UN Promoting Low-Tech Procedure To Clean Family Drinking Water

Updated 11:31 PM ET March 21, 2001

By ERICA BULMAN, Associated Press Writer

GENEVA (AP) - A do-it-yourself technique of disinfecting water with sunlight and soft-drink bottles could save hundreds of thousands of lives a year, the World Health Organization said Thursday.

In a campaign to reduce deaths from unhealthy water in developing countries, the U.N. health agency is promoting a nearly cost-free process

called Solar Water Disinfection, or SODIS. Requiring only sunlight, empty plastic soft-drink bottles and a black surface, it costs almost nothing, said Martin Wegelin, a researcher at the Swiss Institute for Environmental Science and Technology.

The process is simple: Transparent bottles are filled with water and placed horizontally on a flat surface for about five hours. The heat and ultraviolet rays of the sun kill illness-causing microorganisms in polluted water.

"Some 2.5 million people die from drinking unsafe water every year," said WHO Director of the department of Health and Environment Richard Helmer. "They are unnecessary deaths since this method could provide them with safe drinking water. This is a highly reliable method that has been proven to work."

The method is even more effective when the bottom half of the bottle is painted black or placed on a black sheet of corrugated iron or plastic, which absorbs more heat and kills more pathogens.

The simple process kills most microorganisms, but not all of them, and should only be used in very hot countries where the sunlight is intense, WHO officials said.

More than one billion people drink unsafe water, the agency said in a report to mark World Water Day. A total of 3.4 million people, mostly children, die every year from water-related diseases from drinking, swimming in or washing clothes in polluted water. Diseases include malaria, diarrhea and guinea worm.

WHO urged the use of SODIS, chlorination and better hygiene as immediate means of improving water quality in developing countries. It said chlorination is another simple method that costs just a few cents a day.

"Even in conditions of very poor sanitation and hygiene, where people are collecting whatever water is available for their household supply, if the water is chlorinated (it) is improved," said Mark Sobsey, professor of environmental microbiology at the University of North Carolina in Chapel Hill.

WHO said chlorine could be added to both home and city reservoirs and was essential in refugee camps.

In a related development, an international water expert warned Wednesday that life threatening shortages of clean water in developing countries will double in the next 10 years if no action is taken to reverse the trend.

One in three people in the world's poorer nations is suffering from a clean water shortage and the problem is increasing globally because of mismanagement and population growth, said Datius Rutashobya, president of the World Meteorological Organization Commission for Hydrology.

"Water is the most important natural resource and also the most threatened," Rutashobya said at a news briefing ini Dar Es Salaam, Tanzania. "2010 will be the peak of the clean water shortage if no intervention is taken."