Sources of silver in the environment

Abstract

Silver is a naturally occurring metal that is extensively utilized in the photographic and imaging industry, as well as in electronics and electrical applications and other lesser uses. It is known to be discharged to the environment from its industrial applications, and this leads to the possibility for exposure to aquatic and terrestrial organisms. Because of great differences in toxicity between silver compounds, the form in which silver enters the environment is important. While the ionic form of silver has been shown to be toxic to a variety of aquatic organisms, forms of silver other than ionic, or free, silver are significantly less toxic. Ionic silver is known to convert to the more innocuous forms as it reacts rapidly with natural chemical ligands in sewer systems, sewage treatment facilities, and the environment. This paper reviews information on the industries that use silver, the quantities they employ, and the forms and amounts of silver that may be discharged from each into the environment.