?With the Emergence of New Nanotechnologies, There Is a Real Need to Monitor Exposure to Humans?

In the Nature paper [1], you list 5 grand challenges for nanotechnology risk research.  What are they?

The five main challenges are to develop instruments to assess exposure to engineered nano-materials in the air and water and we think that that challenge will take three to ten years.  There already exist some instruments for the measurement of ultra-fine particles in the workplace and in the environment, but with the emergence of new nano-technologies we feel that there is a very real need to monitor exposure to humans in the air and within water.  It is important to know that when you start moving away from simpler matrices like air, into water, then into more complex matrices like food, the challenge becomes increasingly difficult. 

The second challenge would be to develop and validate methods to evaluate the toxicity of engineered nano-materials within the next 5 to 15 years.  It’s not entirely clear that the published studies to date use appropriate models of toxicity, or of exposure, for that matter.  So one has to be very careful, and in fact in some cases, even skeptical of the exisiting data; some scientists extrapolate from exposures that occur primarily on skin to toxic effects that are seen after inhalatation.  So it’s very important that as we move forward, we develop models that are appropriate for the likely root of exposure.

Parallel to that, it should take a decade or so to develop models for predicting the potential impact of engineered nano-materials on the environment and human health.  We have very little information on where these materials are likely to end up and what the life cycles of these materials are after their intended use, including their ejection into the environment.  It is going to be very important to understand the potential for air accumulation, bio-magnification, re-entry into the food chain with exposure to humans and livestock and so on.  There’s the real possibility of an adverse impact on aquatic species.  (At this point, it is important to note that I am talking about possibilities not probabilities.)  The whole thrust of this article is that we don’t know [the effects] at present; in order to develop these new materials rationally and safely, we need to know, so that we don’t spend huge amounts of money in cleaning up something that isn’t a problem and that we don’t miss something that could be a potential Trojan horse. 
 
The next challenge would be to develop reverse systems to evaluate impact on the environment and the health impact of engineered nano-materials over their entire life span, which speaks to the life cycle issue.
 
The fifth is more of a grand challenge, in my way of thinking.  Broadly in the field of risk science, we have tools that are sometimes good, but frequently inadequate to properly assess risk to human health and to the environment.  We need to develop these tools.

In a recent interview to Scitizen, Toby Shelley, who wrote a book on nanotechnology, told us that “The Opportunities for Good and Bad Offered by Nanotechnology Demand an International Response”. In your opinion, how should nanotechnology programs be governed and controlled?

Certainly in the United States and in Europe, there are regulatory bodies that will oversee both the use and the abuse of any material.  The Food and Drug Administration, here in the States, attempts to ensure materials that are safe and effective.  With the EPA, [they attempt to ensure] that there is no demonstrable harm to an environment or to people in that environment.  In a sense, this broadly prevents or removes the need for agencies to define what they’re looking at and I think that nano-materials are just another instance of the wide array of technologies that we have developed; there’s a potential for them to be disruptive and we need to be vigilant, but I think that the regulatory agencies need to be adequately resourced so that they can police—in a meaningful fashion—the manufacture, use, and disposal of nano-materials.  The brief answer to that would be that the regulatory agencies need to have adequate resources to monitor properly.

Now what is your plan to address these 5 challenges?

These challenges are so large.  In fact, the paper was written in order to have a broad, but big impact on the field.  A propos your prior question, I think it is going to be very important to pool resources internationally to avoid duplication where possible, because I think we are all dealing with limited resources to go about the very difficult, but pressing issue of hazard identification of, exposure to, and risk analysis of engineered nano-materials.

[1] A. Maynard et al., Nature, 16 November 2006

Dr. Martin Philbert works at the University of Michigan School of Public Health.

Interview by Thanh Tam Candice Vu