Man made ponds cause Bangla's mass arsenic poisoning

Researchers have pinpointed the source of what is probably the worst mass poisoning in history, according to a study published today.

For nearly three decades scientists have struggled to figure out exactly how arsenic was getting into the drinking water of millions of people in rural Bangladesh.The culprit, says the new study, are tens of thousands of man-made ponds excavated to provide soil for flood protection.

An estimated two million people in Bangladesh suffer from arsenic poisoning, and health experts suspect the toxic, metal-like element has caused and will continue to cause  many deaths as well.

Symptoms include violent stomach pains and vomiting, diarrhoea, convulsions and cramps. A large dose can kill outright, while chronic ingestion of small doses has been linked to a large range of cancers.

It has long been known that the arsenic comes from water drawn from millions of low-tech "tube wells" scattered across the country.Ironically the wells were dug often with the help of international aid agencies to protect villages from unclean and disease-ridden surface water.

Tragically, millions of people continue to knowingly poison themselves for lack of an alternative source of water.