Important of those are unholy water, distaste, discoloration, etc. The tubewell initiative, along with the awareness programs, was a great success in substantially bringing down the occurrence of diarrheal diseases and cholera, but unfortunately the discovery of arsenic contamination in the tubewell water and its health effects in the population leads to the reversal of the success story. This sedimentary basin has been formed by deposition of large volumes of arsenic-containing sediments that originated mainly from the Himalayas and was carried down by the mighty GBM rivers during the Pleistocene and Holocene periods.
From these sediments, arsenic is leaching into the groundwater aquifers located in the fan deposit areas and Holocene alluvium. Though the exact mechanism of the arsenic leaching into groundwater is not clear, three mechanisms have been suggested in explaining the process of leaching of arsenic in the groundwater in GBM basin: 1 Arsenical pyrites in the alluvial sediments is oxidized and as a result arsenic is released into the groundwater. The oxidation might have occurred due to the entry of atmospheric oxygen into the aquifers subsequent to heavy withdrawal of ground water through shallow and deep tubewells.
The sources of phosphate are said to be the excessive use of phosphate fertilizer for agriculture, from fermentation or decay of buried peat deposits and other natural organic materials, etc. However, these suggested mechanisms yet remain to be substantiated.
Groundwater in Bangladesh contains a higher concentration of arsenic than surface water sources and the groundwater contains both forms of inorganic arsenic AsIII and AsV , and AsIII is the predominant species. In surface and dugwell water, both inorganic and organic forms are prevalent and the oxidized form of arsenic is the predominant species.
Arsenic contamination has been found more commonly in the tubewells which were installed within the depth of 15—50 m. However, in some areas, the arsenic contamination is found in the tubewells that were installed in greater depths. The arsenic contamination in the deep tubewell DTWs; greater than m deep water is not common. Initially, the arsenic contamination in tubewell water of Bangladesh was thought to be in Gangetic delta plain; later, the contamination was detected in almost all the sedimentary areas of Bangladesh, except in Hilly and Pleistocene Uplands areas Terrace Land.
In the year , the water samples of some tubewells located in the northern bordering area of Bangladesh were examined for arsenic contamination and found to contain arsenic in the range of 0. Following sporadic detection and reporting of arsenic contamination of groundwater, a countrywide screening for arsenic contamination in tubewell water was initiated in The proportion of contamination was The arsenic concentration in the water of the majority of the arsenic-contaminated tubewells was found to be in the range of 0.
The highest concentration of arsenic detected in the tubewell water was 4. Another survey that sampled water from tubewells of 13, households throughout the country revealed that arsenic level in Arsenic is ubiquitous in nature, present in all environmental media and also in human bodies.
Humans are routinely exposed to very small amounts of arsenic through food, water, and air. However, in Bangladesh, groundwater is the main source of arsenic exposure; the population unknowingly receives substantial exposure to arsenic daily through the water they use for drinking and cooking. It has been reported that, on daily basis, a male living in arsenic-contaminated areas on an average ingests 1. Vegetables such as potato, pumpkin, amaranth leaf, and kalmi leaf from contaminated areas were found to contain a high concentration of arsenic; It is known that inorganic arsenic is more toxic to human health than organic arsenic, and the arsenic in groundwater of Bangladesh is predominantly inorganic.
Exposure to arsenic may also occur through inhalation of polluted air, but such exposure in Bangladesh is less likely because there is no such industry which uses arsenic or emits arsenic into the atmosphere. Exposure to arsenic may lead to either acute or chronic toxicity; the amount of arsenic ingested through drinking contaminated tubewell water in Bangladesh is not sufficient to cause acute toxicity.
Prolonged ingestion 2—10 years of arsenic at levels found in tubewell water in Bangladesh may lead to the development of chronic toxicity. In Bangladesh, these dermatological features are considered as the prime manifestations of arsenicosis. The arsenicosis patients were mostly identified by the house-to-house visits in the arsenic-affected areas by the health assistants of DGHS. Health assistants identified the suspected cases that were subsequently examined by medical officers at upazilla health complexes for confirmation.
Among the arsenicosis patients so far identified, a majority of them were found in rural areas and common among the young adults. Males are found to be more affected than females. Arsenicosis was found common among arsenic-exposed population with poor socio-economic conditions. Poor nutrition is also a common influencing factor for developing arsenicosis. People who take less protein are found to be more vulnerable to arsenic toxicity.
Majority of arsenicosis patients in Bangladesh are in mild and moderate stages; severe arsenicosis was less frequently encountered. The common manifestations of arsenicosis reported in Bangladesh includes melanosis Chronic arsenic toxicity may cause multi-organ pathologies and for which arsenicosis patients may also be associated with complications. Regarding mortality, studies revealed an association of mortality with increased exposure to arsenic through drinking water.
It has been estimated that as many as 1 in additional cancer deaths may occur due to lifetime exposure to drinking arsenic-contaminated water containing 0. For the arsenic-exposed population of Bangladesh, mortality risks of lung cancer have been estimated to be There is no specific medicine available for the treatment of arsenicosis. Cessation of further exposure to arsenic by stopping consumption of arsenic-contaminated water both for drinking and cooking purpose and to use arsenic-safe water for both the drinking and cooking purpose are the main management strategies for arsenicosis patients in Bangladesh.
In addition, arsenicosis patients are advised to take locally available protein and vitamin A, E, C rich food. The patients are also advised to take vitamin A beta-carotene , E, and C as a medicinal supplement, and to apply keratolytic ointment to remove keratotic lesions of palm and sole.
These management measures are found to be helpful in the early recovery of mild and moderate arsenicosis patients. But recovery is difficult in severe arsenicosis cases or in cases with complications. Patients treated with spirulina, selenium, or folic acid showed a little improvement. In addition, DGHS has undertaken a number of programs which are community awareness raising regarding arsenic and safe water option; capacity building of the health professionals, management of arsenicosis patients; research and development; and cooperation and coordination with government and non-government organizations with an aim to reduce the suffering of the arsenicosis patients through early identification and provision of management as well as prevention of complications, particularly the cancer.
Consumption of arsenic-safe water is the mainstay both for prevention of exposure to arsenic and management of arsenicosis. To meet this, in , several programs had been undertaken to provide different types of arsenic-safe water options in the arsenic-affected areas of Bangladesh. The safe options included 74, DTWs, 13, rainwater harvesters, 6, DWs, 5, slow sand filters, 3, arsenic iron removal filters, and 3, pond sand filters PSFs.
Among the options, more than two-thirds Other common safe options were DTW But, it has been reported that one-third of these arsenic-safe water options are not being used by the households who have access to these options and at risk of exposure to arsenic-contaminated water. To face the arsenic contamination problem in Bangladesh, government took many initiatives since the identification of arsenic contamination in the tubewell water in Primarily, it was believed that arsenic contamination would be limited in western bordering districts of Bangladesh, particularly in Gangetic Delta region.
With the progress of fact-finding, arsenic contamination of tubewells in various parts of Bangladesh surfaced. To undertake mitigation interventions in terms of arsenic-safe water supply, identification and management of arsenicosis patients, and public awareness, three technical working groups were formed. Initially, two projects were implemented throughout the country; one project was on testing arsenic in tubewells and supply of alternate arsenic-safe water and another one on the identification of arsenicosis case and their management and public awareness regarding arsenic contamination.
To explore the extent of arsenic contamination problem as quickly as possible, Bangladesh government decided to test arsenic in tubewell water throughout the country using arsenic field test kit. The screening for arsenic in tubewells water was initiated in , and up to , water from 51, tubewells was tested for arsenic. In , government formulated Nationwide Communication Strategies with a goal to raise the awareness of the people about the consequences of consuming arsenic through contaminated tubewell water and its economic implications, and to induce behavioral change for expediting the use of arsenic-safe water options.
Government organized training programs on arsenic issues for the medical doctor, nurses, and health auxiliaries to develop a network of arsenic activities from the periphery to the central level. Personnel from national and international NGOs were also involved in the training programs. Considering the magnitude of arsenic contamination problem, government adopted short-term and long-term strategies.
The short-term strategies were related to ongoing activities and the activities to be undertaken in near future. The long-term strategies were to develop sustainable safe water options particularly using surface water, to avoid further arsenic contamination of groundwater and to reduce or prevent the long-term consequences in arsenic-exposed population and to undertake researches. To cope the arsenic contamination situation, a comprehensive approach for arsenic-safe water supply, a project namely Bangladesh Arsenic Mitigation Water Supply Project BAMWSP , was initiated by the government in The BAMWASP conducted a blanket screening of nearly 5 million tubewells nationwide between and for detection of arsenic contamination.
The screening program revealed that During screening, the tubewells which were found to be arsenic contaminated were painted red 3. APSU was set up with an objective to support coordination in addressing arsenic contamination situation; supporting research and training; and supporting stakeholders in promoting effective and sustainable arsenic mitigation. The IPAM was formulated to address the arsenic contamination through a multisectoral approach.
This was a framework plan for the related sectors with short-term, mid-term, and long-term responses. In the national policy, the main approaches that were recommended for the provision of arsenic-safe domestic water supply were:. The national policy was made also to guide the National Water Policy ; however, National Water Policy was revised in giving much emphasis on sustainable safe water options and guidance for the management of various water resources by all concerned governmental and non-governmental agencies including the private users. For this purpose, in the policy, indications and special importance have been given on promotion of efficient and socially responsible water use; delineation of public and private responsibilities, obligations, and accountability including cost sharing and cost recovery; decentralization of water management activities where appropriate; and ensuring community participation.
To prevent the consequences of chronic exposure to arsenic through drinking water, consumption of arsenic-safe water is a must. NPAM provided a guideline for mitigating the effect of arsenic on people and environment in a realistic and sustainable way.
All arsenicosis cases shall be diagnosed and brought under an effective management system. Impact of arsenic on the agricultural environment shall be assessed and addressed. The policy preferred the use of surface water rather than the use of groundwater and recommended the use of locally appropriate alternative option to provide safe water. Neither groundwater nor the surface water can be chosen as a source of water without examination.
Selection of technology should be on the basis of some criteria such as the cost of installation, potential to supply safe water, availability of water around the year, user-friendliness, operation and maintenance cost, and potential for community participation. After 4 years of the initial screening, the nationwide blanket survey of almost 5 million tubewells by BAMWASP reported a similar proportion However, in , the sample survey for arsenic in household water throughout the country reported that This was an indication that there was an increase in the access of the people to arsenic-safe water sources.
However, after 4 years, in , the MICS reported an almost similar However, a large number of safe water options were being installed throughout the country with an aim to combat the groundwater arsenic contamination in Bangladesh as well as to reduce the arsenic exposure to the people by establishing a sustainable arsenic-safe water system. But, it has been reported that one-third of these arsenic-safe water options are not in use or abandoned. The main reasons were the mechanical or technical failure of the options or options are reported to be arsenic contaminated.
Other reasons revealed were lack of maintenance, not repaired, and the negative human behavior such as bad taste and odor, far distance, lack of social acceptability, lack of community participation, ownership ego, and misconception of no damage of health by drinking arsenic-contaminated tubewell water. Considering the above situation, to establish a sustainable arsenic-safe water system, an NGO in Jeshore took initiatives to ensure access of all the people to the safe water options.
The main objective of the initiative was to ensure the availability of regular technical support for the safe water options. This program has been established through the active community participation and support of the local government Union Parishad. This program has been conducted by Asia Arsenic Network AAN since and has been reported to be successful to assure the safe drinking water and a steady supply of water to the community people till now. In the meantime, it is included in the Implementation Plan of Arsenic Mitigation for Water Supply IPAM-WS and a number of organizations implementing similar programs in their working areas reported to be successful in establishing a sustainable arsenic-safe water system.
These sectors develop their own implementation plan for the successful implementation of arsenic mitigation programs in Bangladesh. Consuming arsenic-contaminated tubewell water for a long time may cause chronic toxicity in human health.
Arsenic Contaminated Groundwater and Its Treatment Options in Bangladesh
Arsenicosis is an illness that develops due to chronic low-dose arsenic exposure and is prevalent in arsenic-contaminated areas of Bangladesh. The arsenicosis patient is diagnosed on the basis of WHO arsenicosis case diagnosis protocol which mainly considers the characteristics of skin manifestations and arsenic exposure history. The arsenic-exposed individuals even when consuming the same level of arsenic, all do not develop arsenicosis; the manifestation of arsenicosis possibly depends upon various factors including genetic predisposition.
In Bangladesh, a large number of people are consuming arsenic-contaminated tubewell water but a few of them are reported to be suffering arsenicosis; the prevalence of arsenicosis in arsenic-affected areas has been reported to be Though DGHS has undertaken a number of measures to avoid or reduce underreporting of arsenicosis cases, there remains scope of underreporting during executing the identification program especially due to the ignorance of the people participating in the activities.
It is known that long-term exposure to arsenic may cause or influence the occurrence of multi-organ pathologies especially cancer without the development of the classical signs of arsenicosis. Therefore, people who are chronically exposed to arsenic through consuming arsenic-contaminated water should be monitored regularly for early detection of any illness or pathology attributable to chronic arsenic toxicity.
DGHS should give attention to this problem and undertake special measures for regular monitoring of the arsenic-exposed population. If the effective activities are not taken to monitor the exposed population, the number of cancer cases may overwhelmingly increase. However, it has been reported that the current activities of DGHS relating to arsenic contamination is not in place, healthcare personnel are not helping the arsenic-exposed personnel in seeking medical attention, medical officers are not giving special attention to the arsenicosis patients, arsenicosis patients are discouraged in seeking treatment from the health complex, patients are often not being provided with any antioxidants and keratolytic ointment, and none the less periodic home visits for identification of arsenicosis patients has become none existent.
The management of arsenicosis is a big public health challenge as there is no specific treatment or management for the arsenicosis patients. The mainstay of arsenicosis treatment is to stop further exposure to arsenic through drinking and cooking with arsenic-contaminated water.
Studies have shown a considerable improvement of mild and moderate cases by stopping further intake of arsenic-contaminated water and taking protein-rich food and vitamin A, E, and C supplementation. Another study has demonstrated an improvement of arsenicosis patients to some extent when spirulina is taken in high doses. DGHS provided vitamin A, E, and C and some other antioxidants and keratolytic ointment for arsenicosis patient management through its healthcare facilities free of cost.
The curative treatment for arsenicosis which is practised currently does not show quick improvement if the instructions provided by the physician are not followed by the patients properly. For an effective treatment, long-term case management, even more than years, is often required; in addition, confidence, patience, and adherence of the patients to the management protocol are also essential for a successful management.
On the other hand, some arsenicosis patients do not seek treatment for their illness in early stage rather they seek treatment when arsenicosis becomes severe and complicated, and at this stage, the successful treatment is almost impossible. Thus, all these issues may cause noncompliance of the patient about arsenicosis treatment and may develop misconceptions regarding arsenicosis and its management. Arsenic contamination, arsenicosis, and its complications constitute a substantial public health burden.
Although the provision of arsenic-safe water supply is an important factor for the effective management of arsenicosis which is not under the purview of the DGHS activities, still DGHS can take lead in developing of effective intersectoral cooperation and coordination particularly for arsenic-safe water options. To increase the access to the health care for arsenic victims, adequate facilities and services should be ensured.
On the other hand, the motivational program to raise awareness should be strengthened. For easy accessibility to the treatment facilities, services of the community clinic can be utilized. To provide proper care and treatment of complicated cases, a referral system can be established from community clinic to tertiary level of health care and this service should be under the guidance and support of the local healthcare professional. For follow-up and monitoring of arsenicosis cases, a digital information system may be developed and utilized. The arsenic-exposed population having no arsenicosis should be monitored for early detection of any health effect attributable to chronic arsenic toxicity, especially cancer, for which yearly screening programs can also be organized in arsenic-affected areas.
However, in the current situation of healthcare services, it appears that the arsenicosis patients are not getting adequate and proper treatment and the chronically arsenic-exposed populations are not getting proper attention, which thus can make the mitigation of arsenic contamination problem more difficult. To overcome this crisis, healthcare services need to be organized properly with an aim to give more emphasis on arsenic contamination problem and develop effective strategies and actions so that a sustainable mitigation of arsenic crisis can be achieved.
The problem of arsenic contamination of groundwater is a big public health challenge, and to mitigate the arsenic contamination problem, a multi-sectoral approach needs to be adopted. The challenges are: 1 providing safe drinking water in arsenic-affected areas through sustainable safe water options; 2 involving local government in regular monitoring of the drinking water sources and their maintenance; 3 providing proper management of the arsenicosis patients through an organized follow-up system including surveillance for complications; 4 regular monitoring of arsenic-exposed population and taking action if any health effect attributable to chronic toxicity appears or detected; and 5 encourage research on groundwater arsenic contamination issues and remediation and effect of arsenic toxicity and their management.
Arsenicosis due to arsenic contamination in drinking water is a major public health crisis in Bangladesh. Since the identification of arsenic-contaminated tubewells and arsenicosis patients, government and non-government organizations undertook several activities to stop the arsenic exposure through drinking water by providing alternate sources of arsenic-safe water, identification of arsenicosis patients and their management, and mass awareness programs.
As III is typically oxidised to As V by chemical treatment, but the relatively high cost of oxidants and the formation of toxic by-products are significant drawbacks. Photocatalytic oxidation of As III is being investigated as an alternative to chemical oxidation Figure 2. Arsenic detection has always been challenging, especially on-site 8. On-line determination of arsenic in both the inflow and outflow streams in the ATP could provide several advantages.
In the first instance, it would confirm whether arsenic levels in the outflow were below the maximum contaminant level and therefore confirm that the system was performing to specification. Secondly, it should be possible to then operate the treatment process dynamically, for example, by adjusting the flow rate or the adsorbent if it were approaching saturation. Additionally it should also be possible to then predict when the removal system requires regeneration or replacement and identify early any unexpected failures. Field tests kits, mostly based on colorimetric methods, have been highly criticised for low reliability, time demand, and generation of toxic chemicals Gutzeit method 9, 10 , despite major improvements Other standard spectroscopic methods such as fluorescence or atomic absorption hydride and graphite techniques show excellent sensitivity.
When coupled to chromatography, they are powerful tool for arsenic speciation, but these methods are expensive and laboratory-based, and thus not suited for rural on-site analysis. Voltammetric methods, which use cost effective, portable, low running cost electrochemical systems, are much more suited for rural on-site analysis 12 Figure 3. Although there is an extensive literature on the electrochemical determination of arsenic, primarily using stripping voltammetry 8, 13, 14 , all methods suffer from drawbacks: those developed on solid electrodes such as gold disc usually employ relatively high acidic conditions.
Nevertheless, stripping voltammetry remains at the forefront of on-site arsenic analysis, is formally approved, and is utilised by some companies for metal detections 8. Commercially available systems, however, tend to have high capital costs and may require technical skills to operate.
Figure 2. The resulting As V species can then be easily and efficiently extracted by mineral oxides. Progress also includes the development of a low cost electrochemical sensors that accurately determine arsenic concentrations down to the lower ppb level. This system, patented in three countries Chile, India and Taiwan and widely used in rural areas in India, combines the use of an iron oxide sorbent with subsequent micro filtration. We propose to introduce the mixed mineral oxides instead of the iron oxides and to integrate the sensors at the inlet and outlet of the ATP.
Figure 3. On site electrochemical determination of total arsenic using stripping voltammetry with a gold electrode and the method of standard additions Further Reading The geology of groundwater arsenic contamination, arsenic speciation, toxicology, and methods of remediation have been the subject of many previous articles in the ECG Newsletter and ECG Bulletin. References S. Hug, O. Leupin, M. Environ Health Persp , Chakraborti et al.
[Full text] Arsenic contamination in groundwater in Bangladesh: implications and c | RMHP
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