the most intense transports, the contributions from the eddy and mean transport components are not correlated hinting on different pattern of variability in moisture fluxes due to cyclone activity and mean circulation. Decadal scale variability in the atmospheric moisture transports has been further associated with the Arctic-scale and regional differences between local precipitation and evaporation as well as with the magnitude of the storage terms. Potential mechanisms of variability in these terms are discussed.

  6. A survey of arsenic in foodstuffs on sale in the United Kingdom and imported from Bangladesh.

    Science.gov (United States)

    Al Rmalli, S W; Haris, P I; Harrington, C F; Ayub, M

    2005-01-20

    Arsenic is a highly toxic element and its presence in food composites is a matter of concern to the well being of both humans and animals. Arsenic-contaminated groundwater is often used in Bangladesh and West Bengal (India) to irrigate crops used for food and animal consumption, which could potentially lead to arsenic entering the human food chain. In this study, we used graphite furnace atomic absorption spectroscopy to determine the total arsenic concentrations in a range of foodstuffs, including vegetables, rice and fish, imported into the United Kingdom from Bangladesh. The mean and range of the total arsenic concentration in all the vegetables imported from Bangladesh were 54.5 and 5-540 microg/kg, respectively. The highest arsenic values found were for the skin of Arum tuber, 540 microg/kg, followed by Arum Stem, 168 microg/kg, and Amaranthus, 160 microg/kg. Among the other samples, freshwater fish contained total arsenic levels between 97 and 1318 microg/kg. The arsenic content of the vegetables from the UK was approximately 2- to 3-fold lower than those observed for the vegetables imported from Bangladesh. The levels of arsenic found in vegetables imported from Bangladesh in this study, in some cases, are similar to those previously recorded for vegetables grown in arsenic-affected areas of West Bengal, India, although lower than the levels reported in studies from Bangladesh. While the total arsenic content detected in our study in vegetables, imported from Bangladesh, is far less than the recommended maximum permitted level of arsenic, it does provide an additional source of arsenic in the diet. This raises the possibility that the level of arsenic intake by certain sectors of the UK population may be significantly higher then the general population and requires further investigations.

  7. Prediction of Groundwater Arsenic Contamination using Geographic Information System and Artificial Neural Network

    OpenAIRE

    Md. Moqbul Hossain; Krishna Neaupane; Nitin Kumar Tripathi; Mongkut Piantanakulchai

    2013-01-01

    Ground water arsenic contamination is a well known health and environmental problem in Bangladesh. Sources of this heavy metal are known to be geogenic, however, the processes of its release into groundwater are poorly understood phenomena. In quest of mitigation of the problem it is necessary to predict probable contamination before it causes any damage to human health. Hence our research has been carried out to find the factor relations of arsenic contamination and develop an arsenic contam...

  8. Variational Iterative Refinement Source Term Estimation Algorithm Assessment for Rural and Urban Environments

    Science.gov (United States)

    Delle Monache, L.; Rodriguez, L. M.; Meech, S.; Hahn, D.; Betancourt, T.; Steinhoff, D.

    2016-12-01

    It is necessary to accurately estimate the initial source characteristics in the event of an accidental or intentional release of a Chemical, Biological, Radiological, or Nuclear (CBRN) agent into the atmosphere. The accurate estimation of the source characteristics are important because many times they are unknown and the Atmospheric Transport and Dispersion (AT&D) models rely heavily on these estimates to create hazard assessments. To correctly assess the source characteristics in an operational environment where time is critical, the National Center for Atmospheric Research (NCAR) has developed a Source Term Estimation (STE) method, known as the Variational Iterative Refinement STE algorithm (VIRSA). VIRSA consists of a combination of modeling systems. These systems include an AT&D model, its corresponding STE model, a Hybrid Lagrangian-Eulerian Plume Model (H-LEPM), and its mathematical adjoint model. In an operational scenario where we have information regarding the infrastructure of a city, the AT&D model used is the Urban Dispersion Model (UDM) and when using this model in VIRSA we refer to the system as uVIRSA. In all other scenarios where we do not have the city infrastructure information readily available, the AT&D model used is the Second-order Closure Integrated PUFF model (SCIPUFF) and the system is referred to as sVIRSA. VIRSA was originally developed using SCIPUFF 2.4 for the Defense Threat Reduction Agency and integrated into the Hazard Prediction and Assessment Capability and Joint Program for Information Systems Joint Effects Model. The results discussed here are the verification and validation of the upgraded system with SCIPUFF 3.0 and the newly implemented UDM capability. To verify uVIRSA and sVIRSA, synthetic concentration observation scenarios were created in urban and rural environments and the results of this verification are shown. Finally, we validate the STE performance of uVIRSA using scenarios from the Joint Urban 2003 (JU03

  9. The role of arsenic compounds in oxidative stress and in the development of diabetes

    Directory of Open Access Journals (Sweden)

    Anna Bizoń

    2013-09-01

    Full Text Available For many years arsenic compounds were used in medicine, including treatment of skin diseases, malaria, diabetes, malaria, stomach ulcers, leukemia and in the eighteenth and the nineteenth century formed the basis of contemporary pharmacology. Due to its toxicity and carcinogenic activity, most of the compounds of this element were removed from use. The major cause of human arsenic toxicity is attributed to contamination of potable water from natural geological sources rather than from mining, smelting and agricultural sources (pesticides or fertilizers. Tobacco smoke also contains arsenic compounds. The characteristics of severe acute arsenic toxicity in humans include gastrointestinal discomfort, vomiting, diarrhea, skin lesions or even death. Chronic exposure frequently causes vascoocclusive disease (such as Blackfoot disease, and the development of lung, skin, liver, kidney and bladder cancers. Arsenic is a pro-inflammatory metal and appears to induce oxidative stress, apoptosis, affect cell proliferation and cell cycle progression. Generation of free radicals by arsenic is associated with its genotoxicity and contributes to the development of neoplastic lesions. Exposure to arsenic can also cause damage of the central nervous system, peripheral neuropathies, and behavioral changes. It was shown the association of exposure to arsenic and type 2 diabetes. Compounds with +3 oxidation state are more toxic and can induce tumor development. Arsenic interacts with other heavy metals, e.g. enhances the toxicity of cadmium nephropathy and acts antagonistically relative to selenium. Studies on the mechanism of interacting the toxicity of arsenic in the human body are crucial and point to lack of access to pure potable water in some regions of the world. People should be aware of the risks that are associated with exposure to arsenic because it is ubiquitous in the industry, as well as the environment. Arsenic is also involved in the spread of

  10. Geogenic fluoride and arsenic contamination in the groundwater environments in Tanzania

    Science.gov (United States)

    Bhattacharya, Prosun; Lesafi, Fina; Filemon, Regina; Ligate, Fanuel; Ijumulana, Julian; Mtalo, Felix

    2016-04-01

    Adequate, safe and accessible drinking water is an important aspect to human health worldwide. Understanding this importance, the Tanzanian Government has initiated a number of programmes to ensure access to high quality water by the citizens. However, elevated concentration of geochemical pollutants in many drinking water sources pose a serious challenge to water suppliers and users in the country. Fluoride is a widespread drinking water contaminant of geogenic origin occuring in both surface- and groundwater around volcanic mountains and many parts within the East African Rift Valley in regions including Arusha (10 mg/L), Shinyanga (2.9 mg/L) and Singida (1.8 mg/L). An estimated 90% of the population living along the Rift Valley region are affected by dental or skeletal fluorosis and bone crippling because of long term exposure to very high levels of fluoride in drinking water sources. In the mining areas within Lake Victoria basin, groundwater wit elevated concentrations of arsenic has been discovered over an extended area. Most of these geochemical and naturally occurring drinking water pollutants are patchy with uncertainities in their spatial and temporal distribution patterns. The adverse health effects of skin disorder and cancer due to an elevated As concentration are reported from the North Mara gold and Geita mining areas in the Lake Victoria basin. About 30% of the water sources used for drinking in Tanzania exceed the WHO guideline values of fluoride (1.5 mg/L) and arsenic (10 μg/L). There is a scarcity of baseline information on the water quality data especially on geogenic contaminants in the groundwater and surface water as potable sources. This information is crucial in exploring sources of safe drinking water aquifers, associated human health risks of fluoride and arsenic pollution. using Laboratory based studies during the past two decades have shown promising results on the removal of fluoride and arsenic using locally available adsorbent

  11. Arsenic Species in Marine Samples

    OpenAIRE

    Francesconi, Kevin A.; Edmonds, John S.

    1998-01-01

    Arsenic occurs in seawater, in predominantly inorganic forms, at concentrations of about 1-2 μg/L. These concentrations are higher than those of most other potentially toxic metals and semimetals. Marine organisms have coped by exploiting the rich organic chemistry of arsenic to transform inorganic arsenic into a range of essentially non-toxic organoarsenic compounds. The resulting diversity of arsenic species found in marine samples is reviewed together with an overview of analytical meth...

  12. Elevated lactate dehydrogenase activity and increased cardiovascular mortality in the arsenic-endemic areas of southwestern Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Ya-Tang [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Taiwan (China); Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taiwan (China); Genomics Research Center, Academia Sinica, Taiwan (China); Chen, Chien-Jen [Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taiwan (China); Genomics Research Center, Academia Sinica, Taiwan (China); Li, Wan-Fen [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Taiwan (China); Hsu, Ling-I [Genomics Research Center, Academia Sinica, Taiwan (China); Tsai, Li-Yu; Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Taiwan (China); Sun, Chien-Wen [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Taiwan (China); Chen, Wei J., E-mail: wjchen@ntu.edu.tw [Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taiwan (China); Genetic Epidemiology Core Laboratory, National Taiwan University Center for Genomic Medicine, Taiwan (China); Wang, Shu-Li, E-mail: slwang@nhri.org.tw [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Taiwan (China); Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan (China)

    2012-08-01

    Arsenic ingestion has been linked to increasing global prevalence of and mortality from cardiovascular disease (CVD); arsenic can be removed from drinking water to reduce related health effects. Lactate dehydrogenase (LDH) is used for the evaluation of acute arsenic toxicity in vivo and in vitro, but it is not validated for the evaluation of long-term, chronic arsenic exposure. The present study examined the long-term effect of chronic arsenic exposure on CVD and serum LDH levels, after consideration of arsenic metabolism capacity. A total of 380 subjects from an arseniasis-endemic area and 303 from a non-endemic area of southwestern Taiwan were recruited in 2002. Various urinary arsenic species were analyzed using high-performance liquid chromatography (HPLC) and hydride generation systems. Fasting serum was used for quantitative determination of the total LDH activity. A significant dose–response relationship was observed between arsenic exposure and LDH elevation, independent of urinary arsenic profiles (P < 0.001). Furthermore, abnormal LDH elevation was associated with CVD mortality after adjustment for Framingham risk scores for 10-year CVD and arsenic exposure (hazard ratio, 3.98; 95% confidence interval, 1.07–14.81). LDH was elevated in subjects with arsenic exposure in a dose-dependent manner. LDH is a marker of arsenic toxicity associated with CVD mortality. Results of this study have important implications for use in ascertaining long-term arsenic exposure risk of CVD. -- Highlights: ► We showed that arsenic exposure was correlated with LDH elevation. ► LDH elevation was related to arsenic methylation capacity. ► Abnormal LDH elevation can be a marker of susceptibility to CVD mortality.

  13. Labile Organic Carbon in Recharge and its Impact on Groundwater Arsenic Concentrations in Bangladesh

    Science.gov (United States)

    Neumann, R. B.; Ashfaque, K. N.; Badruzzaman, A. M.; Ali, M.; Shoemaker, J. K.; Harvey, C. F.

    2009-12-01

    Researchers have puzzled over the origin of dissolved arsenic in the aquifers of the Ganges Delta since widespread arsenic poisoning from groundwater was publicized two decades ago. Previous work has concluded that biological oxidation of organic carbon drives geochemical transformations that mobilize arsenic from sediments; however, the source of the organic carbon that fuels these processes remains controversial. A combined hydrologic and biogeochemical analysis of a typical site in Bangladesh, where constructed ponds and groundwater-irrigated rice fields are the main sources of recharge, shows that only recharge through pond sediments provides the biologically degradable organic carbon that can drive arsenic mobilization. Numerical groundwater simulations as well as chemical and isotopic indicators suggest that contaminated groundwater originates from excavated ponds and that water originating from rice fields is low in arsenic. In fact, rice fields act as an arsenic sink. Irrigation moves arsenic-rich groundwater from the aquifers and deposits it on the rice fields. Most of the deposited arsenic does not return to the aquifers; it is sorbed by the field’s surface soil and bunds, and is swept away in the monsoon floods. The findings indicate that patterns of arsenic contamination in the shallow aquifer are due to recharge-source variation and complex three-dimensional flow.

  14. Estimate of arsenic emission amount from the coal power stations in China

    Institute of Scientific and Technical Information of China (English)

    LUO Kunli; ZHANG Xinmin; CHEN Changhe; LU Yilun

    2004-01-01

    To study the amount of arsenic emission from the coal power stations (mainly Permo-Carboniferous coal) in China in different combustion conditions, the arsenic content of the coal, the fly ash and the cinder in high- temperature power stations as well as mid-low temperature power stations have been analyzed. This note provides a rough estimate of the total amount of arsenic emission as well as emission ratio from steam coal combustion in China. The results show that by combustion of 1 t of Permo-Carbonif- erous coal (containing roughly 5 mg/kg arsenic), high-tem- perature power stations emit roughly 0.40 g arsenic into the atmosphere and the arsenic emission rate is about 7.70%; mid-low power stations emit roughly 0.15 g arsenic into the atmosphere and the arsenic emission rate is about 2.97%. A total of 600 million tons coal is burnt annually in China power stations, and the coal comes mainly from Permo- Carboniferous depositing in the North China Plate and northwest China coal mines. Taking the average arsenic content of the coal used at the value of 5 mg/kg, the total annual arsenic emission from steam coal combustion into the atmosphere is about 195.0 t. Most of the arsenic in coal can be released in the process of coal combustion, and the most of the released arsenic can be seized by the fly ash and then both of them are seized by the dust catcher of power station, so the arsenic emission ratio to the atmosphere is declined; in addition, research on the arsenic emission amount and emission rules from the coal power stations in China should go on the coal power stations with the dry-process dust catchers by the experiments results. In the wet process of dust catcher, 20% of the arsenic in the fly ash is dissolved in the water of sedimentation tank in high-temperature power station; in the mid-low temperature power station there are 70% of the arsenic in the fly ash dissolved in the water of sedimentation tank, this is an important source of arsenic pollution in

  15. Arsenic and lead distribution and mobility in lake sediments in the south-central Puget Sound watershed: the long-term impact of a metal smelter in Ruston, Washington, USA.

    Science.gov (United States)

    Gawel, James E; Asplund, Jessica A; Burdick, Sarah; Miller, Michelle; Peterson, Shawna M; Tollefson, Amanda; Ziegler, Kara

    2014-02-15

    The American Smelting and Refining Company (ASARCO) smelter in Ruston, Washington, contaminated the south-central Puget Sound region with heavy metals, including arsenic and lead. Arsenic and lead distribution in surface sediments of 26 lakes is significantly correlated with atmospheric model predictions of contaminant deposition spatially, with concentrations reaching 208 mg/kg As and 1,375 mg/kg Pb. The temporal distribution of these metals in sediment cores is consistent with the years of operation of the ASARCO smelter. In several lakes arsenic and lead levels are highest at the surface, suggesting ongoing inputs or redistribution of contaminants. Moreover, this study finds that arsenic is highly mobile in these urban lakes, with maximum dissolved arsenic concentrations proportional to surface sediment levels and reaching almost 90 μg/L As. With 83% of the lakes in the deposition zone having surface sediments exceeding published "probable effects concentrations" for arsenic and lead, this study provides evidence for possible ongoing environmental health concerns.

  16. Groundwater Arsenic Contamination in Kopruoren Basin (Kutahya), Turkey

    Science.gov (United States)

    Arslan, S.; Dokuz, U.; Celik, M.; Cheng, Z.

    2012-12-01

    Groundwater quality in the Kopruoren Basin located to the west of Kutahya city in western Anatolia was investigated. Kopruoren Basin is about 275 km2 with about 6,000 residents, but the surface and ground-water quality in this basin impacts a much larger population since the area is located upstream of Kutahya and Eskisehir plains. Groundwater occurs under confined conditions in the limestones of Pliocene units. The only silver deposit of Turkey is developed in the metamorphic basement rocks, Early Miocene volcanics and Pliocene units near Gumuskoy. The amount of silver manufactured annually comprises about 1% of the World's Silver Production. The cyanide-rich wastes of the Eti Gumus silver plant is stored in waste pools. There have been debates about the safety of this facility after a major collapse occurred in one of the pools in May 2011. In this study samples from 31 wells and 21 springs were collected in July and October 2011 and May 2012. The groundwaters are of Ca-Mg-HCO3 type, with arsenic, zinc and antimony occurring at high concentrations. Dissolved arsenic concentrations are as high as 48 ug/L in springs and 734 ug/L in well water. Arsenic in 57% of the springs and 68% of the wells exceeded the WHO guideline value (10 ug/L). Natural sources of arsenic in the area include the dissolution of arsenic-rich minerals such as realgar and orpiment associated with the mineral deposits in the southern part of the study area. In the northern part, arsenic is enriched due to the dissolution of arsenic-bearing coal deposits. Besides these natural sources of contamination, the silver mining activity could be an important anthropogenic source. The leakage of cyanide and arsenic, together with other trace elements to the environment from the waste pools, will continue to poison the environment if necessary precautions are not taken immediately.

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

    Science.gov (United States)

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

    2015-06-01

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

  18. Linking geochemical processes in mud volcanoes with arsenic mobilization driven by organic matter.

    Science.gov (United States)

    Liu, Chia-Chuan; Kar, Sandeep; Jean, Jiin-Shuh; Wang, Chung-Ho; Lee, Yao-Chang; Sracek, Ondra; Li, Zhaohui; Bundschuh, Jochen; Yang, Huai-Jen; Chen, Chien-Yen

    2013-11-15

    The present study deals with geochemical characterization of mud fluids and sediments collected from Kunshuiping (KSP), Liyushan (LYS), Wushanting (WST), Sinyangnyuhu (SYNH), Hsiaokunshui (HKS) and Yenshuikeng (YSK) mud volcanoes in southwestern Taiwan. Chemical constituents (cations, anions, trace elements, organic carbon, humic acid, and stable isotopes) in both fluids and mud were analyzed to investigate the geochemical processes and spatial variability among the mud volcanoes under consideration. Analytical results suggested that the anoxic mud volcanic fluids are highly saline, implying connate water as the probable source. The isotopic signature indicated that δ(18)O-rich fluids may be associated with silicate and carbonate mineral released through water-rock interaction, along with dehydration of clay minerals. Considerable amounts of arsenic in mud irrespective of fluid composition suggested possible release through biogeochemical processes in the subsurface environment. Sequential extraction of As from the mud indicated that As was mostly present in organic and sulphidic phases, and adsorbed on amorphous Mn oxyhydroxides. Volcanic mud and fluids are rich in organic matter (in terms of organic carbon), and the presence of humic acid in mud has implications for the binding of arsenic. Functional groups of humic acid also showed variable sources of organic matter among the mud volcanoes being examined. Because arsenate concentration in the mud fluids was found to be independent from geochemical factors, it was considered that organic matter may induce arsenic mobilization through an adsorption/desorption mechanism with humic substances under reducing conditions. Organic matter therefore plays a significant role in the mobility of arsenic in mud volcanoes.

  19. Fission Product Transport and Source Terms in HTRs: Experience from AVR Pebble Bed Reactor

    Directory of Open Access Journals (Sweden)

    Rainer Moormann

    2008-01-01

    Full Text Available Fission products deposited in the coolant circuit outside of the active core play a dominant role in source term estimations for advanced small pebble bed HTRs, particularly in design basis accidents (DBA. The deposited fission products may be released in depressurization accidents because present pebble bed HTR concepts abstain from a gas tight containment. Contamination of the circuit also hinders maintenance work. Experiments, performed from 1972 to 88 on the AVR, an experimental pebble bed HTR, allow for a deeper insight into fission product transport behavior. The activity deposition per coolant pass was lower than expected and was influenced by fission product chemistry and by presence of carbonaceous dust. The latter lead also to inconsistencies between Cs plate out experiments in laboratory and in AVR. The deposition behavior of Ag was in line with present models. Dust as activity carrier is of safety relevance because of its mobility and of its sorption capability for fission products. All metal surfaces in pebble bed reactors were covered by a carbonaceous dust layer. Dust in AVR was produced by abrasion in amounts of about 5 kg/y. Additional dust sources in AVR were ours oil ingress and peeling of fuel element surfaces due to an air ingress. Dust has a size of about 1  m, consists mainly of graphite, is partly remobilized by flow perturbations, and deposits with time constants of 1 to 2 hours. In future reactors, an efficient filtering via a gas tight containment is required because accidents with fast depressurizations induce dust mobilization. Enhanced core temperatures in normal operation as in AVR and broken fuel pebbles have to be considered, as inflammable dust concentrations in the gas phase.

  20. Revision of earthquake hypocentre locations in global bulletin data sets using source-specific station terms

    Science.gov (United States)

    Nooshiri, Nima; Saul, Joachim; Heimann, Sebastian; Tilmann, Frederik; Dahm, Torsten

    2017-02-01

    Global earthquake locations are often associated with very large systematic travel-time residuals even for clear arrivals, especially for regional and near-regional stations in subduction zones because of their strongly heterogeneous velocity structure. Travel-time corrections can drastically reduce travel-time residuals at regional stations and, in consequence, improve the relative location accuracy. We have extended the shrinking-box source-specific station terms technique to regional and teleseismic distances and adopted the algorithm for probabilistic, nonlinear, global-search location. We evaluated the potential of the method to compute precise relative hypocentre locations on a global scale. The method has been applied to two specific test regions using existing P- and pP-phase picks. The first data set consists of 3103 events along the Chilean margin and the second one comprises 1680 earthquakes in the Tonga-Fiji subduction zone. Pick data were obtained from the GEOFON earthquake bulletin, produced using data from all available, global station networks. A set of timing corrections varying as a function of source position was calculated for each seismic station. In this way, we could correct the systematic errors introduced into the locations by the inaccuracies in the assumed velocity structure without explicitly solving for a velocity model. Residual statistics show that the median absolute deviation of the travel-time residuals is reduced by 40-60 per cent at regional distances, where the velocity anomalies are strong. Moreover, the spread of the travel-time residuals decreased by ˜20 per cent at teleseismic distances (>28°). Furthermore, strong variations in initial residuals as a function of recording distance are smoothed out in the final residuals. The relocated catalogues exhibit less scattered locations in depth and sharper images of the seismicity associated with the subducting slabs. Comparison with a high-resolution local catalogue reveals that

  1. Long-term dust aerosol production from natural sources in Iceland.

    Science.gov (United States)

    Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur

    2017-02-01

    Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland is volcanic sandy deserts. Not only do natural emissions from these sources influenced by strong winds affect regional air quality in Iceland ("Reykjavik haze"), but dust particles are transported over the Atlantic ocean and Arctic Ocean >1000 km at times. The aim of this paper is to place Icelandic dust production area into international perspective, present long-term frequency of dust storm events in northeast Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in northeast Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the northeastern erosion area, indicating extreme dust plume activity and erosion within the northeastern deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and Aeolian transport during dust/volcanic ash storms in Iceland, which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust may contribute to the Arctic air pollution.

  2. Long-term fluctuations of hailstorms in South Moravia, Czech Republic: synthesis of different data sources

    Science.gov (United States)

    Chromá, Kateřina; Brázdil, Rudolf; Dolák, Lukáš; Řezníčková, Ladislava; Valášek, Hubert; Zahradníček, Pavel

    2016-04-01

    Hailstorms belong to natural phenomena causing great material damage in present time, similarly as it was in the past. In Moravia (eastern part of the Czech Republic), systematic meteorological observations started generally in the latter half of the 19th century. Therefore, in order to create long-term series of hailstorms, it is necessary to search for other sources of information. Different types of documentary evidence are used in historical climatology, such as annals, chronicles, diaries, private letters, newspapers etc. Besides them, institutional documentary evidence of economic and administrative character (e.g. taxation records) has particular importance. This study aims to create a long-term series of hailstorms in South Moravia using various types of documentary evidence (such as taxation records, family archives, chronicles and newspapers which are the most important) and systematic meteorological observations in the station network. Although available hailstorm data cover the 1541-2014 period, incomplete documentary evidence allows reasonable analysis of fluctuations in hailstorm frequency only since the 1770s. The series compiled from documentary data and systematic meteorological observations is used to identify periods of lower and higher hailstorm frequency. Existing data may be used also for the study of spatial hailstorm variability. Basic uncertainties of compiled hailstorm series are discussed. Despite some bias in hailstorm data, South-Moravian hailstorm series significantly extends our knowledge about this phenomenon in the south-eastern part of the Czech Republic. The study is a part of the research project "Hydrometeorological extremes in Southern Moravia derived from documentary evidence" supported by the Grant Agency of the Czech Republic, reg. no. 13-19831S.

  3. Release modes and processes relevant to source-term calculations at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Apted, M.J. [Intera Information Technologies, Denver (United States)

    1994-12-31

    The feasibility of permanent disposal of radioactive high-level waste (HLW) in repositories located in deep geologic formations is being studied world-wide. The most credible release pathway is interaction between groundwater and nuclear waste forms, followed by migration of radionuclide-bearing groundwater to the accessible environment. Under hydrologically unsaturated conditions, vapor transport of volatile radionuclides is also possible. The near-field encompasses the waste packages composed of engineered barriers, while the far-field includes the natural barriers. Taken together, these two subsystems define a series of multiple, redundant barriers that act to assure the safe isolation of nuclear waste. In the U.S., the Department of energy (DOE) is investigating the feasibility of safe, long-term disposal of high-level nuclear waste at the Yucca Mountain site in Nevada. The proposed repository horizon is located in non-welded tuffs within the unsaturated zone (i.e. above the water table) at Yucca Mountain. The purpose of this paper is to describe the source-term models for radionuclide release from waste packages at Yucca Mountain site. The first section describes the conceptual release modes that are relevant for this site and waste package design, based on a consideration of the performance of currently proposed engineered barriers under expected and unexpected conditions. No attempt is made to asses the reasonableness nor probability of occurrence for any specific release mode. The following section reviews the waste-form characteristics that are required to model and constrain the release of radionuclides from the waste package. The next section present mathematical models for the conceptual release modes, selected from those that have been implemented into a probabilistic total system assessment code developed for the Electric Power Research Institute (EPRI). (author) 4 figs., 35 refs.

  4. Long-term change in the source contribution to surface ozone over Japan

    Science.gov (United States)

    Nagashima, Tatsuya; Sudo, Kengo; Akimoto, Hajime; Kurokawa, Junichi; Ohara, Toshimasa

    2017-07-01

    The relative contributions of various source regions to the long-term (1980-2005) increasing trend in surface ozone (O3) over Japan were estimated by a series of tracer-tagging simulations using a global chemical transport model. The model simulated the observed increasing trend in surface O3, including its seasonal variation and geographical features, in Japan well and demonstrated the relative roles of different source regions in forming this trend. Most of the increasing trend in surface O3 over Japan ( ˜ 97 %) that was simulated was explained as the sum of trends in contributions of different regions to photochemical O3 production. The increasing trend in O3 produced in China accounted for 36 % of the total increasing trend and those in the other northeast Asian regions (the Korean Peninsula, coastal regions in East Asia, and Japan) each accounted for about 12-15 %. Furthermore, the contributions of O3 created in the entire free troposphere and in western, southern, and southeastern Asian regions also increased, and their increasing trends accounted for 16 and 7 % of the total trend, respectively. The impact of interannual variations in climate, in methane concentration, and in emission of O3 precursors from different source regions on the relative contributions of O3 created in each region estimated above was also investigated. The variation of climate and the increase in methane concentration together caused the increase of photochemical O3 production in several regions, and represented about 19 % of the total increasing trend in surface O3 over Japan. The increase in emission of O3 precursors in China caused an increase of photochemical O3 production not only in China itself but also in the other northeast Asian regions and accounted for about 46 % of the total increase in surface O3 over Japan. Similarly, the relative impact of O3 precursor emission changes in the Korean Peninsula and Japan were estimated as about 16 and 4 % of the total increasing trend

  5. Arsenic, Anaerobes, and Astrobiology

    Science.gov (United States)

    Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

    2013-12-01

    Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa

  6. Arsenic hyperaccumulator Pteris Vittata L. and its arsenic accumulation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An arsenic hyperaccumulator Pteris vittata L. (Chinese brake) was first discovered in China by means of field survey and greenhouse cultivation. Field survey showed that Chinese brake had large accumulating capacity to arsenic; the orders of arsenic content in different parts of the fern were as follows: leaves>leafstalks>roots, which is totally different from that of ordinary plants; bioaccumulation coefficients of the above ground parts of the fern decreased as a power function of soil arsenic contents. In the control of pot trials with normal unpolluted soil containing 9 mg/kg of arsenic, the bioaccumulation coefficients of the above ground parts and rhizoids of Chinese brake were as high as 71 and 80 respectively. Greenhouse cultivation in the contaminated soil from mining areas has shown that more than 1 times greater arsenic can be accumulated in the leaves of the fern than that of field samples with the largest content of 5070 mg/kg As on a dry matter basis. During greenhouse cultivation, arsenic content in the leaves of the fern increased linearly with time prolonging. Not only has Chinese brake extraordinary tolerance and accumulation to arsenic, but it grew rapidly with great biomass, wide distribution and easy adaptation to different environmental conditions as well. Therefore, it has great potential in future remediation of arsenic contamination. It also demonstrates important value for studies of arsenic physiology and biochemistry such as arsenic absorption, translocation and detoxification mechanisms in plants.

  7. Knowledge of arsenic in drinking-water: risks and avoidance in Matlab, Bangladesh.

    Science.gov (United States)

    Aziz, Sonia N; Boyle, Kevin J; Rahman, Mahfuzar

    2006-09-01

    Widespread contamination of arsenic in Bangladesh has been jeopardizing the health of millions of people. Residents of Matlab, Bangladesh, are among the millions at risk. Using bivariate models in the analysis of survey data, knowledge of health risks and avoidance of arsenic exposure in response to widespread contamination of arsenic for residents of Matlab were estimated. The models examined individuals' knowledge of an arsenic problem in the household and knowledge of specific illnesses caused by arsenic exposure. The likelihood of avoiding exposure to arsenic contamination was further examined. Results of the estimation showed that individual's knowledge of arsenic problems in the household was gathered through awareness campaigns and by word of mouth and that knowledge of illnesses was predicated on education, health, presence of children, elderly and young women. Adoption of avoidance measures was not affected by exposure to arsenic-information sources, but level of education had a statistically significant positive effect on the decision to avoid arsenic exposure. Lack of convenience of safe drinking-water practices lead people to persist in drinking arsenic-contaminated water.

  8. Comparison of sand-based water filters for point-of-use arsenic removal in China.

    Science.gov (United States)

    Smith, Kate; Li, Zhenyu; Chen, Bohan; Liang, Honggang; Zhang, Xinyi; Xu, Ruifei; Li, Zhilin; Dai, Huanfang; Wei, Caijie; Liu, Shuming

    2017-02-01

    Contamination of groundwater wells by arsenic is a major problem in China. This study compared arsenic removal efficiency of five sand-based point-of-use filters with the aim of selecting the most effective filter for use in a village in Shanxi province, where the main groundwater source had arsenic concentration >200 μg/L. A biosand filter, two arsenic biosand filters, a SONO-style filter and a version of the biosand filter with nails embedded in the sand were tested. The biosand filter with embedded nails was the most consistent and effective under the study conditions, likely due to increased contact time between water and nails and sustained corrosion. Effluent arsenic was below China's standard of 50 μg/L for more than six months after construction. The removal rate averaged 92% and was never below 86%. In comparison, arsenic removal for the nail-free biosand filter was never higher than 53% and declined with time. The arsenic biosand filter, in which nails sit in a diffuser basin above the sand, performed better but effluent arsenic almost always exceeded the standard. This highlights the positive impact on arsenic removal of embedding nails within the top layer of biosand filter sand and the promise of this low-cost filtration method for rural areas affected by arsenic contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Arsenic-mediated nephrotoxicity.

    Science.gov (United States)

    Robles-Osorio, Ma Ludivina; Sabath-Silva, Elizabeth; Sabath, Ernesto

    2015-05-01

    Chronic kidney disease (CKD) is an important global health problem that affects 8-15% of the population according to epidemiological studies done in different countries. Essential to prevention is the knowledge of the environmental factors associated with this disease, and heavy metals such as lead and cadmium are clearly associated with kidney injury and CKD progression. Arsenic is one of the most abundant contaminants in water and soil, and many epidemiological studies have found an association between arsenic and type 2 diabetes mellitus, hypertension and cancer; however, there is a scarcity of epidemiological studies about its association with kidney disease, and the evidence linking urinary arsenic excretion with CKD, higher urinary excretion of low molecular proteins, albuminuria or other markers of renal in injury is still limited, and more studies are necessary to characterize the role of arsenic on renal injury and CKD progression. Global efforts to reduce arsenic exposure remain important and research is also needed to determine whether specific therapies are beneficial in susceptible populations.

  10. [Arsenic - Poison or medicine?].

    Science.gov (United States)

    Kulik-Kupka, Karolina; Koszowska, Aneta; Brończyk-Puzoń, Anna; Nowak, Justyna; Gwizdek, Katarzyna; Zubelewicz-Szkodzińska, Barbara

    2016-01-01

    Arsenic (As) is commonly known as a poison. Only a few people know that As has also been widely used in medicine. In the past years As and its compounds were used as a medicine for the treatment of such diseases as diabetes, psoriasis, syphilis, skin ulcers and joint diseases. Nowadays As is also used especially in the treatment of patients with acute promyelocytic leukemia. The International Agency for Research on Cancer (IARC) has recognized arsenic as an element with carcinogenic effect evidenced by epidemiological studies, but as previously mentioned it is also used in the treatment of neoplastic diseases. This underlines the specificity of the arsenic effects. Arsenic occurs widely in the natural environment, for example, it is present in soil and water, which contributes to its migration to food products. Long exposure to this element may lead to liver damages and also to changes in myocardium. Bearing in mind that such serious health problems can occur, monitoring of the As presence in the environmental media plays a very important role. In addition, the occupational risk of As exposure in the workplace should be identified and checked. Also the standards for As presence in food should be established. This paper presents a review of the 2015 publications based on the Medical database like PubMed and Polish Medical Bibliography. It includes the most important information about arsenic in both forms, poison and medicine.

  11. EFFECTS OF ARSENIC EXPOSURE IN HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Aline Sueli de Lima Rodrigues

    2008-10-01

    Full Text Available In recent years, ingestion of inorganic arsenic from drinking water has emerged as an important public health concern. It enters drinking water supplies from natural deposits in the earth or from agricultural and industrial practices, mainly the mining. The health consequences of chronic arsenic exposure include increased risk for various forms of cancer and numerous pathologic effects, such as cutaneous effects (hyperpigmentation and hyperkeratoses, gastrointestinal effects, vascular effects, diabetes mellitus, and peripheral neuropathy. This way, this study presents through a critical revision of the literature, the more relevant current aspects on the immunological consequences, carcinogenic and resulting genetics of the human intoxication for arsenic. They were identified and analyzed 50 works published on the subject among the years of 1979 and 2008, being used as main sources LILACS-BIREME MEDLINE/Index Medicus, SciELO and PubMed. The specific Arsênio e saúde humana effects of the intoxication for arsenic about the human health are not still completely elucidated. Thus, is possible that this element affects functions still unknown, becoming important the scientificexploration on the subject.

  12. Semi-implicit and fully implicit shock-capturing methods for hyperbolic conservation laws with stiff source terms

    Science.gov (United States)

    Yee, H. C.; Shinn, Judy L.

    1987-01-01

    Some numerical aspects of finite-difference algorithms for nonlinear multidimensional hyperbolic conservation laws with stiff nonhomogeneous (source) terms are discussed. If the stiffness is entirely dominated by the source term, a semi-implicit shock-capturing method is proposed provided that the Jacobian of the source terms possesses certain properties. The proposed semi-implicit method can be viewed as a variant of the Bussing and Murman point-implicit scheme with a more appropriate numerical dissipation for the computation of strong shock waves. However, if the stiffness is not solely dominated by the source terms, a fully implicit method would be a better choice. The situation is complicated by problems that are higher than one dimension, and the presence of stiff source terms further complicates the solution procedures for alternating direction implicit (ADI) methods. Several alternatives are discussed. The primary motivation for constructing these schemes was to address thermally and chemically nonequilibrium flows in the hypersonic regime. Due to the unique structure of the eigenvalues and eigenvectors for fluid flows of this type, the computation can be simplified, thus providing a more efficient solution procedure than one might have anticipated.

  13. On the application of ENO scheme with subcell resolution to conservation laws with stiff source terms

    Science.gov (United States)

    Chang, Shih-Hung

    1991-01-01

    Two approaches are used to extend the essentially non-oscillatory (ENO) schemes to treat conservation laws with stiff source terms. One approach is the application of the Strang time-splitting method. Here the basic ENO scheme and the Harten modification using subcell resolution (SR), ENO/SR scheme, are extended this way. The other approach is a direct method and a modification of the ENO/SR. Here the technique of ENO reconstruction with subcell resolution is used to locate the discontinuity within a cell and the time evolution is then accomplished by solving the differential equation along characteristics locally and advancing in the characteristic direction. This scheme is denoted ENO/SRCD (subcell resolution - characteristic direction). All the schemes are tested on the equation of LeVeque and Yee (NASA-TM-100075, 1988) modeling reacting flow problems. Numerical results show that these schemes handle this intriguing model problem very well, especially with ENO/SRCD which produces perfect resolution at the discontinuity.

  14. Effect of hypoiodous acid volatility on the iodine source term in reactor accidents

    Energy Technology Data Exchange (ETDEWEB)

    Routamo, T. [Imatran Voima Oy, Vantaa (Finland)

    1996-12-01

    A FORTRAN code ACT WATCH has been developed to establish an improved understanding of essential radionuclide behaviour mechanisms, especially related to iodine chemistry, in reactor accidents. The accident scenarios calculated in this paper are based on the Loss of Coolant accident at the Loviisa Nuclear Power Plant. The effect of different airborne species, especially HIO, on the iodine source term has been studied. The main cause of the high HIO release in the system modelled is the increase of I{sub 2} hydrolysis rate along with the temperature increase, which accelerates HIO production. Due to the high radiation level near the reactor core, I{sub 2} is produced from I{sup -}very rapidly. High temperature in the reactor coolant causes I{sub 2} to be transformed into HIO and through the boiling of the coolant volatile I{sub 2} and HIO are transferred efficiently into the gas phase. High filtration efficiency for particulate iodine causes I{sup -} release to be much lower than those of I{sub 2} and HIO. (author) 15 figs., 1 tab., refs.

  15. Long-term Performance of Moderate Heat Portland Cement with Double-expansive Sources

    Institute of Scientific and Technical Information of China (English)

    YE Qing; CHEN Huxing; KONG Deyu; WANG Shangxian; LOU Zonghan

    2007-01-01

    The long-term performance of moderate heat Portland cement with double-expansive sources (DE cement) in the system of high MgO clinker and gypsum was studied by XRD, SEM/EDAX and test methods for strength and expansion of cement. Results indicate that the periclase particle, whose size was 5-7.5 μm in DE cement clinker containing 4.8 % MgO, existed individually. The periclase hydration in hardened DE cement paste started at about 60 days and completed up to 2 000 days, and ettringite in the paste was stable from 3 days to 2 000 days. Under the conditions of 4.5%-5.0 % MgO in clinker and 2.8%-3.4 %SO3 in cement,ettringite expansion and brucite expansion in DE cement paste had a continuity, entirety and stability. At the ages of 90, 365, 730 and 2 000 days the expansion of the paste reached 0.07%-0.11%, 0.16%-0.21%, 0.21%-0.27% and 0.29%-0.38 %, respectively. The results suggest that by using this cement in mass concrete it may compensate its temperature shrinkage and autogenous shrinkage to some extent.

  16. Preliminary Evaluation on In-vessel Source Term based on 4S Methodology in PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong Won; Chang, Won-Pyo; Seong, Seung Hwan; Ahn, Sang June; Kang, Seok Hun; Choi, Chi-Woong; Lee, Jin Yoo; Lee, Kwi Lim; Jeong, Jae-Ho; Jeong, Taekyeong; Ha, Kwi-Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    This strategy requires nuclear plants to have features that prevent radionuclide release and multiple barriers to the escape from the plants of any radionuclides that are released despite preventive measures. Considerations of the ability to prevent and mitigate release of radionuclides arise at numerous places in the safety regulations of nuclear plants. The effectiveness of mitigative capabilities in nuclear plants is subject to quantitative analysis. The radionuclide input to these quantitative analyses of effectiveness is the Source Term (ST). All features of the composition, magnitude, timing, chemical form and physical form of accidental radionuclide release constitute the ST. Also, ST is defined as the release of radionuclides from the fuel and coolant into the containment, and subsequently to the environment. The many assumptions and equations evaluated in 4S are used. The in-vessel STs are calculated through several phases: The inventory of each radionuclide is calculated by ORIGEN-2 code using the peak burnup conditions. The nominal value of the radiological inventory is multiplied by a factor of 1.5 as an uncertainty margin to give the radiological inventory. ST in the release from the core to primary sodium is calculated by using the assumption of 4S methodology. Lastly, ST in the release from the primary sodium to cover gas space is calculated by using the assumption of 4S methodology.

  17. Heat Loss in a Laser-Driven, Magnetized, X-Ray Source with Thermoelectric Terms

    Science.gov (United States)

    Giuliani, J. L.; Velikovich, A. L.; Kemp, G. E.; Colvin, J. D.; Koning, J.; Fournier, K. B.

    2016-10-01

    The efficiency of laser-driven K-shell radiation sources, i.e., pipes containing a gas or a metal foam, may be improved by using an axial magnetic field to thermally insulate the pipe wall from the hot interior. A planar, self-similar solution for the magnetic and thermal diffusion is developed to model the near wall physics that includes the thermoelectric Nernst and Ettingshausen effects. This solution extends previous work for the MagLIF concept to include the full dependence of the transport coefficients on the electron Hall parameter. The analytic solution assumes a constant pressure. This case is matched with a 1D MHD code, which is then applied to the case allowing for pressure gradients. These numerical solutions are found to evolve toward the self-similar ones. The variation of the time integrated heat loss with and without the thermoelectric terms will be examined. The present work provides a verification test for general MHD codes that use Braginskii's or Epperlein-Haines' transport model to account for thermoelectric effects. NRL supported by the DOE/NNSA. LLNL work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  18. Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Trial Calculation. Work Plan

    Energy Technology Data Exchange (ETDEWEB)

    Grabaskas, David [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, James [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, Acacia J. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    The overall objective of the SFR Regulatory Technology Development Plan (RTDP) effort is to identify and address potential impediments to the SFR regulatory licensing process. In FY14, an analysis by Argonne identified the development of an SFR-specific MST methodology as an existing licensing gap with high regulatory importance and a potentially long lead-time to closure. This work was followed by an initial examination of the current state-of-knowledge regarding SFR source term development (ANLART-3), which reported several potential gaps. Among these were the potential inadequacies of current computational tools to properly model and assess the transport and retention of radionuclides during a metal fuel pool-type SFR core damage incident. The objective of the current work is to determine the adequacy of existing computational tools, and the associated knowledge database, for the calculation of an SFR MST. To accomplish this task, a trial MST calculation will be performed using available computational tools to establish their limitations with regard to relevant radionuclide release/retention/transport phenomena. The application of existing modeling tools will provide a definitive test to assess their suitability for an SFR MST calculation, while also identifying potential gaps in the current knowledge base and providing insight into open issues regarding regulatory criteria/requirements. The findings of this analysis will assist in determining future research and development needs.

  19. LMFBR source term experiments in the Fuel Aerosol Simulant Test (FAST) facility

    Energy Technology Data Exchange (ETDEWEB)

    Petrykowski, J.C.; Longest, A.W.

    1985-01-01

    The transport of uranium dioxide (UO/sub 2/) aerosol through liquid sodium was studied in a series of ten experiments in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory (ORNL). The experiments were designed to provide a mechanistic basis for evaluating the radiological source term associated with a postulated, energetic core disruptive accident (CDA) in a liquid metal fast breeder reactor (LMFBR). Aerosol was generated by capacitor discharge vaporization of UO/sub 2/ pellets which were submerged in a sodium pool under an argon cover gas. Measurements of the pool and cover gas pressures were used to study the transport of aerosol contained by vapor bubbles within the pool. Samples of cover gas were filtered to determine the quantity of aerosol released from the pool. The depth at which the aerosol was generated was found to be the most critical parameter affecting release. The largest release was observed in the baseline experiment where the sample was vaporized above the sodium pool. In the nine ''undersodium'' experiments aerosol was generated beneath the surface of the pool at depths varying from 30 to 1060 mm. The mass of aerosol released from the pool was found to be a very small fraction of the original specimen. It appears that the bulk of aerosol was contained by bubbles which collapsed within the pool. 18 refs., 11 figs., 4 tabs.

  20. On the convergence rate of operator splitting for Hamilton-Jacobi equations with source terms

    Energy Technology Data Exchange (ETDEWEB)

    Jakobsen, Espen R.; Karlsen, Kenneth H.; Risebro, Nils Henrik

    2000-02-01

    We establish a rate of convergence for a semi-discrete operator splitting method applied to Hamilton-Jacobi equations with source terms. The method is based on sequentially solving a Hamilton-Jacobi equation and an ordinary differential equation. The Hamilton-Jacobi equation is solved exactly while the ordinary differential equation is solved exactly or by an explicit Euler method. We prove that the L{sup {infinity}} error associated with the operator splitting method is bounded by O({delta}t), where {delta}t is the splitting (or time) step. This error bound is an improvement over the existing O((sqroot)({delta}t)) bound due to Souganidis [40]. In the one dimensional case, we present a fully discrete splitting method based on an unconditionally stable front tracking method for homogenuous Hamilton-Jacobi equations. It is proved that this fully discrete splitting method possesses a linear convergence rate. Moreover, numerical results are presented to illustrate the theoreticle convergence results. (author)

  1. Long-term effects of lead poisoning on bone mineralization in vultures exposed to ammunition sources

    Energy Technology Data Exchange (ETDEWEB)

    Gangoso, Laura [Department of Conservation Biology, Estacion Biologica de Donana, C.S.I.C., Avda Ma Luisa s/n, 41013 Sevilla (Spain)], E-mail: laurag@ebd.csic.es; Alvarez-Lloret, Pedro [Department of Mineralogy and Petrology, University of Granada, Avda Fuentenueva s/n, 18002 Granada (Spain)], E-mail: pedalv@ugr.es; Rodriguez-Navarro, Alejandro A.B. [Department of Mineralogy and Petrology, University of Granada, Avda Fuentenueva s/n, 18002 Granada (Spain)], E-mail: anava@ugr.es; Mateo, Rafael [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo s/n, 13071 Ciudad Real (Spain)], E-mail: Rafael.Mateo@uclm.es; Hiraldo, Fernando [Department of Conservation Biology, Estacion Biologica de Donana, C.S.I.C., Avda Ma Luisa s/n, 41013 Sevilla (Spain)], E-mail: hiraldo@ebd.csic.es; Donazar, Jose Antonio [Department of Conservation Biology, Estacion Biologica de Donana, C.S.I.C., Avda Ma Luisa s/n, 41013 Sevilla (Spain)], E-mail: donazar@ebd.csic.es

    2009-02-15

    Long-lived species are particularly susceptible to bioaccumulation of lead in bone tissues. In this paper we gain insights into the sublethal effects of lead contamination on Egyptian vultures (Neophron percnopterus). Our approach was done on the comparison of two populations (Canary Islands and Iberian Peninsula) differing in exposures to the ingestion of lead ammunition. Blood lead levels were higher in the island population (Canary Islands range: 5.10-1780 {mu}g L{sup -1}n = 137; Iberian Peninsula range: 5.60-217.30 {mu}g L{sup -1}n = 32) showing clear seasonal trends, peaking during the hunting season. Moreover, males were more susceptible to lead accumulation than females. Bone lead concentration increased with age, reflecting a bioaccumulation effect. The bone composition was significantly altered by this contaminant: the mineralization degree decreased as lead concentration levels increased. These results demonstrate the existence of long-term effects of lead poisoning, which may be of importance in the declines of threatened populations of long-lived species exposed to this contaminant. - Bone lead accumulation decreases the degree of bone mineralization in vultures exposed to ammunition sources.

  2. Groundwater arsenic contamination and its health effects in India

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Chatterjee, Amit; Das, Dipankar; Nayak, Biswajit; Pal, Arup; Chowdhury, Uttam Kumar; Ahmed, Sad; Biswas, Bhajan Kumar; Sengupta, Mrinal Kumar; Hossain, Md. Amir; Samanta, Gautam; Roy, M. M.; Dutta, Rathindra Nath; Saha, Khitish Chandra; Mukherjee, Subhas Chandra; Pati, Shyamapada; Kar, Probir Bijoy; Mukherjee, Adreesh; Kumar, Manoj

    2017-03-01

    During a 28-year field survey in India (1988-2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

  3. Groundwater arsenic contamination and its health effects in India

    Science.gov (United States)

    Chakraborti, Dipankar; Rahman, Mohammad Mahmudur; Das, Bhaskar; Chatterjee, Amit; Das, Dipankar; Nayak, Biswajit; Pal, Arup; Chowdhury, Uttam Kumar; Ahmed, Sad; Biswas, Bhajan Kumar; Sengupta, Mrinal Kumar; Hossain, Md. Amir; Samanta, Gautam; Roy, M. M.; Dutta, Rathindra Nath; Saha, Khitish Chandra; Mukherjee, Subhas Chandra; Pati, Shyamapada; Kar, Probir Bijoy; Mukherjee, Adreesh; Kumar, Manoj

    2017-06-01

    During a 28-year field survey in India (1988-2016), groundwater arsenic contamination and its health effects were registered in the states of West Bengal, Jharkhand, Bihar and Uttar Pradesh in the Ganga River flood plain, and the states of Assam and Manipur in the flood plain of Brahamaputra and Imphal rivers. Groundwater of Rajnandgaon village in Chhattisgarh state, which is not in a flood plain, is also arsenic contaminated. More than 170,000 tubewell water samples from the affected states were analyzed and half of the samples had arsenic >10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.

  4. Alternative Options for Safe Drinking Water in Arsenic and Salinity Affected Bornal-Iliasabad Union of Kalia Upazila, Narail District, Bangladesh

    Science.gov (United States)

    Rahman, M. M.; Hasan, M. A.; Ahmed, K. M.; Nawrin, N.

    2016-12-01

    The study area, Bornal-Ilisabad union, Kalia, Narail is one of the most vulnerable areas of Bangladesh in terms of access to safe drinking water. Shallow groundwater of this area is highly arsenic contaminated (mostly >500 μg/L) and deep groundwater is saline (EC ranges 1 to 8 mS/cm). Local communities rely on rainwater for drinking and cooking purposes during the monsoon and rest of the year they use surface water from pond which are mostly polluted. In areas where surface water is not available people are compelled to use arsenic contaminated groundwater and thus exposing themselves to serious health hazard. Principal objective of the research is to evaluate the effectiveness of managed aquifer recharge (MAR) and subsurface arsenic removal (SAR) technology in mitigating groundwater salinity and arsenic, to provide alternative sources of safe water. Surface water (pond water) and rainwater collected from roof top are used as source water to be recharged into the target aquifer for the MAR system. Source water is filtered through a sand filtration unit to remove turbidity and microorganisms before recharging through infiltration wells. For SAR system, on the other hand, a certain volume (2000L) of groundwater is abstracted from the target aquifer and then aerated for about half an hour to saturate with oxygen. The oxygenated water is injected into the aquifer and kept there for 6-8 hours and then abstracted for use. The MAR system constructed in the study area is found very effective in reducing groundwater salinity. The electrical conductivity (EC) of the groundwater of MAR system has been reduced 72-81% from the initial EC value of 3.4 mS/cm. A significant improvement in groundwater arsenic and iron concentration is also observed. The system is yielding groundwater with arsenic within permissible limit of Bangladesh drinking water standard (50 μg/L) which was 100 μg/L before introduction of MAR system. The SAR system is also found effective in reducing

  5. Mode of occurrence of arsenic in four US coals

    Science.gov (United States)

    Kolker, A.; Huggins, Frank E.; Palmer, C.A.; Shah, N.; Crowley, S.S.; Huffman, G.P.; Finkelman, R.B.

    2000-01-01

    An integrated analytical approach has been used to determine the mode of occurrence of arsenic in samples of four widely used US coals: the Pittsburgh, Illinois #6, Elkhorn/Hazard, and Wyodak. Results from selective leaching, X-ray absorption fine structure (XAFS) spectroscopy, and electron microprobe analysis show that pyrite is the principal source of arsenic in the three bituminous coals, but the concentration of As in pyrite varies widely. The Wyodak sample contains very little pyrite; its arsenic appears to be primarily associated with organics, as As3+, or as arsenate. Significant (10-40%) fractions of arsenate, derived from pyrite oxidation, are also present in the three bituminous coal samples. This information is essential in developing predictive models for arsenic behavior during coal combustion and in other environmental settings.

  6. High-order scheme for the source-sink term in a one-dimensional water temperature model

    Science.gov (United States)

    Jing, Zheng; Kang, Ling

    2017-01-01

    The source-sink term in water temperature models represents the net heat absorbed or released by a water system. This term is very important because it accounts for solar radiation that can significantly affect water temperature, especially in lakes. However, existing numerical methods for discretizing the source-sink term are very simplistic, causing significant deviations between simulation results and measured data. To address this problem, we present a numerical method specific to the source-sink term. A vertical one-dimensional heat conduction equation was chosen to describe water temperature changes. A two-step operator-splitting method was adopted as the numerical solution. In the first step, using the undetermined coefficient method, a high-order scheme was adopted for discretizing the source-sink term. In the second step, the diffusion term was discretized using the Crank-Nicolson scheme. The effectiveness and capability of the numerical method was assessed by performing numerical tests. Then, the proposed numerical method was applied to a simulation of Guozheng Lake (located in central China). The modeling results were in an excellent agreement with measured data. PMID:28264005

  7. The Long-term Variability of the X-Ray Sources in NGC 6946 and NGC 4485/4490

    CERN Document Server

    Fridriksson, Joel K; Lewin, Walter H G; Kong, Albert K H; Pooley, David

    2008-01-01

    We analyze data from five Chandra observations of the spiral galaxy NGC 6946, and from three Chandra observations of the irregular/spiral interacting galaxy pair NGC 4485/4490, with an emphasis on investigating the long-term variability exhibited by the source populations. We detect 90 point sources coincident with NGC 6946 down to luminosities of a few times 10^36 erg/s, and 38 sources coincident with NGC 4485/90 down to a luminosity of ~1x10^37 erg/s. Twenty-five (fifteen) sources in NGC 6946 (NGC 4485/90) exhibit long-term (i.e., weeks to years) variability in luminosity; eleven (four) are transient candidates. The single ultraluminous X-ray source (ULX) in NGC 6946 and all but one of the eight ULXs in NGC 4485/90 exhibit long-term flux variability. Two of the ULXs in NGC 4485/90 have not been identified before as ultraluminous sources. The widespread variability in both systems is indicative of the populations being dominated by X-ray binaries, and this is supported by the X-ray colors of the sources. The...

  8. Distribution of arsenic concentrations in groundwater of the Seymour Aquifer, Texas, USA.

    Science.gov (United States)

    Hudak, Paul F

    2008-02-01

    The purpose of this study was to investigate arsenic concentrations in the Seymour Aquifer. Discontinuous alluvium of the aquifer occupies a broad, semi-arid region of northern Texas, USA. Throughout the formation's outcrop, permeable deposits and unconfined conditions may facilitate downward travel of contaminants applied to the land surface. Past agricultural practices are a potential source of arsenic to the aquifer. However, of 64 water samples analyzed from 2001-2004, only one exceeded the maximum contaminant level (MCL) of 10 microg/l for arsenic in drinking water. The median arsenic concentration was 2.7 microg/l, and 34% of samples had arsenic concentrations less than 2 microg/l. No relationship between arsenic concentration and well depth was observed.

  9. A cross sectional study of anemia and iron deficiency as risk factors for arsenic-induced skin lesions in Bangladeshi women

    OpenAIRE

    Kile, Molly L.; Faraj, Joycelyn M.; Ronnenberg, Alayne G.; Quamruzzaman, Quazi; Rahman, Mahmudar; Mostofa, Golam; Afroz, Sakila; Christiani, David C.

    2016-01-01

    Background In the Ganges Delta, chronic arsenic poisoning is a health concern affecting millions of people who rely on groundwater as their potable water source. The prevalence of anemia is also high in this region, particularly among women. Moreover, arsenic is known to affect heme synthesis and erythrocytes and the risk of arsenic-induced skin lesions appears to differ by sex. Methods We conducted a case-control study in 147 arsenic-exposed Bangladeshi women to assess the association betwee...

  10. Nicotinamide Enhances Repair of Arsenic and Ultraviolet Radiation-Induced DNA Damage in HaCaT Keratinocytes and Ex Vivo Human Skin

    OpenAIRE

    Thompson, Benjamin C.; Halliday, Gary M.; Damian, Diona L

    2015-01-01

    Arsenic-induced skin cancer is a significant global health burden. In areas with arsenic contamination of water sources, such as China, Pakistan, Myanmar, Cambodia and especially Bangladesh and West Bengal, large populations are at risk of arsenic-induced skin cancer. Arsenic acts as a co-carcinogen with ultraviolet (UV) radiation and affects DNA damage and repair. Nicotinamide (vitamin B3) reduces premalignant keratoses in sun-damaged skin, likely by prevention of UV-induced cellular energy ...

  11. Nicotinamide Enhances Repair of Arsenic and Ultraviolet Radiation-Induced DNA Damage in HaCaT Keratinocytes and Ex Vivo Human Skin

    OpenAIRE

    Thompson, Benjamin C.; Halliday, Gary M.; Damian, Diona L.

    2015-01-01

    Arsenic-induced skin cancer is a significant global health burden. In areas with arsenic contamination of water sources, such as China, Pakistan, Myanmar, Cambodia and especially Bangladesh and West Bengal, large populations are at risk of arsenic-induced skin cancer. Arsenic acts as a co-carcinogen with ultraviolet (UV) radiation and affects DNA damage and repair. Nicotinamide (vitamin B3) reduces premalignant keratoses in sun-damaged skin, likely by prevention of UV-induced cellular energy ...

  12. A cross sectional study of anemia and iron deficiency as risk factors for arsenic-induced skin lesions in Bangladeshi women

    OpenAIRE

    Kile, Molly L; Faraj, Joycelyn M.; Ronnenberg, Alayne G; Quamruzzaman, Quazi; Rahman, Mahmudar; Mostofa, Golam; Afroz, Sakila; Christiani, David C.

    2016-01-01

    Background: In the Ganges Delta, chronic arsenic poisoning is a health concern affecting millions of people who rely on groundwater as their potable water source. The prevalence of anemia is also high in this region, particularly among women. Moreover, arsenic is known to affect heme synthesis and erythrocytes and the risk of arsenic-induced skin lesions appears to differ by sex. Methods: We conducted a case-control study in 147 arsenic-exposed Bangladeshi women to assess the association betw...

  13. Arsenic contamination in the Kanker district of central-east India: geology and health effects.

    Science.gov (United States)

    Pandey, P K; Sharma, R; Roy, M; Roy, S; Pandey, M

    2006-10-01

    This paper identifies newer areas of arsenic contamination in the District Kanker, which adjoins the District Rajnandgaon where high contamination has been reported earlier. A correlation with the mobile phase episodes of arsenic contamination has been identified, which further hinges on the complex geology of the area. Arsenic concentrations in both surface and groundwater, aquatic organisms (snail and water weeds) soil and vegetation of Kanker district and its adjoining area have been reported here. The region has been found to contain an elevated level of arsenic. All segments of the ecoysystem are contaminated with arsenic at varying degrees. The levels of arsenic vary constantly depending on the season and location. An analysis of groundwater from 89 locations in the Kanker district has shown high values of arsenic, iron and manganese (mean: 144, 914 and 371 microg L(-1), respectively). The surface water of the region shows elevated levels of arsenic, which is influenced by the geological mineralised zonation. The most prevalent species in the groundwater is As(III), whereas the surface water of the rivers shows a significant contamination with the As(V) species. The analysis shows a bio-concentration of the toxic metals arsenic, nickel, copper and chromium. Higher arsenic concentrations (groundwater concentrations greater than 50 microg L(-1)) are associated with sedimentary deposits derived from volcanic rocks, hence mineral leaching appears to be the source of arsenic contamination. Higher levels of arsenic and manganese in the Kanker district have been found to cause impacts on the flora and fauna. A case study of episodic arsenical diarrhoea is presented.

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

    Science.gov (United States)

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

    2014-12-01

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

  15. ARSENIC SPECIATION ANALYSIS IN HUMAN SALIVA

    Science.gov (United States)

    Background: Determination of arsenic species in human saliva is potentially useful for biomonitoring of human exposure to arsenic and for studying arsenic metabolism. However, there is no report on the speciation analysis of arsenic in saliva. Methods: Arsenic species in saliva ...

  16. ARSENIC SPECIATION ANALYSIS IN HUMAN SALIVA

    Science.gov (United States)

    Background: Determination of arsenic species in human saliva is potentially useful for biomonitoring of human exposure to arsenic and for studying arsenic metabolism. However, there is no report on the speciation analysis of arsenic in saliva. Methods: Arsenic species in saliva ...

  17. Arsenic biogeochemistry and human health risk assessment in organo-arsenical pesticide-applied acidic and alkaline soils: an incubation study.

    Science.gov (United States)

    Datta, Rupali; Sarkar, Dibyendu; Sharma, Saurabh; Sand, Kumarswamy

    2006-12-15

    Organo-arsenical compounds are considered non-carcinogenic, and hence, are still allowed by the regulatory agencies for use in agriculture as pesticides. Due to rapid encroachment of suburban areas into former agricultural lands, the potential for human exposure to soil-arsenic has increased tremendously in recent years. However, insufficient data is available on the stability of organo-arsenicals in soils; as to whether they remain in an organic form, or are converted over time to potentially carcinogenic inorganic forms. A static incubation study was conducted to estimate soil speciation and in-vitro bioavailability (i.e., bioaccessibility) of arsenic as a function of soil properties. Two chemically variant soil types were chosen, based on their potential differences with respect to arsenic reactivity: an acid sand with minimal arsenic retention capacity and an alkaline clay loam with relatively high concentrations of Fe/Al and Ca/Mg. The soils were amended with dimethylarsenic acid (DMA) at three rates, 45, 225 and 450 mg/kg, and incubated for 1 year. A sequential extraction scheme was employed to identify the geochemical forms of arsenic in soils, which were correlated with the in-vitro bioavailable fractions of arsenic. Human health risk calculated in terms of excess cancer risk (ECR) showed that risk assessment based on bioaccessible arsenic concentrations instead of the traditional total soil arsenic is a more realistic approach. Results showed that soil properties (such as pH, Fe/Al content and soil texture) of the two soils dictated the geochemical speciation, and hence, bioaccessibility of arsenic from DMA, indicating that the use of organic arsenicals as pesticides in mineral soils may not be a safe practice from a human health risk perspective.

  18. Modelling phytoremediation by the hyperaccumulating fern, Pteris vittata, of soils historically contaminated with arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Shelmerdine, Paula A.; Black, Colin R. [School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD (United Kingdom); McGrath, Steve P. [Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Young, Scott D., E-mail: scott.young@nottingham.ac.u [School of Biosciences, Biology Building, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2009-05-15

    Pteris vittata plants were grown on twenty-one UK soils contaminated with arsenic (As) from a wide range of natural and anthropogenic sources. Arsenic concentration was measured in fern fronds, soil and soil pore water collected with Rhizon samplers. Isotopically exchangeable soil arsenate was determined by equilibration with {sup 73}As{sup V}. Removal of As from the 21 soils by three sequential crops of P. vittata ranged between 0.1 and 13% of total soil As. Ferns grown on a soil subjected to long-term sewage sludge application showed reduced uptake of As because of high available phosphate concentrations. A combined solubility-uptake model was parameterised to enable prediction of phytoremediation success from estimates of soil As, 'As-lability' and soil pH. The model was used to demonstrate the remediation potential of P. vittata under different soil conditions and with contrasting assumptions regarding re-supply of the labile As pool from unavailable forms. - This paper presents a predictive model for phytoremediation of soils, historically contaminated with arsenic, by the hyperaccumulator P. vittata.

  19. Rock-Bound Arsenic Influences Ground Water and Sediment Chemistry Throughout New England

    Science.gov (United States)

    Robinson,, Gilpin R.; Ayotte, Joseph D.

    2007-01-01

    The information in this report was presented at the Northeastern Region Geological Society of America meeting held March 11-14, 2007, in Durham, New Hampshire. In the New England crystalline bedrock aquifer, concentrations of arsenic that exceed the drinking water standard of 10 ?g/L occur most frequently in ground water from wells sited in specific metamorphic and igneous rock units. Geochemical investigations indicate that these geologic units typically have moderately elevated whole-rock concentrations of arsenic compared to other rocks in the region. The distribution of ground water wells with As > 5 ?g/L has a strong spatial correlation with specific bedrock units where average whole-rock concentrations of arsenic exceed 1.1 mg/kg and where geologic and geochemical factors produce high pH ground water. Arsenic concentrations in stream sediments collected from small drainages reflect the regional distribution of this natural arsenic source and have a strong correlation with both rock chemistry and the distribution of bedrock units with elevated arsenic chemistry. The distribution of ground water wells with As > 5 ?g/L has a strong spatial correlation with the distribution of stream sediments where concentrations of arsenic exceed 6 mg/kg. Stream sediment chemistry also has a weak correlation with the distribution of agricultural lands where arsenical pesticides were used on apple, blueberry, and potato crops. Elevated arsenic concentrations in bedrock wells, however, do not correlate with agricultural areas where arsenical pesticides were used. These results indicate that both stream sediment chemistry and the solubility and mobility of arsenic in ground water in bedrock are influenced by host-rock arsenic concentrations. Stream sediment chemistry and the distribution of geologic units have been found to be useful parameters to predict the areas of greatest concern for elevated arsenic in ground water and to estimate the likely levels of human exposure to

  20. 40 CFR 61.184 - Ambient air monitoring for inorganic arsenic.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Ambient air monitoring for inorganic....184 Ambient air monitoring for inorganic arsenic. (a) The owner or operator of each source to which... arsenic concentrations in the ambient air. (b) The ambient air monitors shall be located at sites...

  1. ARSENIC REMOVAL TREATMENT OPTIONS FOR SINGLE FAMILY HOMES

    Science.gov (United States)

    The presentation provides information on POU and POE arsenic removal drinking water treatment systems. The presentation provides information on the arsenic rule, arsenic chemistry and arsenic treatment. The arsenic treatment options proposed for POU and POE treatment consist prim...

  2. Arsenic in drinking water and adverse birth outcomes in Ohio.

    Science.gov (United States)

    Almberg, Kirsten S; Turyk, Mary E; Jones, Rachael M; Rankin, Kristin; Freels, Sally; Graber, Judith M; Stayner, Leslie T

    2017-08-01

    Arsenic in drinking water has been associated with adverse reproductive outcomes in areas with high levels of naturally occurring arsenic. Less is known about the reproductive effects of arsenic at lower levels. This research examined the association between low-level arsenic in drinking water and small for gestational age (SGA), term low birth weight (term LBW), very low birth weight (VLBW), preterm birth (PTB), and very preterm birth (VPTB) in the state of Ohio. Exposure was defined as the mean annual arsenic concentration in drinking water in each county in Ohio from 2006 to 2008 using Safe Drinking Water Information System data. Birth outcomes were ascertained from the birth certificate records of 428,804 births in Ohio from the same time period. Multivariable generalized estimating equation logistic regression models were used to assess the relationship between arsenic and each birth outcome separately. Sensitivity analyses were performed to examine the roles of private well use and prenatal care utilization in these associations. Arsenic in drinking water was associated with increased odds of VLBW (AOR 1.14 per µg/L increase; 95% CI 1.04, 1.24) and PTB (AOR 1.10; 95% CI 1.06, 1.15) among singleton births in counties where water was positively associated with VLBW and PTB in a population where nearly all (>99%) of the population was exposed under the current maximum contaminant level of 10µg/L. Current regulatory standards may not be protective against reproductive effects of prenatal exposure to arsenic. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. The development of a realistic source term for sodium-cooled fast reactors : assessment of current status and future needs.

    Energy Technology Data Exchange (ETDEWEB)

    LaChance, Jeffrey L.; Phillips, Jesse; Parma, Edward J., Jr.; Olivier, Tara Jean; Middleton, Bobby D.

    2011-06-01

    Sodium-cooled fast reactors (SFRs) continue to be proposed and designed throughout the United States and the world. Although the number of SFRs actually operating has declined substantially since the 1980s, a significant interest in advancing these types of reactor systems remains. Of the many issues associated with the development and deployment of SFRs, one of high regulatory importance is the source term to be used in the siting of the reactor. A substantial amount of modeling and experimental work has been performed over the past four decades on accident analysis, sodium coolant behavior, and radionuclide release for SFRs. The objective of this report is to aid in determining the gaps and issues related to the development of a realistic, mechanistically derived source term for SFRs. This report will allow the reader to become familiar with the severe accident source term concept and gain a broad understanding of the current status of the models and experimental work. Further, this report will allow insight into future work, in terms of both model development and experimental validation, which is necessary in order to develop a realistic source term for SFRs.

  4. Estimation of marine source-term following Fukushima Dai-ichi accident.

    Science.gov (United States)

    Bailly du Bois, P; Laguionie, P; Boust, D; Korsakissok, I; Didier, D; Fiévet, B

    2012-12-01

    Contamination of the marine environment following the accident in the Fukushima Dai-ichi nuclear power plant represented the most important artificial radioactive release flux into the sea ever known. The radioactive marine pollution came from atmospheric fallout onto the ocean, direct release of contaminated water from the plant and transport of radioactive pollution from leaching through contaminated soil. In the immediate vicinity of the plant (less than 500 m), the seawater concentrations reached 68,000 Bq.L(-1) for (134)Cs and (137)Cs, and exceeded 100,000 Bq.L(-1) for (131)I in early April. Due to the accidental context of the releases, it is difficult to estimate the total amount of radionuclides introduced into seawater from data obtained in the plant. An evaluation is proposed here, based on measurements performed in seawater for monitoring purposes. Quantities of (137)Cs in seawater in a 50-km area around the plant were calculated from interpolation of seawater measurements. The environmental halftime of seawater in this area is deduced from the time-evolution of these quantities. This halftime appeared constant at about 7 days for (137)Cs. These data allowed estimation of the amount of principal marine inputs and their evolution in time: a total of 27 PBq (12 PBq-41 PBq) of (137)Cs was estimated up to July 18. Even though this main release may be followed by residual inputs from the plant, river runoff and leakage from deposited sediments, it represents the principal source-term that must be accounted for future studies of the consequences of the accident on marine systems. The (137)Cs from Fukushima will remain detectable for several years throughout the North Pacific, and (137)Cs/(134)Cs ratio will be a tracer for future studies.

  5. Inhalation Dose and Source Term Studies in a Tribal Area of Wayanad, Kerala, India

    Directory of Open Access Journals (Sweden)

    Reshma Bhaskaran

    2017-01-01

    Full Text Available Among radiation exposure pathways to human beings, inhalation dose is the most prominent one. Radon, thoron, and their progeny contribute more than 50 per cent to the annual effective dose due to natural radioactivity. South west coast of India is classified as a High Natural Background Radioactivity Area and large scale data on natural radioactivity and dosimetry are available from these coastal regions including the Neendakara-Chavara belt in the south of Kerala. However, similar studies and reports from the northern part of Kerala are scarce. The present study involves the data collection and analysis of radon, thoron, and progeny concentration in the Wayanad district of Kerala. The radon concentration was found to be within a range of 12–378 Bq/m3. The thoron concentration varied from 15 to 621 Bq/m3. Progeny concentration of radon and thoron and the diurnal variation of radon were also studied. In order to assess source term, wall and floor exhalation studies have been done for the houses showing elevated concentration of radon and thoron. The average values of radon, thoron, and their progeny are found to be above the Indian average as well as the average values reported from the High Natural Background Radioactivity Areas of Kerala. Exhalation studies of the soil samples collected from the vicinity of the houses show that radon mass exhalation rate varied from below detectable limit (BDL to a maximum of 80 mBq/kg/h. The thoron surface exhalation rate ranged from BDL to 17470 Bq/m2/h.

  6. Biomarkers of exposure, effect, and susceptibility of arsenic-induced health hazards in Taiwan.

    Science.gov (United States)

    Chen, Chien-Jen; Hsu, Lin-I; Wang, Chih-Hao; Shih, Wei-Liang; Hsu, Yi-Hsiang; Tseng, Mei-Ping; Lin, Yu-Chun; Chou, Wei-Ling; Chen, Chia-Yen; Lee, Cheng-Yeh; Wang, Li-Hua; Cheng, Yu-Chin; Chen, Chi-Ling; Chen, Shu-Yuan; Wang, Yuan-Hung; Hsueh, Yu-Mei; Chiou, Hung-Yi; Wu, Meei-Maan

    2005-08-07

    Long-term exposure to inorganic arsenic from drinking water has been documented to induce cancers and vascular diseases in a dose-response relationship. A series of molecular environmental epidemiological studies have been carried out to elucidate biomarkers of exposure, effect, and susceptibility for arsenic-related health hazards in Taiwan. Arsenic levels in urine, hair, and nail are biomarkers for short-term (changes including sister chromatid exchange, micronuclei, and chromosome aberrations of peripheral lymphocytes. Both mutation type and hot spots of p53 gene were significantly different in arsenic-induced and non-arsenic-induced TCCs. The frequency of chromosomal imbalances analyzed by comparative genomic hybridization and the frequency of loss of heterozygosity were significantly higher in arsenic-induced TCC than non-arsenic-induced TCC at specific sites. Biomarkers of susceptibility to arsenic-induced health hazards included genetic polymorphisms of enzymes involved in xenobiotic metabolism, DNA repair, and oxidative stress, as well as serum level of carotenoids. Gene-gene and gene-environment interactions are involved in arsenic-induced health hazards through toxicological mechanisms including genomic instability and oxidative stress.

  7. Arsenic and other oxyanion-forming trace elements in an alluvial basin aquifer: Evaluating sources and mobilization by isotopic tracers (Sr, B, S, O, H, Ra)

    Energy Technology Data Exchange (ETDEWEB)

    Vinson, David S., E-mail: dsv3@duke.edu [Duke University, Division of Earth and Ocean Sciences, Box 90227, Durham, NC 27708 (United States); McIntosh, Jennifer C. [University of Arizona, Department of Hydrology and Water Resources, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States); Dwyer, Gary S.; Vengosh, Avner [Duke University, Division of Earth and Ocean Sciences, Box 90227, Durham, NC 27708 (United States)

    2011-08-15

    Highlights: > Elevated natural As and F occur in the Willcox Basin aquifer of Arizona. > Oxyanion-forming elements are derived from volcanic-source aquifer sediments. > Sr isotopes trace sediment sources linked to oxyanion-forming trace elements. > {sup 87}Sr/{sup 86}Sr > 0.720 indicates Proterozoic crystalline-source sediment contributing low As. > Both sediment source and hydrogeochemical evolution (Ca/Na) affect As levels. - Abstract: The Willcox Basin is a hydrologically closed basin in semi-arid southeastern Arizona (USA) and, like many other alluvial basins in the southwestern USA, is characterized by oxic, near-neutral to slightly basic groundwater containing naturally elevated levels of oxyanion-forming trace elements such as As. This study evaluates the sources and mobilization of these oxyanionic trace elements of health significance by using several isotopic tracers of water-rock interaction and groundwater sources ({sup 87}Sr/{sup 86}Sr, {delta}{sup 34}S{sub SO4}, {delta}{sup 11}B, {delta}{sup 2}H, {delta}{sup 18}O, {sup 3}H). Values of {delta}{sup 2}H (-85 per mille to -64 per mille) and {delta}{sup 18}O (-11.8 per mille to -8.6 per mille) are consistent with precipitation and groundwater in adjacent alluvial basins, and low to non-detectable {sup 3}H activities further imply that modern recharge is slow in this semi-arid environment. Large variations in {sup 87}Sr/{sup 86}Sr ratios imply that groundwater has interacted with multiple sediment sources that constitute the basin-fill aquifer, including Tertiary felsic volcanic rocks, Paleozoic sedimentary rocks, and Proterozoic crystalline rocks. In general, low concentrations of oxyanion-forming trace elements and F{sup -} are associated with a group of waters exhibiting highly radiogenic values of {sup 87}Sr/{sup 86}Sr (0.72064-0.73336) consistent with waters in Proterozoic crystalline rocks in the mountain blocks (0.73247-0.75010). Generally higher As concentrations (2-29 {mu}g L{sup -1}), other

  8. Case reports: arsenic pollution in Thailand, Bangladesh, and Hungary.

    Science.gov (United States)

    Jones, Huw; Visoottiviseth, Pornsawan; Bux, M Khoda; Födényi, Rita; Kováts, Nora; Borbély, Gábor; Galbács, Zoltán

    2008-01-01

    Although arsenic contamination in the three countries described herein differs, a number of common themes emerge. In each country, the presence of arsenic is both long term and of geological origin. Moreover, in each of these countries, arsenic was only recently discovered to be a potential public health problem, having been first formally recognized in the 1980s or 1990s. In Bangledesh, exposure of the public to arsenic arose as a result of the search for microbially safe drinking water; this search resulted in the sinking of tube wells into aquifers. In Hungary, the natural bedrock geology was responsible for contamination of aquifer water. The genesis of arsenic contamination in Thailand arose primarily from small-scale alluvial mining activities, which mobilized geologically bound arsenic. Because of the complex chemistry of arsenic, and variability in where it is found and how it is bound, multiple mitigation methods must be considered for mitigating episodes of environmental contamination. The Ron Phibun region of Thailand has a 100-yr history of tin mining. A geological survey of the region was conducted in the mid-1990s by the Department of Mineral Resources and Department of Industry of Thailand, and was supported by the British Geological Society. Skin cancer in Thailand was first reported in 1987, in the southern part of the country; among other symptoms observed, there was evidence of IQ diminutions among the population. Arsenic water levels to 9,000 pg/L were reported; such levels are substantially above any guideline levels. A long-term plan to mitigate arsenic contamination was devised in 1998-2000. The plan involved removal of arsenic-contaminated land and improved management of mining wastes. However, at $22 million, the cost was deemed prohibitive for the regional Thai economy. An alternative solution of providing pipeline drinking water to the exposed population was also unsuccessful, either because arsenic contamination levels did not fall

  9. Construction of a modular arsenic resistance operon in E. coli and the production of arsenic nanoparticles

    Directory of Open Access Journals (Sweden)

    Matthew Charles Edmundson

    2015-10-01

    Full Text Available Arsenic is a widespread contaminant of both land and water around the world. Current methods of decontamination such as phytoremediation and chemical adsorbents can be resource and time intensive, and may not be suitable for some areas such as remote communities where cost and transportation are major issues. Bacterial decontamination, with strict controls preventing environmental release, may offer a cost-effective alternative or provide a financial incentive when used in combination with other remediation techniques. In this study we have produced E. coli strains containing arsenic resistance genes from a number of sources, overexpressing them and testing their effects on arsenic resistance. While the lab E. coli strain JM109 (the wild-type is resistant up to 20 mM sodium arsenate the strain containing our plasmid pEC20 is resistant up to 80 mM. When combined with our construct pArsRBCC arsenic-containing nanoparticles were observed at the cell surface; the elements of pEC20 and pArsRBCC were therefore combined in a modular construct, pArs, in order to evaluate the roles and synergistic effects of the components of the original plasmids in arsenic resistance and nanoparticle formation. We also investigated the use of introducing the lac operator in order to more tightly control expression from pArs. We demonstrate that our strains are able to reduce toxic forms of arsenic into stable, insoluble metallic As(0, providing one way to remove arsenate contamination, and which may also be of benefit for other heavy metals.

  10. Occurrence and geochemical behavior of arsenic in a coastal aquifer-aquitard system of the Pearl River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ya [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Jiao, Jiu Jimmy, E-mail: jjiao@hku.hk [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Cherry, John A. [School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

    2012-06-15

    Elevated concentrations of arsenic, up to 161 {mu}g/L, have been identified in groundwater samples from the confined basal aquifer underlying the aquitard of the Pearl River Delta (PRD). Both aquatic arsenic in pore water and solid arsenic in the sediments in the basal aquifer and aquitard were identified. Arsenic speciation of groundwater in the basal aquifer was elucidated on a pH-Eh diagram. In the PRD, arsenic is enriched in groundwater having both low and high salinity, and arsenic enriched groundwater is devoid of dissolved oxygen, has negative Eh values, is slightly alkaline, and has abnormally high concentrations of ammonium and dissolved organic carbon, but low concentrations of nitrate and nitrite. Results of geochemical and hydrochemical analyses and sequential extraction analysis suggest that reductive dissolution of iron oxyhydroxide could be one of the important processes that mobilized solid arsenic. We speculate that mineralization of sedimentary organic matter could also contribute to aquatic arsenic. Scanning electron microscope analysis confirms that abundant authigenic pyrite is present in the sediments. Sulphate derived from paleo-seawater served as the important sulfur source for authigenic pyrite formation. Co-precipitation of arsenic with authigenic pyrite significantly controlled concentrations of aquatic arsenic in the coastal aquifer-aquitard system. - Highlights: Black-Right-Pointing-Pointer Coastal aquifer and aquitard are treated as an integrate system. Black-Right-Pointing-Pointer Both aquatic arsenic and solid arsenic are observed. Black-Right-Pointing-Pointer Aquatic arsenic is derived from reductive dissolution of iron oxyhydroxide. Black-Right-Pointing-Pointer Aquatic arsenic can also derived from mineralization of sedimentary organic matter. Black-Right-Pointing-Pointer Co-precipitation of arsenic with authigenic pyrite is significant in such a system.

  11. Linking geochemical processes in mud volcanoes with arsenic mobilization driven by organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chia-Chuan; Kar, Sandeep [Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan (China); Jean, Jiin-Shuh, E-mail: jiinshuh@mail.ncku.edu.tw [Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan (China); Wang, Chung-Ho [Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan (China); Lee, Yao-Chang [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China); Sracek, Ondra [OPV s.r.o. (Groundwater Protection Ltd.), Bělohorská 31, 169 00 Praha 6 (Czech Republic); Department of Geology, Faculty of Science, Palacký University, 17. listopadu 12, 771 46 Olomouc (Czech Republic); Li, Zhaohui [Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan (China); Department of Geosciences, University of Wisconsin – Parkside, Kenosha, WI 53144 (United States); Bundschuh, Jochen [Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan (China); Faculty of Engineering and Surveying and National Centre for Engineering in Agriculture, The University of Southern Queensland, Toowoomba (Australia); Yang, Huai-Jen [Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan (China); Chen, Chien-Yen [Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi 621, Taiwan (China)

    2013-11-15

    Highlights: ► Study represents geochemical characteristics and their spatial variability among six mud volcanoes of southern Taiwan. ► Anoxic mud volcanic fluids containing high NaCl imply connate water as the possible source. ► δ{sup 18}O-rich fluids is associated with silicate and carbonate mineral released through water–rock interaction. ► High As content in mud and its sequential extraction showed mostly adsorbed As on organic and sulphidic phases. ► Organic matter specially humic acid showed redox dependence and it may play an important role in binding and mobility of arsenic. -- Abstract: The present study deals with geochemical characterization of mud fluids and sediments collected from Kunshuiping (KSP), Liyushan (LYS), Wushanting (WST), Sinyangnyuhu (SYNH), Hsiaokunshui (HKS) and Yenshuikeng (YSK) mud volcanoes in southwestern Taiwan. Chemical constituents (cations, anions, trace elements, organic carbon, humic acid, and stable isotopes) in both fluids and mud were analyzed to investigate the geochemical processes and spatial variability among the mud volcanoes under consideration. Analytical results suggested that the anoxic mud volcanic fluids are highly saline, implying connate water as the probable source. The isotopic signature indicated that δ{sup 18}O-rich fluids may be associated with silicate and carbonate mineral released through water–rock interaction, along with dehydration of clay minerals. Considerable amounts of arsenic in mud irrespective of fluid composition suggested possible release through biogeochemical processes in the subsurface environment. Sequential extraction of As from the mud indicated that As was mostly present in organic and sulphidic phases, and adsorbed on amorphous Mn oxyhydroxides. Volcanic mud and fluids are rich in organic matter (in terms of organic carbon), and the presence of humic acid in mud has implications for the binding of arsenic. Functional groups of humic acid also showed variable sources of

  12. Arsenic in shrimp from Kuwait

    Energy Technology Data Exchange (ETDEWEB)

    Bou-Olayan, A.H. [Kuwait Univ. (Kuwait); Al-Yakoob, S.; Al-Hossaini, M. [Kuwait Institute for Scientific Research (Kuwait)

    1995-04-01

    Arsenic is ubiquitous in the environment and can accumulate in food via contaminated soil, water or air. It enters the food chain through dry and wet atmospheric deposition. Combustion of oil and coal, use of arsenical fertilizers and pesticides and smelting of ores contributes significantly to the natural background of arsenic in soils and sediments. The metal can be transferred from soil to man through plants. In spite of variation in acute, subacute, and chronic toxic effects to plants and animals, evidence of nutritional essentiality of arsenic for rats, goats, and guinea pigs has been suggested, but has not been confirmed for humans. Adverse toxic effects of arsenic as well as its widespread distribution in the environment raises concern about levels of arsenic in man`s diet. Higher levels of arsenic in the diet can result in a higher accumulation rate. Arsenic levels in marine organisms are influenced by species differences, size of organism, and human activities. Bottom dwellers such as shrimp, crab, and lobster accumulate more arsenic than fish due to their frequent contact with bottom sediments. Shrimp constitute approximately 30% of mean total seafood consumption in Kuwait. This study was designed to determine the accumulation of arsenic in the commercially important jinga shrimp (Metapenaeus affinis) and grooved tiger prawn (Penaeus semisulcatus). 13 refs., 3 figs., 1 tab.

  13. Arsenic and fluoride in the groundwater of Mexico.

    Science.gov (United States)

    Armienta, M A; Segovia, N

    2008-08-01

    Concentrations of arsenic and fluoride above Mexican drinking water standards have been detected in aquifers of various areas of Mexico. This contamination has been found to be mainly caused by natural sources. However, the specific processes releasing these toxic elements into groundwater have been determined in a few zones only. Many studies, focused on arsenic-related health effects, have been performed at Comarca Lagunera in northern México. High concentrations of fluoride in water were also found in this area. The origin of the arsenic there is still controversial. Groundwater in active mining areas has been polluted by both natural and anthropogenic sources. Arsenic-rich minerals contaminate the fractured limestone aquifer at Zimapán, Central México. Tailings and deposits smelter-rich fumes polluted the shallow granular aquifer. Arsenic contamination has also been reported in the San Antonio-El Triunfo mining zone, southern Baja California, and Santa María de la Paz, in San Luis Potosí state. Even in the absence of mining activities, hydrogeochemistry and statistical techniques showed that arsenopyrite oxidation may also contaminate water, as in the case of the Independencia aquifer in the Mexican Altiplano. High concentrations of arsenic have also been detected in geothermal areas like Los Azufres, Los Humeros, and Acoculco. Prevalence of dental fluorosis was revealed by epidemiological studies in Aguascalientes and San Luis Potosí states. Presence of fluoride in water results from dissolution of acid-volcanic rocks. In Mexico, groundwater supplies most drinking water. Current knowledge and the geology of Mexico indicate the need to include arsenic and fluoride determinations in groundwater on a routine basis, and to develop interdisciplinary studies to assess the contaminant's sources in all enriched areas.

  14. Nonradioactive Environmental Emissions Chemical Source Term for the Double Shell Tank (DST) Vapor Space During Waste Retrieval Operations

    Energy Technology Data Exchange (ETDEWEB)

    MAY, T.H.

    2000-04-21

    A nonradioactive chemical vapor space source term for tanks on the Phase 1 and the extended Phase 1 delivery, storage, and disposal mission was determined. Operations modeled included mixer pump operation and DST waste transfers. Concentrations of ammonia, specific volatile organic compounds, and quantitative volumes of aerosols were estimated.

  15. Determination of a source term for a time fractional diffusion equation with an integral type over-determining condition

    Directory of Open Access Journals (Sweden)

    Timurkhan S. Aleroev

    2013-12-01

    Full Text Available We consider a linear heat equation involving a fractional derivative in time, with a nonlocal boundary condition. We determine a source term independent of the space variable, and the temperature distribution for a problem with an over-determining condition of integral type. We prove the existence and uniqueness of the solution, and its continuous dependence on the data.

  16. Arsenic incorporation into authigenic pyrite, Bengal Basin sediment, Bangladesh

    Science.gov (United States)

    Lowers, H.A.; Breit, G.N.; Foster, A.L.; Whitney, J.; Yount, J.; Uddin, Md. N.; Muneem, Ad. A.

    2007-01-01

    Sediment from two deep boreholes (???400 m) approximately 90 km apart in southern Bangladesh was analyzed by X-ray absorption spectroscopy (XAS), total chemical analyses, chemical extractions, and electron probe microanalysis to establish the importance of authigenic pyrite as a sink for arsenic in the Bengal Basin. Authigenic framboidal and massive pyrite (median values 1500 and 3200 ppm As, respectively), is the principal arsenic residence in sediment from both boreholes. Although pyrite is dominant, ferric oxyhydroxides and secondary iron phases contain a large fraction of the sediment-bound arsenic between approximately 20 and 100 m, which is the depth range of wells containing the greatest amount of dissolved arsenic. The lack of pyrite in this interval is attributed to rapid sediment deposition and a low sulfur flux from riverine and atmospheric sources. The ability of deeper aquifers (>150 m) to produce ground water with low dissolved arsenic in southern Bangladesh reflects adequate sulfur supplies and sufficient time to redistribute the arsenic into pyrite during diagenesis.

  17. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources

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    Vandana S

    2010-01-01

    Full Text Available Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR -1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR of a reference 137 Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference 137 Cs brachytherapy source (CDCSJ5, and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA, Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference 137 Cs source. All required correction factors were applied in the calculation of the RAKR of the 137 Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within ±0.5% for about three years after calibration/recalibration. However, it shows deviations larger than ±0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  18. Long term response stability of a well-type ionization chamber used in calibration of high dose rate brachytherapy sources.

    Science.gov (United States)

    Vandana, S; Sharma, S D

    2010-04-01

    Well-type ionization chamber is often used to measure strength of brachytherapy sources. This study aims to check long term response stability of High Dose Rate (HDR)-1000 Plus well-type ionization chamber in terms of reference air kerma rate (RAKR) of a reference (137)Cs brachytherapy source and recommend an optimum frequency of recalibration. An HDR-1000 Plus well-type ionization chamber, a reference (137)Cs brachytherapy source (CDCSJ5), and a MAX-4000 electrometer were used in this study. The HDR-1000 Plus well-type chamber was calibrated in terms of reference air kerma rate by the Standards Laboratory of the International Atomic Energy Agency (IAEA), Vienna. The response of the chamber was verified at regular intervals over a period of eight years using the reference (137)Cs source. All required correction factors were applied in the calculation of the RAKR of the (137)Cs source. This study reveals that the response of the HDR-1000 Plus well-type chamber was well within +/-0.5% for about three years after calibration/recalibration. However, it shows deviations larger than +/-0.5% after three years of calibration/recalibration and the maximum variation in response of the chamber during an eight year period was 1.71%. The optimum frequency of recalibration of a high dose rate well-type chamber should be three years.

  19. Rural methods to mitigate arsenic contaminated water

    OpenAIRE

    Parajuli, Krishna

    2013-01-01

    Consumption of arsenic contaminated water is one of the burning issues in the rural world. Poor public awareness program about health effects of drinking arsenic contaminated water and the rural methods to mitigate this problem poses a great threat of arsenic poisoning many people of the rural world. In this thesis, arsenic removal efficiency and the working mechanism of four rural and economical arsenic mitigation technologies i.e. solar oxidation and reduction of arsenic (SORAS), Bucket tr...

  20. Source term derivation and radiological safety analysis for the TRICO II research reactor in Kinshasa

    Energy Technology Data Exchange (ETDEWEB)

    Muswema, J.L., E-mail: jeremie.muswem@unikin.ac.cd [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Ekoko, G.B. [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Lukanda, V.M. [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Democratic Republic of the Congo' s General Atomic Energy Commission, P.O. Box AE1 (Congo, The Democratic Republic of the); Lobo, J.K.-K. [Faculty of Science, University of Kinshasa, P.O. Box 190, KIN XI (Congo, The Democratic Republic of the); Darko, E.O. [Radiation Protection Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Boafo, E.K. [University of Ontario Institute of Technology, 2000 Simcoe St. North, Oshawa, ONL1 H7K4 (Canada)

    2015-01-15

    Highlights: • Atmospheric dispersion modeling for two credible accidents of the TRIGA Mark II research reactor in Kinshasa (TRICO II) was performed. • Radiological safety analysis after the postulated initiating events (PIE) was also carried out. • The Karlsruhe KORIGEN and the HotSpot Health Physics codes were used to achieve the objectives of this study. • All the values of effective dose obtained following the accident scenarios were below the regulatory limits for reactor staff members and the public, respectively. - Abstract: The source term from the 1 MW TRIGA Mark II research reactor core of the Democratic Republic of the Congo was derived in this study. An atmospheric dispersion modeling followed by radiation dose calculation were performed based on two possible postulated accident scenarios. This derivation was made from an inventory of peak radioisotope activities released in the core by using the Karlsruhe version of isotope generation code KORIGEN. The atmospheric dispersion modeling was performed with HotSpot code, and its application yielded to radiation dose profile around the site using meteorological parameters specific to the area under study. The two accident scenarios were picked from possible accident analyses for TRIGA and TRIGA-fueled reactors, involving the case of destruction of the fuel element with highest activity release and a plane crash on the reactor building as the worst case scenario. Deterministic effects of these scenarios are used to update the Safety Analysis Report (SAR) of the reactor, and for its current version, these scenarios are not yet incorporated. Site-specific meteorological conditions were collected from two meteorological stations: one installed within the Atomic Energy Commission and another at the National Meteorological Agency (METTELSAT), which is not far from the site. Results show that in both accident scenarios, radiation doses remain within the limits, far below the recommended maximum effective

  1. Utility of arsenic-treated bird skins for DNA extraction

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    Gamauf Anita

    2011-06-01

    Full Text Available Abstract Background Natural history museums receive a rapidly growing number of requests for tissue samples from preserved specimens for DNA-based studies. Traditionally, dried vertebrate specimens were treated with arsenic because of its toxicity and insect-repellent effect. Arsenic has negative effects on in vivo DNA repair enzymes and consequently may inhibit PCR performance. In bird collections, foot pad samples are often requested since the feet were not regularly treated with arsenic and because they are assumed to provide substantial amounts of DNA. However, the actual influence of arsenic on DNA analyses has never been tested. Findings PCR success of both foot pad and body skin samples was significantly lower in arsenic-treated samples. In general, foot pads performed better than body skin samples. Moreover, PCR success depends on collection date in which younger samples yielded better results. While the addition of arsenic solution to the PCR mixture had a clear negative effect on PCR performance after the threshold of 5.4 μg/μl, such high doses of arsenic are highly unlikely to occur in dried zoological specimens. Conclusions While lower PCR success in older samples might be due to age effects and/or DNA damage through arsenic treatment, our results show no inhibiting effect on DNA polymerase. We assume that DNA degradation proceeds more rapidly in thin tissue layers with low cell numbers that are susceptible to external abiotic influences. In contrast, in thicker parts of a specimen, such as foot pads, the outermost horny skin may act as an additional barrier. Since foot pads often performed better than body skin samples, the intention to preserve morphologically important structures of a specimen still conflicts with the aim to obtain optimal PCR success. Thus, body skin samples from recently collected specimens should be considered as alternative sources of DNA.

  2. Bioaccessibility of lead and arsenic in traditional Indian medicines.

    Science.gov (United States)

    Koch, Iris; Moriarty, Maeve; House, Kim; Sui, Jie; Cullen, William R; Saper, Robert B; Reimer, Kenneth J

    2011-10-01

    Arsenic and lead have been found in a number of traditional Ayurvedic medicines, and the practice of Rasa Shastra (combining herbs with metals, minerals and gems), or plant ingredients that contain these elements, may be possible sources. To obtain an estimate of arsenic and lead solubility in the human gastrointestinal tract, bioaccessibility of the two elements was measured in 42 medicines, using a physiologically-based extraction test. The test consisted of a gastric phase at pH 1.8 containing organic acids, pepsin and salt, followed by an intestinal phase, at pH 7 and containing bile and pancreatin. Arsenic speciation was measured in a subset of samples that had sufficiently high arsenic concentrations for the X-ray absorption near edge structure analysis used. Bioaccessible lead was found in 76% of samples, with a large range of bioaccessibility results, but only 29% of samples had bioaccessible arsenic. Lead bioaccessibility was high (close to 100%) in a medicine (Mahayograj Guggulu) that had been compounded with bhasmas (calcined minerals), including naga (lead) bhasma. For the samples in which arsenic speciation was measured, bioaccessible arsenic was correlated with the sum of As(V)-O and As(III)-O and negatively correlated with As-S. These results suggest that the bioaccessible species in the samples had been oxidized from assumed As-S raw medicinal ingredients (realgar, As(4)S(4), added to naga (lead) bhasma and As(III)-S species in plants). Consumption at recommended doses of all medicines with bioaccessibile lead or arsenic would lead to the exceedance of at least one standard for acceptable daily intake of toxic elements. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  3. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

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    Sayedur Rahman Chowdhury

    2012-12-01

    Full Text Available Arsenic (As causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues.

  4. Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh

    Science.gov (United States)

    Jiang, Jia-Qian; Ashekuzzaman, S. M.; Jiang, Anlun; Sharifuzzaman, S. M.; Chowdhury, Sayedur Rahman

    2012-01-01

    Arsenic (As) causes health concerns due to its significant toxicity and worldwide presence in drinking water and groundwater. The major sources of As pollution may be natural process such as dissolution of As-containing minerals and anthropogenic activities such as percolation of water from mines, etc. The maximum contaminant level for total As in potable water has been established as 10 µg/L. Among the countries facing As contamination problems, Bangladesh is the most affected. Up to 77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water. Therefore, it has become an urgent need to provide As-free drinking water in rural households throughout Bangladesh. This paper provides a comprehensive overview on the recent data on arsenic contamination status, its sources and reasons of mobilization and the exposure pathways in Bangladesh. Very little literature has focused on the removal of As from groundwaters in developing countries and thus this paper aims to review the As removal technologies and be a useful resource for researchers or policy makers to help identify and investigate useful treatment options. While a number of technological developments in arsenic removal have taken place, we must consider variations in sources and quality characteristics of As polluted water and differences in the socio-economic and literacy conditions of people, and then aim at improving effectiveness in arsenic removal, reducing the cost of the system, making the technology user friendly, overcoming maintenance problems and resolving sludge management issues. PMID:23343979

  5. Arsenic release metabolically limited to permanently water-saturated soil in Mekong Delta

    Science.gov (United States)

    Stuckey, Jason W.; Schaefer, Michael V.; Kocar, Benjamin D.; Benner, Shawn G.; Fendorf, Scott

    2016-01-01

    Microbial reduction of arsenic-bearing iron oxides in the deltas of South and Southeast Asia produces widespread arsenic-contaminated groundwater. Organic carbon is abundant both at the surface and within aquifers, but the source of organic carbon used by microbes in the reduction and release of arsenic has been debated, as has the wetland type and sedimentary depth where release occurs. Here we present data from fresh-sediment incubations, in situ model sediment incubations and a controlled field experiment with manipulated wetland hydrology and organic carbon inputs. We find that in the minimally disturbed Mekong Delta, arsenic release is limited to near-surface sediments of permanently saturated wetlands where both organic carbon and arsenic-bearing solids are sufficiently reactive for microbial oxidation of organic carbon and reduction of arsenic-bearing iron oxides. In contrast, within the deeper aquifer or seasonally saturated sediments, reductive dissolution of iron oxides is observed only when either more reactive exogenous forms of iron oxides or organic carbon are added, revealing a potential thermodynamic restriction to microbial metabolism. We conclude that microbial arsenic release is limited by the reactivity of arsenic-bearing iron oxides with respect to native organic carbon, but equally limited by organic carbon reactivity with respect to the native arsenic-bearing iron oxides.

  6. Arsenic exposure disrupts the normal function of the FA/BRCA repair pathway.

    Science.gov (United States)

    Peremartí, Jana; Ramos, Facundo; Marcos, Ricard; Hernández, Alba

    2014-11-01

    Chronic arsenic exposure is known to enhance the genotoxicity/carcinogenicity of other DNA-damaging agents by inhibiting DNA repair activities. Interference with nucleotide excision repair and base excision repair are well documented, but interactions with other DNA repair pathways are poorly explored so far. The Fanconi anemia FA/BRCA pathway is a DNA repair mechanism required for maintaining genomic stability and preventing cancer. Here, interactions between arsenic compounds and the FA/BRCA pathway were explored by using isogenic FANCD2(-/-) (FA/BRCA-deficient) and FANCD2(+/+) (FA/BRCA-corrected) human fibroblasts. To study whether arsenic disrupts the normal FA/BRCA function, FANCD2(+/+) cells were preexposed to subtoxic concentrations of the trivalent arsenic compounds methylarsonous acid (MMA(III)) and arsenic trioxide (ATO) for 2 weeks. The cellular response to mitomicin-C, hydroxyurea, or diepoxybutane, typical inducers of the studied pathway, was then evaluated and compared to that of FANCD2(-/-) cells. Our results show that preexposure to the trivalent arsenicals MMA(III) and ATO induces in corrected cells, a cellular FA/BRCA-deficient phenotype characterized by hypersensitivity, enhanced accumulation in the G2/M compartment and increased genomic instability--measured as micronuclei. Overall, our data demonstrate that environmentally relevant arsenic exposures disrupt the normal function of the FA/BRCA activity, supporting a novel source of arsenic co- and carcinogenic effects. This is the first study linking arsenic exposure with the FA/BRCA DNA repair pathway.

  7. Arsenic oxidation capabilities of a chemoautotrophic bacterial population: Use for the treatment of an arsenic contaminated wastewater

    Science.gov (United States)

    Dictor, M.-C.; Battaglia-Brunet, F.; Garrido, F.; Baranger, P.

    2003-05-01

    An autotrophic bacterial population, named CAsOl, able to oxidise arsenic has been isolated from a former gold mine (Saint-Yrieix, France). This bacterial population was composed of two microorganisms: a bacterial strain close to Ralstonia picketii and the second one related to Thiomonas genus (identification by 16S rDNA sequencing). This microbial consortium was able to oxidise arsenic with CO2 as the carbon source, arsenite as electron donor and oxygen as electron accepter. A significant oxidising activity was observed in a pH range comprised between 3 to 8 (pH optimum 5 7). A laboratory experiment for the biological treatment of a synthetic effluent containing 100 mg.L^{-1} of arsenic has been carried out. A mineral support, pouzzolana, has been colonised by the population CAsOl and the column was fed continuously with a synthetic medium in order to determine the maximal arsenic oxidation rate and the optimal residence time. In our experimental conditions, the maximum arsenic oxidation rate was 3,9 g As(Ill). L^{-1}.day^{-1} with a residence time of 1 hour after 55 days of continuous running. The performance of our bacterial population for arsenite oxidation in arsenic contaminated wastewater are especially important in the case of a treatment of arsenious wastewater as it presents advantages compared to physico-chemical treatments (consumption and cost of chemicals, potential toxic by-products generation...).

  8. [Inventories of atmospheric arsenic emissions from coal combustion in China, 2005].

    Science.gov (United States)

    Tian, He-Zhong; Qu, Yi-Ping

    2009-04-15

    Anthropogenic arsenic (As) emitted from coal combustion is one of key trace elements leading to negative air pollution and national economy loss. It is of great significance to estimate the atmospheric arsenic emission for proposing relevant laws or regulations and selecting proper pollution control technologies. The inventories of atmospheric arsenic emissions from coal combustion in China were evaluated by adopting the emission factor method based on fuel consumption. Arsenic emission sources were firstly classified into several categories by economic sectors, combustion types and pollution control technologies. Then, according to provincial coal consumption and averaged arsenic concentration in the feed fuel, the inventories of atmospheric arsenic emission from coal combustion in China in 2005 were established. Coal outputand consumption in China in 2005 were 2,119.8 and 2,099.8 Mt, respectively. The total emissions of arsenic released into the atmosphere in 2005 in China were estimated at about 1,564.4 t, and Shandong ranked the largest province with 144.4 t arsenic release, followed by Hunan (141.1 t), Hebei (108.5 t), Henan (77.7 t), and Jiangsu (77.0 t), which were mainly concentrated in the eastern and central provinces of China. The arsenic emissions were largely emitted by industry sector (818.8 t) and thermal power generation sector (303.4 t), contributing 52.3% and 19.4% of the totals, respectively. About 375.5 t arsenic was estimated to be released into the atmosphere in the form of gas phase in China in 2005, with a share of 24% of the totals. In general, arsenic pollution control from coal combustion should be highlighted for the power and industry sectors in the whole country. However, arsenic poisoning caused by residential coal burning should also be paid great attention in some areas such as Xinjiang, Gansu, Qinghai and Guishou.

  9. Arsenic transformation and mobilization from minerals by the arsenite oxidizing strain WAO

    Science.gov (United States)

    Rhine, E.D.; Onesios, K.M.; Serfes, M.E.; Reinfelder, J.R.; Young, L.Y.

    2008-01-01

    Analysis of arsenic concentrations in New Jersey well water from the Newark Basin showed up to 15% of the wells exceed 10 ??g L-1, with a maximum of 215 ??g L-1. In some geologic settings in the basin, this mobile arsenic could be from the weathering of pyrite (FeS2) found in black shale that contains up to 4% arsenic by weight. We hypothesized that under oxic conditions at circumneutral pH, the microbially mediated oxidation of sulfide in the pyrite lattice would lead to the release of pyrite-bound arsenic. Moreover, the oxidation of aqueous As(III) to As(V) by aerobic microorganisms could further enhance arsenic mobilization from the solid phase. Enrichment cultures under aerobic, As(III)-oxidizing conditions were established under circumneutral pH with weathered black shale from the Newark Basin as the inoculum source. Strain WAO, an autotrophic inorganic-sulfur and As(III)-oxidizer, was isolated and phylogenetically and physiologically characterized. Arsenic mobilization studies from arsenopyrite (FeAsS) mineral, conducted with strain WAO at circumneutral pH, showed microbially enhanced mobilization of arsenic and complete oxidation of released arsenic and sulfur to stoichiometric amounts of arsenate and sulfate. In addition, WAO preferentially colonized pyrite on the surface of arsenic-bearing, black shale thick sections. These findings support the hypothesis that microorganisms can directly mobilize and transform arsenic bound in mineral form at circumneutral pH and suggest that the microbial mobilization of arsenic into groundwater may be important in other arsenic-impacted aquifers. ?? 2008 American Chemical Society.

  10. Genes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soils

    Directory of Open Access Journals (Sweden)

    Wang Gejiao

    2009-01-01

    Full Text Available Abstract Background Arsenic is known as a toxic metalloid, which primarily exists in inorganic form [As(III and As(V] and can be transformed by microbial redox processes in the natural environment. As(III is much more toxic and mobile than As(V, hence microbial arsenic redox transformation has a major impact on arsenic toxicity and mobility which can greatly influence the human health. Our main purpose was to investigate the distribution and diversity of microbial arsenite-resistant species in three different arsenic-contaminated soils, and further study the As(III resistance levels and related functional genes of these species. Results A total of 58 arsenite-resistant bacteria were identified from soils with three different arsenic-contaminated levels. Highly arsenite-resistant bacteria (MIC > 20 mM were only isolated from the highly arsenic-contaminated site and belonged to Acinetobacter, Agrobacterium, Arthrobacter, Comamonas, Rhodococcus, Stenotrophomonas and Pseudomonas. Five arsenite-oxidizing bacteria that belonged to Achromobacter, Agrobacterium and Pseudomonas were identified and displayed a higher average arsenite resistance level than the non-arsenite oxidizers. 5 aoxB genes encoding arsenite oxidase and 51 arsenite transporter genes [18 arsB, 12 ACR3(1 and 21 ACR3(2] were successfully amplified from these strains using PCR with degenerate primers. The aoxB genes were specific for the arsenite-oxidizing bacteria. Strains containing both an arsenite oxidase gene (aoxB and an arsenite transporter gene (ACR3 or arsB displayed a higher average arsenite resistance level than those possessing an arsenite transporter gene only. Horizontal transfer of ACR3(2 and arsB appeared to have occurred in strains that were primarily isolated from the highly arsenic-contaminated soil. Conclusion Soils with long-term arsenic contamination may result in the evolution of highly diverse arsenite-resistant bacteria and such diversity was probably caused in

  11. Toward a Mechanistic Source Term in Advanced Reactors: Characterization of Radionuclide Transport and Retention in a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Brunett, Acacia J.; Bucknor, Matthew; Grabaskas, David

    2016-04-17

    A vital component of the U.S. reactor licensing process is an integrated safety analysis in which a source term representing the release of radionuclides during normal operation and accident sequences is analyzed. Historically, source term analyses have utilized bounding, deterministic assumptions regarding radionuclide release. However, advancements in technical capabilities and the knowledge state have enabled the development of more realistic and best-estimate retention and release models such that a mechanistic source term assessment can be expected to be a required component of future licensing of advanced reactors. Recently, as part of a Regulatory Technology Development Plan effort for sodium cooled fast reactors (SFRs), Argonne National Laboratory has investigated the current state of knowledge of potential source terms in an SFR via an extensive review of previous domestic experiments, accidents, and operation. As part of this work, the significant sources and transport processes of radionuclides in an SFR have been identified and characterized. This effort examines all stages of release and source term evolution, beginning with release from the fuel pin and ending with retention in containment. Radionuclide sources considered in this effort include releases originating both in-vessel (e.g. in-core fuel, primary sodium, cover gas cleanup system, etc.) and ex-vessel (e.g. spent fuel storage, handling, and movement). Releases resulting from a primary sodium fire are also considered as a potential source. For each release group, dominant transport phenomena are identified and qualitatively discussed. The key product of this effort was the development of concise, inclusive diagrams that illustrate the release and retention mechanisms at a high level, where unique schematics have been developed for in-vessel, ex-vessel and sodium fire releases. This review effort has also found that despite the substantial range of phenomena affecting radionuclide release, the

  12. Bioremediation of Arsenic: Prospects and Limitations in the Agriculture of Bangladesh

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    MOHAMMAD ZABED HOSSAIN

    2012-06-01

    Full Text Available Arsenic contamination in the groundwater of Bangladesh has been termed as one of the largest mass poisoning in history. The problem of arsenic toxicity in crop plants that occurs through transfer of arsenic from contaminated soil to plant parts is of great concern because of its potential health hazards. Among the various method, bioremediation of arsenic is the most desirable because of low coast, environmental safety and sustainability. This article focuses on the potential of using various methods for arsenic bioremediation and discusses the advantages and challenges of these methods with special emphasis on the problem of Bangladesh. Although remediation through phytoextraction of arsenic in soil seems promissing, disposing plants used as hyper-accumulator is a concern for the environment. Moreover, further improvement of phytoextraction is needed due to the severity of arsenic contamination in the agricultural soils of Bangladesh. Using soil microbes for bioremediatioin also needs further research in order to enhance our knowledge abut the efficient methods suitable for Bangladesh. Information gathered in this article is likely to enhance our knowledge about the arsenic bioremediation among the stakeholders including the policy makers in countries like Bangladesh where the problem of arsenic contamination in agricultural soil is severe.

  13. Arsenic release by indigenous bacteria Bacillus cereus from aquifer sediments at Datong Basin, northern China

    Institute of Scientific and Technical Information of China (English)

    Zuoming XIE; Yanxin WANG; Mengyu DUAN; Xianjun XIE; Chunli SU

    2011-01-01

    Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus (B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and then, it declined.Supplemented with bacteria only, the concentration could increase on the second day. By contrast, the arsenic concentration in the treatment supplemented with sodium citrate or glucose was kept very low. These results indicate that bacterial activities promoted the release of arsenic in the sediments. Bacterial activities also influenced other geochemical parameters of the aqueous phase, such as pH,Eh, and the concentrations of dissolved Fe, Mn, and Al that are important controls on arsenic release. The removal of Fe, Mn, and Al from sediment samples was observed with the presence of B. cereus. The effects of microbial activities on Fe, Mn, and Al release were nearly the same as those on As mobilization. The pH values of the treatments inoculated with bacteria were lower than those without bacteria, still at alkaline levels. With the decrease of Eh values in treatments inoculated with bacteria, the microcosms became more reducing and are thus favorable for arsenic release.

  14. Arsenic release by indigenous bacteria Bacillus cereus from aquifer sediments at Datong Basin, northern China

    Science.gov (United States)

    Xie, Zuoming; Wang, Yanxin; Duan, Mengyu; Xie, Xianjun; Su, Chunli

    2011-03-01

    Endemic arsenic poisoning due to long-term drinking of high arsenic groundwater has been reported in Datong Basin, northern China. To investigate the effects of microbial activities on arsenic mobilization in contaminated aquifers, Bacillus cereus ( B. cereus) isolated from high arsenic aquifer sediments of the basin was used in our microcosm experiments. The arsenic concentration in the treatment with both bacteria and sodium citrate or glucose had a rapid increase in the first 18 d, and the