World Facing Arsenic Timebomb

[Guest guest]

World facing 'arsenic timebomb'

By Richard Black

Environment correspondent, BBC News website

 

 

 

About 50 million people are affected in Bangladesh

About 140 million people, mainly in developing countries, are being

poisoned by arsenic in their drinking water, researchers believe.

 

Speaking at the Royal Geographical Society (RGS) annual meeting in

London, scientists said this will lead to higher rates of cancer in

the future.

 

South and East Asia account for more than half of the known cases

globally.

 

Eating large amounts of rice grown in affected areas could also be a

health risk, scientists said.

 

" It's a global problem, present in 70 countries, probably more, " said

Peter Ravenscroft, a research associate in geography with Cambridge

University.

 

" If you work on drinking water standards used in Europe and North

America, then you see that about 140 million people around the world

are above those levels and at risk. "

 

Testing time

 

Arsenic consumption leads to higher rates of some cancers, including

tumours of the lung, bladder and skin, and other lung conditions.

Some of these effects show up decades after the first exposure.

 

I don't know of one government agency which has given this the

priority it deserves

 

Allan Smith

" In the long term, one in every 10 people with high concentrations of

arsenic in their water will die from it, " observed Allan Smith from

the University of California at Berkeley.

 

" This is the highest known increase in mortality from any

environmental exposure. "

 

The international response, he said, is not what the scale of the

problem merits.

 

" I don't know of one government agency which has given this the

priority it deserves, " he commented.

 

The first signs that arsenic-contaminated water might be a major

health issue emerged in the 1980s, with the documentation of poisoned

communities in Bangladesh and the Indian state of West Bengal.

 

 

Rice plants absorb arsenic from the soil as they grow

In order to avoid drinking surface water, which can be contaminated

with bacteria causing diarrhoea and other diseases, aid agencies had

been promoting the digging of wells, not suspecting that well water

would emerge with elevated levels of arsenic.

 

The metal is present naturally in soil, and leaches into groundwater,

with bacteria thought to play a role.

 

Since then, large-scale contamination has been found in other Asian

countries such as China, Cambodia and Vietnam, in South America and

Africa.

 

It is less of a problem in North America and Europe where most water

is provided by utilities. However, some private wells in the UK may

not be tested and could present a problem, Mr Ravenscroft said.

 

Problems abroad

 

Once the threat has been identified, there are remedies, such as as

digging deeper wells, purification, and identifying safe surface

water supplies.

 

As a matter of priority, scientists at the RGS meeting said,

governments should test all wells in order to assess the threat to

communities.

 

" Africa, for example, is probably affected less than other

continents, but so little is known that we would recommend widespread

testing, " said Peter Ravenscroft.

 

His Cambridge team has developed computer models aimed at predicting

which regions might have the highest risks, taking into account

factors such as geology and climate.

 

 

Arsenic contamination can be a problem in parts of the US

" We have assessments of the Ganges and Brahmaputra river basins, for

example, and then we look for similar basins elsewhere.

 

" There are similar areas in Indonesia and the Philippines, and very

little evidence of tests; yet where there has been some testing, in

(the Indonesian province of) Aceh for example, signs of arsenic

turned up. "

 

Asian countries use water for agriculture as well as drinking, and

this too can be a source of arsenic poisoning.

 

Rice is usually grown in paddy fields, often flooded with water from

the same wells. Arsenic is drawn up into the grains which are used

for food.

 

Andrew Meharg from Aberdeen University has shown that arsenic

transfers from soil to rice about 10 times more efficiently than to

other grain crops.

 

This is clearly a problem in countries such as Bangladesh where rice

is the staple food, and Professor Meharg believes it could be an

issue even in the UK among communities which eat rice frequently.

 

" The average (British) person eats about 10g to 16g of rice per day,

but members of the UK Bangladeshi community for example might eat

300g per day, " he said.

 

The UK's Food Standards Agency is currently assessing whether this

level of consumption carries any risk.