Arsenic in Bihar

Annual Conference 2007, Royal Geographical Society, London Session key: BSG-session 3
29-31 August, 2007 Paper-5



Arsenic contaminated aquifers: a study of the Ganga levee zones in Bihar, India


A.K.Ghosh1. S.K..Singh2, Nupur Bose3, S. Chaudhary4
1 Department of Environment and Water Management, A.N.College, Patna
2 Department of Environment and Water Management, A.N.College, Patna
3 Department of Geography, A.N.College, Patna, India
4 Department of Botany, T.M.Bhagalpur University, Bhgalpur, India



ABSTRACT-
'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.


Introduction

Arsenic is one of the less abundant metalloids forming the earth’s crust. Its important physico-chemical characteristic is that it is commonly concentrated in sulphide-bearing mineral deposits, pyrites and hydrous iron oxides1,2. Its presence in ground water sources is attributed to a number of natural and anthropogenic causes, based on its property of solubilizing in ground waters “depending on pH, redox conditions, and temperature and solution composition”3. Main sources of arsenic in aquifers include organic carbon or black shales, Holocene alluvial deposits, and volcanic sources4. Of particular relevance to this study, is the “strongly reducing, arsenic-rich aquifers”5 of the young alluvial sediments of the Mid Ganga Plains. Arsenic occurs widely in aquifers of deltaic sediments6, near zones of orogeny, and in deep sandy aquifer layers7 as fluvial deposits. It is introduced into the aquifer sediments in soluble state and gets adsorbed on iron-rich clastic grains and authigenic siderite concentrations. The adsorption process and its consequent desorption are stated to be controlled by microbial activity within the concerned aquifers8. Sediments containing 1 to 20 ppb. of arsenic can give rise to high dissolved arsenic of >50 ppb. by one or both of two possible causes – an increase of pH of over 8.5 or the onset of reductive iron dissolution3. Also, presence of solutes can also decrease or prevent the adsorbtion of arsenate and arsenite ions onto fine grained clays, like iron oxides8. Additional processes promoting high arsenic content in ground water are oxidation and dissolution of arsenian pyrite, Fe[As,S]2, and arsenopyrite [HN8], FeAsS9. Oxidation occurs either by infiltration of oxygenated ground waters10, or by lowering of ground water table into a stratigraphic zone of arsenic –rich sulphides11.

There are two main theories as to how arsenic is released into the groundwater -
Pyrite oxidation: In response to pumping, air or water with dissolved oxygen penetrates into the ground, leading to decomposition of the sulphide minerals and release of arsenic.
Oxyhydroxide reduction: Arsenic was naturally transported in the river systems of Bangladesh adsorbed onto fine-grained iron or manganese oxyhydroxides. These were deposited in flood plains and buried in the sedimentary column. Due to the strongly reducing conditions which developed in the sediments and groundwater of certain parts of Bangladesh the arsenic was released into groundwater. The release mechanism is still hotly debated but the second theory is thought to be the more likely explanation.

Our recent hydrochemical study of groundwater arsenic along transects from the foothill alluvium to the Indian Shield exposed in Mid Ganga Basin indicate that As concentrations are much higher in groundwater collected from the youngest alluvial terraces (~50% samples have 0.01 mg/L [WHO Maximum Contaminant Level] As, maximum 0.52 mg/L), than those associated with the shield (all  0.005 mg/L). Most (87%) of the As is present as As(III) 12.

Arsenic toxicity
Arsenic is highly toxic carcinogen (Category I) and also a mutagen / teratogen (harming foetus). Arsenic in ground water that is used for human consumption water, poses the greatest threat to public health13. Reliable data on exposure and health effects are rarely available, but it is clear that there are many countries in the world where arsenic in drinking water has been detected at concentrations greater than the WHO Guideline Value, 0.01 mg/L or the prevailing national standards. These include Argentina, Australia, Bangladesh, Chile, China, Hungary, Mexico, Peru, the United States of America and some countries in the South-East Asia Region. The arsenic crisis in Bangladesh has been described as one of the worst cases of mass poisoning in world history. Studies from West Bengal in India show that approximately 5 million persons are consuming groundwater containing arsenic exceeding 0.05 mg/L. Recent unconfirmed reports point to the presence of arsenic in Tamil Nadu and other states of India, implying industrial contamination of groundwater. In India, it is estimated that 220 000 of the 5 million exposed subjects are showing signs of arsenicosis.
W.H.O.14 has published Guidelines for Drinking Water Quality in which a contemporary value for an acceptable maximum level of Arsenic was set at 10 ug/l/ for safe water. National standards range from 7 ug/l in Australia to 50 ug/l in Vietnam, Cambodia and Bangladesh15.
Long-term oral exposure via drinking water can cause cancer of the skin16, lungs, urinary bladder, and kidneys. With long term exposure the first changes are usually seen in the skin pigments (indicator of arsenic poisoning), then hyperkeratosis. Symptoms of chronic arsenic poisoning can take five to 15 years to appear and are apparently influenced by nutrition and general health standards24. Increased risks of lung and bladder cancer and of skin lesions have been observed at arsenic concentrations of less than 0.05 mg / L of drinking water..

Statement of the problem-
Naturally occurring Arsenic, as a water quality issue in South Asia, began to attract international attention in the early decade of the nineties, when widespread chronic arsenic poisoning cases became apparent in Bangladesh and later in West Bengal, India17,18. Arsenic pollution in groundwater in this part of the subcontinent is a contentious issue. Investigations into the causation of arsenic pollution require a multidisciplinary approach19.

Later, the discovery of arseniferrous aquifers in Simaria-Ojhapatti village under Shahpur Block in Bhojpur, Bihar, located further upstream of the Bengal basin in 2003, raised apprehensions about the greater spatial spread of this dreaded contamination along the Ganga Valley.
In 2002, School of Environmental Studies, Jadavpur University, detected arsenic levels higher than the Bengal contamination readings. This has made it urgent for further detection of Arsenic infestation in the surrounding aquifers near River Ganga, within Bihar20,21. The study area of this research incorporates Patna District, the justification being its close proximity to Bhojpur District. The two districts are separated by the River Sone which confluences with the Ganga on the northern boundaries of both Bhojpur and Patna. Based on the hypothesis of previous random water analysis about possibilities of contamination in newer fluvial deposits,22, the study area of levee region was confined to an approximate belt of 10 kms. along the southern bank of River Ganga in the districts of Patna, Bhojpur and Bhagalpur; and along the northern bank in Vaishali district,

Methodology-
This research team formulated the Protocol, duly approved by Govt. of Bihar, Govt. of U.P., and UNICEF, for detection of arsenic over large areas. This Protocol is specifically intended for use by all those involved with arsenic detection in hand pumps using field test kits. The methodology incorporated in the Protocol has the following five significant components-
· All the public hand pumps of the study area were tested for Arsenic content through Field Test Kits by trained Staff.
· Each public hand pump tested was marked, with a unique Identification Code at the time of testing. The 13-digit code was derived from the Census 2001. This information identified the State, District, block and village, and finally the serial number of the Hand pump.
· Bihar Plains consist of sandy soils, where recent research has shown that presence of silica often masks the signal of arsenic from many chemicals11, thereby “creating a false optimum” of arsenic content lower than actually existing. Hence, 10% random verification of field test kit results was done through Atomic Absorption Spectroscopy.
· All field test results above 40mg/l were retested using AAS / UV Spectrophotometer23.
· Marking of hand pumps were done to inform the public of their status (safe/unsafe). The color codes applied were – Blue for FTK readings below 40 ppb.; yellow for FTK readings 40- 79 ppb.; and, Red for FTK readings of 80 ppb. and above.
· There is an increasing need to map the level of arsenic concentration, trends of arsenic flow and temporal changes occurring in its concentration levels. Recording the locations of Arsenic-affected hand pumps, using Global Positioning System (GPS) units24, was done, followed by mapping of the arsenic occurrences. The other references used were Block Maps, Topographical Maps.
· Use of field test kits as basic indicator of arsenic contamination -
The initial assessment of ground water arsenic contamination has been done by Field Test Kits designed by National Chemical Laboratory [NCL], Pune,and manufactured by Chem In corporation,Pune. As a reliable testing tool, FTK usage was previously discarded. However, during the Patna Study, the efficacy of FTK was proved by statistical comparison with AAS test results of the same water samples, in Sriram Institute of Industrial Research [SIIR], New Delhi. The SIIR Report on the efficacy of FTK has proved that it is a fast and economical, general indicator of arsenic contamination in water, provided the FTK users are trained technicians with a good idea of laboratory procedures.

F.T.K. Results -
Of the total of 27061 public hand pumps surveyed and sampled by Field Test Kits till date, 5757 hand pumps were contaminated with arsenic of over 10 ppb.. Taking into account the permissible limit of 10 ppb. set by W. H. O, the table below reveals massive contamination in Maner, Danapur, Bakhtiarpur, and Barh blocks [ Patna district]; Barhara and Shahpur blocks [Bhojpur district]; Kahalgaon, Pirpainti and Nathnagar blocks [Bhagalpur district]; and, Raghopur, Hajipur and Sahdai Buzurg[ Vaishali district].. These arsenic hotspots, forming the first group, have been found to be highly concentrated in the DIARA region. It would be not out of place to mention that there seems to be certain continuity in the occurrence of ground water arsenic, from Bhojpur district in the west into Bhgalpur to the east.
However deviations in the contiguity of the arsenic belt was noted in Sampatchak Block in Patna District and in Barhara and Shahpur blocks in Bhojour. Widespread occurrences of low level contaminations of around 50 ppb. in Sampatchak block, 5 km. away from the southern river bank,
In Patna, a fair presence of arsenic above 10 ppb., include Mokama, Sampatchak, Patna, Fatuha and Phulwari. The general areal extent of this contamination is in close proximity to the right bank of river Ganga, except in Sampatchak, where lower arsenic concentrations of 50 ppb. and less were spread over the entire block. While most of the blocks had a considerable number of “safe” or BDL marked hand pumps, the same is of limited proportion in Maner, where largest number of contaminated hand pumps were identified. Except Bihta, Naubatpur, Ghoswari and Daniawan all the blocks had contamination levels of above 10 ppb. to 50 ppb.

FTK Readings of water samples in worst
affected blocks,
Patna District
Sl.
No.
Name of
The Block
11 ppb. and above
1
Maner
38.04%
2
Danapur
26.87%
3
Sampatchak
16.58%
4
Barh
10.60%
5
Bakhtiarpur
14.47%

In Bhojpur, of the 5917 FTK tested samples, arsenic contamination at various levels, have been noted in 2806 samples. Udwantnagar has 100 contaminated sources against 67 “Nil” hand pumps. Barhara, Shahpur and Bihia have the maximium numbers of contaminated samples. The intensity of arsenic content can be best gauged by the. Fact thar Barhara , Shahapur and Bihia collectively spews arsenic rich water [> 50 ppb] from 1381 public hand pumps. Except Ara and Koilwar, the remaining 4 blocks have the largest share of arsenic contamination sources in the >50 ppb class. Conversely, Ara and Koilwar have the largest proportion of arsenic–free hand pumps. The total percentage of arsenic contaminated water samples fall within 3 groups- high contamination of over 50 % [Barhara and Udwantnagar]; moderate contamination of 30% to 50 % [Shahpur and Behea]; and low contaminated occurrences of below 30 % [Ara and Koilwar].
Overall, level of arsenic contamination in public hand pumps is both higher and more widespread than the situation in the neighboring Patna District

FTK Readings of water samples in worst
affected blocks,
Vaishali District
Sl.
No.
Name of the Block
11 ppb. and above
1
Raghopur
17.18
2
Hajipur
55.58
3
Bidupur
71.19
4
Sahdai Buzurg
68.09
5
Desri
68.42










In Vaishali, a total of 8080 water samples were tested by F.T.K.s, of which 18.73% were found to be contaminated. Raghopur was the only block that had 100% contaminated samples, although in comparison to other blocks, a large chunk of contaminated samples fell in the “below 40 ppb.” group. In Hajipur, 61.69% source samples tested arsenic – free, and only 119 [7.57%] of contaminated samples were of 40 ppb. and more. Bidupur, with 81.58% uncontaminated samples, had the largest share of arsenic “NIL” water source. But, a total of 102 [28.81% of contaminated samples] were in the 40 ppb+ range, making this block the most contaminated one. Sahdai Buzurg and Desri had 66.88% and 74.93% uncontaminated samples respectively.

FTK Readings of water samples in worst
affected blocks,
Bhojpur District
Sl.
No.
Name of the Block
11 ppb. and above
1
Barhara
55.35%
2
Shahpur
37.97%
3
Bihia
33.37%
4
Udwant-
Nagar
55.69%
5
Ara
15.23%
6
Koilwar
26.12%













In Bhagalpur District , 8075 hand pumps were subject to FTK tests, of which over 2500 sources tested positive. Kahalgaon and Pirpainti, had the largest number of contaminated drinking water hand pumps, followed by Nathnagar, Sabour and Sultanganj blocks.









FTK Readings of water samples in worst
affected blocks,
Bhagalpur District


Sl.
No.
Name of the Block
11 ppb. and above .*
1
Kahalgaon
48.50 %
2
Pirpainti
43.00%
3
Sabour
31%
4
Nathnagar
11.00%
5
Sultanganj








ANALYSIS OF AAS AND UV SPECTROPHOTOMETER RESULTS-
Out of 6101 samples collected in Patna, 457 samples were retested by AAS-HG method at Sriram Institute of Industrial Research, New Delhi. Of the 457 samples tested there, 390 samples were confirmed to have Arsenic content of over 10 ppb. Samples have tested as having more than 50 ppb. As. content. The highest As. content detected by AAS Method is 724 ppb. , this sample being collected from Naikatola Village, Maner block, in the hand pump located near the house of Mr. Pundev Singh.
In Danapur block the highest As. Level detected by AAS method is 450 ppb. at Kasimchak, from the hand pump located near the house of Mr. Sitaram Rai. The next highest reading of 409 ppb.in this block, is from the hand pump near the house of Mr. Laxman Rai of Harshamchak village, Danapur block.
In Bakhtiarpur, the highest arsenic level detected by AAS method is 553 ppb. in Ghiaspur Mahazi, outside the house of Ashok Mahto, followed by 538 ppb. in Kala Diara, outside the house of Faudar Paswan. In Barh, the highest arsenic level read by AAS is 484 ppb. in Malahi Banda, near the house of Balaj Mahto; and 441ppb. near the house of Mohan Mahto
In Bhojpur, 27.35% of the AAS-tested 457 samples fall within the 50-99 ppb. group, and 25.38% have arsenic content of between 11-49 ppb. Table-3 reveals a tapering down of the number of samples in the successive higher arsenic value groups. Uncontaminated samples were only 10.5%, while another 4.6%samples were within the permissible limit of below 10 ppb. All the four critical l blocks had large numbers of contaminations between 11-99 ppb.
The first list of AAS tested water samples from 656 villages in Barhara and Shahpur Blocks have been obtained. All the villages in this list have hand pumps with more than 10 ppb. Arsenic Content, interspersed with a lesser number of safe hand pumps [Table -15].
In the total of 656 AAS tested samples received till date, the highest values of 1861 and 1064 has been recorded in the houses of Krishna Pandey and Munna Pandey respectively, in village Pandey Tola, Sinha in Barhara. In Shahpur, the highest arsenic contamination of 598 ppb was recorded in the house of Baban Prasad at village Karnamepur.
90.05% the 586 contaminated samples are in the 11ppb. – 500ppb. level. Barhara has 91.07% and Shahpur has 88.75% in this contamination group. The two values of over 1000 ppb. merit serious attention to the Arsenic contamination problem in Barhara.
In Vaishali district, Highest number of contaminated samples was found in the 51-100 ppb. group [142 or 54.44%]. Another 77 FTK samples [28.51%] fell in the 11-50 ppb. group, while 36 samples [13.33%] were of 101-150 ppb. contamination levels. The remaining 15 samples tested more than 151 ppb.UV results of Bidupur show the largest contaminated samples in the 51-100 ppb. group among all the contamination groups of all the blocks. Desri’s water samples ranged between 11-101 – making it the least contaminated of the blocks surveyed
In Bhagalpur








SUMMARY OF AAS/UV SPECTROPHOTOMETER RESULTS
DISTRICT

No. of water sources with
more than
10 ppb. arsenic
Highest reading
Patna

392
724ppb
Bhojpur

656
1861 ppb.
Vaishali

270
360 ppb
Bhagalpur

1402
608 ppb.


Mapping of Arsenic Hotspots in Bihar -
GPS coordinates were obtained for all the hotspots. These were then imposed on the topographical sheets and the spatial parameter was assessed.
A total of 171 villages were surveyed in Patna.. Every block has some degree of arsenic contamination, Maner having more than 40 % of the water samples, and Danapur and Sampatchak with 30-40% of the samples testing positive. Less than 10 % of the samples from only Patna block tested positive. The remaining blocks had varying percentage values in the intermediate range between the two extremes. Sampatchak was the single block with diffuse spread of arsenic contaminated hand pumps - low intensity arsenic contamination exist in almost every village, and the highest reading went upto 50 ppb.
3 Clusters of hotspots were noted – Maner cluster, Danapur Cluster, Bakhtiarpur Cluster and Barh Cluster. All these hotspots were located in the DIARA or floodplains that are subject to annual inundation. Mokama and Pandarak had frequent occurrences of 50 ppb. too. Gradual decreases in the number of highest readings were noted from west to east. Also, arsenic concentrations tapered down towards south, supporting the hypothesis of arsenopyrite oxidation of Holocene sedimentary deposits3, 10. This oxidation has been attributed to excessive withdrawal of ground water by the inhabitants, both for domestic purpose and agricultural use.As one moved away from the riverbank, the frequency of arsenic contaminated sources decreased. Tests were also extended southward along the right bank of river Sone in order to seek spread of contamination. However, all the samples collected from the Sone bank further south of its confluence with the Ganga, tested negative. It can be safely concluded that the menace of Arsenic in ground water exists in Patna district, parallel to the Ganga riverbank, in a broken belt from Maner in the west to Mokama in the east. These findings need further regular monitoring to detect future changes in its extent and intensity.
As per AAS confirmatory test results, Arsenic contaminated sources were found to be greatest in Maner and Danapur blocks and were interpretated through isoline mapping of northwest Patna. The map obtained thus, revealed four concentrations of high arsenic levels, around which decreasing iso-values were interpolated. The resultant pattern is highly indicative of the presence of arsenic rich rock layer within or very close to the major aquifer [[major aquifer depth- 60 to 110 feet] in this area, from where maximum water is withdrawn. This finding needs to be further assessed by possible digging of boreholes, for geochemical analysis, in the peak value spots identified in the map. The space between the Maner and Danapur Clusters are uninhabited, but it falls within the zone of potential arseniferrous aquifers. The peculiarity of this metalloid in Patna is that it is non-existent in open wells, and is absent on, and, beyond the older alluvium of the southern levee.
Choropleth maps were prepared on the basis of FTK data to identify the arsenic hotspots in Bhojpur District. GPS readings were obtained from all the known arsenic affected villages. Barhar and Shahpur blocks had the highest frequency of arsenic contaminated handpumps in almost all the villages.. Behea is contaminated in its north-easterm parts, while Udwantnagar is heavily contaminated in the small area covered. Ara and Koliwar reveal diffuse contamination, though of a lesser intensity than the remaining blocks.
The unpredictable nature of arsenic levels was also revealed. Some villages with more than 75% contaminated hand pumps are located along the southern boundary of the 10 km. belt in Barhara, and Udwantnagar, giving credence to the possibility of arsenic contamination further into the district interiors.
Unlike the Patna contaminations, where there was a tapering down of arsenic content in water away from the Ganga Bank, Bhojpur has widespread arsenic occurrences, that also occur at all aquifer levels accessed by the local population. Repeated high arsenic contamination in Udwantnagar forced the Project Investigator to test water samples of Chhotka Sasaram Village adjacent to the southern boundary of the 10 km. belt, and arsenic contamination was found to be very high. Some of the demarcated villages have been abandoned, and have not been subjected to FTK tests.
North of the Ganga River, arsenic hotspots are more frequent 4 – 5 kms. away from the river bank. Here in Vaishali, riverside contamination with over 50 ppb readings was confined to 3 settlements only. A comparatively larger number of contaminated villages are noted nearer the Gandak River in Hajipur Block.
Although much of Raghopur were covered due to annual inundation, all the samples were contaminated. All villages drinking water sources tested here had a number of above 50 ppb contaminated drinking water sources. There was a concentration of > 40 ppb water sources in the narrow land on the north-eastern part of Raghopur. Bidupur had the minimum contamination [18.34%samples contaminated]. The areal spread of contamination is less than in Hajipur and is more on the northern part of this block. Dot clusters again become frequent in Desri and Sahdai Buzurg Blocks. Readings of over 40 ppb are noted along the northern boundary of the study area, suggesting a further northward spread of arsenic contamination.
Maps also revealed the intensity of contamination levels. Raghopur block had no ‘NIL’ samples, and a large percent of low contamination of below 10 ppb. In all the other blocks, contaminations of 11-39 ppb. are significant.
The FTK data maps of Patna and Bhojpur supported the hypothesis of this research team that the areal spread of ground water arsenic contamination bears some correlation to the occurrence of iron-rich newer fluvial deposits in Bihar; hence its frequency nearer the banks of the Ganga. Vaishali maps reveal a different pattern. There are arsenic occurrences in all the villages surveyed in Raghopur island in the south with a few corresponding occurrences hotspots along the northern banks of the river. Immediately to the north of the bank area, are a series of villages with “NIL” FTK readings. Beyond this, further north is a near-contiguous arsenic contamination belt, with intervening non-surveyed villages, that extends roughly parallel to the river bank in an east-west direction. The belt can be traced from Hajipur in the east to Sahdai Buzurg in the west. It is indicative of serious arsenic contamination beyond the arbitrary 10 km. study belt in northern Bihar. The spatial pattern once again highlights the abruptness and unique spread of arsenic in each district of Bihar and calls for immediate hydro-geological analysis.
The flood-prone “diara” areas of Bhagalpur revealed a spatial pattern similar to that of Patna district, with the number of occurrences decreasing away from the river bank. However, Bhagalpur’s contamination extended to even open-wells in Nathnagar . Continuity of hotspots in Kahalgaon and Pirpainti, gives credence to the fact that arsenic mobilization was advancing upstream from the adjacent Bengal Basin along the eastern boundary of this district.

Recommendations-
• A comprehensive study for arsenic contamination in ground water is urgently required all along the banks of Ganga.
• All hand pumps confirmed as having more than 50 ppb. Arsenic content be capped immediately.
• Efforts should be made also to minimize the intake of water having arsenic content of 10 ppb to 50 ppb.
• Gradual, planned reduction of local permissible limit of 50 ppb. to 10 ppb., to avoid long-term assimilation and accumulation of arsenic among the undernourished child and young population
• Identification ,usage and maintenance of arsenic-free aquifers may be carried out in the affected villages identified by this study on priority basis.
• Provisions for alternate safe sources of drinking water, such as piped water, can be implemented wherever possible.
• Intensive awareness campaign should be initiated in arsenic affected villages, educating them about the scourge. Services of nutritional experts can be harnessed, who can identify nutrition-rich agricultural produce and advice the villagers on how to increase the intake of proteins, vitamins and minerals through increased consumption of such local farm products.
• Supply of low-cost, community-based arsenic filters be provided to the affected villages
• Usage of dug wells, with proper water treatment, can be resumed, as the wells of the surveyed area have not tested positive for arsenic contamination till date.
• In all the mitigation work to be adopted, community participation is a basic prerequisite, as it will aid the stakeholders in effective management of arsenic contaminated drinking water sources
• Clinical investigation be initiated in affected villages by a team of doctors
• There is an urgent need for fully-equipped health centres in the arsenic identified areas.
• Further research through bioremediation by “arsenic munchers”[microbes and ferns] should be encouraged, on the principle that nature’s problems can be overwhelmed by identifying solutions existing within nature itself.





References

1. Wedepohl, K.H., Geochim. 1995, Cosmochim. Acta 59, 1217 .
2. Kolker, A., et al., The U.S. Geological Survey WorkShop on Arsenic in the Environment;
www.brr.cr.usgs.gov/Arsenic/
3. Smedley, P.L., & Kinniburgh, D.G., 2002, Appl. Geochem. 17, 517.
4. Webster, J. & Nordstorm, D.K., Arsenic in Groundwater, [Eds.welch, A.H. & Stollenwerk K.G.],
Kluwer, Amsterdam.
5. Nordstorm, D. Kirk, 2002,Worldwide Occurences of Arsenic in Ground Water, Science, Vol. 269, Issue
5576, p2143.
6. Acharya, S. K.,Chakrabarty, P., et al, 1999, “Arsenic Poisoning in Ganges Delta [ Brief
Communication], Nature, 401: 55.
7. “Interim AusAid Guidelines and Operations Procedures for Managing Arsenic in Water Supplies”.
www.ausaid.gov.au/publications/pdf.arsenicguide_feb04.pdf
8. Pal, T., Mukherjee, P.K., & Sengupta, S., Nature of Arsenic pollutants in groundwater of Bengal Basin-
A case study from Baruipur area, West Bengal, India, Current Science, Vol. 82, No. 5, March 2002
9. Welch,A.H.,et al., Groundwater 38, 589 [2000].
10. Mueller, S., et al., USGS Fact Sheet FS-111-01, November 2001.
11. Schreiber, M.J., et al., Hydrogeol. J. 8, 161 [2000]
12. Mukherji, A., Scanlon, B.R., Ghosh A., et al., Regional Hydrochemical study of groundwater arsenic contamination along transects from the Himalayan alluvial deposits to the Indian Shield, Central Gangetic Basin, India - accepted for presentation in GSA Denver Annual Meeting, October 2007, USA.
13. Chakrabarty, D., “ Arsenic Orphans”, Banabithi, Environmental Special Issue, Dept. of Environment
and Forest, Govt. of West Bengal, India, June 1989, 7-16.
14. The World Bank [1999] , Entering the 21st. Century, World Development Report, 1999-2000, Oxford
University Press, N.Y
15. Fazal, A., Kawachi, T., & Ichion, E., “Extent and Severity of Groundwater Arsenic contamination in
Bangladesh”, International Water Resources Association, Water International, Vol. 26, No. 3, 370-
379, Sept. 2001.
16. Astolfi, E., Maccagno, A., et al, 1981, “Relation between Arsenic in Drinking Water and Skin Cancer”,
Biological Trace Element Research, 3, 133-143.
17. Chaudhary, U.K., Biswas, B. K., Roy Choudhury, T., et al, 2000, “Ground water Arsenic Contamination in
Bangladesh and West Bengal, India”, Environmental Health Perspective, 108, 388-397
18.Chadha D.K. and Sinha Roy S.P., “High Incidence of Arsenic in Groundwater in West Bengal”, CGWB,
Ministry of Water Resources, Faridabad, India, July 1999 Report.
19.Chakraborty, D., Samanta, G. et al, 1994, “Arsenic in Groundwater In Six Districts of West Bengal, India:
Biggest arsenic Calamity in the World”, Environ. Geochemistry and Health, 18, 5-15.
20. http://www.sos-arsenic.net/english/natural_origin/research_India.html (4 of 7)6/24/2004 4:24:03 PM
21. Rajiv Gandhi National Drinking Water Mission. http://rural.nic.in/book98-99/chapter7.pdff
22. Fazal, A., Kawachi, T., & Ichion, E., “Validity of the Latest Research Findings on Causes of Groundwater
Arsenic Contamination in Bangladesh”, International Water Resources Association, Water International, Vol 26,
No. 2, 380-389, June 2001.
23. Standard Methods for the Examination of Water and Wastewater, 1996, published jointly by American Public
Health Association [APHA], American Water Works Association and Water Pollution Control Federation
24. Basu, B. & Sil, S., “Arsenic Mapping for North 24 Parganas District of West Bengal- using GIS and Remote Sensing Technology”. www.gisdevelpment.net/application/environment/water/pdf/2004pdff