Water is the key element of life ,when the water mixed with slow poision then how dangerious this is ,we can think.Sources: Bangladesh must execute quickly to fight against arsenic contamination in water and food affecting at least 20 million people, a U.N. agency said Monday, decades after a well-meant plan for clean water became a public health disaster.
A recent survey by the Bangladesh Bureau of Statistics and the United Nations children’s fund (UNICEF) showed that 12.6 percent of Bangladesh households, or about 20 million people, still drink water containing arsenic above the government’s recommendation of no more than 50 micrograms per liter.

Arsenic is a naturally occurring chemical poisonous to humans and is known to cause skin lesions and cancers of the bladder, kidney, lungs and skin.

Bangladesh has set a target of supplying safe water for all its people by 2011. A report by environment experts on arsenic contamination was released in Dhaka Monday.

“Urgent action is needed to re-focus the attention of the nation toward an arsenic-safe environment,” said Renata Lok Dessallien, U.N. resident coordinator in Bangladesh.

“Concerted efforts by the government and all stakeholders are necessary to reinvigorate arsenic monitoring and mitigation efforts and conduct comprehensive research on emerging threats.”

Millions of small tube wells were dug across Bangladesh from the late 1970s, with the help of international agencies like UNICEF, as an answer to dirty surface water which caused widespread gastrointestinal diseases.

Organic carbon can trigger the release of arsenic from sediments into groundwater. Studies have recommended against using groundwater in man-made ponds and rice fields.

“We have taken steps to ensure the proper management of surface water, including rainwater conservation,” agriculture minister Matia Chowdhury told reporters
“We will have to augment the use of surface water and simultaneously limit the use of both surface and groundwater to reduce accumulation of arsenic in crops and food sources,” Chowdhury said.

Hundreds of thousands of people in Bangladesh suffer from skin lesions and experts have warned for years that Bangladesh can expect more cases of cancer if its people continue drinking arsenic-contaminated water.

According to the World Health Organization, arsenic-contaminated water directly affects the health of 35 million people in Bangladesh.

Arsenic is widely distributed throughout the earth’s crust and is introduced into water through the dissolution of minerals and ores.

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Day by day, millions of people in Bangladesh drink poisoned water. Wells all over the country tap into shallow aquifers with high concentrations of arsenic. Now researchers report that they’ve figured out the cause of this contamination.

About 30 years ago, international aid agencies and the government of Bangladesh started installing wells throughout the country.

For good reason: The ponds and rivers where people used to get their water also contained sewage–and deadly pathogens.

But in the mid-1990s, other health problems started appearing. Those who drink the well water year after year develop lumps on their hands and feet and greatly increase their risk of cancer, especially lung cancer; epidemiologists say that drinking arsenic-contaminated well water is as bad as smoking.

Not all water in Bangladesh is equally contaminated, so scientists have been working on figuring out why some wells contain more arsenic than others.

Hydrogeologist Charles Harvey of the Massachusetts Institute of Technology in Cambridge and his colleagues focused their investigation near one village outside of Dhaka, the country’s capital. They drilled wells to measure the depth of the ground water and built a computer model of how water moves underground.

Organic carbon in the water is also crucial, because microbes that feed on it release arsenic from the sediment into the water.

So the researchers measured concentrations of organic carbon and many other dissolved materials in the aquifer and in rice fields and ponds.

Based on these data, the organic carbon in the aquifer most likely comes from human made ponds, the team?reports online this week in?Nature Geoscience. Villagers in Bangladesh dig ponds when they build a house; they pile up the clay to elevate the house above floodwaters, and the pond is used for growing fish and bathing. Rice paddies, on the other hand, don’t seem to leak as much water straight down, Harvey says.

The new model probably won’t apply to all of Southeast Asia, says hydrogeochemist Shawn Benner of Boise State University in Idaho; it’s an intensive look at one site. But he says the study takes a big step forward in linking groundwater flow to the biogeochemistry that leads to the release of arsenic. Even if the study can only show where it would be safe to sink a well in that one village, that’s a big advance, he says.

At rest, biogeochemist Andy Meharg of the University of Aberdeen in the United Kingdom is skeptical that surface water like that from the ponds is a major source of carbon. Other studies have found that arsenic is often buried in the sediment along with ancient organic carbon, and Meharg points out that arsenic levels can be high in places with little or no human activity, such as mangroves.

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