Rice - arsenic in Bangladesh

In Bangladesh, West Bengal (India) and some other areas, most drinking-water used to be collected from open dug wells and ponds. Much of this water was contaminated and transmitted diseases such as diarrhoea, dysentery, typhoid, cholera and hepatitis. Programmes to provide 'safe' drinking-water over the past 30 years have helped to control these diseases, but in some areas they have had the disturbing side-effect of exposing the population to another health problem - arsenic.

Bangladesh tubewells

Shallow wells, known as tubewells, are now commonly used in Bangladesh to avoid the region's surface water, much of which contains bacteria that can cause waterborne diseases. In the 1970s, international aid organizations dug millions of tubewells, and the program was basically successful in providing bacteria-free water. But scientists soon found that the tubewells were reaching groundwater containing naturally high levels of arsenic.
Photo of a flooded rice paddy
Rice irrigation in Bangladesh

Farmers in Bangladesh also use tubewells for irrigation so that rice can be grown during all six months of the dry season. The arsenic that is building up in the soil from irrigation is now contaminating rice grains.

Finding solutions

Within Bangladesh, a number of initiatives have been set up to investigate water quality testing and control with a view to supplying arsenic-free drinking-water. One of the positive outcomes has been the testing of new types of treatment technologies. Only a few proven sustainable options are available to provide safe drinking and irrigation water in Bangladesh. These include obtaining low-arsenic groundwater through accessing safe shallow groundwater or deeper aquifers (greater than 200 m), rain water harvesting, pond-sand-filtration, household chemical treatment, and piped water supply from safe or treated sources.

There is also hope that certain rice strains can be developed to accumulate less arsenic than the varieties of rice currently in use. These are high iron varieties that mop up excess arsenic by an interaction between fungi on the roots of the rice and iron within them. This reduces the amount of arsenic which collects in the grain, which is the part that people eat.