Nanotechnology's Big Question: Safety
Sunday, October 23, 2005
With little fanfare, the Environmental Protection Agency has for the first time ruled on a manufacturer's application to make a product composed of nanomaterials, the new and invisibly small particles that could transform the nation's engineering, industrial and medical sectors.
The agency's decision to approve the company's plan comes amid an ongoing debate among government officials, industry representatives, academics and environmental advocates over how best to screen the potentially toxic materials. Just last week, a group of academics, industry scientists and federal researchers, working under the auspices of the nonprofit International Life Sciences Institute, outlined a set of principles for determining the human health effects of nanomaterial exposures.
By year-end, the EPA plans to release a proposal on how companies should report nanomaterial toxicity data to the government.
"Toxicity studies are meaningless unless you know what you're working with," said Andrew Maynard, who helped write the institute's report and serves as chief science adviser to the Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars, a Washington-based think tank.
Because of their tiny size, nanomaterials have special properties that make them ideal for a range of commercial and medical uses, but researchers are still trying to determine how they might affect humans and animals. Gold, for example, may behave differently when introduced at nanoscale into the human body, where it is chemically inert in traditional applications.
The institute's report urged manufacturers and regulators to evaluate the properties of nanomaterials in laboratory tests, adding: "There is a strong likelihood that the biological activity of nanoparticles will depend on physiochemical parameters not routinely considered in toxicology studies."
The EPA decided last month to approve the "pre-manufacture" of carbon nanotubes, which are hollow tubes made of carbon atoms and potentially can be used in flat-screen televisions, clear coatings and fuel cells. The tubes, like other nanomaterials, are only a few ten-thousandths the diameter of a human hair.
Jim Willis, who directs the EPA's chemical control division in the Office of Pollution Prevention and Toxics, said he could not reveal the name of the company that received approval for the new technology or describe how that technology might be marketed. He added, however, that the EPA reserved the right to review the product again if the company ultimately decides to bring it to market.
Nanomaterials are already on the market in cosmetics, clothing and other products, but these items do not fall under the EPA's regulatory domain. EPA officials judge applications subject to the Toxic Substances Control Act (TOSCA), a law dating from the mid-1970s that applies to chemicals.
In a Wilson Center symposium last Thursday, Willis said "it is a challenge" to judge nanotechnology under existing federal rules.
"Clearly, [TOSCA] was not designed explicitly for nanoscale materials," he said, but he added that chemicals "have quite a number of parallels for nanoscale materials" and that "in the short term, we are going to learn by doing."
Scientific studies also suggest nanoparticles can cause health problems and damage aquatic life. For instance, they lodge in the lungs and respiratory tract and cause inflammation, possibly at an even greater rate than asbestos and soot do.
"Nanoparticles are like the roach motel. The nanoparticles check in but they don't check out," said John Balbus, health program director for the advocacy group Environmental Defense. "Part of this is a societal balancing act. Are these things going to provide such incredible benefits that we're willing to take some of these risks?"
Nanomaterials have possible environmental advantages as well. For instance, they can absorb pollutants in water and break down some harmful chemicals much more quickly than other methods.
"Just because something's nano doesn't mean it's necessarily dangerous," said Kevin Ausman, executive director of Rice University's Center for Biological and Environmental Nanotechnology. He added that when it comes to nanotechnology's toxic effects, "we're trying to get that data before there's a known problem, and not after there's a known problem."
Companies such as DuPont are pushing to establish nanotechnology safety standards as well, in part because they have seen how uncertainties surrounding innovations -- such as genetically modified foods -- have sparked a backlash among some consumers.
"The time is right for this kind of collaboration," said Terry Medley, DuPont's global director of corporate regulatory affairs. "There's a general interest on everyone's part to come together to decide what's appropriate for this technology."