Nanotechnology offers benefits, but poses risks

Some say the emerging technology harbours hidden dangers

Warning: Your keyboard could be a danger to you and the environment.

Sound preposterous? Then consider this: Some keyboards contain nanosilver, which, because of its antimicrobial properties, is increasingly incorporated into everyday items even though some studies have questioned its health and environmental safety.

Concern over nanosilver keyboards is just the start. A growing number of organisations and scientific studies are raising questions over the proliferation of nanotechnology, which can be found in numerous consumer and commercial products, from IT components and cars to clothing and cosmetics.

Sheila Davis, executive director of the Silicon Valley Toxics Coalition (SVTC), a San Jose-based advocacy group, says "The biggest issue around nanotechnology is that we don't know [all of its risks]. We're putting things on the market that haven't been fully tested," she says.

Nanotechnology refers to work done on the nanoscale, with one nanometer equaling a billionth of a meter, or about 1/100,000 the thickness of a sheet of paper. Yet, ironically, the term nanotechnology encompasses a broad set of work. It applies to the manipulation of common materials (including carbon, silver and polymers) on the atomic and molecular levels to exploit specific properties. Carbon nanotubes, for instance, are stronger than steel yet lighter than plastic.

The term also applies to work done on the nanoscale (generally anything smaller than 100 nanometers) using conventional materials. Intel, which uses the term nanoelectronics, now has a transistor that measures 45 nanometers.

Use of this technology can not only save resources and energy; it also has the potential to revolutionize our world. Scientists say they could use nanotechnology to build an elevator to space, deliver drugs precisely within the body and capture the maximum amount of solar energy for electricity.

But there's also concern that the explosion in nanotechnology research and applications could be harmful to humans and the environment. "The nanotech boom is generating an unprecedented number of new processes and materials that pose unknown potential environmental and health hazards," the SVTC states in its April 2008 report on nanotechnology and its risks.

Scientific studies also have found potential health and environmental problems with nanomaterials.

A study published in the May issue of Nature Nanotechnology suggests that long, thin multiwalled carbon nanotubes, which researchers are using to build next-generation circuits, could be as harmful as asbestos and potentially cause a cancer of the lung lining called mesothelioma if inhaled in sufficient quantities.

A 2004 study published in the journal Toxicological Sciences found that mice intratracheally instilled with single-wall carbon nanotubes showed signs of pulmonary toxicity.

And a January 2008 article called "Nanotechnology Safety Concerns Revisited", also published in Toxicological Sciences, offered more words of caution: "The potential pulmonary toxicity of certain nanomaterials, such as carbon nanotubes, is significant, requiring a better understanding of exposure to further evaluate their risk."

Jennifer Sass, a senior scientist with a specialty in toxicology at the Natural Resources Defence Council in New York, says "This isn't a technology we want to say no to, but it's a technology we want to move safely and intelligently into the future".

She adds: "What we have to consider with new physical properties is that there's likely to be a new toxicology profile. We have to consider that and do more testing before people are exposed or it's released into the environment."

Sass' comments bring us back to that keyboard. Does yours contain nanosilver, a substance that studies suggest can damage part of the human cell that creates cellular energy and induce oxidative stress in people as well as disrupt the nitrogen balance in freshwater ecosystems?

Most likely, you don't know. And you probably can't easily find out. Many products don't disclose — nor are they required to by law — that they contain nanomaterials, according to Sass, Davis and other nanotechnology researchers.

What does that mean for a data-entry operator typing all day? Or for the IT worker setting up desktop systems, handling upgrades or changing cards, all of which may contain either nanomaterials or components containing nanoelectronics?

And what happens when those products need to be replaced? If that computer keyboard is recycled, would that nanosilver be released into the air or water?

"Those are the issues that need to be addressed, and they're just not on the table right now," Davis says.

But others counter that statement. They say that while scientists need to do more research, they already know that a number of factors limit the potential dangers posed by nanotechnology.

One of the most significant factors to consider is the fact that humans evolved in the presence of nanoparticles, says R Stanley Williams, director of information and the quantum systems laboratory at HP Labs.

"People are concerned about manmade nanoparticles in the environment, and there is certainly reason to be careful and not do anything foolish. But on the other hand, human beings aren't the only nanotechnologists on earth. There are thousands of species of animals that synthesise nanoparticles, and our environment is filled with nanoparticles. We just didn't know it until we had tools that could see them," Williams says.

Even so, industry is taking steps to minimise exposure.

Leading manufacturers, whose workers likely face the greatest risk of exposure, follow protocols to contain manufactured nanoparticles as well as any conventional materials fabricated on a nanoscale, says Mihail Roco, senior advisor for nanotechnology at the US National Science Foundation.

Workers at Intel wear protective gear, use HEPP (high-efficiency pleated polypropylene) filters and work under hoods where air pressure pulls wayward particles away from workers and into filters, says Todd Brady, Intel's corporate environmental manager.

The company, which makes nanoscale transistors for its chips and experiments with nanomaterials, has also teamed with universities and government agencies to explore applications and health and environmental implications arising from nanotechnology.

"We want to look at our technology roadmap and see what risks there might be with any of the materials we'll use so we can take steps to minimise them," Brady says.

Technology users also have a measure of protection against exposure thanks to the very nature of nanotechnology, Roco and others say.

Nanoparticles are bound with other materials to make a final product, and although data on whether they can be released during use or disposal is still being gathered, scientists point to studies that show the nanomaterials stay bound and therefore won't harm humans or the environment.

"These are so tightly locked down that there's no way the nanoparticles can get out. You can beat on them with a hammer, and they still won't get out," Williams says.

In fact, the Toxicological Sciences article "Nanotechnology Safety Concerns Revisited" supports the human ability to cope with nanoparticles, saying, "The available data support the ability of the lung, gastrointestinal tract and skin to act as a significant barrier to the systemic exposure of many nanomaterials. Furthermore, the acute systemic toxicity of many nanomaterials appear to be low."

Moreover, scientists, even those who more aggressively warn about potential risks, point out that nanotechnology promises health and environmental benefits.

Nanotechnology might be used to track tumours, clean up contaminated water and soil, and reduce the need for resources and energy. The potential benefits, they say, are nearly limitless.

As Semiconductor Industry Association spokesman John Greenagel says, "There's no question that we'll find uses for nanotechnology that we'll take for granted 10 or 20 years from now that we can't even think about now."

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