UNICEF and other international organizations were on a mission to help countries access clean water throughout the developing world. In an effort to get people to stop drinking dirty surface water, they worked with the Bangladeshi government to promote the use of shallow, hand-pumped wells.
It seemed to be a textbook solution: cheap; easy to maintain; a collaboration of government, community, and private sector; and focused on attacking the root cause instead of the symptoms. An estimated 10 million hand-pumped tube wells were drilled across the country, at first by the government, UNICEF, and other donors and NGOs, and later by individuals and families. The project appeared to be a roaring success.
The purity of the water was even tested by the British Geological Survey. Unfortunately, they did not test for arsenic. Particles of iron oxide with arsenic chemically bound to them are carried into Bangladesh from the Himalayan Mountains by the fast-moving Ganges and Brahmaputra rivers. These particles are carried from the cold, high altitudes to the sluggish waters of tropical marshes and swamps, where they are broken down by oxygen-seeking bacteria, releasing the arsenic into the groundwater.
This is the layer of water tapped by high-density hand-pumped tube-wells used by the rural population. Agricultural laborers are particularly susceptible to the poison, as they work long hours in the hot sun, drink a lot of water, and rely on rice which also takes up arsenic as their staple food. Already weakened immune systems from poor nutrition and a paucity of health care will compound the effects. A wide swath of the wells was found to be contaminated, thought to expose more than 57 million people.
Educational programs urged people to seek out new sources of drinking water and contaminated wells were marked with red paint. But little was done — aside from the digging of a limited number of new wells — to tap cleaner supplies. Many of those who could switched to safer wells, but most people had no options.
As the case of Uddin and his neighbors illustrates, local patronage and nepotism are part of the failure to deal with the problem. At this point, the consensus among engineers and geologists is that deeper wells, lower than feet, would provide arsenic-safe water that could each serve 10 or more families.
Filtering surface water can also work in some cases. The better and longer term — but more expensive — solution is providing piped water to an entire community using a central filtration plant, which has so far been tried successfully in a handful of test cases. At issue is a question that goes beyond the case of Bangladesh to a larger dilemma facing the powerful institutions that get involved around the world: Who is responsible when an effort to do good ends up doing harm?
The charity or foreign aid agency? The government that received the aid? The consulting firms that worked on the project? With no accountability in sight, the people who were supposed to be the ones being helped are left to pick up the pieces.
In the wake of the massive testing program after the arsenic was discovered, interest from government and donors faded in the last decade. Kazi Matin Ahmed, Chairman of the Department of Geology at the University of Dhaka who has been working with the Columbia University team, says that the Bangladeshi government possesses most of the resources to address the problem.
I n the district of Faridpur, a rural area near Dhaka on the banks of the Padma River, Abdul Latif Sheikh lives in what seems like an idyllic village compound, with a brown calf in the yard and the sound of roosters crowing as they bobble around the water pump. Sheikh is strapping and tall, but his voice rings with disappointment.
He and his wife Rokeya drank for years from arsenic contaminated well. Rokeya has dark marks on her hands, wrists, and feet. She picks at them as he talks. She is sick and losing weight. She has no time to go to the doctor; since her husband cannot work, she must bring in the money. Their son and daughter live with them. Since she knows her well is contaminated, Rokeya fetches water from the well at the local fisheries office.
Many in the village do the same, assuming that because it is a government well, it is safe. In fact, the well has no markings indicating it has been tested.
Bangladesh is already well-known in public health circles for its successful programs to end open-defecation and reduce child mortality. The claimants are Bangladeshi villagers who drank arsenic-contaminated water from wells dug by the BGS during the s and early s.
The number of claimants could run into thousands. They intend to file a group-action suit in Britain alleging that the BGS's failure to test the well-water for arsenic makes the agency responsible for their poisoning. On legal advice, BGS officials declined to be interviewed about the allegations. The suit is being prepared by Leigh, Day and Co. Some researchers fear that the threat of such suits may deter scientists from working on aid projects in the developing world.
The claim against the BGS is expected to hang on the accusation that, when its scientists returned to Bangladesh in to assess the safety of the water in the wells they had dug, they did not test for arsenic. The arsenic crisis in Bangladesh was caused by the sinking of over one million wells by foreign aid agencies and the Bangladeshi government from the s.
The effort — intended to reduce the incidence of water-borne disease in the region — has instead put millions of Bangladeshis at risk of poisoning. The problem was not noticed until victims began showing external symptoms of arsenic poisoning: calluses on the palms and soles of feet, leading to skin cancers. The Bangladeshi government considered suing UNICEF, according to lawyers at Leigh, Day, but did not do so because there is a consensus that the arsenic problem couldn't have been anticipated then.
Expert opinion on that point is divided. But other experts point out that Chakraborti's work was not published in the international scientific literature, and only came to widespread attention in Affected school-age children are prevented from attending schools and are avoided by their friends and classmates.
Often, when employers discover their affliction, the affected workers immediately lose their jobs. Once detected and dismissed from an employment because of arsenicosis, no other local employer will provide them with alternative employment. Under such circumstances, many have no option but to migrate to urban areas. The worst affected people in Bangladesh are poor women and children. In poor rural households, it is the adult female who is the generally the most undernourished and most vulnerable to disease.
When the husband discovers symptoms of arsenicosis on her body, he often refuses to keep her under the same roof. If the woman is fortunate, the husband simply sends her back to her parents for treatment. In most case, however, the husband finds it too risky to maintain the marital relationship and seeks divorce.
Women are unable to get married and wives have been abandoned by their husband. As a result, the divorced women find no place in the society and, with their children, become destitute. In villages, it becomes a problem for parents to get their affected daughters married.
Arsenicosis also affects the productivity of victims who are often so incapacitated that they are unable to work and become liabilities for their families. The children of the poor have been drinking contaminated water since their birth. They, too, may eventually suffer arsenicosis. It will be very difficult, perhaps impossible, for the parents of an affected young woman to find a groom for her without offering a huge dowry. The provision of dowry is already a difficult, social problem, but will be further compounded by the arsenic problem.
There are two different, but not mutually exclusive, approaches to minimizing the human health impacts of arsenic contamination ofgroundwater:. Prevention: To prevent further exposure to Arsenic contamination, it is important to screen of all tube well and population to identify contaminated ones and level of contamination. The GoB has already finished the screening of the tube well. Once the tube well is detected with higher concentration of arsenic than national standard, the tube is marked with red paint and with green paint which is safe to drink Figure 6.
The next steps to provide arsenic free water to all the populations. The people are promoted to take water from the sources which are arsenic free. The people are advised to drink surface water after certain amount treatment with disinfectant or they also promoted for rain water harvesting. The people who are able to bear the cost are suggested to drill tube well in the deep aquifer where water is arsenic free. Where alternate options are not available are suggested and supported to make water arsenic free.
There are several techniques to make the water arsenic free. Based on these techniques different tools are developed for wide distribution to the arsenic exposed area of Bangladesh.
The most commonly used arsenic removal units are: 1. Fill and Draw Units 2. Stevens Institute Technology Unit. In Fill and Draw Unit, the tank is filled with arsenic contaminated water and required quantity of oxidant and coagulant are added to the water.
The water is then mixed for 30 seconds by rotating the mixing device at the rate of 60 rpm and left overnight for sedimentation. In Figure 7 shows a locally adopted fills and draw unit. Activated alumina, Al2O3, having good sorptive surface is an effective medium for arsenic removal. When water passes through a packed column of activated alumina, the impurities including arsenic present in water are adsorbed on the surfaces of activated alumina grains.
It was found that bed volumes could be treated satisfying the Bangladesh drinking water standard of 50 ppb Ahmed M. Stevens Institute Technology Units also uses two buckets, one to mix with iron sulphate and calcium hypochloride supplied in packets and the other to separate flocs by the processes of sedimentation and filtration Figure 9. The chemicals form visible large flocs on mixing by stirring with stick.
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