ARSENIC POLLUTION IN WEST BENGAL
5TH & 6TH of August 2005
 ORGANISED BY:-

SRIKRISHNA COLLEGE
BAGULA.  NADIA
PIN: 741502. INDIA
PHONE: 91-3473-272205
somnathxp@yahoo.com


ABSTRACTS
 
1. Impact of Awareness of Arsenic on Health and Environment among the Rural 
   People: A Case Study on the Villages of North 24-Parganas.

 Pralay O’ Basu, R. Chakraborty and Nirupama Bhattacharya.
 
2. Arsenic Contamination of Drinking Water in Rural Areas Of  India and Its Bearing on Indian Economy.
   Kaustav Bhattadharyya.
 
3. Geochemistry of Arsenic in Ganga Sediment:  A case Study in West Bengal, India.
    S. Chakraborty, B. Nath, J. Jana, P. Mukherjee and D. Chatterjee.
 
4. Geochemistry of Arsenic in the Sediment of  Bengal Delta Plain.
    D. Chatterjee.
 
5. Phytoremediation: A Potential Option to Mitigate Arsenic Contamination in Soil-Water- Plant System.

    Indranil Das, Koushik Ghosh and S.K.Sanyal.
 
6. Dietary Protection against Arsenic Toxicity.                                             
    Madhusnata De.
 
7. Provision of Arsenic-Free Safe Water- an Appropriate Technology:
    Debabrata Ghosh, Ranjan K. Biswas, Morshed Alam  and  Anirban Gupta.
 
8. Arsenic Chemistry in Groundwater in the Bengal Delta Plain: Implications in Agricultural System.
    K. Ghosh, I. Das, S. Saha, G.C. Banik, S. Ghosh, N.C. Maji and S.K. Sanyal.
 
9. Chronic Arsenic Toxicity: Health Issues in West Bengal
    D.N. Guha Mazumder.
 
10. Removal of Arsenic from Drinking Water Using Low Cost Adsorbents.
     Shailesh Gupta and Kamal K. Chaturvedi.
 
11. Arsenic Free Drinking Water: The Gontra Experience.                                     
      Ashok Kundu and Debatra K. Dey.
 
12. Wind Powered Desalination - Drinking Water from the Wind.                      
      Charlie Madden.
 
13. Status of Arsenic Contamination and Hydrogeochemistry of Deeper Groundwater in Eastern Part of River Bhagirathi, West Bengal, India.
     Abhijit Mukherjee and Alan E. Fryar.
 
14. Options for Supplying Arsenic Safe Water to the Community.                        
     Arunabha Majumder.
 
15. Iron Mediated Solar Oxidation and Removal of Arsenic: A Household Treatment Option.
     P. Mukherjee, J. Jana, S. Chakroborty and D. Chatterjee.
 
16. The New Menace in Asia: Arsenic in Groundwater and its Impact on Community Health.
      K.J. Nath.
 
17. Direct Filtration of Surface Water.                                                     
      ZENON Environmental Inc, Ontario, Canada.
      Corresponded by S. Nayak.
 
18. Journey towards Reduction of Sufferings of the People of West Bengal from the Clutch of Arsenic.
      D.P.Poddar, Arup Chakraborty and Tarak Banerjee.
 
19. Overview on Arsenic Contaminated Groundwater and Mitigation Measures in Nadia District – West Bengal.
      B.R. Podder, R. Bhattacharjee and J. Jana.
 
20. Epidemiology of Arsenicosis.                                                            
      D.K.Raut.
 
21. Arsenic Exposure through Drinking Water Creates Health Problem Due to Lack of Awareness.

A.     Roy Chowdhury.
 
22. Alarming Arsenic Attacking Aquifers.                                                    
      Manabendra Sahu.
 
 23. Arsenic Contamination in Groundwater of the Bengal Delta Basin: Implications in Agricultural Systems.
      S. K. Sanyal and S. K. T. Nasar.
 
24. Alternate Land Use Option: A Combat Measure to Reduce Arsenic Loading in Soils of Nadia District, West Bengal.
      Dipak Sarkar.
 
25. Arsenic Hazards in West Bengal: Cause, Effect and the Remedy.                       
      Mitali Sarkar and Sucharita Manna.
 
26. Arsenic Removal Kit.
      S. Sukul                                                                                     
 
 IMPACT OF AWARENESS OF ARSENIC ON HEALTH AND ENVIRONMENT AMONG THE RURAL PEOPLE: A CASE STUDY ON THE VILLAGES OF NORTH 24-PARGANAS
Pralay O’ Basu, Save the Environment, Prof. R. Chakraborty,Calcutta University,  Ms. Nirapuma Bhattacharya
                  Thousands of Indian villages still do not have any local source of drinking water. People often have to walk miles to collect even a pot of drinking water of dubious quality, adding drudgery of their harsh lives. About 2.31 lakhs villages or about 40 per cent of the villages in the country, were designated ‘problem villages’ by the Drinking Water Mission at the commencement of the sixth plan. Theses villages either had no potable water source or, if present, the source was far away from the habitation, or was at a depth of 15m, or at an elevation of more than 100 m. Some of these sources are even contaminated either with guinea worm or cholera germs and typhoid pathogens or the water is chemically contaminated with fluorides and arsenic.                  
                     The massive expansion in exploitation in groundwater resources has high stress in the ground water system and as a result ground water levels have declined by 2 to 4 meters. It has been established that excessive extraction of ground water is a causal factor for arsenic contamination. 
                    To study the Impact of Awareness of Arsenic on Health and Environment among the Rural People a survey has been carried out in six different rural areas of North 24-Parganas of West Bengal – Kamdebkati, Shimulpur, Raghabpur, Kalitala, Betput and Biswashati, which are arsenic pollution prone zone. These villages are located on North 24 Parganas of West Bengal. To show the impact of awareness we have chosen three villages namely Kamdevkati, Shimulpur and Raghabpur where Arsenic Removal Plant have been installed and three villages namely Kalitala, Betpul and Biswashati where Arsenic Removal Plant has not been installed.
                To make the study more comprehensible we have alienated the studied rural community into two categories. The villages where awareness campaigning has been done and Arsenic Removal Plant is installed we have categorized them as group I and the villages where awareness campaigning has not been done and Arsenic Removal Plant has not been set up we have categorized them as group II. For both the group the sample size has been taken the same. During the survey it has been observed that in all the six villages the standard of living and the educational level of the informants have no significant difference. The survey reports that the percentage of people of group I using water from tube well exceeds by 10 % than group II. In group I only 2% people were found not using any protection shield for arsenic whereas in group II 71% people were found not taking protection against arsenic polluted water. The difference between two groups is quite significant despite of having almost same standard of living and education. Awareness can bring about some changes in the perception and the following statements support the words. In group I villages 93 % are aware of the term “Arsenic” and bear a clear concept on it. In-group II villages 66 % are aware of the term “Arsenic” but only 5% people have a superficial understanding of the term.  To study it in more details Logistic Regression method was applied. Thus awareness plays an important role in changing the perception of the people. 
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ARSENIC CONTAMINATION OF DRINKING WATER IN RURAL AREAS
OF INDIA AND ITS BEARING ON INDIAN ECONOMY
 
Kaustav Bhattacharyya
Department of English, Karimpur Pannadevi College
Nadia, West Bengal
 
Water forms a major part of our environment. About 71% of the world’s water Body only 3% is fresh water. Excessive overhauling has dropped the water table at a detrimental level. In addition to that rapid industrialization has caused to the pollution of surface water. But most alarming at present is the arsenic contamination of drinking water. The rural people of India are the most to drink this poisonous water from their tube-wells. Arsenic from rodenticides, larvaecides, herbicides, as waste from copper industries gets deposited in the sub-soil or present in parental form in some layer of soil gets released through some chemical process and dissolves in the water of the layer. An arsenic- affected person suffers from skin –disease and can barely stand, walk or hold anything. A large section of this rural population of India is engaged in Agricultural work. Agriculture is of immense importance in India’s economic Development programme as it is a great source of national income (about 18% of Income by exporting agro-products). Agriculture in India has become very self- Sufficient and resulted in saving the expenditure of foreign money. It has also contributed to rapid industrial development through production –linkage, Demand –linkage and savings & investment –linkage and in flourishing the Internal market of the nation. Economists may opine that decrees in Population in an over-populated country like India will be a blessing but the fact may be otherwise. New markets sprout with population increase resulting in new Income and investment. If arsenic-affectation of rural populace spreads like an Epidemic then there will be massive fall in the number of agro-workers. The Government will not only have to spend in medical purpose, but also have to feed these disabled from other sources. The consumer to producer ratio will Increase which will pressurize the remaining workers and the ultimate result is that per capita production of agro or industrial products will be negative. This Condition may appear as a blow to the golden dream of economic development Of India, if not now at present but at a near future.
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                GEOCHEMISTRY OF ARSENIC IN GANGA SEDIMENT: A CASE STUDY IN WEST BENGAL, INDIA

 S. Chakraborty 1,2, B. Nath2, J. Jana2, P. Mukherjee2 & D. Chatterjee2
 
1 Department of Chemistry, Kanchrapara College, Kanchrapara, North 24 Parganas
2 Department of Chemistry, University of Kalyani, Kalyani, Nadia-741235
 
Arsenic Contamination in groundwater has been envisaged as a global issue in the perspective of population exposure and area coverage. A vast alluvium plain (34,000sqkm)has been affected with elevated level of arsenic in groundwater with high arsenic concentration(50-500mgL-1).The contamination mostly found in upper delta plain(UDP) and comprises of younger Ganga sediments. The lithology is dominated by sand to silty loam to silt with fining upward sequences. The major identified minerals (Quartz, Muscovite, Clinochlore chlorite) by XRD do not vary with depth. The organic matter content in sediment is ~1%.The groundwater chemistry of the affected area reflects high concentration of HCO3 - , PO4 -3 and NO3 -, SO4 -2, F- concentrations are low. Field parameters (pH, Eh, DO) which show that Eh is generally negative, pH is usually near neutral. Adsorption study of arsenate on pure Muscovite mica shows maxima at pH 5.5. Therefore weathered mica particles can play an important role in mobilization/immobilization of arsenic under local reducing condition. The proper geochemical understanding of controls will help to demonstrate the future trend of arsenic contamination in Bengal Delta Plain (West Bengal).
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GEOCHEMISTRY OF ARSENIC IN THE SEDIMENT OF BENGAL DELTA PLAIN
 
D. Chatterjee,

Department of Chemistry, University of Kalyani, Kalyani-741 235, India

Dissolved high natural inorganic arsenic is now causing serious threat to human health in Bengal Delta Plain (West Bengal and Bangladesh). In West Bengal, the occurrence of arsenic in groundwater is often exceeding the WHO guideline value (10 ppb) and National Standard (50ppb) and millions of water wells are now contaminated with arsenic. The area (~ 70 km north of Calcutta, 22o-24o N, 87o-89o E) covering an integral part of world’s largest Ganga-Brahmaputra young deltaic alluvium (lowland Holocene sediment). Filtered (0.45 mm) water and sediment samples were collected from the field and divided in two sets, (i) acidified (0.2% HNO3 v/v) for cation analysis, (ii) un-acidified for anion analysis. [As]T, [Fe]T, As (III) and organic carbon of the sediments were determined. Results of the contaminated wells reveal that the waters are in general Ca-HCO3- (pH ~6.7-7.7) type and fresh (conductivity 350-1290 ms cm-1). The aquifer is anoxic in nature (Eh < -0.07- -0.34mV) with high bicarbonate (260-740 mgL-1) and redox sensitive species (As, Fe, Mn, NH4+). Groundwater samples are high in As (>0.02 ppm), Fe (>0.2 ppm, Fe[II] 0.01-0.2 mmolL-1), Mn (>0.45 ppm), HCO3- (>470 ppm) and often P (0.59 ppm) concentration and low in chloride (<55 ppm) concentration. Water quality indicates that iron-reducing condition is prevailing and thermodynamically favored process. The alkalinity of the pore water increases (8.1±0.5 mmolL-1) due to the recharge from Hooghly river (25 mmolL-1) and this helps to facilitate the breakdown of organic matter and this ultimately leads to dissolution of iron oxides. High groundwater temperature (26-31oC) and pCO2 further enhance the microbial processes that responsible for local reducing condition. PHREEQC programme reveals that the groundwater is supersaturated with calcite, siderite and goethite. This means the iron hydroxide and carbonates are playing a vital role in mobilizing redox sensitive species (As) in groundwater. Sediment organic carbon (1%) and [As]T (17.5 mgkg-1) are relatively low and there was no buried peat in the sediment. From the study it may be concluded that organic matter has driven the microbiological process rather formation of peat, which has been previously hypothesized.
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PHYTOREMEDIATION: A POTENTIAL OPTION TO MITIGATE ARSENIC CONTAMINATION IN SOIL-WATER- PLANT SYSTEM

Indranil Das, Koushik Ghosh and S.K.Sanyal


Bidhan Chandra Krishi Viswavidyalaya,


Mohanpur – 741 252, Nadia, West Bengal

 
 
                  Arsenic is of great environmental concern due to extensive contamination of groundwater in the Bengal delta basin with this toxin, thereby causing carcinogenic toxicity to millions of people. Soil contamination with arsenic input through the vehicle of contaminated groundwater being used for irrigation, may prove detrimental to plant through its uptake to the toxic level. Indeed, the possibility of such toxin entering the human food web, along with biomagnifications up in the food chain, through plant uptake of arsenic is of immediate concern. In this regard, phytoremediation is a developing technology that offers a potential avenue to address the problem of arsenic contamination of soil-crop system. In this context, however, the need of the hour is to develop reliable and cost-effective phytoremediation technologies capable of bringing down arsenic in groundwater (and in soils as well) to environmentally acceptable levels.
                        The success of such remediation would evidently depend on establishing a selected plant community. For this, a systematic search for phytoaccumulating or phytoexcluding plant species is necessary.  Although a beginning has been made in this regard to identify arsenic accumulating plant species at BCKV over the past 4-5 years period (as well as elsewhere), much more sustained research studies need to be undertaken to focus attention on these aspects in order to achieve tangible success. Some of the techniques in this field which may prove useful include phytodegradation (the process in which the given plant species are capable of metabolizing and destroying the contaminant within the plant tissues), phytovolatilization or biotransformation (the process employing microorganisms and plants to transform the toxicants into the volatile forms to escape to the atmosphere), rhizofiltration (the process in which plants, used for clean-up, accumulate the toxicants), etc. Continued research on these aspects of phytoremediation is essential.
                        Several weed species, namely Ludwigia parviflora, Filmbristylis sp., Ageratum conyzoides, Eleusine indica, etc., which were identified by us, showed promise of accumulating  substantial amounts of arsenic (e.g., 50 times or even more) in their plant biomass when grown in the arsenic-affected areas, in comparison with the situation where such weeds grew in arsenic-free areas under observation. The latter may prove attractive due to its relative cost-effectiveness, coupled with its aesthetic nature, namely the use of plants for “clean-up” activities.
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DIETARY PROTECTION AGAINST ARSENIC TOXICITY
Madhusnata De
Associate Professor, Dept. of Genetics
Vivekananda Institute of Medical Sciences
Ramakrishna Mission Seva Pratishthan
99, Sarat Bose Road, Kolkata-700026
 
In West Bengal, India earlier studies has recorded enhanced arsenic content, ranging between 0.2 to 0.64 mg/L drinking water from shallow tube wells in 5 districts (Chakravarty and Saha, 1987). During the past years, increased arsenic content, of as much as 0.8 mg/L has been recorded in tube well water from 159 villages in 7 more districts of West Bengal. The human safety limit permissible by the WHO is 0.05 mg/L. Almost 30% of the villagers drinking the contaminated water showed arsenicals dermatitis and keratosis, in addition to other symptoms of arsenic poisoning (Anandabazar, 1993). The worst hit areas are Malda, Mursidabad, Nadia, Hooghly, Howrah, Burdwan, South and North 24 Parganas, as identified by Geographic Information System (Statesman, 2000). The average concentration of arsenic in groundwater is reported to be 0.2mg/L, reaching a maximum of 3.7 mg/L in the affected areas (Chakravarty et al 1998).
 
The extensive arsenic poisoning of the human population in West Bengal, India (Mandal et al, 1996) and adjoining Bangladesh (Dhar et al, 1997) through high levels of arsenic in drinking water from tube wells has led to investigation on different methods to prevent harmful effects. Attempts are being made by our group to protect against the effects of arsenic in drinking water through dietary supplementation.
 
The problems of protection against exposure to arsenic through drinking water has assumed considerable importance, due to the widespread effects of arsenic poisoning of large human populations numbering several millions in West Bengal and Bangladesh. The effects of environmental toxicants like arsenic were related to life style and also to different kinds of addiction.
 
About 5.3 millions people in West Bengal live in areas where arsenic concentration is above the permissible limit. So, dietary protectants can only serve as useful remedies to defend against the ill effects of arsenic.
 
Tea is well-known beverage, brewed from leaf of Camelia sinensis and widely consumed throughout the World. Commercial tea is available in several forms, amongst which black tea is most prevalent in India and green tea in China and Japan. Consumption of tea has been associated with anti-mutagenic and possible anti carcinogenic effects (Yang 1997, Yang and Wang, 1993). Black tea was used in reducing the cytotoxic effects of inorganic arsenic in mice when given as a regular supplementation. This work is of special importance in view of the widespread exposure of human population in several districts of West Bengal, India and Bangladesh to arsenic through drinking water from tube wells.
 
The mode of protection may be attributed to the combined antioxidant and scavenging properties of the components of tea infusion (Mukerjee et al, 1999). The results were significant in view of the widespread effects of arsenic toxicity on human populations exposed to arsenic through drinking water. Black tea infusion is a common everyday drink and can be utilized for protection of human population.
 
A total of 100 cases from VIKAS KENDRA, Atghara, aged between 13 to 68 years, who were drinking arsenic contaminated water since their birth, are the subjects of the present study. Oral smears were obtained and the percentages of micronuclei were determined.                  Concentration of arsenic in hair and nail were analyzed from those individuals. Percentage of micronuclei was increased in exposed group and mitotic index was low in these groups. 
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           PROVISION OF ARSENIC-FREE SAFE WATER - AN APPROPRIATE TECHNOLOGY
 
Debabrata Ghosh, Ranjan K. Biswas, Morshed Alam, Anirban Gupta
Environmental Engineering Cell, Civil Engineering Department,
Bengal Engineering and Science University, Shibpur, Howrah - 711103
 
               Arsenic has been found in groundwater in many parts of the world & is posing threat to human health. It is a serious problem in 79 blocks of 9 districts of West Bengal. In the seventies, the use of surface water was replaced by heavy dependence of ground water in West Bengal in order to overcome the problem of microbiologically unsafe untreated surface water. Surface and dug well water sources cannot be used either for drinking or for cooking purpose because these are not properly preserved. A large portion of these arsenic-affected areas are rural & there are no other alternative source of safe water like pipeline water supply & as a result, people living in these areas are fully dependent on tube-well water, which often is contaminated with higher levels of arsenic. The reported clinical manifestation resulting from ingestion of arsenic contaminated drinking water includes weakness, respiratory problem, keratosis, melanosis, peripheral neuropathy & even cancer.  Since people in these areas mostly belong to low-income group having poor nutritional dietary intake, they are very much affected by arsenic related diseases. Provision of safe water is of urgent necessity in the arsenic-prone areas. Before any long-term solutions like treatment and supply of surface water can be implemented, spot treatment units to treat the contaminated tubewell water is of great help to save millions of people from arsenic toxicity. There are many processes in use for removal of arsenic from groundwater like chemical precipitation, adsorption, ion exchange & membrane filtration. BESUS (Bengal Engineering & Science University, Shibpur) has developed a process based on adsorption of arsenic from water by activated alumina. BESUS has started working in this field in 1996 and has been able to install about 140 arsenic removal units in West Bengal till date, which are running successfully, some of which are running for more than eight years. Many of the units are providing safe drinking & cooking water to more than 150 families in each case. BESUS promotes community participation for long-term sustainability where local water committees take charge of operation and maintenance of the filter & tube well. Community based arsenic removal filters, which are in use, has been made sustainable by mass awareness campaign taken up by BESUS for use of arsenic free safe water. The technology adopted by BESUS is user friendly and media (activated alumina) can be regenerated at low cost for reuse.  Many of the arsenic-patients are showing significant improvement in their health condition. The health & condition of the arsenic-affected patients improved significantly after consuming arsenic-safe water. This paper describes one of the cost effective technology for supplying of arsenic free safe water for rural mass.
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 ARSENIC CHEMISTRY IN GROUNDWATER IN THE BENGAL DELTA PLAIN: IMPLICATIONS IN AGRICULTURAL SYSTEM

K. Ghosh, I. Das, S. Saha, G.C. Banik, S. Ghosh, N.C. Maji and S.K. Sanyal

Bidhan Chandra Krishi Viswavidyalaya, Mohanpur – 741252, Nadia, West Bengal

 Arsenic (As), a toxic trace element, is of great environmental concern due to its presence in soil, water, plant and animal continuum. Arsenic in terrestrial environment may have had its origin in natural and anthropogenic sources. Arsenic contamination of groundwater in the Gangetic alluvial zones of West Bengal has assumed the proportion of a drinking water-related disaster in recent years with reports of arsenic related health hazards for millions of people. The groundwater As concentration (50 – 1600 mg/L), reported from the affected areas of West Bengal, are several orders of magnitude higher than the stipulated Indian standard for the permissible limit in drinking water (50 mg/L), which is also the maximum acceptable concentration, MAC, for drinking water in Bangladesh, India and several other countries), as well as the WHO guideline value (10 mg/L). The arsenic loading of the groundwater which is used as irrigation source varied from 0.06 to 0.53 mg/L in Nonaghata mouza of the Haringhata block of Nadia district in West Bengal. A high degree of such contamination was also found in different parts of the affected-belt, to name a few, Gotera and Ghentugachi mouzas of Chakadaha block of Nadia district (ranging from trace to 0.89 mg/L); Ambikanagar, Chakla, Iajpur and Chyangdana villages under Deganga block of North 24- Parganas district of West Bengal (varying from 0.05 to 0.50 mg/L), etc. by a group of researchers at Bidhan Chandra Krishi Viswavidyalaya.
 
Soil, though an important sink for arsenic, may nevertheless facilitate its access to plant through leaching, methylation or erosion. The clay fraction, iron and aluminum oxide and organic carbon pool in soil have frequently been implicated in the sorption of different species of arsenic by soils. Sequential extraction of soil arsenic helps one to differentiate between arsenic that is readily labile, and accessible to plant uptake, and that which is bound strongly by the soil components in soil matrix.
 
Some of our research studies, conducted at the selected affected areas, revealed that the total and Olsen extractable (i.e., 0.5M NaHCO3, pH 8.5 – extractable As which constitutes the soil As pool amenable to plant uptake) arsenic varied from 8.4 mg/kg to 24.3 mg/kg and from 2.90 mg/kg to 15.8 mg/kg, respectively, in the affected soils of West Bengal. The soil arsenic contents of these areas were generally higher than those reported for the soils of several other countries like Argentina, China, Italy, Mexico, France, Australia, etc.
 
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CHRONIC ARSENIC TOXICITY: HEALTH ISSUES IN WEST BENGAL

 D.N. Guha Mazumder
 
Member, Task Force on Arsenic Govt. of West Bengal
Professor and Head Dept. of Medicine and Gastroenterology (Retd.)
Inst. Post. Grad. Med. Edu. & Res. Kolkata – 700 020.
 
 Many aquifers in various parts of the world have been found to be contaminated with arsenic (As) at concentration above 50 µg/l.  Of these the most noteworthy occurrences are in large areas of West Bengal (India) and Bangladesh, Taiwan, Northern China, Hungary, Mexico, many parts of the USA, Chile and Argentina.
Chronic arsenic toxicity due to drinking arsenic-contaminated water has been one of the worst environmental health hazards, affecting West Bengal since the early eighties.  It is suspected that 6 million people are exposed to As contaminated water in 72 blocks of 8 districts of the state, the highest As level reaching up to 3400 µg/l (safe level < 50µg/l).  The source of contamination is suspected to be geological.  Detailed clinical examination and investigation of 248 such patients revealed protean clinical manifestations of such toxicity.  Over and above hyperpigmentation and keratosis, weakness, anaemia, burning sensation of eyes, solid swelling of legs, liver fibrosis, chronic lung disease gangrene of toes, neuropathy, and skin cancer are some of the other manifestations.
A cross-sectional survey involving 7683 participants of all ages was conducted in an arsenic-affected region between April 1995 and March 1996.  Out of a population of 7683 surveyed, 3467 and 4216 people consumed water containing As below and above 0.05 mg/l, respectively.  Except pain abdomen the prevalence of all other clinical manifestations tested (e.g., pigmentation, keratosis, Hepatomegaly, weakness, nausea, lung disease and neuropathy) were found to be significantly higher in As exposed people (water As > 0.05mg/l) compared to control population (water As level < 0.05mg/l).  The prevalence of pigmentation and keratosis, hepatomegaly, chronic respiratory disease and weakness rose significantly with increasing arsenic concentrations in drinking water.  The respiratory effects were most pronounced in individuals with high arsenic water concentrations who also had skin lesion.  Therapy with chelating agent DMSA was not found to be superior to placebo effect.  However, therapy with DMPS caused significant improvement of clinical condition of chronic arsenicosis patients.
However, this medicine is not available in India and is very costly. Supportive treatment could help in reducing many symptoms of the patients. People should be advised to stop drinking As contaminated water or exposure to As from any other source.  The various clinical manifestations should be treated symptomatically.
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REMOVAL OF ARSENIC FROM DRINKING WATER USING
LOW COST ADSORBENTS
 
Shailesh Gupta and Kamal K. Chaturvedi
Department of Biochemistry
Govt. Model Autonomous Holkar Science College Indore (M.P.)
            Arsenic is a commonly occurring toxic metal in natural ecosystem. Inorganic arsenic is an established human carcinogen. Inhalation of arsenic dust particles and ingestion from drinking water are the main sources of human exposures. The purpose of this research is to convert the agricultural wastes, bagasse and bagasse fly ash which are low-cost, ecofriendly, renewable and widely available wastes into inexpensive and effective adsorbent materials for arsenic REMOVAL from drinking water. Adsorption by these materials can be used as an alternative to conventional methods which are usually associated with high costs and thus do not suit the needs of developing countries. Batch experiments for As(III) and As(V) with bagasse and its fly ash were conducted as a function of adsorbent dose, contact time, adsorbate concentration and pH to establish optimum conditions for remediation. Bagasse removes 86.3% and bagasse fly ash removes 98% of arsenic from its initial concentration of 500mg/L. RESULTS WERE FURTHER CONFIRMED BY SEM & XRD.

Keywords – Arsenic, bagasse, bagasse fly ash, drinking water.
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ARSENIC FREE DRINKING WATER: THE GONTRA EXPERIENCE
 Ashok Kundu and Debatra K. Dey
Rishi Bankim Chandra College & Srikrishna College
West Bengal

Providing arsenic free drinking water to vast rural masses in eight contaminated districts of West Bengal is a major challenge to the planners, policy makers and executors. Both the state and market are virtually unable to supply such basic requirements for saving the human lives.  Gontra, a small village in South Nadia is a unique example of collaboration between Bengal Engineering College, NGO, Co – Operative society and local communities to provide arsenic free drinking water to the poor villagers at minimum cost for the last five years.  The paper attempts to find out the role of local institution and community behind its success.  It will try to enquire about advantages, disadvantages and the replicability of such a community – based model.
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WIND POWERED DESALINATION - DRINKING WATER FROM THE WIND
 
Charlie Madden
Managing Director
Wind - Water Pty Ltd.Australia
 
We are in the process of developing the first version of Wind - Water based on raw distillation that will produce 400 litres a day of pure drinking water. This will be 98% arsenic free.
We are then going on to increase the output to maybe 80,000 litres a day by a different approach. The power comes from a 10kW vertical axis wind turbine. The photo of the half size prototype is attached. In the current machine being built, this drives a vertical shaft at 100 rpm which drives the pumps, fans and joule heater on the ground. The ground equipment is in stainless steel, the rotor in carbon fibre epoxy and the tower in mild steel. The wind range is 4 - 12 m/s after which it shuts itself down. The pumps load the churn which heats the water. The fans lift off the vapour which condenses on passing through a heat exchanger cooled by the water coming in, which it heats up. A patent has been applied for. We are a small company in Adelaide, and any help would be welcome.
 
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Status of arsenic contamination aND hydrogeochemistry of deeper groundwater IN eastern part of river Bhagirathi, West Bengal, India
 
Abhijit Mukherjee and Alan E. Fryar
Department of Geological Sciences
University of Kentucky, Lexington, USA
 
Formidable concentrations of arsenic (As) in groundwater of the Bengal basin have been acclaimed as the greatest mass poisoning in human history. Previous workers have identified elevated levels of As mostly in the shallower Holocene aquifer of Bengal. Many workers have suggested that groundwater at depth of 100m or more below surface is an alternate safe potable water source. We are investigating this hypothesis and contradicting the traditional belief.  Our study includes an area of about 12,000 km2 of the districts of Murshidabad, Nadia, North and South 24 Parganas.
The study area is predominantly underlain by a single regional aquifer system with multiple discontinuous aquitards in the southern part (south of mid North 24 Parganas).  There are some deeper isolated aquifers with distinct chemistry from this main aquifer. Based on the study of deeper groundwater from the regional aquifer, we observed that 61% and 33% of our locations have As concentrations ³ 10 ppb and ³ 50 ppb, respectively. The As is mostly present in dissolved phase (£ 0.45mm) with 64% of it as more hazardous As (III). Elevated As was not found in deeper water of South 24 Parganas. The highest concentration of As recorded is 223 ppb. The water has very low dissolved oxygen (0.49 to 2.32 ppm), pH of 6.8 to 8.1, SC ranging from 619 to 1810 ms/cm, and alkalinity (as HCO3-) from 367 to 649 ppm. Fe(II) is mostly £ 2 ppm but may reach 7 ppm. The median Fe value (1053 ppb) for deeper wells (³100m) is less than the median for shallower wells (1505 ppb). The lack of correlation between As and Mn (r2 = 0.05) and weak correlation with Fe (total) and Fe(II) (r2 = 0.22 and r2 = 0.41) suggests that As concentrations in the deeper aquifer may not reflect As sorption onto Mn minerals and weak sorption on reduced Fe minerals, which is contrary to previous theories. A Piper plot indicates that the predominant hydrochemical facies is Ca2+–HCO3-. Some trends of salt-water mixing and CaCO3 dissolution have also been noted. Na+ was found to be the dominant cation in some wells in North 24 Parganas. Median values of Ba and Sr were 196 and 377 ppb, respectively. Sr varies significantly with Ca + Mg (r2 = 0.54), indicating a possible contribution of Sr from Ca-Mg mineral weathering.. Concentrations of other trace metals (Be, Co, Li, Ni, Sb, Se, V, U and Th) were below detection limits. While PO43- and S2- were not detected in any of the wells, CH4, SO42- and NH4+ were observed in several wells. 18O concentrations averaged -4.8‰ standard mean ocean water (SMOW) and d2H concentrations averaged -29.9‰ SMOW. Values of 18O plotted versus d2H scatter around the global meteoric water line, indicating recharge from precipitation with some effects of evaporation. 18O and d2H generally became more positive toward the south. 18O values generally fall between –3‰ and –6‰, which is consistent with water < 3 ka old (P.K.Aggarwal et al., IAEA TC Project BGD/8/016, 2000).
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 Options for supplying arsenic safe water to the community
 Arunabha Majumder
 Director- Professor
Dept. of Sanitary Engineering
All India Institute of hygiene & Public Health, Kolkata
 
Supply of water from surface water sources e.g. river, lake etc. after purifying the water though conventional treatment (coagulation-flocculation-sedimentation-rapid sand filtration-chlorination). The water is distributed through pipe-network system.
Installing deep tubewells for abstracting water from arsenic free aquifers. The tubewells need to be sealed effectively during installation so as to prevent seepage of arsenic contaminated water from upper aquifer to lower aquifer.
Collection of water through rain water harvesting and supplying the same after appropriate treatment. Pond water can also be used as arsenic free water after treating it by HRF-SSF technique.
Supplying arsenic safe water after removing arsenic through different treatment options. Such system could be for domestic as well as for community (hand pump attached).
In West Bengal, around 1900 hand pump attached arsenic removal units (ARU) have been installed under different programmes. Following principles were adopted by different manufacturers.
       i.        Co-precipitation (AIIH&PH model) ---
Chemical Use : Bleaching powder and alum.
Process : Flush mixing, coagulation flocculation - sedimentation - upflow filtration.
     ii.        Adsorbtion  ---
Chemical Use :
i)                     Activated Alumina
ii)                   Ferric hydroxide
Different graded activated alumina and ferric hydroxide are used. Some manufacturers import media for manufacture of ARU.
    iii.        Ion-Exchange : Use of "Bucket of  Resin" for removal of arsenic.
   iv.        Membrane filtration Technique / Reverse Osmosis.
Domestic units for removal of arsenic comprising of co-precipitation and adsorbtion (AA) are in use in West Bengal.
Community based management system is being developed by AIIH&PH for operation and maintenance of hand pump attached arsenic removal units under ICEF-AIIH&PH project. NGO partners are working for arsenic problem mitigation programme.
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 IRON MEDIATED SOLAR OXIDATION AND REMOVAL OF ARSENIC: A HOUSEHOLD TREATMENT OPTION

P. Mukherjee, J. Jana, S. Chakroborty, D. Chatterjee

Dept. of Chemistry. University of Kalyani
 
Arsenic (As) has now been recognized as most widespread natural contaminant and threatens the health of millions of people worldwide. Many large and small communities experience As contamination in groundwater and/or drinking water supplies in many parts of the world and significantly in south-east Asia. The scale of the problem is serious and unprecedented in West Bengal and Bangladesh (Bengal Delta Plain, BDP) both in terms of human exposure and geographical area coverage where As concentration in contaminated wells exceeds both WHO guideline value (10 mgL-1) and stipulated National standard (50 mgL-1) for both Bangladesh and India. Dissolved forms of As in the BDP water include arsenite (~50-70%), arsenate (~30-50%) and ultra-trace amount of MMA (monomethylarsonic acid) and DMA (dimethylarsinic acid). Arsenite and arsenate species can interchange depending on redox potential (Eh), pH and biological processes. Conventional treatment techniques to remove As from groundwater are cost prohibitive and difficult to practice in rural areas of BDP. Instead of using hazardous chemicals (e.g. chlorine, ozone in conventional method) As from groundwater can also be removed by exposure to sunlight (solar oxidation) in presence of dissolved iron (Fe) and a chelating agent (citrate, naturally available) followed by filtration with cloth or simple decantation. The technique is user friendly, low cost and easy to perform by the rural mass of the BDP.
 
Key-words- solar oxidation, iron, chelating agent, arsenite, arsenate, MMA, DMA

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THE NEW MENACE IN ASIA:
ARSENIC IN GROUNDWATER
AND ITS IMPACT ON COMMUNITY HEALTH
 
Prof. K.J. Nath
Chairman, Arsenic Task Force, Govt. of West Bengal, India
President, Institute of Public Health Engineers, India
Member, Scientific Advisory Board & SEA Regional Co-ordinator,
International Forum on Home Hygiene, Geneva
Principal Scientific Advisor, Sulabh International Social Service Organization
 
 
       Reports from as many as 25 countries show mild to severe contamination of Groundwater with Arsenic. The countries include Argentina, Australia, Bangladesh, Cambodia, Canada, Chile, China, Greece, Hungary, India, Japan, Laos, Mexico, Mongolia, Myanmar, Nepal, New Zealand, Pakistan, Peru, Philippines, Romania, South Africa, Taiwan, Thailand, United States of America and Vietnam.
 
        Arsenic contamination in groundwater has emerged as a major water quality problem causing serious health hazards in West Bengal & Bangladesh, where vast areas have been affected in recent years. Though a scientific epidemiological assessment of the problem is yet to be made, a major portion of the population in these countries are living in the hydrogeologically risk zone. The present crisis is primarily due to geomorphological reasons, though there have been reports of anthropogenic contamination of water & air from some countries including China. The commonly reported symptoms of chronic arsenic poisoning include hyperpigmentation, dipigmentation and keratosis. Skin cancer & internal cancer can also occur. The transfer of arsenic from soil to water and vice versa is dependent on soil water interaction. The mechanism of the Arsenic release in the ground water is not well understood and its impact on community health and the disease burden associated with the same are yet to be ascertained. An effective plan of action for combating the problem in the affected countries would require a complete understanding of the possible causes and a realistic estimation of the extent & magnitude of arsenic contamination and its possible health effects.
 
           The paper presents an overview of the problem of arsenic contamination in groundwater in India, Bangladesh & other South East Asian countries. The hydro-geological causes and the extent & magnitude of the problem have been discussed. Various issues related to Arsenic contamination, eg. release and spreading mechanism of arsenic, effects of arsenic on human health, remedial action & technology options etc have been discussed in the context of experiences of various organizations in these countries. The problem of water quality surveillance, setting of national Standard of arsenic concentration in ground water and the cost and other related problem of enforcing the same have also been discussed.
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DIRECT FILTRATION OF SURFACE WATER
ZENON Environmental Inc
Oakville Ontario Canada L6M4B2
Corresponded by Mr. Suresh Nayak 
 Business Development Manager. South-East Asia.
  
The City of Scottsdale, Arizona has historically obtained its Salt River Project (SRP) water allotment as treated water from the City of Phoenix Verde Water Treatment Plant (WTP). However, this agreement expires in 2005, and the City has decided to build its own WTP.The new plant will require reliable treatment of challenging surface water from the Arizona Canal, which has a TSS range between 18 and 59 mg/l, and a pH range of 7.7 to 8.5(average pH is 8.1). Turbidity and TOC are between 5-25 NTU and 2-3.6 mg/l, respectively. Water temperature varies between 10 and 30°C. The arsenic concentration can range from 4-20 µg/l in the raw water.
Therefore an additional water quality objective is to reduce the arsenic concentration to below the revised US EPA MCL of 10 µg/l using coagulant addition.
In January 2000, Scottsdale’s City Council authorized a pilot program to evaluate the latest water treatment technologies. Following the pilot testing, ZENON’s ZeeWeed® 500 series membrane technology was selected based on a comprehensive present worth evaluation. The latest ZeeWeed® 500 series product, the ZeeWeed® 500d, was later found to offer considerable additional cost savings over the module first piloted. Subsequent testing verified its performance. Final operating parameters were as follows:
 
• Flux –30 GFD
• Recovery – 90%
• 15 mg/L ferric salt
 
Chaparral WTP Treated Water Pilot Results
 
Raw Water
Filtered Water
Turbidity (NTU)
8.0
<0.03
TOC (mg/L)
2.9
2.0
TSS mg/L)
38
0
As (µg/L)
6.6
<1.8*
 
*membrane filtration + 15mg/L ferric sulfate coagulant.
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JOURNEY TOWARDS REDUCTION OF SUFFERINGS OF THE PEOPLE OF WEST BENGAL FROM THE CLUTCH OF ARSENIC
 
D.P.Poddar, Arup Chakraborty & Tarak Banerjee

West Bengal Voluntary Health Association
19,A Dr. Sundari Mohan Avenue, Kolkata -700014

The contamination of arsenic in the ground water in various districts of West Bengal, including the city of Kolkata has become the major area of concern. Approximately the arsenic effected population in West Bengal touches about 4 crores 20 lakhs.  In seventy six blocks of nine district of West Bengal arsenic contamination in drinking water have gone to the extent of 0.05 mg which is much beyond the WHO permissible limit 0.01mg/lt. Arsenic contamination in ground water of West Bengal has turned to be the greatest arsenical calamity of the world. West Bengal Voluntary Health Association responded to the need way back in the year 2000.
WBVHA initiated its activity towards arsenic mitigation program in the district of Malda , N- 24 Pargana, Nadia and Murshidabad with the assistance of India Canada Environment facility in collaboration with All India Institute of Hygiene and Public Health . WBVHA in consultation with different experts felt the need to aware and sensitize the community people on arsenic and the probable consequences through various media. In relation to sensitize various sections of the community, 10 trainings for the paramedics were organized in the above mentioned 4 districts of West Bengal.
The objective behind carrying out these activities is to sensitize maximum number of effected population as well as to create an alternate support system and build up a sense of ownership to combat this menace. With the activities still in full swing, the impacts of the various programs have started pouring in.
For consolidation of the program as well as the sustainability point of view, WBVHA planned to create or strengthen community based groups, preferably Self Help Groups, and through these grass root groups more and more people will be sensitized.   With an aim to provide more and more number of people, the safe drinking water, in the arsenic effected area, as well as adding partially towards rural economy, WBVHA plan to help local potter to make low cost domestic filter and market in the effected area.
We believe that even though the journey towards reduction of the sufferings of the small section of the people has just began and the gravity of the problem is too heavy, however with the kind assistance of all sections of the people, changes in the scenario is inevitable.
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OVERVIEW ON ARSENIC CONTAMINATED GROUNDWATER AND MITIGATION MEASURES IN NADIA DISTRICT – WEST BENGAL
 
B.R. Podder, R. Bhattacharjee, J. Jana.
 
P.H. Engineering Dte.
Nadia Division,
Government of West Bengal.
D.C. Building, 1st Floor,
Kalyani, District – Nadia. 
 
The district Nadia lies in the alluvial deltaic plain of Ganga and its tributaries. Its latitude in between 230 52’ 30” N – 230 05’ 40” N and longitude in between 880 08’ 10” E – 880 48’ 15” E. Ground water development has started extensively in the early 70s as a results of green revolution to encounter the water demands for irrigation, as well as human consumption. Arsenic poisoning was sporadically reported in early 80s in few pockets (Nadia, Murshidabad, Maldah, and South 24 Parganas) of West Bengal. Presently the risk population in the rural areas is 38.53 lakhs covering all the blocks (seventeen) of Nadia District. The health affect (mostly skin lesions, arsenicosis etc.) was attributed to prolong consumption of arsenic contaminated ground water with elevated level (As >50 mgl–1). The arsenic related health problems show a decreasing trend as soon as population is provided with arsenic safe drinking water.
 
Arsenic contaminated well normally (³50 mgl –1) occur within the depth range of 20 – 100 m bgl, while more than 100 m bgl tube well are relatively safe (<50 mgl–1). It is observed that shallowest well (< 20 m) also tend to have low arsenic concentration. Similarly, more than 100 m bgl the arsenic contamination is higher than 50 mgl –1 . Several remedial options have been suggested by the scientist and engineers so far and adopted as well as implemented by the subsequent action plans for supply of safe drinking water.
 
In addition to district level laboratory some laboratories have been set up under joint Action Plan at the doorstep of rural people. The options like Arsenic Treatment Units over hand pump fitted tube wells, sinking of deeper aquifer tube wells and also ring wells have been implemented as mitigation measures by the P.H.E.D. Domestic arsenic removal filter has also been developed and being utilized by the rural people under Joint Plan of Action of Government of West Bengal and UNICEF. Another option like pipe water supply scheme with Arsenic cum Iron Removal Plant has also found to be satisfactory.
 
In this district so many water bodies like lakes, ponds, rivers etc. are commonly available and free from arsenic. For long term mitigation measures surface water is the only safe alternative option for drinking as well as domestic purpose. Some surface water based water supply schemes are being prepared for implementation.
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 EPIDEMIOLOGY OF ARSENICOSIS

 D.K. Raut
 Professor, Dept. Of Epidemiology
 AIIH & PH, Kolkata-73
 
          Arsenic occurs naturally in all environmental media and usually presents in the form of compounds with sulphur and with many metals. The average concentration in the earth's crust is about 2mg/kg. Due to its natural occurrence, humans are universally exposed to arsenic in various forms. Exposure of general population occurs mainly through arsenic present in food and drinking water. In some areas, the natural high arsenic content of the drinking water above WHO permissible limit of 0.05 mg/l (50ug/l) has caused endemic, chronic arsenic poisoning. In the humans, the total daily intake of arsenic is greatly influenced by the amount of seafood in the diet, and consumers may reach several thousands ug. of total arsenic per day. However, 85-95% of the arsenic present in the marine products is present as the much less toxic, organic compounds.
 
          Environmental arsenic exposure has received attention primarily because of disease resulting from ingestion of water containing inorganic arsenic. Disease manifestations have been those of chronic arsenic poisoning, examples include nonmalignant cutaneous changes such as hyperpigmentation and hyperkeratosis, skin cancers,"Black foot disease (a form of arsenic induced peripheral vascular insufficiency leading to gangrene), peripheral neuropathy plus hematopoetic, renal and hepatic toxicity.
 
          The classic description of arsenic poisoning relies on reports of suicidal or homicidal arsenic ingestion. The cardinal features of acute or subacute arsenic poisoning are gastrointestinal e.g. nausea, vomiting, abdominal cramps and diarrhea that may be bloody, chronic disease, such as peripheral neuropathy, can also follow acute exposures.
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 ARSENIC EXPOSURE THROUGH DRINKING WATER CREATES HEALTH PROBLEM DUE TO LACK OF AWARENESS
 
                                                             A. Roy Chowdhury

Regional Occupational Health Centre (E)
(Indian Council of Medical Research)
Block DP, Sector V, Salt Lake City,
Calcutta – 700 091, INDIA.
 
          Out of eighteen districts in West Bengal, nine districts are severely affected by ground water of high arsenic content. This arsenic contaminated water is used by the rural villagers. Most of the affected villages are Nadia, Murshidabad, 24-parganas (N&S). Large number of community is affected due to arsenic exposure through drinking water. This particular environmental calamity was first noted in the year 1981 by a group of biomedical scientists of School of Tropical Medicine, Calcutta. The identification of the arsenic exposed health impairment was first noted by Prof. K.C. Saha. The main feature of this arsenic exposure is known as arsenicosis. Skin pigmentation (rain drop), mild keratosis are the early diagnostic manifestation in arsenicosis. In severe cases, enlargement of liver, which is supported by increased levels of SGOT, SGPT along with the keratosis in palm and sole, nodular enlargement and different pattern of neuropathy were seen among the chronic exposed person.

          In this context, some measures may be undertaken to reduce the arsenic toxicity and for that awareness generation is highly essential. In the beginning of this awareness, one must know the nutrition supplementation, i.e. high amino acid containing cereal, vegetables, along with antioxidants. Secondly, to avoid the use of arsenic contaminated water in cooking and drinking purpose, low cost home made filter may be used for getting arsenic free water. Therefore, some simple and home made technology certainly reduce the arsenic toxicity. The present discussion regarding the awareness among the community will certainly be helpful to avoid arsenic exposure.
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ALARMING ARSENIC ATTACKING AQUIFERS
 Manabendra Sahu
 Dept. of  Chemistry
Karimpur Pannadevi College, Nadia, West Bengal
 
Arsenic is a metalloid. It is very fatal for human if consumed. Used as an Insecticide, or wastes from industries containing arsenic gets deposited in the sub–soil or as present from in pyrites layer, due to some chemical Reaction the layer disrupts and arsenic gets mixed with water. It is soluble in Water and cannot be observed in naked eye. It is present in two oxidation state +5 and +3, of which the latter is more lethal.
 
According to W.H.O. the permissible limit of arsenic is 10 microgram per litre of drinking water. If taken for a long time, a person suffers from Arsenicosis: Blackish-grey spots appear on the skin (Melanosis), the skin slough and Roughens (Keratosis). Thereafter the patient suffers from Gastroenteritis and Liver, Kidney, lungs start to malfunction and possibility of cancer of skin and Lungs becomes more. At present nine districts of West Bengal are arsenic Affected where some water samples show that the limit is above 25 times than the permissible limit.
 
Arsenic reacts with-SH group of enzyme and defunctions it. The energy realized from the cell due to Kreb`s Cycle is disturbed. Arsenic reacts with the Enzyme called pyruvate dehydrogenase and dysfunctions it by forming a Complex compound. Arsenic hinders the synthesis of ATP in the bio-chemical Process. Protein is coagulated due to presence of a large amount of arsenic.
 
No medicine has yet been discovered to fully cure a patient suffering from Arsenicosis. Drinking safe water, some physical exercise as recommended by the physician, intake of nutritious food is some of the remedial measures. Surface water, any water other than ground water, such as rainwater and water from dug wells are free from arsenic. Government should frame and implement Laws regarding digging of tube-wells at anywhere and should arouse Consciousness among the people against the evil of arsenic.
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ARSENIC CONTAMINATION IN GROUNDWATER OF THE BENGAL DELTA BASIN: IMPLICATIONS IN AGRICULTURAL SYSTEMS
 
S. K. Sanyal and S. K. T. Nasar
Bidhan Chandra Krishi Viswavidyalaya,
Mohanpur-741252, Nadia, West Bengal 
 
Arsenic contamination in groundwater has been reported from time to time from West Bengal (India) and countries like Bangaladesh, USA, Argentina, Chile, Mexico, Taiwan, Hungary, Finland and others. The toxicity of arsenic compounds in groundwater/soil environment depends largely on its form (organic or inorganic), and if in inorganic forms, then on its redox status and pH. Thus, the arsenites are much more soluble, mobile and toxic than arsenates in aquatic and soil environments.
High arsenic concentration in groundwater is generally associated with the geochemical environments of volcanic deposits, geothermal systems and basin-fill deposits of alluvial lacustrine origin. As regards the widespread arsenic contamination in groundwater in parts of West Bengal (India) and Bangladesh, confined within the delta bound by the rivers Bhagirathi and Ganga-Padma, two major hypotheses, both of geogenic origin, have been proposed. These are the pyrite oxidation hypothesis and the oxyhydroxide reduction hypothesis. The latter seems to be more consistent with the experimental observations on the nature of the aquifer in the affected delta.
The main focus of attention of such arsenic contamination in the Bengal delta basin, until recently, has been exclusively on such contamination in groundwater derived drinking water. It is only rather recently that the agricultural sector, which receives the major share of such contaminated groundwater as irrigation source, has received attention for quantifying the influence of the said toxin (i.e., arsenic) on the soil-crop-animal continuum. Indeed, this Viswavidyalaya led, for the first time, an inter-disciplinary, inter-institutional study, initially funded by the Indian Council of Agricultural Research (and subsequently by the State and Central Governments), characterizing the aforesaid effect of arsenic on soil-crop-animal system. These findings have aptly demonstrated the pathways, other than drinking water, through which arsenic may have access to human food-web.
 A large number of important results have accumulated from such studies, not only on the characterization of the entire gamut of intricacies of arsenic contamination spectrum in the said continuum, but also on a number of effective remedial measures to contain the toxic effect of arsenic. In particular, the surface water bodies, located in the affected belt, have remained largely free of arsenic. This tends to suggest that the soil, which receives arsenic contaminated irrigation water, acts as an effective sink to contain the toxin, thereby preventing the surface run-off to carry it to the adjoining water bodies. The retention of arsenic by the soil organic fraction and the incorporated organics in the affected sites of study has been amply demonstrated, so also the release potential of arsenic from the resulting organo-arsenic complexes by the competing oxyanions such as phosphate and nitrate. Furthermore, the effective retention of arsenic by the soil colloidal fraction was shown to be essentially a ligand-exchange phenomenon, influencing the surface charge characteristics of the given soils. The latter may have far-reaching consequences on the appropriate management interventions.
                The application of FYM and phosphate was found to have opposing effect on release of native and applied arsenic in the contaminated soils, with FYM reducing such release, thereby tending to moderate the toxic effect of arsenic in soil-plant system. This agreed well with the findings of a supporting pot-culture experiment, raising rice, which is particularly susceptible to arsenic toxicity.
Indeed different crop plants raised in a crop cafeteria experiment exhibited varying tendencies to accumulate arsenic. Such accumulation in different plant parts also tended to fall off in the following sequence: root > stem > leaf > economic produce. Moreover, inclusion of pluses/other legumes / green manure crops in the cropping sequences, coupled with organic manure addition, was found helpful in moderating arsenic build-up in soil and plant parts.
Field studies, examining lowland rice (boro paddy), revealed that the extractable arsenic in soil and also the plant loading of arsenic was drastically reduced by zinc application to soil in which this micronutrient was marginal to deficient. The grain yield of summer (boro) rice in such studies was also found not to vary significantly between the treatments of continuous ponding and judicious intermittent ponding; however, the latter saved the contaminated irrigation (ground) water, thereby bringing less of the toxin to the soil/crop system.
The arsenic decontaminating ability of the microorganisms, prevalent in the contaminated soils, was also monitored. This led to the identification of two genera of blue-green algae (BGA) (namely, Anabaena sp. and Nostoc sp.), and four different types of bacteria showing promise of arsenic decontamination ability. Furthermore, several weed species, growing in the wild in the affected areas of study, namely Ludwigia parviflora, Lantana camara, Eleusine indica, Filmbristylis sp., etc. also showed promise of accumulating considerable amounts of arsenic in their vegetative biomass. The latter could be of importance in regard to cost-effective phytoremediation options for the given arsenic contamination problem.
An important point to note here is that as one passes from the contaminated groundwater to crop plants via soil, the arsenic concentration gets gradually built up, leading to its magnification.
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ALTERNATE LAND USE OPTION: A COMBAT MEASURE TO REDUCE ARSENIC LOADING IN SOILS OF NADIA DISTRICT, WEST BENGAL

Dipak Sarkar
Principal Scientist and Head
National Bureau of Soil Survey and Land Use Planning (ICAR)
Sector-II, Block-DK, Salt Lake, Kolkata – 700 091

                Arsenic (As) - a metalloid ubiquitous in nature and belonging to groupVB of the periodic table can exist in many oxidation states and thus can form many inorganic and organic compounds. However, organic compounds of arsenic are much less toxic than their inorganic counterparts and the trivalent arsenic (arsenite) are more toxic than pentavalent state. The clay fraction, amorphous iron & aluminium oxides and organic carbon have frequently been implicated in sorption of As by soils. Detailed soil survey conducted  recently in Chakdah block of Nadia district, West Bengal belonging to alluvial tract of Indo-Gangetic plain (IGP) revealed alarming arsenic contamination in ground water leading to arsenic pollution in soil crop environment. Notwithstanding, the seasonal fluctuations the average arsenic concentration in the ground water was found to be 0.25 mg Asl-1 which far exceed the maximum recommended concentration of 0.1 mg As l-1 of the contaminant with respect to its use both for drinking as well as for irrigation purposes. Therefore, judicious use of such arsenic contaminated ground water is the prime need of the hour for which rationalization of irrigation schedule is supposed to be most essential. With a view to sustaining the resource quality by way of reducing arsenic contamination, lifting of lesser quantity of irrigation water becomes imperative posing greater emphasis for rain fed rice cultivation along with alternate land use options. Soil-site suitability evaluation study suggested sesame to be the most suitable pre-kharif crop after requisite soil-pH correction and potato as moderately to marginally suitable rabi crop as alternate land use options having lesser water requirement and thereby can be instrumental in reducing arsenic contamination in the soils of the area.
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ARSENIC HAZARDS IN WEST BENGAL: CAUSE, EFFECT AND THE REMEDY
Mitali Sarkar and Sucharita Manna
Department of Chemistry
Kalyani – 741 235
West Bengal, INDIA
University of Kalyani
 
Arsenic poisoning has become one of the biggest environmental, health and social disasters of recent days all over the world. The problem is much serious in West Bengal, where a huge population under nine districts is badly affected. The average arsenic concentration in groundwater is found to be 22.5 times of the maximum permissible limit (0.01 mg/L), set by WHO and at places crosses even 50 times the said limit. Unfortunately, such a dangerously contaminated groundwater is the principal source of drinking as well as irrigation water of our state. A huge region under the kingdom of plants, animals and human beings is therefore compelled to intake the poison day after day. Considering the magnitude of this problem, it is very much urgent to develop an efficient technique for its treatment from aquatic environment
Researchers have been working to develop possible treatment options of arsenic contaminated water under laboratory and field conditions. Among the various techniques available adsorption is proved to be a viable one. Activated carbon, when used as an adsorbent of arsenic, yields sufficiently good result, but the cost of treatment is generally very high. In our present study fly ash, obtained as a waste product from Thermal Power Plants, is used to remove arsenic from aqueous samples. The process is found suitable in case of laboratory and real samples. Although the adsorption efficiency is found low when compared to that of activated carbon, the waste material can be utilized as a potential adsorbent considering its cost and easy availability.
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 ARSENIC REMOVAL KIT
S. Sukul
B-15/93, Kalyani-741235
 W.B., India
 
A simple, cheap, reliable and reproducible Arsenic Removal Kit has been developed for 98 % removal of arsenic from arsenic contaminated drinking water. The kit is in pouch form containing a chemical composition prepared using charcoal, bentonite powder, sodium chloride, ferrous sulphate and potassium permanganate. This is a household preparation, which will save people from arsenic poisoning by providing safe drinking water.

Key Words: Arsenic Removal Kit, arsenic removal, drinking water.
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