Nanotechnology: the known unknowns

What’s the best way to proceed with technology that we know very little about, that has the potential to damage health? The answer would appear obvious: cautiously. Yet many are keen to race ahead with the technology despite the “known unknowns” and the lack of appropriate legislation.

Nanotechnology has already reached Australians in sunscreen, food packaging, sports equipment, clothes, electronics, construction and cosmetics. Given their tiny size, nanoparticles promise a range of applications. They could be used to deliver drugs to cancer cells, build strong lightweight plastics or even help smart clothing convert mechanical energy to electricity.

But such applications may come at a cost to human health. There is very little is known about how particles behave at the nano-scale and it cannot be guaranteed that the particles are safe when they enter the human body. As Nobel prize-winning Swiss physicist Heinrich Rohrer notes, in nature nanoparticles tend to clump together; engineered, they behave differently. Reactions cannot be predicted and toxicology cannot be accurately judged or measured.

Occupational physician and council member of the Australasian Faculty of Occupational and Environmental Medicine, Ian Gardner, is "concerned with a small c" about nanotechnologies, particularly in the case of nanotubes, cylindrical nanostructures. As an expert in occupational medicine, he observes the interconnections between life and work. He points to the link, for instance, between asbestos and lung disease. He suspects some nanotubes "may act very similarly".

Nanoparticles are so small they can penetrate skin, be absorbed through the lungs or be distributed widely through the bloodstream, and can even track up the olfactory nerve, a smelling nerve that extends through the back of the nose, reaching straight into the brain.

While health specialists have yet to produce evidence on the potential human health effects of exposure to nanoparticles, Gardner's career has taught him to look elsewhere when determining the first indications of new occupational hazards. "If you want to find where the risks are, you look to the insurance industry," he says. "The insurance industry in North America knew by 1916 that asbestos workers died early. They didn't know specifically that they died of mesothelioma or lung cancer, but they knew the risk and they loaded the premiums of asbestos workers."

Swiss Re, one of the world's leading re-insurers, held its first conference on nanotechnology in 2005. At the meeting former chief executive John Coomber cautioned: "None of us can afford not to care (about nanotechnology)." In a 2008 report titled Nanotechnology: Small Matter, Many Unknowns, Swiss Re noted: "The supposition that the potential for harm could be similar (to asbestos) would appear to be obvious."

Swiss Re's pre-emptive strike raises cause for concern, claims Georgia Miller, nanotechnology spokeswoman for Friends of the Earth Australia. She sees a perversity to the technology. While acknowledging nanotechnology has enormous potential, her group is calling for a moratorium on its use until health concerns can be addressed: "We're very worried that it's the same properties that make nanoparticles interesting for medics - their unique ability to access cells and other parts of the body - which make them dangerous in every other application."

The 2008 Friends of the Earth report Out of the Laboratory and on to Our Plates says more than 100 food, food packaging and agricultural products containing nano ingredients are on sale internationally, including diet replacement milkshakes and additives in processed meat and dairy products.

We don’t know how many nano foods are now on sale in Australia because companies are not required to label nano ingredients. According to Miller, four or five years ago big food brands such as Kraft, Nestle and Unilever talked openly about their interest in nano. Now they avoid interviews and provide little information about the use of nano components in their products.

Without such information the public has no choice about exposure to nanotechnology. Products containing nanoparticles do not have to be labelled in Australia and companies using nanotechnology are not required to inform their employees of the fact.

A 2008 New South Wales inquiry into nanotechnology, conducted by the NSW State Development Committee chaired by Tony Catanzariti, acknowledged that regulation of nanotechnology was inadequate. Yet the federal government has yet to give a formal response to the findings in the report. It remains unclear whether or not Innovation, Industry, Science and Research Minister Kim Carr will support the approach recommended in the report and make nanoparticles go through new safety testing before being put on the market.

Gaps in our knowledge of the technology include questions such as: can nanoparticles used in food packaging be absorbed by the food inside? In the recycling of nanomaterials, do chemical particles end up in effluent, and to what effect? What is the life cycle of the particles in the human body?

The gaps are real, but Gardner says it's not yet time to panic. "To put it in perspective, as of today, the levels of risk are very low, but the reason is because (nanotechnology is) only really being used in significant amounts in very highly sophisticated, well-controlled research laboratories," he says.

"The next step, when it becomes business as usual, that's my biggest concern,” says Gardner, who recommends that, until all that work has been done, we tread carefully.

While there are gaps in our understanding of nanotechnology and its effects, the best way to avoid a repeat of the effects we witnessed - and are witnessing still - from the use of asbestos is to proceed cautiously. Doing so requires a regulatory framework within which employers, employees and consumers can operate, as well as the full involvement of these communities so that they are informed and armed with the right tools to make choices and avoid risk.