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Arsenic-related articles - April 2009

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  • Laurel Schaider
    ... List of Topics: 1. Health Effects and Exposure 2. Distribution & Extent of Affected Areas 3. Geochemistry 4. Water Treatment and Alternative Supplies 5.
    Message 1 of 1 , Apr 19, 2009
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      List of Topics:
      1. Health Effects and Exposure
      2. Distribution & Extent of Affected Areas
      3. Geochemistry
      4. Water Treatment and Alternative Supplies
      5. Agriculture and Food Products
      6. Policy Approaches
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      1. HEALTH EFFECTS AND EXPOSURE
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      http://dx.doi.org/10.1080/10934520902719886
      Occurrence of arsenicosis in a rural village of Cambodia,
      2009, DNG Mazumder, KK Majumdar, SC Santra, H Kol, C Vicheth, J. Environ. Sci.
      Health Part A – Toxic/Hazard. Subst. Environ. Eng. 44(5), 480-487.
      Abstract:
      Ninety-seven subjects belonging to 40 families in a village
      in Cambodia were examined in a health camp where all the cases with skin
      disease assembled. These people had evidences of chronic arsenic exposure from
      reports of testing of water samples and of hair and/or nail studied. Seventy
      cases were diagnosed to be suffering from arsenicosis (Clinically and
      laboratory confirmed according to WHO criteria) as all these cases had
      evidences of pigmentation and/or keratosis characteristic of arsenicosis and
      history of exposure of arsenic contaminated water and/or elevated level of
      arsenic in hair and/or in nail. Highest number of cases belonged to age group
      of 31 to 45 yrs, both the sexes are more or less affected equally. Evidence of
      both pigmentation and keratosis were found in 60 cases (85.7%) while only
      pigmentation and only keratosis was found in 6 (8.5%) and 4 (5.7%) cases respectively.
      It was interesting to find 37.04% of children below the age of 16 years had
      skin lesions of arsenicosis. The youngest child having definite evidence of
      keratosis and pigmentation was aged 8 years, though two children aged 4 and 5
      yrs had feature of redness and mild thickening of the palms. The minimum and
      maximum arsenic values detected in the nails were 1.06 and 69.48 mg/Kg
      respectively and the minimum and maximum arsenic values in hair were 0.92 and
      25.6 mg/Kg respectively. No correlation was observed between arsenic
      concentration in drinking water and arsenic level in nail and hair. This is the
      first report of clinical and laboratory confirmed cases of arsenicosis in
      Cambodia.
      -------------------------------------
      http://dx.doi.org/10.2166/wst.2009.844
      Effect of rice-cooking water to the daily arsenic intake
      in Bangladesh: results of field surveys and rice-cooking experiments, 2009,
      K Ohno, Y Matsuo, T Kimura, T Yanase, MH Rahman, Y Magara, T Matsushita, Y
      Matsui, Wat. Sci. Technol., 59(2), 195-201.
      Abstract:
      The effect of rice-cooking water to the daily arsenic intake
      of Bangladeshi people was investigated. At the first field survey, uncooked
      rice and cooked rice of 29 families were collected. Their arsenic
      concentrations were 0.22 +/- 0.11 and 0.26 +/- 0.15 mg/kg dry wt, respectively.
      In 15 families, arsenic concentration in rice increased after cooking. Good
      correlation (R-2 = 0.89) was observed between arsenic in rice-cooking water and
      the difference of arsenic concentration in rice by cooking. In the second
      survey, we collected one-day duplicated food of 18 families. As a result, we
      estimated that six of 18 families likely used the arsenic contaminated water
      for cooking rice even they drank less arsenic-contaminated water for drinking purpose.
      We also conducted rice-cooking experiments in the laboratory, changing arsenic
      concentration in rice-cooking water. Clear linear relationships were obtained
      between the arsenic in rice-cooking water and the difference of arsenic
      concentration in rice by cooking. Factors that affect arsenic concentration in
      cooked rice are suggested as follows: (1) arsenic concentration in uncooked
      rice, (2) that in rice-cooking water, (3) difference in water content of rice
      before and after cooking, and (4) types of rice, especially, the difference
      between parboiled and non-parboiled rice.
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      http://www.ijdvl.com/article.asp?issn=0378-6323;year=2008;volume=74;issue=6;spage=571;epage=581;aulast=Das;type=0
      Arsenicosis: Diagnosis and treatment, 2008, NK Das,
      SR Sengupta, Ind. J. Dermatol. Venereol. Leprolog., 74(6), 571-581.
      Abstract:
      Diagnosis of arsenicosis relies on both clinical and
      laboratory criteria, but principally it can be diagnosed on the basis of its
      cutaneous manifestations. Cutaneous manifestations (melanosis, keratosis, and
      cutaneous cancers) are essential clues in the diagnosis, and trained
      dermatologists or arsenic experts are able to clinically confirm a case even
      without laboratory backup. Although systemic manifestations are not considered
      as diagnostic hallmarks, yet their presence serves as important telltale signs
      in arriving at the diagnosis. In countries where laboratory facilities are
      available, measuring the level of arsenic in drinking water (consumed in the last
      6 months), urine, hair, and nails is of immense value. Newer biomarkers of
      arsenic exposure are being explored to provide early information about arsenic
      intoxication, of which urinary porphyrin level, blood metallothionein have
      shown promising results. Controlling the problem of arsenicosis depends on
      various factors, of which the most important is cessation of intake of
      arsenic-contaminated water. Deep wells, traditional dug wells, treatment of
      surface water, rainwater harvesting, and removing arsenic from the contaminated
      water by arsenic removal plant or arsenic treatment unit are the available
      options for providing arsenic-free drinking water. The role of nutrition and
      antioxidants in preventing the onset of symptoms of arsenicosis is also of
      importance. Nonspecific therapies (e.g., keratolytics for hyperkeratosis)
      cannot also be ignored and serve as palliative measures. The persons affected
      need to be followed up at regular intervals to detect the onset of cancers (if
      any) at the earliest. Role of counseling and education should never be
      underestimated since absence of public awareness can undermine all efforts of
      mitigation measures.
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      http://dx.doi.org/10.1016/j.scitotenv.2008.10.013
      The correlation of arsenic levels in drinking water with
      the biological samples of skin disorders, 2009, TG Kazi, MB Arain, JA Baig,
      MK Jamali, HI Afridi, N Jalbani, RA Sarfraz, AQ Shah, A Niaz, Sci. Tot. Env.,
      407(3), 1019-1026.
      Abstract:
      Arsenic (As) poisoning has become a worldwide public health
      concern. The skin is quite sensitive to As and skin lesions are the most common
      and earliest nonmalignant effects associated to chronic As exposure. In
      2005-2007, a survey was carried out on surface and groundwater arsenic
      contamination and relationships between As exposure via the drinking water and
      related adverse health effects (melanosis and keratosis) on villagers southern
      part of Sindh resides on the banks of Manchar lake Pakistan We screened the,,.
      population from arsenic-affected villages, 61 to 73% population were identified
      patients suffering from chronic arsenic toxicity. The effects of As toxicity
      via drinking water were estimated by biological samples (scalp hair and blood)
      of adults (males and females), have or have not skin problem (n = 187). The
      referent samples of both genders were also collected from the areas having low
      level of As (<10 mu g/L) in drinking water (n = 121). Arsenic concentration
      in drinking water and biological samples were analyzed using electrothermal atomic
      absorption spectrometry. The range of arsenic concentrations in lake surface
      water was 35.2-158 mu g/L, which is 3-15 folds higher than. World Health
      Organization [WHO, 2004. Guidelines for drinking-water quality third ed., WHO
      Geneva Switzerland.]. It was observed that As concentration in the scalp hair
      and blood samples were above the range of permissible values 0.034-0.319 mu g
      As/g for hair and <0.5-4.2 mu g/L for blood. The linear regressions showed
      good correlations between arsenic concentrations in water versus hair and blood
      samples of exposed skin diseased subjects (R-2 = 0.852 and 0.718) as compared
      to non-diseased subjects (R-2 = 0.573 and 0.351), respectively.
      -------------------------------------
      http://dx.doi.org/10.2478/10004-1254-59-2008-1871
      Arsenic exposure through drinking water and its effect on
      pregnancy outcome in Bengali women, 2008, J Sen, ABD Chaudhuri, Arch. Ind.
      Hyg. Toxicol., 59(4), 271-275.
      Abstract:
      Twelve districts of the state of West Bengal, India are
      affected by arsenic (As) and millions of individuals are consuming
      As-contaminated groundwater. The probable adverse effects of As on pregnancy
      outcome (stillbirth and miscarriage) are yet to be properly studied, The
      present investigation is an attempt to understand the effects of As exposure on
      the pregnancy outcome in Bengali women exposed to As through drinking water and
      residing in different villages in North 24 Parganas District of West Bengal.
      The results show a significantly higher rate of stillbirths and miscarriages than
      those in the unexposed population.
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      http://dx.doi.org/10.1016/j.apgeochem.2008.06.009
      A comparison of two techniques for calculating
      groundwater arsenic-related lung, bladder and liver cancer disease burden using
      data from Chakdha block, West Bengal, 2008, D Mondal, GCD Adamson, R
      Nickson, DA Polya, Appl. Geochem., 23(11), 2999-3009.
      Abstract:
      Calculation of excess disease burden for As exposed
      populations is becoming increasingly important to enable quantitative estimation
      of the impacts of various As mitigation options. There are several methods by
      which such calculations may be carried out. In this study, two methods,
      recently applied to estimating groundwater As-related health risks in southern
      Asia, to estimate disease burden arising from lung, bladder and liver cancer
      from As exposure for an As-effected area of West Bengal have been compared.
      Both utilized calculated distributions of exposure of the studied population to
      As from groundwater. Method (I) then entailed calculating disease burden by
      combining published background rates for death and disability adjusted life
      years (DALYs) and standard mortality ratios (SMRs) for excess health impacts
      related to As exposure, whilst for Method (II). disease burden from As exposure
      was estimated using the basic DALY formula, combined with incidence rates based
      on the NRC multistage Weibull model. Dose-response data for both methods were
      based on Studies in Taiwan.
      When the
      same dose-response model was used for both methods, the two methods were
      broadly comparable, agreeing to within a factor of 4 for both deaths and DALYs.
      Much larger differences, up to a factor of 40, were noted when SMRs from
      different previous studies were utilized by Method (1). Thus, the death and DALYs
      calculations are most sensitive to the choice of dose-response model and less
      so to the calculation method. The differences are also partly ascribed to
      different background (i.e. for As non-exposed populations) rates for lung,
      bladder and liver cancers between Chakdha block and Taiwan. However, the
      differences also highlight some of systematic uncertainties in the application
      of epidemiological studies in one part of the world to another, emphasizing
      that accurate health risk estimates are likely to be better obtained by large
      scale systematic surveys of health outcomes in the study population.
      Irrespective of the comparability of the results of the two methods, it is
      noted that the lack of detailed consideration of confounding factors such as
      genetic polymorphisms, smoking and dietary habits, and, in particular, exposure
      to As through other routes, notably ingestion of As-bearing rice, may
      significantly impact on the accuracy of the results obtained by either method.
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      2. DISTRIBUTION & EXTENT OF AFFECTED AREAS
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      http://dx.doi.org/10.1289/ehp.11886
      Public health strategies for Western Bangladesh that
      address arsenic, manganese, uranium, and other toxic elements in drinking water,
      2009, SH Frisbie, EJ Mitchell, LJ Mastera, DM Maynard, AZ Yusuf, MY Siddiq, R
      Ortega, RK Dunn, DS Westerman, T Bacquart, B Sarkar, Environ. Health Perspect.,
      117(3), 410-416.
      Abstract:
      BACKGROUND: More than 60,000,000 Bangladeshis are drinking
      water with unsafe concentrations of one or more elements.
      OBJECTIVES: Our aims in this study were to evaluate and
      improve the drinking water testing and treatment plans for western Bangladesh.
      METHODS: We sampled groundwater from four neighborhoods in
      western Bangladesh to determine the distributions of arsenic, boron, barium,
      chromium, iron, manganese, molybdenum, nickel, lead, antimony, selenium,
      uranium, and zinc, and to determine pH.
      RESULTS: The percentages of tube wells that had
      concentrations exceeding World Health Organization (WHO) health-based drinking
      water guidelines were 78% for Mn, 48% for U, 33% for As, 1% for Pb, 1% for Ni,
      and 1% for Cr. Individual tube wells often had unsafe concentrations of both Mn
      and As or both Mn and U. They seldom had unsafe concentrations of both As and
      U.
      CONCLUSIONS: These results suggest that the ongoing program
      of identifying safe drinking water supplies by testing every tube well for As
      only will not ensure safe concentrations of Mn, U, Pb, Ni, Cr, and possibly
      other elements. To maximize efficiency, drinking water testing in Bangladesh
      should be completed in three steps: 1) all tube wells must be sampled and
      tested for As; 2) if a sample meets the WHO guideline for As, then it should be
      retested for Mn and U; 3) if a sample meets the WHO guidelines for As, Mn, and
      U, then it should be retested for B, Ba, Cr, Mo, Ni, and Ph. All safe tube
      wells should be considered for use as public drinking water supplies.
      -------------------------------------
      http://dx.doi.org/10.1016/j.envint.2008.06.003
      Arsenic contamination of groundwater in the Terai region
      of Nepal: An overview of health concerns and treatment options, 2009, D
      Pokhrel,BS Bhandari,T Viraraghavan, Environ. Internat., 35(1), 157-161.
      Abstract:
      A review of published information on the arsenic
      contamination of groundwater in the Terai regions of Nepal showed that the
      source was mainly geogenic due to the dissolution of the arsenic-bearing
      minerals. Clinical observations of patients in the arsenic affected districts
      revealed chronic arsenic poisoning from drinking water. Half a million people
      inhabiting the region are believed to have been exposed to arsenic levels
      greater than 50 mu g/L in their drinking water. Thirty-one percent of the
      population (3.5 million) in the region are estimated to have been exposed to
      arsenic levels between 10 and 50 mu g/L Iron assisted biosand filters currently
      distributed and in operation are a suitable alternative to mitigate the interim
      arsenic standard of 50 mu g/L, as set by the Nepal Government. Arsenic biosand
      filters were also effective in removing bacteria and viruses from drinking
      water in laboratory and field tests. However, groundwater treatment targeting
      cluster communities in the Terai region is the sustainable way of mitigating
      the arsenic problem.
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      3. GEOCHEMISTRY
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      http://dx.doi.org/10.1007/s00254-008-1319-8
      Geochemistry and mineralogy of shallow alluvial aquifers
      in Daudkandi upazila in the Meghna flood plain, Bangladesh, 2009, MA Hasan,
      M von Broemssen, P Bhattacharya, KM Ahmed, AM Sikder, G Jacks, O Sracek,
      Environ. Geol., 57(3), 499-511.
      Abstract:
      The shallow alluvial aquifers of the delta plains and flood
      plains of Bangladesh, comprises about 70% of total land area are mostly
      affected by elevated concentrations of arsenic (As) in groundwater exposing a
      population of more than 35 million to As toxicity. Geochemical studies of
      shallow alluvial aquifer in the Meghna flood plain show that the uppermost
      yellowish grey sediment is low in As (1.03 mg/kg) compared to the lower dark
      grey to black sediment (5.24 mg/kg) rich in mica and organic matter. Sequential
      extraction data show that solid phase As bound to poorly crystalline and
      amorphous metal (Fe, Mn, Al)-oxyhydroxides is dominant in the grey to dark grey
      sediment and reaches its maximum level (3.05 mg/kg) in the mica rich layers. Amount
      of As bound to sulphides and organic matter also peaks in the dark grey to
      black sediment. Vertical distributions of major elements determined by X-ray
      fluorescence (XRF) show that iron (Fe2O3), aluminum (Al2O3) and manganese (MnO)
      follow the general trend of distribution of As in the sediments. Concentrations
      of As, Mn, Fe, HCO3 (-), SO4 (2-) and NO3 (-) in groundwater reflect the redox
      status of the aquifer and are consistent with solid phase geochemistry.
      Mineralogical analysis by X-ray diffraction (XRD) and scanning electron
      microscopy (SEM) fitted with energy dispersive X-ray spectrometer (EDS)
      revealed dominance of crystalline iron oxides and hydroxides like magnetite,
      hematite and goethite in the oxidised yellowish grey sediment. Amorphous Fe-oxyhydroxides
      identified as grain coating in the mica and organic matter rich sediment
      suggests weathering of biotite is playing a critical role as the source of
      Fe(III)-oxyhydroxides which in turn act as sink for As. Presence of authigenic
      pyrite in the dark grey sediment indicates active reduction in the aquifer.
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      http://dx.doi.org/ 10.1007/s00254-008-1267-3
      Near surface lithology and spatial variation of arsenic
      in the shallow groundwater: southeastern Bangladesh, 2009, MA Hoque, AA
      Khan, M Shamsudduha, MS Hossain, T Islam, SH Chowdhury, Environ. Geol., 56(8),
      1687-1695.
      Abstract:
      This study investigated the relationship between
      near-surface lithology and the spatial variability of As concentrations using
      sediment grain-size analysis and electromagnetic induction survey in the
      southeast Bangladesh. It has been observed that the aquifers overlain by finer
      sediments have higher concentrations of As in groundwater, whereas As
      concentrations are remarkably low in aquifers having permeable sandy materials
      or thinner silt/clay layer at the surface. The near-surface lithology acts as a
      controlling factor for spatial distributions of groundwater As within the very
      shallow depths (< 15 m). Shallow alluvial aquifers can provide low-As
      drinking water in many areas of the country when tube wells are properly
      installed after investigation of the overlying near-surface sediment attributes
      and hydraulic properties.
      -------------------------------------
      http://dx.doi.org/10.1007/s00254-008-1221-4
      Study of subsurface geology in locating arsenic-free
      groundwater in Bengal delta, West Bengal, India, 2009, T Pal, PK Mukherjee,
      Environ. Geol., 56(6), 1211-1225.
      Abstract:
      Over a large area of the Bengal delta in West Bengal, India,
      arsenic distribution patterns in groundwater were studied. One hundred and ten
      boreholes at different target locations were made, subsurface sediments were
      logged and analysed, and arsenic values in sediments vis-a-vis groundwater were
      compared. The study elucidates the subsurface geology of the western part of
      Bengal delta and characterises the sediments that were intersected in different
      boreholes with contrasting values of arsenic in groundwater. It reveals an
      existence of multiple aquifers stacked over each other. Depending on the color
      and nature of aquifer-sands and their overlying clay beds six aquifer types
      (Type-1 to Type-6) are classified and described. Sediment-arsenic for all the
      varieties of aquifer sands are near similar but the groundwater-arsenic of
      these six aquifers varies widely. Type-2 and Type-5 aquifers host
      arsenic-contaminated groundwater whereas the other four aquifers are
      arsenic-free. Type-2 and Type-5 aquifers are capped by a grey to dark grey soft
      organic matter-rich clay unit which makes these aquifers semi-confined to
      leaky-confined. These contribute in releasing arsenic from the sediments. The
      results of this study are employed in a proposed georemedial measure against
      this hazardous toxic element.
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      http://dx.doi.org/10.1016/j.apgeochem.2008.06.017
      Hydrological and geochemical constraints on the mechanism
      of formation of arsenic contaminated groundwater in Sonargaon, Bangladesh,
      2008, T Itai, H Masuda, AA Seddique, M Mitamura, T Maruoka, XD Li, M Kusakabe,
      BK Dipak, A Farooqi, T Yamanaka, S Nakaya, J Matsuda, KM Ahmed, Appl. Geochem.,
      23(11), 3155-3176.
      Abstract:
      The geochemical characteristics and hydrological constraints
      of high As groundwater in Sonargaon, in mid-eastern Bangladesh were
      investigated in order to ascertain the mechanism of As release into the
      groundwaters from host sediments in the Ganges-Brahma putra delta. Samples of
      groundwater were collected from ca. 230 tube wells in both the rainy and dry
      seasons. Similar to previous studies, high As groundwater was found in the
      Holocene unconfined aquifer but not in the Pleistocene aquifer. Groundwaters in
      the Holocene aquifer were of the Ca-Mg-HCO3 type with major solutes derived
      from chemical weathering of detrital minerals such as plagioclase and biotite.
      Groundwater with high As was generally characterized by high NH4+, possibly
      derived from the agricultural application of fertilizer as suggested by the
      small variation of delta N-15(NH4) (mostly 2-4 parts per thousand).
      Concentrations of Fe changed between the rainy and dry seasons by
      precipitation/dissolution of Fe oxyhydroxide and siderite, whilst there was not
      an apparent concomitant change in As. Inhomogeneous spatial distribution of
      delta O-18 in the Holocene unconfined aquifer indicates poor mixing of
      groundwater in the horizontal direction. Spatial variation of redox conditions
      is associated with localized variations in subsurface permeability and the
      recharge/discharge cycle of groundwater. Hydrogeochemical data presented in
      this paper suggest that reduction of Fe oxyhydroxide is not the only mechanism
      of As mobilization, and chemical weathering of biotite and/or other basic
      minerals in the Holocene aquifer could also be important as a primary cause of
      As mobilization.
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      4. WATER TREATMENT AND ALTERNATIVE SUPPLIES
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      http://dx.doi.org/10.1021/es802394p
      Treatment of arsenic, heavy metals, and acidity using a mixed
      ZVI-compost PRB, 2009, RD Ludwig, DJA Smyth, DW Blowes, LE Spink, RT Wilkin,
      DG Jewett, CJ Weisener, Environ. Sci. Technol., 43(6), 1970-1976.
      Abstract:
      A 30-month performance evaluation of a pilot permeable
      reactive barrier (PRB) consisting of a mixture of leaf compost zero-valent iron
      (ZVI), limestone, and pea gravel was conducted at a former phosphate fertilizer
      manufacturing facility in Charleston, SC. The PRB is designed to remove heavy
      metals and arsenic from groundwater by promoting microbially mediated sulfate
      reduction and sulfide-mineral precipitation and arsenic and heavy metal
      sorption. Performance monitoring showed effective treatment of As, Pb, Cd, Zn,
      and Ni from concentrations. as high as 206 mg L-1, 2.02 mg L-1, 0.324 mg L-1,
      1060 mg L-1, and 2.12 mg L-1, respectively, entering the PRB, to average
      concentrations of <0.03 mg L-1, < 0.003 mg L-1, < 0.001 mg L-1, <
      0.23 mg L-1, and <0.003 mg L-1, respectively, within the PRB. Both As(III))
      and As(V) were effectively removed from solution with X-ray absorption near
      edge structure (XANES) analysis of core samples indicating the presence of
      As(V) in oxygen-bound form and As(III) in both oxygen- and sulfur-bound forms.
      XANES solid phase sulfur analysis indicated decreases in the peak amplitude of
      intermediate oxidized sulfur species and sulfate components with increasing
      distance and depth within the PRB.
      -------------------------------------
      http://dx.doi.org/10.1080/09603120802272219
      Flocculant-disinfectant point-of-use water treatment for
      reducing arsenic exposure in rural Bangladesh, 2009, DM Norton, M Rahman, AL
      Shane, Z Hossain, RM Kulick, MI Bhuiyan, MA Wahed, M Yunus, MS Islam, RF Breiman,
      A Henderson, BH Keswick, SP Luby, Int. J. Environ. Health Res., 19(1), 17-29.
      Abstract:
      We introduced flocculant-disinfectant water treatment for 12
      weeks in 103 households in Bangladesh to assess if drinking water would be
      chemically and microbiologically improved and the body burden of arsenic
      reduced. The median concentration of arsenic in tubewell water decreased by 88%
      after introduction of the flocculant-disinfectant from 136g/l at baseline to 16
      (p0.001). The median concentration of total urinary arsenic decreased 42% from
      385g/g creatinine at baseline to 225g/g creatinine after intervention (p0.001).
      Among 206 post-intervention drinking water samples that were reportedly treated
      on the date the sample was collected, 99 (48%) lacked residual free chlorine
      and 100 (49%) were contaminated with thermotolerant coliforms. The
      flocculant-disinfectant markedly reduced arsenic in drinking water, but treated
      drinking water was frequently contaminated with fecal organisms. The lesser
      reduction in urinary arsenic compared to water arsenic and the health
      consequences of this reduction require further research.
      -------------------------------------
      http://dx.doi.org/10.2166/wst.2008.751
      A contribution to solve the arsenic problem in
      groundwater of Ganges Delta by in-situ treatment, 2008, U Rott, H Kauffman,
      Wat. Sci. Technol., 58(10), 2009-2015.
      Abstract:
      Arsenic in groundwater is a huge problem in numerous regions
      of the world. Many people are exposed to high arsenic concentrations and
      consequently risk getting ill or even die as a result of arsenic poisoning.
      There are several efficient technologies for the removal of arsenic but often
      these methods have disadvantages, e. g. high costs for installation and/or
      operation, the need for chemicals or the production of arsenic contaminated
      filter sludge. These disadvantages can make the application difficult,
      especially in poor regions. Under suitable ancillary conditions the
      subterranean (in-situ) treatment, which is often used for iron and manganese
      removal from groundwater, can also be applied for the removal of arsenic and
      can be a cost-effective treatment technology. A field trial was carried out
      with a low-cost in-situ treatment plant in West Bengal/India which is described
      in this paper, in order to investigate whether this treatment technology is
      also applicable under the boundary conditions there. As for the in-situ
      treatment technology besides oxygen no additives are required and no arsenic
      contaminated filter sludge is produced this technology could be a suitable
      method for arsenic removal especially in poor regions.
      -------------------------------------
      http://dx.doi.org/10.1016/j.envpol.2008.05.022
      In field arsenic removal from natural water by
      zero-valent iron assisted by solar radiation, 2008, L Cornejo, H Lienqueo,
      M Arenas, J Acarapi, D Contreras, J Yanez, HD Mansilla, Environ. Poll., 156(3),
      827-831.
      Abstract:
      An in situ arsenic removal method applicable to highly
      contaminated water is presented. The method is based in the use of steel wool,
      lemon juice and solar radiation. The method was evaluated using water from the Camarones
      River, Atacama Desert in northern Chile, in which the arsenic concentration
      ranges between 1000 and 1300 mu g L-1. Response surface method analysis was
      used to optimize the amount of zero-valent iron (steel wool) and the citrate
      concentration (lemon juice) to be used. The optimal conditions when using solar
      radiation to remove arsenic from natural water from the Camarones river are:
      1.3 g L-1 of steel wool and one drop (ca. 0.04 mL) of lemon juice. Under these
      conditions, removal percentages are higher than 99.5% and the final arsenic
      concentration is below 10 mu g L-1. This highly effective arsenic removal
      method is easy to use and inexpensive to implement.
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      5. AGRICULTURE AND FOOD PRODUCTS
      --------------------------------------------------------------------
      http://dx.doi.org/10.1007/s11104-008-9786-y
      Arsenic toxicity to rice (Oryza sativa L.) in Bangladesh,
      2009, GM Panaullah, T Alam, MB Hossain, RH Loeppert, JG Lauren, CA Meisner, ZU
      Ahmed JM Duxbury, Plant Soil, 317(1-2), 31-39.
      Abstract:
      Natural contamination of groundwater with arsenic (As)
      occurs around the world but is most widespread in the river basin deltas of
      South and Southeast Asia. Shallow groundwater is extensively used in the Bengal
      basin for irrigation of rice in the dry winter season, leading to the
      possibility of As accumulation in soils, toxicity to rice and increased levels
      of As in rice grain and straw. The impact of As contaminated irrigation water
      on soil-As content and rice productivity was studied over two winter-season
      rice crops in the command area of a single tubewell in Faridpur district,
      Bangladesh. After 16-17 years of use of the tubewell, a spatially variable
      build up of As and other chemical constituents of the water (Fe, Mn and P) was
      observed over the command area, with soil-As levels ranging from about 10 to 70
      mg kg(-1). A simple mass balance calculation using the current water As level
      of 0.13 mg As L-1 suggested that 96% of the added arsenic was retained in the
      soil. When BRRI dhan 29 rice was grown in two successive years across this
      soil-As gradient, yield declined progressively from 7-9 to 2-3 t ha(-1) with
      increasing soil-As concentration. The average yield loss over the 8 ha command
      area was estimated to be 16%. Rice-straw As content increased with increasing
      soil-As concentration; however, the toxicity of As to rice resulted in reduced
      grain-As concentrations in one of the 2 years. The likelihood of As-induced
      yield reductions and As accumulation in straw and grain has implications to
      agricultural sustainability, food quality and food security in As-affected
      regions throughout South and Southeast Asia.
      -------------------------------------
      http://dx.doi.org/10.1007/s11104-008-9798-7
      The effects of iron plaque and phosphorus on yield and
      arsenic accumulation in rice, 2009, MB Hossain, M Jahiruddin, RH Loeppert, GM
      Panaullah, MR Islam, JM Duxbury, Plant Soil, 317(1-2), 167-176.
      Abstract:
      The effects of arsenate, Fe2+, and phosphate on amount and
      composition of Fe-oxide plaque at the rice-root surface and on the yield and
      arsenic accumulation in rice (cv. BRRI dhan33) were studied in a replicated
      pot-culture experiment. Arsenic in the form of Na2HAsO4 was applied at
      concentrations of 0, 15 and 30 mg kg(-1) in combination with P and/or Fe at 0
      and 50 mg kg(-1), from KH2PO4 and FeSO4, respectively. Root, grain and straw
      yields and their As, Fe and P concentrations were determined. The Fe-oxide
      plaque was extracted from the plant roots using dithionite-citrate-bicarbonate
      (DCB) and NH4-oxalate extractions. The addition of Fe2+ reduced the toxic
      effect of As in flooded-rice culture and resulted in reduced grain-As
      accumulation and increased grain yields. The effect of applied phosphate was
      the opposite, in that it resulted in higher As concentrations in both grain and
      straw and lower grain yields. The effects of both Fe and P can be explained
      based on their impacts on adsorption of As onto soil and rice-plaque Fe-oxides
      and the subsequent As solubility and availability for uptake by rice. These
      reactions have important implications to rice-crop management and the natural
      variability in soils and irrigation-water characteristics that might impact As
      uptake by rice.

      -------------------------------------
      http://dx.doi.org/10.1021/es802794w
      Baseline soil variation is a major factor in arsenic accumulation
      in Bengal Delta paddy rice, 2009, Y Lu, EE Adomakok ARM Solaiman, MR Islam,
      C Deacon, PN Williams, GKMM Rahman, AA Meharg, Environ. Sci. Technol., 43(6),
      1724-1729.
      Abstract:
      Factors responsible for paddy soil arsenic accumulation in
      the tubewell irrigated systems of the Bengal Delta were investigated. Baseline
      (i.e., nonirrigated) and paddy soils were collected from 30 field systems
      across Bangladesh. For each field, soil sampled at dry season (Boro) harvest
      i.e., the crop cycle irrigated with tubewell water, was collected along a 90 m
      transect away from the tubewell irrigation source. Baseline soil arsenic levels
      ranged from 0.8 to 21. mg/kg, with lower values found on the Pliestocene
      Terrace around Gazipur (average, 1.6 +/- 0.2 mg/kg), and higher levels found in
      Holecene sediment tracts of Jessore and Faridpur (average, 6.6 +/- 1.0 mg/kg).
      Two independent approaches were used to assess the extent of arsenic build-up
      in irrigated paddy soils. First, arsenic build-up in paddy soil at the end of
      dry season production (irrigated - baseline soil arsenic) was regressed against
      number of years irrigated and tubewell arsenic concentration. Years of irrigation
      was not significant (P 0.711), indicating no year-on-year arsenic build-up,
      whereas tubewell As concentration was significant (P = 0.008). The second
      approach was analysis of irrigated soils for 20 fields over 2 successive years.
      For nine of the fields there was a significant (P < 0.05) decrease in soil
      arsenic from year 1 to 2, one field had a significant increase, whereas there
      was no change for the remaining 10. Over the dry season irrigation cycle, soil
      arsenic built-up in soils at a rate dependent on irrigation tubewell water, 35*
      (tubewell water concentration in mg/kg, mg/L). Grain arsenic rises steeply at
      low soil/shoot arsenic levels, plateauing out at concentratations. Baseline
      soil arsenic at Faridpur sites corresponded to grain arsenic levels at the
      start of this saturation phase. Therefore, variation in baseline levels of soil
      arsenic leads to a large range in grain arsenic. Where sites have high baseline
      soil arsenic, further additional arsenic from irrigation water only leads to a
      gradual increase in grain arsenic concentration.
      -------------------------------------
      http://dx.doi.org/10.1007/s00128-008-9502-x
      Distribution of arsenic and trace metals in the floodplain agricultural soil of Bangladesh, 2009, DA Ahsan, TA DelValls, J
      Blasco, Bull. Environ. Contam. Toxicol., 82(1), 11-15.
      Abstract:
      Arsenic contaminated groundwater of Bangladesh is one of the
      largest natural calamities of the world. Soil samples were collected from
      floodplain agricultural land of Faridpur and Dhamrai regions to estimate the
      concentration of arsenic and other trace metals (copper, nickel, zinc,
      chromium, cadmium, lead, selenium, cobalt, mercury, and manganese). Average
      arsenic in Faridpur soil was recorded more than three times higher than the
      world limit and nearly five times higher than that of Dhamrai. The average
      copper, chromium and cobalt both in Faridpur and Dhamrai agricultural soil were
      also higher than the Dutch and the world standards. Both Fardipur and Dhamrai
      soil contain low amount of selenium in comparison to world limit (0.7 mg
      kg(-1)). A poor correlation between manganese and arsenic was noticed in
      Faridpur. This may be played a subordinate role in the fixation of arsenic in
      soil. This study also reveals that the area which has arsenic and trace metal
      contaminated groundwater may also contain high level of arsenic and trace
      metals in the agricultural soil due to irrigation with contaminated
      groundwater.
      -------------------------------------
      http://dx.doi.org/10.1016/j.apgeochem.2008.06.025
      Rice is a major exposure route for arsenic in Chakdaha
      block, Nadia district, West Bengal, India: A probabilistic risk assessment,
      2008, D Mondal, DA Polya, Appl. Geochem., 23(11), 2987-2998.
      Abstract:
      The importance or otherwise of rice as an exposure pathway
      for As ingestion by people living in Bengal and other areas impacted by
      hazardous As-bearing groundwaters is currently a matter of some debate. Here
      this issue is addressed by determining the overall increased cancer risk due to
      ingestion of rice in an As-impacted district of West Bengal. Human target
      cancer health risks have been estimated through the intake of As-bearing rice
      by using combined field, laboratory and computational methods. Monte Carlo
      simulations were run following fitting of model probability curves to measured
      distributions of (i) As concentration in rice and drinking water and (ii)
      inorganic As content of rice and fitting distributions to published data on (i)
      ingestion rates and (ii) body weight and point estimates on bioconcentration
      factors, exposure duration and other input variables. The distribution of As in
      drinking water was found to be substantially lower than that reported by
      previous authors for As in tube wells in the same area. indicating that the use
      of tube well water as a proxy for drinking water is likely to result in human
      health risks being somewhat overestimated. The calculated median increased
      lifetime cancer risk due to cooked rice intake was 7.62 x 10(-4), higher than
      the 10(-4)-10(-6) range typically used by the USEPA as a threshold to guide
      determination of regulatory values and similar to the equivalent risk from
      water intake. The median total risk from combined rice and water intake was
      1.48 x 10(-3). The contributions to this median risk from drinking water, rice
      and cooking of rice were found to be 48%, 44% and 8%, respectively. Thus, rice
      is a major potential source of As exposure in the As-affected study areas in
      West Bengal and the most important exposure pathway for groups exposed to low
      or no As in drinking water.
      -------------------------------------
      http://dx.doi.org/10.1016/j.envpol.2008.02.009
      Groundwater-soil-crop relationship with respect to
      arsenic contamination in farming villages of Bangladesh - A preliminary study,
      2008, K Kurosawa, K Egashira, M Tani, M Jahiruddin, AZM Moslehuddin, ZM Rahman,
      Environ. Poll., 156(2), 563-565.
      Abstract:
      To clarify the groundwater-soil-crop relationship with
      respect to arsenic (As) contamination, As concentration was measured in
      tubewell (TW) water. surface soil from farmyards and paddy fields. and fresh
      taro (Colocasia esculenta) leaves from farmyards in the farming villages of
      Bangladesh. The As concentration in TW water from farmyards was at least four
      times higher than the Bangladesh drinking water standard. and the concentration
      in fresh taro leaves was equal to or higher than those reported Previously for
      leafy vegetables in Bangladesh. As concentration of surface soils in both
      farmyards and paddy fields was positively correlated with that of the TW water.
      Further, the concentration in Surface soil was positively correlated with
      levels in fresh taro leaves in the farmyard. This Study, therefore. clarified
      the groundwater-soil-crop relationship in farmyards and the relationship
      between groundwater-soil in paddy fields to assess the extent of As
      contamination in Bangladeshi villages.
      --------------------------------------------------------------------
      6. POLICY APPROACHES
      --------------------------------------------------------------------
      http://dx.doi.org/10.2166/wp.2009.005
      Arsenic contamination in water resources: mitigation and
      policy options, 2009, I Sekar, T Randhir, Wat. Policy, 11(1), 67-78.
      Abstract:
      Risk of arsenic contamination in water supplies continues to
      increase in many countries, especially in developing nations. Its sources and
      effects are multiple and diffused in nature and it requires detailed assessment
      and policy. This paper discusses the global extent of the problem, its sources
      and effects and explores different policy options. Sources and pathways of
      interaction require comprehensive assessment and policy. Innovation in low cost
      technologies offers possibilities for reducing abatement cost and for economic
      efficiency. To reduce arsenic in water resources, incentive policies such as
      taxing and subsidizing can be used to reduce arsenic levels in point sources
      through creation of appropriate incentives. The paper also identifies
      opportunities for enhancing self-protection efforts through education and
      information sharing. Under a self-protection policy, though the damages decline
      to a greater extent, there is a possibility of an increase in arsenic emission.
      We propose a combination of policies that involve low cost technology,
      education and awareness to mitigate the damage from arsenic contamination at a
      watershed scale. It is also necessary to enforce these policies through
      appropriate institutional changes that involve coordination and cooperative
      efforts to mitigate arsenic contamination.
      -------------------------------------
      http://www.ijdvl.com/article.asp?issn=0378-6323;year=2008;volume=74;issue=6;spage=582;epage=593;aulast=Ghosh
      Epidemiology and prevention of chronic arsenicosis: An
      Indian perspective, 2008, P Ghosh, C Roy, NK Das, SR Sengupta, Ind. J.
      Dermatol. Venereol. Leprolog., 74(6), 582-593.
      Abstract:
      Arsenicosis is a global problem but the recent data reveals
      that Asian countries, India and Bangladesh in particular, are the worst
      sufferers. In India, the state of West Bengal bears the major brunt of the
      problem, with almost 12 districts presently in the grip of this deadly disease.
      Recent reports suggest that other states in the Ganga/Brahmaputra plains are
      also showing alarming levels of arsenic in ground water. In West Bengal, the
      majority of registered cases are from the district of Nadia, and the maximum
      number of deaths due to arsenicosis is from the district of South 24 Paraganas.
      The reason behind the problem in India is thought to be mainly geogenic, though
      there are instances of reported anthropogenic contamination of arsenic from
      industrial sources. The reason for leaching of arsenic in ground water is
      attributed to various factors, including excessive withdrawal of ground water
      for the purpose of irrigation, use of bio-control agents and phosphate
      fertilizers. It remains a mystery why all those who are exposed to
      arsenic-contaminated water do not develop the full-blown disease. Various host
      factors, such as nutritional status, socioeconomic status, and genetic
      polymorphism, are thought to make a person vulnerable to the disease. The
      approach to arsenicosis mitigation needs be holistic, sustainable, and
      multidisciplinary, with the 2 main pillars being health education and provision
      of arsenic-free water. In the state of West Bengal, the drive for arsenic
      mitigation has been divided into 3 phases using various methods, including new
      hand pumps/tube wells at alternative deep aquifers, dug wells, arsenic removal
      plants, arsenic treatment units, as well as piped and surface water supply
      schemes. The methods have their own limitations, so it is intended that a
      pragmatic approach be followed in the arsenicosis prevention drive. It is also
      intended that the preventive measures be operationally and economically
      feasible for the people living in the affected areas.




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