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Water Shortages Continue to Threaten the World’s Growing Population

April 20th, 2010 at 06:13am Under Development Report

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Scientists are working on a new way to turn sea water into drinking water.
This is the VOA Special English Development Report.

The lack of clean drinking water is a major problem worldwide. The World Health Organization says more than one billion people live in areas where renewable water resources are not available. The problem is especially serious in Asia and the Pacific. A United Nations report says water availability in that area is the second lowest in the world, after Africa.

Nearly seven hundred thousand people in Asia and the Pacific lack safe drinking water. The U.N. report notes that the world’s poorest countries are also the ones that use the most water for agriculture. Agriculture uses about eighty percent of the water in the Asia-Pacific area. There has also been an increase in water used for industry. China and India more than tripled their industrial water use between nineteen ninety-two and two thousand two.

The lack of clean drinking water around the world forces millions of people to drink unsafe water. This leads to an increase in diseases like diarrhea, the second leading cause of death in children under five. Floods, droughts, pollution and climate change have created even more problems.

The Millennium Development Goals for two thousand fifteen call for a fifty percent decrease in the number of people without safe drinking water and basic sanitation.

Scientists, governments and aid organizations around the world are increasing their efforts to meet these goals. Still the U.N. says there is much work to be done. During its yearly World Water Day observance last month it called on the international community to work together to solve the water crisis. Researchers at the Massachusetts Institute of Technology are doing just that.

The American and South Korean researchers are investigating a new technology for turning sea water into drinking water. The new technology is called ion concentration polarization. The process uses electricity to help separate electrically charged salt particles from water to make it drinkable.

The researchers tested their desalination process on a computer chip the size of a postage stamp. The chip removed ninety-nine percent of the salt and other harmful substances from water samples. So far the method purifies only small amounts of water. But the researchers say it may someday be available as a personal water purification product.

And that’s the VOA Special English Development Report, written by June Simms. I’m Steve Ember.

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Working With Clay: A How-to Guide

December 23rd, 2009 at 03:51am Under VOA

This is the VOA Special English Development Report.

Clay

Clay is found almost everywhere in the world. It is formed by the action of wind and water on rocks over thousands of years. The rocks change in both chemical and physical ways. Chemically, elements like potassium and aluminum are added and taken away. Physically, the rocks break down into smaller and smaller pieces. After a long time, some of the rock changes to clay.

Clay is important because it is used around the world to make containers of all kinds. Potters add water to soften the clay. This makes it easier to form into shapes by hand or by machine. Then it is fired in an extremely hot stove. The result is a container with a hard surface that will last for many years.

In many countries, clay was formed from volcanoes. This kind of clay usually contains many minerals. So the fires to make containers from volcanic clay must be hotter than those used for non-volcanic clay. The fires may be as hot as one thousand four hundred degrees Celsius.

It is also important to dry the clay containers slowly. This means that the highest temperature should not be reached too fast.

You can add materials to clay to gain desired results. For example, you can add sand to prevent tiny breaks or lines from forming in the finished product. But you should not use sand from the coasts of oceans. Instead, you should use sand from rivers or from other areas of land that are not near the sea.

You can usually find good clay in low areas of islands or land, especially if volcanoes helped form the land. Clay often exists in fields covered with some water. The clay will be found about one meter below the ground. River banks often also have clay about one meter or less under the surface.

You can recognize clay because it is very shiny when it is wet. You can also perform a test. Take some of the material and add enough water to it to make it seem like you are making bread. Then press it in your hand until it is about the size of an egg. It is probably clay if it holds together instead of falling apart when you stop pressing.

And that’s the VOA Special English Development Report, written by Gary Garriott. Guides to working with clay and other materials can be found on the EnterpriseWorks/VITA list of publications. These publications can be ordered for a charge. The list is available at enterpriseworks.org. Transcripts, MP3 and archives of our reports are at voaspecialenglish.com. I’m Chris Cruise.

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