The people of Bangladesh have endured flood, famine and disease. Now they must contend with a mass outbreak of arsenic poisoning that, according to one expert, makes the Chernobyl disaster “look like a Sunday-school picnic”. The irony is that this catastrophe is the direct result of well-intentioned attempts to provide the nation with safe water for drinking and irrigation.

Up to 75 million Bangladeshis are at risk. A British court will soon be asked to decide whether one organization, the British Geological Survey, can be held accountable for its role in the crisis (see page 556). The case holds the prospect of hundreds — maybe thousands — of victims gaining compensation. But some experts fear that the threat of legal liability may in future deter Western hydrogeologists from working in the developing world.

That would compound the tragedy, because the expertise of Western scientists is still urgently needed. Wells will continue to be sunk across the Ganges delta, and without further research into the causes and extent of arsenic contamination, they may continue to draw from bodies of tainted groundwater.

Western hydrogeologists also have a moral obligation to the people of Bangladesh. Together with government officials and local scientific experts, they must accept collective responsibility for the long delay in recognizing the problem.

When the first wells were sunk in Bangladesh in the 1970s, nobody suspected that arsenic could contaminate groundwater in river-plain sediments. Reports of arsenic poisoning related to wells sunk into such deposits began to emerge from West Bengal, across the Indian border, in 1983. Yet the first major conference on arsenic poisoning in the region and subsequent attention in the international scientific literature did not follow for more than a decade.

Government officials in Bangladesh and West Bengal — keen not to shoulder the burden of yet another public-health crisis in full view of the international community — had a hand in this. Warnings from local public-health experts in the mid-1980s were ignored. But both Western scientists and their colleagues on the Indian subcontinent must ask themselves whether they could not have done more to ensure that news of this public-health disaster emerged more quickly.

By accepting some of the blame, the scientific community may make it easier for local officials to take their share of the responsibility — and allow everyone to work towards preventing further loss of life.