Scientists have developed a water treatment system that they say is a powerful but simple way to save lives.Four grams of chemicals can treat ten liters of dirty water for a low cost, about ten cents.

Experts say infections from dirty water kill several thousand children in developing countries every day.

The Procter and Gamble company has been developing the "PUR Purifier of Water" system since nineteen ninety-five.The company has been working with the United States Centers for Disease Control and Prevention.

C.D.C. researchers tested it in Guatemala, Pakistan and Kenya.Procter and Gamble researcher Greg Allgood says cases of diarrhea in those studies fell by about fifty percent.

Researchers from Johns Hopkins University in Maryland tested the system at a refugee camp in Liberia.Mister Allgood says that study found a reduction of more than ninety percent.

Use of the system is being expanded worldwide.Findings were described last week at an American Chemical Society meeting.

A small container holds the d safe to drink twenty minutes later.

The treatment contains bleach to kill disease-causing organisms.It also contains ferric sulfate which dirt and other particles stick to.Mister Allgood says the chemicals can remove lead and other dangerous metals and even agricultural poisons like D.D.T.

Mister Allgood heads the Children's Safe Drinking Water program at Procter and Gamble.He says about forty million packets of the treatment have been given to countries for free.They have been used in emergencies and in areas with limited supplies of clean water.

Clean water is a limited resource in many parts of the world.Delegates from about one hundred thirty nations attended the Fourth World Water Forum last month in Mexico City.Scientists, policy experts and others discussed ways to provide clean water to the world's poor.Organizers say more than twenty percent of the world population lacks clean drinking water.

The final declaration did not go so far as to declare water a human right.But it did say that governments, not private companies, must take the lead in improving the public's ability to have clean water.

This VOA Special English Development Report was written by Jill Moss.I'm Steve Ember.