A review of the antimicrobial action of silver ions and silver nanoparticles recently published in Environmental Health Perspectives emphasizes that use of silver nanoparticles requires some care to minimize environmental risks and improve product efficacy. Silver in various forms is widely used to provide a persistent antimicrobial surface on items ranging from surgical tools to shopping totes.
The review article focuses on research from Rice University designed to improve knowledge of how silver works in its role as an antimicrobial.
The research found that silver nanoparticles are a more effective delivery mechanism for the antimicrobial effects of silver than silver ions derived from such substances as silver nitrate. The research found that it is silver ions that have the antimicrobial effects but nanoparticles can more effectively deliver the ions to the place where they are needed than free ions themselves. Silver nanoparticles have a much smaller antimicrobial effect but are much less easily disrupted by other chemicals in the environment than silver ions.
Silver is an environmental contaminant and the study reinforces that care needs to be taken in any use of silver as a disinfectant to avoid collateral environmental damage.
Future studies could lead to more regulation of use of silver as a disinfectant.
The review article is available at http://ehp.niehs.nih.gov/2012/10/understanding-the-germicidal-effects-of-silver-nanoparticles/