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The largest mass poisoning of a population in history is now underway in Bangladesh

It is a terrible public catastrophe, asserts Allan H. Smith, Professor of Epidemiology at the University of California, Berkeley, and a WHO consultant who has investigated arsenicosis in Bangladesh on several trips.
On the occasion of World Water Day 2002 ( WHO has
published its Feature 206:

Geneva, March 2002-The largest mass poisoning of a population in history is now underway in Bangladesh.

It is a terrible public catastrophe, asserts Allan H. Smith, Professor of Epidemiology at the University of California, Berkeley, and a WHO consultant who has investigated arsenicosis in Bangladesh on several trips.

The number of people affected by this arsenic disaster is among the greatest of any disease facing the world today. "By virtue of its sheer size it is pushing the limits of our knowledge and capacity to respond to it," asserts Professor Hans van Ginkel, Rector of the United Nations University in Tokyo.

The crisis has, however, spurred intense research in water de-contamination techniques. How to ensure tens of millions of people arsenic-free drinking water when their water supply comes from wells, many of them rich in arsenic.

How many Bangladeshi are exposed to a high level of arsenic? Estimates vary from a low of 28-35 million to a high of 77 million, more than half the population of the country.

The Bangladeshi are being poisoned by drinking well water, usually without knowing it. Only three decades ago health and development experts, and small local contractors, dug between 7-11 million deep tube wells throughout Bangladesh. The experts encouraged the whole nation to drink well water because it was safe. It was free of the bacteria that caused water-borne diseases such as diarrhoea and other intestinal maladies that have long plagued tropical Bangladesh.

Ironically, the people of Bangladesh exchanged water-borne diseases for arsenicosis. In the 1970s public health specialists and government policy-makers did not think of arsenic. It was only in 1993 that the "clean" well water was discovered to contain dangerous quantities of the poison.

Arsenicosis can cause skin cancer as well as cancers of the bladder, kidney and lung, and diseases of the blood vessels of the legs and feet, and possibly diabetes, high blood pressure and reproductive disorders.

WHO's most recent guideline for a maximum amount of arsenic in drinking water recommends 10 parts per billion (ppb). That was in 1993 when it was lowered to that level from 50 ppb. A new guideline is anticipated in2003. But most water that is drunk in arsenic affected areas in
Bangladesh has substantially higher levels, frequently far above 50 ppb.

Arsenic-contaminated water is not restricted to developing countries. In the western states of the United States of America about 13 million people drink arsenic-tainted water, albeit less contaminated than the well water in Bangladesh. Australia, too, has arsenic-contaminated
water. So do Argentina, Brazil, Chile, Hungary, Mexico, Taiwan (Province of China), Thailand, Viet Nam, and the eastern areas of India in Bengal.

"Unfortunately," says WHO sanitary engineer, Hiroki Hashizume, a Japanese expert on arsenic, "it is virtually impossible, with present measurement techniques, especially in the developing world, to measure quantities below 10 ppb. When drinking water guidelines or national standards are established, careful attention has to be paid to analytical capability, arsenic removal technology, etc., to ensure that the levels are really achieved. Since the principal health gain comes from targeting those most exposed to arsenic poisoning, using an intermediate target of 50 ppb, until a lower target can be achieved, would already improve people's health given Bangladesh's limitations.

"Another unfortunate and complicating fact about arsenic poisoning," Hiroki Hashizume adds, "is that it generally takes from seven to 10 years, sometimes longer, for the disease to be recognized. When it
finally is, it may be too late to treat."

Professor Robert Goyer, who headed a nine-member commission of the US National Academies of Science, says its findings bolster a 1999 study by the Academy that found that men and women who drink every day water with 10 ppb of arsenic have an increased risk of more than 3 in 1000 of
developing bladder or lung cancer during their lifetime. That risk rises to 7 in 1000 at 20 ppb.

Arsenicosis is recognizable from skin color changes, blotches all over the face and body, hyper pigmentation on the chest and upper arms, hard patches on palms and soles of the feet, inability to walk, debilitating pain, watery eyes.

Recently, a woman staggered into a village in Chandpur District where Nasrine R. Karim, the head of a Bangladeshi non-governmental organization, Earth Identity Project, was visiting arsenic-sick

"She was in a pitiful state," recalls Nasrine. " She could barely walk or stand up. Her face and body were covered with dreadful splotches. Her hands and the bottoms of her feet were a solid mass of hard patches, her eyes watery. Her lips and tongue were blue. I had never seen a victim of
arsenicosis in such a ghastly condition."

Nasrine, whose NGO deals with 5,000 villagers who have been drinking the arsenic-tainted water found in 98% of the area's wells, decided to transport Chandrabanu to Dhaka. There she was given vitamins and was well nourished for her severe malnutrition. Nasrine took the woman into
her house for two months.

"During this period she followed the STAR water treatment," Nasrine says. "STAR stands for Stevens Technology for Arsenic Removal. Stevens is an institute in Hoboken, New Jersey, and one of their engineers, an environmental chemist named Xiaoguang Meng, has invented an effective
and inexpensive method for filtering out the arsenic from drinking water for individual households.

"You pour well water into a 20-liter bucket and then empty into it a small packet of powder containing 3.8 grams of an iron sulphate mixture with a small quantity of calcium hypochlorite. You stir with a stick for less than a minute. Then pour the water into three or four inches of sand which serve as a filter. To make sure that no arsenic has slipped through the sand, we throw away this first water. The next batch of water flows into a hole in the bucket through a tube into a second bucket. It is perfectly clean and ready to be drunk.

"In about two months Chandrabanu felt and looked well enough to return to her village. Since then, the splotches on her face and body and the hard patches on her feet have disappeared. Today she is no longer in any pain, and she is walking and working. She has improved tremendously, and yet we thought we couldn't possibly save her life.
For Chandrabanu it is a miraculous cure. For us at the Earth Identity Project it is a remarkable result, full of hope. I don't dare yet to call it a 'cure,' although it has all the signs of one."

Nasrine says that her 5,000 villagers are all using the same water treatment and "responding favorably. The results are, again, very encouraging."

Jamie Bartram, Coordinator of WHO's Water, Sanitation and Health Programme, says "we know that arsenic is rapidly excreted in urine. So, for early or mild cases of arsenicosis no specific treatment other than clean, safe water is required. Nasrine Karim's experience seems to suggest that ceasing to drink arsenic-tained water, combined with the natural excretion of the arsenic in urine, can eliminate arsenicosis.
Any technique that guarantees uncontaminated water, will do the trick. It remains to be seen, however, whether all the possible long-term after-effects of arsenicosis will really have been eliminated. Basically, clean water is the cure."

Considering what approach one should take for curing or preventing arsenic poisoning, Professor Smith of U. Cal. Berkeley, agrees that "the basic treatment is to supply the patient with drinking water that is free from arsenic. This is the first priority. Indeed, in the absence of good evidence for the effectiveness of other treatments, the second priority is to continue providing arsenic-free water, and the third priority is to monitor patients to ensure that they remain unexposed to arsenic."

And is Nasrine Karim's success on a small scale meaningful for the tens of millions of other Bangladeshi who are exposed to arsenic poisoning?
"I think so," she says. "Instead of paying $10 for the buckets and importing the chemical packets from the United States, we could easily manufacture them here in Bangladesh in huge quantities and sell them at a far lower price. To do this we need substantial funding. I'm often told that health funding is available if it's for a good cause. Coping with the arsenic poisoning of millions of women, children and men -'the largest mass poisoning of a population in history' -- is a good cause,is it not?"

Note to journalists:

for more information or interviews please contact :
Jamie Bartram, WHO, Coordinator, Water, Health and Sanitation Unit,
WHO, Geneva.
Telephone (+41 22) 791 3537, E-mail:;

Hiroki Hashizume, Engineer, Water, Sanitation and Health Unit, WHO,
Telephone (+41 22) 791 3726, Email:;

Paul Ress, media consultant, Geneva. Telephone (+41 22) 734.9813,

All WHO Press Releases, Fact Sheets and Features as well as other
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You can view the "beforee and after Chandrabavu pictures by clicking on

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Thursday 21 Mar 2002
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