Arsenic Contamination

In the early 1970s, most people living in the countryside relied on surface water -- ponds, or rivers -- to meet their drinking water needs. As a result diseases due to bacteria-contaminated water, such as diarrhoea, dysentery and cholera were extremely widespread. To tackle this problem, and the related problem of drinking water, the government switched to a policy of tapping groundwater. The government began providing villages with tubewells and handpumps, with aid from such organisations as the United Nations Children's Fund (UNICEF) and the World Bank:UNICEF initiated the programme and paid for the first 900,000 tubewells along with its co-sponsor.

Even as millions of dollars were pumped into the country as aid for 'clean' drinking water, and between 8-12 million tubewells installed, the stage got set for what the WHO has called the biggest outbreak of mass poisoning in history tested for arsenic.

Arsenic poisoning was first discovered in West Bengal, India, in the 1980s. In 1993 arsenic-contaminated wells were also discovered in Bangladesh. Finally in 2000, the first comprehensive well-testing program was conducted in Bangladesh by the British Geological Survey.Of the 2,022 wells tested, the survey found 35 percent to contain water with levels of arsenic above Bangladesh’s standard of 50 parts per billion (ppb). 8.4 percent of tested wells were found to contain water with over 300 ppb of arsenic, an unacceptably high level. In contrast, the World Health Organization (WHO) proclaims that water with over 10 ppb arsenic is unsafe to drink. According to a survey done by Bangladesh’s Dhaka Community Hospital and the National Institute for Preventive and Social Medicine, 38 percent of water samples collected from 27 of Bangladesh’s 28 districts were unsuitable for drinking by national Arsenic standards, while 58 percent were unacceptable by WHO standards.

Arsenic Toxicity

Arsenicosis, or arsenic toxicity, develops after two to five years of exposure to arsenic contaminated drinking water, depending on the amount of water consumption and arsenic concentration in water. Initially, the skin begins to darken (called diffuse melanosis). Keratosis is the middle stage of arsenicosis. The skin, in portions, becomes hard and fibrous; it is as if the body has broken out into hard boils, or ulcers. Diffuse or nodular keratosis on the palm of the hand or sole of the foot is a sign of moderately severe toxicity. Rough dry skin, often with palpable nodules on hands, feet and legs means severe toxicity. This can lead to the formation of gangrene, and cancer. While skin lesions are the best-known symptom of arsenicosis they are not life threatening. Furthermore, many people exposed to arsenic will never show skin lesions but may still go on to develop lung, cardiovascular disease and cancer as a direct consequence of this exposure. Children are particularly vulnerable to arsenic poisoning, and are much more likely to face adverse health impacts than adults. There is an increasing body of evidence that prenatal arsenic exposure is associated with significant morbidity and mortality later in life due to lung,

Estimates of the economic impact of poor health arising from arsenic in groundwater in Bangladesh suggest that the cost of inaction is extremely high. The Gross Domestic Product (GDP) output lost due to illness and people becoming unable to work is estimated to be US$23 billion while the cost of treating arsenicrelated diseases is estimated to be much lower at US$0.6 billion for a constant discount rate of 10% over a 50-year period

Tackling the issue

Tackling the issue of arsenic contamination in Bangladesh is much more difficult than experts first predicted. Any proposed solution must take into account the socioeconomic status of Bangladesh and its residents. The technologies used in industrialized nations to treat drinking water and rid it of arsenic are not feasible in Bangladeshi villages. After the detection of arsenic in the groundwater in the 1990s, a series of initiatives were undertaken by the government, non-governmental organizations (NGOs) and development partners. This resulted in a reasonable assessment of the extent of arsenic problem from tube wells. More than 100,000 safe water points have been installed in arsenic affected areas since the discovery of the arsenic problem, with the great majority being deep tube wells. However, the targeting of these water sources to the most affected areas has been poor and an Arsenic Policy Support Unit study found that many of those water points were not operational with the exception of deep tube wells

A primary job for the Bangladeshi government, NGOs, and research teams has been building public awareness of the arsenic problem. The abundance of remote villages, slums, and homeless people make this a particularly difficult task. The government has compiled pamphlets that describe the terrible effects of arsenic poisoning and that explain how to obtain clean drinking water. These pamphlets have been distributed to NGOs and surveyors so that they can be read to villagers in the remotest parts of the country. Furthermore, NGOs and teams of researchers have frequented numerous at-risk villages, tested those with arsenicosis or arsenic poisoning, and taught the people how to obtain clean water.

Many of the techniques they are promoting to obtain clean water are very cheap and do not require large-scale government intervention. Teams of researchers and NGOs, bearing in mind Bangladesh’s poor economic situation, have explored many such inexpensive alternatives to the 1.5 million arsenic-rich tubewells strewn throughout the country. One solution that has already been implemented is the painting of tubewells Although a viable solution, the painting of tubewells and the promotion of well-switching has a few fundamental problems. According to The Lancet, researchers have warned that hundreds of thousands of people in Bangladesh and India may be drinking arsenic-contaminated water because many wells may have been incorrectly labeled as safe by international agencies.

The kits used to test the tubewells are not as dependable as they should be. Accurate arsenic testing is technically difficult and expensive, and arsenic test kits funded by aid agencies have sometimes not been scientifically validated.

The harvesting rainwater, commonly practiced in neighboring Thailand, has been proposed as a solution in these areas and elsewhere in Bangladesh. The annual rainfall in Bangladesh is 1.5–2 meters per year in most areas, with eastern Bangladesh receiving up to 3.5 meters annually. In districts with severely contaminated wells, the harvesting of rainwater is a cheap and clean alternative to the arsenic contaminated well water .Bangladesh’s rainwater is also quite clean; unlike Europe and East Asia, Bangladesh gets very little acid rain.

Both the public and the private sectors have made significant progress towards mitigation. However as of now this problem is far from solved, jeopardizing the progress towards achieving the Millennium Development Goals. Despite massive efforts to provide safe water supplies in arsenic-affected areas, a water quality survey in 2009 by the Bangladesh Bureau of Statistics and UNICEF has found that 12.6% of drinking water samples collected from 13,423 households around the country do not meet the Bangladesh drinking water standard for arsenic. This is equivalent to approximately 20 million people still being exposed to excessive quantities of arsenic.

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- Bangladesh
- South Asia

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