The problem of arsenic in South East Asia, particularly Bangladesh is the largest identified man 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 drinking water?

(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 from some presently unknown cause?

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

Over two hundred instances of arsenic contamination of groundwater due to natural causes have been recognised from 60 countries in five continents. Arsenic is mobilised into groundwater through four common mechanisms: reductive-dissolution, alkali-desorption, sulphide oxidation, and geothermal action. In terms of impact, by far the most important is reductive dissolution, while alkali-desorption is the second most important. Evaporation may increase concentrations of arsenic initially generated by any of these mechanisms. Two main compensatory processes, adsorption and sulphate reduction, act to remove arsenic from groundwater. The mobilisation mechanisms operate in systematic geological–climatic associations. Two geological associations dominate the occurrence of arsenic. The first is with 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 and chemistry of the rivers. Although local factors may act to prevent arsenic contamination at individual locations, these associations allow regional and global predictions of where encountering arsenic-contaminated groundwater is most likely. Classified by mobilisation mechanism and geological–climatic association, the present distribution of arsenic-contamination appears seriously incomplete, with entire continents apparently lacking examples of some mechanisms. Such predictions have led to the identification of arsenic in alluvial and glacial aquifers on three continents. Regions judged to be at high risk, as opposed those merely lacking data, are identified. Testing groundwater in these regions should be a high priority.

Dr. Johanna Buschmann, Chemist, Eawag johanna.buschmann@eawag.ch
Mr. Michael Berg, Chemist, Eawag
Mrs Caroline Stengel, Lab Technician, Eawag
Mr. Mickey Sampson, Chemist, RDIC

Arsenic contamination of groundwater has been identified in Cambodia, where some 100,000 wells are used for drinking water needs. We conducted a comprehensive groundwater survey in the Mekong Delta, comprising an area of 3700 km² (131 samples, 28 parameters). Seasonal fluctuations were also studied. Arsenic ranged from 1–1340 µg L^-1 (average 163 µg L^-1), with 48% exceeding 10 µg L^-1. Elevated manganese levels (57% >0.4 mg L^-1) are posing an additional health threat to the 1.2 million people living in this area. With 350 people km-2 potentially exposed to chronic arsenic poisoning, the magnitude is similar to Bangladesh (200 km^-2). Elevated arsenic levels are sharply restricted to the Bassac and Mekong River banks and 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 reductive dissolution of metal oxides. Regions exhibiting low and elevated arsenic levels are coincident with the present low relief topography featuring gently increasing elevation to the west and east of a shallow valley - understood as a relict of pre-Holocene topography.

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 the long term 1 in 10 persons with high concentrations of arsenic in their drinking water will die from 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 the lungs. And arsenic provides the first clear-cut evidence that early life exposure to an environmental toxin can result in marked increase in mortality in young adults from lung cancer.   Cancer is not the only long-term pulmonary outcome. In India subjects with arsenic-caused skin lesions have a 10-fold increased prevalence of bronchiectasis compared with subjects who did not have skin lesions (RR=10; 95% confidence interval 2.7–37). In Chile young adults aged 30-49 have a more than 40-fold increase in mortality from bronchiectasis if they had 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 marked increase in long term health risks which greatly exceed those from any other drinking water contaminant mean that all drinking water sources in the world should be tested for arsenic.

(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.uk,  manzurulh@gmail.com

This paper will address the problem of arsenic in groundwater in the context of debates about expertise and legal geographies. The case of Sutradhar v NERC, which was tested recently in the 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 an alleged ‘tort’ – a damage and a liability – resulting from a regime of environmental monitoring that did not pick up the presence of arsenic in groundwater. The House of Lords decided 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 Bangladesh where much foreign aid is devoted to understanding and mitigating its many environmental hazards. Although torts have a long history in Anglo-Saxon common law, there is little precedent for international litigation of this sort and new styles of legal argument are required.

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

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

Hugh Brammer, c/o Department of Geography, University of Cambridge, h.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 gradually accumulates in the topsoil, and amounts now appear to be reaching levels toxic to rice in some 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. Practical mitigation and 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; soil treatments to reduce arsenic uptake by crops; removing contaminated topsoils; and growing hyperaccumulator plant

(3) Monte Carlo Based Quantification of Increased arsenic-related cancer risk due to rice intake in West Bengal, India.
Ms Debapriya Mondal, Postgraduate Researcher, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, U.K.
debapriya.mondal@postgrad.manchester.ac.uk
Dr 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 in Bengal and other areas impacted by hazardous arsenic bearing groundwaters is currently in dispute. We use combined field, laboratory and computational methods to quantitatively estimate the overall increased cancer risk due to ingestion of arsenic-bearing rice in adults in two typical arsenic impacted districts in West Bengal. The distribution of chronic daily intakes (CDI) of arsenic in the study group has been estimated by Monte Carlo simulation following fitting of probability curves to measured distributions of arsenic concentration in rice, rice ingestion rates; and body weight. Estimated target cancer risks for an exposure duration of 10 years were then calculated using the USEPA (1989) one hit model. The mean increased life-time cancer risk, over and above that due to uptake of arsenic from drinking water, was 4.5 x 10^-4, higher than the 10^-4 to 10^-6 range typically used by the USEPA to guide determination of regulatory values. Furthermore, about 5% of the cancer risks calculated were greater than 10^-3. On-going work is focused on determining the nature of particular sub-groups of the population that may have significantly higher cancer risks than the mean.

Calatayud, M.,¹ Devesa, V.,¹ De Bovi-Mitre, G., ² Farias, S., ³ Gimenez, M. ⁴ Villaamil, E. ^5
1 Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Apdo 73, 46100 - Burjassot, Valencia, Spain. E-mail: vdevesa@iata.cis.es
² 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 Medio Ambiente, Av. Gral. Paz. 1499 (B1650KNA) San Martín, Provincia de Buenos Aires, Argentina.
⁴ Cátedra de Química Analítica. Facultad de Agroindustrias. Universidad Nacional del Nordeste, Argentina.
⁵ Cátedra de Toxicología y Química Legal. Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.

Argentina is one of the Latin American countries with the highest environmental arsenic concentrations. It has been estimated that over one million inhabitants, fundamentally in rural areas, depend on groundwater with arsenic concentrations in excess of 50 µg/L. One of the most affected areas is located on the Chaco-Pampean Plain, in the northern part of the country, where for over 20 years the population has shown symptoms of chronic endemic arsenicism. The present study evaluates human exposure to inorganic arsenic in populations of two provinces in the mentioned geographic setting: El Chaco and Santiago del Estero. An assessment has been made of the ingestion of inorganic arsenic through drinking water and raw and cooked foods in several families. The duplicate rations method has been used for food sampling. The results obtained - the first of their kind in Argentina - indicate ingestion far above the toxicological reference value recommended by the FAO/WHO (ISTP = 15 µg inorganic arsenic/kg body weight /week). This implies a serious public health problem in the region. Urgent implantation of the opportune palliative measures by the national authorities is thus required.
Acknowledgments: The authors are indebted to projects CYTED 105PI0272 and AECI A/4883/06 for the help received in conducting the present study.

Dr. Farhana Sultana Lecturer, King's College London

farhana@jonosc.com, farhana.sultana@kcl.ac.uk

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

SESSION 3 - Hydrochemistry and management of groundwater

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

The widespread problems posed by pollution of groundwater by arsenic require us to understand how arsenic gets into groundwater, moves through aquifers, and in some instances is 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, geothermal sources, or weathering of sulphide ores. Each mechanism has characteristic signatures allowing identification. Subsurface weathering of ores to give identifiable pollution in groundwater 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 and fate are much harder to determine. Additional mechanisms, such as competitive exchange of arsenic anions with other anions such as hydroxide, and weathering of silicates and trace sulphides may be important. The balance of influences will change along a flowpath to further complicate matters.   Reduction of iron oxide is a microbial process and the source of organic matter to drive the reaction is arguably the most important, and least known, part of the process. Competitive exchange is not biologically mediated, and has been studied much in the laboratory, but at arsenic concentrations that are far higher than those found in nature, so there is a problem with interpretation. Silicate weathering has been studied little. Such issues will be reviewed in this presentation.

Jiin-Shuh Jean Professor Department of Earth Sciences, National Cheng Kung University
Bibhash Nath Postdoctoral researcher Department of Earth Sciences, National Cheng Kung University
Li-O Weng Undergraduate student Department of Earth Sciences, National Cheng Kung University
Chia-Chuan Liu PhD student Department of Earth Sciences, National Cheng Kung University
Ying-Wen Yang PhD student Department of Earth Sciences, National Cheng Kung University

jiinshuh@mail.ncku.edu.tw

The adsorption/desorption of arsenic and its mineral species were investigated in the Blackfoot 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. The result 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 0.901 mg/L, and 0.062 to 6.22 mg/L, respectively). The arsenic speciation studies show that the reduced arsenic species (As-III) is widely distributed, with reduction ratio ranged from 57 to 99%, suggesting reducing nature of the BFD groundwater. The saturation indices computed by 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 isolated from 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 the adsorption is relatively low (29%) for 10 mg/L of initial arsenic.

Ondra Sracek¹, María Gabriela García^2
1 OPV s.r.o., Bĕlohorská 31, 169 00 Praha 6, Czech Republic
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 Chacopampean Plain (CPP). Two regions have been studied: Santiago del Estero in semiarid central CPP and more humid Tucumán at western limits of CPP. In both regions concentrations of dissolved As may reach values above 1,000 μg/l and high As concentrations are linked to shallow loessic sediments (upper 30 m of sedimentary sequence). There is a positive correlation between dissolved As and Na and HCO₃ concentrations. Also, there is positive correlation between As and several oxyanion-forming elements including V, F, B, and Mo present in volcanic ash in loessic sequence. Primary source of arsenic in ground water cannot be determined unequivocally, but highly weathered glass present in volcanic ash is a principal candidate. Contents of ferric iron extracted by the oxalic extraction step are low because there is 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 decreased by competition with other oxyanions for adsorption sites. Conditions in shallow aquifer are generally oxidizing and arsenic is present mostly as As(V). However, in the proximity of the Salí River in Tucumán As can be released as a consequence of the penetration of surface water contaminated by organic wastes and causing reductive dissolution of ferric mineral adsorbents in the neighboring aquifer. Similarly, high concentration of DOC with a potential impact on As mobilization were observed in the proximity of unlined irrigation canals at Santiago del Estero.

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

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

Mohammad Hoque PhD researcher UCL,   William Burgess Lecturer UCL,Matin Ahmed Professor Dhaka University
S. M. Ihtishamul Huq DPHE (Department of Public Health Engineering), Bangladesh
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 at ca. 150 m depth, occurs in places. This deep aquifer has been exploited sustainably to provide water supplies for individual towns – eg at Khulna where for over 20 years the aquitard has protected the deep aquifer from incursions of salinity and arsenic occuring in the shallow aquifer. Nevertheless, for a variety of alternative hydrogeological scenarios, exploratory models demonstrate the vulnerability of the deep aquifer to vertical leakage from the shallow system, limiting its potential to act as an ‘arsenic safe’ source of water. The lateral variability and regional extent of the aquitard is unknown, and many questions concerning the deep aquifer remain to be answered. We present empirical descriptions and preliminary conceptualisations of the deep aquifer environment from current research at individual sites across southern Bangladesh, incorporating: lithostratigraphy, sedimentology and hydrostratigraphy from geological and geophysical logs and head measurements, and profiles of groundwater chemistry, groundwater age and groundwater isotopic character for indications of groundwater flow. Uncertainties, and their implications for the viability of the deep aquifer as a source of arsenic-safe water, will be emphasised.

Dr. Ashok Ghosh, Prof.-in-Charge, Department of Environment and Water Management A.N.College [Magadh University], Patna, India ghosh51@hotmail.com
Prof. Shatrunjay K. Singh, Coordinator, Dept. of Environment and Water Management A.N.College [Magadh University], Patna, India
Dr. Nupur Bose, Lecturer, Dept. of Geography, A.N.College [Magadh University], Patna, India
Dr. 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 the Mid Ganga Plain, was to determine the existence and intensity of arsenic contamination in aquifers being tapped for direct and indirect ingestion of the properties of the region’s ground water, in the four districts of Bihar [India], i.e., Patna, Bhojpur, Vaishali and Bhagalpur. The methodology involved formulation of a protocol for arsenic detection in ground water, use of Field Test Kits for initial detection, obtaining GPS coordinates of arsenic hotspots for spatial analysis of the problem, and confirmatory testing of arsenic hot samples by U.V., and Atomic Absorption Spectrophotometry. Water samples of 28000 private and government owned hand pumps were tested. Many arsenic hotspots were detected in all the four districts, the coordinates of which were recorded by GPS. Arsenic contamination up to 1861 ppb. was found in the western district of Bhojpur, against the W.H.O. permissible limit of 10 ppb. The greatest frequency of contaminated hand pumps was noted in the eastern district of Bhagalpur. Sharp spatio-temporal variations of contamination levels were detected in this densely populated study belt.

 SESSION 4 - Mitigation and sustainability of water supply in Arsenic-affected areas

Dr Guy Howard, Policy Advisor, Department for International Development, g-howard@dfid.gov.uk
Dr Feroze Ahmed, Professor, Bangladesh Univeristy 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 National Policy for Arsenic Mitigation despite limited assessment of potential risk substitution. In 2004/5 a risk assessment was undertaken of a statistically representative sample of water supplies to estimate the disease burden, based on DALYs, associated with the four principal water technologies. Deep tubewells had the lowest disease burden and are the preferred technology from a public health perspective. Dug wells and pond sand filters showed elevated risks and require disinfection to meet acceptable levels of performance. Communities prefer deep tubewell technology and in practice they are the most commonly used. The findings illustrate that the stated preference in Government strategy documents should be revisited. The risk assessment also flagged the necessity of improving the currently inadequate knowledge of the quality of water resources in Bangladesh. The full extent of arsenic-safe deep aquifers and their recharge mechanism across Bangladesh remains unclear and available water 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

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

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

Our experience in West Bengal, India, where large numbers of people have been exposed to arsenic in tube-well water, is that interventions to provide arsenic-safe water in local communities require on-going surveillance and monitoring. Without continuing monitoring and education programs, people may revert to their previous sources of water with the new sources being underutilized, and in some cases becoming non-operational. Since 2001, Project Well has constructed modified dugwells in a pilot program to provide arsenic-safe water to small, community-groups in West Bengal. Over the last six years, we have designed and implemented a Follow-Up/Surveillance Program, to monitor and evaluate the utility of the dugwells. The Follow-Up program includes regular monitoring of the wells and interviews concerning the use of dugwell water that has enabled Project Well to assess causes of dugwell underutilization. Modifications that have been implemented include chlorination of the water to reduce bacterial contamination. Interview surveys discovered that consumption 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 with earthen filters. Dugwell water use has since increased. We conclude that all local small-scale community water interventions require ongoing monitoring.
Meera M Hira-Smith, Ph.D. (Geography),   Founder and Director,  Project Well, web site: http://www.projectwellusa.org/   Phone: (510) 530-6050
Researcher,   University of California, Berkeley, 140 Warren Hall,Berkeley, CA 94720-7360, Tel: 510/843-1736 / Fax: 510/843-5539
Web site at: http://socrates.berkeley.edu/~asrg/

Dr. Sudhanshu Sinha, Diptarup Kahali and M. Satyanarayana

Alarming level of arsenic in the groundwater of eight districts of West Bengal and 2 districts of Jharkhand in East India has become a serious health hazard. The number of people suffering from skin lesions, muscular disorder and even cancer, is constantly going up. This is an acute 'environmental health' problem since the rural population in these districts is solely dependent on groundwater for drinking, bathing and cooking.  The source of the problem is geological in origin, which has aggravated due to excessive withdrawal of groundwater for paddy cultivation in the wake of the green revolution of the 1970s. India-Canada Environment Facility (ICEF), a development organization supported by CIDA along with All India Institute of Hygiene and Public Health (AIIH&PH), a premier health institution of Government of India launched the first community-based arsenic mitigation project in July 1999 which ended in March 2007. ICEF's intervention has showcased 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 400 villages in Bengal, and 10 villages in Jharkhand. The project objective has been to empower the 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

George Adamson, University of Manchester
David 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, must explicitly 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 would result in a concurrent increase in diarrhoeal disease.  Our model, based upon that of Lokuge, suggests that mitigation simply involving the substitution of well water sources with As > 50 ppb would have a net positive impact on disease burden, as determined by Disability Life Adjusted Years (DALYs), but that the same mitigation for all the population exposed to well water arsenic as low as 10 ppb would, in contrast, have a negative impact. However, uncertainties in the dose-response relationship for arsenic uptake and the non-malignant high incidence conditions diabetes mellitus and ischemic heart disease means that the net impact on DALYs of such mitigation cannot be reliably 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.

Professor K M Ahmed Professor, University of Dhaka,   Dr Guy Howard Engineering Advisor DfID, Mr R Ogata Arsenic Mitigation Advisor JICA, Dhaka
S M Ihtishamul Huq Department of Public Health Engineering, Dhaka

The extent and severity of arsenic occurrence in Bangladesh is well-known. Although various initiatives have been taken since 1993, only a small proportion of the exposed population have access to a safe water option. Deep tube wells supply more than 90% of the safe water in arsenic affected areas; risk assessments and functionality surveys confirm that that this option has lowest risk, and is most sustainable.   The Department of Public Health Engineering (DPHE) has initiated the development of a national deep aquifer database with preliminary maps. Although hundreds of thousands of deep 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 deep aquifer. We shall critically review the concept of deep aquifer in Bangladesh; outline how the deep aquifer database was established; present preliminary deep aquifer maps; and discuss the major issues related to the sustainable management of the deep aquifer both for arsenic mitigation and as a vital natural resource for Bangladesh. We shall also highlight the existing policy and regulations regarding the deep aquifer and outline a management strategy to secure this strategic water resource for the future.

 SESSION 5: SHORT CONTRIBUTIONS AND DISCUSSION

Bibhash Nath Postdoctoral Researcher Department of Earth Sciences, National Cheng Kung University, Taiwan
Debashis Chatterjee Associate Professor Department of Chemistry, Kalyani University, India
Jiin-Shuh Jean Professor Department of Earth Sciences, National Cheng Kung University, Taiwan
Prosun Bhattacharya Associate Professor Department of Land and Water Resources Engineering, Royal Institute of Technology, Sweden
Kazi Matin Ahmed Professor Department of Geology, University of Dhaka, Dhaka 1000, Bangladesh  bibhash12@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. The major pathway of high arsenic (As) concentration in groundwater is the reductive dissolution of the "As-traps" (mostly sedimentary iron-oxides and hydroxides) under local reducing condition. The high As aquifers are largely in the low land areas intersparsed with low arsenic zones. The release of redox sensitive species (As, Fe, Mn) is the function of bioavailable forms of iron oxide, concentration as well as distribution of organic matter and availability of electron donors in the alluvium. Aqueous speciation indicate that the ratio of As(III)/(V) is varying 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 chemical partitioning. The concentration and distribution of siderite/vivianite is also important in explaining large-scale and variable aqueous As species in groundwater. Solid phase chemical partitioning shows that the arsenic is associated with amorphous Fe-oxide together with surface bound PO43- in coarser sediments and is playing an important role in As mobilization

(2) VULNERABILITY OF POPULATION EXPOSED TO ARSENIC CONTAMINATION IN THE MID GANGA PLAIN OF BIHAR, INDIA

Dr. Ashok Kumar Ghosh, Prof.-in-Charge, Dept. of Environment and Water Management A.N.College, Patna nupur.bose@gmail.com
Dr. Nupur Bose, Lecturer, Dept. of Geography, A.N.College, Patna, India
Dr. Narendra Kumar Roy, Resource Person, Dept. of Environment and Water Management A.N.College, Patna, Bihar
Dr. Ajay Upadhyay, Resource Person, Dept. of Environment and Water Management A.N.College, Patna, India
Mr. Amardeep Singh, Research Scholar, Dept. of Environment and Water Management A.N.College, Patna, India
Mr. 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, have severe health implications among the rural population in the state on Bihar, India. This study covered a 10 km. belt along the Ganga river in the four districts of Bhojpur, Patna, Vaishali and Bhagalpur. The purpose of this research was to obtain the distribution and quantum of human population at risk of arsenic poisoning and population composition characteristics of the arsenic-affected belt. The methodology adopted was based upon self-generated and confirmed primary data on abnormally high arsenic concentration in ground water ranging from 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 obtain estimates of affected population, while Topographical and Administrative Block Maps of all four districts were referred to for studying the spatial pattern of this population. The result showed that approximately 1,537,426 persons [about 47% of the population] residing in the study belt are at risk. In Bhagalpur study belt, the vulnerability extends to more than 75% of the population. Symptoms of arsenic poisoning are widespread, especially among child population. Appropriate mitigation strategies are yet to be undertaken in this study area.

Atanu Sarkar, Department of Policy Studies, TERI University, The Energy and Resources Institute, India Habitat Centre, Lodhi Road, New Delhi 110003, India

Arsenic contamination of groundwater has emerged as a major environmental health problem in India. Since the discovery of first arsenicosis case in 1982, significant progress in research has been witnessed in various disciplines. But, current mitigation strategy has essentially taken segmental approach without considering holistic view. Hence, the suffering of the people 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 case studies, generated from various researches along with field-survey based data conducted in two affected districts in India. It also develops evidence-based alternative concept with interdisciplinary characteristics by forming a better matrix, which is expecting to have policy relevance in changing socio-political landscape. Data analysis shows that there is a need of integration of current arsenic related issues, including population health and vulnerability (class, caste and gender based disparity), socio-economic impact, social resilience, natural resource management, appropriate technology (water purification) in local context, ecological damage (soil, crop, livestock), agro-trade policy and practice, institutions and participatory governance.  The strategy should begin with identification of stakeholders (including community) who would undergo more rigorous social learning to design, implement and sustain integrated, polycentric, horizontal and adaptive approach.

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

H. Zhang, 

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

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. Odediran^8
1Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
²Queens College, City University of New York, Flushing, NY 11367, USA
³The Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang 150081, P.R.China.
⁴Department of Environmental and Occupational Health, College of Public Health, China Medical University, Shenyang, Liaoning, PR China
⁵ Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, Shanxi 041000, China
⁶Department of Toxicology, School of Public Health, Guiyang Medical University, Guizhou, 550004, PR China
⁷Guizhou Center for Disease Control and Prevention, 73 Bageyan Road, Guiyang 550004, Guizhou, China
⁸UNICEF, Water and Environment, New York, USA

China has well-documented As endemics areas with high occurrence rates of arsenicosis possibly due to longer histories of exposure and biomedical investigations dating back to the1980s. Recently, five articles that report the health effects of As in the exposed population and describe the mitigation approach 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 various degrees of skin lesions were identified. This arsenicosis occurrence rate of 7.5% is likely an overestimate 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 the percentage of wells containing > 50 mg/L of As (R² = 0.70). For example, if a province had on average 10% of wells containing > 50 mg/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 that children had a higher percentage of dimethylarsenic acid (DMA) than adults. In Shanxi, an ecological study of 720 children between 8 to 12 years of age showed that IQ scores decreased from 105 ± 15 for 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 mg level of As originated from coal-fired stoves showed that long-term As exposure may be associated with damage of chromosomes and DNA, gene mutations, gene deletions, and alterations of DNA synthesis and repair ability. Fortunately, health education to that population has resulted in dramatic decrease 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 to illustrate the heterogeneous nature of As distribution in the crust and to shed light on the tectonic environment that lead to anomalies of As concentrations in source rock. Further geochemical investigations are much needed to understand the heterogeneity of As distribution in the crust, and its significance on occurrence of elevated groundwater As in sedimentary aquifers. However, the systematic geographic distribution of As-rich minerals in Au deposits along the orogeny belts was suggestive that As anomalies in whole rock may be more wide spread, the geographic extent of such As anomalies in whole rock remain to be defined by more whole rock analyses. The distribution of As in soil from on-going high density sampling in China can be used to identify promising areas for whole rock analyses. An intriguing prediction of the conceptual model of As distribution in the crust is that rifting and pull apart sedimentary basins in China are more prone to have groundwater As problems if they are down gradient from high As source rocks. 

(6) "Mass Arsenic Poisoning of Rural Bangladesh - Health impact and Community based mitigation of patient management and Safe Drinking water, DCH Experience."

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 other serious health, social and environmental problem from arsenic poisoning.    In June 1996, Dhaka Community Hospital detected arsenic Patient in Paksey, Pabna district and pioneered the detection of Arsenic Contamination of drinking water and Arsenic health effects in rural Bangladesh. Dhaka Community Hospital conducted a limited field survey with School of Environment Studies (SOES) of Jadavpur University, India and published its findings in a National conference in January 1997 and established the evidence of mass arsenic poisoning of rural Bangladesh. Since then DCH conducted survey all over Bangladesh with various national, International and UN agencies and organised 6 international conferences. DCH was instrumental in mobilizing national and international interest and activities to counter these devastating health and environmental hazard facing millions of people in South and South-East Asia.  Pathophysiology of "Arsenicosis", the term coined to define the disease manifested by chronic arsenic poisoning and its complications are still not clear to the medical profession. Researches have been 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 of Patient management and Safe Drinking water in rural Bangladesh. This programme is being reflected in National Arsenic Mitigation Policy and Action Plan and various organizations has taken up this model of Arsenic mitigation programme and are being implemented.

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

Groundwater (drinking water) samples were collected from 4 neighborhoods in western Bangladesh (Bualda, Fulbaria, Jamjami, Komlapur). To the extent possible, the sampled tubewells in each neighborhood were distributed at 500-meter intervals along perpendicular axes that radiated in 4 equal lengths from the center. Each neighborhood had 17 sampling locations: 4 north, 4 east, 4 south, 4 west, and 1 in the center. Each sample was analyzed for arsenic (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 drinking water 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 and interviews were used to determine the effects of geologic deposits, depth of tubewell, age of tubewell, and number of users per tubewell on the concentrations of these 14 elements in this groundwater.

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

Recent studies in populations chronically exposed to inorganic arsenic have revealed a correlation between the urinary arsenical species resulting from inorganic arsenic metabolism (AsIII, MMAIII, DMAIII, AsV, MMAV and DMAV) and the development of certain diseases associated with exposure to the toxic agent. This urinary profile could be used as a biological marker of chronic arsenicism. The principal problem in determining these urinary metabolites is 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 poor overland communications. Consequently, the development of a technique allowing the in situ stabilization of these trivalent forms would be very interesting. The present study develops a method for stabilizing arsenical metabolites, with their posterior separation and assay. Preservation of the trivalent arsenical species is based on the use of a complexing substance, diethylammonium diethyldithiocarbamate (DDDC). The DDDC-trivalent species complex remains stable at room temperature for as long as required for sample transport. Selective extraction is carried out with carbon tetrachloride and sodium hydroxide. The arsenical species are determined by HPLC coupled to atomic fluorescence spectroscopy.

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