"The best of all things is water" -Pindar 460 B. C. The provision of secure drinking water for its citizens is an aim of every government, and is a priority item to all the NATO and CP countries. The quantity of water in most of these countries is usually adequate, but the quality in many cases is not. With the development of new analytical methods, one suddenly finds new substances of human origin in drinking water. Also, new microorganisms and their toxins pass through the conventional treatment plants to show up in the finished water. What aU of this means to public health is not quite...