Nanotechnology: Really, really small stuff that's really big

You may never have heard of it, but chances are some of the products you use make use of nanotechnology. These products include particles so small, they might be able to pass through the wall of a cell.

Nanomaterials are measured in nanometres or millionths of a millimetre. A human hair is 100,000 times thicker than a particle measuring one nanometre.

Proponents hail nanotechnologies as the next industrial revolution, with the potential to make cancer therapy more effective, consumer products more durable, solar cells more efficient and revolutionize the natural gas industry. Those developments could be years away.

Nanoscale chemical substances, or nanomaterials, behave differently from their full-sized counterparts. Nano-gold, for instance, shows dramatic changes in properties and colour with only slight changes in size. Titanium dioxide nanoparticles in sunscreen are transparent to visible light, but absorb UV light. The same chemical in its conventional form is thick, white and opaque, and is used in products such as house paint and adhesives.

Titanium dioxide accounts for 70 per cent of the worldwide production of pigments. It has also been classified by the International Agency for Research on Cancer (IARC) as a possible human carcinogen.

The question many are asking is whether or not the novel properties of nanomaterials give rise to new exposures and effects, and would that mean that already-approved chemicals should be reassessed for their potential impact as nanomaterials on human health and the environment?

Explosion of new products

The number of products listed ina database of consumer products maintained by the U.S. Project on

Emerging Nanotechnologies almost tripled between March 2006 and February 2008. The project was established in 2005 as a partnership between the Woodrow Wilson International Center for Scholars and the Pew Charitable Trusts. It was set up to track developments in the industry, keep the public informed and to minimize risks to people and maximize potential benefits as nanotechnologies advance.

There are currently more than 600 products on the market that their manufacturers say were produced using nanotechnology. While nanomaterials may be used in high-tech equipment, the largest segment falls under the broad category of health and fitness products. They include 29 different sunscreens, cosmetics, clothing, tennis rackets, shoe deodorizers and optical wear.

Sales of products incorporating nanotechnology generated more than $30 billion US in 2005, according to Lux Research, a firm that charts trends in emerging technologies. The U.S. National Science Foundation estimates within a decade, nanotech products will account for a $1 trillion US slice of the global economy and the industry will employ two million people.

It's a rapidly-growing sector and yet it is a largely unregulated field.

Calls for closer scrutiny

On Nov. 12, 2008, a report out of Britain concluded there's an urgent need for more testing and regulation of nanomaterials. The Royal Commission on Environmental Pollution said there's "a plausible case for concern about some (but not all) classes of nanomaterials."

The report especially cited tiny soccer-ball shaped carbon molecules called buckyballs that may have potential uses ranging from novel drug-delivery systems to fuel cells, as well as carbon nanotubes and nanosilver.

The report warned that existing regulations might not be able to keep up with rapidly developing technology.

The commission is made up of experts from the scientific, legal, business and medical communities. The British government is required to respond to the report.

More than a year earlier, American regulators took a different view. In July 2007, a committee advised the U.S. Food and Drug Administration that food, drugs, medical devices and cosmetics that contain nanomaterials don't necessarily need special labelling to alert consumers. The agency said products incorporating the technology are not likely inherently riskier in a way that would require across-the-board labelling.

A few months earlier, the United Nations Environment Program called for tighter regulation to ensure the safety of the emerging technology. The UNEP said global test protocols and greater co-operation between private- and public-sector industries and between the developing and industrialized world was needed.

In Canada, a recent report concluded that we don't know enough about the health and environmental effects of nanomaterials and nanoproducts and that the government needs to do more to regulate them.

The report was sponsored by Health Canada and was released by the Council of Canadian Academies, a not-for-profit organization set up to provide independent, expert assessment of the science underlying matters of public interest.

The council called for:

• Development of standardized definitions and nomenclatures for nanomaterials to help regulators oversee these materials.
• Consistent monitoring of the exposure of employees and the public to nanomaterials.
• Alteration of current regulations to reflect the new chemical structures of materials.
• Canada to work collaboratively with other countries to study and regulate nanomaterials. In Canada, nanomaterials fall under the Canadian Environmental Protection Act (1999).

Currently, if a chemical has been approved under the act, it does not have to be approved again if it's later used in nanotechnology.

That may change.

Developing standards

There is no definitive international system of nomenclature for nanomaterials. However, Canada is working with other countries under the auspices of the International Organization for Standardization (ISO) to develop a nomenclature system specific to nanomaterials.

The federal government says such a system would make it easier to determine whether a particular nanomaterial is new or existing under the act.

Meanwhile, on July 20, 2008, the online journal Nature Nanotechnology carried an editorial that said an emerging technology can only be successful if those promoting it can show that it is safe. It went on to caution that "history is littered with examples of promising technologies that never fulfilled their true potential and/or caused untold damage because early warnings about safety problems were ignored." The editorial cited a 2001 report by a panel commissioned by the European Environment Agency, which looked at 14 incidents in which not heeding early warnings about emerging technologies led to a failure to protect human health and the environment.

The panel came up with 12 lessons on how to avoid past mistakes when new technologies are introduced. A couple of them may be key to public acceptance of nanotechnology:

• Systematically scrutinize claimed benefits and risks: If proclaimed benefits don't materialize in the near term despite heavy public investments or concerns are not investigated and later turn out to be significant, public trust will suffer.
• Retaining regulatory independence: The public will remain skeptical if the promoters of a technology whether government or industry have a strong influence on its oversight.

Carbon nanotubes have been cited as the poster material for nanotechnology. They are incredibly strong yet flexible and can conduct electricity better than any material ever discovered. They have the potential to make thin yet cheap televisions, stronger plastic parts for cars and effective delivery systems for drugs.

Those are the pluses.

Carbon nanotubes also attracting attention because of potential negative effects. A study out of the University of Waterloo published in May 2008 suggests that carbon nanotubes may be toxic to certain micro-organisms that digest bacteria in water. The researchers say this could eventually lead to an explosion of certain bacteria populations, which could be devastating for the environment.

Another study suggests that carbon nanotubes could trigger diseases similar to those caused by asbestos. The researchers found lesions similar to those caused by asbestos when carbon nanotubes where introduced to the abdominal cavities of mice.

The International Agency for Research on Cancer has nominated carbon nanotubes for review.