electrolytically-dissolved silver has been used as a water disinfecting agent, for example, the drinking water supplies of the russian mir orbital station and the international space station. many modern hospitals filter hot water through copper-silver filters to defeat mrsa and legionella infections. the world health organization includes silver in a colloidal state produced by electrolysis of silver electrodes in water, and colloidal silver in water filters as two of a number of water disinfection methods specified to provide safe drinking water in developing countries. along these lines, a ceramic filtration system coated with silver particles has been created by ron rivera of potters for peace and used in developing countries for water disinfection (in this application the silver inhibits microbial growth on the filter substrate, to prevent clogging, and does not directly disinfect the filtered water).