Arsenic:The Geography of a Global problem

A symposiumOn Wednesday 29 August

At the Royal Geographical Society-Institute of British Geographers

Annual Conference

Royal Geographical Society1 Kensington Gore

London

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SESSION 1 - Extent, severity and nature of Arsenic contamination

(1) The largest identified man-made environmental catastrophe

Richard Wilson, D Phil., Harvard Universitywilson5@fas.harvard.edu

The problem of arsenic in South East Asia, particularly Bangladesh is the largest identifiedman made environmental catastrophe. The catastrophe demands three simultaneous actions.(1) Understanding the causes of the catastrophe; (a) why was arsenic present;(b) why was it made available in drinking water?; and(c) why did no one recognize what was happening in time to avert the catastrophe?

(2) What exactly is the effect on humans of arsenic in the amounts present in the drinkingwater?

(3) How can one rapidly bring pure water to the population to avoid further damage?

and a fourth question which is less urgent but crucially important.

(4) How can the world avoid such catastrophes in the future whether from arsenic or fromsome presently unknown cause?

The first three were posed at an International meeting in Dhaka in 1998. I will review theappalling lack of progress in these, especially in item (3) with which I am most familiar.

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(2) Predicting the Global Distribution of Natural Arsenic Contamination ofGroundwater

Peter RavenscroftDepartment of Geography, Cambridge University (pr291@cam.ac.uk)

Over two hundred instances of arsenic contamination of groundwater due to natural causeshave been recognised from 60 countries in five continents. Arsenic is mobilised intogroundwater through four common mechanisms: reductive-dissolution, alkali-desorption,sulphide oxidation, and geothermal action. In terms of impact, by far the most important isreductive dissolution, while alkali-desorption is the second most important. Evaporation mayincrease concentrations of arsenic initially generated by any of these mechanisms. Two maincompensatory processes, adsorption and sulphate reduction, act to remove arsenic fromgroundwater. The mobilisation mechanisms operate in systematic geological–climaticassociations. Two geological associations dominate the occurrence of arsenic. The first iswith alluvial aquifers, and the second is a spatial association with recent mountain building(foreland basins). In alluvial basins, the occurrence of arsenic can be related to weathering,transportation and depositional conditions, which are reflected in the sand mineralogy andchemistry of the rivers. Although local factors may act to prevent arsenic contamination atindividual locations, these associations allow regional and global predictions of whereencountering arsenic-contaminated groundwater is most likely. Classified by mobilisationmechanism and geological–climatic association, the present distribution of arsenic-contamination appears seriously incomplete, with entire continents apparently lackingexamples of some mechanisms. Such predictions have led to the identification of arsenic inalluvial and glacial aquifers on three continents. Regions judged to be at high risk, as opposedthose merely lacking data, are identified. Testing groundwater in these regions should be ahigh priority.

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(3) Arsenic and Manganese Contamination of Drinking Water Resources in Cambodia:Coincidence of Risk Areas with Low Relief Topography

Dr. Johanna Buschmann, Chemist, Eawag johanna.buschmann@eawag.chMr. Michael Berg, Chemist, EawagMrs Caroline Stengel, Lab Technician, EawagMr. Mickey Sampson, Chemist, RDIC

Arsenic contamination of groundwater has been identified in Cambodia, where some 100,000wells are used for drinking water needs. We conducted a comprehensive groundwater surveyin the Mekong Delta, comprising an area of 3700 km2 (131 samples, 28 parameters). Seasonalfluctuations were also studied. Arsenic ranged from 1–1340 µg L-1 (average 163 µg L-1), with48% exceeding 10 µg L-1. Elevated manganese levels (57% >0.4 mg L-1) are posing anadditional health threat to the 1.2 million people living in this area. With 350 people km-2potentially exposed to chronic arsenic poisoning, the magnitude is similar to Bangladesh (200km-2). Elevated arsenic levels are sharply restricted to the Bassac and Mekong River banksand the alluvium braided by these rivers. Arsenic in this province averaged at 233 µg L-1

(median 100 µg L-1), while concentrations to the west and east of the rivers were <10 µg L-1.Arsenic release from Holocene sediments between the rivers is caused by reductivedissolution of metal oxides. Regions exhibiting low and elevated arsenic levels are coincidentwith the present low relief topography featuring gently increasing elevation to the west andeast of a shallow valley - understood as a relict of pre-Holocene topography.

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(4) High concentrations of arsenic in drinking water result in the highest knownincreases in mortality attributable to any environmental exposure

Allan H. Smith, Craig Steinmaus, Yan Yuan, Jane Liaw, Meera M Hira-Smith Allan Smith <ahsmith@berkeley.edu>Craig Steinmaus <craigs@berkeley.edu>mmhsmith@berkeley.edu,janel <janeliaw@berkeley.edu>yanyuan@uclink.berkeley.edu

Arsenic in drinking water continues to surprise. Invisible, tasteless and odorless, yet in thelong term 1 in 10 persons with high concentrations of arsenic in their drinking water will diefrom it. Other environmental exposures do not result in commensurable mortality risks.

The major long term health impacts of arsenic in drinking water surprisingly occur in thelungs. And arsenic provides the first clear-cut evidence that early life exposure to anenvironmental toxin can result in marked increase in mortality in young adults from lungcancer.

Cancer is not the only long-term pulmonary outcome. In India subjects with arsenic-causedskin lesions have a 10-fold increased prevalence of bronchiectasis compared with subjectswho did not have skin lesions (RR=10; 95% confidence interval 2.7–37). In Chile youngadults aged 30-49 have a more than 40-fold increase in mortality from bronchiectasis if theyhad in utero exposure to arsenic in drinking water (RR=46.2, CI 21.1-87.7, p<0.001).

Most countries have some water sources with increased arsenic concentrations. The markedincrease in long term health risks which greatly exceed those from any other drinking watercontaminant mean that all drinking water sources in the world should be tested for arsenic.

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(5) Expertise and environmental justice

Peter J. Atkins*, M. Manzurul Hassan† and Christine E. Dunn** Department of Geography, University of Durham, Durham DH1 3LE† Department of Geography and Environment, Jahangirnagar University, Savar, Dhaka -1342, Bangladesh Peter J. Atkins p.j.atkins@durham.ac.ukmanzurulh@gmail.com

This paper will address the problem of arsenic in groundwater in the context of debates aboutexpertise and legal geographies. The case of Sutradhar v NERC, which was tested recently inthe British courts, is taken as a starting point for a commentary on the notion of ‘proximity’between science/technology and its clientèle in the global south. In legal terms there was analleged ‘tort’ – a damage and a liability – resulting from a regime of environmentalmonitoring that did not pick up the presence of arsenic in groundwater. The House of Lordsdecided that there was no case to answer but there are broader points about expertise,consultancy and ‘duty of care’ that remain, particularly for countries such as Bangladeshwhere much foreign aid is devoted to understanding and mitigating its many environmentalhazards. Although torts have a long history in Anglo-Saxon common law, there is littleprecedent for international litigation of this sort and new styles of legal argument arerequired.

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SESSION 2 - Inter-relationships of Arsenic, Soil, Food, Water andHealth

(1) Factors affecting arsenic accumulation and speciation in rice

Meharg AA, Williams PN, Ademoko E, Solaiman AR, Feldmann J, Raab AA.meharg@abdn.ac.uk

Rice generally has grain arsenic levels about 10 fold higher than other grains, and in thisdietary staple of SE Asia, ionorganic arsenic levels in rice make a major contribution tohuman arsenic intake. As the paddy fields of Bangladesh and West Bengal are widelyirrigated with arsenic contaminated goundwaters, the factors affecting grain accumulation andspeciation in rice were investigated. A detailed field survey of Bangladesh revealed that thereis considerable spatial, temperal and plant physiological control on rice accumulation andspeciation in grain. This is due to stong spatial patterns of arsenic loadings in irrigated paddyfields, strong spatial patterns in arsenic bioavailability within paddies, and a strongrelationship between arsenic levels in the shoot and grain export. Comparison of arsenicuptake with that of wheat and barley proves that rice is highly susceptible to arsenicaccumulation with a shoot/soil transfer factor of around 1, more than 10 fold higher than forother grain crops. This is probably due to rice being anaerobically cultivated, which greatlyalters arsenic dynamics in soil solution.

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(2) Arsenic accumulation in irrigated paddy soils and possible mitigation methods

Hugh Brammer, c/o Department of Geography, University of Cambridgeh.brammer@btinternet.com

Irrigation with arsenic-contaminated groundwater is adding arsenic to soils in Bangladesh,India and some other countries in south and south-east Asia. The added arsenic graduallyaccumulates in the topsoil, and amounts now appear to be reaching levels toxic to rice insome soils that have been irrigated with highly-contaminated water for 10-20 years or more.Arsenic accumulations vary considerably between and within tubewell command areas. Theseare factors that need to be considered in water, soil and crop sampling. Practical mitigationand rehabilitation methods will vary from place to place according to local environmental,economic and cultural conditions, and may be costly to apply. Possible methods include:water treatment; providing an alternative safe water supply; changing crop agronomy; soiltreatments to reduce arsenic uptake by crops; removing contaminated topsoils; and growinghyperaccumulator plants. In badly affected countries, water, soil and agricultural institutionswill need strengthening to survey and assess the scale of arsenic contamination and to test andimplement appropriate mitigation measures.

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(3) Monte Carlo Based Quantification of Increased arsenic-related cancer risk due torice intake in West Bengal, India.

Ms Debapriya Mondal, Postgraduate Researcher, School of Earth, Atmospheric andEnvironmental Sciences, University of Manchester, U.K.debapriya.mondal@postgrad.manchester.ac.ukDr Dave Polya, Senior Lecturer, School of Earth, Atmospheric and Environmental Sciences.University of Manchester, U.K.

The importance or otherwise of rice as an exposure route of arsenic for people living inBengal and other areas impacted by hazardous arsenic bearing groundwaters is currently indispute. We use combined field, laboratory and computational methods to quantitativelyestimate the overall increased cancer risk due to ingestion of arsenic-bearing rice in adults intwo typical arsenic impacted districts in West Bengal. The distribution of chronic dailyintakes (CDI) of arsenic in the study group has been estimated by Monte Carlo simulationfollowing fitting of probability curves to measured distributions of arsenic concentration inrice, rice ingestion rates; and body weight. Estimated target cancer risks for an exposureduration of 10 years were then calculated using the USEPA (1989) one hit model. The meanincreased life-time cancer risk, over and above that due to uptake of arsenic from drinkingwater, was 4.5 x 10-4, higher than the 10-4 to 10-6 range typically used by the USEPA to guidedetermination of regulatory values. Furthermore, about 5% of the cancer risks calculated weregreater than 10-3. On-going work is focused on determining the nature of particular sub-groupsof the population that may have significantly higher cancer risks than the mean.

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(4) Evaluation of human exposure to inorganic arsenic in populations of northernArgentina

Calatayud, M.,1 Devesa, V.,1 De Bovi-Mitre, G., 2 Farias, S., 3 Gimenez, M. 4 Villaamil, E. 51 Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Apdo 73, 46100 -Burjassot, Valencia, Spain. E-mail: vdevesa@iata.cis.es2 Facultad de Ingeniería - Universidad Nacional de Jujuy - Gorriti 237, San Salvador de Jujuy,Provincia de Jujuy, Argentina.3 Comisión Nacional de Energía Atómica (CNEA), Gerencia de Tecnología y MedioAmbiente, Av. Gral. Paz. 1499 (B1650KNA) San Martín, Provincia de Buenos Aires,Argentina.4 Cátedra de Química Analítica. Facultad de Agroindustrias. Universidad Nacional delNordeste, Argentina. 5 Cátedra de Toxicología y Química Legal. Facultad de Farmacia y Bioquímica, Universidadde Buenos Aires, Argentina.

Argentina is one of the Latin American countries with the highest environmental arsenicconcentrations. It has been estimated that over one million inhabitants, fundamentally in ruralareas, depend on groundwater with arsenic concentrations in excess of 50 µg/L. One of themost affected areas is located on the Chaco-Pampean Plain, in the northern part of thecountry, where for over 20 years the population has shown symptoms of chronic endemicarsenicism. The present study evaluates human exposure to inorganic arsenic in populationsof two provinces in the mentioned geographic setting: El Chaco and Santiago del Estero. Anassessment has been made of the ingestion of inorganic arsenic through drinking water andraw and cooked foods in several families. The duplicate rations method has been used forfood sampling. The results obtained - the first of their kind in Argentina - indicate ingestionfar above the toxicological reference value recommended by the FAO/WHO (ISTP = 15 µginorganic arsenic/kg body weight /week). This implies a serious public health problem in theregion. Urgent implantation of the opportune palliative measures by the national authorities isthus required.

Acknowledgments: The authors are indebted to projects CYTED 105PI0272 and AECIA/4883/06 for the help received in conducting the present study.

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(5) Suffering for water, Suffering from water: Gendered and Classed dimensions ofArsenic Poisoning in Bangladesh

Dr. Farhana Sultana Lecturer, King's College Londonfarhana@jonosc.com, farhana.sultana@kcl.ac.uk

The arsenic crisis in Bangladesh poses a significant water management challenge in thecountry in that it involves not only complexities of water provision and water managementinstitutions, but also involves interlinked health issues and social implications. Pay attentionto gender and class issues in water access, use and control highlights how the arsenicpoisoning of drinking water affects various groups of society differently. In this paper, I bringforth the various ways by which rural Bangladeshis are simultaneously suffering for water, aswell as suffering from water. An explicit attention to gender and class issues is needed tonotice and reveal such issues, which may not always be apparent or captured otherwise,thereby highlighting the importance of focusing on the multi-layered and interconnectedsocial, economic, cultural and political dynamics involved. Such a perspective of highlightingthe social implications are often drowned out by the over-emphasis on technocratic solutionsand need greater attention from researchers, policy-makers, and project implementers.

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SESSION 3 - Hydrochemistry and management of groundwater

(1) Arsenic in groundwater: simplicity and complexity.

John M. McArthurProfessor of Geochemistry, Earth Sciences, University College LondonGower Street, London WC1E 6BT. j.mcarthur@ucl.ac.uk

The widespread problems posed by pollution of groundwater by arsenic require us tounderstand how arsenic gets into groundwater, moves through aquifers, and in some instancesis immobilized within them. When concentrations of arsenic are high (>200 µg/L)identifying the source is simple – it is either reductive dissolution of iron oxides, geothermalsources, or weathering of sulphide ores. Each mechanism has characteristic signaturesallowing identification. Subsurface weathering of ores to give identifiable pollution ingroundwater is rare, but mining activity on the surface can generate acidic, arsenic–rich,waters that can invade aquifers locally to poison groundwater.

When arsenic concentrations in groundwater are <100 µg/L, matters of source, transport andfate are much harder to determine. Additional mechanisms, such as competitive exchange ofarsenic anions with other anions such as hydroxide, and weathering of silicates and tracesulphides may be important. The balance of influences will change along a flowpath tofurther complicate matters.

Reduction of iron oxide is a microbial process and the source of organic matter to drive thereaction is arguably the most important, and least known, part of the process. Competitiveexchange is not biologically mediated, and has been studied much in the laboratory, but atarsenic concentrations that are far higher than those found in nature, so there is a problemwith interpretation. Silicate weathering has been studied little. Such issues will be reviewedin this presentation.

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(2) Mobilisation of arsenic in the groundwater of the Blackfoot Disease area in Chia-Nan Plain, southwestern Taiwan

Jiin-Shuh Jean Professor Department of Earth Sciences, National Cheng KungUniversityBibhash Nath Postdoctoral researcher Department of Earth Sciences, National Cheng KungUniversityLi-O Weng Undergraduate student Department of Earth Sciences, National Cheng KungUniversityChia-Chuan Liu PhD student Department of Earth Sciences, National Cheng Kung UniversityYing-Wen Yang PhD student Department of Earth Sciences, National Cheng KungUniversityjiinshuh@mail.ncku.edu.tw

The adsorption/desorption of arsenic and its mineral species were investigated in theBlackfoot Disease (BFD) area of Chia-Nan Plain, southwestern Taiwan. In this study,groundwater samples from twenty-five wells were collected and analyzed in May 2005. Theresult shows that all the groundwater samples contained considerable amounts of arsenic,iron, manganese, and strontium (0.015 to 0.796 mg/L, 0.036 to 4.43 mg/L, 0.025 to 0.901mg/L, and 0.062 to 6.22 mg/L, respectively). The arsenic speciation studies show that thereduced arsenic species (As-III) is widely distributed, with reduction ratio ranged from 57 to99%, suggesting reducing nature of the BFD groundwater. The saturation indices computedby PHREEQC were positive for iron assemblages (i.e., iron hydroxides, goethite, hematite,jarosite, maghemite, and magnetite), while negative for arsenic assemblages (i.e., arsenolite,native arsenic, and scorodite). This demonstrates that the iron species had been precipitated,while arsenic species was dissolved in groundwater. Some bacterial strains were also isolatedfrom groundwater, which includes Acinetobacter radioresistens,Bacillus benzoevorans,Bacillus circulans, Brevundimonas sp., Exiguobacterium aestuarii, Glacial ice bacterium, etc.The adsorption/desorption experiment revealed that the arsenic could be adsorbed upto 44%onto iron hydroxides at lower concentration level for initial arsenic (5 mg/L), while theadsorption is relatively low (29%) for 10 mg/L of initial arsenic.

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(3) Arsenic enrichment of ground water at two regions of the Chacopampean Plain,northwest Argentina

Ondra Sracek1, María Gabriela García2

1 OPV s.r.o., Bĕlohorská 31, 169 00 Praha 6, Czech Republic (srondra@yahoo.com)2 Centro de Investigaciones Geoquímicas y de Procesos de la Superficie, FCEFyN,Universidad Nacional de Córdoba, Av. Vélez Sarsfield 1611, X5016CGA Córdoba,Argentina

High concentrations of arsenic have been encountered in ground water of the ChacopampeanPlain (CPP). Two regions have been studied: Santiago del Estero in semiarid central CPP andmore humid Tucumán at western limits of CPP. In both regions concentrations of dissolvedAs may reach values above 1,000 μg/l and high As concentrations are linked to shallowloessic sediments (upper 30 m of sedimentary sequence). There is a positive correlationbetween dissolved As and Na and HCO3 concentrations. Also, there is positive correlationbetween As and several oxyanion-forming elements including V, F, B, and Mo present involcanic ash in loessic sequence. Primary source of arsenic in ground water cannot bedetermined unequivocally, but highly weathered glass present in volcanic ash is a principalcandidate. Contents of ferric iron extracted by the oxalic extraction step are low because thereis a limited amount of oxidizable ferrous iron minerals in volcanic ash of acid composition.Thus, adsorption capacity of solid phase for As is quite limited and may be further decreasedby competition with other oxyanions for adsorption sites. Conditions in shallow aquifer aregenerally oxidizing and arsenic is present mostly as As(V). However, in the proximity of theSalí River in Tucumán As can be released as a consequence of the penetration of surfacewater contaminated by organic wastes and causing reductive dissolution of ferric mineraladsorbents in the neighboring aquifer. Similarly, high concentration of DOC with a potentialimpact on As mobilization were observed in the proximity of unlined irrigation canals atSantiago del Estero.

In Santiago del Estero high As concentrations seem to be linked to slow ground water flowzones with long ground water residence times and high pH (up to 9.0) and TDS values. InTucumán, As concentrations seem to increase from west towards east along with direction offlow, decreasing precipitation and longer residence time of ground water that recharges at themountain front of Sierra del Aconquija at western limits of the region. Many of these findingsare also applicable to other sites in Argentina with high dissolved As concentrations like LaPampa south of both studied sites.

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(4) Towards a regional characterisation of the ‘deep aquifer’ in southern Bangladesh

Mohammad Hoque PhD researcher UCLWilliam Burgess Lecturer UCLMatin Ahmed Professor Dhaka UniversityS. M. Ihtishamul Huq DPHE (Department of Public Health Engineering), Bangladeshm.hoque@ucl.ac.uk, kazimatin@yahoo.com, G-Howard@dfid.gov.uk, william.burgess@ucl.ac.uk

In southern Bangladesh and West Bengal it has long been known that a deeper aquifer,separated from the shallow, arsenic-bearing groundwater system by an effective aquitard atca. 150 m depth, occurs in places. This deep aquifer has been exploited sustainably to providewater supplies for individual towns – eg at Khulna where for over 20 years the aquitard hasprotected the deep aquifer from incursions of salinity and arsenic occuring in the shallowaquifer. Nevertheless, for a variety of alternative hydrogeological scenarios, exploratorymodels demonstrate the vulnerability of the deep aquifer to vertical leakage from the shallowsystem, limiting its potential to act as an ‘arsenic safe’ source of water. The lateral variabilityand regional extent of the aquitard is unknown, and many questions concerning the deepaquifer remain to be answered. We present empirical descriptions and preliminaryconceptualisations of the deep aquifer environment from current research at individual sitesacross southern Bangladesh, incorporating: lithostratigraphy, sedimentology andhydrostratigraphy from geological and geophysical logs and head measurements, and profilesof groundwater chemistry, groundwater age and groundwater isotopic character forindications of groundwater flow. Uncertainties, and their implications for the viability of thedeep aquifer as a source of arsenic-safe water, will be emphasised.

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(5) Arsenic-contaminated aquifers: a study of the Ganga levée zones in Bihar, India

Dr. Ashok Ghosh, Prof.-in-Charge, Department of Environment and Water ManagementA.N.College [Magadh University], Patna, India ghosh51@hotmail.comProf. Shatrunjay K. Singh, Coordinator, Dept. of Environment and Water ManagementA.N.College [Magadh University], Patna, IndiaDr. Nupur Bose, Lecturer, Dept. of Geography, A.N.College [Magadh University], Patna,IndiaDr. Sunil Choudhary, Reader, Dept. of Botany, T.M.Bhagalpur University, Bhagalpur, India

'In Bihar Plains, ground water is the most important source of drinking and irrigation water.The purpose of this interdisciplinary study, undertaken along the levee of river Ganga in theMid Ganga Plain, was to determine the existence and intensity of arsenic contamination inaquifers being tapped for direct and indirect ingestion of the properties of the region’s groundwater, in the four districts of Bihar [India], i.e., Patna, Bhojpur, Vaishali and Bhagalpur. Themethodology involved formulation of a protocol for arsenic detection in ground water, use ofField Test Kits for initial detection, obtaining GPS coordinates of arsenic hotspots for spatialanalysis of the problem, and confirmatory testing of arsenic hot samples by U.V., and AtomicAbsorption Spectrophotometry. Water samples of 28000 private and government owned handpumps were tested. Many arsenic hotspots were detected in all the four districts, thecoordinates of which were recorded by GPS. Arsenic contamination up to 1861 ppb. wasfound in the western district of Bhojpur, against the W.H.O. permissible limit of 10 ppb. Thegreatest frequency of contaminated hand pumps was noted in the eastern district ofBhagalpur. Sharp spatio-temporal variations of contamination levels were detected in thisdensely populated study belt.

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SESSION 4 - Mitigation and sustainability of water supply inArsenic-affected areas

(1) Identifying the preferred arsenic mitigation options in Bangladesh

Dr Guy Howard, Policy Advisor, Department for International Developmentg-howard@dfid.gov.ukDr Feroze Ahmed, Professor, Bangladesh University of Technology

Arsenic mitigation in Bangladesh has focused on the provision of arsenic-safe water supplies.The use of surface water and very shallow groundwater was encouraged in the NationalPolicy for Arsenic Mitigation despite limited assessment of potential risk substitution. In2004/5 a risk assessment was undertaken of a statistically representative sample of watersupplies to estimate the disease burden, based on DALYs, associated with the four principalwater technologies. Deep tubewells had the lowest disease burden and are the preferredtechnology from a public health perspective. Dug wells and pond sand filters showed elevatedrisks and require disinfection to meet acceptable levels of performance. Communities preferdeep tubewell technology and in practice they are the most commonly used. The findingsillustrate that the stated preference in Government strategy documents should be revisited.The risk assessment also flagged the necessity of improving the currently inadequateknowledge of the quality of water resources in Bangladesh. The full extent of arsenic-safedeep aquifers and their recharge mechanism across Bangladesh remains unclear and availablewater quality data are of poor quality. As some surface water sources will have to be used,further work is required to identify the true availability of suitable surface water sources.

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(2) Surveillance Program to Monitor the Use of New Water Sources in Rural andRemote Areas

Meera M Hira-Smith, Jane Liaw, Yan Yuan, Sekhar Pal, Cynthia Green, Alpana HiraDavidson, Timir Hore, Allan H Smithmmhsmith@berkeley.edu

Our experience in West Bengal, India, where large numbers of people have been exposed toarsenic in tube-well water, is that interventions to provide arsenic-safe water in localcommunities require on-going surveillance and monitoring. Without continuing monitoringand education programs, people may revert to their previous sources of water with the newsources being underutilized, and in some cases becoming non-operational. Since 2001,Project Well has constructed modified dugwells in a pilot program to provide arsenic-safewater to small, community-groups in West Bengal. Over the last six years, we have designedand implemented a Follow-Up/Surveillance Program, to monitor and evaluate the utility ofthe dugwells. The Follow-Up program includes regular monitoring of the wells andinterviews concerning the use of dugwell water that has enabled Project Well to assess causesof dugwell underutilization. Modifications that have been implemented include chlorinationof the water to reduce bacterial contamination. Interview surveys discovered thatconsumption reduced mainly due to chlorine odor that the villagers were not familiar with.The dose of chlorine has since been reduced and the remaining chlorine odor is removed withearthen filters. Dugwell water use has since increased. We conclude that all local small-scalecommunity water interventions require ongoing monitoring.

Meera M Hira-Smith, Ph.D. (Geography)Founder and DirectorProject Wellweb site: http://www.projectwellusa.org/Phone: (510) 530-6050

ResearcherUniversity of California, Berkeley140 Warren HallBerkeley, CA 94720-7360Tel: 510/843-1736 / Fax: 510/843-5539Web site at: http://socrates.berkeley.edu/~asrg/

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(3) Community Based Project to Mitigate Arsenic Pollution in West Bengal andJharkhand, India

Dr. Sudhanshu Sinha, Diptarup Kahali and M. Satyanarayana (ssinha@icefindia.org)

Alarming level of arsenic in the groundwater of eight districts of West Bengal and 2 districtsof Jharkhand in East India has become a serious health hazard. The number of peoplesuffering from skin lesions, muscular disorder and even cancer, is constantly going up. This isan acute 'environmental health' problem since the rural population in these districts is solelydependent on groundwater for drinking, bathing and cooking.

The source of the problem is geological in origin, which has aggravated due to excessivewithdrawal of groundwater for paddy cultivation in the wake of the green revolution of the1970s. India-Canada Environment Facility (ICEF), a development organization supported byCIDA along with All India Institute of Hygiene and Public Health (AIIH&PH), a premierhealth institution of Government of India launched the first community-based arsenicmitigation project in July 1999 which ended in March 2007. ICEF's intervention hasshowcased a viable rural model that can be replicated in the Indian sub-continent.

The aim of this project has been to manage the problem with the help of local NGOs in 400villages in Bengal, and 10 villages in Jharkhand. The project objective has been to empowerthe community to mitigate the problem through low-cost, low tech, sustainable solutions.

Dr. Sudhanshu Sinha Senior Project Officer India-Canada Environment Facility (ICEF) B - 79, Sector - 53, Noida - 201 303, Uttar Pradesh, India Mobile: 981077-9159

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(4) Analysis of net impacts on disease burden of arsenic mitigation in Bangladesh

GeorgeAdamson, University of ManchesterDavid Polya, Senior Lecturer University of Manchester david.polya@manchester.ac.uk

It has been increasingly recognised that calculation of the disease burden due to populations,such as in Bangladesh, extensively using hazardous arsenic bearing well waters, mustexplicitly account for the trade-off between diarrhoeal disease incidence and that of arsenic-related diseases. This is because it is likely that moves to alternative drinking water sources,be they surface waters or even more distant groundwaters, without further mitigation wouldresult in a concurrent increase in diarrhoeal disease.

Our model, based upon that of Lokuge, suggests that mitigation simply involving thesubstitution of well water sources with As > 50 ppb would have a net positive impact ondisease burden, as determined by Disability Life Adjusted Years (DALYs), but that the samemitigation for all the population exposed to well water arsenic as low as 10 ppb would, incontrast, have a negative impact. However, uncertainties in the dose-response relationship forarsenic uptake and the non-malignant high incidence conditions diabetes mellitus andischemic heart disease means that the net impact on DALYs of such mitigation cannot bereliably determined at this time.

These calculations nevertheless emphasise the requirement for multiple mitigation strategies,including those directed at ensuring the microbiological safety of alternative water supplies.

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(5) Road to Sustainable Arsenic Management in Bangladesh: The Deep Aquifer Issues

Professor K M Ahmed Professor, University of DhakaDr Guy Howard Engineering Advisor DfIDMr R Ogata Arsenic Mitigation Advisor JICA, DhakaS M Ihtishamul Huq Department of Public Health Engineering, Dhaka

g-howard@dfid.gov.uk, kazimatin@yahoo.com; kmahmed@univdhaka.edu

The extent and severity of arsenic occurrence in Bangladesh is well-known. Although variousinitiatives have been taken since 1993, only a small proportion of the exposed populationhave access to a safe water option. Deep tube wells supply more than 90% of the safe water inarsenic affected areas; risk assessments and functionality surveys confirm that that this optionhas lowest risk, and is most sustainable.

The Department of Public Health Engineering (DPHE) has initiated the development of anational deep aquifer database with preliminary maps. Although hundreds of thousands ofdeep tube wells are in operation, availability of good quality borelogs is very limited.Creation of the database is a step forward towards sustainable management of the deepaquifer. We shall critically review the concept of deep aquifer in Bangladesh; outline how thedeep aquifer database was established; present preliminary deep aquifer maps; and discuss themajor issues related to the sustainable management of the deep aquifer both for arsenicmitigation and as a vital natural resource for Bangladesh. We shall also highlight the existingpolicy and regulations regarding the deep aquifer and outline a management strategy to securethis strategic water resource for the future.

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SESSION 5: SHORT CONTRIBUTIONS AND DISCUSSION

(1) Geochemistry and speciation of solid and aqueous phase arsenic in the Bengal DeltaPlain aquifers

Bibhash Nath Postdoctoral Researcher Department of Earth Sciences, National Cheng KungUniversity, TaiwanDebashis Chatterjee Associate Professor Department of Chemistry, Kalyani University, IndiaJiin-Shuh Jean Professor Department of Earth Sciences, National Cheng KungUniversity, TaiwanProsun Bhattacharya Associate Professor Department of Land and Water ResourcesEngineering, Royal Institute of Technology, SwedenKazi Matin Ahmed Professor Department of Geology, University of Dhaka, Dhaka 1000,Bangladeshbibhash12@yahoo.com

The groundwater chemistry of Bengal Delta Plain (BDP) is mostly alike for shallow aquifers,however, depends largely on the geospatial signatures, sediment texture and mineralogy. Themajor pathway of high arsenic (As) concentration in groundwater is the reductive dissolutionof the "As-traps" (mostly sedimentary iron-oxides and hydroxides) under local reducingcondition. The high As aquifers are largely in the low land areas intersparsed with low arseniczones. The release of redox sensitive species (As, Fe, Mn) is the function of bioavailableforms of iron oxide, concentration as well as distribution of organic matter and availability ofelectron donors in the alluvium. Aqueous speciation indicate that the ratio of As(III)/(V) isvarying with varied combination of As(III)/Astot over a large geographical area of BDP.Water chemistry reveals that siderite and vivianite are commonly in supersaturated stage(insoluble phases) in the groundwater, that further confirms by solid phase chemicalpartitioning. The concentration and distribution of siderite/vivianite is also important inexplaining large-scale and variable aqueous As species in groundwater. Solid phase chemicalpartitioning shows that the arsenic is associated with amorphous Fe-oxide together withsurface bound PO43- in coarser sediments and is playing an important role in Asmobilization.

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(2) The mobilization of arsenic in groundwater and arseniasis from the Hetao Area,Inner Mongolia

H. ZhangSchool of Environmental Science and Engineering, Shanghai Jiaotong University, 800 DongchuanRd., Shanghai 200240, P.R. China. Tel: +86-21-54748942, Fax: +86-21-54740825, e-mail:huizhang@sjtu.edu.cn

In Hetao Area, Inner Mongolia, China, Quarternary alluvial aquifers used for public water

supply are contaminated by naturally occurring arsenic, which is heavily affecting the health

of the 180,000 people there. A lot of efforts to improve drink water have been carried out

since 1990s. But the arsenic effects for resident health cannot be avoided effectively. This

indicates that the cognition, which the arsenic is derived from rich arsenic aquifers formed

under the anoxic conditions, for arsenic contamination in the groundwater in Hetao Area may

not be right. Our study shows that the contaminant derives from the upper reaches where

groundwater is high in arsenic. The concentration of As in the water reduces from 0.251 ml/L

to 0.005 ml/L along the working line by 44 km. Arsenic concentration in the soil varies

gradually at the working lines along the flow direction as follows: from 22.0 mg/kg to 9.6

mg/kg, from 20.0 mg/kg to 7.9 mg/kg’, and from 18.0 mg/kg to 9.9 mg/kg at work lines by

52, 68, and 40 km respectively. Strontium isotope data of well water, which is used for

drinking by residents, and the variation of arsenic levels in resident people hair suggest that

mobilization of the arsenic from the upper reaches, front Yin Mountains, to the alluvial

aquifers of the lower reaches may be responsible for the current health crisis of resident

arseniasis. Potential solutions should be: the treatment of mining water before drainage in

upper reaches, finding groundwater in too depth to be reached by rich arsenic water from

mining and weathering in upper reaches or the groundwater under aquifuge stratum, and

treatment of groundwater as drinking water at the point of use or in the water supply plant.

Key Words: Arsenic poisoning; Groundwater; The Hetao Area, Inner Mongolia

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(3) VULNERABILITY OF POPULATION EXPOSED TO ARSENICCONTAMINATION IN THE MID GANGA PLAIN OF BIHAR, INDIA

Dr. Ashok Kumar Ghosh, Prof.-in-Charge, Dept. of Environment and Water ManagementA.N.College, Patna nupur.bose@gmail.com

Dr. Nupur Bose, Lecturer, Dept. of Geography, A.N.College, Patna, IndiaDr. Narendra Kumar Roy, Resource Person, Dept. of Environment and Water Management

A.N.College, Patna, BiharDr. Ajay Upadhyay, Resource Person, Dept. of Environment and Water ManagementA.N.College, Patna, IndiaMr. Amardeep Singh, Research Scholar, Dept. of Environment and WaterManagement A.N.College, Patna, IndiaMr. Sushant Kumar Singh, Research Scholar, Dept. of Environment and Water Management

A.N.College, Patna, India

Arsenic contaminated aquifers, being used for direct and indirect human consumption, havesevere health implications among the rural population in the state on Bihar, India. This studycovered a 10 km. belt along the Ganga river in the four districts of Bhojpur, Patna, Vaishaliand Bhagalpur. The purpose of this research was to obtain the distribution and quantum ofhuman population at risk of arsenic poisoning and population composition characteristics ofthe arsenic-affected belt. The methodology adopted was based upon self-generated andconfirmed primary data on abnormally high arsenic concentration in ground water rangingfrom above 10 ppb. to 1861 ppb. Percentage of hand pumps testing with more than 10 ppb.arsenic content were calculated. This data was compared with the Census 2001 data to obtainestimates of affected population, while Topographical and Administrative Block Maps of allfour districts were referred to for studying the spatial pattern of this population. The resultshowed that approximately 1,537,426 persons [about 47% of the population] residing in thestudy belt are at risk. In Bhagalpur study belt, the vulnerability extends to more than 75% ofthe population. Symptoms of arsenic poisoning are widespread, especially among childpopulation. Appropriate mitigation strategies are yet to be undertaken in this study area.

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(4) Occurrence and Health Effects of Arsenic in China

Zheng, Y.1,2, D.-J. Sun3, G.-F. Sun4, G.-Q. Yu3, S-X. Wang5, A.-H. Zhang6, D. An7, D.-S. Li7

and O. Odediran8

yan.zheng@qc.cuny.edu1Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA2Queens College, City University of New York, Flushing, NY 11367, USA3The Center for Endemic Disease Control, Chinese Center for Disease Control andPrevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R.China. 4Department of Environmental and Occupational Health, College of Public Health, ChinaMedical University, Shenyang, Liaoning, PR China5 Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, Shanxi 041000,China6Department of Toxicology, School of Public Health, Guiyang Medical University, Guizhou,550004, PR China7Guizhou Center for Disease Control and Prevention, 73 Bageyan Road, Guiyang 550004,Guizhou, China8UNICEF, Water and Environment, New York, USA

China has well-documented As endemics areas with high occurrence rates of arsenicosis possibly dueto longer histories of exposure and biomedical investigations dating back to the1980s. Recently, fivearticles that report the health effects of As in the exposed population and describe the mitigationapproach used to reduce As has appeared as a mini-monograph in Environmental Health Perspective.In a survey of 135,492 individuals in eight provinces, 10,096 cases of arsenicosis with variousdegrees of skin lesions were identified. This arsenicosis occurrence rate of 7.5% is likely anoverestimate because the survey focused more on known and suspected endemic areas of arsenicosis.However, it is worth noting that the percentage of arsenicosis cases correlates positively with thepercentage of wells containing > 50 g/L of As (R2 = 0.70). For example, if a province had onaverage 10% of wells containing > 50 g/L of As, then the occurrence rate of arsenicosis is also ~10%. In Inner Mongolia, a comparison of urinary As metabolites in children and adults showed thatchildren had a higher percentage of dimethylarsenic acid (DMA) than adults. In Shanxi, an ecologicalstudy of 720 children between 8 to 12 years of age showed that IQ scores decreased from 105 ± 15for the control group, to 101 ± 16 for the medium-As group with 142 ± 106 μg/L (p < 0.05), and to 95± 17 for the high-As group with 190 ± 183 μg/L (p < 0.01). In Guizhou, a population exposed to mglevel of As originated from coal-fired stoves showed that long-term As exposure may be associatedwith damage of chromosomes and DNA, gene mutations, gene deletions, and alterations of DNAsynthesis and repair ability. Fortunately, health education to that population has resulted in dramaticdecrease of exposure, reflected in reduction of urinary As concentrations by a factor of 4. A strong associate between As and Au-deposits in China have been noted. This association is used toillustrate the heterogeneous nature of As distribution in the crust and to shed light on the tectonicenvironment that lead to anomalies of As concentrations in source rock. Further geochemicalinvestigations are much needed to understand the heterogeneity of As distribution in the crust, and itssignificance on occurrence of elevated groundwater As in sedimentary aquifers. However, thesystematic geographic distribution of As-rich minerals in Au deposits along the orogeny belts wassuggestive that As anomalies in whole rock may be more wide spread, the geographic extent of suchAs anomalies in whole rock remain to be defined by more whole rock analyses. The distribution ofAs in soil from on-going high density sampling in China can be used to identify promising areas forwhole rock analyses. An intriguing prediction of the conceptual model of As distribution in the crustis that rifting and pull apart sedimentary basins in China are more prone to have groundwater Asproblems if they are down gradient from high As source rocks.

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(5) “Mass Arsenic Poisoning of Rural Bangladesh - Health impact and Communitybased mitigation of patient management and Safe Drinking water, DCH Experience.”

- Mahmuder Rahman, Quazi Quamruzzaman, Jabed Yousuf, Golam Mostofa, Altab Elahi,Afroza Khatun, Sharmina Banu and Ronjit Halder

Prof. Mahmuder RahmanTrust Co-Ordinator-DCHTDhaka Community Hospital190/1 Bara Moghbazar, Wireless RailgateDhaka – 1217Bangladeshdch@bangla.net

Bangladesh is facing a massive health and environment problem along with other South and South-East Asia countries caused by groundwater arsenic contamination.

Millions of populations are affected. Thousands are now suffering from cancers, gangrene and otherserious health, social and environmental problem from arsenic poisoning.

In June 1996, Dhaka Community Hospital detected arsenic Patient in Paksey, Pabna district andpioneered the detection of Arsenic Contamination of drinking water and Arsenic health effects inrural Bangladesh. Dhaka Community Hospital conducted a limited field survey with School ofEnvironment Studies (SOES) of Jadavpur University, India and published its findings in a Nationalconference in January 1997 and established the evidence of mass arsenic poisoning of ruralBangladesh. Since then DCH conducted survey all over Bangladesh with various national,International and UN agencies and organised 6 international conferences. DCH was instrumental inmobilizing national and international interest and activities to counter these devastating health andenvironmental hazard facing millions of people in South and South-East Asia.

Pathophysiology of “Arsenicosis”, the term coined to define the disease manifested by chronicarsenic poisoning and its complications are still not clear to the medical profession. Researches havebeen initiated and lot more will be necessary in future to understand the nature of these disorders.

Dhaka Community Hospital has initiated a program of community based Arsenic Mitigation ofPatient management and Safe Drinking water in rural Bangladesh. This programme is being reflectedin National Arsenic Mitigation Policy and Action Plan and various organizations has taken up thismodel of Arsenic mitigation programme and are being implemented.

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(6) The distribution of arsenic in groundwater in five states of India and geochemicaldata from an arsenic-affected area of Ballia District, Uttar Pradesh

Ross Nickson, UNICEF Kolkata, IndiaDr. Nalini Sankararamakrishnan, Indian Institute of Technology, Kanpur, India

Testing of groundwater used for drinking for arsenic has been undertaken more widely bystate governments in several states of India in recent years with the support of UNICEF.Available data for five states are discussed and this provides the most up-to-date picture ofareas known to be affected by arsenic in groundwater in the Indian portion of the Ganges-Brahmaputra river basin. In West Bengal, water from 132,262 government installedhandpumps in 8 districts has been tested and overall 25.5% of samples were found to containarsenic at concentrations greater than 50 µgl-1 and 57.9% at concentrations greater than 10µgl-1. On the banks of the Brahmaputra in Assam, to date, samples from 5,729 governmenthandpump sources in 22 districts have been tested for arsenic. Overall, samples from 6.3% ofsources were found to contain arsenic at concentrations greater than 50 µgl-1 and 26.4% atconcentrations greater than 10 µgl-1. In Bihar, on the River Ganges upstream of West Bengal,66,623 sources from 11 districts have been tested and water samples from 10.8% of sourceswere found to contain arsenic at concentrations greater than 50 µgl-1 and 28.9% atconcentrations greater than 10 µgl-1. Upstream of Bihar in Uttar Pradesh, to date watersamples from 103,578 government installed handpump sources have been tested. 1.3% of thesamples tested were found to contain arsenic at concentrations greater than 50 µgl-1 and 8.6%at concentrations greater than 10 µgl-1. Finally in one district of Jharkhand, lying on theGanges alluvial plain between Bihar and West Bengal, 9,007 sources have been tested andwater samples from 3.7% of sources were found to contain arsenic at concentrations greaterthan 50 µgl-1 and 7.5% at concentrations greater than 10 µgl-1. In West Bengal all publicsources were tested in areas known to be affected by arsenic so these figures arerepresentative of the situation in 79 arsenic-affected blocks in 8 districts, not for the state as awhole. In Bihar, Uttar Pradesh, Jharkhand and Assam testing was focused on blocks adjacentto the river Ganges or Brahmaputra so again the percentage calculations are onlyrepresentative of the specific areas tested and not the state as a whole. Testing is ongoing inseveral states and the complete picture is yet to emerge in some areas. Arsenic ingroundwater is also known to occur in the state of Chattisgarh in a different geological settingto the alluvial plains of Northern India. This occurrence of arsenic is not covered here. Dataon the geochemistry of arsenic-affected groundwater in Ballia District in Eastern UttarPradesh will also be presented. The data indicate that the groundwater is generally lessreducing in nature than further downstream in the Ganges/Brahmaputra delta areas of WestBengal/Bangladesh and As(V) is present in appreciable concentrations. This has implicationsfor arsenic testing and implementation of arsenic treatment technologies.

Ross NicksonWater Quality SpecialistUnited Nations Children's Fund219/2 A.J.C. Bose RoadKolkata 700 017, Indiarnickson@unicef.org

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UNALLOCATED PAPERS

(1) The Effects of Geologic Deposits, Depth of Tubewell, Age of Tubewell, and Numberof Users per Tubewell on Groundwater Arsenic, Uranium, Manganese, Nickel,Antimony, Lead, Chromium, Iron, pH, Boron, Barium, Molybdenum, Selenium, andZinc in Western Bangladesh

Lawrence Mastera / Norwich UniversityRichard Dunn / Norwich UniversityDonald M. Maynard, P.E. / The Johnson Company, Inc.Seth H. Frisbie, Ph.D. / Better Life Laboratories, Inc. and Norwich UniversityErika J. Mitchell, Ph.D. / Better Life Laboratories, Inc.Ahmad Zaki Yusuf / Bangladesh Association for Needy Peoples ImprovementMohammad Yusuf Siddiq, Ph.D. / Bangladesh Association for Needy Peoples ImprovementRichard Ortega, Ph.D. / Université de Bordeaux 1Thomas Bacquart / Université de Bordeaux 1Bibudhendra Sarkar, Ph.D. / University of Toronto and The Hospital for Sick Children

Groundwater (drinking water) samples were collected from 4 neighborhoods in westernBangladesh (Bualda, Fulbaria, Jamjami, Komlapur). To the extent possible, the sampledtubewells in each neighborhood were distributed at 500-meter intervals along perpendicularaxes that radiated in 4 equal lengths from the center. Each neighborhood had 17 samplinglocations: 4 north, 4 east, 4 south, 4 west, and 1 in the center. Each sample was analyzed forarsenic (As), uranium (U), manganese (Mn), nickel (Ni), antimony (Sb), lead (Pb), chromium(Cr), iron (Fe), pH, boron (B), barium (Ba), molybdenum (Mo), selenium (Se), and zinc (Zn).In this study, As, U, Mn, Ni, Sb, Pb, and Cr, were found above WHO health-based drinkingwater guidelines in 33%, 48%, 75%, 3%, 3%, 1%, and 1% of these tubewells, respectively.Conversely, B, Ba, and Mo were not found above these guidelines. Satellite images andinterviews were used to determine the effects of geologic deposits, depth of tubewell, age oftubewell, and number of users per tubewell on the concentrations of these 14 elements in thisgroundwater.

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(2) Methodology for the determination of inorganic arsenic metabolites in urine

Calatayud, M., Devesa, V., Vélez, D., Montoro, R.Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Apdo 73, 46100 -Burjassot, Valencia, SpainE-mail: vdevesa@iata.cis.es

Recent studies in populations chronically exposed to inorganic arsenic have revealed acorrelation between the urinary arsenical species resulting from inorganic arsenic metabolism(AsIII, MMAIII, DMAIII, AsV, MMAV and DMAV) and the development of certain diseasesassociated with exposure to the toxic agent. This urinary profile could be used as a biologicalmarker of chronic arsenicism. The principal problem in determining these urinary metabolitesis preservation of the trivalent forms for the time elapsed between sampling and analysis.Many of the populations exposed to arsenic are located in isolated rural areas with pooroverland communications. Consequently, the development of a technique allowing the in situstabilization of these trivalent forms would be very interesting.

The present study develops a method for stabilizing arsenical metabolites, with their posteriorseparation and assay. Preservation of the trivalent arsenical species is based on the use of acomplexing substance, diethylammonium diethyldithiocarbamate (DDDC). The DDDC-trivalent species complex remains stable at room temperature for as long as required forsample transport. Selective extraction is carried out with carbon tetrachloride and sodiumhydroxide. The arsenical species are determined by HPLC coupled to atomic fluorescencespectroscopy.

Acknowledgments: This research was supported by project MEC AGL2005-00619. M.Calatayud received a Personnel Training Grant to carry out this work.

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(3) Synthesis of Knowledge to Develop Integrated Arsenic Mitigation Strategy in India

Atanu SarkarDepartment of Policy Studies, TERI University, The Energy and Resources Institute, IndiaHabitat Centre, Lodhi Road, New Delhi 110003, Indiaasarkar@teri.res.in

Arsenic contamination of groundwater has emerged as a major environmental health problemin India. Since the discovery of first arsenicosis case in 1982, significant progress in researchhas been witnessed in various disciplines. But, current mitigation strategy has essentiallytaken segmental approach without considering holistic view. Hence, the suffering of thepeople remains unabated and now it has serious socio-politico-economic implications.

The purpose of the paper is to distill and harvest the major scientific findings and casestudies, generated from various researches along with field-survey based data conducted intwo affected districts in India. It also develops evidence-based alternative concept withinterdisciplinary characteristics by forming a better matrix, which is expecting to have policyrelevance in changing socio-political landscape. Data analysis shows that there is a need ofintegration of current arsenic related issues, including population health and vulnerability(class, caste and gender based disparity), socio-economic impact, social resilience, naturalresource management, appropriate technology (water purification) in local context, ecologicaldamage (soil, crop, livestock), agro-trade policy and practice, institutions and participatorygovernance.

The strategy should begin with identification of stakeholders (including community) whowould undergo more rigorous social learning to design, implement and sustain integrated,polycentric, horizontal and adaptive approach.

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