Clean drinking water is an essential, universal human need — and millions of water purifiers are sold each year. Many of these filters make use of silver-impregnated activated carbon to remove contaminants and control bacterial growth, just as they do in home pipe systems and community water systems.
Silver has been used in water treatment for centuries. In the fight against harmful microorganisms such as Legionnaires’ disease and E. coli, silver is a natural alternative to harsh artificial chemicals. Silver is resistant to corrosion and oxidation, meaning it can purify water without leaving harmful byproducts. Silver is widely used in water filtration and purification processes for swimming pools, spas, drinking water treatments, and pipe systems, helping to eliminate harmful microorganisms and bacterial growth.
In these filtration systems, combining silver and copper may allow quantities of chlorine and algae to be reduced while still providing equivalent or better sanitary water quality. Also silver in synergy with copper is effective against pathogens independent of water temperature, therefore it is not necessary to run hot water at very high temperatures, saving energy and reducing the overall carbon footprint. Similarly, silver can be used in home humidifiers and industrial cooling towers to control bacterial growth, as well as at pulp and paper mills as an effective fungicide and biocide.
Silver in Water Disinfection: 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 especially in developing countries.
As the WHO states: “Most metals are “oligodynamic;” this means that “with only a small amount, they can produce an effect.” Metals like silver, copper, mercury, manganese and iron, among others, are all potential water disinfectants. However, of all of these metals, only silver, for several reasons, has been used to some extent to disinfect water for human consumption, and this use dates back to ancient times….. Silver has disinfecting properties only in its colloidal state —when it is in the form of extremely small particles in suspension which, because of their size, are easily charged electrically. In its colloidal form, silver does not eliminate viruses, but is considered highly effective in destroying different types of bacteria. Silver’s disinfection mechanism acts by inactivating bacteria and mould cell enzymes that need oxygen for their metabolism.”
Source: WATER DISINFECTION, Regional Office of the World Health Organization 2003: https://apps.who.int/iris/bitstream/handle/10665/68905/a85637.pdf?sequence=1
Silver in Hospital Water: Many modern hospitals filter hot water through copper-silver filters to defeat MRSA and legionella infections. Ionised silver has proven to effectively control pathogens in water systems due to its superior residual effect and potential to remove biofilms. Biofilms are communities of microorganisms that attach to each other and to surfaces, for example by bacterial adherence. Biofilms can be problematic in certain places, for example inside pipes.
A 2018 study published in the American Journal of Infection Control carried out in a newly built health care facility in the United Kingdom, demonstrated that it is possible to control Legionella pneumophila independent of temperature when copper and silver ionization is introduced into a new building in conjunction with an appropriately managed water system. Hospital-acquired Legionnaires’ disease is associated with the presence of Legionella pneumophila in hospital water systems. The mortality rate for patients who develop Legionnaires’ disease while in a health care facility is close to 50%.
See the study here: https://www.sciencedirect.com/science/article/pii/S0196655318311490
Silver in Space Water: Silver has been used as a water disinfecting agent, even in space in the drinking water supplies of the Russian Mir orbital station and the International Space Station. In the 1960s, NASA’s Manned Space Center conducted a research programme to develop a small, lightweight water purifier for the Apollo spacecraft that would require minimal power and would not need to be monitored around-the-clock by astronauts in orbit. The 9-ounce purifier, slightly larger than a cigarette pack and completely chlorine-free, dispensed silver ions into the spacecraft’s water supply to successfully kill off bacteria. A NASA Technical Brief released around the time of the research reported that the silver ions did not “impart an unpleasant taste to the water.” In 2011, NASA tested silver ions as a means of disinfecting potable water they found that 0.4mg/L of silver was an effective biocide for water purification in space. They also found that ionic silver reduced bacterial growth on metal surfaces.
“Numerous independent laboratory tests from NASA, health departments, and universities, and many years of field testing have confirmed the exceptional sanitizing ability of copper/silver ionization. Studies further show that using a combination of copper and silver can be effective against E. coli, Pseudomonas, Legionella Pneumophila (Legionnaires’ disease), Staphylococcus, Streptococcus, Salmonella, and other pathogens—some of which have proven to be resilient even to high levels of chlorine.” NASA https://spinoff.nasa.gov/Spinoff2004/er_1.html