Presence of arsenic in almost all regions of the country is not a recent find. It was more than 20 years ago when the menace called arsenic was found to have invaded many parts of the country. Arsenic at alarmingly high levels was detected in the ground water of 59 out of the 64 districts. The dangerous effects of consumption and even use of arsenic-contaminated water in household chores called for action. Back then there was no ready solution for the government to stop the peril from spreading and taking new locations under its clutch. It was more talked about than actions taken to address it.
It took a while for the government to act in line with anti-arsenic practices in other countries. Millions of wells were tested and hundreds of thousands of safe ones bored to avert a major health crisis. However, over the years, the talks on curbing arsenic menace have gone muted as though the threats are no more. But a latest study reveals that the situation now is scarier than it was initially thought to be.
A study by the Human Rights Watch some time ago reveals that the situation is more dangerous than imagined. Arsenic being a silent killer manifests itself over time in the form of skin lesions, cancer, and cardiovascular and lung illnesses. The study says nearly 20 million people are still drinking arsenic-laced water in Bangladesh. Prevalence of the menace has not declined, the study says, although millions of wells were tested and thousands of safe ones having been bored to avert a major health crisis. The study further adds that around 43,000 Bangladeshis die each year from arsenic-related diseases.
According to another study, in recent decades, some 35-77 million people in Bangladesh have been exposed to toxic levels of arsenic from drinking water, while the total estimated population is about 164 million. The sole dependence on groundwater for drinking purposes in rural Bangladesh, representing nearly 75 per cent of total population, has made the situation much worse.
There are conflicting reports regarding the actual state of arsenic contamination in the country. Initially, way back in 2003, there were some well directed moves to ascertain the situation and some precautionary steps were also taken. According to government claims, 5.0 million rural tube wells were tested and painted green or red to indicate their safe or unsafe types respectably. However, how far this action was able to keep people away from drinking or using the unsafe tube wells and whether that helped mitigate the problem has not been assessed as yet. It is indeed surprising that whatever alertness and mitigation efforts were in place some twenty years ago seem to have dissipated for the most part.
Arsenic is found in water from shallow tube wells across wide swathes of rural Bangladesh. Although deep tube wells can often reach groundwater of better quality, government programmes to install sufficient new wells do not seem to have worked as yet. Researchers say that mass arsenic contamination can be substantially contained by drilling wells deeper than 500 feet. If this is the case, wells and other types of safe water projects to supply water to the worst exposed 20 million people should be provided without delay. The southern part of the country is reportedly the worst victim.
Several techniques have been proposed to remove arsenic from groundwater including precipitation, coagulation/filtration, absorption, ion exchange, lime treatment, oxidation, and membrane filtration. According to experts, using nano-materials, it is possible to effectively destroy microorganisms, adsorb arsenic and fluoride, remove heavy metals and degrade pesticides usually found in water. Researchers have looked at new methods to synthesise iron oxide/hydroxide/oxyhydroxide compositions in the laboratory and used them for water purification. A product called AMRIT, developed by the Indian Institute of Technology Madras, is an affordable water purification technology based on advanced materials, which has been validated for national implementation in India. It has been reported that the technology can remove several anions, especially arsenate and arsenite (two common species present in arsenic-contaminated water) and fluoride from water. Currently, this technology is delivering arsenic-free water to about 10,00,000 people every day.
In order that the anti-arsenic drive is carried out meaningfully, it is of high importance that the government revisits its programmes in the light of the achievements and failures. This will help evaluate and monitor the present situation and at the same time reshape and revise, where necessary, programmes to effectively address the problems in vulnerable locations. It is clear from the scope and nature of the problem that actions to mitigate it have to be long-engaging.
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