Bangladesh is one of the richest countries of the world in Water resources. Per capita availability of water is perhaps highest in that country. It has a major river system of the world consisting of Brahmaputra river and many large subsidiary rivers like Padma. In addition the country gets bountiful rain fall for almost six to eight months of the year.
Bangladesh river systems literally pour billions of liters of water in the country. Yet all this water seems to be harming this poor country instead of being beneficial to its people and economy. Every year the rivers carry enormous amounts of flood waters to Bangladesh. The coastal regions face continuous dangers of Cyclones and Typhoons. These tend to flood the coastal areas damaging crops and potable water sources. With so much water everywhere, no one would believe, that the poor citizens of this country, face drinking water shortages round the year. To control river flood waters, man made water ponds are traditionally built everywhere in this country. Whenever rivers are flooded, these ponds absorb the extra water.
Since last few years, it has been found that the people who drink this pond water tend to get sick and suffer from strange diseases. Symptoms include violent stomach pains and vomiting, diarrhea, convulsions and cramps. A large dose can kill outright, Continuous long term use can lead to cancer of the bladder, kidney, lung or skin. In some cases symptoms appear, in the form of skin lesions. The symptoms clearly showed that the pond water was contaminated. An detailed chemical analysis was carried out and the results explained the wide spread diseases. The pond water had much higher percentage of element Arsenic than the safe level of 50 micrograms per liter. This analysis proved that the poor people of Bangladesh were slowly being poisoned.
This poisoning has become so wide spread now, that out of the population of 140 million, 25 millions are in direct danger zone. In the history of the world, this is the first time when such huge mass of humanity is in danger of getting poisoned.
Scientists trying to find out the reason of this presence of Arsenic in pond water, have found out the real reason only now. Up to year 1970, Bangladeshi farmers and villagers have been drinking this pond water. A survey by UNESCO and WHO found that these ponds were contaminated with microorganisms, which spread permanent epidemics of diarrhea and cholera. It was suggested that the people should not drink contaminated pond water and should drink sub soil water pumped out from bore wells. UNESCO and WHO again decided to dig millions of well throughout the country to provide safe drinking water to at least 80% of the people. Eight million such bore wells were dug. The sub soil water being pumped out, now appears to be the real culprit of Arsenic poisoning.
Earth’s crust always contains Arsenic metal up-to level of 2 milligrams per kilogram of crust. This Arsenic can combine with oxygen and other such reactive element to form water soluble Arsenic compounds. Waters of major rivers can carry these compounds in the water and ultimately deposit these along with mud on the river deltas. River systems of Bangladesh have been doing exactly this for millions of years making Bangladesh soil rich in these compounds. These compounds again dissolve in sub soil water and when its is pumped out, the the arsenic salts along with water, flow down to the flood control ponds and contaminate the water. High percentage of contamination in the pond water has been caused by years of sub soil water pumping.
Research is being carried out now to device filters which can filter out the Arsenic contaminations. Meanwhile poor folks from Bangladesh face the threat of getting poisoned as they have no other choice but to drink pond water on daily basis.
19 November 2009