Groundwater Arsenic Contamination In Bangladesh Research Articles

A Review of Groundwater Arsenic Contamination in Bangladesh: The Millennium Development Goal Era and Beyond.

Arsenic contamination in drinking water has a detrimental impact on human health which profoundly impairs the quality of life. Despite recognition of the adverse health implications of arsenic toxicity, there have been few studies to date to suggest measures that could be taken to overcome arsenic contamination. After the statement in 2000 WHO Bulletin that Bangladesh has been experiencing the largest mass poisoning of population in history, we researched existing literature to assess the magnitude of groundwater arsenic contamination in Bangladesh. The literature reviewed related research that had been initiated and/or completed since the implementation of the Millennium Development Goals (MDGs) under four domains: (1) extent of arsenic contamination; (2) health consequences; (3) mitigation and technologies and (4) future directions. To this means, a review matrix was established for analysis of previous literature based on these four core domains. Our findings revealed that several high-quality research articles were produced at the beginning of the MDG period, but efforts have dwindled in recent years. Furthermore, there were only a few studies conducted that focused on developing suitable solutions for managing arsenic contamination. Although the government of Bangladesh has made its population’s access to safe drinking water a priority agenda item, there are still pockets of the population that continue to suffer from arsenic toxicity due to contaminated water supplies.

Groundwater arsenic contamination in Bangladesh—21 Years of research

Department of Public Health Engineering (DPHE), Bangladesh first identified their groundwater arsenic contamination in 1993. But before the international arsenic conference in Dhaka in February 1998, the problem was not widely accepted. Even in the international arsenic conference in West-Bengal, India in February, 1995, representatives of international agencies in Bangladesh and Bangladesh government attended the conference but they denied the groundwater arsenic contamination in Bangladesh. School of Environmental Studies (SOES), Jadavpur University, Kolkata, India first identified arsenic patient in Bangladesh in 1992 and informed WHO, UNICEF of Bangladesh and Govt. of Bangladesh from April 1994 to August 1995. British Geological Survey (BGS) dug hand tube-wells in Bangladesh in 1980s and early 1990s but they did not test the water for arsenic. Again BGS came back to Bangladesh in 1992 to assess the quality of the water of the tube-wells they installed but they still did not test for arsenic when groundwater arsenic contamination and its health effects in West Bengal in Bengal delta was already published in WHO Bulletin in 1988. From December 1996, SOES in collaboration with Dhaka Community Hospital (DCH), Bangladesh started analyzing hand tube-wells for arsenic from all 64 districts in four geomorphologic regions of Bangladesh. So far over 54,000 tube-well water samples had been analyzed by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). From SOES water analysis data at present we could assess status of arsenic groundwater contamination in four geo-morphological regions of Bangladesh and location of possible arsenic safe groundwater. SOES and DCH also made some preliminary work with their medical team to identify patients suffering from arsenic related diseases. SOES further analyzed few thousands biological samples (hair, nail, urine and skin scales) and foodstuffs for arsenic to know arsenic body burden and people sub-clinically affected. SOES and DCH made a few follow-up studies in some districts to know their overall situations after 9 to 18 years of their first exposure. The overall conclusion from these follow-up studies is (a) villagers are now more aware about the danger of drinking arsenic contaminated water (b) villagers are currently drinking less arsenic contaminated water (c) many villagers in affected village died of cancer (d) arsenic contaminated water is in use for agricultural irrigation and arsenic exposure from food chain could be future danger. Since at present more information is coming about health effects from low arsenic exposure, Bangladesh Government should immediately focus on their huge surface water management and reduce their permissible limit of arsenic in drinking water.

Arsenic contamination of groundwater in Bangladesh: A review

The groundwater arsenic contamination in Bangladesh is known as the largest natural calamity in the world in terms of the affected population. The millions of tube-wells that had been sunk for drinking water supply are now dispensing poisonous arsenic. Consequently, about 80 million people are at risk and another 30 million are potentially exposed to arsenic poisoning. Most of the recognized stages of arsenic poisoning such as melanosis, keratosis, and hyper-keratosis have been identified in Bangladesh. In addition to the health crisis, the arsenic poisoning is affecting the agricultural crops and causing many social problems. The present study is an overview of the groundwater arsenic contamination in Bangladesh. The severity, sources, and causes of arsenic contamination are discussed in this paper. The health, agricultural, and social effects of the arsenic poisoning are highlighted. In addition, a number of urgent needs are given for combating the arsenic disaster. Key words: Agriculture, arsenic mobilization, arsenic poisoning, drinking water, health crisis, social implications, tube-wells.

Evaluation of socio-economic impact of arsenic contamination in Bangladesh

Groundwater arsenic contamination in Bangladesh is reported to be the biggest arsenic disaster in the world in terms of the affected population. Arsenic contamination in groundwater is recognized as the major threats to drinking water and is being the key environmental health problem of 21st century. In Bangladesh Arsenic was first detected in Chapai Nawabgonj, in 1993; since then higher levels of arsenic (exceeding the WHO standard of 0.01 mg/L and Bangladesh standard of 0.05 mg/L) have been identified in various regions of the country. Seventy five million people are at risk and 24 million are potentially exposed to arsenic contamination. From various research works conducted at government and non-government levels and examination of the patients affected with Arsenic pollution, it has been clear that the groundwater of Bangladesh is being contaminated with Arsenic since long period of time. The main consideration of our work is to asses the socio-economic impact on arsenic victims particularly earning male family member, young male, married female, and young female going to be married. The relationship between Arsenicosis and social, educational status was also determined in order to understand the financial influence of arsenic. Key words: Arsenic, socio-economic status, arsenicosis, groundwater.

Status of groundwater arsenic contamination in Bangladesh: A 14-year study report

Since 1996, 52,202 water samples from hand tubewells were analyzed for arsenic (As) by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) from all 64 districts of Bangladesh; 27.2% and 42.1% of the tubewells had As above 50 and 10 μg/l, respectively; 7.5% contained As above 300 μg/l, the concentration predicting overt arsenical skin lesions. The groundwater of 50 districts contained As above the Bangladesh standard for As in drinking water (50 μg/l), and 59 districts had As above the WHO guideline value (10 μg/l). Water analyses from the four principal geomorphological regions of Bangladesh showed that hand tubewells of the Tableland and Hill tract regions are primarily free from As contamination, while the Flood plain and Deltaic region, including the Coastal region, are highly As-contaminated. Arsenic concentration was usually observed to decrease with increasing tubewell depth; however, 16% of tubewells deeper than 100 m, which is often considered to be a safe depth, contained As above 50 μg/l. In tubewells deeper than 350 m, As >50 μg/l has not been found. The estimated number of tubewells in 50 As-affected districts was 4.3 million. Based on the analysis of 52,202 hand tubewell water samples during the last 14 years, we estimate that around 36 million and 22 million people could be drinking As-contaminated water above 10 and 50 μg/l, respectively. However for roughly the last 5 years due to mitigation efforts by the government, non-governmental organizations and international aid agencies, many individuals living in these contaminated areas have been drinking As-safe water. From 50 contaminated districts with tubewell As concentrations >50 μg/l, 52% of sampled hand tubewells contained As <10 μg/l, and these tubewells could be utilized immediately as a source of safe water in these affected regions provided regular monitoring for temporal variation in As concentration. Even in the As-affected Flood plain, sampled tubewells from 22 thanas in 4 districts were almost entirely As-safe. In Bangladesh and West Bengal, India the crisis is not having too little water to satisfy our needs, it is the challenge of managing available water resources. The development of community-specific safe water sources coupled with local participation and education are required to slow the current effects of widespread As poisoning and to prevent this disaster from continuing to plague individuals in the future.

Arsenic-induced myocardial injury: Protective role of Corchorus olitorius leaves

Groundwater arsenic contamination in Bangladesh and its adjoining part of West Bengal (India) is reported to be the biggest arsenic calamity in the world in terms of the affected population. Tossa jute, Corchorus olitorius is a popular crop of this arsenic prone population. The present study was undertaken to evaluate the protective effect of aqueous extract of C. olitorius leaves (AECO) against sodium arsenite (NaAsO 2) induced cardiotoxicity in experimental rats. The animals exposed to NaAsO 2 (10 mg/kg, p.o.) for 10 days exhibited a significant inhibition ( p < 0.01) of superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, glutathione reductase and reduced glutathione level in myocardial tissues of rats. In addition, it significantly increased ( p < 0.01) oxidized glutathione, malondialdehyde and protein carbonyl content in myocardial tissue. Treatment with AECO (50 and 100 mg/kg, p.o.) for 15 days prior to NaAsO 2-intoxication significantly protected cardiac tissue against arsenic-induced oxidative impairment. In addition, AECO pretreatment significantly prevented NaAsO 2 induced hyperlipidemia, cardiac arsenic content and DNA fragmentation in experimental rats. Histological studies of myocardial tissue supported the protective activity of the AECO. The results concluded that the treatment with AECO prior to arsenic intoxication has significant protecting effect against arsenic-induced myocardial injury.

Poisoned backwaters

Charles Harvey and colleagues got to know a snake charmer and his cobras while trying to unravel the mystery of groundwater arsenic contamination in Bangladesh.

A Forensic Look at Groundwater Arsenic Contamination in Bangladesh

A comprehensive forensic analysis of AS contamination in Bangladesh was undertaken using geographic information system (GIS), univariate, and bivariate statistics. The assessment provided the background needed for fine-tuning emerging/evolving methods of spatial mapping based on nonlinear deterministic dynamics and multivariate factorial analyses. Data were derived from a nationwide AS survey completed in 1999 by the British Geological Survey (BGS) in collaboration with the Department of Public Health Engineering (DPHE) of Bangladesh. It was found that the standard deviation of arsenic concentration is highest along the river flood plains of the major rivers. The distribution of arsenic concentration was found to be symmetric in regions of very high mean concentration, while the regions of low and moderate contamination reveal a highly skewed distribution, suggesting the need for data transformation at these points prior to spatial interpolation. The mean value of Ca and Mg concentrations showed a strong spatial similarity in the southwest region of Bangladesh. This spatial similarity was also reflected in terms of skewness of the data. It was inferred that the mapping of AS concentrations at nonsampled locations on the basis of multivariate factorial or regression models may not require the dual presence of both Ca and Mg parameters; hence, one of them is redundant. Both the skewness and kurtosis of the distribution of Si concentration appeared very similar and highly heterogeneous in space, suggesting that Si data require careful transformation prior to modeling only in the smaller scale but not for country-wide/regional purposes. The age of wells was found to be nonlinearly correlated in the southeast region. The correlation of AS with Fe appeared strongest in the southwest region, indicating that the oxidation–reduction hypothesis may be more appropriate as a release mechanism in the southwest region. In another regard, the sulphate concentration was found to be more correlated to AS in the northwest Pleistocene region of Bangladesh, suggesting that the pyrite oxidation hypothesis may be appropriate. Overall, our forensic analysis using GIS revealed useful findings for data transformation and selection of parameters towards spatial mapping based on multivariate factorial and nonlinear deterministic models in the resource-poor settings of developing countries.

Slow arsenic poisoning of the contaminated groundwater users

This paper gives impact of Arsenic contaminated water on human health as well as overview of the extent and severity of groundwater arsenic contamination in Bangladesh. Scalp hair is the most important part of the human body to monitor the accumulation of this type of poison. Therefore, an experiment has been carried out by Neutron Activation Analysis (NAA) at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh on human hair of corresponding tube well water users of these areas to determine the total accumulation of arsenic to their body. Hair samples collected from the region where the groundwater was found highly contaminated with arsenic. The obtained results of arsenic concentration in the lower age (Hb) categories of users (below 12 years of age users) is in the range of 0.33 to 3.29 /gmg/g (ppm) and that in the Hu categories (upper 12 years of age users) is 0.47 to 6.64 μg/g (ppm). Where as maximum permissible range is 1 ppm certified from WHO. Results show that the peoples are highly affected where the groundwater is highly contaminated with arsenic and acts as the primary source of arsenic poisoning among the peoples of those areas. The results indicate that human population is affected with arsenic locally using the contaminated water for a long time.

Investigation of the efficiency of existing iron and arsenic removal plants in Bangladesh

Arsenic in groundwater above 0.05 mg/l was found in 61 out of the total of 64 districts, and 433 out of the total of the 496 thanas in Bangladesh. Groundwater arsenic contamination in Bangladesh is reported to be the biggest arsenic calamity in the world in terms of affected population. Water in around 65% of the areas of Bangladesh contain iron in excess of 2 mg/l, and arsenic has been found to co-exist with iron in many situations. Thus the presently used iron removal plants that operate on the principle of aerating ferrous iron to convert it into ferric iron for precipitation can be a cost-effective solution for treating both iron and arsenic together in the context of Bangladesh. This study investigates the efficiency of 60 arsenic and iron removal plants (AIRPs) presently operating in different geo-hydrological conditions of Bangladesh.

Mapping and interpretation of field data for evaluation and mitigation of groundwater arsenic contamination in Bangladesh

Problems of arsenic contamination have been reported from a large number of aquifers in various parts of the world. Especially in Bangladesh, the presence of arsenic in groundwater has been the major environmental health catastrophe that has affected the source of safe water not only for drinking but also for irrigation purposes. The unavailability and inaccessibility of data and dissemination of proper and rapid information has further reduced the accessibility to safe drinking water for nearly 95% of the population of the country. The development of solutions for the arsenic problem and the allocation of resources for mitigation are information-oriented activities. This paper focuses on the mapping and interpretation of field data (based on a case study area) through the application of GIS for presenting and assessing the scope of the arsenic problem in Bangladesh. The mapping and interpretation is done taking into consideration the geophysical characteristics, socio-economic conditions and socio-cultural behavior of the people living in the study area. The mapping and interpretation technique is aimed at assisting planners and policy makers at the district level to make an assessment about the extent and magnitude of the arsenic problem based on an estimation of the exposed population and the extent and severity of groundwater contamination. In addition, it will enable decision-makers to select possible options and give recommendations based on users' responses. The advantages of this interpretation technique are that the knowledge base is easy to build and any updated information or modifications can be quickly incorporated into the knowledge base.

Validity of the Latest Research Findings on Causes of Groundwater Arsenic Contamination in Bangladesh

The groundwater arsenic contamination problem in Bangladesh is the worst in the world. Two hypotheses are prevailing as the cause (mobilization) of groundwater arsenic contamination in Bangladesh. One is called “pyrite oxidation” and the other is “oxy-hydroxide reduction.” According to the first hypothesis, groundwater arsenic contamination is human-made, which has a relationship with excessive groundwater withdrawal. On the other hand, according to the second one, the contamination is natural. The British Geological Survey (BGS) conducted an investigation to identify the cause of groundwater arsenic contamination in Bangladesh. Based on their findings, they rejected the pyrite oxidation hypothesis and accepted the oxy-hydroxide reduction hypothesis. However, several experts are opposing their research findings. Therefore, a case study is undertaken to examine the validity of the BGS findings. Although we obtained results which are similar to the BGS, the errors in the estimates of percent of wells contaminated, the key parameter of these analyse show that the present as well as BGS results are not dependable to make any conclusion about the cause of contamination. Moreover, the validity test shows that space-dependent relationships among different hydro-geological parameters for the heterogeneous aquifer system are not valid to represent time-dependent phenomena. Therefore, the conclusion made by the BGS is not valid. Still, there is a possibility that the pyrite oxidation hypothesis could be accepted. For a final conclusion we must observe these relationships in a time domain by generating reliable time-dependent field data.

Extent and Severity of Groundwater Arsenic Contamination in Bangladesh

In Bangladesh, the majority of the irrigation and drinking water is supplied from underground sources due to the limitation of surface water. In recent years, arsenic contamination has emerged as a fresh blow to the country. This paper gives an overview of the extent and severity of groundwater arsenic contamination in Bangladesh, as well as a review of the latest statistics and findings of numerous investigations about this issue. Recent reports of the British Geological Survey show that the groundwa-ter in all 61 surveyed districts out of 64 is now contaminated with arsenic. On the other hand, a survey report of School of Environmental Studies, Jadavpur University, and Dhaka Community Hospital shows 47 districts are contaminated. The population exposed to the arsenic poisoning through drinking water is more than 25 million. In regard to arsenic pollution, Bangladesh is the most vulnerable country in the world. Unfortunately, until now, the cause of groundwater arsenic contamination has not been detected. Initially, several anthropogenic sources of arsenic were presented. Gradually, all were rejected based on the field observations. Finally, it was recognized that the source of arsenic is in the geological deposits. The two prevailing hypotheses, pyrite oxidation and oxy-hydroxide reduction, describe the cause of contamination. However, neither has been studied thoroughly with accurate field data. Therefore, the verdict is still out whether to support one hypothesis over the other. Thousands of people are suffering from arsenic diseases ranging from melanosis to skin cancer and gangrene, and many have even died. Unfortunately, there is no specific treatment for chronic arsenicosis, other than ceasing further intake of arsenic contaminated water. To overcome this predicament, awareness of the problem and the creation of watershed management are necessary.

Groundwater Arsenic Contamination in Bangladesh and West Bengal, India

Nine districts in West Bengal, India, and 42 districts in Bangladesh have arsenic levels in groundwater above the World Health Organization maximum permissible limit of 50 microg/L. The area and population of the 42 districts in Bangladesh and the 9 districts in West Bengal are 92,106 km(2) and 79.9 million and 38,865 km(2) and 42.7 million, respectively. In our preliminary study, we have identified 985 arsenic-affected villages in 69 police stations/blocks of nine arsenic-affected districts in West Bengal. In Bangladesh, we have identified 492 affected villages in 141 police stations/blocks of 42 affected districts. To date, we have collected 10,991 water samples from 42 arsenic-affected districts in Bangladesh for analysis, 58,166 water samples from nine arsenic-affected districts in West Bengal. Of the water samples that we analyzed, 59 and 34%, respectively, contained arsenic levels above 50 microg/L. Thousands of hair, nail, and urine samples from people living in arsenic-affected villages have been analyzed to date; Bangladesh and West Bengal, 93 and 77% samples, on an average, contained arsenic above the normal/toxic level. We surveyed 27 of 42 districts in Bangladesh for arsenic patients; we identified patients with arsenical skin lesions in 25 districts. In West Bengal, we identified patients with lesions in seven of nine districts. We examined people from the affected villages at random for arsenical dermatologic features (11,180 and 29,035 from Bangladesh and West Bengal, respectively); 24.47 and 15.02% of those examined, respectively, had skin lesions. After 10 years of study in West Bengal and 5 in Bangladesh, we feel that we have seen only the tip of iceberg.

Groundwater arsenic contamination in Bangladesh and West Bengal, India.

Nine districts in West Bengal, India, and 42 districts in Bangladesh have arsenic levels in groundwater above the World Health Organization maximum permissible limit of 50 microg/L. The area and population of the 42 districts in Bangladesh and the 9 districts in West Bengal are 92,106 km(2) and 79.9 million and 38,865 km(2) and 42.7 million, respectively. In our preliminary study, we have identified 985 arsenic-affected villages in 69 police stations/blocks of nine arsenic-affected districts in West Bengal. In Bangladesh, we have identified 492 affected villages in 141 police stations/blocks of 42 affected districts. To date, we have collected 10,991 water samples from 42 arsenic-affected districts in Bangladesh for analysis, 58,166 water samples from nine arsenic-affected districts in West Bengal. Of the water samples that we analyzed, 59 and 34%, respectively, contained arsenic levels above 50 microg/L. Thousands of hair, nail, and urine samples from people living in arsenic-affected villages have been analyzed to date; Bangladesh and West Bengal, 93 and 77% samples, on an average, contained arsenic above the normal/toxic level. We surveyed 27 of 42 districts in Bangladesh for arsenic patients; we identified patients with arsenical skin lesions in 25 districts. In West Bengal, we identified patients with lesions in seven of nine districts. We examined people from the affected villages at random for arsenical dermatologic features (11,180 and 29,035 from Bangladesh and West Bengal, respectively); 24.47 and 15.02% of those examined, respectively, had skin lesions. After 10 years of study in West Bengal and 5 in Bangladesh, we feel that we have seen only the tip of iceberg.

Possible Arsenic Contamination Free Groundwater Source in Bangladesh

The groundwater arsenic contamination in Bangladesh is a phenomenon of surface ero- sion, transportation and deposition in the form of Delta and ∼lood Plain. While dealing with such geomorphological units like Tableland, Flood Plain, Delta and Hill Tract in Bangladesh, we have found the possibility of having huge arsenic contaminattion free groundwater reservoir in selected areas in Bangladesh. The results presented are the outcome of our last 5 years, field survey analysing for arsenic of water of twentyfive thousand eight hundred ninetyseven hand tubewells in sixtyfour districts of Bangladesh comprising four existing geomorphological regions (a) Deltaic region (including coastal region), (b) Flood Plain, (c) Tableland and (d) Hill Tract. In this report, we will highlight (1) the area in Bangladesh where groundwater is not arsenic contaminated and the' possibility to use shallow hand tubewells as potential groundwater resource for drinking purpose and (2) arsenic contaminations scenario of deep tubewells (above 100 meters) all over Bangladesh and suitable depth in arsenic contaminated area to get safe water.

Nonlinear AC Response in Bilayer Lipid Membrane

The groundwater arsenic contamination in Bangladesh is a phenomenon of surface ero- sion, transportation and deposition in the form of Delta and ∼lood Plain. While dealing with such geomorphological units like Tableland, Flood Plain, Delta and Hill Tract in Bangladesh, we have found the possibility of having huge arsenic contaminattion free groundwater reservoir in selected areas in Bangladesh. The results presented are the outcome of our last 5 years, field survey analysing for arsenic of water of twentyfive thousand eight hundred ninetyseven hand tubewells in sixtyfour districts of Bangladesh comprising four existing geomorphological regions (a) Deltaic region (including coastal region), (b) Flood Plain, (c) Tableland and (d) Hill Tract. In this report, we will highlight (1) the area in Bangladesh where groundwater is not arsenic contaminated and the' possibility to use shallow hand tubewells as potential groundwater resource for drinking purpose and (2) arsenic contaminations scenario of deep tubewells (above 100 meters) all over Bangladesh and suitable depth in arsenic contaminated area to get safe water.