In our new report on nano-silver, Friends of the Earth warned that not only could nano-silver’s use in food packaging, cutlery, cosmetics, household appliances, clothing and countless other products pose new toxicity risks, it could also leave us vulnerable to the development of virulent new bacteria.

In interviews with the ABC last week, the president of the Australian Society for Microbiology, Professor Hatch Stokes, and microbiologist Professor Peter Collignon of Canberra Hospital agreed with FoE that widespread use of antibacterial nano-silver could result in dangerous bacterial resistance. They warned that “needless” use of nano-silver in everyday consumer products could render it ineffective in a medical setting where it is actually useful.

Professor Stokes told Radio National’s AM program that just as the overuse of antibiotics has contributed to bacterial resistance to antibiotics, the over-use of silver poses the same risk. “I think there is a bit of an analogy here with the use of antibiotics. People know that in a medical context, antibiotics can be lifesaving but there has been a general rise in bacteria becoming resistant in recent years and clearly, under those circumstances, part of the reason for that is the overuse of antibiotics, particularly outside a clinical context… So what we have today is antibiotic-resistant bacteria are essentially making their way back through the food chain. I would be particularly worried that the evolutionary forces that are driving an increase in resistance to antibiotics could come into play here [in relation to nano-silver] as well.”

ABC Online reports that Professor Peter Collignon says “nano-silver is very useful in stopping the growth of bacteria on medical devices, without relying on antibiotics. He agrees nano-silver should be used sparingly to avoid resistance, as has occurred in the past with chemicals such as triclosan. “If you overuse [silver biocides] you do run the risk of getting cross-resistant bacteria developing that are not only resistant to silver, but to other compounds including antibiotics,” says Collignon.”The more you use, and the more widespread its use, the bigger that risk.”

Toxicologist, Dr Paul Wright of Royal Melbourne Institute of Technology told ABC Online that he agrees nano-silver shouldn’t be used “needlessly”. “”We don’t need nano-silver in every product,” says Wright, who is researching nano-silver with CSIRO, which he says hopes to use nano-silver in biosensors. He says different products shed different amounts of nano-silver, with some brands of socks losing it all after just four washes.”

To view the original news stories:

Call for control of nano-silver use (ABC Online) http://www.abc.net.au/science/articles/2009/06/12/2594441.htm?topic=latest

Green groups raise nanotechnology fears (Radio National’s AM) http://www.abc.net.au/news/stories/2009/06/12/2596423.htm