The EPA Gets Its Act Together

The Environmental Protection Agency (EPA) has released a Nanotechnology White Paper for external review. They should be commended as they have come a long way in a short time period. The following paragraphs, about a meeting held a couple of years ago, were adapted from my book, The Nanotech Pioneers: Where are they taking us?

I was fortunate enough to be present at an informational meeting held in Washington between nanotech industry trade group leaders and representatives of the U.S. Environmental Protection Agency (EPA) and the Food and Drug Administration held in 2003. The meeting was held as an exchange of ideas about what challenges the nascent nanotechnology industry might present to regulators. The presentation of the EPA was illustrative of the problems that the EPA faces with nanomaterials. For instance, certain chemicals it considers hazardous require special care in handling, transportation, storage and disposal. The EPA categorizes chemicals, naturally, on the basis of their chemical formula. But consider the problem of carbon nanotubes. To the EPA in 2003, a carbon nanotube was just carbon, the same as graphite, the same as diamonds, the same as carbon black (colloidal carbon). There was no special care required in handling carbon nanotubes at that time, and for that matter, as virtually no toxicology had been performed, nobody knew whether nanotubes were dangerous or not.

The EPA representative did his best to reassure the nanotech leaders that his agency was not about to do anything to stifle the growing nanotech industry. On the other hand, trade group leaders, particularly Bo Varga of NanoSIG, argued vociferously that the EPA should indeed step in with serious regulation.

The expected roles were reversed—the regulators not wanting to regulate while the potential regulatees were demanding it. How to explain this weird discrepancy? Beyond the talk of “grey goo” and the public’s reaction to the inevitable movie version of Michael Crichton’s novel Prey, there were real concerns:

1) The uproar over genetically-modified organisms (GMO) or “Frankenfoods” has convinced high tech industry in general that public relations are important. One of the spinners of the Frankenfoods controversy, the radical environmentalist organization RAFI (Rural Advancement Foundation International) has been reborn as Etc Group and has nanotech in its sights. They have released a couple of very negative reports on what they call Atomtech.

2) People in the industry recognize that some nanoparticles, eg carbon nanotubes, could have real health risks similar to asbestos in an unregulated environment. The first “Love Canal” type environmental episode might have a seriously detrimental effect on the nanotech industry as a whole.

Nanomaterials can easily generate adverse consequences if they enter the human body. Looking from a biological perspective, on first principles, one can see, for instance, that carbon nanotubes would be very hydrophobic and therefore difficult to eliminate from the body. The extremely small diameter suggests that they could easily penetrate cells (which in fact, they do). Carbon nanotubes are also physically just about indestructible and unlikely to be easily biodegraded. Carbon nanotubes also have a tendency to aggregate and therefore there is a high probability that they would tend to collect in the lungs and perhaps in the nephrons of the kidney. But until recently, nobody had done any real toxicology on carbon nanotubes.

The EPA’s white paper suggests that they are now taking the problem seriously:

A search of the literature on particle toxicity studies published up to 2005 confirms the paucity of data describing the toxicity of chemically defined ultrafine particles and to an even greater extent that of intentionally produced nanomaterials, The ability to assess the toxicity of intentionally produced nanomaterials by extrapolating from the current particle toxicological database was examined by Lam et al. (2004) and Warheit et al. (2004). Their findings demonstrate that graphite is not an appropriate safety reference standard for carbon nanotubes [No kidding!], since carbon nanotubes displayed very different mass-based dose-response relationships and lung histopathology when directly compared with graphite.

Studies conducted by Lam et al. (2004) and Warheit et al. (2004) examining the pulmonary toxicity of carbon nanotubes, have provided evidence that intentionally produced nanomaterials can display unique toxicity that cannot be explained by differences in particle size alone. For example, Lam reported single walled carbon nanotubes displayed greater pulmonary toxicity than carbon black nanoparticles. Similar results have been obtained from comparative in vitro cytotoxicity studies (Jia et al.,2005). Muller et al. (2005) reported multi-walled carbon nanotubes to be more proinflammatory and profibrogenic when compared to ultrafine carbon black particles on an equivalent mass dose metric. Shvedova et al. (2005) reported unusual inflammatory and fibrogenic pulmonary responses to specific nanomaterials, suggesting that they may injure the lung by new mechanisms.

Which is not to say that carbon nanotubes or other nanomaterials should not be developed. But if I worked in a factory where they were produced, I would want to be assured that procedures were in place to make sure that nanomaterials didn’t become aerosolized. Reasonable precautions should not, and so far, have not been resisted by the industry.