Sufficiency and toxicity limits of metallic oxide nanoparticles in the biosphere

Abstract Metal oxide nanoparticles (MONPs) with an inorganic core composed of a metallic element bonded to oxide (O2 −) anions have been widely used in fertilizers, water treatment, health, cosmetics, electronics, food packaging, and even food products. The production, usage, and disposal of MONPs-containing products are potential routes for environmental exposure into aquatic and terrestrial compartments where the MONPs are subjected to various dynamic processes such as physical, chemical, and biological transformations. These transformation pathways can have strong implications on fate, transport, persistence, bioavailability, and toxicity. The discipline of “nanotoxicology” has developed to study the interactions of NPs with biological systems, toxicity based on NPs’ properties, and levels related to environmental health. This chapter will contribute to understanding the dynamics, interactions, and toxicity perspectives, and help manufacturers, regulation agencies, environmental engineers, scientists, and students to understand the developments of MONPs, their environmental interactions, and potential toxicity limits in commercial products.