New Hidden Earth: The Importance of Putting Natural, Incidental, and Manufactured Nanoparticles in a Global and Historical Context
Thursday, September 9, 2010
Michael F. Hochella Jr.
Michael F. Hochella, Jr.
Department of Geosciences
Virginia Tech, Blacksburg, Virginia
Abstract: Just over two hundred years ago, William Smith from Oxfordshire, England made singular and brilliant discoveries that eventually allowed him, for the first time by anyone ever, to draw the hidden underside of the Earth’s surface, giving us the first geologic maps and also the first understanding of the structure of the Earth’s interior. Today, we are discovering another basic aspect of Earth that has remained mostly hidden until recently, despite its continuous presence all around us. This is the world of both naturally occurring and human-caused nanoparticles, too large to be studied by methods long used to study atoms and small molecules, and too small to be seen by anything but the most powerful electron microscopes. Nature, from the beginning of Earth-time, has always produced a vast store of these illusive and fascinating particles. Human activities produce more unintentionally, and recently the explosive growth of nanotechnology has been driven by the rapid development of thousands of different kinds of synthetic nanomaterials, several with remarkable properties having one to practically enumerable commercial applications.
An understanding of the grand importance of the interactions of nanoparticles with living things, as well as their general ecological impact in a highly complex Earth environment, is starting to become established. All of this has direct bearing on new fields called nanotoxicology and nanoecotoxicology, defined as the safety evaluation of nanostructures through a knowledge of the mechanisms and biokinetics of nanomaterials causing adverse effects to humans and the environment. The enormous impact of asbestos-human lung interactions provides some idea of the scope and importance of this new field. At the same time, it is critical to put all of this in context, that is, within the understanding of the natural Earth system. Measuring and understanding nanoparticle origin (biotic or abiotic, natural or anthropogenic), geographic distribution, relevant nanochemistry, and overall influence and impact within the complex chemical and physical framework of Earth systems are all critical challenges for the future with not only vital scientific, but also large environmental, human health, economic and political consequences.