Nanotechnology has found its way into many products. Indeed, companies have claimed that more than 300 products are nanobased, according to a database maintained by the Woodrow Wilson International Center , in Washington, D.C. In some of these products, such as skin creams and toothpastes, nanoparticles are in contact with a person’s body, so many experts are concerned that the novel properties of nanoparticles could cause health problems.
The Wilson Center has been calling for more research into the potential toxicity of nanoparticles, and eventually for regulation of the new materials. In this week’s issue of the journal Nature , Andrew Maynard, the science advisor for the center’s nanotechnology project, along with 13 leading experts in nanotoxicity research, propose five challenges that they hope will help direct research.
Technology Review asked Maynard about the dangers of nanomaterials.
Technology Review What evidence is there that nanotechnology requires special attention?
Andrew Maynard: Individual experiments have indicated that if you develop materials with a nanostructure, they do behave differently in the body and in the environment.
We know from animal studies that very, very fine particles, particles with high surface area, lead to a greater inflammatory response than the same amount of larger particles. We also know that they can enter the lining of the lungs and get through to the blood and enter other organs. There is some evidence that nanoparticles can move into the brain along the olfactory nerve, so this is completely circumventing the blood-brain barrier.
TR If we already know nanomaterials can potentially be dangerous, why not regulate them now? Why not require companies to test their products to prove they are safe?
AM: They could do that, but then the question is, What are the appropriate tests? The last thing companies want to do is run conventional tests and bring a product to market, and then discover that they’ve missed something, or regulations change, and so they should have done something else.
TR So we need more research. What is making getting definitive results so difficult?
AM: There really isn’t any consensus on how you go about evaluating the risks associated with carbon nanotubes yet. In cell cultures, you have to have some idea what kind of response you’re looking for. We already know in some studies that the lungs see carbon nanotubes almost as biological materials–they don’t see it as a foreign material. But then because of that, they start building up layers of collagen and cells around these nanotubes. They almost see them as a framework for building tissue on. Now, that actually may be a good thing in parts of the body, but in the lungs you end up using up the air space. But without that information, you wouldn’t necessarily know what were the appropriate cell tests to do in the first place.
TR So given the need for more research, who’s going to fund it?
AM: Clearly there is joint responsibility between government and industry. There’s a fairly strong argument for governments around the world to invest in research on the basics: what makes these harmful, what makes them safe? But then industry clearly has a role to play, because if they’re commercializing these technologies, they have a responsibility to make sure that they’re safe. So industry has a role in taking the research that’s coming from governments, and then applying it to specific products and technologies.