Nanoparticles in the Environment: Occurrence, Distribution, and Risks

Rapid advances in nanotechnology in recent years have raised concern about the occurrence, distribution, fate, and transport of nanoparticles in the environment. Sources of nanoparticles in the environment include their widespread use in a variety of engineering operations, biomedical applications, consumer goods, food and drug delivery system, and so forth. Because they can be released into the environment either as a waste product or as a byproduct of some engineered processes or applications, nanoparticles or nanoscale materials are increasingly detected in various environmental matrices. By their very nature, nanoparticles are active at molecular levels, and there is a concern that their occurrence in the environment and unintended exposure may pose an adverse risk to human health and ecology. Because of the nature of recent nanotechnology-based applications, our understanding of nanoparticle behavior in the environment is limited. The objective of this literature review is to provide a measure of understanding and to document the state of knowledge on the environmental occurrence, distribution, fate, and risk of nanoparticles. This review covers a wide range of published studies that illustrate the state of understanding about the behavior of nanoparticles in various environmental matrices such as air, soil, water, and wastewater. A brief review of the evolving regulatory framework to deal with the occurrence of nanoparticles is also included(C) 2014 American Society of Civil Engineers.