Science learns from tradition

A SCIENTIST employed with the Girijan Cooperative Corporation Ltd in Visakhapatnam, Y Durga Prasad, has isolated the world's first biological substance, which can bind with about 18 toxic metals, many of them found in industrial wastes.

Significantly, the substance, found in the seeds of a nut (Strychnos potatorum) traditionally used by Andhra tribals to clean water, is available in plenty for largescale use. Says C E Furlong, a geneticist at the University of Washington in Seattle, "Though similar substances (called bioflocculants) are known to humans, they cannot be produced in quantities large enough to be of any practical use. So, this is a very important discovery."

Proteins present in the bioflocculant enable it to bind with such metals as uranium, thorium, silver, gold, copper, iron, lead, cobalt, nickel, manganese, cadmium and barium.

"Its ability to bind with radioactive uranium and thorium makes it a potential broom for cleaning up radioactive wastes, although it is too early right now to say anything definite," says K Mahadev Rao of the International Atomic Energy Agency. Polluting industries and mining are two other potential beneficiaries of this discovery.