NANO LITTERBUGS? EXPERTS SEE
POTENTIAL POLLUTION PROBLEMS
Small Times Correspondent
WASHINGTON, March 15, 2002 – Scientists and government officials this week debated how nanotechnology might help – or harm – the environment, just as the U.S. Environmental Protection Agency (EPA) prepares to launch its first investigation of the potential "dark sides" of the industry.
Nanotechnology has the power to make the environment cleaner, they all agreed, but the manufacture and use of nanomaterials also offers up plenty of environmental unknowns. It’s important that scientists now begin to explore possible negatives because "prevention is a lot better than cleanup," said Vicki Colvin, a professor and co-director of the Center for Biological and Environmental Nanotechnology at Rice University in Texas.
About 15 people, most of them interested EPA officials, attended the Monday meeting, titled "Nanotechnology: Environmental Friend or Foe," at the EPA’s downtown Washington, D.C. offices.
For now, the EPA doesn’t actively investigate how nanomaterials might negatively interact with the environment, but that may change. This year for the first time, the federal agency is paying for research that will scrutinize nanotechnology from an environmental perspective. The bidding process for the grant money is just starting now. It’s unclear how much the agency will spend on the "dark side" research, although it will come from a pool of $5 million the agency plans to spend next year on nanotechnology research in general.
Colvin and Mark Wiesner, also a Rice University professor who is affiliated with the Center for Biological and Environmental Nanotechnology, laid out for the audience a smattering of environmental issues they are exploring in their research. The center, which focuses on intersections between nanotechnology and the environment, is the only one of its kind in the nation.
"What happens when (some nanomaterials) get into the environment?" asked Wiesner. "There is a health issue here. Are these things degradable? Are we creating nanoplastic bags and nanoplastic chips that are littering the nanoenvironment? How persistent are these things?"
Understanding how nanomaterials and the environment interact is a "huge, complex, interdisciplinary problem" that requires collaboration between chemists, environmental engineers, chemical engineers and biologists, Colvin said. Little work has been done to examine nanomaterials in the environment, even as the science has propelled technologies out of labs and into factories.
Nanotubes and fullerenes, for example, are entirely new types of matter that are now being produced, yet little is known about how they interact with the environment.
"One thing we’ve concluded is whatever these things are going to do, they’re not inert," Colvin said. "What will they do when they get into the environment, and what will they do when they get into people? One thing they’re definitely going to do is absorb material. If you have nanomaterials in a stream, they will be transported in some fashion."
In addition, she said, nanomaterials can insinuate themselves into cells, which Colvin said is unusual for most inorganic materials. What will they do at the cellular level? It’s unknown, she said, although it's certain that nanomaterials will interact with biology in ways that larger materials cannot.
In environmental science, the way contaminants concentrate in parts of the food chain is called bioaccumulation. For bioaccumulation to occur, substances must be long-lived, mobile, soluble in fats and biologically active. Many nanomaterials have the first three properties. The degree to which they affect the biological process is unknown, but being researched, she said.
One "huge issue" is the question of what could be done if it was determined that a nanomaterial was harmful to the environment and needed to be removed.
"How could you remove it or sense it?" she asked. For now, she said, no research is being done on that question.
Wiesner echoed Colvin, asking, "If we were to decide we wanted to regulate it, how would we know" how to find nanomaterials? "We don’t have a nanomeasure."
Wiesner said the center is helping to develop scientists who "have an environmental perspective on this technology."
"We have a real opportunity because this is a new area," he said. "We’re at a powerful point in the evolution of this technology."
The center focuses on the environmental impacts of nanomaterials through materials acquisition, the manufacturing process, distribution, use and disposal.
Tests revealing accumulations of materials in the livers of laboratory animals demonstrate that nanoparticles will accumulate within organisms, he said.
"We know nanomaterials have been taken up by cells. That sets off alarms," he said. "If bacteria can take them up, then we have an entry point for nanomaterials into the food chain."
He said that researchers need to examine whether nanoparticles absorbed into bacteria in any way enhance the ability of other materials, including toxic ones, to "piggyback" their way into the bacteria and cause damage.
He also said that "we know if we are making this material, there are bad reagents that if not handled properly are going to pose environmental problems."
Tina Masciangioli, an AAAS Environmental Science and Technology Policy Fellow with EPA’s National Center for Environmental Research, championed the work of Colvin and Wiesner, saying that it is vital to look into nanotechnology's potential impact on the environment.
But she also hailed nanotechnology as a potential ally in the war against pollution. She said nanotechnology can play a role in areas of concern to environmentalists: pollution prevention, treatment and remediation.
Benign nanomaterials, she said, may help make more manufacturing processes "green" by being used to replace toxic substances. She also envisions the use of nanotechnology to produce "bar codes" that would be affixed to, for example, toxic substances, alerting authorities to the presence of dangerous materials in the environment.
Environmental science is full of attempts to introduce pollution-busting properties into the pipes toxic substances travel through, and here nanotechnology has potential, she said. Iron is now being used in pipes to reduce contaminants. Scientists, however, have found that nanosized iron greatly improves the efficiency of the reaction between iron and contaminants.
She also said nanotechnology should help clean up the computer chip-building manufacture process, adding that the ways in which nanotechnology has the potential to improve the environment are limited only by the imagination.
"There were great breakthroughs this year" in nanotechnology, she said. "This will open up so many avenues for environmental protection. As we're doing this research, however, we have to think about the possible implications."