This chapter examines the complex relationship between nanotechnology and its potential effects on environmental systems and human health. It begins with an exploration of environmental fate mechanisms—including the transport, transformation, and persistence of engineered nanomaterials in diverse ecosystems—before progressing to fundamental toxicity principles and the ways in which nanomaterial properties influence biological interactions. Assessment models for predicting and quantifying impacts are evaluated, alongside comprehensive lifecycle analyses that trace nanomaterials from production through disposal. The chapter also investigates containment measures and engineered solutions aimed at mitigating potential risks. Finally, it explores emerging applications of artificial intelligence and Internet of Things technologies for real-time monitoring of nanomaterials in environmental and biological systems. Throughout, the chapter underscores the importance of balancing technological advancement with responsible stewardship of environmental and public health.