Discoverer of arsenic in Bengal’s water supply speaks out

Indian analytical chemist Dipankar Chakraborti of Jadvapur University, Kolkata was born and raised in one of West Bengal’s many small villages on the delta plains of the Ganges. Paying a visit to a friend’s village in 1988, he found people bearing visible symptoms of chronic arsenic poisoning, which had not been diagnosed before. Analysing samples of well water, Chakraborti found extremely high levels of the poisonous element. For years he was reviled by government agencies who paid no heed to his discovery, calling him a ‘panic monger’ – when more recently showing that Bihar and Assam had similar problems he received death threats. Almost single-handed he campaigned for attention to the undoubted problem, until in the mid 1990s it became clear that arsenic in drinking water from recently sunk wells was a plague of biblical proportions across low-lying West Bengal and neighbouring Bangladesh.

Massive funding, both for establishing the extent and distribution of the contamination and for installing means of removing arsenic from well water, flowed form a host of international donors and agencies. To the outside world it has seemed that the tragedy was being remedied by hugely qualified teams of international scientists, and would eventually be held in check. As revealed in a recent interview (Pearce, F & Chakraborti, D. 2006. Drinking at the west’s toxic well. New Scientist, 1 April 2006 issue, p. 48-49), Chakraborti believes that intervention at national and international levels is doing far less than claimed, even exacerbating the problem by pouring in remedial filtration units without teaching villagers to maintain them. Locals’ are encouraged to trust the remedies, yet continue to drink highly contaminated water once the units clog with silts.

Timely review of nuclear waste disposal

The grand old man of biogeochemistry and the Gaia hypothesis, James Lovelock, seems to have lost patience with life’s ability – and that of alternative energy resources – to keep the Earth system in balance. His view that global warming is past the point of no return as regards ‘green’ remedies has been widely publicised in recent months: he has come out in favour of an increase in the contribution of energy by nuclear reactors. He may have fallen out with many environmentalists, but may also have become an ally of politicians who are looking to nuclear power as a way of maintaining ‘business as usual’ yet putting their money where their mouths are, as regards reducing carbon emissions.  Nuclear power may yet have a resurgence, but that would pose again the thorny problem of secure disposal of radioactive wastes. Sweden supplies almost 50% of its electricity using eleven nuclear power stations: the highest number per capita anywhere, despite the country’s otherwise ‘green’ outlook. Should nuclear power rise rapidly elsewhere, then Sweden’s approach to waste disposal may well become a model to follow.  What that system is summarised in a recent issue of New Scientist (Nielsen, R.H 2006. Final resting place. New Scientist, 4 March 2006, p. 38-41). Sweden has discovered quite a challenge at its experimental nuclear-waste disposal facility, even though most of the country’s rocks are hard and crystalline, and therefore seemingly ideal for disposal sterilised from the outside world. Despite the common view that crystalline basement is totally impermeable, in reality it is not. Water will be present in any rocks used to cache waste, unless they are beneath almost totally arid deserts, of which only the USA among developed countries has one. It is also becoming increasingly clear that even at great depths, extremophile organisms infest the rock. Among the most common are those that use the reduction of sulfate to sulfide ions as a metabolic energy source: they produce sulphuric acid. That seems a considerable risk to the integrity of whatever form the waste is stored in. The response of the Swedish researchers has been to look for lateral solutions that either kill off the bacteria using clay packing, or exploit the potentially preservative effects of others.

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