Managing the risks of nanotoxicity

by Phil LoPiccolo, Editor-in-Chief

Companies need to be more diligent about determining the environmental, health, and safety (EHS) risks of nanomaterials, and about sharing their findings with fellow nanotech companies, regulatory agencies, and consumer groups, according to Lux Research senior analyst Michael Holman, speaking at the Lux Executive Summit on Commercializing Nanotechnology held last month in Cambridge, MA. Taking a more proactive approach, he asserted, will not only help determine the actual risks, it will also help contain nanotech EHS research costs, ensure appropriate industry regulation — and alleviate unfounded fears based on perceived vs. real risks, thereby minimizing the potential for consumer backlash against nanotechnology-based products.

Concern about nanotech EHS, Holman said, has become the topic raised more than any other among his clients. Much of their anxiety stems from the fact that most people find the issues abstract, because of a lack of conclusive data about the complex interactions of nanoparticles with living organisms and the environment.

To illustrate the difficulties of analyzing the environmental impact of nanomaterials, Holman cited the recent nanotoxicity controversy involving fullerenes, the microscopic-sized carbon-60 molecules discovered in 1985 by a group at Rice U. and resembling the geodesic-dome geometry popularized by noted architect Buckminster Fuller. Finding the materials to be effective antioxidants, researchers proposed adding them to anti-aging facial creams, sunscreens, a host of other cosmetic and medical products.

Recent research, however, has focused on the EHS risks fullerenes might pose after being released into the environment — specifically, the nanoparticles’ effect on aquatic organisms. In 2004, Southern Methodist U. environmental toxicologist Eva Oberdorster exposed several largemouth bass to a solution of uncoated fullerenes at concentrations comparable to those of related compounds currently found in water environments. Two days later, she dissected the fish brains and found significantly elevated levels of lipid peroxidation, free radical oxidation damage that can impair the normal functioning of cell membranes and that has been linked to Alzheimer’s disease in humans. Citing the increasing use of fullerenes and other nanomaterials, she called for additional research to help prevent the possibility of damage to human health and the environment.

The story was reported extensively in the media, and almost overnight the experiment changed the image of fullerenes from wonder drug to deadly toxin, said Holman. Citing Oberdorster’s findings, the International Center for Technology Assessment and the Friends of the Earth environmental group recently petitioned the FDA to ban the use of nanomaterials in cosmetics.

However, since Oberdorster research was published, some scientists (including a group of Ukrainian chemists) have questioned whether the toxicity in the fish was actually caused by the solvent used in preparing the experiment’s fullerene solution, and not by the C60 fullerene molecules. Other studies have shown negligible toxicity — and even protective effects — of fullerenes prepared without organic solvents.

“The point of the story is not to denigrate the toxicology work that has been done on nanomaterials or to say that there aren’t serious EHS challenges associated with them,” said Holman. Rather, it highlights the need for a diligent effort to acquire more conclusive data about the true risks of these novel materials. Indeed, determining real risks would not only help ensure the safety of nanoparticles, he said, it would also alleviate EHS concerns from consumer groups and regulatory agencies, and avoid backlash based on perceived risks.

Dealing with uncertainty

In the meantime, there remains a great deal of uncertainty about the EHS risks of nanomaterials, and investors and executives still need to make business decisions about nanotechnology. “You can’t simply throw up your hands and walk away from the field until all the uncertainty is resolved,” while competitors move ahead with innovation and products, Holman said. On the other hand, no responsible company would just press on without worrying about EHS. “Companies that wait until just before product launch to even consider EHS issues will get burned badly and often,” he noted.

In the face of such uncertainty, companies can still move forward, balancing safety needs with commercial reality, Holman said. One effective strategy is employing the concept of “stage gates” — breaking down product development into several steps, and proceeding from one step to the next only when EHS concerns related to that level are resolved. For example, to apply this approach during the early stages of research on new materials, one obvious step companies can take is to review the literature for toxicity information on similar materials. They also can conduct simple in vitro tests, such as assays on skin or lung tissue, using a large number of derivatives to screen for toxicity, he said (see figure).

Focusing on the more benign materials with dramatically lower toxicity profiles can reduce the risk that research dollars will go to waste further down the road. Companies should also consider using computer models to predict other likely biological and environmental interactions of nanomaterials. Moreover, it’s key to share the results with the nanotech community through regulatory agencies or other vehicles to help contain costs industry wide.

As products move from research into development, attention can turn to assessing the likely exposure potential across the lifecycle, since risk is a function of both hazard and exposure, Holman explained. Based on what’s known about hazard, appropriate manufacturing controls and worker safety features can be put into place, and tests can be done on the product to determine to what extent nanotech particles could leach out during use or after disposal. Finally, as the product is scaled up to launch, final toxicity tests and exposure controls can be put in place to confirm material safety, and monitoring of products in the field can be used to ensure that no downstream issues arise.

“It’s so important for us, not just as a business community, but also as a society, to deal with nanotech EHS issues effectively,” Holman said. “Nanotechnology promises societal benefits on a huge scale, from developing clean energy through nano-enabled solar cells to curing diseases with nano-based drugs. It would be shame if we weren’t able to realize this potential, just because we didn’t manage the risks properly.” — P.L.

Part 2 of this report will describe strategies presented at the Lux Executive Summit for companies to communicate accurate information, not only on potential nanotoxicity risks, but also on the environmental benefits that nanonmaterial-enabled products can provide.

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