The chapter discusses the risks associated with manufactured nanomaterials, highlighting the challenges in understanding their health and environmental impacts. It outlines the diverse methods for producing nanomaterials, such as chemical vapor deposition, arc discharge, and controlled pyrolysis, and the various applications in industries like cosmetics, water treatment, and environmental remediation. The text emphasizes the potential for nanomaterials to enter the environment through various pathways, including point and non-point sources, and their potential to affect organisms through exposure and toxicity. It also addresses the need for better understanding of nanomaterials' mobility, bioavailability, and ecological impacts, as well as the importance of responsible production practices to minimize health and environmental risks. The chapter concludes by noting the rapid growth of the nanomaterials industry and the urgent need for comprehensive risk assessments and regulatory measures.The chapter discusses the risks associated with manufactured nanomaterials, highlighting the challenges in understanding their health and environmental impacts. It outlines the diverse methods for producing nanomaterials, such as chemical vapor deposition, arc discharge, and controlled pyrolysis, and the various applications in industries like cosmetics, water treatment, and environmental remediation. The text emphasizes the potential for nanomaterials to enter the environment through various pathways, including point and non-point sources, and their potential to affect organisms through exposure and toxicity. It also addresses the need for better understanding of nanomaterials' mobility, bioavailability, and ecological impacts, as well as the importance of responsible production practices to minimize health and environmental risks. The chapter concludes by noting the rapid growth of the nanomaterials industry and the urgent need for comprehensive risk assessments and regulatory measures.