The Smaller the Better

The limitless promise of nanotechnology -- and the growing peril of a moratorium.

Ronald Bailey from the December 2003 issue

(Page 3 of 5)

The effects of loose nanoparticles do need to be (and are being) studied. But contrary to the ETC Group's implication, heedless scientists and greedy corporations are not about to flood our bodies and the world with dangerously toxic nanoparticles. It's important to recognize that people already breathe in lots of nanoparticles. Humanity began manufacturing them as soon as we tamed fire. And as Ken Lyon, director of business development at Altair Nanomaterials, notes, "Nature made nanomaterials a long time before mankind started making them on purpose. There are lots of natural sources of nanomaterials -- salt particles from ocean storms, for example. They are all around us. Enzymes and viruses are all in the nanosphere."

Gunter Oberdorster, a professor of environmental medicine at Cornell University, has noted that "ultrafine particles [smaller than 20 nanometers] have the highest number concentration but the lowest mass concentration, a major anthropogenic ETC source being emissions of internal combustion engines," especially diesel engines. Matter Engineering, a Swiss firm specializing in the measurement of ambient nanoparticles, notes that each cubic centimeter of urban air already contains about 10,000 nanoparticles. Natural sources of nanoparticles include volcanic activity, forest fires, and sea spray. Of course, breathing particulates is not good for your lungs; studies show that air pollution increases the risk of lung and cardiovascular diseases. But there's little reason to believe that manufactured nanoparticles raise special concerns in this connection.

Keep in mind that most manufactured nanoparticles are not going to be running around loose. Altair's Ken Lyon notes, "Nanomaterials are usually incorporated into something else -- ceramic coatings, glass, plastics. By the time it's in a coating, it no longer exists as a nanomaterial." Altair makes titanium dioxide nanoparticles that are incorporated into products such as self-cleaning glass and UV-blocking sunscreens. Titanium dioxide is considered to be so nontoxic that it is approved for use in food, generally up to 1 percent of the product's final weight. A 1998 Environmental Protection Agency risk assessment concluded, "Based on its low toxicity, there is reasonable certainty that no harm will result from aggregate exposure to the U.S. population, including infants and children, to residues of titanium dioxide." Lyon notes, "We know what happens to people who ingest titanium dioxide: Their poop turns white."

Pat Collins of Hyperion Catalysis International, which makes multiwall carbon nanotubes for use in products such as automobile plastic composites, points out: "We compound our carbon nanotubes into plastics. You can sand, grind, slice, and dice, and the nanotubes won't get liberated. We've looked for free nanotubes and have never found them. The plastic particles in which the nanotubes are incorporated are much bigger than the nanotubes themselves."

Asked about the ETC Group's proposed moratorium, Collins says: "I don't want to get into a public pissing match, but I don't think it's a valid concern. What they're talking about is all very hypothetical risks. There's no risk using nanotubes in plastics." Lyon also rejects the call for a moratorium but agrees that "the industry has an obligation to be cautious as we develop new products." He says "adequate steps are being taken to make sure that people exposed to the stuff are safe."

We don't have to just take the nanotech industry's word for it. The National Science Foundation established a Center for Biological and Environmental Nanotechnology (CBEN) at Rice University; its mission is to evaluate the health and environmental effects of new nanomaterials. Kevin Ausman, CBEN's executive director, says the ETC Group's concerns are "based largely on speculation and hypotheses." About the proposed moratorium, Ausman says: "I don't think a ban is reasonable. It's such a broad class of materials; if we have to wait until everything is proved absolutely safe, we're never going to develop nanomaterials. What you need is a parallel development of the application of nanomaterials and impact assessment at the same time." In other words, proceed with caution.

Paul Burrows, manager of the Nanoscience Initiative at the federal government's Pacific Northwest National Laboratory, says of nanomaterials: "I wouldn't eat them. We should treat nanoparticles like we would any other chemical." Burrows notes that our current technologies contain a lot of materials that would be hazardous if they didn't stay put. "Your cell phones contain chips with gallium arsenide in them," he says. "Arsenic isn't good for you."

Ausman notes that most particulate inhalation problems, such as black lung or silicosis, "result from exposures over a long time and at high levels; occasional exposures for short periods would not be dangerous." He expects the same would be true for nanomaterials such as carbon nanotubes. Ausman also thinks the laboratory "best practices" regime envisioned by the ETC Group is unnecessary. "The standard precautions in labs and manufacturing are sufficient to protect people in labs and factories," he says. "They are part of a research community used to handling hazardous materials."

The ETC Group is fond of quoting CBEN Director Vicki Colvin's estimate that only $500,000 has been spent so far on evaluating the health and environmental risks of nanotechnology. An irritated Mihail Roco dismisses Colvin's claim as the grandstanding of "a younger researcher who is trying to raise money for her center." Colvin's center is spending $500,000 on environmental research, Roco says, but the National Nanotechnology Initiative is spending about $50 million researching the environmental and social issues raised by nanotechnology. In any case, he says, "It would be unwise to spend 50 percent of nanotech research money thinking about the societal and environmental issues of products that will not ultimately be developed." Or as Ausman puts it, "I am not worried that in the near term nanomaterials are going to cause any serious problems," and "there's a lot of lead time before there's a lot of stuff out there."

Gray Goo

The second nanotechnology risk that worries ETC Group activists is runaway self-replication. Mooney points to a scenario suggested by Eric Drexler himself in The Engines of Creation: Self-replicating nanobots get out of control and spread exponentially across the landscape, destroying everything in their path by converting it into copies of themselves. In this scenario, the biosphere is transformed by rampaging nanobots into "gray goo."

But according to Nobelist Richard Smalley, "Self-replicating nanorobots like those envisioned by Eric Drexler are simply impossible to make." Mihail Roco likewise dismisses such nanobots as "sci fi," insisting there is "common agreement among scientists that they cannot exist."

Drexler replies, reasonably enough, that we know nanoassembly is possible because that's what living things do. Cells, using little machines such as ribosomes, mitochondria, and enzymes, precisely position molecules, store and access assembly instructions, and produce energy. Some have quipped that biology is nanotechnology that works.

As that analogy suggests, there is a close affinity between nanotechnology and biotechnology. "The separation between nanotechnology and biotechnology is almost nonexistent," said Minoo Dastoor, a senior adviser in the National Aeronautics and Space Administration's Office of Aerospace Technology, at the National Nanotechnology Initiative's conference in April. For future missions, NASA needs machines that are resilient, evolvable, self-sufficient, ultra-efficient, and autonomous. "Biology seems to be able to do all these things very elegantly and efficiently," noted Dastoor. "The wet world of biology and the dry world of nanotechnology will have to live side by side and merge."

The fact is that no one has yet definitively shown that Drexler's vision of molecular manufacturing using nanoassemblers is impossible. So let's suppose Smalley and Roco are wrong, and such nanobots are possible. How dangerous would self-replicating nanobots be? One of the ironies of the debate over regulation of nanotechnology is that it was nanotech boosters like Drexler who first worried about such risks. To address potential dangers such as the uncontrolled self-replication envisioned in his gray goo scenario, Drexler and others founded the Foresight Institute in 1989. Over the years, Foresight devised a set of guidelines aimed at preventing mishaps like a gray goo breakout.