NDLI: Arsenic in groundwater of the Bengal Basin, Bangladesh: Distribution, field relations, and hydrogeological setting

Content Provider	Springer Nature Link
Author	Ravenscroft, Peter Burgess, William G. Ahmed, Kazi Matin Burren, Melanie Perrin, Jerome
Copyright Year	2004
Abstract	Arsenic contaminates groundwater across much of southern, central and eastern Bangladesh. Groundwater from the Holocene alluvium of the Ganges, Brahmaputra and Meghna Rivers locally exceeds 200 times the World Health Organisation (WHO) guideline value for drinking water of 10 µg/l of arsenic. Approximately 25% of wells in Bangladesh exceed the national standard of 50 µg/l, affecting at least 25 million people. Arsenic has entered the groundwater by reductive dissolution of ferric oxyhydroxides, to which arsenic was adsorbed during fluvial transport. Depth profiles of arsenic in pumped groundwater, porewater, and aquifer sediments show consistent trends. Elevated concentrations are associated with fine-sands and organic-rich sediments. Concentrations are low near the water table, rise to a maximum typically 20–40 m below ground, and fall to very low levels between about 100 and 200 m. Arsenic occurs mainly in groundwater of the valley-fill sequence deposited during the Holocene marine transgression. Groundwater from Pleistocene and older aquifers is largely free of arsenic. Arsenic concentrations in many shallow hand-tube wells are likely to increase over a period of years, and regular monitoring will be essential. Aquifers at more than 200 m below the floodplains offer good prospects for long-term arsenic-free water supplies, but may be limited by the threats of saline intrusion and downward leakage of arsenic.L’arsenic contamine les eaux souterraines dans la plus grande partie du sud, du centre et de l’est du Bangladesh. Les eaux des nappes alluviales holocènes du Gange, du Brahmapoutre et de la Meghna dépassent localement 200 fois la valeur guide donnée par l’OMS pour l’eau de boisson, fixée à 10 µg/l d’arsenic. Environ 25% des puits du Bangladesh dépassent la valeur standard nationale de 50 µg/l, affectant au moins 25 millions de personnes. L’arsenic a été introduit dans les nappes par la dissolution par réduction d’oxy-hydroxydes ferriques sur lesquels l’arsenic était adsorbé au cours du transport fluvial. Des profils verticaux d’arsenic dans l’eau souterraine pompée, dans l’eau porale et dans les sédiments des aquifères montrent des tendances convergentes. Les concentrations élevées sont associées à des sédiments à sable fin et riches en matières organiques. Les concentrations sont faibles au voisinage de la surface de la nappe, atteignent un maximum typiquement entre 20 et 40 m sous le sol, puis tombent à des niveaux très bas entre 100 et 200 m. L’arsenic est surtout présent dans les eaux souterraines de la séquence de remplissage de vallée déposée au cours de la transgression marine holocène. Les eaux souterraines des aquifères pléistocènes et plus anciens sont très largement dépourvus d’arsenic. Les concentrations en arsenic dans de nombreux puits creusés à la main doivent probablement augmenter au cours des prochaines années ; aussi un suivi régulier est essentiel. Les aquifères à plus de 200 m sous les plaines alluviales offrent de bonnes perspectives pour des alimentations en eau sans arsenic à long terme, mais ils peuvent être limités par les risques d’intrusion saline et la drainance descendante de l’arsenic.El arsénico ha contaminado gran parte de las aguas subterráneas en el Sur, centro y Este de Bangla Desh. Su concentración en las aguas subterráneas del aluvial Holoceno de los ríos Ganges, Brahmaputra y Meghna supera localmente en un factor 200 el valor guía del arsénico en el agua potable, establecido por la Organización Mundial de la Salud (OMS) en 10 µg/L. Aproximadamente, el 25% de los pozos de Bangla Desh superan el estándar nacional de 50 µg/L, afectando al menos a 25 millones de personas. El arsénico ha llegado a las aguas subterráneas por la disolución reductora de hidróxidos férricos a los que se adsorbe durante el transporte fluvial. Los perfiles del arsénico en las aguas subterráneas bombeadas, agua de poro y sedimentos del acuífero muestran tendencias coherentes. Las concentraciones elevadas están asociadas a arenas finas y sedimentos ricos en materia orgánica. Las concentraciones de arsénico son bajas cerca del nivel freático, se incrementan hasta un máximo que se localiza generalmente a entre 20 y 40 m bajo la cota del terreno, y disminuyen a valores muy pequeños entre alrededor de 100 y 200 m. El arsénico se encuentra sobretodo en las aguas subterráneas existentes en la secuencia de sedimentación que tuvo lugar en el valle durante la transgresión marina del Holoceno. Las aguas subterráneas del Pleistoceno y acuíferos más antiguos están mayoritariamente libres de arsénico. Es probable que las concentraciones de arsénico aumenten en los próximos años en muchos pozos de tipo tubo perforados manualmente, por lo que será esencial efectuar un muestreo regular. Los acuíferos ubicados a más de 200 m bajo las llanuras de inundación ofrecen buenas perspectivas de abastecimiento a largo plazo sin problemas de arsénico, pero pueden estar limitados por las amenazas de la intrusión salina y de la precolación de arsénico desde niveles superiores.
Starting Page	727
Ending Page	751
Page Count	25
File Format	PDF
ISSN	14312174
Journal	Hydrogeology Journal
Volume Number	13
Issue Number	5-6
e-ISSN	14350157
Language	English
Publisher	Springer-Verlag
Publisher Date	2004-03-09
Publisher Institution	International Association of Hydrogeologists
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Arsenic Bangladesh Contamination General hydrogeology Hydrochemistry
Content Type	Text
Resource Type	Article
Subject	Earth and Planetary Sciences Water Science and Technology

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Regional hydrostratigraphy and groundwater flow modeling in the arsenic-affected areas of the western Bengal basin, West Bengal, India

Sources of low-arsenic groundwater in the Bengal Basin: investigating the influence of the last glacial maximum palaeosol using a 115-km traverse across Bangladesh

Arsenic in shallow groundwater of Bangladesh: investigations from three different physiographic settings

Influence of hydrostratigraphy and structural setting on the arsenic occurrence in groundwater of the Cimino-Vico volcanic area (central Italy)

Controls on groundwater flow in the Bengal Basin of India and Bangladesh: regional modeling analysis

Arsenic contamination of groundwater: Mitigation strategies and policies

Mega-scale groundwater quality challenges and the need for an inter-disciplinary approach

Investigating cross-contamination of aquifers

Hydrogeology of the Kabul Basin (Afghanistan), part II: groundwater geochemistry

Arsenic in groundwater of the Bengal Basin, Bangladesh: Distribution, field relations, and hydrogeological setting

Similar Documents

Regional hydrostratigraphy and groundwater flow modeling in the arsenic-affected areas of the western Bengal basin, West Bengal, India

Sources of low-arsenic groundwater in the Bengal Basin: investigating the influence of the last glacial maximum palaeosol using a 115-km traverse across Bangladesh

Arsenic in shallow groundwater of Bangladesh: investigations from three different physiographic settings

Influence of hydrostratigraphy and structural setting on the arsenic occurrence in groundwater of the Cimino-Vico volcanic area (central Italy)

Controls on groundwater flow in the Bengal Basin of India and Bangladesh: regional modeling analysis

Arsenic contamination of groundwater: Mitigation strategies and policies

Mega-scale groundwater quality challenges and the need for an inter-disciplinary approach

Investigating cross-contamination of aquifers

Hydrogeology of the Kabul Basin (Afghanistan), part II: groundwater geochemistry

Arsenic in groundwater of the Bengal Basin, Bangladesh: Distribution, field relations, and hydrogeological setting