Source and pathway of silver nanoparticles to the environment

Abstract

The production and use of silver nanoparticles (AgNPs) in industrial and commercial products increased significantly in recent years. During the production, manufacturing, use and disposal of AgNP containing products, AgNPs would be released into the environment inevitably. Moreover, AgNPs could also be naturally occurred in the environment through biological and chemical reduction processes. In recent years, various chemical and biological pathways, including reduction of Ag+ by natural organic matters, plants and microorganisms, and generation of AgNPs from macroscale elemental silver objects through dissolution and reduction, were demonstrated for the occurrence of naturally occurred AgNPs. In this chapter, we introduce the occurrences of natural AgNPs in the environments and their possible formation pathways and mechanisms, and discuss the anthropogenic pathways for intentionally and unintentionally produced AgNPs and their release into the environment.