Part of the show Medicine in the Tropics
For most of us, turning on the tap and drinking a glass of clean water is something that we take for granted, but the WHO estimates that 3 and a half million people, mostly childen in the third world, die each year from diseases caught from contaminated water. Most of these people cannot afford water sterilisation equipment, but a simple answer to this problem may be at hand. Scientists from Newcastle and India have come up with the bright idea (!) of using nothing more than fresh air and sunlight to purify water. They have found that briefly shaking up water in a bottle oxygenates the water. If this oxygenated water is then left in the sun for a few hours the ultraviolet rays in the light break up the oxygen to form 'free-radicals' which kill any microbes in the water that can cause food-poisoning. The researchers are now trying to work out exactly how much sun is needed to clean up water, and whether the same trick will work when the weather is bad, such as during monsoon times, when diseases spread by water are most common.