Will grey goo take over the world?

Paul Burall explains why we may need to start worrying about nanotechnology, although probably not for the reasons the popular press have been promoting

Some of our national newspapers had a field day earlier this year with a scare story about the likelihood of the world being taken over by grey goo created by a plague of nano-robots that will take over the world. The story was prompted by Prince Charles asking questions about nanotechnology, a subject that so few people know anything about that the prime source of information appears to have come from the 1986 book Engines of Creation written by Eric Drexler, founder of the US Foresight Institute. It was Drexler who developed the idea of man-made nano-robots that would run out of control, replicating themselves by eating everything and leaving behind a world of grey goo.

Science fiction? Not according to the Astronomer Royal, Sir Martin Rees. In his new book Our Final Century: Will the Human Race Survive the Twenty-First Century? (published by Heinemann), Rees says that the grey goo idea of self-replicating machines eating the entire biosphere does not breach any known physical laws. But he then qualifies this by saying that this is as far beyond our current technology as a starship capable of flitting from planet to planet at 90% of the speed of light, which puts the threat almost into the realms of science fiction.

But what is nanotechnology? And do we need to worry?

The first point to make is that everyone who has looked at the technology is convinced that it is the future. This is no nutty off-the-wall fantasy that will disappear as fast as you can say 'cold fusion'.

Second, there are genuine reasons for caution. Drexler's nightmare vision may be nearer to science fiction than science fact but there are real worries about the consequences for health, for the environment, and for world power.

So what is nanotechnology?

Nanotechnology allows the construction of products molecule-by-molecule, in some cases atom-by-atom. It allows the construction of tiny machines that can carry out tasks that are impossible by traditional means. And, because every particle used has a purpose, it does away with waste.

Manufacturers are already using the term to describe ever-smaller devices, especially in the electronics industry, although these are not yet truly based on molecular construction.

For example, Hewlett Packard has recently come up with a way to make nanoscale wires separated by just a thousand molecules, opening new possibilities for microelectronic miniaturisation and memory storage.

At a lot of money is beginning to be invested in research and development and nanotechnology seems certain to be one of the key technologies for the future.

Christine Peterson, President of the Foresight Institute, told the US House of Representatives Committee on Science in April that "Nanotechnology will take us beyond materials and devices to complex systems of molecular machines inspired by, but in some ways superior to, those found in nature... It is important not to minimise the technical challenge of such a complex systems engineering project. Nonetheless, ongoing research is building the needed technology base and will eventually place enormous payoffs within reach."

Ms Peterson suggested four key areas for the application of nanotechnology:

• Medical: Molecular machine systems could sense and rearrange patterns of molecules in the human body, providing the tools needed to bring about a state of health, regardless of the cause of a disease.
• Environmental: Using molecular manufacturing techniques it will be possible to construct products with zero chemical pollution, recycling leftover molecules. Environmental restoration could be carried out at the molecular level, detecting and inactivating unwanted chemicals.
• Raising sustainable living standards: Molecular manufacturing could cleanly and inexpensively produce high-quality products using common materials (especially carbon, which is in excess in the atmosphere in the form of carbon dioxide) and solar energy.
• Space: The strong, lightweight materials enabled by molecular manufacturing will greatly lower the cost of access to space and space resources.

Ms Peterson accepts that there are risks: "Powerful technologies bring problems as well as benefits, and advanced nanotechnologies are expected to bring problems of several sorts." She listed five:

• Accidents: Any powerful technology must be controlled to avoid accidents. In the case of molecular manufacturing, rearranging matter at the molecular level can either improve or destroy a system. Molecular machine systems able to build complex objects could build copies of themselves, possibly overdoing this activity from a human point of view, as bacteria do.
• Economic disruption: Technological change continually disrupts employment patterns; molecular manufacturing is expected to accelerate this significantly.
• Lack of access: Excessive or incorrect patenting of fundamental machine parts at the nanoscale may reduce commercial competition and make molecular manufacturing products too expensive for many to benefit.
• Deliberate abuse/terrorism: Of the potential problems molecular manufacturing may bring, this is regarded as the most serious and most challenging to address. Three main areas of concern have been identified: (1) very rapid construction of conventional weapons, making traditional arms control more difficult, (2) totalitarian control of civilian populations by surveillance using nanoscale sensors, and (3) new weapons made possible by the technology, which can be thought of as 'smart' chemical weapons.

There are more specific concerns. Vicki Colvin, Director of the Center for Biological and Environmental Nanotechnology in Texas, points out that fine particles can directly damage health. "Quartz, for example, is perfectly safe in bulk, but miners, rock cutters and sandblasters who are exposed to quartz dust are at risk of silicosis".

Again, although hip and knee replacements are made from materials that are well tolerated by the body, they can shed fine particles into the surrounding tissues as they wear down, causing inflammation and, in the worst cases, loosening the implant.

Elsewhere, studies into the toxicity of nanotubes has produced some worrying results. Robert Hunter, a toxicologist at the University of Texas-Houston Health Science Center, says that the message is clear. "People should really take precautions. Nanotubes can be highly toxic," he says. "There's variability between different nanotubes and very little is known about it."

The US Environmental Protection Agency has concerns too. Carbon nanotubes have a very high surface area which other molecules stick to easily, so they could provide a route for pollution to spread further and faster than would otherwise happen. "There is an urgent need to evaluate the effectiveness of current water and air treatment techniques for the removal of potential nanoscale pollution," says the EPA.

However, of the $679 million being spent by the US National Nanotechnology Initiative this year, only $500,000 is going to study the environmental impact of the technology.

But perhaps the biggest worry is about fairness and control. The United States is clearly determined not just to lead in nanotechnology but, as far as possible, to control it. With the US National Science Foundation forecasting that the nanotech market will be worth £1 trillion by 2015, there is a real danger of yet another 'them and us' divide splitting the world into haves and have nots.

Nanotechnology may sound like a subject best left to anoraks. It is not. It needs politicians to take an interest now to ensure that the technology is developed in a controlled way for the benefit of the whole mankind.

But let us hope that the debate is based on facts rather than preconceptions. Green MEP Caroline Lucas made a fool of herself - and, more importantly, undermined her message - when she told The Guardian earlier this year that "The laws of physics do not apply at the molecular scale". We need a debate. But it must be an informed debate.

• Paul Burall chairs the LibDem Environmental Assessment Group and is the author of Product Development & the Environment, published by Gower. He is also edits Challenge.