STERILISED drinking water has been a burning problem in the developing countries since a long time. It has been assessed that water-borne diseases claim nearly five million lives annually in Afro-Asian countries. The situation is further aggravated in the event of natural calamities like cyclone and earthquake. Shortage of chlorinated tablets compound the problem of potable water further. Swiss Federal Institute for Environmental Science and Technology, Duebendorf, has recently developed an innovative, simple method using …showed first 75 words of 481 total…

…showed last 75 words of 481 total…to get it, they don't tend to worry what it contains". Further SODIS can not be employed on a large scale of water. It also requires relatively clear water (turbidity less than 30 NTU) To achieve satisfactory result it is recommended exposure for five hours under bright sunlight or up to 50 per cent cloudy sky, or two consecutive days under 100 per cent cloudy sky. Chief Chemist, King Institute of Preventive Medicine, Chennai brardipasand.com timeindia.com