Now is the Time to Take Heed of Nanosafety

  Carlo U. Segre, Ph.D., Director
  Professor of Physics and Associate Dean for Special Projects
  Graduate College
  Illinois Institute of Technology

The majority of today's commercial applications of nanotechnology make use of particles on the sub-100 nanometer scale. This is primarily because scientists and engineers know how to prepare such small particles in large quantities using well-understood chemical techniques.

Because nanoparticles are so small, they have large surface-to-volume ratios, which give rise to their novel physical and chemical properties. These often include enhanced chemical reactivity at the nanoparticle surface.

Materials from carbon nanotubes to nanoparticles of titania and silica are finding their way into products and laboratories around the world. Consequently, one of the major challenges for nanotechnology researchers, as well as for industries hoping to commercialize these materials, is to understand the health and safety consequences of preparing, working with, and using nanoparticles.

In starting to address this challenge, it is useful to compare the scale of these man-made particles with two natural dimensions. A human hair is 1,000 times bigger than a 100-nanometer particle, while many viruses are approximately the size of the typical nanoparticle. The same properties that give nanoparticles their physical and chemical enhancements may also have unintended consequences when brought into contact with the human organism. A material that is perfectly safe to handle in bulk (meaning large dimensions) form may easily penetrate the skin in nanoparticle form or become airborne and enter the body through the lungs. The reactivity of the high surface area may interact with biological systems in unknown ways.

If the nanotechnology community does not take these potential health risks seriously, it is conceivable that research and development of nanotechnologies will be seriously delayed by negative public opinion. One recent high-profile case in Germany has been publicized by articles in The Washington Post, Chemical & Engineering News, and a number of other media outlets. A cleaning product alleged to contain nanoparticles delivered in aerosol form reportedly resulted in breathing problems and pulmonary edema in a few cases. While the nanoparticles have not been identified as the cause, they are the headline.

Are these issues unique to the nanotechnology field? No, but the fact that the materials we work with on the nanoscale are well known and more or less benign in bulk form can lead to a false sense of security in the laboratory or manufacturing plant. The good news is that there are a number of research studies in progress to assess the effects of nanoparticles on human health, and there will -- no doubt soon -- be guidelines from the National Institute on Occupational Safety and Health (NIOSH). As scientists and engineers, we have a responsibility to understand the risks and ensure that nanotechnology enterprises are socially responsible and well accepted in the public eye.

Carlo Segre is an Associate Dean in the Graduate College and a professor of physics in the Biological, Chemical, and Physical Sciences Department at Illinois Institute of Technology. He also serves on the Advisory Panel of IIT's Center on Nanotechnology and Society.