Perspectives on the Environmental Impact of Nanomaterials: What Do We Know Now, and Where Are We Going?

Nanoscience and nanotechnology are rapidly expanding fields that are driving revolutionary advances in all major science and engineering disciplines. To put this in perspective, in the long term it is projected that the scale of these efforts may one day rival what genomics and proteomics have done in recent decades for the biological, medical, and biotechnology disciplines. Nanoscience is based on the fact that the chemical and physical properties of materials change as a function of their physical dimension, and nanotechnology takes advantage of this by applying selected property modifications of this nature to some beneficial endeavor. At the same time, nanoscience is also relevant to the geosciences, in that naturally occurring nanomaterials are ubiquitous in the atmosphere, hydrosphere, pedosphere, and lithosphere. Not surprisingly, natural nanomaterials are thought to be relevant in a diverse range of Earth systems including the biosphere. Therefore, the amount of research concerning environmental, ecological, and biogeochemical impacts of natural and synthetic nanomaterials is rapidly growing, with not only great scientific, but also large economic and political consequences. Our general knowledge of the behavior of nanomaterials, particularly in an environmental context, will be reviewed, and the possible directions of future research pathways will be discussed.