Arsenic affecting Bangladesh crops

Food self-sufficiency might no longer be enough

By the BBC's science correspondent Richard Black

Crops in Bangladesh are being contaminated with arsenic from water used for irrigation, according to research by Bangladeshi and Australian scientists.

They found evidence of high concentrations of the poisonous substance in rice and vegetable plants.

Contamination of drinking water affects around 20 million people in Bangladesh and the neighbouring Indian state of West Bengal.

Bangladesh has many health worries

Over a decade ago, scientists in Bangladesh discovered that drinking water drawn from wells was contaminated with arsenic.

The same wells provide the vast majority of the water which farmers use for irrigation.

Now researchers have discovered that the arsenic is being absorbed by several crop plants.

In rice, they have found high levels of arsenic in the stems of plants, though not in the grains.

Massive problem

Root vegetables are also contaminated.

The scientists describe their findings as "preliminary" and stress that many questions remain to be answered.

These include the impact on human health and over what area crops are affected.

Another concern is that arsenic could reduce the yield of rice, even if it does not enter the grains which are used for food.

Even a cup of tea could be unsafe

While this research goes on, the scientists urge farmers to use surface water rather than wells if possible.

The contamination of groundwater in Bangladesh and West Bengal is the biggest mass poisoning in history.

The latest estimates are that around 20m people drink water with dangerously high levels of arsenic.

More than 10,000 people are known to have arsenic-related diseases, but it is thought that many more cases have gone unreported.