Tests performed by Dr. Friede at Villanova University showed that in swimming pool water containing ammonia (this is a typical swimming pool condition due to perspiration and urine), silver responded much faster than chlorine. Eighty minutes was required for a virtually complete kill of Pseudomonas Aeruginosa bacteria using chlorine, versus only 20 minutes using silver. Likewise, silver took only one minute, for a 70 per cent kill compared to 10 minutes for chlorine.
Extensive bactericidal studies conducted at the British Centre for Applied Microbiology and Research, Salisbury England confirm silver’s effectiveness against bacteria and viruses and that silver/copper systems will inactivate Legionella pneumophila, among many other organisms.
Excerpts from the University of Arizona Department of Microbiology and Immunology Lab Reports have also concluded this effectiveness.
During the 1930’s and 1940’s, there was considerable interest in the use of silver for water disinfection in the United States, Russia and Poland. Investigators recognized the bactericidal effectiveness of silver but little was done to develop the process because of the availability and low cost of chlorine.
Silver-based chlorine-free water purification systems have been used effectively in Europe for many years. European labs have proven it to be a harmless, simple and effective means of killing all vegetative germs present in drinking water, especially those causing diseases such as typhus, paratyphus, dysentery, colibacillosis, cholera and also the viruses causing influenza and mumps.
The U.S. Environmental Protection Agency announced January 1991 that it has removed silver from the U.S. Primary Drinking Water Standard List of Contaminants. Prior the EPA limited the amount of silver in drinking water to 50 ppb. In swimming pools/spas, less than this is used as a bactericide. The EPA decision will result in an important increase in the use of silver as an alternative means of purifying water throughout the United States.
NASA has even taken to an electrolytic water sterilizer that was developed for control or microbial contamination in manned spacecrafts. Individual sterilizer cells are self-contained and require no external power or control.