A review on silver nanoparticles-induced ecotoxicity and the underlying toxicity mechanisms

Silver nanoparticles (Ag-NPs) are increasingly being applied in many consumer products due to their unique properties. Widespread use of Ag-NPs leads to an increasing human exposure to Ag-NPs in many different pathways. This review summarized the toxicity mechanisms of Ag-NPs based on various environmentally relevant test species, such as bacteria, cells, plants, aquatic animals and mammals, in both in vitro and in vivo experiments. Nanoparticles were usually exposed to combination chemicals but to single chemicals in the environment and thereby exert combined toxicities to the organisms. Therefore, the joint effects of nanomaterials and their co-existing characteristics were also discussed. The current knowledge gaps and safe product designs of Ag-NPs have been discussed in detail. The limited and existing data implied that understanding the toxicity mechanisms is crucial to the future research development of nanomaterials.