May 5, 2010

Scientist Shows How To Beat Toxic Nanoparticles

An Australian scientist will be honored tomorrow for her work in helping to ensure that humans will not have to live with the dangers of toxic nanoparticles.

Dr Amanda Barnard, will receive the Australian Academy of Science's 2010 Frederick White Prize for her world-leading research into how nanoparticles will react in different environments, which is aimed at guarding the Earth against pollution from a new category of potentially hazardous materials.

Using Australia's most powerful supercomputer, the National Computation Infrastructure (NCI), Amanda investigates the environmental impact of the new technology by predicting possible hazardous nanoparticles "“ some of which are human-invented and do not occur in nature.

'It is extremely difficult to predict the exact risks that come with these particles without understanding how people are being exposed to them,' Dr Barnard says. 'So, instead our research sets out to predict the possible hazards in a given environment.'

'This then enables us to choose which nanomaterials are likely to be safest, both for people and the environment. By saying 'here's a size and shape that we can focus on', we can also help mitigate risk of harmful combinations.'

Nanomaterials consist of molecules only billionths of a meter in size. This gives them remarkable properties that ordinary materials do not possess "“ but it also means they can recombine with other substances in unexpected or unwanted ways and get into places where they can cause damage. Over 800 nano products are now on the world market offering solutions to problems ranging from sun protection to global warming, energy production, novel industrial products, better coatings and treatment of diseases.

However, their versatility causes them to be inherently unpredictable. Dr Barnard explains that nanoparticles are intrinsically unstable "“ unlike chemical systems where molecules have a fixed number of possible forms, the billions of atoms in a nanoparticle can have billions of possible combinations "“ some of those combinations, when exposed to particular environment, can have undesirable consequences, such as the emission of free radicals that are toxic to humans and other life.

One example is titania nanoparticles, commonly used in paints and self-cleaning surfaces. The safety of these nanomaterials has been hotly debated, as they emit potentially harmful free radicals when exposed to ultraviolet light, and are one of the topics of Dr Barnard's research.

'Variations in the shapes of nanoparticles mean that some will produce more free radicals than others "“ and so be potentially more harmful. Others can be quite safe. The key is to work out their optimal structures and the different ways to produce them. Some can be produced at higher temperatures to reduce the hazard; others may need different surface coatings.'

This also ensures that our attempts to make nanomaterials safe will not decrease their efficiency "“ the very reason they were developed in the first place. 'With the predictions, we can reassure industry that the nanomaterials will do what is required of them - and that they will not harm our health or the environment if used in the right quantities and in the right ways.'

Dr Amanda Barnard will give a presentation on her work at the Shine Dome in Canberra on Thursday 6 May 2010 at 12.15pm, as part of the Academy's annual Science at the Shine Dome meeting. Media are welcome to attend and interview participants.


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