Forget the futuristic visions of molecular-scale devices that seek out and destroy cancer cells and repair faulty heart valves. The truth is that nanotechnology is already here. Nanoproducts
Why scientists must dispel our 'grey goo' fears By Robert Service
Published: June 17 2004 19:28 | Last Updated: June 17 2004 19:28
Forget the futuristic visions of molecular-scale devices that seek out and destroy cancer cells and repair faulty heart valves. The truth is that nanotechnology is already here.
Intel and other computer chip companies already sell tens of billions of dollars worth of chips every year packed with electronic circuitry patterned down to the nanoscale. Computer hard drives, LED-based traffic signals, CD players and low-friction coatings account for billions more in sales.
So it was only natural that you could almost hear the collective groan at a meeting of the American Chemical Society at Anaheim, California, in March, when Eva Oberdörster, a toxicologist at Southern Methodist University in Dallas, Texas, told nanoscience researchers that water laced with all-carbon nanoparticles called buckyballs could damage cell membranes in the brains of fish.
The story was picked up by newspapers around the world. Researchers and policymakers fretted that such coverage could poison public perception of all things nano, including the vast majority of applications that have nothing to do with buckyballs, and tar the science with the same brush as previous abortive revolutions such as agricultural biotechnology and nuclear power.
Nanotechnology has not yet gained that level of notoriety. But the field stands at a critical crossroads in public perception around the world. "Nanotechnology is growing up," says Vicki Colvin, a nanotechnology researcher at Rice University in Houston, Texas.
The nanoscience boom grew from the recognition that the properties of materials can change drastically as their size is whittled down from the bulk material to small clusters of atoms. Gold, for example, is inert in bulk but becomes highly re- active at the nanoscale, making it a potentially valuable catalyst. Electrical, optical, thermal and other properties of materials may undergo similar shifts.
That protean nature, coupled with new tools for studying small-scale materials, has transformed the kinds of questions scientists can ask, says John Marburger, who heads the White House Office of Science and Technology Policy: "The cap- ability to image, manipulate and visualise all materials at the atomic level potentially touches every human aspect in the world around us."
In just five years, nanotechnology has catapulted from being a specialty of a few physicists and chemists to a worldwide scientific and industrial enterprise. Worldwide, government-funded nano research has grown seven-fold, from less than $500m in 1997 to more than $3.5bn (£1.9bn) in 2004.
The March/April issue of Small Times, a US-based nanotech industry magazine, noted that venture capital funding in the nano area rose from virtually nothing in 1997 to $300m in 2003, accounting for over 5 per cent of all VC funds distributed in the US. The list of big businesses pursuing nano research includes General Electric, Lucent, Philips, Matsushita, Intel, Advanced Microdevices and Merck.
In April Merrill Lynch launched a nanotechnology index to track the stock performance of the emerging sector. According to David Rejeski, who directs the Foresight and Governance Project at the Woodrow Wilson International Center for Scholars in Washington, DC, 130 nano-based products have already been released on to the US market. And according to US government estimates, the nanotech economy will be worth $1,000bn by 2012.
This has led some to worry that the field could suffer the sort of unintended consequences that overshadowed the introduction of genetically modified foods and other industrial and technological revolutions. They are not talking about far-future "grey goo" scenarios in which speck-sized self- replicating robots devour the planet. Making such devices would be "difficult if not impossible" says Richard Smalley, a Rice University nanoscientist, and most nanoscientists agree.
A more plausible threat, they say, is that nanoparticles released from coatings or other products will create a new type of chemical pollution. "We know very little about the health and environmental impacts [of nanomaterials] and virtually nothing about their synergistic impacts", Mr Rejeski says.
Over the past couple of years, about a dozen toxicology reports have suggested that nanoparticles pose a unique risk to everything from bacteria to mammals. Exactly how various nano- materials appear to harm cells and what this may mean for higher organisms is still being researched.
"These are very early pieces of data. It is very hard to draw conclusions about the risk" when there has been so little exposure to specifically engineered nanoparticles, says Clayton Teague, who directs the National Nanotechnology Co-ordination Office in Washington. Most other observers agree it is too early to start regulating nanoparticles, but some say their concerns are growing.
Mihail Roco, who heads the US National Nanotechnology Initiative (NNI), agrees that caution is in order in dealing with new nanomaterials. In the US, the NNI, the Environmental Protection Agency, the National Science Foundation and other national programmes are funding investigations of nanomaterials' environmental effects. Some observers are not impressed, arguing that a greater percentage of nanotechnology funding should be put toward toxicology.
Still, Dr Teague says, researchers are hardly starting from scratch. "There is a large body of research on the toxicity of ultrafine [particles]", he says. This includes extensive studies of carbon soot from power plants, welding fumes, diesel exhaust, paint pigments and carbon black-based toner in photocopiers.
Currently, regulators assess the safety of new compounds based on their chemical composition. But nano- materials often change their properties when their size changes, even if their composition remains constant. Even deciding how to test nanoparticles for their toxicity is not straightforward, Ms Colvin says. Should regulators investigate 1-nanometre, 10-nanometre, or 50-nanometre particles? Should they look at all three and everything in between?
Companies that invest heavily in the field are also hurrying to ascertain the safety of nanomaterials. DuPont is funding toxicology work on nanomaterials, and other companies are backing university research at Rice and elsewhere. "[Companies] have a vested interest to make sure the train doesn't go off the track. The last thing they want is to make a massive investment and have nano turn around and bite them," Mr Rejeski says.
Behind such efforts loom the spectres of a new generation of environmental cleanup sites or, much worse, the same downward spiral in public confidence that blighted agricultural biotechnology and nuclear power.
Pat Mooney, executive director of ETC Group (formerly RAFI), which spearheaded efforts against agricultural biotechnology, agrees. Novel technologies based on nanotechnology might some day drastically lower the cost of generating electricity from solar power, purify water and clean up past environmental contamination, but researchers must be careful. "If people are too blasé about nanotechnology and it gets off on the wrong foot, then it's a problem. It is critical that scientists get it right."
Julia Moore, a senior adviser in the National Science Foundation's Office of International Science and Engineering, says companies should let consumers know up front which products contain nanomaterials.
David Goldston, staff director of the US House of Representatives Science Committee, says scientists should not dismiss public concerns as uninformed or unrealistic: "The message should be one of engagement rather than simply countering their concerns with rhetorical counter-attacks."
Finally, Dr Roco adds, the NNI must continue to back studies on environmental and other impacts of nanotechnology and disseminate them widely. "If you don't provide information, there is a perception that something is wrong", he says.
That perception may turn out to be the thing that could knock the nanotechnology train off its tracks.
This article was provided by AAAS and Science, its international journal. www.aaas.org; www.scienceonline.org