Australian scientists call for biological and toxicological testing of nanomaterials. 

Colin Raston and colleagues at the University of Western Australia have highlighted some recent advances in nanotechnology, from the use of nanomaterials in medicine to pollution clean-up. Raston has examined the health and ethical issues associated with the expanding nanotechnology industry. 

Raston calls for specific biological and toxicological testing of nano-sized structures. The toxicity of nanoparticles cannot be assessed by simply testing the material in bulk form, he said. 'It would be prudent to examine and address environmental and human health concerns, before the widespread adoption of specific [nano]technologies.'

For instance, in drug delivery applications, nanoparticles have been engineered to cross the blood-brain barrier. Raston asks: could other synthetic nanoparticles cross this barrier unintentionally, with detrimental effects to humans? Raston also points out that nanoparticles that can easily become airborne (and can therefore be inhaled) could pose a greater health threat than those that are incorporated into another material. 

Andre Nel, a pioneer in nanomedicine at the University of California, Los Angeles, agrees that introducing meaningful testing is important. 'While it is likely that most nanomaterials will be safe from a biological perspective, we need to demonstrate this is the case as a matter of precautionary principle,' he said. 'As a rational approach to this problem, we should establish predictable paradigms of toxicity that can help to classify these materials into those that are likely to be safe and those that could be hazardous.'

Alison Stoddart